The development of radio frequency ion source for NPA calibration system

A high-frequency ion source for Neutral Particle Analyzer (NPA) calibration system was developed in this work. The performance parameters were experimentally measured to obtain the relationship between the beam current and the high-frequency oscillator plate voltage, and the extraction voltage, and the discharge pressure. The results show that the ion current of 66 μA can be extracted when the working gas is hydrogen, the plate pressure is 580 V, the extraction voltage is 1600 V, the focusing voltage is 1550 V and the pressure is 9.5 × 10^-4 Pa. Under the condition of 41 μA, the stability is better than 2.6 % within 4 hours. The main factors affecting the stability of the beam are the fluctuation of the working gas pressure in the discharge tube and the plasma temperature. It's found that the performance of this high-frequency ion source fulfill the designed requirements for the calibration of the NPA system on the HL-2 A/M. (authors)