Modelling interaction of Runaway electrons with Whistler waves using KORC-AORSA model

Resonant interactions between high energy runaway electrons (REs) and whistler waves may scatter the REs to higher pitch angles leading to increased RE energy dissipation via synchrotron radiation. DIII-D observations of RE-driven whistler waves [1] suggest launching whistler waves to mitigate the deleterious effects of REs on the plasma facing components via resonant interactions with whistlers. We have numerically studied the interactions of REs with whistler waves in DIII-D and analyzed the change in the energy and pitch angle of the REs due to whistlers using the coupled KORC-AORSA model. In this framework, we follow full orbit RE trajectories using the KORC code in the presence of whistler wave fields from the AORSA code with the DIII-D whistler wave experimental data. The simulation results indicate a dependence of gain in RE energy on the instantaneous energy, pitch angle, whistler field amplitude and the radial location of the REs. Our simulation model can be used to get physical insights into future experiments on whistler waves and REs interactions.



[1] D. A. Spong et al., Phys. Rev. Lett., 120, 155002 (2018).



*Work supported by US DOE under DE-FC02-04ER54698, DE-AC05-00OR22725 and DE-FC02-04ER54698.