Optimal Design of a Grid-Cathode Structure in a Spherically Convergent Beam Fusion Device by Response-Surface Methodology Combined With Experimental Design

To apply fusion energy through a spherically convergent beam fusion (SCBF) device as a portable neutron source, neutron production is very important. The rate of production is greatly dependent upon the ion current, which is closely related to the potential-well structure within a grid cathode. In this paper, we propose a design method by varying the cathode-ring sizes to produce an optimal grid-cathode structure in an SCBF device. The optimization is based on response-surface methodology (RSM); however, full factorial design is also applied to increase the precision of optimization and reduce experiment iteration in the application of RSM. The finite-element method, combined with the flux-corrected transport algorithm, is employed to calculate the ion current. From the optimized model, a higher ion current is calculated, resulting in a deeper potential well.