Application of RF pumping to plasma purification
Abstract
Methods of preventing contamination of a Tokamak plasma without using a divertor are considered. A strong thermal gradient (eventually obtained by external heating of ions at the center of the plasma) should prevent collisional inward diffusion of impurities in the realistic case where impurities are in the Pfirsch Schluter regime and hydrogen ions are in the banana or plateau regime. Another possibility consists of giving to circulating hydrogen ions an ordered velocity along the flux lines of the order of the diamagnetic velocity. Such a motion could be obtained by a magnetic pumping of small amplitude. Finally we discuss the use of an RF field oscillating at the cyclotron frequency of impurity ions, so that these ions become trapped in ripples of the toroidal field in a region of space where they drift outwards.
- Publication:
-
Plasma Heating in Toroidal Devices
- Pub Date:
- 1974
- Bibcode:
- 1974phtd.symp..166S
- Keywords:
-
- Hydrogen Ions;
- Purification;
- Radio Frequency Heating;
- Tokamak Devices;
- Toroidal Plasmas;
- Cyclotron Frequency;
- Decontamination;
- Ion Cyclotron Radiation;
- Magnetic Pumping;
- Plasma Heating;
- Trapped Particles;
- Plasma Physics