Secondary DT neutron spectra in magnetized indirect-drive implosions*

Diagnosing plasma magnetization in inertial-confinement-fusion (ICF) implosions is important for understanding how magnetic fields affect implosion dynamics.  Secondary deuterium-tritium (DT) reactions provide two diagnostic signatures to infer neutron-averaged magnetization.  Magnetically confining fusion tritons from deuterium-deuterium (DD) reactions in the hot spot increases their path lengths and energy loss, leading to an increase in the secondary DT reaction yield.  In addition, the distribution of magnetically-confined DD-triton is anisotropic, and this drives anisotropy in the secondary DT-neutron spectra along different lines of sight.  Neutron spectra from magnetized and unmagnetized indirect-drive implosions at the National Ignition Facility (NIF) will be discussed.