ArticleHuang XL, Zhang YP, Zhu YB, Li X, He L, Li YX, Zhou J, Cheng SK, Yang YM, Bai RH, Zhao X, Tao RY, Chen B, Dai LL, Zeng GQ, Liu Y, Liu MS.
Rev Sci Instrum. 2021 May 01;92(5):053501.
A toroidal soft x-ray array system for spectrum and intensity measurements on the EXL-50 spherical tokamak is described. Silicon drift detectors and digital multichannel analyzers are adopted for all 21 channels of the array, and an average energy resolution of 147 eV at 5.89 keV has been achieved at count rates over 500 kcps. In total, 20 channels of the array are symmetrically observed in both co- and counter-current directions on the EXL-50 mid-plane with a spatial resolution of around 10 cm, and the remaining one serves as a background reference channel. Tungsten emissions from tungsten coating of the limiters on the central post are observed. The influence of hard x rays on measured soft x-ray spectra and system operation is discussed.