Effective atomic number of some rare earth compounds determined by the study of external bremsstrahlung

In this paper we report the effective atomic number (Zeff) of some rare earth compounds determined from the measured external bremsstrahlung (EB) intensity due to the incident beta particles emitted by the 90Sr-90Y source. For this purpose the two sample method evolved recently by the authors was employed. A high purity germanium detector was used in the present study to improve the resolution of the detection system. The constants lnK, n, C and D for the present geometry and the detector were determined by using the EB intensity measured for the elemental foils Al, Cu, Ag, Sn and Pb of varying thickness. The Zeff values obtained were in good agreement with the Zmod values given by the theoretical expression of Markowicz and Van Grieken. Possible conclusions are drawn based on the present study.