Determination of solid angle corrections for precise gamma-gamma directional correlation experiments with Ge-detectors

Abstract

An experimental method is described to determine angle dependent attenuation factors due to the finite solid angle in gamma-gamma directional correlations with Ge-detectors. The correction factors have been calculated a.o. for the 622-512 keV (0 +−2 +−0 +) cascade in 106Pd. Data from a correlation experiment on this cascade have been fitted to the factors and produced A 2 and A 4 anisotropy coefficients within 1% of the theoretical values. Angle independent correction factors obtained from Monte-Carlo calculations and from a horizontal scan method have been used in a comparison with the mentioned results. This comparison has shown that differences of more than 10% can arise by using these methods. An extended measurement yielded A 2 and A 4 coefficients for the (0 +−2 +−0 +) cascade in 106Pd. The values are: A 2 = 0.356(2) and A 4 = 1.143(3), very close to the theoretical ones.