Zhang Y P, Liu Yi, Song X Y, Yuan G L, Chen W, Ji X Q, Ding X T, Yang J W, Zhou J, Li X, Yang Q W, Duan X R, Pan C H, Liu Y
Southwestern Institute of Physics, P. O. Box 432, Chengdu 610041, China.
Rev Sci Instrum. 2010 Oct;81(10):103501. doi: 10.1063/1.3488966.
A fast electron bremsstrahlung (FEB) diagnostic technique based on cadmium telluride (CdTe) detector has been developed recently in the HL-2A tokamak for measurements of the temporal evolution of FEB emission in the energy range of 10-200 keV. With a perpendicular viewing into the plasma on the equatorial plane, the hard x-ray spectra with eight different energy channels are measured. The discrimination of the spectra is implemented by an accurate spectrometry. The system also makes use of fast digitization and software signal processing technology. An ambient environment of neutrons, gammas, and magnetic disturbance requires careful shielding. During electron cyclotron resonance heating, the generation of fast electrons and the oscillations of electron fishbone (e-fishbone) have been found. Using the FEB measurement system, it has been experimentally identified that the mode strongly correlates with the electron cyclotron resonance heating produced fast electrons with 30-70 keV.
