Two invited talks on impurity transport and detached divertor physics topics in 3D boundaries presented at APS-DPP meeting 2019.

Two invited talks were delivered at the 2019 venue of the APS-DPP divisional conference in Fort Lauderdale. Edward Hinson reported on first time results on helium decontamination of future burning fusion plasmas by application of resonant magnetic perturbation fields. This method is chosen as a way to stabilize harmful plasma edge instabilities. Edward Hinson has found through experiments at the DIII-D National Fusion Facility that a beneficial add-on effect of such small amplitude perturbation fields is that helium gets exhausted from the system about twice as fast as without the fields applied. This is very promising for burins plasmas in which helium is produced as fusion product, i.e. the ash of the fusion process, and needs to be exhausted from the fusion plasma medium effectively.

Heinke Frerichs reported from a recent enhancement to the state of the art 3D plasma edge transport and kinetic neutral code EMC3-EIRENE. The code was stabilized for low temperature plasma conditions that occur in regimes of reduced heat and particle fluxes to plasma facing components. This detached plasma regime is a key baseline operational scenario in ITER and beyond. Dr. Frerichs has modeled for the first time with the enhanced code version how the small scale magnetic perturbation fields used for plasma edge stability control will facet this detached plasma regime at ITER. His studies presented in this invited talk showed that a 3D plasma boundary evolves with so far unconsidered heat fluxes to vulnerable areas of the ITER divertor. Dr. Frerichs work will help to optimize the use of the stabilizing magnetic fields to avoid exposure of these divertor areas and enable stable operation of the divertor plasma at ITER within the presently defined baseline.

Students in the 3DP PSI group also presented posters on particle exhaust with 3D fields (K. Flesch) as well as the status of the development of a thermal helium beam diagnostic for the W7-X stellarator (E. Flom). Scoping studies to establish a helicon plasma in a magnetic field mirror setup were presented by M. Granetzny.

— News: 10-20-2019