TITLE:
High Density Fluorine Negative-Ion Source Generated by Utilizing Magnetized SF6
AUTHORS:
M. Abid Imtiaz, Tetsu Mieno
KEYWORDS:
Fluorine Negative-Ion; Ion Source; String-Type Plasma; Radial Diffusion; Langmuir Probe; Magnetized Plasma; Sulfur Hexafluoride
JOURNAL NAME:
Journal of Modern Physics,
Vol.5 No.2,
January
22,
2014
ABSTRACT: In a magnetized plasma column generated from an
electronegative gas, negative-ions accumulate around the plasma column via
radial diffusion. In this study, a dc discharge is applied in SF6 gas to produce a plasma column, and the radial density profile of negative-ions is
measured by Langmuir probes using the modified Bohm criterion. The gas pressure
and discharge current dependences of negative-ion density are
also measured. It is found that the negative-ion density of 8.0 ×
1017 m-3 is obtained around the plasma column at r = 1.0
cm when SF6 pressure is 0.13 Pa and discharge current is 0.50
A. The negative-ion density has radial gradient, and the electron density is
much lower in this region.