Abstract

The X-ray energy spectra were measured during electron cyclotron current drive (ECCD) and fast wave current drive (FWCD) experiments in the DIII-D tokamak. High energy electrons, over 100 keV, were observed during ECCD near the plasma center and enhanced radially by the effect of downshifted frequency. Tail formation with the maximum energy of 50 keV was observed clearly during 2 T, 0.8 MA FWCD experiments. For combined FWCD and ECCD, the bulk heating efficiency was increased over the case with FW only, with ηe∼2.3×1019 m-3 keV/MW, and it was stronger for the counter (CTR) case than the co (Co) case. (Here Co corresponds to the direction of launched wave which will enhance the plasma current. CTR refers to the opposite direction.) However, the coupling of FWs to high energy electrons produced by ECH was stronger for the Co case.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.