Mitsuhiro Kawamura

Hyperfine Magnetic Field at Mercury in Ferromagnetic Iron

The perturbed angular correlations of 675 keV-412keV gamma-gamma cascade in Hg 198 were measured on the iron metal samples containing 0.2∼2 at % gold impurity magnetized up to saturation. The average value of the shifts of angular correlation pattern was obtained as |ωτ|=(0.049±0.009) radian. The hyperfine magnetic field at mercury in iron was found to be -(590±160) kOe, assuming the known value of mean life and g-factor of 412 keV level in Hg 198 . The multipole mixing of 675 keV transition was also obtained to be (60.6±2.5)% E 2 plus (\(39.4\mp 2.5\))% M 1.

Angular Correlation Measurements in the Decay of In114m

The directional correlation and the polarization direction correlation of the 722 Kev-556 Kev gamma-gamma cascade in Cd 114 have been measured. It is found that the decay sequence of this cascade agrees well with the 4(E2)2(E2)0 sequence. The ratio of the rate of the positron decay to that of the cascade decay is also obtained as 3×10 -3 .

The g-Factor of the First Excited Level of 196Pt

The perturbed angular correlations of 333.0 keV–355.7 keV gamma-gamma cascade in 196 Pt were measured on iron-gold alloy samples containing 0.2–0.5 at% gold impurity prepared by various thermal treatments. The shift of angular correlation pattern was obtained as ωτ=0.095 ±0.003 rad. The g -factor of the first excited level of 196 Pt was determined to be g =0.346 ±0.013.

The Decay Scheme of 91Sr

The decay scheme of 91 Sr was studied through the measurements of gamma-ray singles and coincidence spectra, gamma-gamma angular correlations and internal conversion coefficients. The energies and intensities of 49 gamma rays including 14 new ones were determined. A decay scheme of 91 Sr involving two new levels in 91 Y is proposed.

Excited States of Pt192

The directional correlations of the 300 kev-300 kev, 468 kev-316 kev and 300 kev-600 kev gamma-gamma cascades in Pt/sup 192/ have been measured by using the coincidence spectrometer reported previously. It is found that the spins of the 784 kev and 920 kev levels are 4 and 3, respectively. (auth)

Directional Correlation of the Ti46 Gamma-Gamma Cascade

The directional correlation of successive gamma-rays from Ti 46 was measured using RCA 5819 photomultiplier tubes with Nal(Tl) scintillation crystals as the detectors. The measurements were made by counting more than 50,000 genuine coincidence counts at each angle. It was found that the successive gamma-rays were both quadrupole and the spins of the ground, 1st and 2nd excited state should be 0.2 and 4, respectively.

The Second Excited State of Sn120

The directional correlation and the polarization-direction correlation of the 1.03 Mev–1.17 Mev gamma-gamma cascade in Sn 120 have been measured. It is found that the spin and the parity of the second excited state of Sn 120 is 4 and even, respectively.