Generation and suppression of runaway electrons in EAST lower hybrid current drive experiments

In a lower hybrid current drive experiment on the EAST tokamak in the spring of 2010, the process in which fast electrons transform into runaway electrons was observed, and the way in which lower hybrid waves (LHWs) affect the behavior of runaway electrons was studied. It was found that when the power of LHWs is below a certain threshold, fast electrons excited by LHWs can be accelerated to runaway electrons due to the primary generation mechanism of runaway electrons, but when the power is high enough, fast electrons cannot transform into runaway electrons anymore. No matter how high the power was, the production of runaway electrons due to the secondary generation mechanisms was suppressed.