Operating conditions for the generation of stable anode spot plasma in front of a positively biased electrode

Journal Article · Sat Feb 15 04:00:00 EST 2014 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.4857215· OSTI ID:22253185

Park, Yeong-Shin; Lee, Yuna; Dang, Jeong-Jeung ^[1]; Chung, Kyoung-Jae ^[2]; Hwang, Y. S. ^[1]

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1. Department of Nuclear Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of)
2. Center for Advance Research in Fusion Reactor Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of)

Stability of an anode spot plasma, which is an additional high density plasma generated in front of a positively biased electrode immersed in ambient plasma, is a critical issue for its utilization to various types of ion sources. In this study, operating conditions for the generation of stable anode spot plasmas are experimentally investigated. Diagnostics of the bias current flowing into the positively biased electrode and the properties of ambient plasma reveal that unstable nature of the anode spot is deeply associated with the reduction of double layer potential between the anode spot plasma and the ambient plasma. It is found that stability of the anode spot plasma can be improved with increasing the ionization rate in ambient plasma so as to compensate the loss of electrons across the double layer or with enlarging the area of the biased electrode to prevent electron accumulation inside the anode spot. The results obtained from the present study give the guideline for operating conditions of anode spot plasmas as an ion source with high brightness.

• OSTI ID: 22253185
• Journal Information: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 2 Vol. 85; ISSN 0034-6748; ISSN RSINAK
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ANODES
BRIGHTNESS
ELECTRONS
IONIZATION
PLASMA DENSITY
STABILITY