A SECTORED GE-COMPTON POLARIMETER FOR PARITY ASSIGNMENTS IN PHOTON SCATTERING EXPERIMENTS

Parities of nuclear levels excited in photon scattering experiments ca n be determined by measurements of the linear polarization of the scat tered photons. The needed theoretical formalism is summarized. A fourf old sectored single crystal Ge-Compton polarimeter, its operation and performances are described. The compact polarimeter has an outstanding coincidence efficiency epsilon(coinc) of about 25% and a goad energy resolution of 2.2 keV at 1.333 MeV. The polarization sensitivity of th e device as determined in (gamma, <($) over right arrow gamma>) polari zation correlation measurements and several (p, p'<($) over right arro w gamma>) reaction studies amounts to about 20% at photon energies of 0.5 MeV and is about 10% at 4 MeV photon energies. The polarimeter has been successfully operated in systematic photon scattering experiment s at the bremsstrahlung beam at the Stuttgart Dynamitron facility to i nvestigate enhanced magnetic and electric dipole excitations in heavy deformed nuclei. Typical results are shown and discussed.