Development of pulse power supply system based on Marx generator for the arc ion source of the VEST NBI

•A high-power and short-pulse power supply system is developed to operate the pulse arc ion source of NBI system of VEST with total ion beam power of 0.8MW.•Ability of output voltage modulation to change the incident ion beam energy in the short pulse operation is confirmed by using high power pulse generator system based on Marx modulator.•Compact and cost-effective power supply system utilizing commercial batteries and ultra-capacitors for the pulse arc-discharge plasma source of the VEST NBI system is designed and constructed.