Gyrotron system comprising integrated superconducting magnet and cavity

Abstract

A gyrotron system (1) comprises a housing (2), an electron gun (3) configured to produce an electron beam, at least one magnet (4) configured to produce a magnetic field, and a cavity (5) configured to receive the electron beam, and wherein microwaves and / or Terahertz waves (16) are generatable in the cavity (5) by a resonance coupling between the electron beam and the magnetic field produced by the magnet (4). The magnet (4) is a superconducting magnet that is configured to exhibit superconductivity upon cooling below its critical temperature and that is arranged around the cavity (5), and the cavity (5) and the superconducting magnet (4) are arranged within the housing (2).

Description

[0001] TITLE

[0002] GYROTRON SYSTEM COMPRISING INTEGRATED SUPERCONDUCTING MAGNET AND CAVITY

[0003] TECHNICAL FIELD

[0004] The present invention relates to a gyrotron system according to claim 1.

[0005] PRIOR ART

[0006] A gyrotron oscillator is a fast-wave device, in which the phase velocity of the wave is larger than the speed of light. Its operation is based on the stimulated Bremsstrahlung radiation of electrons gyrating in a homogeneous magnetic field. The interaction in the cavity can operate close to the fundamental cyclotron frequency and at its harmonics. Besides their intrinsic simplicity and high efficiency, the main advantage of gyrotrons over competing sources resides in that the physical size of the cavity can be much larger than wavelength by means of the selection of a high order cavity mode. This is the main reason that a gyrotron is the dominant microwave source in the high power and high frequency regime.

[0007] Operating at the fundamental harmonic, gyrotrons offer significant advantages in mode stability and power generation compared to those operating at higher harmonics. This stems from fundamental factors: interaction efficiency diminishes at higher harmonics, leading to lower stability due to competition with first harmonic modes and increased ohmic losses. However, realizing gyrotrons at fundamental harmonics within the "THz Gap" frequency range necessitates magnets capable of generating exceptionally strong magnetic fields, which are either not available commercially or prohibitively expensive. Consequently, the development of gyrotrons operating at such high frequencies is predominantly confined to second and third harmonics, albeit with substantially reduced power output. As a result, all available DNP NMR spectrometers operating at very high frequencies currently rely on second or higher harmonic gyrotrons or with pulsed magnetic field. The challenge in fabricating high magnetic field gyrotron magnets is correlated to the assembly of the gyrotron. Each gyrotron system comprises two primary components: the housing and the superconducting magnet responsible for generating the requisite magnetic field. These superconducting magnets are typically crafted by specialized industrial firms. Three key characteristics define the quality and functionality of a gyrotron magnet:

[0008] - Maximum Magnetic Field: This parameter dictates the frequency of the output microwaves.

[0009] - Magnetic Field Profile: Crucial for determining electron trajectories and, consequently, the properties of the electron beam upon entering the cavity, thereby influencing efficiency and gyrotron performance.

[0010] - Warm Bore Hole: Essential for seamlessly inserting the housing into the magnet. Proper positioning is critical, with the center of the gyrotron cavity ideally aligned with the location of maximum magnetic field strength.

[0011] Given the need for the insertion of the housing from one side of the warm bore hole, its dimensions are determined by the outer radius of the electron gun or, alternatively, the outer radius of the collector, instead of the diameter of the cavity where the high magnetic field is needed for the gyrotron operation. Typically, the size of the electron gun determines the bore hole dimensions due to its smaller dimensions compared to the collector.

[0012] The complexity and cost associated with magnet fabrication increases significantly as the radius of the bore hole - or, equivalently, the inner radius of the coils within the magnet - increases. A larger inner radius necessitates a greater number of turns, a longer superconducting cable for coil fabrication, heightened forces between the coils, an expanded stray magnetic field, and ultimately, a significant rise in both complexity and cost throughout the magnet's construction process.

[0013] SUMMARY OF THE INVENTION

[0014] It is an object of the present invention to provide a gyrotron system of enhanced power while being less complex and associated with lower manufacturing costs and in particular providing the possibility of developing high power gyrotrons operating in THz gap.

[0015] This object is achieved with a gyrotron system according to claim 1. That is a gyrotron system is provided, wherein said gyrotron system comprises a housing, an electron gun configured to produce an electron beam, at least one magnet configured to produce a magnetic field, and a cavity configured to receive the electron beam. Microwaves and / or Terahertz waves are generatable in the cavity by a resonance coupling between the electron beam and the magnetic field produced by the magnet. The magnet is a superconducting magnet that is configured to exhibit superconductivity upon cooling below a critical temperature of the superconducting magnet. The superconducting magnet is arranged around the cavity. The cavity and the superconducting magnet are arranged within the housing.

[0016] That is, the present invention is based on the insight that the magnetic field being necessary for the gyrotron operation, i.e., for generating the electromagnetic radiation, can be provided by at least one superconducting magnet, and wherein said superconducting magnet is arranged around the cavity. Moreover, the cavity and the superconducting magnet are arranged inside the housing, i.e., inside a common structure. In other words, the superconducting magnet and the cavity are integrated in the housing, which effectively unifies the fabrication of both the superconducting magnet and other components of the gyrotron system into a single structure.

[0017] That is, the housing preferably forms a common structure that encloses the cavity and the superconducting magnet. Additionally or alternatively, the housing is preferably monolithic and / or a single-piece element. Additionally or alternatively, the cavity and the superconducting magnet are preferably integrated into the housing.

[0018] The superconducting magnet and the cavity preferably form a common component. Additionally or alternatively, the superconducting magnet and the cavity are preferably inseparably and / or non-destructively connected to each other. In other words, the superconducting magnet and the cavity preferably form a single, inseparable component.

[0019] The superconducting magnet and the cavity are preferably configured such that they are not independently movable of each other. Additionally or alternatively, the superconducting magnet is preferably immovable with respect to the cavity. Additionally or alternatively, the cavity is preferably immovable with respect to the superconducting magnet.

[0020] As a consequently, no mechanical alignment between the superconducting magnet and the cavity is possible nor necessary. Instead, it is preferred that the superconducting magnet together with the cavity are movable for instance with respect to the electron gun or other components of the gyrotron system, wherein a common alignment of both the superconducting magnet and the cavity at a same time is possible.

[0021] This novel technological approach significantly streamlines magnet fabrication, as superconducting magnets such as high-temperature superconducting (HTS) coils with a tiny inner radius can be directly integrated onto the cavity, precisely where the highest magnetic field is required. This results in many advantages: (i) Simplified and cost-effective magnet fabrication, (ii) Rapid dissipation of stray magnetic fields, (iii) Compact overall structure, (iv) A small inductance of the compact magnet enables rapid magnetic field variation and fast frequency tunability, (v) Optimal alignment of the magnetic field and the cavity by construction.

[0022] The superconductive magnet is preferably configured to generate a magnetic field that enables the generation of electromagnetic radiation being high-frequency waves having a frequency in the microwave range and / or the Terahertz range and / or a frequency in the range of 0.3 THz to 3 THz and / or a wavelength in the range of 1 Millimeter to 100 Micrometer. Hence, the gyrotron system according to the invention has an enhanced power as compared to the gyrotron systems of the prior art when operating in the THz frequency range and at the fundamental harmonic.

[0023] The gyrotron system preferably further comprises at least one joint cooling device that is configured to jointly cool the superconducting magnet and the cavity.

[0024] The joint cooling device can be a chamber such as a cryostat configured to receive at least one cooling fluid and / or configured to at least partially receive the housing in the region of the cavity and the superconducting magnet. Alternatively, the joint cooling device can be cryogen-free and / or can be configured to at least one of conductively connect to the cavity and the superconducting magnet and to dissipate heat from the cavity and the superconducting magnet.

[0025] Various cooling fluids are conceivable and well-known in the art. For instance, the cooling fluid can be liquid nitrogen or liquid helium that can be provided in the joint cooling device such as the cryostat, and wherein the cryostat in turn at least partially receives the housing and thereby cools the cavity and the superconducting coil being arranged within the housing in a joint manner. However, it is likewise conceivable that said joint cooling is achieved with a cryogen-free common cooling device. For instance, the joint cooling device can be configured to conductively connect to the cavity as well as to the superconducting magnet and to dissipate heat from the cavity and the superconducting magnet. That is, the joint cooling device can comprise at least one heat dissipating element such as a so-called cooling head, for instance in the form of a copper ribbon, that is configured to dissipate heat from the superconducting magnet and the cavity via thermal conductivity.

[0026] The joint cooling device is preferably configured to jointly cool the cavity and the superconducting magnet such, that a temperature of the superconducting magnet and of the cavity is the same.

[0027] That is, in a first embodiment, the superconducting magnet can be directly wound onto an outer surface of the cavity. Additionally or alternatively, the cavity can serve as a mandrel about which the superconducting magnet is wound.

[0028] The superconducting magnet being directly wound onto the outer surface of the cavity means that the superconducting magnet is in surface contact with the outer surface of the cavity.

[0029] The cavity serving the purpose of a mandrel preferably means that the cavity is a windingaid that facilitates the winding of the superconducting magnet.

[0030] In a second embodiment, the superconducting magnet can be indirectly arranged around the cavity. Additionally or alternatively, at least one insulating element and / or a vacuuminsulation can be arranged between the superconducting magnet and an outer surface of the cavity. Additionally or alternatively, the superconducting magnet and the cavity can be arranged at a distance from one another.

[0031] The superconducting magnet being indirectly arranged around the cavity means that the superconducting magnet is not in surface contact with the outer surface of the cavity but is arranged at a distance from the outer surface of the cavity, wherein a gap is formed. It is particularly preferred that at least one insulating element such as a Styrofoam or a multiplelayer superinsulation and / or a vacuum insulation is arranged or present in the gap formed between the superconducting magnet and the outer surface of the cavity. However, it is likewise conceivable that no insulating element is arranged in said gap but that there is just a vacuum insulation present between the superconducting magnet and the outer surface of the cavity and vice versa. Of course, a vacuum insulation can be present in addition to an insulating element.

[0032] The superconducting magnet being indirectly arranged around the cavity can be in indirect connection with the cavity. That is, an indirect connection between the cavity and the superconducting magnet is conceivable, e.g. via an alignment collar.

[0033] Unless stated otherwise, any explanations made herein regarding the gyrotron system according to the first embodiment likewise apply to the gyrotron system according to the second embodiment and vice versa.

[0034] Hence, the gyrotron system according to both embodiments can further comprise at least one cavity-cooling device that is configured to cool the cavity independently of the superconducting magnet. Additionally or alternatively, the gyrotron system can further comprise at least one superconducting-magnet cooling device that is configured to cool the superconducting magnet independently of the cavity.

[0035] That is, the gyrotron system can employ at least two distinct cooling devices, a cavitycooling device for cooling the cavity and a superconducting-magnet cooling device for cooling the superconducting magnet. As a consequence, a temperature of the superconducting magnet and of the cavity can be the same or different from one another.

[0036] These two distinct cooling devices can be present in addition or in the alternative to the joint cooling device mentioned earlier.

[0037] The superconducting-magnet cooling device can comprise at least one chamber being configured to thermally insulate the superconducting magnet and the cavity from one another and / or being configured to receive at least one cooling fluid, the chamber preferably being a cryostat. Additionally or alternatively, the superconducting-magnet cooling device can be cryogen-free and / or configured to at least one of conductively connect to the superconducting magnet and to dissipate heat from the superconducting magnet.

[0038] That is, the superconducting-magnet cooling device is preferably a chamber such as a cryostat configured to receive the superconducting magnet and to thereby thermally insulate the superconducting magnet from the cavity. Said chamber or cryostat is preferably configured to receive a cooling fluid well-known in the art such liquid nitrogen or liquid helium.

[0039] However, it is likewise conceivable that the superconducting-cooling device can cool the superconducting magnet in a cryogen-free manner. For instance, and as has been outlined above with respect to the joint cooling, the superconducting-cooling device can be configured to conductively connect to the superconducting magnet and to dissipate heat from superconducting magnet. That is, the superconducting-cooling device can comprise at least one heat dissipating element such as a so-called cooling head, for instance in the form of a copper ribbon, that is configured to dissipate heat from the superconducting magnet via thermal conductivity.

[0040] The cavity-cooling device can comprise one or more channels being in connection with or formed in an outer surface of the cavity, and wherein said channels are configured to receive at least one cooling fluid being configured to cool the cavity. Additionally or alternatively, the cavity-cooling device can be cryogen-free and / or configured to at least one of conductively connect to the cavity and to dissipate heat from the cavity.

[0041] That is, the cavity-cooling device can comprise one or more channels that are in connection with the outer surface of the cavity. For instance, the cavity-cooling device can comprise one or more so-called Raschig rings or pieces of tubes that are arranged on the outer surface of the cavity, and wherein the cooling fluid can flow through the Raschig rings or tubes, whereby the cavity is cooled. However, it is likewise conceivable that the channels are an integral part of the cavity, such as formed in the outer surface of the cavity. In any case it is preferred that a cooling of the cavity is achieved by injecting at least one cooling fluid such as water, liquid nitrogen or liquid helium into the channels.

[0042] However, it is likewise conceivable that a cooling of the cavity is achieved without any cooling liquid and in particular cryogen-free, for instance again via a conductive connection of a heat dissipating element such as a cooling head, for instance in the form of a copper ribbon, to the cavity.

[0043] As mentioned initially, the superconducting magnet is configured to exhibit superconductivity when being cooled below its critical temperature. The superconducting magnet preferably comprises or is made of at least one superconducting cable and / or at least one superconducting tape. Additionally or alternatively, the superconducting magnet preferably has the shape of at least one coil, preferably of at least one pancake coil.

[0044] That is, the superconducting magnet can be constructed using a superconducting cable such as a low-temperature superconductor (LTS) and / or a high-temperature superconductor (HTS) cable. Additionally or alternatively, the superconducting magnet can be constructed using a superconducting tape, preferably a low-temperature superconductor (LTS) and / or a high-temperature superconductor (HTS) tape.

[0045] Additionally or alternatively, the superconducting magnet can have the shape of at least one coil, for instance a superconducting cable being wound into a coil or a superconducting tape being wound into a coil. To this end the coil can be a single coil or a multi-coil such as a pancake coil.

[0046] A superconductive magnet such as the superconductive cable or superconductive tape in the form of the coil has a very low electrical resistance, in particular in the order of nanoOhm. Consequently, a high current can be supplied to generate high magnetic fields.

[0047] This high current density contributes to the remarkable compactness that can be achieved with the superconducting magnet according to the invention. Additionally, the superconducting magnet can have a very small inner radius, for instance a few centimeters or a few millimeters, which significantly simplifies magnet fabrication, even for those generating extremely high magnetic fields.

[0048] The superconducting tape or superconducting cable is preferably commercially available and / or well known in the art. For instance, the superconducting tape or superconducting cable can comprise or consist of a high-temperature superconducting material such as a rare earth barium copper oxide (REBCO), for instance GdBaCuO.

[0049] Said superconducting material can be arranged, for instance deposited, on a substrate. The substrate can be non-magnetic and / or mechanically strong and / or corrosion resistant and / or temperature resistant. Additionally or alternatively, the substrate can be an alloy, in particular a nickel alloy such as a nickel alloy further comprising molybdenum, chromium, iron and mixtures thereof.

[0050] Moreover, it is conceivable that the gyrotron system comprises two or more superconducting magnets that are arranged, in particular directly arranged and / or indirectly arranged, around the cavity. Explanations made herein with regard to one superconducting magnet preferably likewise apply to two or more superconducting magnets and vice versa. Two or more superconducting magnets, for instance four superconducting magnets, can be arranged pairwise, i.e. two superconducting magnets behind one another, and opposite each other with respect to a longitudinal direction of the cavity. Other arrangements are of course likewise conceivable.

[0051] The gyrotron system can further comprise at least one magnet configured to generate a magnetic field that adjusts a magnetic field generated by the superconducting magnet. Said magnet is preferably arranged outside of the housing. Said magnet preferably is a normalconducting magnet, i.e., preferably not a superconducting magnet.

[0052] The gyrotron system can further comprise one or more cryo-feedthroughs that connect the superconducting magnet to at least one power source.

[0053] The cryo-feedthroughs preferably are electrical connectors that are configured to transmit electrical currents or power through a cryogenic environment from a power source to the superconducting coils. The cryogenic environment is preferably provided by the joint cooling device and / or the superconducting-magnet cooling device mentioned earlier.

[0054] The power source is preferably arranged outside of the housing.

[0055] The housing preferably is in connection with at least one vacuum pump that is configured to generate a vacuum within the housing.

[0056] Various vacuum pumps are conceivable and are well-known in the art, for instance ion- getter-pumps.

[0057] The vacuum pump is configured to generate a vacuum in the housing being, for instance, in the order of 10'6mbar or lower, such as about 10'9mbar.

[0058] The gyrotron system can further comprise a collector configured to collect a spent electron beam. Additionally or alternatively, the gyrotron system can further comprise at least one output window configured to output the generated electromagnetic radiation from the housing.

[0059] An inner diameter of the superconducting magnet is preferably smaller than an outer diameter of the electron gun and / or smaller than an outer diameter of the collector.

[0060] The gyrotron system can further comprise a launcher configured to transform a transverse electric mode of the electromagnetic radiation generated in the cavity into a Gaussian mode. The launcher preferably is in connection with the cavity and is arranged within the housing. The superconducting magnet is preferably at least partially arranged, in particular at least partially wound around the launcher.

[0061] The launcher and the cavity can be a single-piece element, i.e., the launcher can be considered as an extension of the cavity.

[0062] At least one further superconducting magnet can be arranged, in particular wound directly or indirectly, around the launcher. Such a further superconducting magnet is preferably smaller than the superconducting magnet being arranged around the cavity. Additionally or alternatively, such a further superconducting magnet is preferably configured to adjust a magnetic profile being generated by the superconducting magnet arranged around the cavity.

[0063] As mentioned initially, the gyrotron system comprises an electron gun and a cavity being arranged in the housing.

[0064] Various electron guns are conceivable and are well-known in the art. For instance, the electron gun can be a triode gun. The electron gun produces the electron beam that can be accelerated for instance by a high-voltage DC anode into the cavity.

[0065] The cavity preferably has an elongated shape such as the shape of a cylinder, i.e., the cavity preferably extends along a longitudinal direction. The superconducting magnet being (directly or indirectly) wound around the cavity is preferably arranged coaxially to the cavity and / or at least partially along the longitudinal direction of the cavity and / or at least partially along a radial direction of the cavity.

[0066] The cavity can comprise or consist of at least one metal compound. The cavity can be seen as a resonator in which a high-frequency wave is generated by the resonance coupling of the electron beam performs a cyclotronic motion caused by the magnetic field generated by the superconducting magnet and the high-frequency electromagnetic field of a transverse electric mode of the cylindrical cavity. The electron beam preferably travels through the cavity in a strong axial magnetic field being generated by the superconducting magnet wound around the cavity. In the cavity, a fraction of the transverse part of the electrons' kinetic energy is transformed into a high- frequency beam such as a high-frequency microwave beam as the electron beam resonates with a transverse electric (TE) cavity mode. That is, part of the velocity energy of the electrons is converted into high-frequency energy by a so-called cyclotron resonance maser interaction between the mode of the cavity and the electrons in cyclotron motion caused by the axial magnetic field generated by the superconducting magnet. The thus generated high-frequency beam is converted by the launcher, i.e. a mode converter, where the transverse electric mode is transformed to the fundamental Gaussian mode, and is reflected by mirrors, which direct the converted high-frequency waves towards and through the output window arranged in a wall of the housing, preferably in a sidewall of the housing, and for instance into a microwave waveguide. The electron beam which has undergone the cyclotron resonance maser interaction in the cavity, i.e., the spent electron beam, can be collected by the collector which is configured to absorb the spent electron beam.

[0067] The superconducting magnet and the cavity are preferably assembled together prior to an assembly of the electron gun and collector.

[0068] BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Preferred embodiments of the invention are described in the following with reference to the drawings, which are for the purpose of illustrating the present preferred embodiments of the invention and not for the purpose of limiting the same. In the drawings,

[0070] Fig. 1 shows a schematic longitudinal sectional view through a conventional gyrotron system;

[0071] Fig. 2 shows a schematic longitudinal sectional view through a gyrotron system according to a first embodiment of the invention comprising a housing with all gyrotron subcomponents such as cavity, electron gun, mirror system and collector, and wherein a superconducting magnet is arranged within the same housing of the gyrotron system and is directly wound around the cavity;

[0072] Fig. 3 shows an enlarged view of section A in figure 2;

[0073] Fig. 4 shows a schematic partial sectional view through a gyrotron system according to a second embodiment of the invention comprising a housing, a superconducting magnet and a cavity, wherein the superconducting magnet is arranged within the same housing with the gyrotron system and is indirectly arranged around the cavity.

[0074] DESCRIPTION OF PREFERRED EMBODIMENTS

[0075] A conceptual drawing of a conventional gyrotron system T according to the state-of-the art is depicted in figure 1.

[0076] For the sake of clarity, features of the state-of-the art gyrotron system T are indicated by reference signs with an apostrophe ('), whereas these features are indicated without an apostrophe in the gyrotron system 1 according to the invention.

[0077] Hence, figure 1 depicts a gyrotron system T, wherein an electron beam, generated by thermionic emission in an electron gun 3' such as a magnetron injection gun (MIG), is accelerated by a voltage applied to the body and cathode of the electron gun 3', and is guided by an external magnetic field towards the cavity 5'. In the cavity 5', a fraction of the transverse part of the electrons' kinetic energy is transformed into electromagnetic radiation 16' in the form of microwave energy as the electron beam resonates with a transverse electric (TE) cavity mode. The thus generated high-frequency beam 16' is extracted from the housing 2' through a launcher 13', where the transverse electric mode is transformed to the fundamental Gaussian mode, and a mirror system 14', which guides the high-frequency waves 16' towards an output window 12' arranged in a wall 15' of the housing 2'. The spent electron beam 17', after the interaction in the cavity 5', is guided towards a grounded collector 1 T.

[0078] In this conventional gyrotron system T, the housing 2' and the superconducting magnets 4' are two individual components, wherein the superconducting magnets 4' are arranged outside of the housing 2'.

[0079] In the gyrotron system 1 according to the invention however, the superconducting magnet(s) 4 is arranged within the housing 2 and wound around the cavity 5, see figures 2 to 4.

[0080] To this end, figures 2 and 3 show a first embodiment of the gyrotron system 1 according to the invention, wherein the superconducting magnet 4 is directly wound around the cavity 5, i.e. the superconducting magnet 4 is in surface contact with an outer surface 6 of the cavity 5, and the cavity 5 serves the purpose of a mandrel.

[0081] This is in contrast to the second embodiment of the gyrotron system 1 shown in figure 4, wherein the superconducting magnet 4 is indirectly wound around the cavity 5, i.e. the superconducting magnet 4 is not in surface contact with the outer surface 6 of the cavity 5 but is arranged at a distance d from the cavity 5, wherein a gap 18 is formed between the outer surface 6 of the cavity 5 and the superconducting magnet 4. As furthermore follows from this figure, the launcher 13 and the cavity 5 are a single-piece element, i.e. the launcher 13 is formed on the cavity 5 or can be seen as an extension of the cavity 5, respectively. In the depicted example, an insulating element 7 is arranged between the superconducting 4 magnet and the outer surface 6 of the cavity 5.

[0082] The gyrotron system 1 of both embodiments comprises a housing 2 comprising the electron gun 3, the cavity 5, the launcher 13, several mirrors of the mirror system 14, and the collector 11 , see figure 2. The trajectories of the annular electron beam, which start from the electron gun 3 and end on a collector surface of the collector 11 in an end region of the housing 2, are also indicated.

[0083] The cavity 5 has an elongated shape such as the shape of a cylinder and extends along a longitudinal direction L. The superconducting magnet 4 being directly (see figure 3) or indirectly (see figure 4) wound around the cavity 5 is arranged coaxially to the cavity 5 and extends partially along the longitudinal direction L of the cavity 5.

[0084] The gyrotron system 1 according to the first embodiment comprises a joint cooling device that is configured to jointly cool the superconducting magnet 4 and the cavity 5. Said joint cooling device can comprise a chamber that can receive a cooling fluid as well as at least part of the housing 2 in the region of the cavity 5 and the superconducting magnet 4, whereby the cooling fluid cools the cavity 5 and the superconducting magnet 4 in a joint manner and to a same temperature.

[0085] Figure 4 illustrates another conceivable cooling mechanism, namely, a double-cooling mechanism comprising a cavity-cooling device 8 that is configured to cool the cavity 5 independently of the superconducting magnet 4 and a superconducting-magnet cooling device (not shown in figure 4) that is configured to cool the superconducting magnet 4 independently of the cavity 5. In particular, the superconducting-magnet cooling device comprises at least one chamber such as a cryostat (not depicted) being configured to receive and thermally insulate the superconducting magnet 4 and the cavity 5 from one another and being furthermore configured to receive a cooling fluid, whereby the cooling fluid cools the superconducting magnet 4. The cavity-cooling device 8 comprises here channels 10 being formed in the outer surface 6 of the cavity 5, and wherein said channels 10 are configured to receive at least one cooling fluid being configured to cool the cavity 5. As a consequence, a temperature of the superconducting magnet 4 and of the cavity 5 can be individually controlled.

[0086] LIST OF REFERENCE SIGNS

[0087] 1 gyrotron system

[0088] 2 housing

[0089] 3 electron gun

[0090] 4 superconducting magnet

[0091] 5 cavity

[0092] 6 outer surface of cavity

[0093] 7 insulating element

[0094] 8 cavity-cooling device

[0095] 10 channel

[0096] 11 collector

[0097] 12 output window

[0098] 13 launcher

[0099] 14 mirror system

[0100] 15 wall of housing

[0101] 16 high-frequency microwaves or high-frequency Terahertz waves

[0102] 17 spent electron beam

[0103] 18 gap d distance di inner diameter of superconducting magnet doe outer diameter of electron gun doc outer diameter of collector

[0104] L longitudinal direction of cavity

Claims

CLAIMS1. A gyrotron system (1) comprising:- a housing (2),- an electron gun (3) configured to produce an electron beam,- at least one magnet (4) configured to produce a magnetic field, and- a cavity (5) configured to receive the electron beam, and wherein microwaves and / or Terahertz waves (16) are generatable in the cavity (5) by a resonance coupling between the electron beam and the magnetic field produced by the magnet (4), characterized in that the magnet (4) is a superconducting magnet that is configured to exhibit superconductivity upon cooling below its critical temperature and that is arranged around the cavity (5), and in that the cavity (5) and the superconducting magnet (4) are arranged within the housing (2).

2. The gyrotron system (1) according to claim 1 , wherein the housing (2) forms a common structure that encloses the cavity (5) and the superconducting magnet (4), and / or wherein the housing (2) is monolithic and / or a single-piece element, and / or wherein the cavity (5) and the superconducting magnet (4) are integrated into the housing (2).

3. The gyrotron system (1) according to any one of the preceding claims, wherein the superconducting magnet (4) and the cavity (5) form a common component, and / or wherein the superconducting magnet (4) and the cavity (5) are inseparably and / or non-destructively connected to each other.

4. The gyrotron system (1) according to any one of the preceding claims, wherein the superconducting magnet (4) and the cavity (5) are configured such that they are not independently movable of each other, and / or wherein the superconducting magnet (4) is immovable with respect to the cavity (5), and / or wherein the cavity (5) is immovable with respect to the superconducting magnet (4).

5. The gyrotron system (1) according to any one of the preceding claims, further comprising at least one joint cooling device that is configured to jointly cool thesuperconducting magnet (4) and the cavity (5).

6. The gyrotron system (1) according to claim 5, wherein the joint cooling device is at least one of:- a chamber such as a cryostat configured to receive at least one cooling fluid and / or configured to at least partially receive the housing in the region of the cavity and the superconducting magnet, or- cryogen-free and / or configured to at least one of conductively connect to the cavity and the superconducting magnet and to dissipate heat from the cavity and the superconducting magnet.

7. The gyrotron system (1) according to any one of the preceding claims, wherein the superconducting magnet (4) is directly wound onto an outer surface (6) of the cavity (5), and / or wherein the cavity (5) serves as a mandrel about which the superconducting magnet (4) is wound.

8. The gyrotron system (1) according to any one of claims 1 to 6, wherein the superconducting magnet (4) is indirectly arranged around the cavity (5), and / or wherein at least one insulating element (7) and / or vacuum-insulation is arranged between the superconducting magnet (4) and an outer surface (6) of the cavity (5), and / or wherein the superconducting magnet (4) and the cavity (6) are arranged at a distance (d) from one another.

9. The gyrotron system (1) according to any one of the preceding claims, further comprising at least one cavity-cooling device (8) that is configured to cool the cavity (5), and / or further comprising at least one superconducting-magnet cooling device that is configured to cool the superconducting magnet (4).

10. The gyrotron system (1) according to claim 9, wherein the superconducting-magnet cooling device comprises at least one chamber being configured to thermally insulate the superconducting magnet (4) and the cavity (5) from one another and / or being configured to receive at least one cooling fluid, the chamber preferably being a cryostat, and / or wherein the superconducting-magnet cooling device is cryogen-free and / or configured to at least one of conductively connect to the superconducting magnet (4) andto dissipate heat from the superconducting magnet (4).11 . The gyrotron system (1) according to any one of claims 9 to 10, wherein the cavitycooling device comprises (8) one or more channels (10) being in connection with or formed in an outer surface (6) of the cavity (5), and wherein said channels (10) are configured to receive at least one cooling fluid being configured to cool the cavity (5), and / or wherein the cavity-cooling device (8) is cryogen-free and / or configured to at least one of conductively connect to the cavity (5) and to dissipate heat from the cavity (5).

12. The gyrotron system (1) according to any one of the preceding claims, wherein the superconducting magnet (4) comprises or is made of at least one superconducting cable and / or at least one superconducting tape, and / or wherein the superconducting magnet (4) has the shape of at least one coil, preferably of at least one pancake coil.

13. The gyrotron system (1) according to any one of the preceding claims, further comprising at least one magnet configured to generate a magnetic field that adjusts a magnetic field generated by the superconducting magnet, and wherein said magnet is arranged outside of the housing (2).

14. The gyrotron system (1) according to any one of the preceding claims, further comprising one or more cryo-feedthroughs that connect the superconducting magnet (4) to at least one power source.

15. The gyrotron system (1) according to any one of the preceding claims, wherein the housing (2) is in connection with at least one vacuum pump that is configured to generate a vacuum within the housing (2).

16. The gyrotron system (1) according to any one of the preceding claims, further comprising at least one of:- a collector (11) configured to collect a spent electron beam (17), or- an output window (12) configured to output the generated electromagnetic radiation (16) from the housing (2).

17. The gyrotron system (1) according to any one of the preceding claims, wherein an inner diameter (di) of the superconducting magnet (4) is smaller than an outer diameter(doe) of the electron gun (3) and / or an outer diameter (doc) of the collector (11).

18. The gyrotron system (1) according to any one of the preceding claims, wherein the gyrotron system (1) further comprises a launcher (13) configured to transform a transverse electric mode of the electromagnetic radiation generated in the cavity (5) into a Gaussian mode, wherein the launcher (13) is in connection with the cavity (5) and is arranged within the housing (2), and wherein at least one further superconducting magnet (4) is at least partially arranged around the launcher (13).

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