IL305432B2 - Vacuum tube methods - Google Patents

Description

ASI10 VACUUM TUBE TECHNIQUES FIELD OF THE INVENTION id="p-1" id="p-1" id="p-1"

[0001] Some applications of the present invention relate in general to vacuum tubes. More specifically, some applications of the present invention relate to the manufacture of vacuum tubes for gyrotrons.

BACKGROUND id="p-2" id="p-2" id="p-2"

[0002] Gyrotrons are a category of high-powered vacuum tube devices that generate millimeter-wave electromagnetic waves by the cyclotron resonance of electrons in a strong electromagnetic field. They were first proposed theoretically in the 1960s and have since been developed significantly for various implementations. id="p-3" id="p-3" id="p-3"

[0003] Operating at frequencies from about 20 GHz to 250 GHz or more, they are particularly valuable for their ability to produce high levels of power, which is critical in a variety of scientific and technological contexts. The peak power for short pulses (microseconds) can be as high as a few megawatts and average power can reach hundreds of kilowatts. id="p-4" id="p-4" id="p-4"

[0004] The most prominent implementation of gyrotrons is in nuclear fusion research, where they are used to heat the plasma in electromagnetic confinement fusion reactors. In these systems, the millimeter-wave energy from the gyrotron is used to heat the ions to the point where fusion can occur. Other implementations for gyrotrons include industrial heating, material processing, radar systems, communication, and cancer treatment.

SUMMARY OF THE INVENTION id="p-5" id="p-5" id="p-5"

[0005] This summary is meant to provide some examples and is not intended to be limiting of the scope of the invention in any way. For example, any feature included in an example of this summary is not ASI10 required by the claims, unless the claims explicitly recite the features. Also, the features, components, steps, concepts, etc. described in examples in this summary and elsewhere in this disclosure can be combined in a variety of ways. Various features and steps as described elsewhere in this disclosure may be included in the examples summarized here. id="p-6" id="p-6" id="p-6"

[0006] Gyrotrons comprise, inter alia, a vacuum tube and an electromagnetic coil (solenoid). An electron gun at one end of the vacuum tube (e.g. in an electron gun chamber) emits a beam of electrons that travels through a tubular resonant cavity situated within the electromagnetic coil. The electromagnetic coil provides a strong axial electromagnetic field that causes the electrons to move helically through the resonant cavity. Within the resonant cavity (e.g. where the electromagnetic field is at its maximum), the electrons radiate electromagnetic waves along the axis of the resonant cavity. The spent electrons are absorbed by a collector at the opposite end of the resonant cavity from the electron gun. The millimeter-wave radiation radiated by the electrons is formed into a beam that is converted by a mode converter and directed out of the vacuum tube (e.g. via a vacuum-tight window) for use. id="p-7" id="p-7" id="p-7"

[0007] Existing techniques for manufacturing gyrotron componentry result in a gap, surrounding the resonant cavity, between the resonant cavity and the coil. A larger gap requires a higher-powered coil, such as a cryogenically-cooled superconductive coil. Existing techniques include passing the coil over the electron gun or collector after the vacuum tube has been assembled, hermetically sealed, and evacuated. This places limitations on the size of the electron gun and/or collector – i.e. there is a trade-off between reducing the inner diameter of the coil and increasing the size of the electron gun and/or collector. id="p-8" id="p-8" id="p-8"

[0008] Disclosed herein are manufacturing techniques for gyrotron componentry having a decreased gap between the resonance chamber and ASI10 coil, by providing independence between the inner diameter of the coil and the size of the electron gun (e.g. the electron gun chamber) and/or the collector (e.g. the collector chamber). id="p-9" id="p-9" id="p-9"

[0009] For some implementations, the coil is placed around the resonance chamber prior to connecting the electron gun chamber and/or the collector chamber to the resonance chamber. For some such implementations, this is facilitated by the identification, by the inventors, that effective evacuation of the vacuum tube is achievable without baking the resonant cavity – e.g. by selectively heating the chambers. This allows evacuation (which requires the vacuum tube to be assembled and hermetically sealed) to be performed after placement of the coil around the resonance chamber, without heat damage to the coil. id="p-10" id="p-10" id="p-10"

[0010] There is therefore provided, in accordance with some implementations, a method including assembling gyrotron componentry that includes a vacuum tube and/or an electromagnetic coil. The vacuum tube may include a resonance cavity, an electron gun chamber, and/or a collector chamber. The electromagnet coil may be disposed externally around the resonance cavity. id="p-11" id="p-11" id="p-11"

[0011] The vacuum tube may be defined at least in part by a tubular component. The electron gun chamber may be hermetically sealed to a gun end of the tubular component such that an interior of the electron gun chamber is continuous with an interior of the resonance cavity, The collector chamber may be hermetically sealed to a collector end of the tubular component such that an interior of the collector chamber is continuous with the interior of the resonance cavity. id="p-12" id="p-12" id="p-12"

[0012] The method may include evacuating the vacuum tube subsequently to assembling the gyrotron componentry by applying a vacuum to the vacuum tube, and/or baking the vacuum tube by selectively heating the electron gun chamber and the collector chamber. id="p-13" id="p-13" id="p-13"

[0013] For some implementations, the electromagnet coil is not superconducting, and assembling the gyrotron componentry includes ASI10 assembling the gyrotron componentry that includes the electromagnetic coil that is not superconducting. id="p-14" id="p-14" id="p-14"

[0014] For some implementations, baking the vacuum tube includes baking the vacuum tube while applying the vacuum to the vacuum tube. id="p-15" id="p-15" id="p-15"

[0015] For some implementations, applying the vacuum to the vacuum tube includes applying the vacuum via a port on the electron gun chamber. id="p-16" id="p-16" id="p-16"

[0016] For some implementations, applying the vacuum to the vacuum tube includes applying the vacuum via a port on the collector chamber. id="p-17" id="p-17" id="p-17"

[0017] For some implementations, applying the vacuum to the vacuum tube includes applying the vacuum via a first port on the electron gun chamber and a second port on the collector chamber. id="p-18" id="p-18" id="p-18"

[0018] For some implementations, assembling the gyrotron componentry includes forming the electromagnetic coil by winding onto the tubular component. id="p-19" id="p-19" id="p-19"

[0019] For some implementations, assembling the gyrotron componentry includes sliding the electromagnetic coil onto the tubular component. id="p-20" id="p-20" id="p-20"

[0020] For some implementations, selectively heating the electron gun chamber and the collector chamber includes heating the electron gun chamber and the collector chamber using at least one heating mantle. id="p-21" id="p-21" id="p-21"

[0021] For some implementations, selectively heating the electron gun chamber and the collector chamber includes applying cooling to the resonance cavity. id="p-22" id="p-22" id="p-22"

[0022] For some implementations: the resonance cavity includes further includes a conductive liner, and/or assembling the gyrotron componentry includes inserting the conductive liner into the tubular component.

ASI10 id="p-23" id="p-23" id="p-23"

[0023] For some implementations, the gyrotron componentry is componentry of a continuous-wave gyrotron. id="p-24" id="p-24" id="p-24"

[0024] For some implementations, the method further includes utilizing the gyrotron componentry in a gyrotron. id="p-25" id="p-25" id="p-25"

[0025] For some implementations, the method further includes assembling a gyrotron that includes the gyrotron componentry. id="p-26" id="p-26" id="p-26"

[0026] For some implementations, applying the vacuum includes applying the vacuum at the electron gun chamber. id="p-27" id="p-27" id="p-27"

[0027] For some implementations, applying the vacuum includes applying the vacuum both at the electron gun chamber and at the collector chamber. id="p-28" id="p-28" id="p-28"

[0028] For some implementations, applying the vacuum includes applying the vacuum both (i) via a first vacuum port at the electron gun chamber, and (ii) via a second vacuum port at the collector chamber. id="p-29" id="p-29" id="p-29"

[0029] For some implementations, applying the vacuum includes applying the vacuum both (i) via a first vacuum pump connected to the electron gun chamber, and (ii) via a second vacuum pump connected to the collector chamber. id="p-30" id="p-30" id="p-30"

[0030] For some implementations, selectively heating the electron gun chamber and the collector chamber includes selectively heating the electron gun chamber and the collector chamber to a temperature of at least 250 degrees C. id="p-31" id="p-31" id="p-31"

[0031] For some implementations, the temperature is at least 3degrees C, and heating the electron gun chamber and the collector chamber to the temperature includes heating the electron gun chamber and the collector chamber to the temperature of at least 350 degrees C. id="p-32" id="p-32" id="p-32"

[0032] For some implementations, heating the electron gun chamber and the collector chamber includes heating the electron gun chamber ASI10 and the collector chamber while a temperature of the tubular component does not exceed 80 degrees C. id="p-33" id="p-33" id="p-33"

[0033] For some implementations, baking the vacuum tube includes holding the electron gun chamber and the collector chamber at the temperature for at least 1 day. id="p-34" id="p-34" id="p-34"

[0034] For some implementations, holding the electron gun chamber and the collector chamber at the temperature for at least 1 day includes holding the electron gun chamber and the collector chamber at the temperature for at least 2 days. id="p-35" id="p-35" id="p-35"

[0035] For some implementations, assembling the gyrotron componentry includes: placing the electromagnetic coil around the tubular component; subsequently, validating an electromagnetic field profile of the electromagnetic coil using a probe temporarily inserted into the interior of the resonance cavity via an open end of the tubular component, the open end being an end selected from the group consisting of: the gun end, and the collector end; and/or subsequently, hermetically sealing, to the open end of the tubular component, a chamber selected from the group consisting of: the electron gun chamber, and the collector chamber. id="p-36" id="p-36" id="p-36"

[0036] For some implementations: the selected chamber is the electron gun chamber, and/or hermetically sealing the selected chamber to the open end of the tubular component subsequently to validating the electromagnetic field profile includes hermetically sealing the electron gun chamber to the open end of the tubular component subsequently to validating the electromagnetic field profile. id="p-37" id="p-37" id="p-37"

[0037] For some implementations: the selected chamber is the collector chamber, and/or hermetically sealing the selected chamber to the open end of the tubular component subsequently to validating the electromagnetic field profile includes hermetically sealing the collector chamber to the ASI10 open end of the tubular component subsequently to validating the electromagnetic field profile. id="p-38" id="p-38" id="p-38"

[0038] For some implementations, validating the electromagnetic field profile of the electromagnetic coil includes validating the electromagnetic field profile of the electromagnetic coil while the other chamber of the group is already hermetically sealed to its corresponding end of the tubular component. id="p-39" id="p-39" id="p-39"

[0039] For some implementations, the method further includes, subsequently to validating the electromagnetic field profile, hermetically sealing the other chamber of the group to its corresponding end of the tubular component. id="p-40" id="p-40" id="p-40"

[0040] For some implementations, assembling the gyrotron componentry includes: placing the electromagnetic coil around the tubular component; and/or subsequently, to an open end of the tubular component, hermetically sealing a chamber selected from the group consisting of: the electron gun chamber, and the collector chamber. id="p-41" id="p-41" id="p-41"

[0041] For some implementations, the selected chamber is the electron gun chamber, and hermetically sealing the selected chamber to the open end of the tubular component includes hermetically sealing the electron gun chamber to the open end of the tubular component. id="p-42" id="p-42" id="p-42"

[0042] For some implementations, the selected chamber is the collector chamber, and hermetically sealing the selected chamber to the open end of the tubular component includes hermetically sealing the collector chamber to the open end of the tubular component. id="p-43" id="p-43" id="p-43"

[0043] For some implementations, the method further includes, subsequently to placing the electromagnetic coil around the resonance cavity, and prior hermetically sealing the collector chamber to the open end of the tubular component, validating an electromagnetic field profile of the electromagnetic coil using a probe temporarily inserted ASI10 into the interior of the resonance cavity via the open end of the tubular component. id="p-44" id="p-44" id="p-44"

[0044] For some implementations, validating the electromagnetic field profile of the electromagnetic coil using the probe includes temporarily inserting the probe into the open end of the tubular component. id="p-45" id="p-45" id="p-45"

[0045] For some implementations, the method further includes operating a gyrotron that includes the gyrotron componentry. id="p-46" id="p-46" id="p-46"

[0046] For some implementations, the gyrotron is a continuous-wave gyrotron, and operating the gyrotron includes operating the continuous-wave gyrotron. id="p-47" id="p-47" id="p-47"

[0047] For some implementations, operating the gyrotron includes driving the electromagnet coil for at least one second continuously. id="p-48" id="p-48" id="p-48"

[0048] For some implementations, operating the gyrotron includes operating the gyrotron without cryogenic cooling of the electromagnetic coil. id="p-49" id="p-49" id="p-49"

[0049] There is further provided, in accordance with some implementations, apparatus, including componentry for a continuous-wave gyrotron, the apparatus including a vacuum tube and/or an electromagnetic coil. The vacuum tube may have a resonance cavity, an electron gun chamber, and/or a collector chamber. id="p-50" id="p-50" id="p-50"

[0050] The electron gun chamber may be hermetically sealed to a first end of the resonance cavity such that an interior of the electron gun chamber is continuous with an interior of the resonance cavity, the electron gun chamber having an electron-gun-chamber outer diameter. id="p-51" id="p-51" id="p-51"

[0051] The collector chamber may be hermetically sealed to a second end of the resonance cavity such that an interior of the collector chamber is continuous with the interior of the resonance cavity, the collector chamber having a collector-chamber outer diameter.

ASI10 id="p-52" id="p-52" id="p-52"

[0052] The electromagnetic coil may be disposed externally around the resonance cavity, and/or may have an inner diameter that is (i) smaller than the electron-gun-chamber outer diameter and (ii) smaller than the collector-chamber outer diameter. id="p-53" id="p-53" id="p-53"

[0053] For some implementations, the electron-gun-chamber outer diameter is greater than the collector-chamber outer diameter. id="p-54" id="p-54" id="p-54"

[0054] For some implementations, the collector-chamber outer diameter is greater than the electron-gun-chamber outer diameter. id="p-55" id="p-55" id="p-55"

[0055] For some implementations, the electromagnetic coil is not superconducting. id="p-56" id="p-56" id="p-56"

[0056] For some implementations, the apparatus includes the continuous-wave gyrotron. id="p-57" id="p-57" id="p-57"

[0057] For some implementations, the continuous-wave gyrotron includes a vacuum pump connected to the electron gun chamber. id="p-58" id="p-58" id="p-58"

[0058] For some implementations, the vacuum pump is a first vacuum pump, and the continuous-wave gyrotron includes a second vacuum pump connected to the collector chamber. id="p-59" id="p-59" id="p-59"

[0059] For some implementations, the continuous-wave gyrotron does not have cryogenic cooling of the electromagnetic coil. id="p-60" id="p-60" id="p-60"

[0060] For some implementations, the continuous-wave gyrotron is configured to operate the electromagnetic coil for at least one second continuously. id="p-61" id="p-61" id="p-61"

[0061] For some implementations, the vacuum tube has a vacuum port at the electron gun chamber. id="p-62" id="p-62" id="p-62"

[0062] For some implementations, the vacuum port is a first vacuum port, and the vacuum tube has a second vacuum port at the collector chamber. id="p-63" id="p-63" id="p-63"

[0063] There is further provided, in accordance with some implementations, a method for manufacturing componentry for a gyrotron, the method including: ASI10 placing an electromagnet coil externally around a tubular component; subsequently, assembling a vacuum tube that includes: a resonance cavity, defined at least in part by the tubular component, an electron gun chamber, hermetically sealed to a first end of the resonance cavity such that an interior of the electron gun chamber is continuous with an interior of the resonance cavity, and/or a collector chamber, hermetically sealed to a second end of the resonance cavity such that an interior of the collector chamber is continuous with the interior of the resonance cavity; and/or subsequently, evacuating the vacuum tube by: applying a vacuum to the vacuum tube, and/or baking the vacuum tube by selectively heating the electron gun chamber and the collector chamber. id="p-64" id="p-64" id="p-64"

[0064] For some implementations: the electron gun chamber has an electron-gun-chamber outer diameter, the collector chamber has a collector-chamber outer diameter, the coil defines an inner diameter that is smaller than the electron-gun-chamber outer diameter and the collector-chamber outer diameter, and/or placing the coil externally around the tubular component includes placing, externally around the tubular component, the coil that defines the inner diameter that is smaller than the electron-gun-chamber outer diameter and the collector-chamber outer diameter. id="p-65" id="p-65" id="p-65"

[0065] For some implementations: the tubular component has a tubular-component outer diameter, the coil has an inner diameter that is no more than 20 percent greater than the tubular-component outer diameter, and/or ASI10 placing the coil externally around the tubular component includes placing, externally around the tubular component, the coil that has the inner diameter that is no more than 20% greater than the tubular-component outer diameter. id="p-66" id="p-66" id="p-66"

[0066] The present invention will be more fully understood from the following detailed description of implementations thereof, taken together with the drawings, in which: BRIEF DESCRIPTION OF THE DRAWINGS id="p-67" id="p-67" id="p-67"

[0067] Figs. 1A-D are schematic illustrations representing some prior art techniques for preparing gyrotron componentry; and id="p-68" id="p-68" id="p-68"

[0068] Figs. 2A-E are schematic illustrations representing novel techniques for preparing gyrotron componentry, in accordance with some implementations of the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS id="p-69" id="p-69" id="p-69"

[0069] The present disclosure includes different variants of some elements. Variants of a given element typically have the same structure and/or function as each other except for any differences described. For any given element for which different variants are disclosed, the identical name is used for each variant, in order to denote that they are, in fact, variants the same given element. Unless stated otherwise, implementations of the devices, systems, and techniques described herein may include any arrangement in which one variant of an element is substituted with another identically-named variant of that element. Furthermore, throughout the figures, suffixes are used to denote different variants of the same element. Unless stated otherwise, such variants may be substituted with each other, mutatis mutandis. That is, unless stated otherwise, any element having a given reference numeral may be substituted with any other element (i.e. any other variant of the element) having the same reference numeral, independent of any suffix.

ASI10 id="p-70" id="p-70" id="p-70"

[0070] In order to avoid undue clutter from having too many reference numbers and lead lines on a particular drawing, some elements are introduced via one or more drawings and not explicitly identified in every other drawing that contains that element. id="p-71" id="p-71" id="p-71"

[0071] Gyrotrons comprise, inter alia, a vacuum tube and an electromagnetic coil (solenoid). An electron gun at one end of the vacuum tube (e.g. in an electron gun chamber) emits a beam of electrons that travels through a tubular resonant cavity situated within the electromagnetic coil. The electromagnetic coil provides a strong axial electromagnetic field that causes the electrons to move helically through the resonant cavity. Within the resonant cavity (e.g. where the electromagnetic field is at its maximum), the electrons radiate electromagnetic waves along the axis of the resonant cavity. The spent electrons are absorbed by a collector at the opposite end of the resonant cavity from the electron gun. The millimeter-wave radiation radiated by the electrons is formed into a beam that is converted by a mode converter and directed out of the vacuum tube (e.g. via a vacuum-tight window) for use. id="p-72" id="p-72" id="p-72"

[0072] Reference is made to Figs. 1A-D, which are schematic illustrations representing some prior art techniques for preparing gyrotron componentry 100. For simplicity, only the vacuum tube 110 and coil assembly 150 (comprising electromagnetic coil 152) of the gyrotron componentry are shown. Vacuum tube 110 comprises an electron gun chamber 120 (which contains an electron gun; not shown), a collector chamber 140 (which contains and/or serves as the collector of the gyrotron), and a resonance cavity 130 therebetween. Resonance cavity 130 comprises, and/or is at least partly defined by, a tubular component 132. Resonance cavity 130 may further comprise, and/or be partly defined by, a conductive liner 134 disposed within tubular component 132. Liner 134 may also be tubular. Tubular component 1may be primarily structural and/or configured to be vacuum-tight, whereas liner 134 may have a primarily electromagnetic function.

ASI10 Tubular component 132 may be formed from stainless steel (as may electron gun chamber 120 and/or collector chamber 140), whereas liner 134 may be formed from copper. id="p-73" id="p-73" id="p-73"

[0073] For simplicity, the window of vacuum tube 110, via which the millimeter-wave beam will exit the vacuum tube during operation of the gyrotron, is not shown. id="p-74" id="p-74" id="p-74"

[0074] Fig. 1B shows vacuum tube 110 assembled and hermetically sealed – e.g. with one end of tubular component 132 hermetically sealed to electron gun chamber 120, and the other end hermetically sealed to collector chamber 140. Once assembled and hermetically sealed, vacuum tube 110 is evacuated by applying a vacuum and baking (or "baking off") the vacuum tube (Fig. 1C). Vacuum tube 110 may have a vacuum port 112 via which the vacuum is applied. As schematically illustrated by box 20, baking is performed by heating the entire vacuum tube to an elevated temperature and holding it at the elevated temperature for duration of several days (or even weeks). The elevated temperature may be at least 250 degrees C (e.g. 300-400 degrees C). Baking and implementation of the vacuum may be performed simultaneously or sequentially. id="p-75" id="p-75" id="p-75"

[0075] Coil assembly 150 has a central lumen 154 – e.g. is substantially tubular. Subsequently to evacuation of vacuum tube 110, coil assembly 150 is placed around (e.g. coaxially around) resonance cavity 130 – i.e. such that the resonance cavity is disposed within lumen 154 (Fig. 1D). The baking of vacuum tube 110 is performed prior to this placement of coil assembly 150 due, at least in part, to heat sensitivity of electromagnetic coil 152. In order to place coil assembly 150 around resonance cavity 130, the coil assembly is passed over one of the chambers at either end of the resonance cavity – i.e. with the chamber passing through lumen 154 of the coil assembly. Thus, an inner diameter d1 of coil assembly 150 (and therefore an inner diameter of electromagnetic coil 152) is necessarily greater than an outer diameter of the chamber over which it is passed. In the ASI10 illustrated example, coil assembly 150 is to be passed over electron gun chamber 120, and thus inner diameter d4 is necessarily greater than an outer diameter d2 of the electron gun chamber. (Similarly, for implementations in which coil assembly 150 is to be passed over collector chamber 140, inner diameter d4 is necessarily greater than an outer diameter d5 of the collector chamber.) id="p-76" id="p-76" id="p-76"

[0076] In the example shown, the chamber over which coil assembly 150 is passed is electron gun chamber 120 – e.g. because, in this example, diameter d2 of electron gun chamber 120 is shown as being a smaller than diameter d5 of collector chamber 140. In order to facilitate passage of coil assembly 150 over the chamber, vacuum port 112 may be positioned at the other chamber – e.g. so as not to necessitate further widening of lumen 154. Hence, in the example shown, vacuum port 112 is at collector chamber 140. For the simplicity, the vacuum pump to which vacuum port 112 is connected is not shown. It is to be noted that the vacuum pump normally remains connected to vacuum port 112, and actively applying the vacuum, persistently. id="p-77" id="p-77" id="p-77"

[0077] Because chambers 120 and 140 are typically wider than resonance cavity 130, such techniques disadvantageously require electromagnetic coil 152 to be wider, and therefore further away from resonance cavity 130, than would be otherwise necessary to accommodate the resonance cavity within lumen 154. For example, inner diameter dmay be more than twice as large as (e.g. more than 5 times larger than, such as more than 10 times larger than) an outer diameter d4 of resonance cavity 130 (e.g. of tubular component 132 thereof). That is, a gap d3 between resonance cavity 130 (e.g. tubular component 132) and coil assembly 150, necessary for the assembling of the gyrotron, is greater than necessary (or desirable) for the functioning of the gyrotron. Moreover, electromagnetic coil 152 must be sufficiently powerful to overcome gap d3 – i.e. to have its influence on resonance cavity 130 across gap d3. In order to be sufficiently powerful, at least for a continuous-wave gyrotron, electromagnetic coil 152 is ASI10 often superconducting and/or requires cryogenic cooling. Thus, coil assembly 150 is typically pre-assembled to contain electromagnetic coil 152 and cryogenic cooling components. Further disadvantageously, superconducting and/or cryogenically-cooled electromagnetic coils must typically remain cooled persistently as opposed to, for example, only when the gyrotron is required. id="p-78" id="p-78" id="p-78"

[0078] Figs. 2A-E are schematic illustrations representing novel techniques for preparing gyrotron componentry 200, in accordance with some implementations of the present disclosure. Componentry 2comprises a coil assembly 150a comprising an electromagnetic coil 152a; and a vacuum tube 110a that comprises an electron gun chamber 120a, a collector chamber 140a, and a resonance cavity 130a therebetween. Resonance cavity 130a comprises, and/or is at least partly defined by, a tubular component 132a, and may further comprise a conductive liner 134a disposed within tubular component 132a. id="p-79" id="p-79" id="p-79"

[0079] For each component of componentry 200, the suffix "a" denotes that the component is a variant of the identically-named component of componentry 100 that lacks the suffix. Except as noted, each such variant may be as described for its counterpart in componentry 100 - e.g. may have the same general structure and serve the same function within the gyrotron in which the componentry is used. For example, electron gun chamber 120a, tubular component 132a, and collector chamber 140a may be identical to electron gun chamber 120, tubular component 132, and collector chamber 140. Outer diameter d4a of tubular component 132a may be identical to outer diameter dof tubular component 132. id="p-80" id="p-80" id="p-80"

[0080] Inter alia, the techniques described with reference to Figs. 2A-E allow an inner diameter d1a of coil assembly 150a to be independent of (and thereby smaller than) a diameter d2a of electron gun chamber 120a and/or a diameter d5a of collector chamber 140a, and thereby advantageously allow a gap d3a, between resonance cavity 130a (e.g. tubular component 132a) and coil assembly 150a, to be ASI10 substantially smaller than gap d3 – i.e. substantially smaller than is possible for componentry 100 and/or than can be achieved using the technique described with respect to Figs. 1A-D. This may advantageously reduce the power required for operation of the gyrotron, which may consequently obviate the need for cryogenic cooling of electromagnetic coil 152a – e.g. even for continuous-wave implementations (e.g. even in a continuous-wave gyrotron) – e.g. simple water- or oil-cooling may suffice. For example, electromagnetic coil 152a may not be a superconducting electromagnetic coil. Thus, a gyrotron that utilizes componentry 200 (and/or whose componentry is assembled using the technique described with reference to Figs. 2A-E) may advantageously be compatible with powering-on and powering-off on demand, rather than requiring persistent power and cooling, thereby potentially widening the range of implementations for which such a gyrotron is practical. id="p-81" id="p-81" id="p-81"

[0081] As shown in Fig. 2B, coil assembly 150a is placed around resonance cavity 130a – i.e. such that the resonance cavity is disposed within lumen 154a. However, unlike the technique described with respect to Figs. 1A-D, this placement is performed prior to attaching (and hermetically sealing) at least one of the chambers to its respective end of resonance cavity 130a. In the example shown, this placement is performed prior to attaching electron gun chamber 120a to its end of the resonance cavity. Alternatively or additionally, this placement may be performed prior to attaching collector chamber 140a to its end of the resonance cavity. Due to the absence of the chamber, inner diameter d1a of coil assembly 150a need only be sufficiently great to be passed over resonance cavity 130a (e.g. tubular component 132 thereof). For example, inner diameter d1a of coil assembly 150a (and/or an inner diameter of coil 152a) may be no more than 20 percent greater (e.g. no more than 10 percent greater) than an outer diameter d4a of resonance cavity 130a (e.g. of tubular component 132 thereof). Thus, and as noted hereinabove, gap d3a between resonance cavity 130a (e.g. tubular component 132a) and coil assembly ASI10 150a (and thereby coil 152a) can be substantially smaller than is possible for componentry 100 and/or than can be achieved using the technique described with respect to Figs. 1A-D. id="p-82" id="p-82" id="p-82"

[0082] Another advantage provided by placing the coil assembly around the resonance cavity while at least one end of resonance cavity 130a remains open (due to the absence of at least one of chambers 1and 140) is that it is possible to assess (e.g. validate) the electromagnetic field profile of the electromagnetic coil in situ by temporarily inserting a probe 30 into the interior of resonance cavity 130a via the open end of the resonance cavity – e.g. as illustrated in Fig. 2C. This may allow for adjustment of electromagnetic coil 152a, repositioning of coil assembly 150a, and/or switching between coil assemblies. id="p-83" id="p-83" id="p-83"

[0083] Once coil assembly 150a is in place around resonance cavity 130a, the remaining chamber(s) is/are coupled and hermetically sealed to the respective end(s) of the resonance cavity 130, thereby hermetically sealing vacuum tube 110a (Fig. 2D). In the example shown, this remaining cavity is electron gun cavity 120a. id="p-84" id="p-84" id="p-84"

[0084] Subsequently, vacuum tube 110 is evacuated (Fig. 2E). As noted hereinabove, evacuation of a vacuum tube is performed by applying a vacuum and baking. As also noted hereinabove, heat sensitivity of electromagnetic coil 152a typically precludes placement of the electromagnet coil prior to baking. In the technique of Figs. 2A-E this is addressed by selectively heating electron gun chamber 120a and collector chamber 140a – e.g. without heating the central region of the assembled componentry such as coil assembly 150a and/or resonance cavity 130a. This is represented by separate boxes 20a' and 20a''. id="p-85" id="p-85" id="p-85"

[0085] Such selective heating may be achieved by, for example, using separate ovens for each chamber, or by placing heating elements and/or heating mantles around each chamber. id="p-86" id="p-86" id="p-86"

[0086] For some implementations, the baking involves selectively heating the electron gun chamber and the collector chamber to a ASI10 temperature of at least 250 degrees C (e.g. at least 350 degrees C). For some such implementations, the electron gun chamber and the collector chamber are maintained at this temperature for at least day (e.g. for at least 2 days). For some implementations, this temperature is maintained while the temperature of resonance cavity 130a (e.g. of tubular component 132a) does not exceed 100 degrees, e.g. does not exceed 80, e.g. not more than 50 degrees C. For some applications, cooling (e.g. water or oil cooling, thermoelectric cooling, or vapor-compression refrigeration) is applied to resonance cavity 130a and/or to coil assembly 150a during baking. id="p-87" id="p-87" id="p-87"

[0087] It has been determined by the inventors that baking by such selective heating can be sufficient – e.g. that excluding the resonant cavity region of the vacuum tube from the bake is not materially detrimental to the evacuation of the vacuum tube, or at least that any such detriment is outweighed by the benefits provided by the technique described with reference to Figs. 2A-E. id="p-88" id="p-88" id="p-88"

[0088] As noted hereinabove, the techniques described with reference to Figs. 2A-E provides for independence between the inner diameter of coil assembly 150a and the width (e.g. diameter) of electron gun chamber 120a and/or collector chamber 140a. Such independence, in addition to allowing for an advantageously-smaller coil assembly diameter d1a, similarly allows for the electron gun chamber and/or the collector chamber to be wider. That is, whereas for prior art techniques a tension (e.g. a trade-off) exists between the coil assembly inner diameter and the width of at least one of the chambers, the techniques disclosed herein relieve this tension (e.g. the trade-off). For example, the techniques disclosed herein may allow for both the electron gun chamber and the collector chamber to be wider than would accommodate passing-over of a coil assembly having a practical or feasible inner diameter, thereby reducing certain design constraints on the chambers. For example, a wider electron gun chamber may advantageously allow for greater spacing between electron gun ASI10 electrodes (e.g. allowing for operation at a higher voltage) and/or larger electron gun electrodes (e.g. allowing for reduced density of the emitted current). Likewise, a wider collector chamber may advantageously reduce the electron density impacting the collector and/or the temperature of the collector (e.g. reducing wear and increasing lifespan of the collector). id="p-89" id="p-89" id="p-89"

[0089] For some applications, diameter d2a and/or diameter d5a is at least twice as great (e.g. at least 5 times as great, such as at least 10 times as great) as diameter d1a. id="p-90" id="p-90" id="p-90"

[0090] Similarly, because inner diameter d1a is not dependent on the width (e.g. diameter d2a) of electron gun chamber 120a (i.e. because coil assembly 150a is not passed over the electron gun chamber), the electron gun chamber may be provided with a vacuum port 112a' in addition to, or instead of, vacuum port 112a of collector chamber 140a. This may advantageously further improve evacuation of vacuum tube 110a. id="p-91" id="p-91" id="p-91"

[0091] Therefore, in accordance with some implementations, there is provided a method that comprises (1) assembling gyrotron componentry that includes (a) a vacuum tube that includes (i) a resonance cavity defined at least in part by a tubular component, (ii) an electron gun chamber, hermetically sealed to a gun end of the tubular component such that an interior of the electron gun chamber is continuous with an interior of the resonance cavity, and (iii) a collector chamber, hermetically sealed to a collector end of the tubular component such that an interior of the collector chamber is continuous with the interior of the resonance cavity; and (b) an electromagnet coil disposed externally around the tubular component; and (2) subsequently, evacuating the vacuum tube by (a) applying a vacuum to the vacuum tube, and (b) baking the vacuum tube by selectively heating the electron gun chamber and the collector chamber.

ASI10 id="p-92" id="p-92" id="p-92"

[0092] There is also provided, in accordance with some implementations, a method for manufacturing componentry for a gyrotron, the method comprising (1) placing an electromagnet coil externally around a tubular component; (2) subsequently, assembling a vacuum tube that includes (a) a resonance cavity, defined at least in part by the tubular component, (b) an electron gun chamber, hermetically sealed to a first end of the resonance cavity such that an interior of the electron gun chamber is continuous with an interior of the resonance cavity, and (c) a collector chamber, hermetically sealed to a second end of the resonance cavity such that an interior of the collector chamber is continuous with the interior of the resonance cavity; and (3) subsequently, evacuating the vacuum tube by (a) applying a vacuum to the vacuum tube, and (b) baking the vacuum tube by selectively heating the electron gun chamber and the collector chamber. id="p-93" id="p-93" id="p-93"

[0093] At least in part due to the techniques described with reference to Figs. 2A-E, there is also provided, in accordance with some implementations, componentry for a continuous-wave gyrotron, the componentry comprising (1) a vacuum tube that has (a) a resonance cavity, (b) an electron gun chamber, hermetically sealed to a first end of the resonance cavity such that an interior of the electron gun chamber is continuous with an interior of the resonance cavity, the electron gun chamber having an electron-gun-chamber outer diameter, and (c) a collector chamber, hermetically sealed to a second end of the resonance cavity such that an interior of the collector chamber is continuous with the interior of the resonance cavity, the collector chamber having a collector-chamber outer diameter; and (2) an electromagnetic coil, disposed externally around the resonance cavity, and having an inner diameter that is smaller than the electron-gun-chamber outer diameter and smaller than the collector-chamber outer diameter.

ASI10 id="p-94" id="p-94" id="p-94"

[0094] Reference is again made to Figs. 2A-E. Although coil assembly 150a is shown as a pre-formed component that is placed around resonance cavity 130a by passing it over (e.g. sliding it onto) the resonance cavity, for some applications the coil assembly may be assembled in situ – e.g. by winding electromagnetic coil 152a onto tubular component 132. This, too, is facilitated by the technique described with reference to Figs. 2A-E because (i) the electromagnetic field profile of the freshly-assembled coil assembly (e.g. the freshly-wound coil) may be assessed (e.g. verified) using probe 30 via the end of resonance cavity 130a has not yet been closed after the assembly of the coil assembly, and/or (ii) the subsequent baking of vacuum tube 110a via selective heating of electron gun chamber 120a and collector chamber 140a protects the coil assembly from heat damage. id="p-95" id="p-95" id="p-95"

[0095] It is to be noted that the techniques described with reference to Figs. 2A-E are applicable to various vacuum tubes, including various gyrotrons. However, it is hypothesized that they are particularly useful for vacuum tubes for continuous-wave gyrotrons – e.g. that are configured to operate the electromagnetic coil continuously for durations of at least one second. id="p-96" id="p-96" id="p-96"

[0096] The described systems, apparatuses, devices, methods, etc. should not be construed as limiting in any way. Instead, the present disclosure is directed toward all novel and nonobvious features and aspects of the various disclosed implementations and implementations, alone and in various combinations and sub-combinations with one another. The disclosed systems, apparatuses, devices, methods, etc. are not limited to any specific aspect, feature, or combination thereof, nor do the disclosed systems, apparatuses, devices, methods, etc. require that any one or more specific advantages be present or problems be solved. id="p-97" id="p-97" id="p-97"

[0097] Although the operations of some of the disclosed methods are described in a particular, sequential order for convenient presentation, it should be understood that this manner of description ASI10 encompasses rearrangement, unless a particular ordering is required by specific language set forth herein. For example, operations described sequentially can in some cases be rearranged or performed concurrently. Moreover, for the sake of simplicity, the attached figures may not show the various ways in which the disclosed systems, apparatuses, devices, methods, etc. can be used in conjunction with other systems, apparatuses, devices, methods, etc. id="p-98" id="p-98" id="p-98"

[0098] The present invention is not limited to the examples that have been particularly shown and described hereinabove. Rather, the scope of the present invention includes both combinations and subcombinations of the various features described hereinabove, as well as variations and modifications thereof that are not in the prior art, which would occur to persons skilled in the art upon reading the foregoing description.

Claims (51)

IL 305432 | ASI10 AMENDED CLAIMS (CLEAN)

1. A method, comprising: assembling gyrotron componentry that includes: a vacuum tube that includes: a resonance cavity, defined at least in part by a tubular component, an electron gun chamber, hermetically sealed to a gun end of the tubular component such that an interior of the electron gun chamber is continuous with an interior of the resonance cavity, and a collector chamber, hermetically sealed to a collector end of the tubular component such that an interior of the collector chamber is continuous with the interior of the resonance cavity, and an electromagnet coil disposed externally around the tubular component; and subsequently to said assembling of said gyrotron componentry, evacuating the vacuum tube by: applying a vacuum to the vacuum tube, and baking the vacuum tube by selectively heating the electron gun chamber and the collector chamber.

2. The method according to claim 1, wherein the electromagnet coil is not superconducting, and wherein assembling the gyrotron componentry comprises assembling the gyrotron componentry that comprises the electromagnetic coil that is not superconducting.

3. The method according to any one of claims 1-2, wherein baking the vacuum tube comprises baking the vacuum tube while applying the vacuum to the vacuum tube. IL 305432 | ASI10

4. The method according to any one of claims 1-3, wherein applying the vacuum to the vacuum tube comprises applying the vacuum via a port on the electron gun chamber.

5. The method according to any one of claims 1-4, wherein applying the vacuum to the vacuum tube comprises applying the vacuum via a port on the collector chamber.

6. The method according to any one of claims 1-5, wherein applying the vacuum to the vacuum tube comprises applying the vacuum via a first port on the electron gun chamber and a second port on the collector chamber.

7. The method according to any one of claims 1-6, wherein assembling the gyrotron componentry comprises forming the electromagnetic coil by winding onto the tubular component.

8. The method according to any one of claims 1-6, wherein assembling the gyrotron componentry comprises sliding the electromagnetic coil onto the tubular component.

9. The method according to any one of claims 1-8, wherein selectively heating the electron gun chamber and the collector chamber comprises heating the electron gun chamber and the collector chamber using at least one heating mantle.

10. The method according to any one of claims 1-9, wherein selectively heating the electron gun chamber and the collector chamber comprises applying cooling to the resonance cavity.

11. The method according to any one of claims 1-10, wherein: the resonance cavity comprises further includes a conductive liner, and assembling the gyrotron componentry comprises inserting the conductive liner into the tubular component.

12. The method according to any one of claims 1-11, wherein the gyrotron componentry is componentry of a continuous-wave gyrotron. IL 305432 | ASI10

13. The method according to any one of claims 1-12, further comprising utilizing the gyrotron componentry in a gyrotron.

14. The method according to any one of claims 1-13, further comprising assembling a gyrotron that includes the gyrotron componentry.

15. The method according to any one of claims 1-14, wherein applying the vacuum comprises applying the vacuum at the electron gun chamber.

16. The method according to claim 15, wherein applying the vacuum comprises applying the vacuum both at the electron gun chamber and at the collector chamber.

17. The method according to claim 16, wherein applying the vacuum comprises applying the vacuum both (i) via a first vacuum port at the electron gun chamber, and (ii) via a second vacuum port at the collector chamber.

18. The method according to claim 16, wherein applying the vacuum comprises applying the vacuum both (i) via a first vacuum pump connected to the electron gun chamber, and (ii) via a second vacuum pump connected to the collector chamber.

19. The method according to any one of claims 1-18, wherein selectively heating the electron gun chamber and the collector chamber comprises selectively heating the electron gun chamber and the collector chamber to a temperature of at least 250 degrees C.

20. The method according to claim 19, wherein the temperature is at least 350 degrees C, and heating the electron gun chamber and the collector chamber to the temperature comprises heating the electron gun chamber and the collector chamber to the temperature of at least 350 degrees C.

21. The method according to claim 19, wherein heating the electron gun chamber and the collector chamber comprises heating the electron gun chamber and the collector chamber while a temperature of the tubular component does not exceed 80 degrees C. IL 305432 | ASI10

22. The method according to claim 19, wherein baking the vacuum tube comprises holding the electron gun chamber and the collector chamber at the temperature for at least 1 day.

23. The method according to claim 19, wherein holding the electron gun chamber and the collector chamber at the temperature for at least day comprises holding the electron gun chamber and the collector chamber at the temperature for at least 2 days.

24. The method according to any one of claims 1-23, wherein assembling the gyrotron componentry comprises: placing the electromagnetic coil around the tubular component; subsequently, validating an electromagnetic field profile of the electromagnetic coil using a probe temporarily inserted into the interior of the resonance cavity via an open end of the tubular component, the open end being an end selected from the group consisting of: the gun end, and the collector end; and subsequently, hermetically sealing, to the open end of the tubular component, a chamber selected from the group consisting of: the electron gun chamber, and the collector chamber.

25. The method according to claim 24, wherein: the selected chamber is the electron gun chamber, and hermetically sealing the selected chamber to the open end of the tubular component subsequently to validating the electromagnetic field profile comprises hermetically sealing the electron gun chamber to the open end of the tubular component subsequently to validating the electromagnetic field profile.

26. The method according to claim 24, wherein: the selected chamber is the collector chamber, and hermetically sealing the selected chamber to the open end of the tubular component subsequently to validating the electromagnetic field profile comprises hermetically sealing the collector chamber to the open end of the tubular component subsequently to validating the electromagnetic field profile. IL 305432 | ASI10

27. The method according to claim 24, wherein validating the electromagnetic field profile of the electromagnetic coil comprises validating the electromagnetic field profile of the electromagnetic coil while the other chamber of the group is already hermetically sealed to its corresponding end of the tubular component.

28. The method according to claim 24, further comprising, subsequently to validating the electromagnetic field profile, hermetically sealing the other chamber of the group to its corresponding end of the tubular component.

29. The method according to any one of claims 1-28, wherein assembling the gyrotron componentry comprises: placing the electromagnetic coil around the tubular component; and subsequently, to an open end of the tubular component, hermetically sealing a chamber selected from the group consisting of: the electron gun chamber, and the collector chamber.

30. The method according to claim 29, wherein the selected chamber is the electron gun chamber, and hermetically sealing the selected chamber to the open end of the tubular component comprises hermetically sealing the electron gun chamber to the open end of the tubular component.

31. The method according to claim 29, wherein the selected chamber is the collector chamber, and hermetically sealing the selected chamber to the open end of the tubular component comprises hermetically sealing the collector chamber to the open end of the tubular component.

32. The method according to claim 29, further comprising, subsequently to placing the electromagnetic coil around the resonance cavity, and prior hermetically sealing the collector chamber to the open end of the tubular component, validating an electromagnetic field profile of the electromagnetic coil using a probe temporarily inserted into the interior of the resonance cavity via the open end of the tubular component. IL 305432 | ASI10

33. The method according to claim 32, wherein validating the electromagnetic field profile of the electromagnetic coil using the probe comprises temporarily inserting the probe into the open end of the tubular component.

34. The method according to any one of claims 1-33, further comprising operating a gyrotron that includes the gyrotron componentry.

35. The method according to claim 34, wherein the gyrotron is a continuous-wave gyrotron, and wherein operating the gyrotron comprises operating the continuous-wave gyrotron.

36. The method according to claim 34, wherein operating the gyrotron comprises driving the electromagnet coil for at least one second continuously.

37. The method according to claim 34, wherein operating the gyrotron comprises operating the gyrotron without cryogenic cooling of the electromagnetic coil.

38. Apparatus, comprising componentry for a continuous-wave gyrotron, the apparatus comprising: a vacuum tube that has: a resonance cavity, an electron gun chamber, hermetically sealed to a first end of the resonance cavity such that an interior of the electron gun chamber is continuous with an interior of the resonance cavity, the electron gun chamber having an electron-gun-chamber outer diameter, and a collector chamber, hermetically sealed to a second end of the resonance cavity such that an interior of the collector chamber is continuous with the interior of the resonance cavity, the collector chamber having a collector-chamber outer diameter; and IL 305432 | ASI10 an electromagnetic coil, disposed externally around the resonance cavity, and having an inner diameter that is smaller than the electron-gun-chamber outer diameter and smaller than the collector-chamber outer diameter.

39. The apparatus according to claim 38, wherein the electron-gun-chamber outer diameter is greater than the collector-chamber outer diameter.

40. The apparatus according to claim 38, wherein the collector-chamber outer diameter is greater than the electron-gun-chamber outer diameter.

41. The apparatus according to any one of claims 38-40, wherein the electromagnetic coil is not superconducting.

42. The apparatus according to any one of claims 38-41, wherein the apparatus comprises the continuous-wave gyrotron.

43. The apparatus according to claim 42, wherein the continuous-wave gyrotron comprises a vacuum pump connected to the electron gun chamber.

44. The apparatus according to claim 43, wherein the vacuum pump is a first vacuum pump, and wherein the continuous-wave gyrotron comprises a second vacuum pump connected to the collector chamber.

45. The apparatus according to claim 42, wherein the continuous-wave gyrotron does not have cryogenic cooling of the electromagnetic coil.

46. The apparatus according to claim 42, wherein the continuous-wave gyrotron is configured to operate the electromagnetic coil for at least one second continuously.

47. The apparatus according to any one of claims 38-46, wherein the vacuum tube has a vacuum port at the electron gun chamber.

48. The apparatus according to claim 47, wherein the vacuum port is a first vacuum port, and wherein the vacuum tube has a second vacuum port at the collector chamber. IL 305432 | ASI10

49. A method for manufacturing componentry for a gyrotron, the method comprising: placing an electromagnet coil externally around a tubular component; subsequently to said placing of said electromagnet coil, assembling a vacuum tube that includes: a resonance cavity, defined at least in part by the tubular component, an electron gun chamber, hermetically sealed to a first end of the resonance cavity such that an interior of the electron gun chamber is continuous with an interior of the resonance cavity, and a collector chamber, hermetically sealed to a second end of the resonance cavity such that an interior of the collector chamber is continuous with the interior of the resonance cavity; and subsequently to said assembling of said vacuum tube, evacuating the vacuum tube by: applying a vacuum to the vacuum tube, and baking the vacuum tube by selectively heating the electron gun chamber and the collector chamber.

50. The method according to claim 49, wherein: the electron gun chamber has an electron-gun-chamber outer diameter, the collector chamber has a collector-chamber outer diameter, the coil defines an inner diameter that is smaller than the electron-gun-chamber outer diameter and the collector-chamber outer diameter, and placing the coil externally around the tubular component comprises placing, externally around the tubular component, the coil that defines the inner diameter that is smaller than the electron-gun-chamber outer diameter and the collector-chamber outer diameter. IL 305432 | ASI10

51. The method according to any one of claims 49-50, wherein: the tubular component has a tubular-component outer diameter, the coil has an inner diameter that is no more than 20 percent greater than the tubular-component outer diameter, and placing the coil externally around the tubular component comprises placing, externally around the tubular component, the coil that has the inner diameter that is no more than 20% greater than the tubular-component outer diameter.