Enhanced Hot Electron Preheat Observed in Magnetized Laser Direct-Drive Implosions
Abstract
Hard x-ray emission, associated with hot electron preheat, in direct-drive implosions was observed to be enhanced by a factor of by application of a T magnetic field. The applied magnetic field reaches a quasi steady-state aligned with the ablation flow prior to the onset of laser-plasma instabilities in the corona. Hot electrons that would otherwise escape the corona and lead to capsule charging in unmagnetized implosions are confined in a mirror-mode of the magnetic field in magnetized implosions. These hot electrons are shown to subsequently pitch-angle scatter from the mirror onto the capsule, thereby leading to the observed hard x-ray generation in magnetized implosions. Consequently, the energy of charged-fusion products, associated with the capsule charging, are observed to decrease when the implosion is magnetized. These results intensify the need to mitigate laser-plasma instabilities -- particularly for magnetized implosions -- to maximize fusion gain and implosion efficiency.
Cite
@article{arxiv.2602.16884,
title = {Enhanced Hot Electron Preheat Observed in Magnetized Laser Direct-Drive Implosions},
author = {M. Cufari and M. Gatu Johnson and C. K. Li and J. A. Frenje and P. W. Moloney and A. J. Crilly and P. V. Heuer and J. R. Davies},
journal= {arXiv preprint arXiv:2602.16884},
year = {2026}
}