TENMAK D.N.3326 In recent years, the 1001 keV gamma ray emission from 234mPa as an analytical peak is commonly used in the direct gamma ray spectrometric measurements of 238U content. 234mPa is the second daughter of 238U and rapidly reaches secular equilibrium with parent nucleus. This “clean” peak is well resolved by high purity Ge detectors and gives more accurate indication of uranium content without requiring any self attenuation correction. Several experimental results for the absolute emission probability of the 1001 keV gamma ray of 234mPa have resulted in doubts concerning the old recommended value of 0.59±0.01% obtained by following a radiochemical separation method. Therefore, this old value is now obsolete and a newly value of 0.835±0.004% is recommended. In this study the gamma-ray spectrometric measurements for the determination of the absolute emission probability of the 1001 keV gamma ray of 234mPa were carried out using the powdered uranium samples. A new experimental value of 0.861±0.015% for the absolute gamma ray emission probability for the 1001 keV gamma ray of 234mPa has been obtained. The present measured value agrees within 2.5 to 4% with the most recent experimental results appeared in the literature and the newly recommended value of the absolute emission probability for the 1001 keV gamma-ray of 234mPa. However, it is different from the latest experimental value of 0.92±0.02%, obtained by Anilkumar et al. (1999). Turkish Atomic Energy Authority, [v.d.]….
