Rai Virendra N, Zhang Hansheng, Yueh Fang Y, Singh Jagdish P, Kumar Akshaya
Diagnostics Instrumentation and Analysis Laboratory, Mississippi State University, 205 Research Boulevard, Starkville, Mississippi 39759-7704, USA.
Appl Opt. 2003 Jun 20;42(18):3662-9. doi: 10.1364/ao.42.003662.
Effects of a steady magnetic field on the laser-induced breakdown spectroscopy of certain elements (Mn, Mg, Cr, and Ti) in aqueous solution were studied, in which the plasma plume expanded across an external steady magnetic field (approximately 6 kilogauss). Nearly 1.6 times enhancement in the line emission intensity was observed in the presence of the magnetic field. The temporal evolution of the line emission showed a significant enhancement in plasma emission between 2- and 7- micro(s) gate delays for Mg in the presence of the magnetic field (5-30 micro(s) for Mn). This enhancement in the emission is attributed to an increase in the rate of recombination because of an increase in plasma density due to a magnetic confinement after cooling the plasma. The increase in the optical line emission due to magnetic confinement was absent when the plasma was hot with a dominant background (continuum) emission. The limits of detection of Mg and Mn were reduced by a factor of two in the presence of a steady magnetic field of 5 kilogauss.
研究了稳恒磁场对水溶液中某些元素（锰、镁、铬和钛）激光诱导击穿光谱的影响，其中等离子体羽流在外部稳恒磁场（约6千高斯）中扩展。在磁场存在的情况下，观察到谱线发射强度增强了近1.6倍。对于镁，在磁场存在时，谱线发射的时间演化显示在2至7微秒的选通延迟之间等离子体发射有显著增强（对于锰为5至30微秒）。这种发射增强归因于在等离子体冷却后由于磁约束导致等离子体密度增加，从而使复合率提高。当等离子体处于高温且具有占主导地位的背景（连续谱）发射时，不存在因磁约束导致的光学谱线发射增加。在5千高斯的稳恒磁场存在时，镁和锰的检测限降低了一半。
