XeCl激光诱发SF_6气体击穿及高压开关触发特性的研究

给出了ＸｅＣｌ激光（３０８ｎｍ）诱发ＳＦ＿６气体击穿及高压开关触发特性的研究结果。ＳＦ＿６气体击穿所需要的ＸｅＣｌ激光的功率密度很强地随气体压强而变。在ＳＦ＿６气体压强为０．０２ＭＰａ时，击穿功率密度为４．６ＧＷ／ｃｍ￣２，当压强为０．０４８ＭＰａ时，击穿阈值达最小值为３．２ＧＷ／ｃｍ￣２，而在高气压情况（气压大于０．０２ＭＰａ），其所需功率密度趋于饱和为４ＧＷ／ｃｍ￣２。采用激光触发间隙开关系统（ＬＴＧＳ），获得良好ＳＦ＿６气体开关触发特性：对自击穿电压Ｖ＿（ａｂ）≈６０ｋＶ的小型开关，在充电电压为Ｖ＿（ｃｈ）＝０．９６Ｖ＿（ａｂ）时，得开关延迟时间ｔ＿ｄ≈２０ｎｓ，抖动时间σ≈２６０ｐｓ。

Laser-induced breakdown spectroscopy characterization of Al in different matrix

Some experimental investigations were carried out with the samples of metal Al and AlCl3 solutions. It is found that the spectrum varies with the change of experimental setup parameters both in Al bulk material and AlCl3 solutions. The temporal evolution properties and the affection of incident laser energy on the laser-induced breakdown spectroscopy (LIBS) signals were also discussed. The lifetime of laser induced plasma in AlCl3 solutions is found to be about 30 ns which is much shorter than in solid materials. Compared with the solid samples, the Al LIBS signals in AlCl3 solutions require higher laser energy. Under the optimized conditions, the detection limit of Al in AlCl3 solution was determined to be around 1000 ppm for the system we used.