Optimizing the electrode configuration of a cylindrical discharge-type fusion device by computational and experimental analysis

A new design of a cylindrical discharge-type fusion device is proposed to achieve the precise alignment of components and prevent abnormal discharges. Cylindrical insulators that act as parts of the vacuum boundary and fix the relative position between cathode and anodes were used. The configuration of the electrodes was optimized to maintain stable discharge at low pressures and high discharge voltages, which enhances the neutron yield. The optimization was performed via analysis of the electric field and ion movements by developing a 2D code, and the results were experimentally verified. The results show that grounding the anodes is better for stable discharge at lower pressures. The optimized combination of the anode height and cathode overhang is 3 cm and 1 cm, or 2 cm, respectively. The discharge characteristics and neutron production rate were then experimentally measured for the optimized configuration. The attained highest discharge voltage (instantaneous) was ∼50 kV and the neutron production rate of 3 × 10⁴ n/s was obtained by continuous discharge with an applied voltage of 30 kV and discharge current of 30 mA. (author)