Abstract
The ion energy distribution in a medium-vacuum nitrogen arc plasma with a titanium cathode was measured using a Gridded Energy Analyzer. The parameters were pressure (0.1 to 2Pa) and distance from cathode, L, (155 to 380mm). The diameter and the length of the vacuum vessel were 400 and 600mm, respectively. The arc current was 50 A DC. The experimental results show that; the ion density decreases as the L increase, the maximum ion energy is about 60eV, the maximum probability energy of ions is 30eV for 0.1Pa whereas 0eV for 2Pa, and between these pressures it decreases with increasing L.
The existence of beam component of the ions is discussed. As a result, it is found that ion movement turns from beam-like to random as the pressure and the L increase.
