Cross section measurements to address the electron screening problem

High-energy-density plasmas are an excellent surrogate for astrophysical conditions under which nucleosynthesis occurs. One important phenomenon which occurs in these plasmas is modified electron screening, which affects stellar rates by tens of percent for some reactions. Accelerator data at low energies must be corrected for bound-electron screening to obtain bare cross sections, before plasma screening models are applied for stellar conditions; in some experiments, notable discrepancies between bound-screening models and the data are observed [M. Aliotta et al., Nucl. Phys. A 690, 790 (2001)]. Here we use inertial fusion implosions at the National Ignition Facility to create low-temperature plasmas with negligible screening to study the D+3He fusion reaction at center-of-mass energies where bound-electron screening, in accelerator measurements, is significant. This methodology can produce results novel for understanding the bound-electron screening, and is a prelude to future experiments studying plasma screening.

This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

LLNL-ABS-836271