Directional Correlation of Gamma Rays Following the Decay ofEu152

Abstract

Directional correlation measurements have been made on the 245 kev-122 kev, 969 kev-122 kev, 1118 kev-122 kev, 1416 kev-122 kev, 872 kev-245 kev, and 1170 kev-245 kev cascades in ${\mathrm{Sm}}^{152}$, and on the 782 kev-345 kev cascade in ${\mathrm{Gd}}^{152}$. The spins of ${\mathrm{Sm}}^{152}$ are found to be 0, 2, 4, 2, 3, 3, for the ground, 122-kev, 367-kev, 1092-kev, 1240-kev, and 1538-kev levels. The 245-kev gamma ray is found to be pure quadrupole; the 872-kev gamma ray is 98% quadrupole, 2% dipole; the 969-kev gamma ray is 98% quadrupole, 2% dipole; the 1118-kev gamma ray is 99.8% quadrupole, 0.2% dipole; the 1170-kev gamma ray is 98% quadrupole, 2% dipole; the 1416-kev gamma ray is 15% quadrupole, 85% dipole. In ${\mathrm{Gd}}^{152}$ the spin of the 1127-kev level is found to be 3 and the 782-kev gamma ray is found to be pure dipole. A spin assignment of 1, 2, or 3 for the 757-kev level would not be inconsistent with the data. For any of these cases the 412-kev gamma ray must be mostly dipole; the quadrupole content must be less than 15%.