Test and application of a symmetrical four-detector Compton polarimeter for low temperature nuclear orientation and in-beam spectroscopy

Abstract A symmetrical four Ge detector Compton polarimeter was used to measure the linear polarization of γ-rays emitted from nuclei oriented by the hyperfine interaction at low temperature by using the UNISOR/NOF 3 He 4 He dilution refrigerator. Its polarization detection efficiency was determined over the energy range 0.3–1.4 MeV, and is higher than those of other known polarimeters. It was used to measure the polarization of γ-rays in 186 Hg observed in-beam.