光学 精密工程, 2011, 19 (2): 273, 网络出版: 2011-03-30
超高功率体放电的形成及其应用
Formation of superpower volume discharges and their applications
体放电 扩散放电 非均匀电场 逃逸电子 紫外激光器 修饰及清洁 volume discharge diffuse discharge non-uniform electric field runaway electrons UV laser modification and cleaning
摘要
研究了氮气中的高压体(扩散)放电特性,实验中施加的极间隙脉冲电压达数百千伏,持续时间为数纳秒,上升时间为几个纳秒,给出了实验结果。研究了氦气压强为(0.4~2)×105 Pa时,从扩散形式到火花放电的放电转换过程。确定了在氮气压强下电流幅度与逃逸电子束电流脉宽的关系。结果表明,导致隙间扩散放电的超短雪崩电子束(SAEB)对放电过程有重要的影响。在该压强下得出了SAEB瞬间产生相对放电电流的时延与压强的关系,根据该关系,时延随着压强增加而变化,并且在压强为2×105 Pa时最小,同时扩散放电电流脉冲的峰值随压强增加而减小。在0.5×105 Pa的压强下,使用刀片电极和6 cm长的N2∶SF6=10∶1的激活媒质,得到了输出能量为2 mJ、脉冲功率为0.55 MW的激光。最后,在大气压强下,对AlBe箔片进行了重复频率放电处理(REP),其表层清除了碳而且氧原子以450 nm/300 pulse渗入箔片。
Abstract
The experimental results on study of characteristics of the high-pressure volume (diffuse) discharges in nitrogen at applying to the interelectrode gap voltage pulse with the amplitude of hundreds kV, duration of several ns and the rise-time of fraction ns are presented. At the pressure range of nitrogen in (0.2-4)×105 Pa, the discharge transformation from the diffuse form to the spark is investigated. Dependencies of the current amplitude and FWHM of the runaway electron beam current on nitrogen pressure are determined. It is shown that the generation of the Supershort Avalanche Electron Beam (SAEB) leading to the formation of diffuse discharge in the gap has a significant influence on the development of the discharge. At the pressures indicated above, the dependence of the time delay of SAEB’s moment generating relatively discharge current beginning on pressure are obtained. According to this dependence, the time delay changes as pressure increases and it is minimal at pressure of 2×105 Pa. Also, it is shown that the maximum peak value of diffuse discharge current pulse decreases with increasing pressure. At a pressure of 0.5×105 Pa with the use of blade electrodes and the N2∶SF6=10∶1 active medium of length 6 cm, the output laser energy of 2 mJ is achieved for the pulse power of 0.55 MW. It is reported that during the treatment of the AlBe foil by the Runaway Electron Preionized(REP) discharge in atmospheric pressure air, its surface layer is cleaned from carbon, and atoms of oxygen penetrate into the foil (by 450 nm per 300 pulses).
TARASENKO V F, BAKSHT E KH, BURACHENKO A G, LOMAEV M I, RYBKA D V, SHULEPOV M A, SOROKIN D A, SHUT'KO V. 超高功率体放电的形成及其应用[J]. 光学 精密工程, 2011, 19(2): 273. TARASENKO V F, BAKSHT E KH, BURACHENKO A G, LOMAEV M I, RYBKA D V, SHULEPOV M A, SOROKIN D A, SHUT'KO V. Formation of superpower volume discharges and their applications[J]. Optics and Precision Engineering, 2011, 19(2): 273.