Fueling efficiency of pellet injection on DIII-D
- Oak Ridge National Lab., TN (United States)
- Lawrence Livermore National Lab., CA (United States)
- General Atomics, San Diego, CA (United States)
Pellet injection has been used on the DIII-D tokamak to study density limits and particle transport in H-mode and inner wall limited L-mode plasmas. These experiments have provided a variety of conditions in which to examine the fueling efficiency of pellets injected into DIII-D plasmas. The fueling efficiency defined as the total increase in number of plasma electrons divided by the number of pellet fuel atoms, is determined by measurements of density profiles before and just after pellet injection. The authors have found that there is a decrease in the pellet fueling efficiency with increased neutral beam injection power. The pellet penetration depth also decreases with increased neutral beam injection power so that, in general, fueling efficiency increases with penetration depth. The fueling efficiency is generally 25% lower in ELMing H-mode discharges than in L-mode due to an expulsion of particles with a pellet triggered ELM. A comparison with fueling efficiency data from other tokamaks shows similar behavior.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); General Atomics, San Diego, CA (United States)
- Sponsoring Organization:
- USDOE Office of Energy Research, Washington, DC (United States)
- DOE Contract Number:
- AC03-89ER51114; W-7405-ENG-48; AC05-96OR22464
- OSTI ID:
- 672064
- Report Number(s):
- ORNL/CP-98390; CONF-980560-; ON: DE98005671; BR: AT5010200; TRN: 99:000804
- Resource Relation:
- Conference: 13. international conference on plasma surface interactions, San Diego, CA (United States), 18-22 May 1998; Other Information: PBD: May 1998
- Country of Publication:
- United States
- Language:
- English
Similar Records
Investigation of physical processes limiting plasma density in high confinement mode discharges on DIII-D
Improved core fueling with high field side pellet injection in the DIII-D tokamak