共查询到20条相似文献,搜索用时 46 毫秒
1.
Nusinovich G.S. Read M.E. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1999,27(2):355-362
The scaling of operating parameters and the tendencies in the efficiency of the step-tunable gyrotron operating in a set of modes in a cavity of a given length are considered. Results of calculations are reported for the design of a ~1-kW, step-tunable gyrotron oscillator operating from 150 to 600 GHz in steps of about 15 GHz. Detailed results are presented for the efficiency, power losses in the cavity, and the starting conditions. Designs of the electron gun electrodes and of an output mode transducer are also presented. Full modulation of the radiation via the modulating anode of a magnetron injection gun is considered. The gyrotron would be of use for plasma diagnostics and spectroscopy, including electron paramagnetic resonance spectroscopy (EPR) 相似文献
2.
Pereyaslavets M. Idehara T. Nishida N. Yoshida K. Ogawa I. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1999,27(2):363-367
Frequency modulation of the gyrotron output has been numerically simulated employing the approximation of weakly relativistic, mono-velocity electron beam as well as a quasi-empirical approach. The simulation results are compared to a first experiment in the 300 GHz region performed with a submillimeter-wave gyrotron named “Gyrotron FU IV”. The modulation amplitude of 30 MHz has been achieved by a 120 V modulation of the accelerating voltage resulting in the variation of the relativistic electron mass and in the corresponding modulation of the electron cyclotron frequency. Calculated amplitudes of frequency modulation are in reasonable agreement with the experimental results 相似文献
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ZENG Jianer RAO Jun KANG Zhihua LI Bo WANG Mingwei LU Zhihong ZHOU Jun HUANG Mei FENG Kun 《核工业西南物理研究院年报(英文版)》2006,(1):76-78
In the last year, ECRH system has been built in the HL-2A and the testing of gyrotron is also finished. In the project testing, one of the problems is current-peak occurring in the anode circuit of gyrotron. The current-peak is much larger than that of the value set in protection circuit. The frequent current-peak frequently occurring in the rising of anode-voltage often caused the protection circuit to mistaken trigger. The mistaken triggering often halted the normal gyrotron-testing. A set of equations of anode circuit are derived for analysis the phenomena of the current-peak. The calculation based on the deduced formula shows that value of the current-peak strongly depends on the inductance L, capacitance C and the ramp-time of anode voltage in the anode circuit. The conductance L and capacitance C are the characteristic inductance and capacitance of the cable that is used for anode HV power supply. The numerical calculation is exactly consistent with waveform of the current peak recorded by oscillograph, that means the derived formula are correct. In order to decrease the value of the current-peak, we should decrease capacitance C, and increase inductance L and ramp-time of anode voltage. 相似文献
5.
La Agusu T. Idehara H. Mori T. Saito I. Ogawa S. Mitsudo 《International Journal of Infrared and Millimeter Waves》2007,28(5):315-328
Design of a CW 1 THz gyrotron at second harmonic operation using a 20 T superconducting magnet has been described. The mode
competition analysis is employed to investigate operation conditions of second harmonic mode, which is being excited at the
frequency ranging from 920 GHz to 1014 GHz. The output power up to 250 watt corresponding to the efficiency of 4.16 percent
could be achieved by using an electron beam with accelerating voltage 30 kV and current 200 mA. The important advantage of
this gyrotron is that the single mode excitation at second harmonic, and extremely high frequency of the radiation, could
be maintained even at high currents. It opens possibility to realize a high power radiation source at 1 THz. Such gyrotron
is under construction at FIR Center, University of Fukui. 相似文献
6.
Response of a gyrotron to small-amplitude low-frequency-modulated microwaves reflected from a plasma
G. M. Batanov L. V. Kolik Yu. V. Novozhilova M. I. Petelin A. E. Petrov K. A. Sarksyan N. N. Skvortsova N. K. Kharchev 《Technical Physics》2001,46(5):595-600
Experiments in the L-2M stellarator revealed the intense noise modulation of the gyrotron power and the change in its mean value under the action of the noise modulation of radiation reflected from the plasma column. The effect observed is explained in terms of the resonant locking of the gyrotron self-oscillations due to wave reflection from the fluctuating plasma load. 相似文献
7.
根据220 GHz回旋管的工作要求,设计了其所需的脉冲磁场系统与电子枪。脉冲磁场系统采用哑铃状结构,具有均匀区长、电阻小与电感小等优点,可以在较低电容与电压下获得更高的脉冲峰值磁场,并分析了其脉冲放电特性。电子枪采用双阳极磁控注入枪,用EGUN对其进行了设计优化,电子注纵横速度比为1.53,速度零散为3.1%。实验研究表明,脉冲磁场峰值强度达到8 T,电子注电流达到2 A,电子电流基本传输到靶片,控制极与阳极没有截获到电子,脉冲磁场系统与电子枪工作正常,达到设计要求。 相似文献
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V. A. Flyagin V. I. Khizhnyak V. N. Manuilov M. A. Moiseev A. B. Pavelyev V. E. Zapevalov N. A. Zavolsky 《International Journal of Infrared and Millimeter Waves》2003,24(1):1-17
Main results of experimental testing of the 140 GHz/1.5 MW coaxial gyrotron are summarized. High selective properties of the coaxial cavities and a possibility to increase considerably the efficiency of a coaxial gyrotron only by applying independently an appropriate voltage on its electrodes (without any design modification) have been confirmed. Successful uses of the two-potential connection scheme for the frequency step tuning and output power modulation in a coaxial gyrotron has been also demonstrated. 相似文献
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为了打破传统单注回旋管只能产生较低功率的局限性, 本文基于自主研发的PIC粒子模拟软件CHIPIC 对110 GHz和220 GHz同轴腔双注回旋管进行全三维数值模拟研究. 在理论分析同轴双电子注电子枪设计模型和初始参数的基础上通过CHIPIC对其进行优化设计, 得到了具有横纵速度比为1.0, 最大速度零散约为5.4%的高性能电子束; 并将此优化后的双阳极双注电子枪取代传统回旋管数值模拟时采用的回旋 发射进行110 GHz和220 GHz双注回旋管整管的数值模拟, 并采用MPI四进程并行计算, 最终获得了具有双频分别为110 GHz和220 GHz、模式为TE02模、平均输出功率约在70 kW、 效率达到8.75%的高性能双注回旋振荡管.
关键词:
同轴腔双注回旋管
同轴双电子注电子枪
横纵速度比
速度零散 相似文献
11.
HL-2A装置3MW ECRH系统采用双高压电源形式的电子回旋管,阴极高压电源为回旋管提供加速束电流,阳极高压电源对通过转换区后的束电流施加减速作用,利于回旋管收集极吸收。根据回旋管运行特点和各回旋管不同的工作特性,合理优化回旋管阴极、阳极高压电源工作电压和其他参数。通过远程监控系统,使同时工作的回旋管处于较好的工作状态,充分提高HL-2A装置ECRH系统多管运行的微波输出功率。实验中,6支回旋管同时运行时,微波最高输出功率2.5MW,达到设计额定值83%,使HL-2A装置中等离子体得到了有效的加热。 相似文献
12.
HL-2A装置3MW ECRH系统采用双高压电源形式的电子回旋管,阴极高压电源为回旋管提供加速束电流,阳极高压电源对通过转换区后的束电流施加减速作用,利于回旋管收集极吸收。根据回旋管运行特点和各回旋管不同的工作特性,合理优化回旋管阴极、阳极高压电源工作电压和其他参数。通过远程监控系统,使同时工作的回旋管处于较好的工作状态,充分提高 HL-2A 装置 ECRH 系统多管运行的微波输出功率。实验中,6支回旋管同时运行时,微波最高输出功率2.5MW,达到设计额定值83%,使HL-2A装置中等离子体得到了有效的加热。 相似文献
13.
Dumbrajs O. Nuisnovich G.S. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1992,20(4):452-457
A theory is presented which describes the dependence of the multimode operation of a gyrotron on the modulation and beam voltages. Nonlinear nonstationary processes are considered. An approximate start-up scenario of a gyrotron is determined which makes it possible to achieve single-mode excitation and high-efficiency operation in a desired mode, as well as to switch the tube to a similar operation in other modes 相似文献
14.
《中国物理C(英文版)》2015,(10)
For MWPCs used for X-ray position detection, simulation studies of the anode wire modulation effect of the detector were carried out using the Garfield program. Different gas mixtures were used as the working gas in the simulation, so as to obtain the influence of the X-ray cross section and electron diffusion coefficient of the working gases on the anode wire modulation effect of an MWPC with anode wire spacing of 2 mm. Results show that, though a working gas with higher X-ray cross section implies a larger average drift distance for the ionized electrons, such gas mixtures are of little use in improving the anode wire modulation effect of MWPCs. It is found that the transverse electron diffusion coefficient is the determining factor for the extent of the anode wire modulation effect in the detector. 相似文献
15.
Ronald K. Cross A.W. Phelps A.D.R. Wenlong He Huabi Yin Spark S.N. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1998,26(3):375-382
Experiments have investigated the behavior of explosive emission cathode gyrotrons using cylindrically symmetric coaxial diodes with centrally located knife-edged cathode and conical anode. Voltage probes and current shunts were exploited to monitor the diode electrical behavior when driven by a 3 μs 1/e time Marx power supply (up to 150 kV). Temporal reference signals permitted comparison of the diode's electrical evolution with the simultaneously measured microwave output signal from the gyrotron. The microwave output pulse duration was found to depend on the diode gap spacing (in the range 16-27 mm), the cavity magnetic field (range 1.3-3.3 T) and the cathode material, the termination being caused by the decay of the accelerating potential across the diode and the disruption of the diode geometry. The ratios of the cathode flare expansion velocities for graphite, copper and stainless steel cathodes were estimated as (1:(1.3±0.2):(2.2±0.5)) with a corresponding change in the duration of the microwave output signal [((590±17):(414±25):(325±10)) ns at 2.6 T]. Preliminary results are reported of recent experiments which have compared the optical emissions from the diode region during pulsed gyrotron operation with the simultaneously recorded diode electrical behavior and the gyrotron microwave output 相似文献
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Udaybir Singh Nitin KumarNarendra Kumar Anil KumarA.K. Sinha 《Infrared Physics & Technology》2012,55(1):108-111
In this paper, the three-dimensional simulation of triode-type magnetron injection gun (MIG) for 120 GHz, 1 MW gyrotron is presented. The operating voltages of the modulating anode and the accelerating anode are 57 kV and 80 kV respectively. The high order TE22,6 mode is selected as the operating mode and the electron beam is launched at the first radial maxima for the fundamental beam-mode operation. The initial design is obtained by using the in-house developed code MIGSYN. The numerical simulation is performed by using the commercially available code CST-Particle Studio (PS). The simulated results of MIG obtained by using CST-PS are validated with other simulation codes EGUN and TRAK, respectively. The results on the design output parameters obtained by using these three codes are found to be in close agreement. 相似文献
18.
High-frequency gyrotron operation in the TE611 whispering gallery mode is reported. Powers as high as 112 kW and an efficiency as high as 25.4 percent have been obtained. In addition to the TE611 mode, ten other fundamental modes with frequencies between 133.9 and 216.4 GHz were observed. A quasi-optical antenna for whispering gallery modes has been tested for the TE611 mode. The combination of this antenna and a reflector produces a well-collimated linearly polarized RF beam suitable for electron cyclotron resonance heating (ECRH) or plasma diagnostics. The experimental conversion efficiency was determined to be 89 percent, and the cross polarization was down by 25 dB. A new quasi-optical transmission line employing this antenna has also been tested with the gyrotron. The absence of mode competition for the TE611 mode, as well as the efficient conversion of the output radiation into a linearly polarized Gaussian-like beam, substantiates the arguments for operation in surface modes in high-power gyrotrons. The implications of quasi-optical antennas for megawatt gyrotron window design are discussed. 相似文献
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E. Borie 《International Journal of Infrared and Millimeter Waves》2003,24(4):419-427
The modulation of the output power of a 140 GHz gyrotron for fusion plasma heating at the W7-X Stellarator is simulated numerically. It is shown that for appropriate beam properties, power modulation is possible. The output power shows almost no dependence on whether the accelerating voltage is being increased or decreased. 相似文献
20.
La Agusu T. Idehara I. Ogawa T. Saito T. Kanemaki H. Takahashi T. Fujiwara 《International Journal of Infrared and Millimeter Waves》2007,28(7):499-511
A CW gyrotron for the sensitivity enhancement of NMR spectroscopy through dynamic nuclear polarization has been designed.
The gyrotron operates at the second harmonic and frequency of 394.6 GHz with the main operating mode TE0,6. Operating conditions of other neighboring cavity modes such as TE2,6 at frequency of 392.6 GHz and TE2,3 at frequency of 200.7 GHz were also considered. The experimental conditions of the gyrotron at low and high voltages are
simulated. The output power of 56 watts corresponds to the efficiency of 2 percent at low voltage operation and frequency
of 394.6 GHz is expected. 相似文献