收集极释气对相对论返波管影响的粒子模拟  

Particle-in-cell simulation on effect of collector outgassing on relativistic backward oscillator

作　　者：王洪广[1,2] 柳鹏飞 张建威 李永东[1,2] 曹亦兵[3] 孙钧[3] Wang Hong-Guang;Liu Peng-Fei;Zhang Jian-Wei;Li Yong-Dong;Cao Yi-Bing;Sun Jun(Key Laboratory for Physical Electronics and Devices of Ministry of Education, Xi’an Jiaotong University, Xi’an 710049, China;School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China;Northwest Institute of Nuclear Technology, Xi'an 710024, China)

机构地区：[1]西安交通大学,电子物理与器件教育部重点实验室,西安710049 [2]西安交通大学电子科学与工程学院,西安710049 [3]西北核技术研究所,西安710024

出　　处：《物理学报》2019年第18期184-190,共7页Acta Physica Sinica

基　　金：国家自然科学基金委员会与中国工程物理研究院联合基金(批准号:U1530133);陕西省自然基金面上项目(批准号:2018JM6062)资助的课题~~

摘　　要：相对论返波管被认为是最具有应用潜力的高功率微波器件之一.随着输出微波功率的进一步提高,相对论返波管内部包括收集极处的击穿现象越来越严重,最终导致脉冲缩短,成为器件向高功率、高能量方向发展中的最大障碍,也是目前制约其发展的重要问题之一.本文基于自主研发的2.5 维粒子模拟软件UNIPIC-2D,采用动态释气模型研究了不同释气系数下相对论返波管收集极释气与电离过程及引导磁场的影响.粒子模拟结果表明,随着电子不断轰击收集极,收集极表面气压升高,并发生气体电离,产生的等离子体沿引导磁场进入慢波结构区域,影响束-波相互作用过程,使得输出功率下降;随着释气系数的增大,脉冲缩短现象越来越明显;在低引导磁场情况下,击穿以及脉冲缩短现象得到一定的缓解.The relativistic backward-wave oscillator has been considered to be one of the most promising high-power microwave devices. As the output microwave power is further increased, the breakdown phenomenon inside the relativistic backward-wave oscillator, including the collector pole, becomes more and more serious, which eventually leads to the pulse shortening, becoming a biggest obstacle to the development of the device with high power and high energy. Such a problem has also been one of the important issues which constrain its development. Based on the 2.5D particle-in-cell simulation software, i.e. UNIPIC-2D developed by our research group, in this paper the dynamic gassing model is used to study the effects of the relativistic backward-wave oscillator collector breakdown process and the guiding magnetic field under different outgassing coefficients. The result of particle simulation demonstrates that as the electrons continue to bombard the collector, the surface pressure of the collector is increased, and gas ionization occurs. The generated plasma enters into the slow-wave structure along the guiding magnetic field, thus affecting the beam-wave interaction process and causing the output power to drop. With the increase of the gas release coefficient, the pulse shortening phenomenon becomes more and more obvious. In the case of low guiding magnetic field, the breakdown and pulse shortening are alleviated.

关 键 词：相对论返波管 收集极 脉冲缩短 击穿 

分 类 号：TN125[电子电信—物理电子学]