Estimation of 2D distributions of electron density and temperature in the JET divertor from tomographic reconstructions of deuterium Balmer line emission
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A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Nuclear Materials and Energy, Volume 25
AbstractEstimates for 2D distributions of electron density, ne, and temperature, Te, have been obtained using reflection-corrected tomographic reconstructions of deuterium Balmer line emission in the JET divertor. The solutions are obtained by a two-dimensional Monte Carlo optimization model, based on intensity ratios of the Balmer Dα, Dγ and Dε emission and the ADAS photon emission coefficients with additional constraints provided by line-integrated spectroscopic measurements of ne and Te. Synthetic benchmarks utilizing EDGE2D-EIRENE simulation outputs yield reproduction of reference ne and Te distributions within 25% with statistical error estimates of 5–15%. Experimental analysis of an L-mode ne ramp shows extension and movement of the outer divertor high-ne region with ne,div up to 1.5 × 1020 m−3 from the outer strike point to above the X-point and decrease of the divertor Te to the range of 0.5–1.0 eV within 25% agreement with the line-integrated measurements. Comparison between the local estimates and their corresponding line integrals suggests underestimation of ne and Te by up to 75% and 50%, respectively, due to the geometric effects of line integration.
| openaire: EC/H2020/633053/EU//EUROfusion
Camera tomography, Detachment, Divertor physics, Divertor spectroscopy, Fusion
Karhunen , J , Lomanowski , B , Solokha , V , Aleiferis , S , Carvalho , P , Groth , M , Kumpulainen , H , Lawson , K D , Meigs , A G , Shaw , A & JET Contributors 2020 , ' Estimation of 2D distributions of electron density and temperature in the JET divertor from tomographic reconstructions of deuterium Balmer line emission ' , Nuclear Materials and Energy , vol. 25 , 100831 . https://doi.org/10.1016/j.nme.2020.100831