| 1. |
- Bilato, R., et al.
(författare)
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Status of the benchmark activity of ICRF full-wave codes within EUROfusion WPCD and beyond
- 2015
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Ingår i: RADIOFREQUENCY POWER IN PLASMAS. - : American Institute of Physics (AIP). - 9780735413368
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Konferensbidrag (refereegranskat)abstract
- As follow-up of the benchmark activity of ICRF full-wave codes within the EUROfusion Code Development for Integrated Modelling project (WPCD), a simple-to-complex approach has been devised for verification of the European ICRF codes, imported in the European-Integrated Modelling infrastructure, which represents a unique environment for input-data sharing and result analysis. This benchmark activity has been recently extended to non-European codes, in particular the ICRF full-wave AORSA code. Here we discussed the results of this benchmark.
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| 2. |
- Hellsten, Torbjörn, et al.
(författare)
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RF Heating for Fusion Product Studies
- 2015
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Ingår i: RADIOFREQUENCY POWER IN PLASMAS. - : American Institute of Physics (AIP). - 9780735413368
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Konferensbidrag (refereegranskat)abstract
- Third harmonic cyclotron heating is an effective tool for accelerating deuterium (D) beams to the MeV energy range, suitable for studying ITER relevant fast particle physics in plasmas without significant tritium content. Such experiments were recently conducted in JET with an ITER like wall in D plasmas with He-3 concentrations up to 30% in order to boost the fusion reactivity by D-He-3 reactions. The harmonic cyclotron heating produces high-energy tails in the MeV range of D ions by on-axis heating and of He-3 ions by tangential off-axis heating. The discharges are characterized by long sawtooth free periods and a rich spectrum of MHD modes excited by the fast D and He-3 ions. The partitions of the power, which depend on the distribution function of D, vary strongly over several slowing down times. Self-consistent modelling of the distribution function with the SELFO-light code are presented and compared with experimental data from fast particle diagnostics.
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| 3. |
- Mantsinen, M. J., et al.
(författare)
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Bulk Ion Heating with ICRF Waves in Tokamaks
- 2015
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Ingår i: RADIOFREQUENCY POWER IN PLASMAS. - : American Institute of Physics (AIP). - 9780735413368
-
Konferensbidrag (refereegranskat)abstract
- Heating with ICRF waves is a well-established method on present-day tokamaks and one of the heating systems foreseen for ITER. However, further work is still needed to test and optimize its performance in fusion devices with metallic high-Z plasma facing components (PFCs) in preparation of ITER and DEMO operation. This is of particular importance for the bulk ion heating capabilities of ICRF waves. Efficient bulk ion heating with the standard ITER ICRF scheme, i.e. the second harmonic heating of tritium with or without He-3 minority, was demonstrated in experiments carried out in deuterium-tritium plasmas on JET and TFTR and is confirmed by ICRF modelling. This paper focuses on recent experiments with He-3 minority heating for bulk ion heating on the ASDEX Upgrade (AUG) tokamak with ITER-relevant all-tungsten PFCs. An increase of 80% in the central ion temperature T-i from 3 to 5.5 keV was achieved when 3 MW of ICRF power tuned to the central He-3 ion cyclotron resonance was added to 4.5 MW of deuterium NBI. The radial gradient of the Ti profile reached locally values up to about 50 keV/m and the normalized logarithmic ion temperature gradients R/L-Ti of about 20, which are unusually large for AUG plasmas. The large changes in the Ti profiles were accompanied by significant changes in measured plasma toroidal rotation, plasma impurity profiles and MHD activity, which indicate concomitant changes in plasma properties with the application of ICRF waves. When the He-3 concentration was increased above the optimum range for bulk ion heating, a weaker peaking of the ion temperature profile was observed, in line with theoretical expectations.
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