At Crust09: PREX

Yesterday, during the general discussion, Chuck Horowitz mentioned that the lead radius experiment (PREX) will become operative in March 2010. This experiment will probe sub-nuclear densities and aims at constraining the symmetry energy term in the nuclear mass, which plays an important role in setting the structure and composition of neutron stars. For example, the symmetry energy term relates to the proton fraction in the core, which sets the threshold mass for the onset of direct Urca neutrino emission. This sounds like an exciting prospect!