Loading...
Please wait, while we are loading the content...
Similar Documents
Plasma heating and generation of energetic ions with novel three-ion ICRF scenarios on Alcator C-Mod and JET tokamak facilities
| Content Provider | Semantic Scholar |
|---|---|
| Author | Kazakov, Yevgen O. |
| Copyright Year | 2016 |
| Abstract | This talk will report the first experimental results of novel three-ion ICRF scenarios (two or more majority ion species and one minority) for plasma heating and generating energetic ions in fusion facilities [1]. The key feature of these scenarios is strong absorption of RF power possible at lower concentrations of minority ions than in two-ion plasmas. Effective plasma heating by injecting a small amount of 3He ions into H-D plasma mixtures with nH/ne ∼ 70% has been successfully demonstrated in Alcator C-Mod and JET tokamaks. In C-Mod, efficient plasma heating was observed for 3He concentrations from 0.4-2%. During the discharges, a strong increase in Alfvén eigenmode activity was found to coincide with the addition of 3He to the H-D plasmas [2]. Even lower 3He concentrations (∼ 0.2%) were utilized in recent JET experiments. The potential of the D-(3He)-H scenario for plasma heating and generating MeV-range ions in JET plasmas was confirmed by a set of independent measurements, including stabilization of sawteeth, characteristic γ-ray emission, fast-ion loss detector. Furthermore, toroidal Alfvén eigenmodes with a range of toroidal mode numbers n were detected, which is another indication for the presence of significant population of high-energy 3He ions in a plasma. The discussed mechanism of resonant wave-particle interaction opens up various unexplored opportunities for ICRF system, including new scenarios for plasma heating. Three-ion ICRF scenarios are also relevant for the experimental programme of ITER. The possibility of using intrinsic 9Be impurities as the minority (instead of 3He) was suggested for heating bulk ions in D-T plasmas of JET and ITER [3], as well as heating trace amounts of 3He and 4He ions in H majority plasmas of ITER. The latest results and simulation comparisons will be presented. [1] Y. Kazakov et al., Nucl. Fusion 55, 032001 (2015) [2] J. Wright et al. and Y. Lin et al., this conference [3] Y. Kazakov et al., Phys. Plasmas 22, 082511 (2015) |
| File Format | PDF HTM / HTML |
| Volume Number | 2016 |
| Alternate Webpage(s) | http://absimage.aps.org/image/DPP16/MWS_DPP16-2016-001808.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
