High-voltage detuning power system of HIRFL-CSRm electron cooler for Dielectronic-Recombination experiments

Abstract

Dielectronic-Recombination (DR) experiments of highly charged ions are performed in the main Cooler Storage Ring (CSRm) at Heavy Ion Research Facility in Lanzhou (HIRFL) accelerator complex. A new detuning power system of the electron cooler is developed to modulate the electron velocity from the cooling velocity and thus control the collision energy in the experiment. In this paper, the design and commissioning of the detuning power system are reported. The detuning power supply adopts the scheme of HVDC (high-voltage DC) and HVA (high-voltage amplifier) connected in series. A FPGA digital controller combined with a high-precision ADC/DAC board is used for multiple-linear voltage settings and feedback. The output maximum DC voltage is −5 kV and the detuning voltage is in the range of 0 to ±1 kV. The main features are the good output voltage stability of 10 ppm and the rapid voltage changing of 10 V/μs. The decoupling and protection of the detuning power supply under the high detuning pulse current are described as well. Finally, a DR spectrum of Ar15+ ions measured with the new detuning power system is presented. The experimental result shows a good resolution, verifying the reliability and feasibility of the design.