Assessment and mitigation of electromagnetic pulse (EMP) impacts at short-pulse laser facilities

Abstract

The National Ignition Facility (NIF) will be impacted by electromagnetic pulse (EMP) during normal long-pulse operation, but the largest impacts are expected during shortpulse operation utilizing the Advanced Radiographic Capability (ARC). Without mitigation these impacts could range from data corruption to hardware damage. We describe our EMP measurement systems on Titan and NIF and present some preliminary results and thoughts on mitigation.

Analysis of electromagnetic pulse (EMP) measurements in the National Ignition Facility's target bay and chamber

“…An advanced diagnostic system planned for NIF, the Advanced Radiographic Capability (ARC), requires shorter pulse durations in the 1 to 10 ps range. Based on results presented here and data from our work at the short-pulse Titan laser facility [5,6], we expect the EMP on NIF to increase significantly during ARC operation. We fielded similar EMP sensors in NIF's target bay and chamber that we used earlier on Titan.…”

“…However, it is not possible to completely shield any diagnostic and still obtain the needed data. In addition, our work on the Titan short-pulse laser showed that the EMP can extend out to higher frequencies (5 GHz and above) [5,6], which is higher than NIF's original design specification for shielding. This provided motivation to measure EMP on NIF prior to full energy operation to measure energy scaling and to also determine if some targets produced larger EMP.…”

“…See [1][2][3][4][5][6] for previous work on EMP in laser facilities. The National Ignition Facility (NIF) is the world's largest laser with up to 1.8 MJ of 3 laser energy.…”

Investigation into the electromagnetic impulses from long-pulse laser illuminating solid targets inside a laser facility

“…Brown et al [5] at Lawrence Livermore National Laboratory installed multiple B-and D-dot sensors in the Titan short-pulse laser facility (ps) to measure the levels of electromagnetic fields, by which the electric field strength from the sensors locating about 32 cm from target chamber center was estimated to be 167 kV/m. During this process, the ps and ns laser pulses generated quite different ion emission current densities, leading to up to 100 MeV by sub-picosecond laser plasma [6].…”

Directional Track Selection Technique in CR39 SSNTD for lowyield reaction experiments

“…These detectors are widely used in different fields and are fundamental in environments heavily affected by electromagnetic radiation of high intensity, where active electronic detectors will be not applicable [2][3][4]. In particular, they are the key diagnostics in investigation of low-yield nuclear reactions, such as the neutron-less p-11 B reactions generated by laser-matter interaction [5][6][7][8][9][10][11][12].…”