The Study of TVS Trigger Geometry and Triggered Vacuum Conditions
  This presentation focuses on the optimization of the trigger unit of a six-rod TVS. The different configurations of the trigger pin and of the trigger electrode have been considered to study the electric field distribution at the triple points of the unit embedded in the cathode. To optimize the field enhancement, electric field simulations with a planar and a circular heads of the trigger pin in combinations with a convex and a concave shaped trigger electrodes have been done. The simulations were done with an applied trigger pulse voltage of Utrigger = 5 kV and with a discharge voltage the main switch of Uswitch = 20 kV. The experimental values had been Utrigger = 40 kV and Uswitch = 5 kV. The simulation results show that the combination of a circular trigger pin head and a concave trigger electrode yields the highest electric field of 9.6 .106 V/m at the triple point. In-parallel experiments have been performed with those four trigger configurations. The results of the experiments however cannot yet clearly confirm the trend in the results of the field simulations. 
Wung-Hoa Park, Moo-Sang Kim, Yoon-Kyoo Son, Klaus Frank, Byung-Joon   Lee
physics.ins-det physics.plasm-ph