Effect of heating scheme on SOL width in DIII-D and EAST

Effect of heating scheme on SOL width in DIII-D and EAST

Blog Article

Joint DIII-D/EAST experiments in the radio-frequency (RF) heated H-mode scheme with comparison to that of neutral beam (NB) heated H-mode scheme were carried out on DIII-D and EAST under similar conditions to Tatami Cushion examine the effect of heating scheme on scrape-off layer (SOL) width in H-mode plasmas for application to ITER.A dimensionally similar plasma equilibrium was used to match the EAST shape parameters.The divertor heat flux and SOL widths were measured with infra-red camera in DIII-D, while with divertor Langmuir probe array in EAST.

It has been demonstrated on both DIII-D and EAST that RF-heated plasma has a broader SOL than NB-heated plasma when the edge electrons are effectively heated in low plasma current and low density regime with low edge collisionality.Detailed edge and pedestal profile analysis on DIII-D suggests that the low edge collisionality and ion orbit loss effect may account for the observed broadening.The joint Water Flow Sensor experiment in DIII-D has also demonstrated the strong inverse dependence of SOL width on the plasma current in electron cyclotron heated (ECH) H-mode plasmas.

Keywords: SOL width, Radio-frequency heating, Neutral beam heating, Low collisionality.