Measurement of emitted tritons and 3Helium from 112,124Sn+112,124Sn collisions at Ebeam=50 MeV/ nucleon and 120 MeV/nucleon*

The nuclear symmetry energy affects many aspects of nuclear structure, nuclear astrophysics, and nuclear reactions. The spectral ratio of neutrons to protons from central heavy ion collisions is sensitive to the symmetry energy below saturation density, but is difficult to measure. t/3He ratios, however, provide an easier measurement, since neutron detection efficiency is not an issue. A recent experiment at NSCL/MSU has measured n/p ratios from collisions of 112,124Sn+112,124Sn at Ebeam=50 MeV/nucleon. In addition, t/3He ratios were measured at the same time. First results of the t/3He double ratios as well as systematic studies of theoretical calculations of n/p and t/3He double ratios will be discussed.