The Pre-research of a Long-distance Target Imaging and Temperature Measurement System

The China initiative Accelerator Driven System (CiADS) is a large accelerator facility aiming for the nuclear fuel transmutation, which needs a critical target profile and temperature monitor, claimed as a long-distance Target Imaging System (TIS), to ensure the safety of 2.5\ \rm MW proton bombarding the target at its first stage. This paper presents the preliminary researches of system details, including the design of a 41.5\ \rm m long-distance optics route, and tests and experiments on the fluorescent material Al₂O₃:Cr³⁺, and the dual-wavelength comparison for precise temperature measurements as well. These experiments include X-Ray Diffraction (XRD) for the material lattice, Photo-Luminescence (PL) tests for the light emission efficiency and lifetime, and Scanning Electron Microscope (SEM) tests for the surface roughness and elemental composition. According to ZEMAX simulations, the spatial resolution are better than 1.5\ \rm mm and 12\ \rm mm requirements in the visible and infrared wavelength, respectively. The fluorescent properties like different \rm Cr^3+ doping ratios or coating techniques have also been determined after tests. In addition, this paper also conducts some experiments on dual-infrared temperature measurement.