Influence of Self-Generated Fields on Hot Electron Transport in NIF Hohlraums

Benjamin Reichelt, Massachusetts Institute of Technology

Photo of Benjamin Reichelt

In ICF hohlraums, high laser intensities drive multiple types of instabilities capable of accelerating electrons to supra-thermal velocities. These hot electrons interact with the hohlraum plasma and walls to produce hard x-ray bremsstrahlung emission that can be seen in various diagnostics like NIF’s FFLEX. Hot electrons in the hohlraum can be confined by spontaneously generated magnetic fields within the hohlraum plasma and result in x-ray spectra with features that give information about the evolution of magnetic and electric fields within the hohlraum. Dewald et al. [PRL 116, 075003 (2016)] have shown that for medium gas fill hohlraums during the picket pulse, electrons are deposited as though they were emitted in a beaming configuration. In this work, we develop a model to consider the influence of self-generated electromagnetic fields on the transport of electrons in order to explain anomalous phenomena seen by Dewald et al. as well as time resolved spectral information.

Abstract Author(s): Benjamin Reichelt(1), Jacob Pearcy(1), Eduard Dewald(2), Otto Landen(2), Matthias Hohenberger(2), Sean Regan(3), Richard Petrasso(1), and Chikang Li(1). (1)Massachussetts Institute of Technology; (2)Lawrence Livermore National Laboratory; (3)Laboratory for Laser Energetics