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

Tao Yi,Shaoqiu Xiao,Chuanke Wang,Weiming Yang,Ming Yang,Yongkun Ding,Jinwen Yang,Tingshuai Li,Shenye Liu,Shaoen Jiang

doi:10.1007/s13320-016-0346-4

Abstract

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.

Highlights

Various radiations tend to be generated when some particles strike solid targets like Cu [1], the concentration of extremely powerful laser beams onto a solid target would induce significant electromagnetic radiation, which can not be only used for scientific research concerning the physics of extreme energy densities and pressures, and provide a feasible path to achieve inertial confinement fusion (ICF) and a promising way to generate carbon-free sustainable energy [2]
Each electromagnetic pulse (EMP) has transient duration of up to 80 ns before the signal attenuation decays into noise
All the wave forms show that there are some unfixable periods for EMP peaks, where oscillation of the waveforms can be observed with time course, and the time intervals of some evident peaks are assessed from several ns to dozens of ns

Summary

Introduction

Various radiations tend to be generated when some particles strike solid targets like Cu [1], the concentration of extremely powerful laser beams onto a solid target would induce significant electromagnetic radiation, which can not be only used for scientific research concerning the physics of extreme energy densities and pressures, and provide a feasible path to achieve inertial confinement fusion (ICF) and a promising way to generate carbon-free sustainable energy [2]. 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]. The fs laser pulse inducing EMP can be enhanced by a long (ns) laser pulse due to the formation of pre-plasma [9]

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Results

Conclusion