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

Abstract

Emission of the electromagnetic pulses (EMP) due to laser-target interaction in laser facility had been evaluated using a cone antenna in this work. The microwave in frequencies ranging from several hundreds of MHz to 2 GHz was recorded when long-pulse lasers with several thousands of joules illuminated the solid targets, meanwhile the voltage signals from 1 V to 4 V were captured as functions of laser energy and backlight laser, where the corresponding electric field strengths were obtained by simulating the cone antenna in combination with conducting a mathematical process (Tiknohov Regularization with L curve). All the typical coupled voltage oscillations displayed multiple peaks and had duration of up to 80 ns before decaying into noise and mechanisms of the EMP generation was schematically interpreted in basis of the practical measuring environments. The resultant data were expected to offer basic know-how to achieve inertial confinement fusion.

Spatial and temporal evolution of electromagnetic pulses generated at Shenguang-II series laser facilities

“…The EMP amplitude was approximately proportional to r 1 2 / when electromagnetic waves propagated inside the target chamber (vacuum) [10], where r was the distance from the measuring location to the TCC. Compared to the electromagnetic wave proceeding inside the target chamber, there are many objects outside the target chamber such as laser facility diagnostic devices and concrete walls that can adsorb or scatter EMPs, so EMP outside the target chamber will degrade at a much faster rate [29], which can be verified by the multiple shielding layers of 0.5 mm PTFE, 0.4 mm copper film and 2.4 mm lead [30] that attenuate EMP amplitude over 448 times.…”

Laser produced electromagnetic pulses: generation, detection and mitigation

“…Studies of EMP generation in this facility by using nanosecond beams have been reported in Refs. [104][105][106]. An experiment carried out on SG-II-UP, with ps laser pulses with energy of a few hundred joules, is described here.…”

Measurement of the electric field strength generated in the experimental chamber by 10 TW femtosecond laser pulse interaction with a solid target

“…With the advent of the petawatt power and megajoule energy laser facilities a systematic effort was made to study the EMP phenomenon [2][3][4][5][6][7]. Despite these efforts a full quantitative understanding of this effect has not yet been attained and the problem continues to attract attention [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22], with the interest driven by the fact that several multi-PW short-pulse laser facilities -such as the Extreme Light Infrastructure lasers in Prague, Szeged and Bucharestwould come online in near future.…”