Measurement of plasma potential of liquid-He-free superconducting electron cyclotron resonance ion source

Abstract

The plasma potential of liquid-He-free superconducting electron cyclotron resonance ion source was measured as a function of minimum strength of mirror magnetic field (B(min)) and gas pressure with the method based on the retarding electric field. We observed that the plasma potential decreased with increasing B(min) up to 0.5 T and then gradually increased again. The plasma potential increased with increasing gas pressure. When we add the O(2) gas to the Ar plasma (gas mixing method), plasma potential gradually decreased with increasing the O(2) gas pressure.

Effect of source tuning parameters on the plasma potential of heavy ions in the 18 GHz high temperature superconducting electron cyclotron resonance ion source

“…This mass effect, that the plasma potential is lower for the lighter mass ions under same source condition, is clearly seen in have lower plasma potential. 12 It should be noted that in the present measurements, the plasma potential monotonically decreases with increase of charge states of argon in contrast to that obtained by Higashijima et al, 13 where the potential was found to be constant above charge state 5+. A similar variation of the potential was also observed for other ions though it follows the general trend of increase of the plasma potentials for the lower charge states in comparison to higher charge states as observed by others.…”

“…A similar variation of the potential was also observed for other ions though it follows the general trend of increase of the plasma potentials for the lower charge states in comparison to higher charge states as observed by others. 13,14 In the case of Xe, application of a higher dc bias voltage of −500 V reduces the plasma potential further, as shown in Fig. 3.…”

Production of beams from solid materials at Center for Nuclear Study electron cyclotron resonance ion source

“…5 Figure 6 shows the ion beam intensity to coil current of MC1. In this case, the SMR was fixed at one of the three positions of 83.47 mm, 83.95 mm, and 84.45 mm.…”

New superconducting electron cyclotron resonance ion source for RIKEN RI beam factory project

“…Detailed experimental procedure was described in Ref. 8. Figures 1͑a͒ and 1͑b͒ show the plasma potential of Ar plasma and beam intensity of Ar 11+ as a function of B min at the rf powers of 200 and 400 W. The plasma potential gradually decreased with increasing B min up to ϳ0.5 T at both of rf powers.…”