Abstract:

K-X-ray-γ directional correlations following the decay of54Mn,65Zn,75Se,85Sr,133Ba and207Bi have been performed. The experimental set-up consisted of a set of four scintillation counters, one for detecting X-rays and the three others for detecting γ-rays, placed at 90°, 180° and 270° with respect to the source to X-ray detector direction. Multiple coincidence units and a logic system were used in order to display three X-ray spectra in three 128-channel submemories of a 512-channel analyser, corresponding to coincidences between X-rays and γ-rays detected in each counter, respectively. For the case of the133Ba X-γ angular correlation, the scintillation counters were replaced by one Ge(Li) detector in order to select with high resolution the γ-ray of 356 keV. Corrections for chance coincidences were made and a χ2-test of the data was performed. From the K-X-γ directional correlations following the above-mentioned decays a value of the anisotropy was derived. In all cases this value is consistent with zero, to within a one percent error. These results are in agreement with the theoretical predictions of Dolginov. A discrepancy with the anisotropy value reported by Perepelkin appeared. The values corresponding to the decays of65Zn,85Sr and133Ba are consistent with the ones reported by Ramaswamy and McDonnell and Ramaswany. © 1971 Società Italiana di Fisica.