What is the fate of runaway positrons in tokamaks?
Massive runaway positrons are generated by runaway electrons in tokamaks. The fate of these positrons encodes valuable information about the runaway dynamics. The phase space dynamics of a runaway position is investigated using a Lagrangian that incorporates the tokamak geometry, loop voltage, radiation and collisional effects. It is found numerically that runaway positrons will drift out of the plasma to annihilate on the first wall, with an in-plasma annihilation possibility less than 0.1%. The dynamics of runaway positrons provides signatures that can be observed as diagnostic tools.
- Department of Modern Physics and Collaborative Innovation Center for Advanced Fusion Energy and Plasma Sciences, University of Science and Technology of China, Hefei, Anhui 230026 (China)
- (United States)
- Princeton Plasma Physics Laboratory, Princeton University, Princeton, New Jersey 08543 (United States)
- School of Physics, Peking University, Beijing 100871 (China)
- Publication Date:
- OSTI Identifier:
- Resource Type:
- Journal Article
- Resource Relation:
- Journal Name: Physics of Plasmas; Journal Volume: 21; Journal Issue: 6; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
- Country of Publication:
- United States
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ANNIHILATION; FIRST WALL; LAGRANGIAN FUNCTION; PHASE SPACE; RUNAWAY ELECTRONS; TOKAMAK DEVICES