Ion Beam Probe for ST Tokamak.
Abstract
The design, construction and operation of a heavy ion beam probe for measuring plasma density, space potential and current density on the ST Tokamak is described. The beam probe utilizes a 200 keV, 20 Micro amp., T1(+)ion beam and provides three dimensional space resolution of the order of 0.1 cc, time resolution of the order of 0.0001 sec, simultaneous measurements of all three plasma parameters and information that is continuous in both space and time. Preliminary results show good clean signals for all three quantities with signal to noise ratio of the order of 100 to 1. The results establish that there are density fluctuations in the ST plasma that are localized to finite radial positions. The preliminary results also indicate that the space potential goes negative towards the center of the plasma. More work remains in order to obtain quantitative interpretations of the current density signals and to increase the operating range of the beam probe system. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1972
- Accession Number
- AD0737561
Entities
People
- Forrest C. Jobes
- Robert L. Hickok