Design of Ultra-Fast Charge eXchange Recombination Spectroscopy diagnostic on EAST tokamak

In this article, we present the design of a four-channel Ultra-Fast Charge eXchange Recombination Spectroscopy (UF-CXRS) diagnostic on the EAST tokamak. This diagnostic is based on the active charge exchange to measure ion temperature with a time resolution at the order of 1 μ s and a spatial resolution of 1 cm. The design of the main components is carefully discussed, including the dichroic mirror light path, the fiber, the spectrometer and the customized lens. The theoretical estimation of the emission photon flux has been carried out, proving the feasibility of the whole design.