Direct Measurements of DT Fuel Preheat from Hot Electrons in Direct-Drive Inertial Confinement Fusion
Name
21ja079_full.pdf
Size
746.63 KB
Format
Adobe PDF
Checksum (MD5)
53948553cc9d2fa718a1aebf46945b33
Author(s)
Christopherson, A.R.
Betti, R.
Forrest, C.J.
Howard, J.
Theobald, W.
Delettrez, J.A.
Rosenberg, M.J.
Solodov, A.A.
Stoeckl, C.
Patel, D.
Date Issued
July 2021
Journal
Physical Review Letters
Publisher
APS
Abstract
Hot electrons generated by laser-plasma instabilities degrade the performance of laser-fusion implosions by preheating the DT fuel and reducing core compression. The hot-electron energy deposition in the DT fuel has been directly measured for the first time by comparing the hard x-ray signals between DT-layered and mass-equivalent ablator-only implosions. The electron energy deposition profile in the fuel is inferred through dedicated experiments using Cu-doped payloads of varying thickness. The measured preheat energy accurately explains the areal-density degradation observed in many OMEGA implosions. This technique can be used to assess the viability of the direct-drive approach to laser fusion with respect to the scaling of hot-electron preheat with laser energy.
Description
Submitted for publication in Physical Review Letters
MIT Department
Massachusetts Institute of Technology. Plasma Science and Fusion Center
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1103/physrevlett.127.055001
