Laser Triggered Switch Results from a Frequency Quadrupled Nd:Yag Laser

A 3 MV modified PBFA trigatron switch has been successfully triggered by the 266 nm UV beam of a NdYAG laser in a water-insulated transmission line test facility. Focusing the 2 ns FWHM 25 plus or minus 5 mJ laser pulse into the 65 psig SF 6 atmosphere, triggered the switch gap from 69 to 90 of the self-break voltage VSB 2.3 MV. The characteristic linear slope is less than 5 ns per 10 of VsB with closure delay times less than those of the 20 ns KrF laser at twice the energy. Two data points deviating from the rest of the set increased the one-sigma jitter from 1.5 ns to 3.9 ns. More LTS data have been collected after the addition of a second trigatron which is also laser triggered. Jitters of 2.3 ns and 1.5 ns were measured for laser energies of 20 mJ or less. The initial implications are that a single 150 mJ NdYAG laser can satisfactorily trigger five or more switches to achieve low jitter between the modules of a particle accelerator as well as other large pulsed power devices.