Laser-driven quasi-static B-fields for magnetized high-energy-density experiments

Abstract

We present measurements of magnetic Ąelds generated in laser-driven coil targets irradiated by laser pulses of nanosecond-duration, 1.053 µm wavelength, 500 J energy and ∼ 1015 W/cm2 intensity, at the LULI2000 facility. Using two perpendicular probing axes, proton deflectometry is used to characterize the coil current and static charge at different times. Results reveal various deflection features that can be unambiguously linked to a looping quasi-steady current of well understood polarity or to a static charging of the coil surface. Measured currents are broadly consistent with predictions from a laser-driven diode-current source and lumped circuit model, supporting the quasi-steady assessment of the discharges. Peak magnetic Ąelds of ∼ 50 T at the center of 500 µm diameter coils, obtained at the moderate laser intensity, open up the use of such laser-driven coil targets at facilities worldwide to study numerous phenomena in magnetized high energy-density plasmas, and its potential applications.