MAGNETIC COMPTON PROFILE MEASUREMENT USING CIRCULARLY POLARIZED GAMMA-RAYS FROM ORIENTED IR-191M NUCLEI

Circularly polarized 129 kev gamma -rays from oriented **1**9**1**mIr nuclei are used to measure the Compton profile of magnetic electrons in ferromagnetic iron. A high degree of circular polarization is obtained even at temperatures about 200 mK owing to the large hyperfine magnetic field at the Ir site in Fe metal. Utilization of a 40 mCi gamma -ray source, together with a **3He/**4He dilution refrigerator and a solid state detector, is found to be effective in obtaining high statistical accuracy. Efficient geometrical arrangement of the apparatus is discussed based on the cross section of the spin-dependent Compton scattering. Experimental procedures, source preparation and data accumulation are described in detail.