Develpoment of a one-meter plasma source for heavy ion beam chargeneutralization
Highly ionized plasmas are being employed as a medium for charge neutralizing heavy ion beams in order to focus to a small spot size. Calculations suggest that plasma at a density of 1-100 times the ion beam density and at a length {approx} 0.1-1 m would be suitable for achieving a high level of charge neutralization. A radio frequency (RF) source was constructed at the Princeton Plasma Physics Laboratory (PPPL) in support of the joint Neutralized Transport Experiment (NTX) at the Lawrence Berkeley National Laboratory (LBNL) to study ion beam neutralization. Pulsing the source enabled operation at pressures {approx} 10{sup -6} Torr with plasma densities of 10{sup 11} cm{sup -3}. Near 100% ionization was achieved. The plasma was 10 cm in length, but future experiments require a source 1 m long. The RF source does not easily scale to the length. Consequently, large-volume plasma sources based upon ferroelectric ceramics are being considered. These sources have the advantage of being able to increase the length of the plasma and operate at low neutral pressures. The source will utilize the ferroelectric ceramic BaTiO{sub 3} to form metal plasma. A 1 m long section of the drift tube inner surface of NTX will be covered with ceramic. A high voltage ({approx} 1-5 kV) is applied between the drift tube and the front surface of the ceramic by placing a wire grid on the front surface. Plasma densities of 10{sup 12} cm{sup -3} and neutral pressures {approx} 10{sup -6} Torr are expected. A test stand to produce 20 cm long plasma is being constructed and will be tested before a 1 m long source is developed.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE Director. Office of Science. Office of Fusion EnergySciences, Princeton Plasma Physics Laboratory
- DOE Contract Number:
- DE-AC02-05CH11231
- OSTI ID:
- 859926
- Report Number(s):
- LBNL-56913; HIFAN 1386; R&D Project: Z41003; BnR: AT5015031; TRN: US200523%%121
- Resource Relation:
- Conference: 15th International Symposium on Heavy IonInertial Fusion, Princeton, NJ, 06/7-11/2004
- Country of Publication:
- United States
- Language:
- English
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