Enhancement in ion beam current with layered-glows in a constricted dc plasma ion source

Journal Article · Mon Feb 15 04:00:00 EST 2010 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.3271252· OSTI ID:22053879

Park, Yeong-Shin; Hwang, Y S ^[1]

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1. Department of Nuclear Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of)

High current mode has been discovered and investigated in a constricted dc plasma ion source. As discharge currents exceed a certain threshold, voltage to sustain the constricted dc plasma suddenly falls down to almost half of the value. In this sense, constricted dc plasmas can be sustained at much higher current than in conventional mode operation at a fixed discharge voltage. Phenomenally, several discrete layered-glows are created between an anode glow and a cathode glow. The layers are thin and divided by dark spaces where charged particles can be accelerated. In this high current mode, ion beam current density is about 100 times higher than in conventional mode at the same voltage. It is noteworthy that lower gas pressure is desirable to sustain the layered-glow mode, which is also profitable for ion source in terms of differential pumping. Ion current density exceeds 300 mA/cm{sup 2} at low discharge power of 175 W where ion density of plasma ball is estimated to be over 3.7x10{sup 12} cm{sup -3}.

• OSTI ID: 22053879
• Journal Information: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 2 Vol. 81; ISSN 0034-6748; ISSN RSINAK
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ANODES
BEAM CURRENTS
CATHODES
CURRENT DENSITY
ELECTRIC POTENTIAL
GLOW DISCHARGES
ION BEAMS
ION DENSITY
ION SOURCES
LAYERS
PLASMA
PLASMA DENSITY