Use of fluorescence spectroscopy of hydrogen atoms and BH molecules for measurements of electric fields in a plasma

Abstract

Two laser-aided techniques for electric field (EF) measurements in a plasma have been realized. The first technique is based on the use of Stark splitting of high-lying levels of atomic hydrogen, whereas the second technique is based on the use of Stark mixing of the Λ-doublet energy sublevels of boron monohydride molecules. Both diagnostic techniques have been applied to the measurements of EFs in a hollow cathode discharge. The results of the EF measurements obtained by both techniques are in good agreement. The strength of the EF in a hollow cathode discharge was in the range of 1000–2600 V cm−1 for the dark space region and in the range of 200–300 V cm−1 for the negative glow region.

Electric field distribution in the cathode-fall region of an abnormal glow discharge in hydrogen: experiment and theory

“…In the theoretical part of the CF electric field distribution study, after an analysis of practically all relevant processes, we have arrived at an analytic expression (22) for the distribution of the electric field in the CF region which agrees with the experimental electric field distribution within estimated error bars. We have elaborated that, when used as a model function for data fittings, the derived expression via its best-fit parameters enables measurement of the CF thickness and the mean free path for electrons in the CF region.…”

“…ratio of electron current density at the cathode j e (z g ) and the (overall) discharge current density j 0 r = j e (z g )/j 0 , (22) and the ratio of physical parameters…”

Characterization of hollow cathode fall field strength measured by Doppler-free two-photon optogalvanic spectroscopy via Stark splitting of the 2S level of hydrogen and deuterium

“…Atomic hydrogen isotopes and helium are very good candidates for E-field measurements, because the Stark splitting of all their atomic levels is very well known, and atomic hydrogen also participates in many plasmas of industrial interest. In fact, different techniques for atomic hydrogen and helium have been published most of them included in [1,2] and [3][4][5][6][7][8][9][10] respectively, and the references therein.…”

Electric field strengths in a hollow cathode measured by Doppler-free two-photon optogalvanic spectroscopy via Stark splitting of the 2S level of deuterium

“…Atomic hydrogen is a good choice for E-field measurements, because of the wellknown Stark splitting of all its atomic levels, and also atomic hydrogen participates in many plasmas of industrial interest. In fact, different techniques for atomic hydrogen have been published [2][3][4][5][6][7][8]. For the hydrogen atom, the Stark splitting scales, approximately, with the square of the principal quantum number n [9], i.e.…”