Parametric study of radiofrequency helium discharge under atmospheric pressure.

HUSSAIN, SAFDAR; AHMAD QAZI, HAFIZ; NIAZ, SHANAWER; BADAR, MANZOOR

The parameters of radiofrequency helium discharge under atmospheric pressure were studied by electrical and optical measurements using high voltage probe, current probe and optical emission spectroscopy. Two discharge modes α and γ were observed within certain limits. During α to γ mode transition, a decrease in voltage (280-168 V), current (2.05-1.61 A) and phase angle (76-56) occurred. The discharge parameters such as resistance, reactance, sheath thickness, electron density, excitation temperature and gas temperature were assessed by electrical measurements using equivalent circuit model and optical emission spectroscopy. In α mode, the discharge current increased from 1.17 to 2.05 A, electron density increased from 0.19 × 10 to 0.47 × 10 cm while sheath thickness decreased from 0.40 to 0.25 mm. The excitation temperatures in the α and γ modes were 3266 and 4500 K respectively, evaluated by Boltzmann's plot method. The estimated gas temperature increased from 335 K in the α mode to 485 K in the γ mode, suggesting that the radiofrequency atmospheric pressure helium discharge can be used for surface treatment applications.

RADIO frequency; ATMOSPHERIC pressure; OPTICAL measurements; NUCLEAR excitation; EMISSION spectroscopy

Pramana: Journal of Physics, 2016, Vol 87, Issue 6, p1

0304-4289

Academic Journal

10.1007/s12043-016-1296-5