Title:   Plasma response scenarios for ELM suppression and their link to the divertor heat and particle flux in DIII-D 

Speaker:  Dr. Dmitri Orlov

Place:    玉泉校区教11-413

Date and time: 6月17日14:00--14:40

Abstract：

Experiments in DIII-D have been performed to modify the divertor heat and particle flux pattern during suppression of ELMs with resonant magnetic perturbation (RMP) fields. In this work, we assessed the impact of small current modulations in a subset of DIII-D I-coils on pedestal profiles, transport and stability as well as divertor conditions. Different I-coil subset ramps were performed allowing for a slow transition of the divertor footprints from n=3 to n=2 and n=1 distributions. We obtained long periods of RMP ELM suppression with slow I-coil quartet ramps. Strong divertor particle flux splitting was observed in these discharges as well as modulation of the divertor heat flux due to changes in toroidal spectrum of applied perturbation. Experimental results are compared to vacuum, linear and nonlinear ideal and resistive plasma response models to understand the role of the plasma response on quantitative predictions of the divertor flux splitting. Work supported by US DOE under DE-FC02-04ER54698 and DE-FG02-05ER54809.

Bio:
Dr. Dmitri Orlov is an Associate Project Scientist with the Center for Energy Research at UC San Diego. He is presently performing computational and experimental research at the DIII-D National Fusion Facility. His research focuses on controlling the edge instabilities in high-confinement regimes in present-day tokamaks and future plasma burning devices, including ITER, transport in the core and edge of the tokamaks with 3D perturbation fields, heat and particle transport to the divertor surfaces, and thermal protection systems materials. He leads two multi-institutional collaborations on the Theory and Frontier Plasma Science. He is also involved in research collaborations at KSTAR, EAST, AUG, NSTX, and ITER. Dr. Orlov holds a PhD from the University of Notre Dame (‘06) and an MS with Honors from the Moscow Institute of Physics and Technology (‘00). He worked at the US Air Force Academy before joining UC San Diego. He is a member-at-large of the APS DPP Executive committee and a member of the US TTF Executive Committee leading the Transport in 3D Fields working group. He is chair of the UCSD CER Diversity and Outreach committees. He has authored and co-authored more than 50 refereed journal papers and presented multiple invited talks at domestic and international conferences.