Electro-optical measurement of intense electric field on a high energy pulsed power accelerator

Abstract

We describe a direct electro-optical approach to measuring a strong 118 MV/m narrow pulse width (~ 33 ns) electric field in the magnetically insulated transmission line (MITL) of a pulsed power accelerator. To date, this is the highest direct external electric field measured electro-optically in a pulsed power accelerator, and it is between two to three orders of magnitude higher than values reported in comparable high energy scientific experiments. The MITL electric field is one of the most important operating parameters in an accelerator and is critical to understanding the properties of the radiation output. However, accurately measuring these high fields using conventional pulsed power diagnostics is difficult due to the strength of interfering particles and fields. Our approach uses a free-space laser beam with a dielectric crystal sensor that is highly immune to electromagnetic interference and does not require an external calibration. Here we focus on device theory, operating parameters, laboratory and pulsed power accelerator experiments as well as challenges that were overcome in the measurement environment.

Experimental results of a 330 GW impedance-matched Marx generator

“…IMGs are the most advanced pulsed-power drivers and are being considered for the NGPP facilities 1,2 , pulsed-power accelerators 23 , flash x-ray and gamma-ray sources [23][24][25][26] , high-energy lasers (HEL) 27 , high-power microwaves (HPM) 28,29 , excimer lasers 27 , materials under extreme conditions 30,31 , high-energy density plasmas 9,[32][33][34] , radiation and nuclear effects 23,35 , national security research, and inertial confinement fusion 8,32,36 .…”

Electro-optic Bdot probe measurement of magnetic fluctuations in plasma

“…The Pockels effect 8 is an electro-optic effect and has been utilized for the direct measurements of electric fields, such as microwaves and high-voltage phenomena. [9][10][11][12][13][14][15] In the field of plasma physics, examples of successful electric field measurement using electro-optic sensors include the validation of anomalous resistance brought on by the chaotic motion of charged particles, 10 diagnostics in an ion thruster, 11 and direct detection of…”