Engineering Improvements and Physics Studies of the Accelerated Compact Toroid in the CTIX Injector

Abstract

The main goals of the experimental studies on the CTIX compact toroid accelerator are to improve CT parameters through engineering modification, and to quantify CT dynamics by the comparison of experimental measurements to MHD theories. Over this research period, the final CT kinetic energy has been increased by about 30%, with increased efficiency of first-cycle capacitor energy utilization. The efficiency increase is obtained through a combination of engineering modification to passive magnetic switching (saturable Metglas cores), and a fast gas system in the acceleration section of CTIX. Using the new switching system and gas puffing, the final CT density has been increased up to a factor of 5, compared to operation without puffing. The second task of the CTIX project is to compare the experimental data with the existing theoretical models. The most relevant models are that of force-free equilibrium, and a Hall-MHD model. From analysis of magnetic field data, it is determined that the Hall-MHD model gives better agreement, if effects of fluid vorticity are also included. This analysis has been reported in a recent paper (S. J. Howard et al., Submitted). Finally, a new plasma density measurement technique, deflectometry, has been compared with conventional interferometry method. A significant data base has been produced to show that the deflection measurements correlate well with the HeNe laser interferometry.