Operation of the DNB on Alcator C-Mod
Abstract
A diagnostic neutral beam (DNB) has been installed on Alcator C-Mod to allow the use of CXRS, BES, MSE, and other beam diagnostics in experiments on turbulence and transport. The beam can be operated at up to 50 kV, 6 A extracted current for 100 ms pulses. It can be modulated at up to 1 kHz and can generate H, D, and He beams. Integration of the beam into C-Mod operations required that a number of issues be addressed: interaction of C-Mod power supplies with DNB supplies which caused the beam to operate at currents below perveance, the flow of neutral gas from the beam into C-Mod which affects both breakdown and current rise, and the impact of the beam on the plasma H/D ratio which affects RF heating efficiency. A model for the beam operation is being developed to assist in optimization of beam performance. Modeling of the beam penetration is being benchmarked against observations of the beam emission. The injection of the beam into neutral gas to determine the size of the beam will be discussed. Use of the beam for CXRS will also be discussed.
- Publication:
-
APS Division of Plasma Physics Meeting Abstracts
- Pub Date:
- October 2000
- Bibcode:
- 2000APS..DPPUP1107E