Determining the spectrum of penning electrons by current to a wall probe in nonlocal negative glow plasma

Abstract

It was shown that the spectrum of Penning electrons in a nonlocal equipotential plasma is associated with the second derivative of their current to a wall electrode (sensor). Analytical calculations are confirmed by experimental studies in a negative glow plasma of short DC glow discharge at moderate and high pressures (up to 150 Torr).

Diagnostics of a microhollow cathode discharge at atmospheric pressure

“…However, if the plasma is nonlocal (the energy relaxation length of the electron is equal to or greater than the plasma dimensions) and the electron temperature is low (the self-consistent field of the plasma is low, ∼0), then the fast (highly energetic) part of the EEDF can be measured without distortion. Our group has reported on this problem [29]. In addition, a series of papers has also reported on this problem [15,20,22].…”

“…In addition, a series of papers has also reported on this problem [15,20,22]. According to the literature [29], the plasma generated by the device is non-local and the electron temperature is low. So, it is feasible to diagnose plasma with a wall probe.…”

Development of a Probe System for Measuring the Plasma Parameters and the High-Energy Part of the Electron-Energy Distribution Function

“…In addition, peaks in the regions of 3.1, 4.2, and 6.2 eV are clearly discernible in both cases. They are associated with electrons produced in the reactions of Penning ionization of impurity molecules by metastable helium atoms [13]: (9) He + → +…”

“…It should be noted that the ideas of probe plasma diagnostics, which consist in measuring the highenergy part of the nonlocal distribution function in the plasma region of the negative glow discharge in a buffer noble gas with impurities, have also found application in the development of microplasma analyzers of gas mixtures [11][12][13][14].…”

“…We note that the Impedans and ESPION systems are sensitive to noise while measuring the highenergy part of the electron energy distribution function (EEDF), which requires the manufacture of special filters and amplifiers for comprehensive diagnostics of the gas-discharge plasma [15,19]. In addition, their extremely high cost and large sizes are the main disadvantages of all these systems, which rule out their use as components in microplasma gas analyzers [10][11][12][13][14].…”