Increase atom/molecular ratio of the hydrogen discharge

6th International Workshop & Summer School on Plasma Physics 2014

Kolodko, D.V.^1 ; Mamedov, N.V.^1 ; Vizgalov, I.V.^1 ; Sinelnikov, D.N.^1 ; Sorokin, I.A.^1

Plasma Physics Department, National Research Nuclear University MEPhI, 31 Kashirskoe shosse, Moscow

115409, Russia^1

关键词: Approximate ratio;    Hydrogen discharge;    Hydrogen molecule;    Hydrogen plasmas;    Influence of water;    Low temperatures;    Plasma temperature;    Wall recombination;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/768/1/012019/pdf
DOI  :  10.1088/1742-6596/768/1/012019

来源: IOP

【 摘 要 】

The high atomic to molecular ion ratio is important for hydrogen ion sources, but in the usual low-temperature hydrogen plasma the molecular ion component is dominating. Proton component can be increased by means of increasing plasma temperature, but in this case energy spectrum will be widened. Single electron collision with a hydrogen molecule may not only lead to the formation of the molecular ion, but also results in the formation of the proton. However, the cross section of the second process is much smaller than of the first (approximate ratio between them being 1:200). Thus, a single electron-molecule collision cannot be an efficient means of proton formation. Atomic hydrogen ions are produced by ionization of neutral hydrogen atoms. As a rule, a lifetime of neutral atoms is too short for ionization. The increase of the hydrogen atom lifetime by reducing the wall recombination coefficient allows us to get more protons. In this work we study the influence of water vapor injection on atom/molecular ratio of hydrogen plasma.