He*

This experiment provides the first data for exclusive three-body
photodisintegration of ³He at low energy (15 MeV). These data will be used to
evaluate ab-initio ³He photodisintegration calculations in highly constrained
regions of kinematic phase space. The cross section in the region of the
neutron-proton 1S0 final-state interaction will be used to examine the
theoretical treatment based on dynamics which include pairwise nucleon-nucleon
potential, three-nucleon interaction, the Coulomb force, and meson-exchange
currents.
Neutron-proton, proton-proton, and proton-deuteron coincidences are measured. The
two-body reaction is simultaneously recorded to monitor the target-beam luminosity.
The energy of the emitted charged particles is measured with silicon strip
detectors, and the emission angles of the charged particles are constrained by
collimation. The energy of the neutron is determined by time of flight. A
discussion of the experiment and preliminary results will be presented.