CAJ | 학술논문

当注入功率较高时,大间隙速调管输入腔的基频电流分布中,除常规意义上的最佳群聚电流峰值(第一峰值电流)外,出现了与第一峰值电流幅值相当的第二峰值电流.结合群聚理论和粒子模拟结果,研究和讨论了第二峰值电流产生的机理.研究结果表明,第二峰值电流的出现由高电压调制系数下出现的多重电子超越效应造成.当二极管电压600 kV,束流5 kA,工作频率3.6 GHz时,利用多重超越效应可在保持最佳群聚距离基本不变的前提下,把大间隙速调管的束流群聚深度由80%提高到92%,群聚束流的基频功率也从2.2 GW提高到2.8 GW,增幅约27%.
당주입공솔교고시,대간극속조관수입강적기빈전류분포중,제상규의의상적최가군취전류봉치(제일봉치전류)외,출현료여제일봉치전류폭치상당적제이봉치전류.결합군취이론화입자모의결과,연구화토론료제이봉치전유산생적궤리.연구결과표명,제이봉치전류적출현유고전압조제계수하출현적다중전자초월효응조성.당이겁관전압600 kV,속류5 kA,공작빈솔3.6 GHz시,이용다중초월효응가재보지최가군취거리기본불변적전제하,파대간극속조관적속류군취심도유80%제고도92%,군취속류적기빈공솔야종2.2 GW제고도2.8 GW,증폭약27%.
Under the high power injection condition of the wide-gap klystron amplifier (WKA), a second peak current appears besides the conventional optimally bunching current (or the first peak current) in the distribution of the fundamental integral current. Considering the electron bunching theory and the Particle-in-cell (PIC) simulation results together, the formation mechanism of the second peak current is discussed. The results indicate that the second peak current has a close relation with the electron multiple-overtaking phenomenon in the case of high voltage modulation coefficient. When the diode voltage is 600 kV, beam current is 5 kA and working frequency is 3.6 GHz, the beam modulation depth of the WKA is enhanced to 92%from 80%according to the multiple-overtaking mechanism. Simultaneously, the bunching current power is improved from 2.2 GW to 2.8 GW, and a 27 percent increment is obtained.