期刊
SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY
卷 58, 期 2-3, 页码 185-209出版社
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/S0584-8547(02)00255-0
关键词
pulsed glow discharge; argon; nitrogen; ionizing plasma; recombining plasma; metastable quenching; excitation/ionization processes; glow discharge mass spectrometry
类别
The addition of N-2 to a millisecond-pulsed glow discharge (PGD) allows diagnostic measurements of the PGD but is found to drastically influence the transient signals arising from the argon and sputtered analyte atoms. Penning excitation between metastable argon atoms and ground state nitrogen molecules and charge transfer between argon ions and the added nitrogen reduce the degree of ionization of sputtered atoms during the power-on, plateau, period by a factor of similar to10 (at 1% N-2 by vol.). The added nitrogen affects sputtered atom emission signals less at this time because electron excitation dominates the excitation of these species. Upon power termination, afterpeak, the added nitrogen prevents plasma recombination in two major mechanisms: (i) the nitrogen reduces the number of argon ions available for recombination in the afterpeak; and (ii) vibrationally excited states of nitrogen slow the thermalization of electrons thereby decreasing recombination efficiency. The argon: ion population contributes significantly to the afterpeak increase in the number of metastable argon atoms. These atoms are essential for the afterpeak ionization of sputtered atoms. Judicious selection of the nitrogen partial pressure can tune the delay time of afterpeak ionization/recombination by up to 200 mus. This could be particularly beneficial for time-resolved optical or mass spectrometric analyses. (C) 2002 Elsevier Science B.V All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据