  We investigate neutrino processes for conditions reached in simulations of
core-collapse supernovae. Where neutrino-matter interactions play an important
role, matter is partially degenerate, and we extend earlier work that addressed
the degenerate regime. We derive expressions for the spin structure factor in
neutron matter, which is a key quantity required for evaluating rates of
neutrino processes. We show that, for essentially all conditions encountered in
the post-bounce phase of core-collapse supernovae, it is a very good
approximation to calculate the spin relaxation rates in the nondegenerate
limit. We calculate spin relaxation rates based on chiral effective field
theory interactions and find that they are typically a factor of two smaller
than those obtained using the standard one-pion-exchange interaction alone.
