Proton radiography of dynamic electric and magnetic fieldsin laser-produced high-energy-density plasmas

摘要

Time-gated, monoenergetic-proton radiography provides unique measurements of the electric (E)and magnetic (B) fields produced in laser-foil interactions and during the implosion ofinertial-confinement-fusion capsules. These experiments resulted in the first observations of severalnew and important features: (1) observations of the generation, decay dynamics, and instabilities ofmegagauss B fields in laser-driven planar plastic foils, (2) the observation of radial E fields insidean imploding capsule, which are initially directed inward, reverse direction during deceleration, andare likely related to the evolution of the electron pressure gradient, and (3) the observation of manyradial filaments with complex electromagnetic field striations in the expanding coronal plasmassurrounding the capsule. The physics behind and implications of such observed fields arediscussed.