Bn. Ganguly et A. Garscadden, PHASE-RESOLVED 2-DIMENSIONAL EMISSION PATTERN OF A LOW-FREQUENCY HELIUM DISCHARGE, IEEE transactions on plasma science, 24(1), 1996, pp. 115-116
Time resolved two-dimensional (2-D) plasma-transition emission pattern
s of the 3(3)D to 2(3)P transition in a three-torr low-frequency heliu
m discharge have been measured. The emission patterns are found to be
asymmetric for complementary phases of the current at 30-KHz excitatio
n frequency, however, they are symmetric for 200-KHz excitation freque
ncy, The excitation of the 30-KHz discharge is similar to that of a de
discharge with increasing and decreasing current.