Modeling of radiative divertor experiments with argon seeding for H-mode plasma in EAST

Abstract

To obtain a quantitative understanding of the recent radiative divertor experiments and to give an instructive prediction for the future relative work performed on EAST, the 2D numerical tool SOLPS has been used to investigate the argon seeded EAST H-mode plasmas. The simulations were mainly based on a typical H-mode discharge with lower single null divertor configuration, in which the partially detached divertor plasma has been achieved due to the argon seeding. First the perpendicular particle and energy transport coefficients for particle density diffusivity D⊥, electron and ion conduction, χ⊥i,e were radially varied to determine the edge transport barrier in H-mode plasma by comparing the simulated upstream profiles of electron temperature (Te) and electron density (ne) with the edge Thomson scattering data. Then the reduction of the particle flux, static pressure, and the peak heat load onto the lower outer divertor target have been reproduced by radiative divertor simulations in agreement with the experimental measurements, which demonstrated that the argon seeding is effective to mitigate the heat load onto the divertor target and achieve partially detached plasma during the H-mode discharge. The simulations also revealed that the strongest radiation occurred near the X-point and in the divertor region for short pulsed argon seeding with a relatively low puffing rate in agreement with bolometer measurements.