Detour effects on inner Bremsstrahlung from 91Y

Contribution of detour transitions to internal bresstrahlung (IB) is estimated using the recent calculations of Ford and Martin. The IB spectrum of 91Y is measured by using a multichannel NaI(Tl) scintillation spectrometer with a standard geometrical arrangement. After effecting all the necessary corrections, the total yields of intensity and of energy of IB are determined and compared with the corresponding theoretical (detour and direct) values of Ford and Martin in the investigated energy region from 100 to 1250 keV. The present experimental results are almost coinciding with the detour corrected theory in the energy region from 200 to 600 keV and below 200 keV and above 650 keV, the experiment is deviating positively from even this detour theory. The divergence between experiment and theory is found to increase with increasing energy. (author)