Avalanche Phenomenon of Superthermal Electrons Measured by SDD with New SPHA during ECRH

Two high performance silicon drift detectors (SDD) are installed at the equatorial port with z=0 and z= -16.4cm on HL-2A tokamak, respectively. These SDDs combine with the new and non-conventional software pulse height analyser (SPHA) successfully developed more recently by us to measure the time evolution of soft x-rays spectra, the thermal and superthermal electron temperatures. The high-quality three-dimensional figure of time evolution for soft x-rays energy spectra is easily obtained bycombination of a new SPHA and computer. Therefore, the measurementaccuracies and the time resolutions of thermal and superthermal electron temperatures are also improved. The enhancement phenomenon of superthermal electron during electron cyclotron resonance heating (ECRH) can be explained by the combination of superthermal electron avalanche theory and experimental parameters.