External bremsstrahlung of 90Sr–90Y, 147Pm and 204Tl in detector compounds

External Bremsstrahlung spectra produced by the complete absorption of beta particles from 90Sr to 90Y, 147Pm and 204Tl in nuclear radiation detection compounds like Cesium iodide (CsI) and Sodium Iodide (NaI) has been measured using 0.038 m×0.038 m NaI(Tl) crystal and is compared with Tseng–Pratt theory. The Bremsstrahlung yields are calculated using the unfolded spectra. This paper also describes a new procedure for the calculation of effective absorption coefficient of Bremsstrahlung from the Bremsstrahlung spectra. The measured spectra show fairly good agreement at low energy end of spectrum and some deviation at higher energy end of spectrum with the theory. The measured Bremsstrahlung yields may be useful to apply corrections, whenever beta particle passes through CsI and NaI detectors.

► Bremsstrahlung spectra of 90Sr–90Y, 147Pm and 204Tl in compounds CsI and NaI has been measured.
► This paper also describes a new procedure for the calculation of attenuation coefficient Bremsstrahlung.
► The measured yields may be useful to apply corrections for CsI and NaI detectors.