Measurement of the absolute gamma-ray emission intensities from the decay of $^{147}$Nd

Abstract : The 2011 Decay Data Evaluation Project (DDEP) evaluation for $^{147}$Nd includes recommended absolute emission intensities for the two main gamma-rays at 91.105(2) keV and 531.016 (22) keV of 0.284(18) and 0.127(9) respectively, i.e. with uncertainties of 6.3% and 7.1%. Hence the LNE-LNHB has undertaken new absolute gamma-ray emission intensity measurements. The $^{147}$Nd source was produced at the TU Delft, Netherlands. The deposit was dissolved. To remove any possible impurities, a separation was undertaken using High Performance Liquid Chromatography directly coupled with an Inductively Coupled Plasma Mass Spectrometry. Absolute activity measurements were performed using two techniques before and after separation: the 4$\pi \beta \gamma$ coincidence method and the 4$\pi \gamma$ counting technique using a well-type NaI(Tl) detector. The gamma-ray intensities were measured before and after separation and give consistent results. The results of these measurements will be presented, along with a full uncertainty budget, and their effect on the recommended data uncertainties will be discussed.