Energy spectra of Penning electrons in non-local plasma at middle and high pressures

18th International Summer School on Vacuum, Electron and Ion Technologies

Stefanova, M.^1 ; Pramatarov, P.^1 ; Kudryavtsev, A.^2 ; Peyeva, R.^1

Acad. G. Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tsarigradsko Chaussee, 1784 Sofia, Bulgaria^1

St. Petersburg State University, 7-9 Universitetskaya Nab., 199034 St.-Petersburg, Russia^2

关键词: Characteristic energy;    Collisional energies;    Discharge volume;    Energy spectra;    Fast electrons;    High pressure;    Microdischarges;    Penning ionization;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/514/1/012052/pdf
DOI  :  10.1088/1742-6596/514/1/012052

来源: IOP

【 摘 要 】

A recently-developed collisional electron spectroscopy (CES) method enabled us to measure the energy spectra of groups of fast non-local electrons in a collisional mode at high pressures, where no collisional energy relaxation of electrons in the different groups takes place in the volume, and the different groups of electrons behave independently of each other. We recorded the energy spectra of groups of fast electrons created via Penning ionization of Ar and N2impurities by metastable He atoms at He pressures of 30 and 200 Torr. The experiments were conducted in the non-local negative glow plasma of a short dc microdischarge. The Penning electrons' energy spectra were recorded by means of an additional electrode-a sensor located at the boundary of the discharge volume, in contrast with the classical Langmuir probe. The spectra are characterized by the appearance of maxima at characteristic energies corresponding to the energy of the electrons released via Penning reactions. Using the Penning electrons' energy spectra, one can detect and identify the presence of different atomic and molecular admixtures in He at high pressures.