Photodisintegration of the Deuteron by Polarized Gamma Rays

An experiment has been performed on the photodisintegration of the deuteron by linearly polarized $\gamma$ rays in the energy range from 200 to 400 MeV. The polarization is obtained by the crystal technique and is generally of the order of 30 to 40%. Both the neutron and the proton are detected in coincidence in order to reduce the background drastically. The asymmetry parameter at 90° in the center-of-mass system has been determined as a function of the energy $k$ of the photon; it depends very little on $k$ and has a value close to -0.3 all over the range.