Description
The STEREO experiment aims at measuring accurately the antineutrino spectrum [1,2] emitted by the ILL research reactor, for a complete study of the Antineutrino Reactor Anomaly [3]. Installed at 10 m from the core, the target volume of the detector [4] is filled with a Gd-loaded organic liquid scintillator in order to sign the capture of the neutron produced by a neutrino interaction. The compactness of the target makes the detection efficiency of this neutron heavily relying on the description of the de-excitation of Gd isotopes. Therefore, the FIFRELIN [5,6] code has been coupled with the GEANT4 simulation of the STEREO experiment for a significant improvement of the Data/MC agreement [7]. In this work we present the implementation of several new ingredients in the FIFRELIN code: the primary γ ray intensities from the EGAF [8] database, the physics of angular correlations between the de-exciting γ rays [9] and the treatment of X rays that follow the decay via conversion electrons. An output of these improved simulations will be made available soon to the community. Applications to a wider range of isotopes, of interest for neutrino and dark matter physics will be discussed.
Keywords neutron-capture, γ-cascade
Acknowledgements
We acknowledge the financial support of the Cross-Disciplinary Program on Numerical Simulation of CEA, the French Alternative Energies and Atomic Energy Commission.
References
[1] H Almazán et al., J. Phys. G: Nucl. Part. Phys. 48 075107 (2021)
[2] H Almazán et al., Phys. Rev. Lett. 125 201801 (2020)
[3] T.A. Mueller et al., Phys. Rev. C 83 054615 (2011)
[4] N. Allemandou et al., JINST 13 P07009 (2018)
[5] O. Litaize et al., Nuclear Data Sheets 118, 216 (2014)
[6] O. Litaize et al., Eur.Phys. J. A 51 1 (2015)
[7] H. Almazán et al., EPJ A 55 183 (2019)
[8] Evaluated Gamma Activation File, https://www-nds.iaea.org/pgaa/egaf.html (accessed: 2021)
[9] A. Chalil et al., Eur. Phys. J. A 58 30 (2022)
| Collaboration | STEREO |
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