Studies of the hyperfine interaction of 111Cd in gaseous InCl and InCl3 systems

Using the perturbed γ-γ angular correlation at excited 111Cd-ions from the decay of 111In, the time-integral attenuation coefficient G22(∞) was measured in gaseous InCl and InCl3 surroundings. The perturbation depends as well on the character and the density of the surrounding gas, as on the angular momentum of the electronic shell of the Cd-ion. G22(∞) varied between 0.012 and 0.828, while the molecule densities varied between 2x1014 and 2x1020 molecules/cm3. For high densities it is to be noted, that the perturbation vanishes much faster for the InCl systems. Using a stochastic model, it is possible to calculate the mean hyperfine frequency ω0, and to estimate cross-sections for molecule-ion collisions at thermal energies. (orig.)