Effect of EC waves on relativistic-electron-driven whistler waves

2024 Research Campaign, Frontier Science

Purpose of Experiment

Startup Runaway Electrons (REs) can present an operational risk to tokamak operation. It has been observed in recent experiments on DIII-D and TCV that application of Electron-Cyclotron Heating (ECH) to the plasma can result in an expulsion and decline of the RE population. Higher ECH powers have been observed to result in faster RE expulsion, and off-axis ECH to result in slower expulsion. The exact mechanism for this increase in radial transport of the REs when ECH is applied is not known and has not been identified. This Frontier Science experiment aims at identifying such a mechanism and further understanding the physics of ECH-induced RE expulsion.

Experimental Approach

Specifically, this experiment will explore the role of ECH vs EC-caused current drive on RE expulsion, the effects of keeping the loop voltage constant, and the dependence on density of the RE loss rate.