Sub-divertor fuel isotopic content detection limit for JET and its impact on ICRF core heating and DTE2 operationsupa/sup

0538970 - ÚFP 2021 RIV AT eng J - Journal Article
Klepper, C.C. - Pégourié, B. - Vartanian, S. - Goniche, M. - Delabie, E. - Van Eester, D. - Lerche, E. - Sips, G. - Borodkina, Irina - Douai, D. - Jepu, I. - Kruezi, U. - Matthews, G. F. - Widdowson, A.
Sub-divertor fuel isotopic content detection limit for JET and its impact on ICRF core heating and DTE2 operationsupa/sup.
Nuclear Fusion. Roč. 60, č. 1 (2020), č. článku 016021. ISSN 0029-5515. E-ISSN 1741-4326
EU Projects: European Commission(XE) 633053 - EUROfusion
Institutional support: RVO:61389021
Keywords : Fusion fuel isotopic content * iter * jet dte2 * JET ITER-like wall * Magnetic fusion energy * Residual gas analysis
OECD category: Fluids and plasma physics (including surface physics)
Impact factor: 3.179, year: 2020
Method of publishing: Limited access
https://iopscience.iop.org/article/10.1088/1741-4326/ab4c5a

The ability to detect and control fuel isotopic content down to a 1% concentration level is greatly important for the upcoming JET DTE2 campaign, as well as its associated TT and DD phases. A reduction of H minority concentration even from 2% down to 1% is shown here to have significant impact on the effectiveness of ion cyclotron range of frequencies core heating, while the ability to maintain T or D concentration at or below 1% is critical to limiting fusion neutron generation in the DD and TT phases, correspondingly. The sub-divertor measurement of (global) isotopic concentration, based on Penning-activated optical spectroscopy, can deliver minimally this 1% detection for DTE2 as long as light collection from the Penning emission can be optimized and gradual window transmission deterioration can be minimized. This is simulated with a statistical analysis developed to understand the uncertainty sources in the JET DTE1 data, as well as to guide the optimization of an upgraded, fuel-isotopic content (and helium-ash concentration) gas analysis system for the JET divertor in preparation for DTE2. While this random error can be reduced to allow measurement substantially below 1% concentration, analysis also shows a systematic error of up to 1% understood to be due to plasma–surface interactions in the Penning excitation, suggesting that 1% may still be the low-end limit for the sub-divertor measurement, unless a Penning-source conditioning approach is also developed.
Permanent Link: http://hdl.handle.net/11104/0316702