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Modeling of the rf discharge initiation in a negative ion source
S Yoshinari1, T Hayami, R Terasaki
1Keio University, 3-14-1 Hiyoshi, Kouhoku-ku, Yokohama 223-8522, Japan.
The Review of Scientific Instruments
|March 3, 2010
Summary
Radio-frequency (RF) negative ion sources are crucial for fusion energy. Numerical modeling reveals that considering wall potential is essential for initiating discharge in these RF ion sources.
Area of Science:
- Plasma Physics
- Fusion Energy Engineering
- Computational Physics
Background:
- Radio-frequency (RF) negative ion sources are promising for fusion reactor plasma heating.
- These sources offer an alternative to traditional arc-discharge sources for H(-) production.
Purpose of the Study:
- To clarify discharge initiation conditions in RF negative ion sources.
- To develop a numerical model for analyzing electron behavior in RF fields.
Main Methods:
- Utilized the finite difference time domain Monte Carlo method for numerical modeling.
- Analyzed the electron energy distribution function within an RF field.
Main Results:
- Numerical simulations indicated that discharge initiation fails without accounting for wall potential.
- Wall loss significantly impacts the discharge initiation process.
Conclusions:
- Accurate modeling of RF negative ion sources requires consideration of wall potential.
- Future models should incorporate ion dynamics to evaluate wall potential and electron loss.
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