Search for variations of N22a decay constant

Jovana Knezevic; Dusan Mrdja; Kristina Bikit-Schroeder; Jan Hansman; Istvan Bikit; Jaroslav Slivka

doi:10.1016/j.apradiso.2020.109178

Search for variations of N22a decay constant

Appl Radiat Isot. 2020 Sep:163:109178. doi: 10.1016/j.apradiso.2020.109178. Epub 2020 May 5.

Authors

Jovana Knezevic¹, Dusan Mrdja², Kristina Bikit-Schroeder¹, Jan Hansman¹, Istvan Bikit¹, Jaroslav Slivka¹

Affiliations

¹ University of Novi Sad, Faculty of Science, Department of Physics, Trg Dositeja Obradovica 3, 21000, Novi Sad, Serbia.
² University of Novi Sad, Faculty of Science, Department of Physics, Trg Dositeja Obradovica 3, 21000, Novi Sad, Serbia. Electronic address: mrdjad@df.uns.ac.rs.

PMID: 32392163
DOI: 10.1016/j.apradiso.2020.109178

Abstract

Exploration of possible anomalies in the decay of different radionuclides is an active research area in the fields of astrophysics and nuclear physics. The most significant changes in decay rates can be expected for β^-, β⁺ or electron capture decay nuclides, due to the proposed influence of the solar neutrino flux by some research groups. In this work, the nuclear decay rate of β⁺ decay of N22a was investigated during the time interval of ~33 days. For this purpose, a coincidence system based on a planar high purity germanium detector and a plastic scintillation detector was designed and used for the acquisition of experimental N22a coincidence spectrum. The corresponding experimental conditions: temperature, atmospheric pressure, and relative humidity, which may affect the measurement system, were monitored. In addition, Monte-Carlo simulations of this system were performed in order to obtain the N22a simulated coincidence spectrum. The time-dependent coincidence spectra in 0.5 h bins were collected by the multiparameter MPA-3 system. The fluctuations in the decay rate (i.e. possible variations of the decay constant) were analyzed by Fourier and Lomb-Scargle algorithms. No significant evidence for periodic behavior in decay rate or aperiodic anomalies was found during the acquisition period.

Keywords: (22)Na decay constant fluctuations; Coincidence system; Lomb-scargle analysis; Monte-carlo simulations; Periodic behavior.