CN109451647B

CN109451647B - High current diode cone ceramic package vacuum interface insulation structure

Info

Publication number: CN109451647B
Application number: CN201811295041.2A
Authority: CN
Inventors: 荀涛; 孙晓亮; 令钧溥; 贺军涛; 杨汉武; 陈冬群; 张军; 张建德; 钟辉煌
Original assignee: National University of Defense Technology
Current assignee: National University of Defense Technology
Priority date: 2018-11-01
Filing date: 2018-11-01
Publication date: 2020-08-07
Anticipated expiration: 2038-11-01
Also published as: CN109451647A

Abstract

The invention discloses a cone ceramic packaging vacuum interface insulation structure of a high current diode, and aims to improve the long-time vacuum-maintaining capacity and the withstand working voltage of the high current diode. The invention consists of a cathode base, a first voltage-sharing cover, a second voltage-sharing cover, an inner conductor, a first kovar ring, a cone angle insulator, a ceramic ring, a second kovar ring, a first flange, a second flange and a strong current diode outer cylinder; the cathode base, the first pressure equalizing cover, the second pressure equalizing cover, the inner conductor, the first kovar ring, the cone angle insulator, the ceramic ring, the second kovar ring and the first flange are located inside the outer cylinder of the high-current diode, the cathode base and the ceramic ring are packaged at the right end of the cone angle insulator through the first kovar ring, and the first flange is packaged at the left end of the cone angle insulator through the second kovar ring, so that integrated packaging is realized; according to the invention, through reasonably designing the electric field shielding structures such as the cone angle insulator, the voltage-sharing cover and the like, the distribution of the surface electric field and the surface magnetic field is optimized, the surface flashover probability of the interface is reduced, and the long-time vacuum-keeping capability and the working voltage tolerance of the high-current diode are improved.

Description

High current diode cone ceramic package vacuum interface insulation structure

Technical Field

The invention belongs to the technical field of high-current accelerators and pulse power, and particularly relates to a cone ceramic packaging vacuum interface insulation structure of a high-current diode.

Background

A high current diode is one of the key components in the field of high current accelerators and pulsed power technology for generating high current relativistic charged particle beams. The high current diode vacuum interface is used for isolating a liquid working medium in a pulse driving source from a particle beam load vacuum environment, and generally comprises a coaxial inner conductor, an outer conductor, an insulator for supporting and insulating between the inner conductor and the outer conductor, and a voltage-sharing structure for shielding and voltage-sharing. The vacuum interface will typically be subjected to a pulsed voltage in the order of hundreds of kV or even MV before the intense current particle beam is emitted. Due to the surface flashover discharge, the vacuum interface of the high current diode is often the limiting factor of high power current and the difficulty of system design.

The main factor influencing the operating performance of the vacuum interface of the high-current diode (including the insulation characteristic and the vacuum characteristic) is the material of the insulator and the configuration of the vacuum interface. In the aspect of insulator materials, organic polymers and nylon materials are often taken as representatives, and the insulator materials are characterized by low dielectric constant, easy processing, large gas release amount and unsuitability for high vacuum occasions; the ceramic material has the advantages of low gas outlet rate, high-temperature baking resistance, easiness in metal welding and the like, and the high-current diode vacuum interface integrally packaged by adopting ceramic and metal is favorable for improving the vacuum level of electron beam load and the system compactness level and reducing the assembly and connection links. In the aspect of vacuum interface configuration, the important function of a vacuum interface is insulation pulse high voltage, and for a ceramic dielectric vacuum interface, from the aspects of processing and yield, the configuration of a ceramic insulator is mostly flat, namely the ceramic plane and the power flow direction are equal to or slightly less than 90 degrees. The ceramic vacuum interface of the high-current diode with the structure is also successfully applied to driving electron beam loads of a high-power microwave source without a magnetic field, such as a magnetic insulated wire high-power microwave oscillator. For the electron beam load of the high-power microwave source with a magnetic field, such as a relativistic high-power backward wave tube, in order to avoid the bombardment of the backflow electrons on the surface of the ceramic insulator, the ceramic medium needs to adopt a large-angle (taper angle) design, namely the ceramic plane and the power flow direction are more than 90 degrees, and the configuration of the ceramic insulator is required to be changed from a flat plate type to a round table type. Compared with an organic high polymer material and a flat-plate type ceramic vacuum interface, the vacuum insulation interface with the ceramic-metal integrated package of the large-angle taper angle can effectively improve the vacuum degree level and the compactness degree of the load, and is simultaneously suitable for high-power and high-current electron beam loads without magnetic fields and with magnetic fields. The ceramic-metal integrated packaged high-current vacuum interface with the large-angle cone angle is used as an insulating support component, can be applied to the technical fields of high-current accelerators, pulse power systems, high-power microwave sources and the like, has good military and industrial benefits, and does not have a related technical scheme at present.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: aiming at the practical application requirement of a high-vacuum high-current diode driving a magnetic field high-power microwave source, the cone-angle ceramic packaging vacuum interface insulation structure of the high-current diode is provided, and by reasonably designing electric field shielding structures such as a cone-angle ceramic insulator and a voltage-sharing cover, the surface electric field and the surface magnetic field distribution are optimized, the surface flashover probability of an interface is reduced, and the long-time vacuum-maintaining capacity and the working voltage tolerance of the high-current diode driving the magnetic field high-power microwave source are improved.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention consists of a cathode base, a first voltage-sharing cover, a second voltage-sharing cover, an inner conductor, a first kovar ring, a cone angle insulator, a ceramic ring, a second kovar ring, a first flange, a second flange and a strong current diode outer cylinder. The cathode seat is of a rotational symmetry structure, and the central axis of the cathode seat is defined as an OO' axis of rotational symmetry; one end close to the inner conductor is a left end, and the other end close to the second voltage-sharing cover is a right end; the side close to the rotational symmetry axis OO 'is the inner side, and the side far away from the rotational symmetry axis OO' is the outer side. The left end of the second flange is externally connected with an outer conductor of the pulse power driving source through a threaded hole, and the right end of the second flange is connected with the left end of the outer cylinder of the high-current diode through the threaded hole; the cathode base, the first voltage-sharing cover, the second voltage-sharing cover, the inner conductor, the first kovar ring, the cone angle insulator, the ceramic ring, the second kovar ring and the first flange are all located inside the outer cylinder of the high-current diode. The left end of the inner conductor is externally connected with the inner conductor of the pulse power driving source through a claw-shaped structure, and the right end of the inner conductor is connected with the cathode base through threads; the right end of the cathode base is connected with the left end of the first pressure equalizing cover through threads; the right end of the first pressure equalizing cover is connected with the left end of the second pressure equalizing cover through threads; when the second voltage-sharing cover works, the right end of the second voltage-sharing cover is externally connected with a high-current diode cathode emitter; the outer side surface of the first kovar ring is connected with the inner surface and the left end surface of the ceramic ring through brazing, and the inner surface of the first kovar ring is connected with the outer surface of the cathode base through argon arc welding; the outer surface of the second kovar ring is connected with the inner surface of the first flange through argon arc welding; cone angle insulator right-hand member face and right-hand member face internal surface are connected through brazing with first kovar ring surface, and left end face surface are connected through brazing with second kovar ring internal surface, and cone angle insulator right-hand member passes through first kovar ring encapsulation negative pole seat and porcelain ring, and cone angle insulator left end passes through the first flange of second kovar ring encapsulation, finally realizes that the cone angle insulator is the main part, and negative pole seat, first kovar ring, porcelain ring, second kovar ring, first flange are the integration encapsulation of auxiliary part. The left end of the first flange is connected with the second flange through a threaded hole, and the right end of the first flange is connected with the outer cylinder of the high-current diode through a threaded hole.

The cathode base, the first voltage-sharing cover, the third voltage-sharing cover, the inner conductor, the first flange, the second flange and the outer cylinder of the high-current diode are made of nonmagnetic stainless steel materials, the first kovar ring and the second kovar ring are made of kovar alloy (namely 4J29 and 4J44 type iron-nickel-cobalt alloy), and the cone angle insulator and the ceramic ring are made of alumina ceramic materials.

The cone angle insulator is a hollow truncated cone structure with a right end face inner radius R₁Satisfy R₁＝R₅+Δ₁，R₅Is the first cylindrical radius, Delta, of the cathode base₁Is a deformation margin, Δ₁Generally 1-2 mm, the right end face outer radius R₂Satisfy R₂＝R₁+D₁，D₁The taper angle insulator sidewall thickness is determined by a hydrostatic strength P, typically greater than 1MPa absolute pressure, and a thickness D₁Satisfy the relation D₁Not less than 15 mm; the outer radius of the left end face is R₃Equal to the inner radius of the second flange, and the inner radius of the left end surface is R₄Satisfy R₄＝R₃-0.5D₁. For convenience of description, the surface of the taper angle insulator is a contact surface of the taper angle insulator with the right vacuum environment, and the surface direction is a generatrix direction of a truncated cone structure of the taper angle insulator. Taper angle insulator sidewall profile and power flow direction (for)

Represents) the included angle theta₁Determined by electrostatic field distribution, and the included angle theta is used for reducing the generation probability of surface flashover₁The following principles should be satisfied: the power lines in the outer cylinder (11) of the high-current diode are symmetrically distributed along an OO 'axis, and the power lines on the same side of the OO' axis form an included angle theta with the surface of the cone angle insulator (6)₂At an angle of 45 DEG and taperedThe angle insulator (6) is parallel to the taper angle insulator (6) along the magnetic force lines near the surface along the surface direction, the maximum electric field intensity of the taper angle insulator (6) along the surface is less than 30kV/cm, the electric field is distributed uniformly along the surface, and theta in the practical design₁Should be maintained between 125 deg. and 145 deg., and has a surface length of L₁The high voltage V of the working pulse of the high current diode packaged by the invention and the withstand electric field intensity E (generally 40-60 kV/cm, selected according to practical application conditions) of the cone angle insulator 6 are determined to satisfy the relation L₁≥V/E。

The cathode base is formed by coaxially connecting a first cylinder and a second cylinder, and the radius of the first cylinder is R₅Length of L₂(ii) a The second cylinder radius is R₆Length of L₃。R₅L determined according to the size of the flowing current, generally not less than 40mm₂The requirement of effectively fixing the cone angle insulator and facilitating assembly is met, and the relation L is generally met₂＝8Δ₁；R₆Determined according to the electric field effect of the shielding cathode three-binding-point region (cathode seat, vacuum and taper angle insulator junction), and satisfies the relation R₆＝R₅+4Δ₁；L₃Generally satisfies the relationship L₃＝10Δ₁. In order to optimize the surface electric field distribution at the boundary of the two-section cylindrical structure, the boundary of the second cylinder and the first cylinder is rounded. The rounding parameter is selected according to the simulation result of electrostatic field analysis software ANSYS (large-scale general Finite Element Analysis (FEA) software developed by ANSYS company in America is Computer Aided Engineering (CAE) software), and the electric field intensity of the edge surface of the cone angle insulator cathode triple junction area after rounding is required to be less than 30 kV/cm. A first threaded hole is dug in the center of the right end of the first cylinder, and the left end of the pressure equalizing cover is inserted into the first threaded hole; a second threaded hole is dug in the center of the left end of the second cylinder, and the right end of the inner conductor is inserted into the second threaded hole. Considering welding deformation factors, cutting off a ring on the outer surface of the right end of the first cylinder, wherein the thickness h of the ring is₁Satisfies the relation h₁＝1.5Δ₁Length l of₁Satisfies the relation l₁＝5Δ₁。

The first pressure equalizing cover is formed by coaxially connecting a third cylinder and a fourth cylinder. Radius of the third cylinder being R₇Length of L₄(ii) a The fourth cylinder has a radius of R₈Length of L₅. The left end of the third cylinder is firstly centered on the rotational symmetry axis OO', and an outer radius R is dug₇₁Inner radius of R₇₃Length L₄₁The ring of (2); then, an outer radius R is dug off by taking a rotational symmetry axis OO' as a center₇₂Inner radius of R₇₃Length L₄₂Such that the center leaves a first thin cylinder. The selection of the third cylinder parameter mainly meets the following relation according to the surface electric field effect and the actual assembly condition of the connection area of the shielding taper angle insulator and the cathode base: r₇＝R₇₁+7Δ₁，R₇₁＝R₂+3Δ₁，R₇₂＝R₇₁-2Δ₁，R₇₃The first thin cylinder is just inserted into the first threaded hole, and the assembly practical situation is considered, L₄＝L₂+2Δ₁，L₄₁＝L₄-2Δ₁，L₄₂＝2.5Δ₁. Radius of the fourth cylinder R₈Satisfies the relation R₈＝R₅+2Δ₁Length L₅The selection should take into consideration the actual assembly conditions, which generally satisfy L₅＝2L₂+(2～5)Δ₁Actually, the inner surface and the outer surface of the third cylinder are rounded, rounding parameters are selected according to an ANSYS simulation result of electrostatic field analysis software, the electric field intensity of an area of the cathode triple junction point of the taper angle insulator after rounding is required to be less than 30kV/cm along the surface, and the surface structure of the taper angle insulator is not influenced. The outer surface of the first thin cylinder is provided with an external thread, and the first thin cylinder is inserted into the first threaded hole and is in threaded connection with the first threaded hole. The fourth cylinder is provided with a first central hole with a radius equal to R and with a center of a rotational symmetry axis OO₇₃The first central hole has a depth h₂，h₂＝L₅-2Δ₁The first center hole is provided with internal threads, and a second thin cylinder of the second pressure equalizing cover is inserted into the first center hole and is in threaded connection with the second thin cylinder of the second pressure equalizing cover.

The design idea of the second pressure equalizing cover is basically consistent with that of the first pressure equalizing cover, and the second pressure equalizing cover is formed by coaxially connecting a fifth cylinder and a sixth cylinder. The fifth cylinder has a radius of R₁₀Length of L₇(ii) a The sixth cylinder has a radius of R₁₁Length of L₈. The left end of the fifth cylinder is firstly centered on the rotational symmetry axis OO', and an outer radius R is dug₁₀₁Inner radius of R₉Length L₆The ring of (2); then, an outer radius R is dug off by taking a rotational symmetry axis OO' as a center₁₀₁Inner radius of R₈Length L₇₁Such that a second thin cylinder remains centered. R₉Equal to the radius of the first central hole, R₁₀The relation R is satisfied based on that electrons emitted by the cathode can be effectively prevented from back-bombarding to the surface of the cone-angle insulator₁₀≥R_c+1.5cm, wherein R_cRadius of the cathode emitter (cylindrical) of the circumscribed high current diode L₇When selecting, the surface electric field of the conical angle insulator should be optimized, and the surface electric field enhancement of the cathode emission region connected with the right end face of the outer cylinder of the high-current diode and the downstream of the second voltage-sharing cover is avoided, so that no theoretical formula is described at present, and the value is generally 20-40 mm mainly according to design experience. The fifth cylinder is provided with a fillet structure so as to optimize the surface electric field distribution of the fifth cylinder, and the electric field intensity at the fillet and the right end surface of the outer cylinder of the high current diode is ensured to be less than 30kV/cm when the fillet is selected. Sixth cylinder radius R₁₁Satisfies the relation R₁₁＝R_c+0.5Δ₁Length L₈The value is generally 20-40 mm on the basis of not causing the electric field enhancement on the surface of the outer cylinder of the high-current diode. The interface of the fifth cylinder and the sixth cylinder adopts inclined plane connection instead of right angle connection, so that the surface electric field is reduced. R₉The second thin cylinder is just inserted into the first central hole. The second thin cylinder is provided with an external thread, and is inserted into the first center hole of the first pressure equalizing cover to realize threaded connection. The sixth cylinder takes a rotational symmetry axis OO' as a center, an internal thread is arranged on the inner side wall of a second center hole, and a high-current diode cathode emitter is inserted into the internal thread. Second center hole diameter h₃Equal to the diameter of the screw thread of the cathode emitter of the inserted high-current diode and the depth l₃Slightly larger than the thread length of the cathode emitter of the inserted high-current diode.

The inner conductor is sequentially formed by a seventh cylinder from left to rightThe first round platform and the eighth cylinder. The seventh cylinder has a radius of R₁₂Length L₉(ii) a The radius of the upper bottom surface of the first round platform is R₁₂The radius of the lower bottom surface is R₁₃Length L₁₀(ii) a The eighth cylinder has a radius of R₁₃Length L₁₁. The left end of the seventh cylinder is provided with a claw-shaped structure which is inserted into an inner conductor (cylindrical) of the pulse power driving source, and the processing method of the claw-shaped structure is as follows: firstly, digging a radius R at the left end of a seventh cylinder by taking a rotational symmetry axis OO' as a center₁₂₁Length L₉₁Then uniformly dividing the rest of the circular rings into 2N parts along the circumferential direction, cutting off one part at intervals, and respectively cutting off L parts along the direction of the rotational symmetry axis OO₉₁N is an integer generally having a value of 12-24 and a length of L₉₁Should satisfy the relationship L₉₁＝L₉-(2～5)Δ₁. Radius of the seventh cylinder R₁₂Equal to the radius of the inner conductor (cylindrical) of the pulse power drive source; the included angle theta between the side surface of the first circular truncated cone and OO₃Generally takes 40-60 degrees, and the radius R of the lower bottom surface₁₃Determined according to actual assembly requirements, generally satisfies the relation R₁₃＝(1.5～2)R₁₂Length L₁₀When selected, the relation L should be satisfied₁₀＝(R₁₃-R₁₂)/arctan(θ₃) Eighth cylinder length L₁₁The claw-shaped structure is inserted into the right ring of the external pulse power driving source inner conductor, the left end face of the claw-shaped structure is flush with the bottom of the right ring of the pulse power driving source inner conductor (one part of the pulse power driving source inner conductor is a cylinder, the joint of the pulse power driving source inner conductor and the claw-shaped structure is a ring, the place where the ring is connected with the cylinder is the bottom of the right ring of the pulse power driving source inner conductor), and the radius R is₁₃Local electric field intensity enhancement effect needs to be avoided, and the electric field intensity of the cathode triple junction area is controlled to be less than 30kV/cm, and the value is generally 30-50 mm. The right end of the eighth cylinder is firstly centered on the rotational symmetry axis OO', and an outer radius R is dug₁₃Inner radius of R₁₃₂Length L₁₁₁The ring of (2); then, an outer radius R is dug off by taking a rotational symmetry axis OO' as a center₁₃₁Inner radius of R₁₃₂Length L₁₁₂So that a third thin cylinder, with a radius R, remains in the center₁₃₂Equal to the second threaded hole radius, radius R₁₃₁Satisfies the relation R₁₃₁＝R₁₃₂+2Δ₁Length L₁₁₁The value is selected to satisfy the requirement of not contacting the taper angle insulator when the first round platform is assembled, and the length is L₁₁₂Substantially equal to L₁₁₁. The right end of the eighth cylinder adopts a fillet structure to optimize the surface electric field distribution, and the selection of the chamfering parameters is based on the standard that the electric field intensity of the edge surface of a large-cone-angle insulator in the simulation of the electrostatic field analysis software ANSYS is less than 30 kV/cm. The surface of the third thin cylinder is provided with an external thread which is inserted into a second threaded hole of the cathode base and is in threaded connection with the second threaded hole.

The first kovar ring is integrally in a circular ring shape and sequentially comprises a first circular ring, a second circular ring, a third circular ring and a fourth circular ring from left to right. The outer radius of the first ring is R₁₄Inner radius equal to R₅Length L₁₂₁(ii) a The outer radius of the second ring is equal to R₂Inner radius equal to R₅Length L₁₂₂(ii) a The outer radius of the third ring is equal to R₁₄Inner radius equal to R₅Length L₁₂₃(ii) a The outer radius of the fourth ring is R₁₅Inner radius equal to R₅Satisfies the relation R₁₅＝R₅+0.5Δ₁Length of L₁₂₄The first Kovar ring has an overall length of L₁₂＝L₁₂₁+L₁₂₂+L₁₂₃+L₁₂₄Each part has a length of L₁₂₁＝2Δ₁、L₁₂₂＝Δ₁、L₁₂₃＝3Δ₁、L₁₂₄＝2Δ₁，R₁₄The relation R is generally satisfied according to the actual assembly conditions of the first kovar ring and the taper angle insulator₅＜R₁₄≤R₅+3Δ₁. A first cylinder of the cathode base is inserted into the first kovar ring, and the first kovar ring is connected to the cathode base through argon arc welding; the first ring of the first kovar ring is inserted into the inner surface of the right end face of the taper angle insulator until the left end surface of the second ring is tightly attached to the right end face of the taper angle insulator, and the first ring and the second ring of the first kovar ring are connected to the right end of the taper angle insulator through brazing, so that the cathode base is connected to the right end of the taper angle insulator through the first kovar ringThe sealing leakage rate of the cone angle insulator and the sealing part of the cathode seat (namely the part brazed with the first Kovar ring) is required to be less than 5 × 10 according to the requirement of the working vacuum degree^-7Pa, L/s, the third ring provides the mechanical support that the second ring needs, and the function of fourth ring is that the package of reserving the encapsulation of brazing and argon arc welds the thermal deformation space of encapsulation, satisfies that the back porcelain ring internal surface of welding does not contact the fourth ring surface can.

The ceramic ring is circular, and the inner radius is equal to the inner radius R of the right end face of the cone angle insulator₁The outer radius is equal to the outer radius R of the right end face of the cone-angle insulator₂Length of L₁₃＝3Δ₁. The third ring of first kovar ring has been inserted to porcelain ring inside, hugs closely the second ring right-hand member face until porcelain ring left end face, and porcelain ring and first kovar ring are connected through brazing, and then encapsulate on the cone angle insulator. The ceramic ring mainly has the functions of ensuring the sealing uniformity and strength and offsetting the sealing stress.

The second kovar ring is in a ring shape, and the inner radius of the second kovar ring is equal to the inner radius R of the first flange₁₆The outer radius is equal to R₁₆+Δ₁Length equal to first flange length L₁₄The second Kovar ring is sleeved on the outer surface of the left end face of the taper angle insulator, the right end face of the second Kovar ring is flush with the right end of the outer surface of the left end face of the taper angle insulator, the second Kovar ring is connected with the taper angle insulator through brazing, so that the second Kovar ring is fixed at the left end of the taper angle insulator, the outer part of the second Kovar ring is coaxially nested in the first flange, the left end face of the second Kovar ring is flush with the left end face of the first flange, the outer surface of the second Kovar ring is welded with the inner surface of the first flange through argon arc welding, the second Kovar ring and the first flange are packaged together, and finally, the integrated packaging leakage rate of the taper angle insulator and the second Kovar ring at the sealing part is generally required to be less than 5 × 10 according to the requirement of the working vacuum degree^-7Pa.L/s。

The first flange is annular and has an inner radius of R₁₆And an outer radius of R₁₇，R₁₇Equal to the inner radius R of the fifth ring on the left end surface of the outer cylinder of the high-current diode₂₁₁Length L₁₄Equal to the left of the outer cylinder of the high current diodeFifth end ring length L₁₆₁The length h of the ring part cut off from the sixth ring₄And (4) summing. The left end face of the first flange is provided with 2 third threaded holes for being connected with the fourth threaded holes of the second flange. A first knife edge sealing groove is formed in the right end face of the first flange and used for placing a copper sealing ring used in assembly of the first flange and the outer cylinder of the high-current diode; the left end face of the first flange is provided with a first rectangular sealing groove for placing a fluorine rubber ring or a copper sealing ring used during assembly of the first flange and the second flange, and the working vacuum level of the system is improved. Coaxial nested second kovar ring has in the first flange, and first flange left end face and second kovar ring left end face parallel and level, first flange internal surface and second kovar ring surface pass through argon arc and weld and be connected.

The second flange is annular and has an outer radius of R₁₉，R₁₉Equal to the outer radius R of the outer tube of the high-current diode₂₀Inner radius of R₁₈In order to optimize the surface electric field, R, at the junction of the cone angle insulator, the second kovar ring and the first flange₁₈Satisfies the relation R₁₈＝R₄-5Δ₁Length of L₁₅The relation L is generally satisfied by selecting the outer conductor of the pulse power driving source connected with the left side according to the practical requirement₁₅＝2.5Δ₁. The inner surface of the second flange optimizes the surface electric field distribution through a rounding structure, and rounding parameters meet the condition that the surface electric field intensity at a chamfering position is less than 30 kV/cm. A fourth threaded hole is formed in the right end face of the second flange and used for assembling the first flange; and a fifth threaded hole is formed in the left end face and is used for being in threaded assembly connection with a sixth threaded hole of the outer cylinder of the high-current diode and an outer conductor of the upstream pulse power driving source.

The outer cylinder of the high current diode is annular as a whole and sequentially comprises a fifth circular ring, a sixth circular ring, a second circular table, a seventh circular ring and an eighth circular ring from left to right. The outer radius of the fifth ring is R₂₀Inner radius of R₂₁₁Length L₁₆₁(ii) a The outer radius of the sixth ring is R₂₁₂Inner radius of R₂₁₃Length L₁₆₂(ii) a The outer radius of the left end surface of the second round table is R₂₁₂The inner radius of the left end face is R₂₁₁Right end face outer radius of R₂₀Right end face inner radius is R₂₁Length of L₁₆₃The included angle between the side surface of the circular truncated cone and the rotational symmetry axis OO' is theta₄(ii) a The outer radius of the seventh ring is R₂₀Inner radius of R₂₁Length L₁₆₄(ii) a The outer radius of the eighth ring is R₂₀Inner radius of R₂₁₄Length L₁₆₅The total length of the outer cylinder of the high current diode is L₁₆＝L₁₆₁+L₁₆₂+L₁₆₃+L₁₆₄+L₁₆₅. Outer radius of the fifth ring R₂₀Equal to the radius of the outer conductor (cylindrical) of the pulse drive source connected at the left end, and the inner radius R₂₁₁Satisfies the relation R₂₁₁＝R₂₀-7.5Δ₁Length of L₁₆₁＝5Δ₁(ii) a The left end surface of the sixth ring is dug off to form a ring with an outer radius of R₂₁₁Inner radius of R₂₁₃Length h of₄The outer radius R of the sixth ring₂₁₂Satisfies the relation R₂₁₂＝R₂₀-5Δ₁Inner radius R₂₁₃Satisfies the relation R₂₁₃＝R₂₁₂-8Δ₁Length L₁₆₂＝6Δ₁(ii) a Radius R in right end face of second round platform₂₁Satisfies the relation R₂₁＝R₂₀-Δ₁Length L₁₆₃Meet the included angle theta between the surface of the circular truncated cone and the central shaft OO₄45 degrees, seventh ring length L₁₆₄Determining according to actual assembly conditions, and generally taking 40-60 mm; inner radius R of eighth ring₂₁₄Satisfies the relation R₂₁₄＝R₂₀-20Δ₁Length L₁₆₅Satisfies the relationship L₁₆₅＝5Δ₁. During actual design, the internal space of the outer cylinder of the high-current diode is ensured to be large enough so as to reserve space for subsequently placing a getter and a vacuum supply pump and optimize electric field distribution in the outer cylinder of the high-current diode. And a sixth threaded hole connected with the second flange is formed in the left end face of the outer cylinder of the high-current diode, and a second rectangular sealing groove is formed in the position close to the sixth threaded hole and used for mounting a fluorine rubber ring sealing ring. And a second knife edge sealing groove is formed in the left end of the sixth circular ring, and a copper sealing ring is installed in the second knife edge sealing groove and used for sealing the joint of the second flange and the outer cylinder of the high-current diode. The eighth ring is provided with a seventh threaded hole for connecting the high power on the right sideA microwave source. The right end face of the eighth ring is further provided with a plurality of air exhaust ports to facilitate subsequent operations such as vacuumizing.

When the invention works, the right side of the taper angle insulator is usually in a vacuum environment, and the left side of the taper angle insulator is a pulse power source working medium such as liquid or SF₆A gas.

The invention can achieve the following technical effects:

the taper angle insulator is used as a main body structure, the right end of the taper angle insulator is packaged with the cathode base and the ceramic ring through the first kovar ring, the left end of the taper angle insulator is packaged with the first flange through the second kovar ring, and further the integrated packaging of the high-current diode ceramic vacuum interface insulation structure is realized through the thread structure, so that the vacuum degree level of the high-current diode under the conditions of single pulse and repetition frequency pulse with the pulse width of tens of ns and hundreds of kV is improved, and the along-plane electric field strength of the high-current diode vacuum interface insulation structure under the magnetic field condition is improved by optimizing the taper angle and the along-plane length of the taper angle insulator, adding the pressure equalizing cover, chamfering the surface and other measures. The invention can effectively improve the vacuum degree level of the high current diode and the integral compactness degree of the system under the conditions of magnetic field, pulse width of dozens of ns and repetition frequency pulse high voltage of hundreds of kV magnitude.

Drawings

FIG. 1 is a schematic view of the present invention in cross section along the front of an OO' overall structure;

FIG. 2(a) is a front cross-sectional view of the taper angle insulator 6 of the present invention taken along OO'; fig. 2(b) is a half-sectional view (above OO') of the power line profile; FIG. 2(c) is a half-sectional view (portion above OO') of the distribution of magnetic lines along the surface;

FIG. 3 is an enlarged sectional view of the cathode base 1 of the present invention taken along OO' in the forward direction;

FIG. 4 is an enlarged cross-sectional view of the first pressure-equalizing jacket 2 of the present invention taken along OO' in the forward direction;

FIG. 5 is an enlarged cross-sectional view of the second pressure-equalizing jacket 3 of the present invention taken along OO' in the forward direction;

fig. 6(a) is an enlarged cross-sectional view of the inner conductor 4 of the present invention taken along OO' in a forward direction; FIG. 6(b) is a left side view of the inner conductor 4 of the present invention;

FIG. 7 is an enlarged cross-sectional view of the first kovar ring 5 of the present invention taken along OO';

FIG. 8 is an enlarged sectional view of the porcelain ring 7 of the present invention taken along OO' in the forward direction;

FIG. 9 is a front cross-sectional view of the first flange 9 of the present invention taken along OO';

FIG. 10 is a front cross-sectional view of the second flange 10 of the present invention taken along OO';

FIG. 11 is a front sectional view of the outer barrel 11 of the high current diode of the present invention taken along OO';

fig. 12 is an experimental output waveform of the present invention.

Detailed Description

The following further describes embodiments of the present invention with reference to the accompanying drawings.

FIG. 1 is a schematic view of the present invention in a front cross-section along the overall structure of OO'. The high-current diode cathode base comprises a cathode base 1, a first voltage-sharing cover 2, a second voltage-sharing cover 3, an inner conductor 4, a first kovar ring 5, a taper angle insulator 6, a ceramic ring 7, a second kovar ring 8, a first flange 9, a second flange 10 and a high-current diode outer barrel 11. The cathode base is of a rotational symmetry structure, and the central axis of the cathode base 1 is defined as a rotational symmetry axis OO'; one end close to the inner conductor 4 is a left end, and one end close to the second voltage-sharing cover 3 is a right end; the side close to the rotational symmetry axis OO 'is the inner side, and the side far away from the rotational symmetry axis OO' is the outer side.

The left end of the second flange 10 is externally connected with an outer conductor of the pulse power driving source through a threaded hole, and the right end of the second flange is connected with the left end of the outer cylinder 11 of the high-current diode through a threaded hole; the cathode base 1, the first voltage-sharing cover 2, the second voltage-sharing cover 3, the inner conductor 4, the first kovar ring 5, the taper angle insulator 6, the porcelain ring 7, the second kovar ring 8 and the first flange 9 are all located inside the outer cylinder 11 of the high-current diode. The left end of the inner conductor 4 is externally connected with an inner conductor of a pulse power driving source through a claw-shaped structure 4011, and the right end of the inner conductor is connected with the cathode base 1 through threads; the right end of the cathode base 1 is connected with the left end of the first pressure equalizing cover 2 through threads; the right end of the first pressure equalizing cover 2 is connected with the left end of the second pressure equalizing cover 3 through threads; when the second voltage-sharing cover 3 works, the right end is externally connected with a cathode emitter of a high-current diode; the outer side surface of the first kovar ring 5 is connected with the inner surface and the left end surface of the ceramic ring 7 through brazing, and the inner surface of the first kovar ring 5 is connected with the outer surface of the cathode base 1 through argon arc welding; the outer surface of the second kovar ring 8 is connected with the inner surface of the first flange 9 through argon arc welding; the right end face 601 and the right end face inner surface 602 of the cone angle insulator 6 are connected with the outer surface of the first kovar ring 5 through brazing, the left end face 603 and the left end face outer surface 604 are connected with the inner surface of the second kovar ring 8 through brazing, the right end of the cone angle insulator 6 encapsulates the cathode base 1 and the ceramic ring 7 through the first kovar ring 5, the left end of the cone angle insulator 6 encapsulates the first flange 9 through the second kovar ring 8, and finally the cone angle insulator 6 is used as a main body, and the cathode base 1, the first kovar ring 5, the ceramic ring 7, the second kovar ring 8 and the first flange 9 are integrally encapsulated by auxiliary parts; the left end of the first flange 9 is connected with the second flange 10 through a threaded hole, and the right end of the first flange is connected with the outer cylinder 11 of the high current diode through a threaded hole.

The cathode base 1, the first voltage-sharing cover 2, the third voltage-sharing cover 3, the inner conductor 4, the first flange 9, the second flange 10 and the outer cylinder 11 of the high-current diode are made of non-magnetic stainless steel materials, the first kovar ring 5 and the second kovar ring 8 are made of kovar alloys (namely 4J29 and 4J44 type iron nickel cobalt alloys), and the cone angle insulator 6 and the ceramic ring 7 are made of alumina ceramic materials.

FIG. 2(a) is a front cross-sectional view of the taper angle insulator 6 of the present invention taken along OO'; fig. 2(b) is a half-sectional view (above OO') of the power line profile; fig. 2(c) is a half-sectional view (portion above OO') of the distribution of magnetic lines along the surface. The cone angle insulator 6 is a hollow truncated cone structure with a right end face inner radius R₁Satisfy R₁＝R₅+Δ₁，R₅Is the radius, delta, of the first cylinder 101 of the cathode base 1₁Is a deformation margin, Δ₁Generally 1-2 mm, the right end face outer radius R₂Satisfy R₂＝R₁+D₁，D₁The taper angle insulator 6 sidewall thickness is determined by the hydrostatic strength P, which is typically greater than 1MPa absolute pressure, and the thickness D₁Satisfy the relation D₁Not less than 15 mm; the outer radius of the left end face is R₃Equal to the inner radius of the second flange 9 and the inner radius of the left end surface is R₄Satisfy R₄＝R₃-0.5D₁. For convenience of description, the surface of the taper angle insulator 6 is defined as a contact surface of the taper angle insulator 6 with the right vacuum environment, and the surface direction is a generatrix direction of a truncated cone structure of the taper angle insulator 6. Taper angle insulator 6 sidewall profile and power flowFlow direction (by)

Represents) the included angle theta₁Determined by electrostatic field distribution, and the included angle theta is used for reducing the generation probability of surface flashover₁The following principles should be satisfied: power line (for) in outer cylinder (11) of high current diode

Shown) are symmetrically distributed along an OO 'axis, and the power line on the same side of the OO' axis forms an included angle theta with the cone angle insulator (6) along the surface₂The insulator (6) with 45 degree angle of taper angle is along the near magnetic line of force (using)

Representing) the parallel taper angle insulator (6) along the surface direction, the maximum electric field intensity of the taper angle insulator (6) along the surface is less than 30kV/cm, and the electric field is distributed as uniformly as possible along the surface; theta in actual design₁Should be maintained between 125 deg. and 145 deg., and has a surface length of L₁The high voltage V of the working pulse of the high current diode packaged by the invention and the withstand electric field intensity E (generally 40-60 kV/cm, selected according to practical application conditions) of the cone angle insulator 6 are determined to satisfy the relation L₁≥V/E。

FIG. 3 is an enlarged sectional view of the cathode base 1 of the present invention taken along OO' in the forward direction; the cathode base 1 is formed by coaxially connecting a first cylinder 101 and a second cylinder 102, wherein the radius of the first cylinder 101 is R₅Length of L₂(ii) a The second cylinder 102 has a radius R₆Length of L₃。R₅L determined according to the size of the flowing current, generally not less than 40mm₂It suffices to be able to effectively fix the taper angle insulator 6 and facilitate assembly, and generally satisfies the relation L₂＝8Δ₁；R₆Determined according to the electric field effect of the shielded cathode three-joint area 100 (the junction of the cathode base 1 and the vacuum and cone angle insulator 6) and satisfies the relation R₆＝R₅+4Δ₁；L₃Generally satisfies the relationship L₃＝10Δ₁. In order to optimize the surface electric field distribution at the boundary of the two-section cylindrical structure, the boundary 103 between the second cylinder 102 and the first cylinder 101 is rounded. Fillet parameter according toAnd selecting an ANSYS simulation result of electrostatic field analysis software, wherein the intensity of the electric field along the surface of the cone angle insulator 6 cathode three-binding-point region 100 is required to be less than 30kV/cm after rounding. A first threaded hole 1011 is dug in the center of the right end of the first cylinder 101, and the left end of the pressure equalizing cover 2 is inserted into the first threaded hole 1011; a second threaded hole 1021 is dug in the center of the left end of the second cylinder 102, and the right end of the inner conductor 4 is inserted into the second threaded hole 1021. Considering welding deformation factors, a ring is cut off from the outer surface of the right end of the first cylinder 101, and the thickness h of the ring₁Satisfies the relation h₁＝1.5Δ₁Length l of₁Satisfies the relation l₁＝5Δ₁。

FIG. 4 is an enlarged cross-sectional view of the first pressure-equalizing jacket 2 of the present invention taken along OO' in the forward direction; the first pressure equalizing cover 2 is formed by coaxially connecting a third cylinder 201 and a fourth cylinder 202. The third cylinder 201 has a radius R₇Length of L₄(ii) a The fourth cylinder 202 has a radius R₈Length of L₅. The left end of the third cylinder 201 is first centered on the rotational symmetry axis OO', and an outer radius R is cut off₇₁Inner radius of R₇₃Length L₄₁The ring of (2); then, an outer radius R is dug off by taking a rotational symmetry axis OO' as a center₇₂Inner radius of R₇₃Length L₄₂So that a first thin cylinder 2011 is left in the center. The parameters of the third cylinder 201 are selected mainly according to the surface electric field effect and the actual assembly condition of the connection area of the shielding taper angle insulator 6 and the cathode base 1, and the following relations are satisfied: r₇＝R₇₁+7Δ₁，R₇₁＝R₂+3Δ₁，R₇₂＝R₇₁-2Δ₁，R₇₃Satisfy that first thin cylinder 2011 just inserts first screw hole 1011, consider the assembly actual conditions, L₄＝L₂+2Δ₁，L₄₁＝L₄-2Δ₁，L₄₂＝2.5Δ₁. Radius R of fourth cylinder 202₈Satisfies the relation R₈＝R₅+2Δ₁Length L₅The selection should take into consideration the actual assembly conditions, which generally satisfy L₅＝2L₂+(2～5)Δ₁Actually, the inner and outer surfaces of the third cylinder 201 are rounded, and the parameters of the rounding are divided according to the electrostatic fieldAnd (4) selecting analysis software ANSYS simulation results, wherein the intensity of the electric field along the surface of the three-joint-point area 100 of the taper angle insulator 6 cathode after rounding is required to be less than 30kV/cm, and the surface structure of the taper angle insulator 6 is not influenced. The outer surface of the first thin cylinder 2011 is provided with external threads, and the first thin cylinder 2011 is inserted into the first threaded hole 1011 and is in threaded connection with the first threaded hole 1011. The fourth cylinder 202 is centered on the rotational axis of symmetry OO' and is hollowed with a first central hole 2021, the radius of the first central hole 2021 is equal to R₇₃The depth of the first central hole 2021 is h₂，h₂＝L₅-2Δ₁The first center hole 2021 is provided with an internal thread, and a second thin cylinder 3011 of the second voltage-sharing cover 3 is inserted into the first center hole 2021 and is in threaded connection with the second thin cylinder 3011 of the second voltage-sharing cover 3.

FIG. 5 is an enlarged cross-sectional view of the second pressure-equalizing jacket 3 of the present invention taken along OO' in the forward direction; the design idea of the second pressure equalizing cover 3 is basically the same as that of the first pressure equalizing cover 2, and the second pressure equalizing cover 3 is formed by coaxially connecting a fifth cylinder 301 and a sixth cylinder 302. The fifth cylinder 301 has a radius R₁₀Length of L₇(ii) a The sixth cylinder 303 has a radius R₁₁Length of L₈. The left end of the fifth cylinder 301 is first centered on the axis of rotational symmetry OO', and an outer radius R is cut off₁₀Inner radius of R₉Length L₆The ring of (2); then, an outer radius R is dug off by taking a rotational symmetry axis OO' as a center₁₀₁Inner radius of R₈Length L₇₁So that a second thin cylinder 3011 remains in the center. R₉Equal to the radius, R, of the first central bore 2021₁₀The relation R is satisfied based on that electrons emitted by the cathode can be effectively prevented from back-bombarding to the surface of the cone-angle insulator 6₁₀≥R_c+1.5cm, wherein R_cRadius of the cathode emitter (cylindrical) of the high current diode L₅When selecting, the surface electric field of the cone angle insulator 6 should be optimized and the surface electric field enhancement of the cathode emission region connected with the right end face of the outer cylinder 11 of the high current diode and the downstream of the second voltage-sharing cover 3 should be avoided, and at present, no theoretical formula is described, and the method is mainly based on design experience. Fifth cylinder 301 is provided with fillet structure in order to optimize fifth cylinder 301 surface electric field distribution, and the fillet should be guaranteed in the time of selecting the fillet and the strong currentThe electric field intensity of the right end surface of the diode outer cylinder 11 is less than 30 kV/cm. Sixth cylinder 302 radius R₁₁Satisfies the relation R₁₁＝R_c+0.5Δ₁Length L₈The electric field on the surface of the outer cylinder 11 of the high current diode is not enhanced. The interface of the fifth cylinder 301 and the sixth cylinder 302 adopts an inclined plane connection instead of a right-angle connection, so that the surface electric field is reduced. R₉So that the second thin cylinder 3011 is just inserted into the first central hole 2021. The second thin cylinder 3011 is provided with an external thread and is inserted into the first central hole 2021 of the first equalizing cover 2 to realize a threaded connection. The sixth cylinder 302 is centered on the rotational symmetry axis OO', a second central hole 3021 is dug, and an internal thread is arranged on the inner side wall of the second central hole 3021, into which a high current diode cathode emitter is inserted. Second center bore 3021 diameter h₃Equal to the diameter of the screw thread of the cathode emitter of the inserted high-current diode and the depth l₃Slightly larger than the thread length of the cathode emitter of the inserted high-current diode.

Fig. 6(a) is an enlarged cross-sectional view of the inner conductor 4 of the present invention taken along OO' in a forward direction; FIG. 6(b) is a left side view of the inner conductor 4 of the present invention; the seventh cylinder 401 has a radius R₁₂Length L₉(ii) a The radius of the upper bottom surface of the first circular truncated cone 402 is R₁₂The radius of the lower bottom surface is R₁₃Length L₁₀(ii) a The eighth cylinder 403 has a radius R₁₃Length L₁₁. The left end of the seventh cylinder 401 is provided with a claw-shaped structure 4011 inserted into an inner conductor (cylindrical) of the pulse power drive source, and the claw-shaped structure 4011 is processed as follows: firstly, a radius R is dug off by taking a rotational symmetry axis OO' as a center at the left end of a seventh cylinder 401₁₂₁Length L₉₁Then uniformly dividing the rest of the circular rings into 2N parts along the circumferential direction, cutting off one part at intervals, and respectively cutting off L parts along the direction of the rotational symmetry axis OO₉₁N is an integer generally having a value of 12-24 and a length of L₉₁Should satisfy the relationship L₉₁＝L₉-(2～5)Δ₁. Radius R of seventh cylinder 401₁₂Equal to the radius of the inner conductor (cylindrical) of the pulse power drive source; an included angle theta between the upper bottom surface and the side surface of the first circular truncated cone 402₃Generally takes 40-60 degrees, and the radius R of the lower bottom surface₁₃According to actual assembly requirementsAlways, the relation R is satisfied₁₃＝(1.5～2)R₁₂Length L₁₀When selected, the relation L should be satisfied₁₀＝(R₁₃-R₁₂)/arctan(θ₃) Length L of eighth cylinder 403₁₁The claw-shaped structure (4011) is inserted into the right ring of the inner conductor of the external pulse power driving source, the left end surface of the claw-shaped structure is flush with the bottom of the right ring of the inner conductor of the pulse power driving source, and the radius R is₁₃Local electric field intensity enhancement effect needs to be avoided, and the 100 electric field intensity of the cathode triple junction area is controlled to be less than 30kV/cm, and the value is generally 30-50 mm. The right end of the eighth cylinder 403 is first centered on the axis of rotational symmetry OO', with an outer radius R₁₃Inner radius of R₁₃₂Length L₁₁₁The ring of (2); then, an outer radius R is dug off by taking a rotational symmetry axis OO' as a center₁₃₁Inner radius of R₁₃₂Length L₁₁₂Leaving a third thin cylinder 4031 in the center, radius R₁₃₂Equal to the radius of the second threaded hole 121, radius R₁₃₁Satisfies the relation R₁₃₁＝R₁₃₂+2Δ₁Length L₁₁₁The value is such that the first truncated cone 402 does not contact the taper angle insulator 6 during assembly, and the length is L₁₁₂Substantially equal to L₁₁₁. The right end of the eighth cylinder 403 adopts a fillet structure to optimize the surface electric field distribution, and the selection of the chamfering parameters is based on the standard that the electric field intensity of the large-taper-angle insulator 6 along the surface is less than 30kV/cm in the simulation of the electrostatic field analysis software ANSYS. The third thin cylinder 4031 has external threads on its surface, and is inserted into the second threaded hole 1021 of the cathode holder 1 and screwed into the second threaded hole 1021.

FIG. 7 is an enlarged cross-sectional view of the first kovar ring 5 of the present invention taken along OO'; the first kovar ring 5 is annular as a whole and includes a first ring 501, a second ring 502, a third ring 503, and a fourth ring 504 in sequence from left to right. The first ring 501 has an outer radius R₁₄Inner radius of R₅Length L₁₂₁(ii) a The second ring 502 has an outer radius R₂Inner radius equal to R₅Length L₁₂₂(ii) a The outer radius of the third ring 503 is equal to R₁₄Inner radius equal to R₅Length L₁₂₃(ii) a Outer radius of fourth ring 504Is R₁₅Inner radius equal to R₅Satisfies the relation R₁₅＝R₅+0.5Δ₁Length of L₁₂₄The first kovar ring 5 has an overall length of L₁₂＝L₁₂₁+L₁₂₂+L₁₂₃+L₁₂₄Each part has a length of L₁₂₁＝2Δ₁、L₁₂₂＝Δ₁、L₁₂₃＝3Δ₁、L₁₂₄＝2Δ₁，R₁₄Selected according to the actual assembly conditions of the first kovar ring 5 and the cone angle insulator 6, and generally satisfies the relationship R₅＜R₁₄≤R₅+3Δ₁Inserting the first cylinder 101 of the cathode base 1 into the first kovar ring 5, connecting the first kovar ring 5 on the cathode base 1 through argon arc welding, inserting the left end of the first kovar ring 5 into the inner surface 602 of the right end surface of the cone angle insulator 6 through the first circular ring 501 until the left end surface of the second circular ring 502 and the right end surface 601 of the cone angle insulator 6, connecting the first circular ring 501 and the second circular ring 502 of the first kovar ring 5 with the cone angle insulator 6 through brazing, finally encapsulating the first kovar ring 5 on the cone angle insulator 6 at the right end of the cone angle insulator 6, encapsulating the cathode base 1 on the cone angle insulator 6 through the first kovar ring 5, and according to the requirement of the working vacuum degree, the requirement of the sealing leakage rate of the sealing part of the cone angle insulator 6 and the cathode base 1 (namely the sealing part of the cone angle insulator 6 and the first kovar ring 5) is less than 5 × 10^-7Pa, L/s, a third ring 503 provides mechanical support for the second ring 502, and a thermal deformation space for braze welding packaging and argon arc welding packaging is reserved for the fourth ring 504, so that the inner surface of the ceramic ring 7 does not contact with the outer surface of the fourth ring 504 after welding.

FIG. 8 is an enlarged sectional view of the porcelain ring 7 of the present invention taken along OO' in the forward direction; the porcelain ring 7 is circular, and the inner radius is equal to the inner radius R of the right end face of the cone angle insulator 6₁The outer radius is equal to the outer radius R of the right end face of the cone angle insulator 6₂Length of L₁₃＝3Δ₁. The third circular ring 503 of the first kovar ring 5 is inserted into the ceramic ring 7 until the left end face of the ceramic ring 7 is tightly attached to the right end face of the second circular ring 502, and the ceramic ring 7 is connected with the first kovar ring 5 through brazing so as to be packaged on the cone angle insulator 6. The ceramic ring 7 mainly has the functions of ensuring the sealing uniformity and strength and offsetting the sealing stress.

The second kovar ring 8 is circular ring-shaped, and the inner radius is equal to the inner radius R of the first flange 9₁₆The outer radius is equal to R₁₆+Δ₁A length equal to the length L of the first flange 9₁₄The second Kovar ring 8 is sleeved on the outer surface 604 of the left end face of the taper angle insulator 6, the right end face of the second Kovar ring 8 is flush with the outer surface 604 of the left end face of the taper angle insulator 6, the second Kovar ring 8 is connected with the taper angle insulator 6 through brazing, so that the second Kovar ring 8 is fixed at the left end of the taper angle insulator 6, the second Kovar ring 8 is coaxially nested in the first flange 9, the left end face of the second Kovar ring 8 is flush with the left end face of the first flange 9, the outer surface of the second Kovar ring 8 is welded with the inner surface of the first flange 9 through argon arc welding, the second Kovar ring 8 is packaged with the first flange 9, finally, the taper angle insulator 6 is packaged with the second Kovar ring 8 and the first flange 9 integrally at the left end of the taper angle insulator 6, and the sealing leak rate of the sealing part of the taper angle insulator 6 and the second Kovar ring 8 is generally required to be^-7Pa.L/s。

FIG. 9 is a front cross-sectional view of the first flange 9 of the present invention taken along OO'; the first flange 9 is annular and has an inner radius R₁₆And an outer radius of R₁₇，R₁₇Equal to the inner radius R of a fifth circular ring 1101 on the left end surface of the outer cylinder 11 of the high-current diode₂₁₁Length of L₁₅，L₁₄Equal to the length L of a fifth ring 1101 on the left end surface of the strong current diode outer cylinder 11₁₆₁The length h of the ring part cut off from the sixth ring 1102₄And (4) summing. The left end face of the first flange 9 is provided with 2 third threaded holes 901 for connecting with the fourth threaded holes 1001 of the second flange 10. A first knife edge sealing groove 902 is formed in the right end face of the first flange 9 and used for placing a copper sealing ring used in assembly of the first flange 9 and the outer cylinder 11 of the high-current diode; the left end face of the first flange 9 is provided with a first rectangular sealing groove 903 for placing a fluorine rubber ring or a copper sealing ring used in the assembly of the first flange 9 and the second flange 10, so that the working vacuum level of the system is improved. Coaxial nested second kovar ring 8 in the

first flange

9, 9 left end faces of first flange and 8 left end faces parallel and level of second kovar ring, and 9 internal surfaces of first flange and 8 surfaces of second kovar ring are connected through argon arc welding.

FIG. 10 is a cross-sectional view of the second flange 10 of the present invention taken along the line OOTo a cross-sectional view; the second flange 10 is annular and has an outer radius R₁₉，R₁₉Equal to the outer radius R of the outer cylinder 11 of the high current diode₂₀Inner radius of R₁₈In order to optimize the surface electric field, R, at the junction of the cone angle insulator 6 with the second kovar ring 8 and the first flange 9₁₈Satisfies the relation R₁₈＝R₄-5Δ₁Length of L₁₅The relation L is generally satisfied by selecting the outer conductor of the pulse power driving source connected with the left side according to the practical requirement₁₅＝2.5Δ₁. The distribution of the surface electric field is optimized on the inner surface of the second flange 10 through a rounding structure, and the rounding parameters meet the condition that the electric field intensity of the surface at the chamfering position is less than 30 kV/cm. A fourth threaded hole 1001 is formed in the right end face of the second flange 10 and used for assembling the first flange 9; the left end face is provided with a fifth threaded hole 1002 for being in threaded assembly connection with a sixth threaded hole 1106 of the high-current diode outer barrel 11 and an outer conductor of the upstream pulse power driving source.

FIG. 11 is a front sectional view of the outer barrel 11 of the high current diode of the present invention taken along OO'; the high current diode outer cylinder 11 is annular as a whole, and includes a fifth ring 1101, a sixth ring 1102, a second truncated cone 1103, a seventh ring 1104 and an eighth ring 1105 in this order from left to right. The fifth ring 1101 has an outer radius R₂₀Inner radius of R₂₁₁Length L₁₆₁(ii) a The sixth ring 1102 has an outer radius R₂₁₂Inner radius of R₂₁₃Length L₁₆₂(ii) a The outer radius of the left end face of the second round platform 1103 is R₂₁₂The inner radius of the left end face is R₂₁₁Right end face outer radius of R₂₀Right end face inner radius is R₂₁Length of L₁₆₃The included angle between the side surface of the circular truncated cone and the rotational symmetry axis OO' is theta₄(ii) a The outer radius of the seventh ring 1104 is R₂₀Inner radius of R₂₁Length L₁₆₄(ii) a The eighth ring 1105 has an outer radius of R₂₀Inner radius of R₂₁₄Length L₁₆₅The total length of the outer cylinder of the high current diode is L₁₆＝L₁₆₁+L₁₆₂+L₁₆₃+L₁₆₄+L₁₆₅. Fifth Ring 1101 outer radius R₂₀Equal to the radius of the outer conductor (cylindrical) of the pulse drive source connected at the left end, and the inner radius R₂₁₁Satisfies the relation R₂₁₁＝R₂₀-7.5Δ₁Length of L₁₆₁＝5Δ₁(ii) a The left end face of the sixth ring 1102 is dug to have an outer radius R₂₁₁Inner radius of R₂₁₃Length h of₄The sixth ring 1102 has an outer radius R₂₁₂Satisfies the relation R₂₁₂＝R₂₀-5Δ₁Inner radius R₂₁₃Satisfies the relation R₂₁₃＝R₂₁₂-8Δ₁Length L₁₆₂＝6Δ₁(ii) a Radius R in right end face of second round platform 1103₂₁Satisfies the relation R₂₁＝R₂₀-Δ₁Length L₁₆₃Meet the included angle theta between the surface of the circular truncated cone and the central shaft OO₄45 degrees, length L of seventh ring 1104₁₆₄Determining according to actual assembly conditions, and generally taking 40-60 mm; inner radius R of eighth ring 1105₂₁₄Satisfies the relation R₂₁₄＝R₂₀-20Δ₁Length L₁₆₅Satisfies the relationship L₁₆₅＝5Δ₁. During actual design, the internal space of the outer cylinder 11 of the high current diode is ensured to be large enough to reserve space for subsequently placing a getter and a vacuum supply pump and optimize the distribution of an electric field in the outer cylinder 11 of the high current diode. A sixth threaded hole 1106 connected with the second flange 10 is formed in the left end face of the outer cylinder 11 of the high current diode, and a second rectangular sealing groove 1107 is arranged close to the sixth threaded hole 1106 to mount a fluorine rubber ring sealing ring. The left end of the sixth ring 1102 is provided with a second knife edge sealing groove 1108, and a copper sealing ring is installed in the second knife edge sealing groove 1108 and used for sealing the joint of the second flange 9 and the strong current diode outer cylinder 11. The eighth ring 1105 is provided with a seventh threaded hole 1109 for connection to a right side high power microwave source. The right end face of the eighth ring 1105 is further provided with a plurality of air extraction ports to facilitate subsequent operations such as vacuum extraction.

According to the structure, a high-current diode ceramic packaging vacuum interface insulation structure (embodiment 1) is prepared, and integrated assembly of the high-current diode ceramic packaging vacuum interface insulation structure with a magnetic field high-power microwave source is achieved. Example 1 the corresponding dimensions are: r₁＝20mm，R₂＝32mm，R₃＝151.5mm，R₄＝145.5mm，R₅＝18.5mm，R₆＝24.5mm，R₇＝47mm，R₇₁＝36.5mm，R₇₂＝33.5mm，R₇₃＝10mm，R₈＝21.5mm，R₉＝10mm，R₁₀＝106mm，R₁₀₁＝86mm，R₁₁＝30mm，R₁₂＝26mm，R₁₂₁＝25mm，R₁₃＝42mm，R₁₃₁＝26mm，R₁₃₂＝20mm，R₁₄＝20.25mm，R₁₅＝19.25mm，R₁₆＝151.5mm，R₁₇＝210mm，R₁₈＝235mm，R₁₉＝138mm，R₂₀＝235mm，R₂₁＝233.5mm，R₂₁₁＝223.75mm，R₂₁₂＝227.5mm，R₂₁＝215.5mm，R₂₁₄＝205mm，R_c＝29.25mm，L₁＝166mm，L₂＝12mm，L₃＝15mm，L₄＝15mm，L₄₁＝12mm，L₄₂＝3.75mm，L₅＝41.5mm，L₆＝8mm，L₇＝30mm，L₇₁＝15mm，L₈＝30mm，L₉＝25mm，L₉₁＝20mm，L₁₀＝33mm，L₁₁＝87mm，L₁₁₁＝9.5mm，L₁₁₂＝10mm，L₁₂＝12mm，L₁₂₁＝3mm，L₁₂₂＝1.5mm，L₁₂₃＝4.5mm，L₁₂₄＝3mm，L₁₃＝4.5mm，L₁₄＝18.5mm，L₁₅＝3.75mm，L₁₆＝72mm，L₁₆₁＝7.5mm，L₁₆₂＝9mm，L₁₆₃＝7.5mm，L₁₆₄＝40.5mm，L₁₆₅＝7.5mm，Δ₁＝1.5mm，D₁＝12mm，θ₁＝135°，θ₂＝45°，θ₃＝45°，θ₄＝45°，h₁＝2.25mm，h₂＝12mm，h₃＝10mm，h₄＝1.5mm，l₁7.5 mm. FIG. 12 is a graph of current and voltage waveforms of the present invention collected by an oscilloscope in example 1 under the experimental conditions of 630kV of working pulse high voltage V of the high current diode, 10Hz of repetition frequency of the working pulse high voltage, and 0.7T of applied magnetic field of the high current diode, wherein C1 and C2 are respectively the voltage waveform and the current waveform, the ordinate is the amplitude, each grid is 1V, and the abscissa isAs time, each grid is 200 ns. from figure 12, it can be seen that the voltage and current waveform consistency and repeatability are good, the pulse width shortening phenomenon does not occur, the voltage pulse width is greater than 60ns, the average voltage amplitude after conversion exceeds 630kV, the surface flashover phenomenon does not occur, the vacuum degree of the high-power microwave source is better than 5 × 10^-4Pa, and the whole system is compact. Therefore, the vacuum degree level of the high-current diode under the conditions of single pulse with pulse width of tens of ns and hundreds of kV and repetition frequency pulse is improved, and the surface withstanding electric field intensity of the high-current diode vacuum interface insulation structure under the condition of a magnetic field is improved.

The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention.

Claims

1. A high current diode cone ceramic package vacuum interface insulation structure is characterized in that the high current diode cone ceramic package vacuum interface insulation structure is a rotational axis symmetric structure and consists of a cathode base (1), a first voltage-sharing cover (2), a second voltage-sharing cover (3), an inner conductor (4), a first kovar ring (5), a cone angle insulator (6), a ceramic ring (7), a second kovar ring (8), a first flange (9), a second flange (10) and a high current diode outer barrel (11); defining the central axis of the cathode base (1) as a rotational symmetry axis OO ', wherein one end close to the inner conductor (4) is a left end, one end close to the second voltage-sharing cover (3) is a right end, one side close to the rotational symmetry axis OO ' is an inner side, and one side far away from the rotational symmetry axis OO ' is an outer side; the left end of the second flange (10) is externally connected with an outer conductor of the pulse power driving source through a threaded hole, and the right end of the second flange is connected with the left end of the strong current diode outer cylinder (11) through a threaded hole; the cathode base (1), the first voltage-sharing cover (2), the second voltage-sharing cover (3), the inner conductor (4), the first kovar ring (5), the taper angle insulator (6), the porcelain ring (7), the second kovar ring (8) and the first flange (9) are all positioned inside the outer cylinder (11) of the high-current diode; the left end of the inner conductor (4) is externally connected with an inner conductor of a pulse power driving source, and the right end of the inner conductor is connected with the cathode base (1) through threads; the right end of the cathode base (1) is connected with the left end of the first pressure equalizing cover (2) through threads; the right end of the first pressure equalizing cover (2) is connected with the left end of the second pressure equalizing cover (3) through threads; the right end of the second voltage-sharing cover (3) is externally connected with a cathode emitter of a high-current diode; the outer side surface of the first kovar ring (5) is connected with the inner surface and the left end surface of the ceramic ring (7) through brazing, and the inner surface of the first kovar ring (5) is connected with the outer surface of the cathode base (1) through argon arc welding; the outer surface of the second kovar ring (8) is connected with the inner surface of the first flange (9) through argon arc welding; the right end face (601) and the right end face inner surface (602) of the cone angle insulator (6) are connected with the outer surface of the first kovar ring (5) through brazing, the left end face (603) and the left end face outer surface (604) of the cone angle insulator (6) are connected with the inner surface of the second kovar ring (8) through brazing, the right end of the cone angle insulator (6) is used for encapsulating the cathode base (1) and the ceramic ring (7) through the first kovar ring (5), the left end of the cone angle insulator (6) is used for encapsulating the first flange (9) through the second kovar ring (8), and finally the cone angle insulator (6) is used as a main body, and the cathode base (1), the first kovar ring (5), the ceramic ring (7), the second kovar ring (8) and the first flange (9) are used for integrally encapsulating auxiliary parts; the left end of the first flange (9) is connected with the second flange (10) through a threaded hole, and the right end of the first flange is connected with the outer cylinder (11) of the high current diode through a threaded hole;

the cone angle insulator (6) is of a hollow truncated cone structure, and the inner radius R of the right end face₁Satisfy R₁＝R₅+Δ₁，R₅Is the radius, delta, of the first cylinder (101) of the cathode base (1)₁The right end face outer radius R is the deformation allowance₂Satisfy R₂＝R₁+D₁，D₁Is the taper angle insulator (6) sidewall thickness, determined by the hydrostatic strength P; the outer radius of the left end face is R₃Equal to the inner radius of the second flange (9), and the inner radius of the left end surface is R₄Satisfy R₄＝R₃-0.5D₁(ii) a The surface of the taper angle insulator (6) is a contact surface of the taper angle insulator and a right vacuum environment, and the surface direction is a generatrix direction of a truncated cone structure of the taper angle insulator (6); the included angle theta formed by the side wall surface of the taper angle insulator (6) and the flow direction of the power flow₁Determined by the electrostatic field distribution, [ theta ]₁Satisfies the following conditions: the power lines in the outer cylinder (11) of the high-current diode are symmetrically distributed along an OO 'axis, and the power lines on the same side of the OO' axis form an included angle theta with the surface of the cone angle insulator (6)₂The taper angle insulator (6) forms a 45 DEG angle along the magnetic force lines near the surface, the taper angle insulator (6) is parallel to the taper angle insulator (6) along the surface direction, and the maximum electric field intensity of the taper angle insulator (6) along the surface is less than 30kV/cm and the electric field is uniformly distributed along the surface, and the length of the surface is L₁Satisfies the relationship L₁V/E is more than or equal to V, V is the high voltage of the working pulse of the high current diode, and E is the tolerant electric field intensity of the cone-angle insulator (6);

the cathode base (1) is formed by coaxially connecting a first cylinder (101) and a second cylinder (102), and the radius of the first cylinder (101) is R₅Length of L₂(ii) a The second cylinder (102) has a radius R₆Length of L₃；R₅According to the magnitude of the circulating current, L₂The requirement of effectively fixing the cone angle insulator (6) and facilitating the assembly can be met, R₆The method is determined according to the electric field effect of a shielding cathode triple-joint area (100), namely the junction of a cathode base (1) and a vacuum cone-angle insulator (6); a first threaded hole (1011) is dug in the center of the right end of the first cylinder (101), and the left end of the pressure equalizing cover (2) is inserted into the first threaded hole (1011); a second threaded hole (1021) is dug in the center of the left end of the second cylinder (102), and the right end of the inner conductor (4) is inserted into the second threaded hole (1021);

the first pressure equalizing cover (2) is formed by coaxially connecting a third cylinder (201) and a fourth cylinder (202); the radius of the third cylinder (201) is R₇Length of L₄(ii) a The radius of the fourth cylinder (202) is R₈Length of L₅(ii) a The left end of the third cylinder (201) is firstly centered on the rotational symmetry axis OO', and an outer radius R is dug₇₁Inner radius of R₇₃Length L₄₁The ring of (2); then, an outer radius R is dug off by taking a rotational symmetry axis OO' as a center₇₂Inner radius of R₇₃Length L₄₂Such that a first thin cylinder (2011) remains centered; the outer surface of the first thin cylinder (2011) is provided with external threads, and the first thin cylinder (2011) is inserted into the first threaded hole (1011) and is in threaded connection with the first threaded hole (1011); the fourth cylinder (202) is provided with a first central hole (2021) centered on the rotational symmetry axis OO', and the radius of the first central hole (2021) is equal to R₇₃The first center hole (2021) is provided with internal threads, and a second thin cylinder (3011) of the second voltage-sharing cover (3) is inserted into the first center hole (2021) and is in threaded connection with the second thin cylinder (3011) of the second voltage-sharing cover (3);

the second pressure equalizing cover (3) is formed by a fifth cylinder (301) and a sixth cylinder (302) which are coaxialAre connected to form the product; the radius of the fifth cylinder (301) is R₁₀Length of L₇(ii) a The sixth cylinder (302) has a radius of R₁₁Length of L₈(ii) a The left end of the fifth cylinder (301) is firstly centered on the rotational symmetry axis OO', and an outer radius R is dug₁₀₁Inner radius of R₉Length L₆The ring of (2); then, an outer radius R is dug off by taking a rotational symmetry axis OO' as a center₁₀₁Inner radius of R₈Length L₇₁Such that a second thin cylinder (3011) remains centred; r₉Equal to the radius R of the first central hole (2021)₇₃，R₁₀L is selected based on the fact that electrons emitted from the cathode are effectively prevented from being bombarded onto the surface of the cone-angle insulator (6)₇When selecting, the surface electric field of the cone angle insulator (6) is optimized and the surface electric field enhancement of the cathode emission region connected with the right end face of the outer cylinder (11) of the high-current diode and the downstream of the second voltage-sharing cover (3) is avoided, and the length is L₈The surface electric field of the outer cylinder (11) of the high current diode is not enhanced; the interface of the fifth cylinder (301) and the sixth cylinder (302) is connected by adopting an inclined plane; r₉The second thin cylinder (3011) is just inserted into the first central hole (2021); the second thin cylinder (3011) is provided with external threads and is inserted into a first central hole (2021) of the first pressure equalizing cover (2) to realize threaded connection; the sixth cylinder (302) takes a rotational symmetry axis OO' as a center, a second central hole (3021) is dug, and the depth and the diameter of the second central hole (3021) are respectively l₃And h₃The inner side wall of the second central hole (3021) is provided with internal threads, and a high-current diode cathode emitter is inserted into the internal threads;

the inner conductor (4) consists of a seventh cylinder (401), a first circular table (402) and an eighth cylinder (403) from left to right in sequence; the radius of the seventh cylinder (401) is R₁₂Length L₉(ii) a The radius of the upper bottom surface of the first round platform (402) is R₁₂The radius of the lower bottom surface is R₁₃Length L₁₀(ii) a The eighth cylinder (403) has a radius of R₁₃Length L₁₁(ii) a The left end of the seventh cylinder (401) is provided with a claw-shaped structure (4011) which is inserted into an inner conductor of the pulse power drive source; radius R of seventh cylinder (401)₁₂Equal to the radius of the inner conductor of the pulse power driving source; the side surface of the first round platform (402) forms an included angle with OOθ₃Radius of lower bottom surface R₁₃Determined according to actual assembly requirements, the length L of the eighth cylinder (403)₁₁The claw-shaped structure (4011) is inserted into the right ring of the inner conductor of the external pulse power driving source, the left end surface of the claw-shaped structure is flush with the bottom of the right ring of the inner conductor of the pulse power driving source, and the radius R is₁₃The value is taken to avoid the local electric field intensity enhancement effect and control the electric field intensity of the cathode triple junction area (100) to be less than 30 kV/cm; the right end of the eighth cylinder (403) is firstly centered on the rotational symmetry axis OO', and an outer radius R is dug₁₃Inner radius of R₁₃₂Length L₁₁₁The ring of (2); then, an outer radius R is dug off by taking a rotational symmetry axis OO' as a center₁₃₁Inner radius of R₁₃₂Length L₁₁₂Leaving a third thin cylinder (4031) in the centre; the surface of the third thin cylinder (4031) is provided with an external thread, is inserted into a second threaded hole (1021) of the cathode base (1), and is in threaded connection with the second threaded hole (1021);

the first kovar ring (5) is annular as a whole and sequentially comprises a first circular ring (501), a second circular ring (502), a third circular ring (503) and a fourth circular ring (504) from left to right; the outer radius of the first circular ring (501) is R₁₄Inner radius equal to R₅Length L₁₂₁(ii) a The outer radius of the second ring (502) is equal to R₂Inner radius equal to R₅Length L₁₂₂(ii) a The outer radius of the third ring (503) is equal to R₁₄Inner radius equal to R₅Length L₁₂₃(ii) a The outer radius of the fourth ring (504) is R₁₅Inner radius equal to R₅Length of L₁₂₄The first kovar ring (5) has an overall length L₁₂＝L₁₂₁+L₁₂₂+L₁₂₃+L₁₂₄(ii) a A first cylinder (101) of the cathode base (1) is inserted into the first kovar ring (5), and the first kovar ring (5) is connected to the cathode base (1) through argon arc welding; the first ring (501) of the first kovar ring (5) is inserted into the inner surface (602) of the right end face of the cone angle insulator (6) until the left end surface of the second ring (502) is attached to the right end face (601) of the cone angle insulator (6), the first ring (501) and the second ring (502) of the first kovar ring (5) are connected to the right end of the cone angle insulator (6) through brazing, and therefore the cathode base (1) is connected to the right end of the cone angle insulator (6) through the second ringA kovar ring (5) encapsulated on the cone angle insulator (6); the third circular ring (503) provides mechanical support required by the second circular ring (502), and the fourth circular ring (504) has the function of reserving a thermal deformation space for braze welding packaging and argon arc welding packaging, so that the inner surface of the ceramic ring (7) is not contacted with the outer surface of the fourth circular ring (504) after welding;

the porcelain ring (7) is annular, and the inner radius is equal to the inner radius R of the right end face of the cone angle insulator (6)₁The outer radius is equal to the outer radius R of the right end surface of the cone angle insulator (6)₂Length of L₁₃(ii) a A third circular ring (503) of the first kovar ring (5) is inserted into the ceramic ring (7) until the left end face of the ceramic ring (7) is tightly attached to the right end face of the second circular ring (502), and the ceramic ring (7) is connected with the first kovar ring (5) through brazing and then packaged on the taper angle insulator (6);

the second kovar ring (8) is annular, and the inner radius is equal to the inner radius R of the first flange (9)₁₆The outer radius is equal to R₁₆+D₁A length equal to the length L of the first flange (9)₁₄(ii) a The second Kovar ring (8) is sleeved on the outer surface (604) of the left end face of the cone angle insulator (6), the right end face of the second Kovar ring (8) is flush with the right end of the outer surface (604) of the left end face of the cone angle insulator (6), and the second Kovar ring (8) is connected with the cone angle insulator (6) through brazing, so that the second Kovar ring (8) is fixed at the left end of the cone angle insulator (6); the second Kovar ring (8) is coaxially nested in the first flange (9), the left end face of the second Kovar ring (8) is flush with the left end face of the first flange (9), the outer surface of the second Kovar ring (8) is welded with the inner surface of the first flange (9) through argon arc welding, and the second Kovar ring (8) and the first flange (9) are packaged together; finally, the cone angle insulator (6) is integrally packaged on the second kovar ring (8) and the first flange (9) at the left end of the cone angle insulator (6);

the first flange (9) is annular and has an inner radius R₁₆And an outer radius of R₁₇，R₁₇Equal to the inner radius R of a fifth circular ring (1101) on the left end surface of the strong current diode outer cylinder (11)₂₁₁Length of L₁₄(ii) a 2 third threaded holes (901) are formed in the left end face of the first flange (9) and are used for being connected with a fourth threaded hole (1001) of the second flange (10); a first knife edge sealing groove (902) is arranged on the right end face of the first flange (9) and is used for placing the first flange (9) and the outer cylinder (11) of the high current diode during assemblyCopper seal rings for use; a first rectangular sealing groove (903) is formed in the left end face of the first flange (9) and used for placing a fluorine rubber ring or a copper sealing ring used when the first flange (9) and the second flange (10) are assembled; a second kovar ring (8) is coaxially nested in the first flange (9);

the second flange (10) is annular and has an outer radius R₁₉，R₁₉Equal to the outer radius R of the outer cylinder (11) of the high current diode₂₀Inner radius of R₁₈Length of L₁₅(ii) a A fourth threaded hole (1001) is formed in the right end face of the second flange (10) and used for assembling the first flange (9); the left end face of the high-current diode outer barrel is provided with a fifth threaded hole (1002) which is used for being in threaded assembly connection with a sixth threaded hole (1106) of the high-current diode outer barrel (11) and an outer conductor of an upstream pulse power driving source;

the high-current diode outer cylinder (11) is annular as a whole and sequentially comprises a fifth circular ring (1101), a sixth circular ring (1102), a second circular table (1103), a seventh circular ring (1104) and an eighth circular ring (1105) from left to right; the outer radius of the fifth ring (1101) is R₂₀Inner radius of R₂₁₁Length L₁₆₁(ii) a The outer radius of the sixth ring (1102) is R₂₁₂Inner radius of R₂₁₃Length L₁₆₂(ii) a The outer radius of the left end surface of the second round platform (1103) is R₂₁₂The inner radius of the left end face is R₂₁₁Right end face outer radius of R₂₀Right end face inner radius is R₂₁Length of L₁₆₃The included angle between the side surface of the circular truncated cone and the rotational symmetry axis OO' is theta₄(ii) a The outer radius of the seventh ring (1104) is R₂₀Inner radius of R₂₁Length L₁₆₄(ii) a The outer radius of the eighth ring (1105) is R₂₀Inner radius of R₂₁₄Length L₁₆₅The total length of the outer cylinder (11) of the high current diode is L₁₆＝L₁₆₁+L₁₆₂+L₁₆₃+L₁₆₄+L₁₆₅(ii) a The left end surface of the sixth ring (1102) is dug to form an outer radius R₂₁₁Inner radius of R₂₁₃Length h of₄The ring of (2); a sixth threaded hole (1106) connected with the second flange (10) is formed in the left end face of the outer cylinder (11) of the high-current diode, and a second rectangular sealing groove (1107) is formed in the position close to the sixth threaded hole (1106) to install a fluorine rubber ring sealing ring; sixth ring(1102) A second knife edge sealing groove (1108) is formed in the left end, and a copper sealing ring is installed in the second knife edge sealing groove (1108) and used for sealing the joint of a second flange (9) and a strong current diode outer barrel (11); the eighth ring (1105) is provided with a seventh threaded hole (1109) for connecting a right high-power microwave source; the right end face of the eighth ring (1105) is also provided with a plurality of air extraction ports.

2. The high current diode cone ceramic package vacuum interface insulation structure of claim 1, characterized in that the cathode base (1), the first voltage-sharing cover (2), the third voltage-sharing cover (3), the inner conductor (4), the first flange (9), the second flange (10) and the outer cylinder (11) of the high current diode are made of non-magnetic stainless steel material, the first kovar ring (5) and the second kovar ring (8) are made of kovar alloy, and the cone angle insulator (6) and the ceramic ring (7) are made of alumina ceramic material.

3. The high current diode taper ceramic package vacuum interface insulator structure of claim 2, wherein said kovar alloy is fe-ni-co alloy type 4J29 and 4J 44.

4. The high current diode cone ceramic package vacuum interface insulation structure of claim 1, wherein said deformation margin Δ₁Taking 1-2 mm, enduring static pressure intensity P larger than 1MPa absolute pressure, and taper angle insulator (6) side wall thickness D₁Satisfies D₁≥15mm；θ₁The value is between 125 and 145 degrees; the withstanding electric field intensity E of the cone angle insulator (6) is 40-60 kV/cm.

5. The high current diode cone ceramic package vacuum interface insulation structure of claim 1, wherein R is₅Not less than 40mm, L₂Satisfy L₂＝8Δ₁，R₆Satisfy R₆＝R₅+4Δ₁，L₃Satisfy L₃＝10Δ₁。

6. The high-current diode cone ceramic package vacuum interface insulation structure as claimed in claim 1, wherein the boundary (103) between the second cylinder (102) and the first cylinder (101) and the inner and outer surfaces of the third cylinder (201) are rounded, the rounding parameters are selected according to the simulation result of electrostatic field analysis software ANSYS, and the electric field intensity along the surface of the cathode triple-junction region (100) of the cone angle insulator (6) after rounding is required to be less than 30 kV/cm; the fifth cylinder (301) is provided with a fillet structure, and the fillet parameters meet the requirement that the electric field intensity of the surfaces of the fifth cylinder (301) and the right end surface of the strong current diode outer cylinder (11) is less than 30 kV/cm; the right end of the eighth cylinder (403) adopts a fillet structure, and the fillet parameters meet the requirement that the electric field intensity of the large-taper-angle insulator (6) along the surface in ANSYS simulation of electrostatic field analysis software is less than 30 kV/cm; and the inner surface of the second flange (10) is chamfered, and the electric field intensity of the inner surface of the second flange (10) is less than 30kV/cm after chamfering according to the chamfering parameters.

7. The high current diode cone ceramic package vacuum interface insulation structure of claim 1, wherein a ring is cut off from the outer surface of the right end of the first cylinder (101), and the ring has a thickness h₁Satisfies the relation h₁＝1.5Δ₁Length l of₁Satisfies the relation l₁＝5Δ₁。

8. The high current diode cone ceramic package vacuum interface insulation structure of claim 1, characterized in that the third cylinder (201) parameters satisfy the following relationship: r₇＝R₇₁+7Δ₁，R₇₁＝R₂+3Δ₁，R₇₂＝R₇₁-2Δ₁，R₇₃The first thin cylinder (2011) is just inserted into the first threaded hole (1011), L₄＝L₂+2Δ₁，L₄₁＝L₄-2Δ₁，L₄₂＝2.5Δ₁(ii) a Radius R of fourth cylinder (202)₈Satisfies the relation R₈＝R₅+2Δ₁Length L₅The depth h of the first central hole (2021) is selected by considering the mechanical strength and the assembly practice₂Satisfy h₂＝L₅-2Δ₁。

9. The high current diode cone ceramic package vacuum interface insulation structure of claim 1, characterized in that the parameters of the second voltage-sharing cover (3) satisfy: r₁₀Satisfy R₁₀≥R_c+1.5cm，R_cRadius of external high-current diode cathode emitter L₇The value is between 20 and 40 mm; r₁₁Satisfy R₁₁＝R_c+0.5Δ₁Length L₈The value is between 20 and 40 mm; the diameter h of the second central hole (3021)₃Equal to the diameter of the screw thread of the cathode emitter of the inserted high-current diode and with the depth of l₃Is longer than the thread length of the cathode emitter of the inserted high-current diode.

10. The high current diode cone ceramic package vacuum interface insulation structure of claim 1, wherein the processing method of the claw-like structure (4011) is as follows: firstly, digging a radius R at the left end of a seventh cylinder (401) by taking a rotational symmetry axis OO' as a center₁₂₁Length L₉₁Then uniformly dividing the rest of the circular rings into 2N parts along the circumferential direction, cutting off one part at intervals, and respectively cutting off L parts along the direction of the rotational symmetry axis OO₉₁N is an integer and has a value of 12-24 and a length of L₉₁Satisfies the relationship L₉₁＝L₉-(2～5)Δ₁。

11. The high current diode cone ceramic package vacuum interface insulation structure of claim 1, characterized in that the parameters of the inner conductor (4) satisfy: theta₃The value is 40-60 degrees, and the radius R of the lower bottom surface₁₃Satisfy R₁₃＝(1.5～2)R₁₂Length L₁₀Satisfy L₁₀＝(R₁₃-R₁₂)/arctan(θ₃) Length L of eighth cylinder (403)₁₁Equal to the distance between the invention and the inner conductor of the external pulse power driving source during actual assembly and the radius R₁₃Generally taking a value of 30-50 mm; radius R₁₃₂Equal to the radius of the second threaded hole (1021), radius R₁₃₁Satisfy R₁₃₁＝R₁₃₂+2Δ₁Length L₁₁₁The value is such that the first round table (402) does not contact the taper angle insulator (6) during assembly, and the length is L₁₁₂Equal to L₁₁₁。

12. The high current diode cone ceramic package vacuum interface insulation structure of claim 1, wherein the first kovar ring (5) parameter satisfies R₁₅＝R₅+0.5Δ₁，L₁₂₁＝2Δ₁、L₁₂₂＝Δ₁、L₁₂₃＝3Δ₁、L₁₂₄＝2Δ₁，R₁₄Satisfies the relation R₅＜R₁₄≤R₅+3Δ₁。

13. The high current diode cone ceramic package vacuum interface insulation structure of claim 1, wherein the sealing leakage rate of the sealing part of the cone angle insulator (6) and the cathode base (1) and the second kovar ring (8) is less than 5 × 10^- ⁷Pa.L/s。

14. The high current diode cone ceramic package vacuum interface insulation structure of claim 1, wherein the length of the ceramic ring (7) is L₁₃＝3Δ₁The length L of the first flange (9)₁₄Equal to the length L of a fifth ring (1101) on the left end surface of the strong current diode outer cylinder (11)₁₆₁The length h of the part of the sixth ring (1102) where the ring is cut off₄Summing; the inner radius R of the second flange (10)₁₈Satisfy R₁₈＝R₄-5Δ₁Length L₁₅Satisfy L₁₅＝2.5Δ₁。

15. The high current diode cone ceramic package vacuum interface insulation structure of claim 1, wherein said fifth ring (1101) has an outer radius R₂₀Equal to the radius of the outer conductor of the pulse drive source connected at the left end, and the inner radius R₂₁₁Satisfies the relation R₂₁₁＝R₂₀-7.5Δ₁Length L₁₆₁＝5Δ₁(ii) a Outer radius R of sixth ring (1102)₂₁₂Satisfy R₂₁₂＝R₂₀-5Δ₁Inner radius R₂₁₃Satisfy R₂₁₃＝R₂₁₂-8Δ₁Length L₁₆₂＝6Δ₁(ii) a The right end surface inner radius R of the second round platform (1103)₂₁Satisfy R₂₁＝R₂₀-Δ₁Length L₁₆₃Meet the included angle theta between the surface of the circular truncated cone and the central shaft OO₄45 degree seventh ring (1104) length L₁₆₄Taking 40-60 mm; inner radius R of eighth ring (1105)₂₁₄Satisfy R₂₁₄＝R₂₀-20Δ₁Length L₁₆₅Satisfy L₁₆₅＝5Δ₁。

16. The high current diode cone ceramic package vacuum interface insulation structure as claimed in claim 1, wherein the right side of the cone angle insulator (6) is a vacuum environment, and the left side of the cone angle insulator (6) is a pulse power source working medium.

17. The high current diode cone ceramic package vacuum interface insulation structure of claim 1, wherein θ is θ₁Is maintained between 125 deg. and 145 deg..