Optical and Langmuir Probe Diagnostics in a Magnetized Hollow Cathode Arc

Abstract

The paper presents measurements of the plasma parameters of a hollow cathode arc (HCA) using Langmuir probes (LPs) as well as optical emission spectroscopy (OES). The plasma of a HCA is characterized by a high energy beam‐like component of electrons which causes a relatively high ionization degree. Data of LP measurements were evaluated to obtain the electron energy distribution function (EEDF), which could be approximated by the generalized Druyvesteyn distribution. The spectroscopic method used is based on the analysis of the molecular spectra of nitrogen and the atomic spectra of He and Ar. By considering several lines with different excitation thresholds the EEDF could be obtained in a trial and error procedure using a regularization routine. Because of the high electron density in HCA, stepwise processes initiated by metastable states of Ar and He atoms and N2 molecules are taken into account also. The data evaluated from spectroscopic measurements are compared with those from LP measurements. The EEDF measured by OES could be approximated by a Maxwellian distribution function.

A compact new incoherent Thomson scattering diagnostic for low-temperature plasma studies

“…On the other hand, the bottom panel view, while appearing to reveal a Maxwellian distribution, can show only truly marked deviations from Maxwellian behavior (due to the logarithmic vertical scale). Some apparent deviation from Maxwellian behavior has been observed for a magnetized version of the hollow cathode plasma source studied with Langmuir probes [57].…”

Nitrogen Radical and Plasma Diagnostics in Dual Frequency Hybrid Plasmas to Investigate N2/SiH4 PECVD Process

“…Among the various techniques, the emission spectroscopy methods like OES [11,12,[26][27][28][29][30][31] and VUVES [12] have been used to determine the rotational temperature T rot of molecules. This estimation technique is used by fitting the experimental molecular bands of N 2 .…”

Measurement of Some Argon Plasma Parameters Glow Discharge Under Axial Magnetic Field

“…The ion beam current in an end Hall-type ion source with a magnetic mirror field are investigated * Corresponding author This is an open access under a CC BY-NC-SA 4.0 license (https://creativecommons.org/licenses/by-nc-sa/4.0/) regarding magnetic gradient (Tang, 2007). The plasma parameters of a hollow cathode arc discharge (HCAD ), have been calculated by employing optical emission spectroscopy under magnetic field (Avaria, 2009). This is for nitrogen gas and used (200-1100) nm (Kolpaková, 2011).…”