Scaling properties of runaway electrons in HL-1M tokamak

A simple one-dimensional numerical model including generation, acceleration and loss effects for runaway electrons are used to deduce the runaway energy epsilon(r). The simulation results are presented in a form of a scaling law of epsilon(r) on plasma parameters. The scaling of epsilon(r) and therefore the runaway confinement time tau(r) and runaway electron diffusivity D-r have been studied in HL-1M tokamak, by measuring the hard-X ray spectra under different experimental conditions. A tentative explanation for the scaling of obtained data based on the effects from magnetic turbulence is presented.