CIRCULAR POLARIZATION OF NEUTRON-CAPTURE GAMMA RAYS FROM 23NA AND 31P

The circular polarization of γ-rays following the capture of polarized thermal neutrons in a target of23Na and31P was measured. The degree of polarization yielded the spin I=2+ for the 0.563 MeV level of24Na. For the 6.53 MeV γ-transition from the compound state to the 0.563 MeV level the mixing ratio δ=0.26-0.100.14 between E2 and M1 radiation was deduced. The measurement is consistent with the spinvalue I=2+ of the 2.95 keV resonance for thermal neutron-capture of24Na. For32P we confirmed the earlier spin assignement I=1+ for the 1.149 MeV level. An upper limit 0<δ<0.15 for the mixing ratio of the 6.8 MeV capture-γ-transition was established. © 1968 Springer-Verlag.