Double-anode Magnetron Injection Gun Research Articles

Design and simulation of a W-band gyrotron traveling wave amplifier

The design of a W-band gyrotron traveling wave tube amplifier is presented. The device with a lossy ceramic interaction circuit operates in the fundamental harmonic TE01 circular electric mode. The 70-kV, 6-A electron beam is produced by a double anode magnetron injection gun with an average perpendicular-to-parallel velocity ratio of 1.2 and a parallel velocity spread of less than 3%. The beam-wave interaction is investigated by using a particle-in-cell code. The simulations predict that the amplifier can produce an output peak power of over 100 kW, 28% efficiency, 42 dB gain, and a 3 GHz bandwidth, respectively under the assumption of beam velocity spread 3%.

Design and Simulation Analysis of a Magnetron Injection Gun for a 0.42 THz Second Harmonic Gyrotron

A double anode magnetron injection gun (MIG) for a 0.42 THz second harmonic gyrotron has been presented in this paper. Through design, simulation and optimization by the particle-in-cell code, a double-anode electron gun with maximum transverse velocity spread of 3.19 % is obtained, the beam acceleration voltage is 50 kV, operating current is 5.5 A and the ratio of the transverse velocity to the axial velocity is equal to 1.4. A comprehensive analysis of MIG for 0.42 THz second harmonic gyrotron is presented, and the designed electron gun well satisfies the requirement of the 0.42 THz gyrotron.

Design of a double-anode magnetron-injection gun for the W-band gyrotron

A double-anode magnetron-injection gun (MIG) was designed. The MIG is for a W-band 10-kW gyrotron. Analytic equations based on adiabatic theory and angular momentum conservation were used to examine the initial design parameters such as the cathode angle, and the radius of the beam emitting surface. The MIG’s performances were predicted by using an electron trajectory code, the EGUN code. The beam spread of the axial velocity, Δvz/vz, obtained from the EGUN code was observed to be 1.34% at α = 1.3. The cathode edge emission and the thermal effect were modeled. The cathode edge emission was found to have a major effect on the velocity spread. The electron beam’s quality was significantly improved by affixing non-emissive cylinders to the cathode.

Double-beam magnetron injection gun

A double-beam magnetron injection gun was used to improve the output power of gyrotrons. A double-beam magnetron injection gun can output two relativistic electron beams, which is a better way to raise the current of the magnetron injection gun without reducing the quality of electron beams. Compared with the double-anode magnetron injection gun with the same output current, the double-beam magnetron injection gun can reduce velocity spread and improve the quality of electron beams, because of its smaller influence of the space charge. Using the software MAGIC, a double-beam magnetron injection gun with a modest velocity ratio and a low velocity spread of electron beams was designed.

全三维55GHz双阳极磁控注入式电子枪数值模拟

The initial design of magnetron injection gun was analyzed based on the theory of the adiabatic compression and conservation of angular momentum. A series of initial parameters of 55 GHz double anode magnetron injection gun were obtained by Matlab programming. Independent research and development of three-dimensional particle simulation software CHIPIC was used to carry out numerical simulation. The obtained simulation data were analyzed and optimized. High-performance electron beam was obtained with a ratio of transverse velocity to axial velocity of 1.44 and a maximum velocity spread of 5.8%. The beam could meet the requirements of 55 GHz gyrotron oscillator tube.

A W-band four-cavity gyroklystron amplifier

介绍了W波段四腔回旋速调管放大器的设计.放大器工作在基膜TE01圆电模式，电子束工作电压70 kV，工作电流6 A，设计的双阳极磁控式注入电子枪，电子束纵横速度比1.5，速度零散小于4%.采用粒子模拟方法分析了各种参数对器件性能的影响.模拟结果显示，设计的放大器在电子束速度零散4%的情况下，增益35 dB，带宽800 MHz，输出功率100 kW，效率为23.8%.;The design of a W-band four-cavity gyroklystron amplifier is presented. The device operates in the fundamental harmonic TE01 circular electric mode. The 70 kV, 6 A beam is produced by a double anode magnetron injection gun (MIG) with an average perpendicular-to-parallel velocity ratio of 1.5 and a parallel velocity spread of less than 4%. Particle-in-cell (PIC) simulations have been performed to predict general RF performance for various parameters. The simulated results show that the designed gyroklystron amplifier can produce about 35 dB gain, 800 MHz bandwidth and 100 kW peak output power with power conversion efficiency of 23.8% for a beam with 4% axial velocity spread.

双阳极回旋管磁控注入电子枪设计

双阳极回旋管磁控注入电子枪设计

Analysis and design of a double-anode magnetron injection gun for 1THz gyrotron

Based on the electron optics theory, through a massive numerical calculation by programming, a double-anode magnetron injection gun (MIG) for a 1THz gyrotron is designed. The method of calculation and design of MIG is expounded, and the problem that high magnetic compression ratio in THz gyrotron(compression ratio of 125 in electron gun for 1THz gyrotron in this paper)could lead to the reversal of direction of electron flow is also detailedly analyzed and simulated. Through simulation and optimization, an MIG with a modest velocity ratio of the beam (=1.3) and a low velocity spread (8%) is designed.

170 GHz回旋管大束流双阳极磁控注入电子枪的分析及设计

170 GHz回旋管大束流双阳极磁控注入电子枪的分析及设计

Numerical Simulation of a Double-anode Magnetron Injection Gun for 110 GHz, 1 MW Gyrotron

A 40 A double-anode magnetron injection gun for a 1 MW, 110 GHz gyrotron has been designed. The preliminary design has been obtained by using some trade-off equations. The electron beam analysis has been performed by using the commercially available code EGUN and the in-house developed code MIGANS. The operating mode of the gyrotron is TE22,6 and it is operated in the fundamental harmonic. The electron beam with a low transverse velocity spread (\( \delta {\beta_{ \bot \max }} = 2.26\% \)) and the transverse-to-axial velocity ratio of the electron beam (α) = 1.37 is obtained. The simulated results of the MIG obtained with the EGUN code have been validated with another trajectory code TRAK. The results on the design output parameters obtained by both the codes are in good agreement. The sensitivity analysis has been carried out by changing the different gun parameters to decide the fabrication tolerance.

Design of a Ka-band gyro-TWT for radar applications

The design of a Ka-band gyrotron traveling wave tube (TWT) amplifier capable of operating over a wide range of peak powers and bandwidths is presented. The amplifier operates in the TE/sub 11/ mode at the fundamental cyclotron harmonic. Instantaneous bandwidths in the range of 2.5 to 3.9 GHz (at 1 dB below saturation) with corresponding peak powers between 92.2 and 57.9 kW can be achieved by simply adjusting the mod-anode voltage of the electron gun. The corresponding gains range from 57.1 to 36.0 dB. The design performance is obtained with a high quality, 6 A, 70 kV electron beam generated with a double-anode magnetron injection gun. This wide range performance capability in the design is achieved via the use of the distributed loss approach in the interacting circuit, which also guarantees zero-drive stability. A diffractive loading scheme is employed in the lossy section of the circuit to ensure high average power operation of the amplifier.

Design of a 34-GHz second-harmonic coaxial gyroklystron experiment for accelerator applications

Presents the complete design of a 34-GHz, four-cavity coaxial gyroklystron experiment. The 500-kV, 300-A beam is produced by a double anode magnetron injection gun (MIGc) with an average perpendicular-to-parallel velocity ratio of 1.5 and a parallel velocity spread of less than 5%. The microwave circuit has a first-harmonic TE/sub 011/ input cavity that is driven at 17.135 GHz. It has buncher, penultimate, and output cavities that operate In the TE/sub 021/-mode and are resonant near the second harmonic of the gyrofrequency. A peak power of 55 MW is obtained with a 47-46 gain and 36.5% efficiency. A complete description of the system is presented. We also present scaled circuit designs at 17 GHz and 91 GHz.

A mechanically tunable magnetron injection gun

The magnetron injection gun (MIG) has been the predominant choice as the electron-beam generator in gyrodevices and it can be tuned by externally installed magnetic-field trim coils. The double-anode MIG, traditionally employed in most experiments, has the intermediate anode as an internal tuning mechanism. The single-anode design, on the other hand, is simpler to construct but lacks an internal beam tuning mechanism. The current paper describes a method to allow mechanical tuning of the MIG. Since the tip of the cathode is located in the region of the highest electric-field gradient, its extension and retraction relative to the rest of the cathode assembly provide an effective means for local electric-field profile modification and, therefore, a tuning mechanism for the electron-beam property and quality. It is demonstrated, in computer simulations and experimental tests, that the tuning mechanism adds a useful degree of freedom to the single-anode MIG for beam optimization. This method may also be applied to the double-anode design.