The beta spectrum of the main transition of the beta-decay of 171Tm was measured using a double focalizing spectrometer. The instrument was lately improved in order to reduce its low energy threshold to 34 keV. We used the spectrometer to measure the beta spectrum end-point energy of the main transition of 171Tm decay using the Kurie plot formalism. We report a new value of 97.60(38) keV, which is in agreement with previous measurements. In addition, the spectrum shape was compared with the xi-approximation calculation where the shape factor is equal to 1 and good agreement was found between the theory and the measurement at the 1% level.
@article{arxiv.2307.09870,
title = {Measurement of the 171Tm beta spectrum},
author = {Frédéric Juget and Maarten van Dijk and Emilio Andrea Maugeri and Maria Dorothea Schumann and Stephan Heinitz and Alexey Boyarsky and Ulli Köster and Lesya Shchutska and Claude Bailat},
journal= {arXiv preprint arXiv:2307.09870},
year = {2023}
}