Precision measurement of $\beta$-spectra of $^{144}{\rm{Ce}}-^{144}{\rm{Pr}}$ nuclei.

Oct 14, 2020, 6:10 PM
1h
Online

Online

Poster report Section 5. Neutrino physics and astrophysics. Poster session 5

Speaker

Dr Valentina Muratova (Petersburg Nuclear Physics Institute NRC KI)

Description

Precision measurements of $\beta$-spectra have always been and are still playing an important role in several fundamental physical problems, predominantly in neutrino physics. In Petersburg Nuclear Physics Inst. NRC KI, the $\beta$-spectra of $^{144}{\rm{Ce}}-^{144}{\rm{Pr}}$ nuclei were measured with aim to determine the spectrum of electron antineutrinos. The artificial source of antineutrinos $^{144}{\rm{Ce}}-^{144}{\rm{Pr}}$ is one of the most promising for the experiments on the search for neutrino oscillations to the sterile state [1]. Several $\beta$-spectrometers based on silicon detectors have been developed. The first $\beta$-spectrometer, based on full absorption Si(Li) detector and thin transmission detector, allows to perform efficient separation $\beta$-radiation and accompanying X-rays and $\gamma$-radiation [2,3].
A new $\beta$-spectrometer was created from two Si(Li) detectors with a sensitive region thickness of more than 8 mm [4]. The response function of such a spectrometer for electrons with an energy of less than 3 MeV is almost Gaussian. The setup includes a 3" BGO detector for detecting gamma rays in order to select the decays of $^{144}{\rm{Ce}}-^{144}{\rm{Pr}}$ nuclei into excited levels of daughter nuclei. As a result, the beta spectra of $^{144}{\rm{Ce}}-^{144}{\rm{Pr}}$ nuclei were measured and the spectra of electron antineutrinos corresponding to $\beta$-transitions to the main and excited states. The measured form of the allowed $\beta$-transition is completely consistent with theoretical calculations. The created spectrometer with a response function close to Gaussian practically solves the problem of determining the spectrum of electronic antineutrino arising in the $\beta$-decay of $^{144}{\rm{Pr}}$ nuclei. The spectrometer can also be used in precision measurements of the spectrum shape of various radioactive nuclei.
This work was supported by the Russian Science Foundation (project nos. 17-12-01009) and by the Russian Foundation for Basic Research (project nos. 16-29-13014, 19-02-00097 and 20-02-00571).

[1] A.V. Derbin, I.S. Drachnev, I.S. Lomskaya, V.N. Muratova, N.V. Pilipenko, D.A. Semenov, E.V. Unzhakov, Monte-Carlo sensitivity study for sterile neutrino search with $^{144}{\rm{Ce}}-^{144}{\rm{Pr}}$ source and liquid scintillation detectors of various geometries, arXiv:1905.06670 (2019 г.)
[2] I.E. Alexeev, S.V. Bakhlanov, N.V. Bazlov, E.A. Chmel, A.V. Derbin, I.S. Drachnev, I.M. Kotina, V.N. Muratova, N.V. Pilipenko, D.A. Semenov, E.V. Unzhakov, V.K. Yeremin, Beta-spectrometer with Si-detectors for the study of $^{144}{\rm{Ce}}-^{144}{\rm{Pr}}$ decays, Nuclear Inst. and Methods in Physics Research, A 890 (2018) 64–67
[3] N.V. Bazlov, S.V. Bakhlanov, A.V. Derbin, I.S. Drachnev, V.K. Eremin, I. M. Kotina, V.N. Muratova, N.V. Pilipenko, D.A. Semenov, E.V. Unzhakov, E.A. Chmel, A Beta Spectrometer Based on Silicon Detectors, Instruments and Experimental Techniques, 2018, Vol. 61, No. 3, pp. 323–327
[4] S. Bakhlanov, A. Derbin, I. Drachnev, I. Kotina, I. Lomskaya, V. Muratova, N. Niyazova, D. Semenov, E. Unzhakov, 4$\pi$ semiconductor beta-spectrometer for measurement of 144Ce { 144Pr spectra, Journal of Physics: Conference Series 1390 (2019) 012117

Primary authors

Dr Valentina Muratova (Petersburg Nuclear Physics Institute NRC KI) Igor Alekseev (V.G. Khlopin Radium Institute) Sergey Bakhlanov (Petersburg Nuclear Physics Institute NRC KI) Alexander Derbin (Petersburg Nuclear Physics Institute NRC KI) ilia Drachnev (Petersburg Nuclear Physics Institute NRC KI) Irina Kotina (Petersburg Nuclear Physics Institute NRC KI) Mrs Irina Lomskaya (Petersburg Nuclear Physics Institute NRC KI) Nelly Niyazova (Petersburg Nuclear Physics Institute NRC KI) Dmitrii Semenov (Petersburg Nuclear Physics Institute NRC KI) Evgeniy Unzhakov (Petersburg Nuclear Physics Institute NRC KI)

Presentation materials