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The High Intensity heavy ion Accelerator Facility (HIAF) and Low Energy heavy ion Accelerator Facility (LEAF) of IMP are under construction. They will comprise many superconducting devices and components, such as magnets and current leads, with the superconducting materials covering NbTi, Nb3Sn and HTS. On the other hand, most of the superconducting devices have a high energy density and complex structure, requiring a targeted and active protection. In previous quench protection systems implemented at IMP, the quench detection was implemented in software or as microcontroller-based equipment, where power supplies in superconducting circuit provided quench detection functionality as well. These systems have some disadvantages, such as limited functionalities, poor reliability and high susceptibility to interference. Therefore, a new type of quench detection system (QDS) based on programmable FPGA and Isolated analogue input front-ends was developed to overcome these challenges. It is important to note that in the test facilities, there is no ionizing radiation, the QDS does not require radiation tolerance, thus a commercial programmable FPGA product was chosen as the development platform. The QDS is currently being put into operation, and some good results have been obtained in the cold tests of MCBRDP2 (belongs to HL-LHC, NbTi magnet) and FECR (belongs to LEAF, Nb3Sn magnet). Based on these successful applications, the new QDS has proven its functionality. The recorded data and practical experience also provided relevant information for the detection algorithms and functional upgrades. [ABSTRACT FROM AUTHOR]

High-temperature superconductors (HTS) are materials that hold great promise for future particle-accelerator plants. YBa2Cu3O7-x-based (YBCO) second-generation coated conductor coils can produce the intense field needed for ion confinement. Such coils can act as a radiation resistance magnet when exposed to radiation, and therefore, it is essential to better understand irradiation responses and defect creation in YBCO superconductors. The influence of laser or ion irradiation on the electrical characteristics of HTS has been studied previously; however, most results remain ambiguous and inconsistent. Degradation of or incremental changes in the critical current of the HTS tap are currently only observed and explained via irradiation dose. The relation between irradiation defects and macro-multi-field responses has yet to be established for YBCO tapes, for magnet design and operation. In this study, YBCO (2 G HTS) taps with Ag, Cu–Ag, and Cu protective cap layers were selected as targets of Nd-laser irradiation, at varying power. Irradiation defects were formed in YBCO taps, and irradiation dose was monitored as a function of superconducting properties and mechanical behaviors. The critical current and its N-values eventually degrade under intense Nd-laser irradiation, and the mechanical behavior of YBCO tapes shows nonlinear features after irradiation. Scanning electron microscopy and x-ray energy-dispersive spectrometry were applied to investigate the micro-defect changes that occurred in the taps after each Nd-laser irradiation dose. Micro-structural observations showed that the protective layers were critical for radiation resistance in YBCO taps. Furthermore, the macro-stress dependence of the critical current field was measured before and after Nd-laser irradiation to establish the relationship with micro-defect morphology by Nd-laser irradiation. [ABSTRACT FROM AUTHOR]