Unfolding continuous photon spectrum emitted from Sr-90-Y-90 in equilibrium

This paper presents an experiment with the 2 x 2 inch NaI(Tl) detector to measure the internal bremsstrahlung of Sr-90-Y-90 in equilibrium beta particle emitters using the beta-stopper method in the range 10-1750 keV. The Gold algorithm is applied to unfold the internal bremsstrahlung spectrum of Sr-90-Y-90 beta source. Unfolded IB spectrum is compared with the KUB theory. There is good agreement between the theory and the unfolded measured spectrum in the energy range below 1000 keV. Beyond this energy, there are discrepancies between the theory and unfolded spectrum