Gamma-gamma directional correlations in Rh 105

Abstract

Directional correlation measurements have been made on the 320–475 keV and 485-475 keV gamma-gamma cascades in Rh 105 following the decay of 4.5 h half-life Ru 105 with a coincidence scintillation spectrometer using NaI detectors. The observed correlation functions are W(θ) = 1+(0.035±0.005)P 2(cosθ)−(0.017±0.004)P 4(cosθ), W(θ) = 1+(0.171±0.016)P 2(cosθ)−(0.137±0.004)P 4(cosθ) respectively, for the two cascades. These gamma-gamma directional correlations have been found to be consistent with the spin assignment of 7 2 , 7 2 , 5 2 and 7 2 to the levels at the ground state, 475 keV, 795 keV and 960 keV in Rh 105. The probable assignment of multipolarities for different gamma rays is as follows: The 475 keV gamma ray has a mixture of (30–55)% dipole and (45–70)% quadropole, with δ 475 = 0.904 − +1.527. The 485 keV gamma ray has a mixture of (0–20)% dipole and (80–100)% quadrupole, with δ 485 ≧ +2.0 . The 320 keV gamma ray has a mixture of (95–96.5)% dipole and 3.5–5)% quadrupole, with δ 320 = +0.191 − +0.230.