CN112485276A - Hundred kilovolt ultrafast electron diffraction device - Google Patents
Hundred kilovolt ultrafast electron diffraction device Download PDFInfo
- Publication number
- CN112485276A CN112485276A CN202011281330.4A CN202011281330A CN112485276A CN 112485276 A CN112485276 A CN 112485276A CN 202011281330 A CN202011281330 A CN 202011281330A CN 112485276 A CN112485276 A CN 112485276A
- Authority
- CN
- China
- Prior art keywords
- sample
- electron gun
- chamber
- sample chamber
- ultrafast
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
- G01N23/20—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by using diffraction of the radiation by the materials, e.g. for investigating crystal structure; by using scattering of the radiation by the materials, e.g. for investigating non-crystalline materials; by using reflection of the radiation by the materials
- G01N23/20058—Measuring diffraction of electrons, e.g. low energy electron diffraction [LEED] method or reflection high energy electron diffraction [RHEED] method
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
- G01N23/20—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by using diffraction of the radiation by the materials, e.g. for investigating crystal structure; by using scattering of the radiation by the materials, e.g. for investigating non-crystalline materials; by using reflection of the radiation by the materials
- G01N23/20008—Constructional details of analysers, e.g. characterised by X-ray source, detector or optical system; Accessories therefor; Preparing specimens therefor
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N23/00—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00
- G01N23/20—Investigating or analysing materials by the use of wave or particle radiation, e.g. X-rays or neutrons, not covered by groups G01N3/00 – G01N17/00, G01N21/00 or G01N22/00 by using diffraction of the radiation by the materials, e.g. for investigating crystal structure; by using scattering of the radiation by the materials, e.g. for investigating non-crystalline materials; by using reflection of the radiation by the materials
- G01N23/20008—Constructional details of analysers, e.g. characterised by X-ray source, detector or optical system; Accessories therefor; Preparing specimens therefor
- G01N23/20025—Sample holders or supports therefor
Landscapes
- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Analysing Materials By The Use Of Radiation (AREA)
Abstract
The invention discloses a flexible compact hundred-kilovolt ultrafast electron diffraction device which comprises an electron gun body, wherein the electron gun body comprises an electron gun chamber, a direct current photocathode electron gun body inside the electron gun chamber, a magnetic lens, a sample chamber, a pumping light back incidence unit, a Faraday cylinder chamber and an imaging device, a sample displacement table is fixedly installed on the side surface of the sample chamber, a sample fixing device is fixedly arranged inside the sample displacement table, and a titanium sublimation pump, an ion pump, a molecular pump and a vacuum measuring device are fixedly arranged at the bottom of the sample chamber. This flexible compact hundred kilovolts ultrafast electron diffraction device, through adopting the direct current photocathode electron gun body, the sample frame is nimble multi-functional, makes whole set of device can carry out multiple experiment and survey, and the change can be dismantled to the sample frame, and some devices that need concatenate between electron gun body and sample room can be connected on the sample pole, have reduced the complexity of system, have further shortened the negative pole apart from the sample distance.
Description
Technical Field
The invention relates to the technical field of ultrafast electron diffraction, in particular to a flexible compact hundred-kilovolt ultrafast electron diffraction device.
Background
The ultrafast electron diffraction technology is a technology for realizing time-resolved pumping detection by using ultrashort pulse laser, and its principle is that a light-splitting device is used to divide laser pulse into two beams, one beam is used to excite the cathode of an electron gun body to produce probe electrons, and the other beam is used to pump a reaction region, and the probe electrons are detected in advance or delayed by controlling the optical path difference of the two beams of laser, so as to realize the measurement at different times.
With the development of time, the ultrafast electron diffraction technology has been developed, schemes such as transmission diffraction, surface reflection diffraction, shadow imaging, ultrafast transmission electron microscope, ultrafast scanning electron microscope and the like gradually emerge, the requirements on a detection system are gradually improved, the existing compact ultrafast electron diffraction device cannot realize quick disassembly and upgrade maintenance, and therefore, a flexible compact hundreds of kilovolts ultrafast electron diffraction device is provided.
Disclosure of Invention
The invention aims to provide a flexible and compact hundred kilovolt ultrafast electron diffraction device to solve the problem that the existing compact ultrafast electron diffraction device proposed in the background art cannot realize quick disassembly and upgrade maintenance.
In order to achieve the above object, a first aspect of the present invention provides a hundred kv ultrafast electron diffraction device, which includes an electron gun body, wherein the electron gun body includes an electron gun chamber, and a dc photocathode electron gun body, a magnetic lens, a sample chamber, a pump light back incident unit, a faraday cylinder chamber, and an imaging device inside the electron gun chamber, a sample displacement stage is fixedly installed on a side surface of the sample chamber, a sample fixing device is fixedly installed inside the sample displacement stage, a titanium sublimation pump, an ion pump, a molecular pump, and a vacuum measurement device are fixedly installed at a bottom of the sample chamber, and a connection line between a cathode center of the dc photocathode electron gun body and a center of an internal space of the sample chamber is a first central axis.
According to the hundred kilovolt ultrafast electron diffraction device of the first aspect of the invention, the bottom surface of the electron gun cavity facing the sample chamber is provided with the first vacuum knife edge, the electron gun body is fixedly installed in the electron gun cavity, the front end and the rear end of the electron gun cavity are both fixedly provided with the first observation window and the second observation window, the center of the first observation window is positioned on the XY plane, the upper end of the electron gun cavity is fixedly provided with the high-voltage electrode, the center of the second observation window and the tail end of the electrode wire of the high-voltage electrode are positioned at the same height, the front panel of the electron gun cavity is fixedly provided with the first knife edge, and the exterior of the electron gun cavity is fixedly provided with six threaded holes.
The hundred kilovolt ultrafast electron diffraction apparatus according to the first aspect of the present invention, wherein the magnetic lens is wound from a copper wire;
preferably, the diameter of the copper wire is 0.5-1.5 mm, preferably 0.8-1.2 mm, and most preferably 1 mm; and/or
Preferably, the magnetic lenses have 30-80 layers in total, and each layer has 10-30 turns; more preferably, the magnetic lenses have 50-60 layers in total, and each layer has 15-25 turns; most preferably, the magnetic lens has a total of 52 layers, 20 turns per layer.
The hundred kilovolt ultrafast electron diffraction device comprises a sample chamber, a magnetic lens, a fixed bi-pass, a gap, a magnetic lens, a magnetic sensor and a control circuit, wherein the sample chamber is of a square six-way structure, is provided with an embedded groove, and is fixedly provided with a main magnetic coil, the front end of the main magnetic coil is fixedly provided with the fixed bi-pass, and the rear end of the main magnetic coil is fixedly provided;
preferably, the depth of the groove is 5-20 mm, more preferably 5-15 mm, and most preferably 10 mm. According to the hundred kilovolt ultrafast electron diffraction device of the first aspect of the invention, a groove is fixedly arranged at the front end of the sample chamber, a third observation window is fixedly arranged at the upper end of the sample chamber, windows are fixedly arranged at the left end, the right end and the upper end of the sample chamber, tangent planes are fixedly arranged at the four corner edges of the upper end of the sample chamber, and a first fixing flange is fixedly arranged at the rear end of the sample chamber;
preferably, the distance between the center of the flange circle of the third observation window and the center of the inner space of the sample chamber is 100-120 mm, more preferably 110-120 mm, and most preferably 119.3 mm. According to the hundred kilovolt ultrafast electron diffraction device of the first aspect of the invention, the inner wall of the pump light back incidence unit is fixedly provided with the reflector, the upper end of the pump light back incidence unit is fixedly provided with the adjusting device, the rear end of the pump light back incidence unit is fixedly provided with the second knife edge, the pump light back incidence unit is a six-way tube, the front side and the rear side of the pump light back incidence unit are fixedly provided with the third fixing flanges, the upper end of the pump light back incidence unit is fixedly provided with the blind flange and the flange observation window, the pump light back incidence unit is connected with the first fixing flange at the rear side of the sample chamber through the third fixing flanges, and the reflector is fixedly arranged on the adjusting device.
According to the hundred kilovolt ultrafast electron diffraction device of the first aspect of the present invention, the outer diameter of the third fixing flange is 150 to 160mm, preferably 150 to 155mm, and most preferably 152 mm; and/or
The reflector has a diameter of 0.5 to 2 inches, preferably 0.5 to 1.5 inches, and most preferably 1 inch.
According to the hundred kilovolt ultrafast electron diffraction device of the first aspect of the present invention, a second knife edge is fixedly formed at the upper end of the blind flange, and the distance between the center of the second knife edge and the center of the blind flange is 20-30 mm, preferably 20-25 mm, and most preferably 23 mm.
The hundred kilovolt ultrafast electron diffraction apparatus according to the first aspect of the present invention, wherein an angle between the reflecting mirror and a horizontal line is 30.7 degrees to 50.4 degrees.
The hundred kilovolt ultrafast electron diffraction device according to the first aspect of the present invention, wherein the first ray path is formed when the angle between the mirror and the horizontal line is 50.4 degrees, the second ray path is formed when the angle between the mirror and the horizontal line is 41.5 degrees, the third ray path is formed when the angle between the mirror and the horizontal line is 30.7 degrees, and the mirror may form the intermediate image (18-1) and the farthest image (18-2).
Compared with the prior art, the invention has the beneficial effects that:
1. according to the flexible compact hundred-kilovolt ultrafast electron diffraction device, the direct-current photocathode electron gun body is adopted, the sample frame is flexible and multifunctional, so that the whole set of device can be used for carrying out various experimental detections, the sample frame can be disassembled and replaced, and some devices needing to be connected between the electron gun body and a sample chamber in series can be connected onto the sample rod, so that the complexity of the system is reduced, and the distance between a cathode and a sample is further shortened;
2. according to the flexible compact hundred-kilovolt ultrafast electron diffraction device, other parts can be connected between the imaging system and the sample chamber through the arrangement of the plurality of imaging positions, so that the flexibility of the device is further improved;
3. this nimble compact hundred kilovolts ultrafast electron diffraction device, through the setting that the sample room also can be connected with other devices, the later stage can be with robotic arm, mass spectrograph, material deposition device, heating device etc. connect collaborative work, increased the flexibility of device.
Drawings
Embodiments of the invention are described in detail below with reference to the attached drawing figures, wherein:
fig. 1 is a perspective view of a multifunctional compact hundreds of kilovolts ultrafast electron diffraction apparatus according to an embodiment of the present invention;
FIG. 2A is a perspective view of an open sample holder, sample rod, BNC interface flange combination in accordance with an embodiment of the present invention;
FIG. 2B is an overall perspective view of an open sample holder according to an embodiment of the present invention; FIG. 2C is a perspective view of an open sample holder compact according to an embodiment of the present invention; FIG. 3 is a perspective view of a compact electron gun chamber according to an embodiment of the present invention;
FIG. 4 is a perspective view of a compact magnetic lens and a magnetic lens mounting bracket according to an embodiment of the invention;
FIG. 5 is a perspective view of a compact multi-functional sample chamber according to an embodiment of the invention;
FIG. 6A is a diagram illustrating the magnetic field distribution simulation result under the compact structural design of the system according to an embodiment of the present invention;
FIG. 6B is a diagram illustrating the results of simulation calculations for convergence of electronic pulses in a compact system configuration according to an embodiment of the present invention;
fig. 7A is a schematic perspective view of a pump light back incident unit according to an embodiment of the invention;
FIG. 7B is a schematic plan two-dimensional view of the working principle of the detachable pump light back-incident unit according to the embodiment of the present invention;
fig. 8 is a connection view of an ultrafast electron diffraction apparatus and other apparatuses according to an embodiment of the present invention.
Description of reference numerals:
1. an electron gun body; 2. an electron gun chamber; 3. a DC photocathode electron gun body; 4. a magnetic lens; 5. a sample chamber; 6. a fixing device; 7. a pump light back incident unit; 8. an adjustment device; 9. a Faraday cage chamber; 10. a displacement table; 11. an imaging device; 12. a molecular pump; 13. an ion pump; 14. a titanium sublimation pump; 15. a vacuum measuring device; 16. a charge measurement chamber; 17. a first laser; 18. a second laser; 1-1, exciting the cathode of the electron gun body; 2-1, a first knife edge; 2-1A, a threaded hole; 2-2A, a first observation window; 2-2B, a second observation window; 2-3, high voltage electrode; 4-1, a main body magnetic coil; 4-2, fixing the two-way pipe; 4-3, a void; 5-1, a groove; 5-2, a third observation window; 5-3, a window; 5-4, cutting; 5-5, a first fixed flange; 6-1, a second fixed flange; 6-2, a sample holder; 6-3, a sample rod; 6-2-1, round concave hole; 6-2-2, groove; 6-2-3, a needle head; 6-2-4, briquetting; 6-2-5, pinhole; 6-2-6, a threaded hole; 7-1, a reflector; 7-2, a second knife edge; 7-3, blind flange; 7-4, a flange observation window; 7-5, a third fixed flange; 17-1, a first ray path; 17-2, a second ray path; 17-3, a third ray path; 18-1, intermediate imaging; 18-2, farthest imaging.
Detailed Description
The invention is further illustrated by the following specific examples, which, however, are to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever.
This section generally describes the materials used in the testing of the present invention, as well as the testing methods. Although many materials and methods of operation are known in the art for the purpose of carrying out the invention, the invention is nevertheless described herein in as detail as possible. It will be apparent to those skilled in the art that the materials and methods of operation used in the present invention are well within the skill of the art, provided that they are not specifically illustrated.
Referring to fig. 1-8, the present invention provides a technical solution: the utility model provides a flexible compact hundred kilovolts ultrafast electron diffraction devices, including electron gun body 1, electron gun body 1 includes electron gun cavity 2 and inside direct current photocathode electron gun body 3, magnetic lens 4, sample room 5, pump light back incidence unit 7, Faraday cylinder cavity 9 and imaging device 11, 5 side fixed mounting in sample room have sample displacement platform 10, the inside fixed sample fixing device 6 that is provided with of sample displacement platform 10, 5 bottom fixed titanium sublimation pump 14 that is provided with in sample room, ion pump 13, molecular pump 12 and vacuum measurement device 15, the line of the negative pole center of direct current photocathode gun body 3 and 5 inner space centers in sample room is first the central axis.
Furthermore, the bottom surface of one side of the electron gun cavity 2 facing the sample chamber 5 is provided with a first vacuum knife edge 2-2A, the magnetic lens 4 is formed by winding a copper wire with the diameter of 1mm, the magnetic lens 4 is totally 52 layers, each layer has 20 turns, the electron gun body 1 is fixedly arranged in the electron gun cavity 2, the front end and the rear end of the electron gun cavity 2 are respectively and fixedly provided with a first observation window 2-2A and a second observation window 2-2B, the center of the first observation window 2-2A is positioned on an XY plane, the upper end of the electron gun cavity 2 is fixedly provided with a high voltage electrode 2-3, the center of the second observation window 2-2B and the tail end of an electrode wire of the high voltage electrode 2-3 are positioned at the same height, the front panel of the electron gun cavity 2 is fixedly provided with a first knife edge 2-1, the outside of the electron gun cavity 2 is fixedly provided with, the effect of observing through a plurality of observation windows is realized, and the use is convenient.
Furthermore, the sample chamber 5 is of a square six-way structure, the sample chamber 5 is provided with an embedded groove 5-1, the depth of the groove 5-1 is 10mm, the magnetic lens 4 is fixedly provided with a main body magnetic coil 4-1, the front end of the main body magnetic coil 4-1 is fixedly provided with a fixed two-way 4-2, and the rear end of the main body magnetic coil 1 is fixedly provided with a gap 4-3, so that the effect that the sample chamber 5 can be connected with other tools through the groove 5-1 is realized, and the connection is convenient.
Furthermore, a groove 5-1 is fixedly formed in the front end of the sample chamber 5, a third observation window 5-2 is fixedly mounted at the upper end of the sample chamber 5, windows 5-3 are fixedly formed in the left end, the right end and the upper end of the sample chamber 5, tangent planes 5-4 are fixedly arranged at four corners of the upper end of the sample chamber 5, a first fixing flange 5-5 is fixedly mounted at the rear end of the sample chamber 5, the distance between the center of a flange circle of the third observation window 5-2 and the center of an inner space of the sample chamber 5 is 119.3mm, and the sample chamber 5 is easily connected with other objects due to the arrangement of the flanges.
Further, a reflector 7-1 is fixedly arranged on the inner wall of the pump light back incidence unit 7, an adjusting device 8 is fixedly arranged at the upper end of the pump light back incidence unit 7, a second knife edge 7-2 is fixedly arranged at the rear end of the pump light back incidence unit 7, the pump light back incidence unit 7 is a six-way tube, third fixing flanges 7-5 are fixedly arranged at the front side and the rear side of the pump light back incidence unit 7, the outer diameter of each third fixing flange is 152mm, a blind flange 7-3 and a flange observation window 7-4 are fixedly arranged at the upper end of the pump light back incidence unit 7, the pump light back incidence unit 7 is connected with the first fixing flange 5-5 at the rear side of the sample chamber 5 through the third fixing flanges 7-5, the diameter of the reflector 7-1 is one inch, and the reflector 7-1 is fixedly arranged on the adjusting device 8, so that the effect of easy installation of the pump light back incidence unit 7 is realized, the assembly is convenient.
Further, a second knife edge 7-2 is fixedly arranged at the upper end of the blind flange 7-3, the distance between the circle center of the second knife edge 7-2 and the circle center of the 7-3 is 23mm, a first light path is formed when the included angle between the reflector 7 and the horizontal line is 41.5 degrees and is 17-2, a second light path is formed when the included angle between the reflector 7 and the horizontal line is 50.4 degrees and is 17-1, a third light path is formed when the included angle between the reflector 7 and the horizontal line is 30.7 degrees and is 17-3, and the reflector 7-1 can form a middle imaging 18-1 and a farthest imaging 18-2, so that the imaging can be conveniently confirmed, and the use is convenient.
The working principle is as follows: firstly, cleaning a sample by using acetone, alcohol and distilled water, and then fixing the sample on a sample fixing device 6, wherein the sample fixing device comprises a fixing flange 6-1, a sample frame 6-2 and a sample rod 6-3, if a transmission diffraction experiment is carried out, the sample can grow on a carrier net and then is placed on the sample frame 6-2, the sample frame 6-2 consists of five repeated units, and each unit comprises a circular concave hole 6-2-1 and a groove 6-2-2, 6-2-3 of pinhole, 6-2-4 of briquetting, round concave hole 6-2-1 with threaded hole 6-2-5 on both sides, 6-2-3 of pinhole with threaded hole 6-2-6 on both sides, put the carrier net with sample growth on the round concave hole 6-2-1 bottom, then press briquetting 6-2-4 into concave hole 6-2-1, fix with bolt through threaded hole 6-2-5, there is a through hole 6-2-4A in the center of briquetting, probe electronic pulse and pump laser enter from this during the experiment, the top of the cylinder at the bottom of the briquetting has a sharp annular knife edge projection 6-2-4B with diameter of 1.5mm, the projection can be made by bonding thin wire with diameter of 0.2mm, also can use lathe to process annular knife edge with diameter of 0.2mm, the bulge can effectively prevent the sample from deforming caused by the pressure stress of a cylinder at the bottom of the pressing block on the sample, the groove 6-2-2 at the side surface of the sample frame is of an open design and is used for possible experimental modification, such as increasing a needle point, a temperature changing device, a stripe camera and the like, so as to realize more functions, the pinhole 6-2-3 on the sample frame is also of an open design and is used for installing a metal needle point, a position mark and the like, so as to increase the experimental functions and the convenience of adjustment, if an ultrafast electronic surface diffraction experiment is carried out, the sample can be fixed on the surface of the sample frame through the assistance of the groove 6-2-2, the threaded hole 6-2-6 or the pinhole 6-2-3 and the like, if electronic shadow imaging is carried out, the sample can be fixed on one side or the bottom of the sample, if schlieren imaging is carried out, a schlieren device (carrying net) can be fixed at the front side of the sample holder by utilizing the groove 6-2-2, the threaded hole 6-2-6 or the pinhole 6-2-3, the sample holder 6-2 and the sample rod 6-3 are fixed through bolts, and the sample rod 6-3 is connected with the flange 6-1. The top of the flange 6-1 is provided with 4 BNC connectors 6-1A, which are also of open design. If a device (such as a stripe camera, a temperature raising and reducing device and the like) is arranged on the sample rack, the device can be connected with the outside through a vacuum lead and a connector 6-1A, the function of the sample rack is expanded, then the flange 6-1, the sample rack 6-2 and the sample rod 6-3 are connected and then fixed on the sample displacement platform 3, and the sample displacement platform is fixed on the left side surface of the sample chamber 5. The feeding of the sample, the adjustment of the position angle and the like can be realized through the sample displacement table, the 4-dimensional adjustment, the XYZ translation and the rotation around the axis of the sample rod 6-3 can be realized, the sample frame 6-2 can be disassembled and is changed to other sample rods, the adjustment of more dimensions of the sample position can be realized, then, the whole sample chamber 5 is vacuumized, and the mechanical pump system is started firstlyThe cavity body is pumped, the mechanical pump can adopt a roots pump or other primary pumps, the pumping hole is connected with the molecular pump 12 when the mechanical pump works, the vacuum condition of the system is measured in real time through a vacuum measuring device 15 (such as an ion gauge), and the vacuum degree of the system is lower than 2 x 10-2When Torr is used, the molecular pump 12 is turned on, and after about ten hours, the vacuum degree is 2 x 10-8On the left and right sides, the ion pump 13 is started, the vacuum degree is reduced to 10 after continuously waiting for more than ten hours-9Torr, intermittently starting the titanium sublimation pump 14 to maintain the vacuum degree of the whole system at 10-10Torr magnitude, at the moment, ultrafast electron diffraction related experiments can be carried out, ultrafast electron diffraction technology needs to utilize a light splitting device to split laser pulse into two beams, one beam (a second laser 18) is used for exciting a cathode 1-1 of an electron gun body to generate probe electrons, the other beam (a first laser 17) pumps a reaction region, the probe electrons are detected in the reaction region in advance or delayed by controlling the optical path difference of the two beams of lasers, time resolution measurement is further realized, the second laser 18 with 266nm is used for exciting the cathode of the electron gun body, a direct current photocathode electron gun body 1 is excited by the second laser 18 to generate probe electron pulses, the probe electron pulses are accelerated to 100keV magnitude in the electron gun body, the design of the direct current photocathode electron gun body 1 is optimized through electric field simulation, the maximum electric field on the cathode surface of the direct current photocathode electron gun body is not more than 12kV/mm, the maximum electric field on the anode surface is not, an electron gun body 1 is fixed in an electron gun chamber 2, the electron gun chamber 2 is provided with two observation windows 2-2A and 2-2B for assisting the installation of the electron gun body and observing the working condition of the electron gun body, the center of 2-2A is positioned on an XY plane and is used for observing the working conditions of a cathode and an anode, the center of 2-2B is positioned at the same height with the tail end of an electrode wire of a high-voltage electrode 2-3 and is used for observing the installation of the cathode and an auxiliary high-voltage electrode 2-3, a front panel of the electron gun chamber 2 is provided with a first knife edge 2-1, six threaded holes 2-1A are arranged outside the electron gun chamber 2 and are used for connecting and fixing with other devices, generated electron pulses leave the cathode 1-1 of the electron gun body and the chamber 2 thereof and then enter a magnetic lens device 4 and are focused by the magnetic lens device 4, the magnetic lens device 4 consists of a main magnetic coil 4-, the electron pulse enters the sample chamber 5 via the internal channel of the two-way 4-2, during which it is generated by the main magnetic coil 4-1Magnetic field convergence, pumping laser is required to be incident on a sample during experiment to excite the sample, the sample chamber 5 is provided with a plurality of observation windows to observe the interior of the sample chamber and can also be used as a pumping laser incidence window, an electronic pulse penetrates through the central through hole 6-2-4A of the sample holder pressing block and then penetrates through the sample excited by the pumping light after entering the central position of the interior of the sample chamber 5 to generate diffraction, a diffraction pattern is collected by the imaging system 11, and finally the formed image is input into a computer, as mentioned above, the sample can also be arranged at the positions of the sample holder pin hole 6-2-3 and the groove 6-2-2, and the like, at the moment, the probe electronic pulse does not pass through the central through hole 6-2-4B of the sample holder pressing block but acts on the sample through other paths and then is collected by the imaging system 11, the internal charge quantity and charge distribution of the electronic pulse are measured by a charge measuring unit, and the charge measuring unit comprises a Faraday cylinder 9, a charge measuring chamber 16 and a displacement table 10. The charge measurement chamber 16 is a three-way chamber, the Faraday cup 9 is arranged inside the charge measurement chamber 16, the spatial position is adjusted by an external displacement platform 10, and the unit can be arranged behind the sample chamber 5 or behind the rear incidence chamber 7 according to requirements during operation.
Compact detachable construction: because the electron space repulsive force exists, the electron beam can be greatly widened in the process of drifting to a sample, the time resolution capability of the electron beam is obviously reduced, the distance between the cathode of the electron gun body and the sample needs to be shortened, for the consideration of practical and economic factors, the later upgrade along with the development of a laboratory is considered, the device is designed in a compact mode on the basis of flexible and detachable mode, a main body magnetic coil 4-1 and a fixed two-way 4-2 of a magnetic lens 4 are specially designed, the configuration of the main body magnetic coil 4-1 is designed according to electromagnetic fields and particle simulation results under the consideration of the compact requirement, the device is formed by winding copper wires with the diameter of 1mm, the total number of 52 layers is obtained, each layer has 20 turns, the diameter of flanges at two ends of the two-way tube 4-2 is 70mm, the thickness of the flanges at two sides is reduced to be 10mm thick, a gap 4-3 between flanges of a main magnetic coil 4-1 and a main magnetic coil 4-2 is slightly larger than the thickness of an M6 nut, so that a solid wrench can enter the gap to complete nut installation, a sample chamber 5 is provided with an embedded groove 5-1, the depth is 10mm, during installation, specially-made bolts are inserted into 6 threaded holes 5-1A in the groove 5-1, a flange at one end 4-2 is sunk into the groove 5-1, the nut is placed into the gap 4-3, the flange is sunk while the nut is screwed, the fixation is completed by repeated operation, the other end 4-2 is connected with an electron gun chamber 2, the bolts are inserted into 6 threaded holes 2-1A outside a first knife edge 2-1, the flange at the other end 4-2 is correspondingly installed, the nut is placed into the gap 4-3 at the other end to complete fixation, the design reduces the shortest distance between the cathode of the electron gun body and a sample to 140mm under the condition of the existence of the magnetic lens; if the magnetic lens is not installed, the length of the fixed bi-pass 4-2 can be further shortened, the shortest distance between the cathode of the electron gun body and the sample can be further reduced to about 100mm, the distribution of the magnetic field of the magnetic coil 4-1 along the central line of the magnetic lens 4 is shown as a dotted line in fig. 6A, and the magnetic field cannot penetrate into the electron gun body due to the existence of the magnetic shielding of the electron gun body; the magnetic field without magnetic shielding is shown by the solid line in fig. 6A, and the zero point in the figure is the surface of the cathode 1-1 of the dc photocathode electron gun body 1.
Flexible imaging system: the position of the imaging system 11 is variable, with a certain flexibility, and it can be mounted directly on the first fixed flange 5-5 behind the sample chamber 5, which flange is 263mm away from the cathode surface of the dc photocathode electron gun body 1, which can be called the closest imaging position of the imaging system; the imaging system 11 can also be mounted on the rear flange of the rear incident chamber 7 at a position 437mm from the cathode surface of the dc photocathode electron gun body 1, which can be referred to as an intermediate imaging position; the imaging system may also be mounted on the rear flange of the charge measurement unit chamber 16 at a position 657mm from the cathode surface of the dc photocathode electron gun body 1, which may be referred to as the farthest imaging position, where the imaging system 11 shown in fig. 1 is located. The rear incident chamber 7 and the charge measurement chamber 16 can be flexibly installed or removed according to experimental needs, the magnetic field convergence effect is plotted in fig. 6B, fig. 6B shows the change of the diameter of the electron pulse along with the movement distance, and the zero point in the diagram is the cathode surface of the direct current photocathode electron gun body 1. When the current applied by the magnetic lens 4 is 3.5A, the electronic pulse is converged at the central position of the internal space of the sample chamber 5, which corresponds to the 'convergence at sample' curve in FIG. 6B; at a current of 2.8A, the electron pulse converges at the nearest imaging position, corresponding to the "nearest imaging convergence" curve in fig. 6B; at a current of 2.56A, the electron pulse converges at the intermediate imaging position, corresponding to the "intermediate imaging convergence" curve in fig. 6B; at a current of 2.46A, the electron pulse converges at the farthest imaging position, which corresponds to the "farthest imaging convergence" curve in fig. 6B; when the current applied to the magnetic lens 4 is 0A, no magnetic field is generated, and no electron pulse convergence occurs, which corresponds to the "no convergence" curve in fig. 6B.
Various pump laser incidence schemes: when the experiment is carried out, the first pumping laser 17 needs to be incident on the sample to excite the sample, and the device has multiple incidence modes and increases the experiment flexibility as much as possible. The sample chamber 5 is provided with a plurality of observation windows which can realize the internal observation of the sample chamber and can also be used as an incident window for pumping the first laser 17, the third observation window 5-2 is a specially designed window, the diameter specification of a flange is 34mm, the sample chamber 5 is a cube six-way, 8 cube corners of the cube are cut off, a leakage section 5-4 is formed, two third observation windows 5-2 are symmetrically arranged on two oblique planes on the upper side at the rear part 5-4, the vertical distance between the bottom surface of the flange of the third observation window 5-2 and the oblique plane 5-3 for mounting is 38.5mm, the distance is the nearest distance which can ensure the normal nut mounting of the third observation window 5-2 and does not interfere with other flanges of the cavity, the distance between the center of the flange circle of the third observation window 5-2 and the center of the internal space of the sample chamber is 119.3mm, the observation range of the center of the internal space of the sample chamber can reach about plus or minus 20, pump laser can be obliquely incident into the sample chamber from top to bottom through a third observation window 5-2 to excite the sample, incident light can also be incident from the top and the side of the sample chamber through 3 flange windows 5-3 with the diameter of 152mm in the left and right directions of the sample chamber and above, FIG. 7A shows the composition of a rear incident unit part, wherein in order to show the internal structure, a chamber 7 is cut along a YZ plane and a part of the display is removed, the rear incident unit mainly comprises a rear incident chamber 7, a reflector 7-1, an adjusting device 8 and other parts, the rear incident chamber 7 is a six-way, the outer diameters of third fixed flanges 7-5 at the front side and the rear side of the six-way are 152mm, the pipelines corresponding to the two flanges are a main chamber, the diameter of an upper flange in the middle of the six-way is 114mm, a blind flange 7-3 is installed on the main chamber, the lower flange is 70mm, and the, a flange observation window 7-4 is arranged on the cavity, the cavity is connected with a first fixed flange 5-5 at the rear side of the sample chamber through a third fixed flange 7-5 at the front side of the cavity, the diameter of a reflector 7-1 is one inch, the cavity is fixed on an adjusting device 8, a blind flange 7-3 is provided with a second knife edge 7-2, the circle center of the second knife edge 7-2 is 7-3 and 23mm away from the circle center, the second knife edge 7-2 can be used for installing a flange with the diameter of 35mm, the adjusting device 8 is fixed on the second knife edge 7-2 through a flange with the diameter of 35mm, then the blind flange 7-3 and the second knife edge are fixed on a flange with the diameter of 114mm at the top of the cavity 7 together, a first pumping laser 17 enters the cavity 7 through the flange observation window 7-4 and is reflected by an internal reflector 7-1 and enters the, realizing back incidence, fig. 7B shows a projection principle diagram of an incident path of the pump light 17 on an XY plane, a center of a reflector 7-1 and a center of an internal space of the sample chamber 5 are on the same horizontal plane, a distance between two points is L1 being 196mm, and L2 being 23mm, when an included angle between the reflector 7 and a horizontal line is 41.5 degrees, a second light path is 17-2, at this time, the light is incident to the center of the sample chamber 5, when the included angle is 50.4 degrees, a first light path is 17-1, at this time, the light is incident to an edge of the sample chamber, when the included angle is 30.7 degrees, a third light path is 17-3, at this time, the light is incident to the other edge of the sample chamber 5, the light at both paths 17-1 and 17-3 will be blocked by a chamber wall, the light cannot normally enter, thus ensuring that a reflector adjustment range of the normal incidence of the pump light 17 is 30.7 degrees to 50.4 degrees, radius range lines of the probe electronic pulse during middle imaging and farthest imaging are marked 18-1 and 18-2, and the electronic pulse imaging cannot be interfered when the reflector 7 is adjusted within the range of 30.7-50.4 degrees, so that the pumping light can be incident in the directions of upper, left and right, rear, upper oblique side and the like to form multi-angle incidence.
Upgrading and modifying the device: later along with the development of the laboratory, other devices can be connected between the electron gun chamber 2 and the sample chamber 5 for upgrading, such as an RF electron pulse compression cavity, a multi-path magnetic lens, a magnetic deflection lens, a stripe camera, a movable reflector and the like, and meanwhile, the device can be connected with other devices through a window 5-3 of the sample chamber, such as a mass spectrometer, a sample heating device, a material growing device, an Auger electron spectrometer, a scanning tunneling microscope, a scanning electron microscope, other surface probes and the like, FIG. 8 shows a combined working schematic diagram connected with the material growing device (MBE) through the window 5-3, because only the schematic diagram is shown, relevant parts are simplified and processed, an upgraded ultrafast electron diffraction device is arranged in a dotted line box, a rear incidence unit and a charge measuring unit can be installed or disassembled according to the experiment, the whole device is very flexible and has huge functions, and compact, table-top size.
Although the present invention has been described to a certain extent, it is apparent that appropriate changes in the respective conditions may be made without departing from the spirit and scope of the present invention. It is to be understood that the invention is not limited to the described embodiments, but is to be accorded the scope consistent with the claims, including equivalents of each element described.
Claims (10)
1. The utility model provides a hundred kilovolts ultrafast electron diffraction devices, includes the electron gun body, its characterized in that, the electron gun body includes electron gun cavity and inside direct current photocathode electron gun body, magnetic lens, sample room, pump light back of the body incident unit, Faraday cylinder cavity and imaging device, sample room side fixed mounting has sample displacement platform, the inside fixed sample fixing device that is provided with of sample displacement platform, the fixed titanium sublimation pump, ion pump, molecular pump and the vacuum measurement device that is provided with in sample room bottom, the line at the negative pole center of direct current photocathode gun body and sample room inner space center is first the central axis.
2. The hundred kilovolt ultrafast electron diffraction device of claim 1, wherein a bottom surface of a side of the electron gun chamber facing the sample chamber is provided with a first vacuum knife edge, the electron gun body is fixedly installed in the electron gun chamber, a first observation window and a second observation window are fixedly formed at both front and rear ends of the electron gun chamber, a center of the first observation window is located on an XY plane, a high voltage electrode is fixedly installed at an upper end of the electron gun chamber, a center of the second observation window and a tail end of an electrode wire of the high voltage electrode are located at the same height, a first knife edge is fixedly formed on a front panel of the electron gun chamber, and six threaded holes are fixedly formed outside the electron gun chamber.
3. The hundred kilovolt ultrafast electron diffraction device of claim 1 or 2, wherein the magnetic lens is wound from a copper wire;
preferably, the diameter of the copper wire is 0.5-1.5 mm, preferably 0.8-1.2 mm, and most preferably 1 mm; and/or
Preferably, the magnetic lenses have 30-80 layers in total, and each layer has 10-30 turns; more preferably, the magnetic lenses have 50-60 layers in total, and each layer has 15-25 turns; most preferably, the magnetic lens has a total of 52 layers, 20 turns per layer.
4. The hundred kilovolt ultrafast electron diffraction device according to any one of claims 1 to 3, wherein the sample chamber has a square six-way structure, the sample chamber has an embedded groove, a main body magnetic coil is fixedly arranged on the magnetic lens, a fixed two-way is fixedly arranged at the front end of the main body magnetic coil, and a gap is fixedly arranged at the rear end of the main body magnetic coil;
preferably, the depth of the groove is 5-20 mm, more preferably 5-15 mm, and most preferably 10 mm.
5. The hundred kilovolt ultrafast electron diffraction device according to any one of claims 1 to 4, wherein a groove is fixedly formed at the front end of the sample chamber, a third observation window is fixedly installed at the upper end of the sample chamber, windows are fixedly formed at the left end, the right end and the upper end of the sample chamber, cutting planes are fixedly arranged at four corner edges of the upper end of the sample chamber, and a first fixing flange is fixedly installed at the rear end of the sample chamber;
preferably, the distance between the center of the flange circle of the third observation window and the center of the inner space of the sample chamber is 100-120 mm, more preferably 110-120 mm, and most preferably 119.3 mm.
6. The hundred kilovolt ultrafast electron diffraction device according to any one of claims 1 to 5, wherein a reflector is fixedly disposed on an inner wall of the pump light back incident unit, an adjusting device is fixedly mounted on an upper end of the pump light back incident unit, a second knife edge is fixedly disposed at a rear end of the pump light back incident unit, the pump light back incident unit is a six-pass tube, third fixing flanges are fixedly mounted on front and rear sides of the pump light back incident unit, a blind flange and a flange observation window are fixedly mounted on an upper end of the pump light back incident unit, the pump light back incident unit is connected with the first fixing flange on the rear side of the sample chamber through the third fixing flanges, and the reflector is fixedly mounted on the adjusting device.
7. The hundred kilovolt ultrafast electron diffraction device of claim 6, wherein the third fixing flange has an outer diameter of 150-160 mm, preferably 150-155 mm, and most preferably 152 mm; and/or
The reflector has a diameter of 0.5 to 2 inches, preferably 0.5 to 1.5 inches, and most preferably 1 inch.
8. The hundred kilovolt ultrafast electron diffraction device according to claim 6 or 7, wherein a second knife edge is fixedly formed at the upper end of the blind flange, and the distance between the center of the second knife edge and the center of the blind flange is 20-30 mm, preferably 20-25 mm, and most preferably 23 mm.
9. The hundred kilovolt ultrafast electron diffraction apparatus of any one of claims 6 to 8, wherein the angle between the reflecting mirror and the horizontal line is 30.7 degrees to 50.4 degrees.
10. The hundred kilovolt ultrafast electron diffraction device of claim 9, wherein the mirror forms a first ray path when the mirror is at an angle of 50.4 degrees to the horizontal, a second ray path when the mirror is at an angle of 41.5 degrees to the horizontal, and a third ray path when the mirror is at an angle of 30.7 degrees to the horizontal, the mirrors forming the intermediate (18-1) and farthest (18-2) images.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011281330.4A CN112485276A (en) | 2020-11-16 | 2020-11-16 | Hundred kilovolt ultrafast electron diffraction device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011281330.4A CN112485276A (en) | 2020-11-16 | 2020-11-16 | Hundred kilovolt ultrafast electron diffraction device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112485276A true CN112485276A (en) | 2021-03-12 |
Family
ID=74931301
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011281330.4A Pending CN112485276A (en) | 2020-11-16 | 2020-11-16 | Hundred kilovolt ultrafast electron diffraction device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112485276A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113203761A (en) * | 2021-04-21 | 2021-08-03 | 华中科技大学 | Time resolution sample inspection device with multiple working modes |
| CN114384103A (en) * | 2021-12-08 | 2022-04-22 | 费勉仪器科技（上海）有限公司 | Switchable vacuum optical assembly and vacuum light source system |
| CN115424912A (en) * | 2022-09-15 | 2022-12-02 | 中国科学院物理研究所 | Ultrafast scanning electron microscope system and using method thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1851843A (en) * | 2005-04-22 | 2006-10-25 | 中国科学院物理研究所 | Electron beam generating and controlling device |
| CN102592929A (en) * | 2011-01-18 | 2012-07-18 | 华东师范大学 | Electron gun device for generating high-brightness femtosecond electronic pulse |
| CN102751399A (en) * | 2012-07-17 | 2012-10-24 | 大连理工常州研究院有限公司 | Facility for manufacturing vertical GaN-based LED chips by metal substrates |
| CN102830095A (en) * | 2011-06-14 | 2012-12-19 | 华东师范大学 | Molecular four-dimensional imaging system |
| CN106645236A (en) * | 2016-10-20 | 2017-05-10 | 中国科学院物理研究所 | Ultra-fast transmission electron microscope system and use method thereof |
-
2020
- 2020-11-16 CN CN202011281330.4A patent/CN112485276A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1851843A (en) * | 2005-04-22 | 2006-10-25 | 中国科学院物理研究所 | Electron beam generating and controlling device |
| CN102592929A (en) * | 2011-01-18 | 2012-07-18 | 华东师范大学 | Electron gun device for generating high-brightness femtosecond electronic pulse |
| CN102830095A (en) * | 2011-06-14 | 2012-12-19 | 华东师范大学 | Molecular four-dimensional imaging system |
| CN102751399A (en) * | 2012-07-17 | 2012-10-24 | 大连理工常州研究院有限公司 | Facility for manufacturing vertical GaN-based LED chips by metal substrates |
| CN106645236A (en) * | 2016-10-20 | 2017-05-10 | 中国科学院物理研究所 | Ultra-fast transmission electron microscope system and use method thereof |
Non-Patent Citations (1)
| Title |
|---|
| 李梦超: "百千伏超快电子衍射系统的研发", 《中国博士学位论文全文数据库基础科学辑》 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113203761A (en) * | 2021-04-21 | 2021-08-03 | 华中科技大学 | Time resolution sample inspection device with multiple working modes |
| CN113203761B (en) * | 2021-04-21 | 2022-04-01 | 华中科技大学 | Time resolution sample inspection device with multiple working modes |
| CN114384103A (en) * | 2021-12-08 | 2022-04-22 | 费勉仪器科技（上海）有限公司 | Switchable vacuum optical assembly and vacuum light source system |
| CN115424912A (en) * | 2022-09-15 | 2022-12-02 | 中国科学院物理研究所 | Ultrafast scanning electron microscope system and using method thereof |
| CN115424912B (en) * | 2022-09-15 | 2024-06-07 | 中国科学院物理研究所 | Ultrafast scanning electron microscope system and application method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112485276A (en) | Hundred kilovolt ultrafast electron diffraction device | |
| US9048060B2 (en) | Beam pulsing device for use in charged-particle microscopy | |
| US20100116985A1 (en) | Laser atom probe methods | |
| CN104330430B (en) | Apparatus for evaluating photoelectron emissivity of photocathode material, and evaluation method thereof | |
| CN104134604A (en) | Launching performance evaluation device and evaluation method for electron beam of field emission electron source | |
| EP0641011A2 (en) | An electron beam apparatus | |
| US11694870B2 (en) | Stage apparatus | |
| WO2005104307A2 (en) | Laser atom probes | |
| JP6727193B2 (en) | High voltage feedthrough assembly, electron diffraction or imaging device, and method of operating an electrode device in a vacuum environment | |
| CN111326380B (en) | Direct current ultrafast electron gun of composite focusing grid-carrying photocathode | |
| WO2015015957A1 (en) | Charged particle beam apparatus | |
| CN108398712B (en) | Conical strip crystal spectrometer and installation and adjustment method thereof | |
| US9263229B2 (en) | Device and method for electron emission and device including such an electron emission system | |
| CN102651300B (en) | Two-dimensional array type plasma parameter detecting device | |
| CN111063599B (en) | Ion implantation device | |
| GB963832A (en) | Electron beam welding | |
| US4562352A (en) | Analyzing apparatus capable of analyzing a surface at a high resolution | |
| Harp et al. | Electron beam probing of plasmas | |
| WO2020046892A1 (en) | Molecular imaging of biological samples with sub-cellular spatial resolution and high sensitivity | |
| GB1597841A (en) | Electron beam focussing | |
| JP3085390B2 (en) | Charged beam local processing equipment | |
| US3508049A (en) | Corpuscular-ray microscope with an objective lens which also forms a condenser-lens field | |
| Haimson | X-ray source without moving parts for ultra-high speed tomography | |
| JP3494152B2 (en) | Scanning electron microscope | |
| CN115424912B (en) | Ultrafast scanning electron microscope system and application method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20210312 |
|
| RJ01 | Rejection of invention patent application after publication |