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Absorption spectroscopy measurements of argon metastable and resonant atom density in atmospheric pressure Ar-He surface-wave plasmas using a low pressure lamp Diode laser-induced fluorescence measurements of metastable argon ions in a magnetized inductively coupled plasma Phys. Plasmas 13, 052512 (2006); 10.1063/1.2201894Study of the Ar metastable atom population in a hollow cathode discharge by means of a hybrid model and spectrometric measurements

Here we explore the accuracy and applicability of two readily—available, low cost techniques: (a) a branching fraction method and (b) an extended corona method (ECM). A three dimensional Monte Carlo simulation was developed to obtain the electron energy distribution function, a necessary parameter in the extended corona model, and we discuss its dependence on oxygen percentage and discharge pressure. The experiment was conducted with a 13.56 MHz radio-frequency capacitive discharge in Ar and Ar with 10% and 20% O2. Absolute densities of argon resonant 1 s4 and metastable 1 s5 energy levels were calculated at various pressures, powers, and positions inside the resulting plasma using both methods. The ECM was also used for calculation of electron temperature and electron density under the same plasma parameters. Results showed that in pure argon, both methods present a good, inexpensive choice for plasma characterization.

Argon metastable and resonant level densities in Ar and Ar/Cl 2 discharges used for the processing of bulk niobium

A tomographic numerical method based on the two-dimensional Radon formula for a cylindrical cavity has been employed for obtaining spatial distributions of the argon excited levels. The spectroscopy measurements were taken at different positions and directions to observe populations of excited species in the plasmoid region and the corresponding excitation temperatures. Excited argon states are concentrated near the tube walls, thus, confirming the assumption that the post discharge plasma is dominantly sustained by travelling surface wave. An automated optical measurement system has been developed for reconstruction of local plasma parameters of the plasmoid structure formed in an argon supersonic flowing microwave discharge. The system carries out angle and distance measurements using a rotating, flat mirror, as well as two high precision stepper motors operated by a microcontroller-based system and several sensors for precise feedback control. V