The ITER-scale negative ion source - SPIDER was officially launched at NBTF facility Padua in June’2018. Recently it achieved another milestone. SPIDER was operated while applying extraction and acceleration voltages, obtaining the first SPIDER hydrogen beam.
ITER-India contributed the Accelerator Grid Power Supply (AGPS) for SPIDER facility. AGPS provides 8MW power at (-) 96kV to the beam source of SPIDER for acceleration of negative ions with specific modulation. PSM based 96kV/75A AGPS has been developed with design redundancy of 15% which allows for tolerating SPS modules failure without leaving the ongoing campaign. The AGPS is designed to turn-off in a time much lower than 100 µs to minimize the energy (20 J) delivered to the arc in case of short circuit or breakdown. AGPS mainly composed of Multi-Secondary Transformers (3nos. 2.8MVA each), Switched Power Supply (SPS) Modules (150nos., 60kW each), FPGA/Real Time based controller and other auxiliaries including passive protection devices. Novel, state of the art technologies for HV insulation such us multiple bushings integrated on large resin insulators and building feedthroughs have been developed. To ensure described functionalities a single AGPS is controlled by 9 powerful synchronous FPGAs managed by real time controller which support high performance requirement of PSM based HVPS like low ripple, high resolution, programmable rise time, fast dynamics, full depth modulation, fast switching off and fast (~few milliseconds) re-application in case of breakdowns.
AGPS was successfully transferred to IO after completing the Site acceptance test in Sept’2018. Subsequently it was integrated with Ion source in Feb’2019 and delivered the first beam on 24th May’2019. Integrated demonstration of indigenously developed AGPS on actual load boosts the confidence for home-grown projects.