Measurement of the 171Tm beta spectrum

Frédéric Juget; Maarten van Dijk; Emilio Andrea Maugeri; Maria Dorothea Schumann; Stephan Heinitz; Alexey Boyarsky; Ulli Köster; Lesya Shchutska; Claude Bailat

doi:10.1016/j.apradiso.2023.111058

Measurement of the ¹⁷¹Tm beta spectrum

Appl Radiat Isot. 2023 Dec:202:111058. doi: 10.1016/j.apradiso.2023.111058. Epub 2023 Sep 27.

Authors

Frédéric Juget¹, Maarten van Dijk², Emilio Andrea Maugeri³, Maria Dorothea Schumann³, Stephan Heinitz⁴, Alexey Boyarsky⁵, Ulli Köster⁶, Lesya Shchutska², Claude Bailat⁷

Affiliations

¹ Institute of Radiation Physics, Lausanne, Switzerland. Electronic address: Frederic.Juget@chuv.ch.
² Laboratoire de Physique des Hautes Energies, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
³ Paul Scherrer Institute, Villigen, Switzerland.
⁴ Belgian Nuclear Research Center, Mol, Belgium.
⁵ Laboratoire de Physique des Hautes Energies, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland; Instituut Lorentz, Leiden University, Leiden, the Netherlands.
⁶ Institut Laue-Langevin, Grenoble, France.
⁷ Institute of Radiation Physics, Lausanne, Switzerland.

PMID: 37797449
DOI: 10.1016/j.apradiso.2023.111058

Abstract

The beta spectrum of the main transition of the β^- 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 ξ-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.

Keywords: (171)Tm; Beta spectrum measurement; End-point energy; Kurie plot; Magnetic spectrometer.