- Access by Xinjiang University
Material Effects on Electron-Capture Decay in Cryogenic Sensors
Phys. Rev. Applied 19, 014032 – Published 10 January, 2023
DOI: https://doi.org/10.1103/PhysRevApplied.19.014032
Abstract
Several current searches for physics beyond the standard model are based on measuring the electron-capture (EC) decay of radionuclides implanted into cryogenic high-resolution sensors. The sensitivity of these experiments has already reached the level where systematic effects related to atomic state energy changes from the host material are a limiting factor. One example is a neutrino mass study based on the nuclear EC decay of to inside cryogenic -based sensors. To understand the material effects at the required level, we use density-functional theory to model the electronic structure of lithium atoms in different atomic environments of the polycrystalline absorber film. The calculations reveal that the 1s binding energies can vary by more than 2 eV due to insertion at different lattice sites, at grain boundaries, in disordered , and in the vicinity of various impurities. However, the total range of 1s shifts does not exceed 4 eV, even for extreme amorphous disorder. Furthermore, when investigating the effects on the 2s levels, we find broadening of more than 5 eV due to hybridization with the band structure. Material effects are shown to contribute significantly to peak broadening in -based sensors that are used to search for physics beyond the standard model in the EC decay of , but they do not explain the full extent of observed broadening. Understanding these in-medium effects will be required for current- and future-generation experiments that observe low-energy radiation from the EC decay of implanted isotopes to evaluate potential limitations on the measurement sensitivity.
Physics Subject Headings (PhySH)
Article Text
References (22)
- L. Gastaldo, K. Blaum, A. Doerr, Ch. E. Düllmann, K. Eberhardt, S. Eliseev, C. Enss, A. Faessler, A. Fleischmann, S. Kempf, et al., The Electron Capture Experiment ECHo, J. Low Temp. Phys. 176, 876 (2014).
- B. Alpert, M. Balata, D. Bennett, M. Biasotti, C. Boragno, C. Brofferio, V. Ceriale, D. Corsini, P. K. Day, M. De Gerone, et al., HOLMES: The electron capture decay of to measure the electron neutrino mass with sub-eV sensitivity, Eur. Phys. J. C 75, 112 (2015).
- S. Friedrich, G. B. Kim, C. Bray, R. Cantor, J. Dilling, S. Fretwell, J. A. Hall, A. Lennarz, V. Lordi, P. Machule, et al., Limits on the Existence of sub-MeV Sterile Neutrinos from the Decay of in Superconducting Quantum Sensors, Phys. Rev. Lett. 126, 021803 (2021).
- S. Fretwell, K. G. Leach, C. Bray, G. B. Kim, J. Dilling, A. Lennarz, X. Mougeot, F. Ponce, C. Ruiz, J. Stackhouse, and S. Friedrich, Direct Measurement of the L/K Capture Ratio in -Based Superconducting Tunnel Junctions, Phys. Rev. Lett. 125, 032701 (2020).
- M. Drescher, M. Hentschel, R. Kienberger, M. Uiberacker, V. Yakovlev, A. Scrinzi, Th. Westerwalbesloh, U. Kleineberg, U. Heinzmann, and F. Krausz, Time-resolved atomic inner-shell spectroscopy, Nature 419, 803 (2002).
- Y. Blumenfeld, T. Nilsson, and P. van Duppen, Facilities and methods for radioactive ion beam production, Phys. Scr. T152, 014023 (2013).
- R. Adhikari, M. Agostini, N. Anh Ky, T. Araki, M. Archidiacono, M. Bahr, J. Baur, J. Behrens, F. Bezrukov, P. S. Bhupal Dev, et al., A white paper on keV sterile neutrino dark matter, J. Cosmol. Astropart. Phys. 1, 025 (2017).
- W. Kohn and L. J. Sham, Self-consistent equations including exchange and correlation effects, Phys. Rev. 140, A1133 (1965).
- R. M. Martin, Electronic Structure: Basic Theory and Practical Methods (Cambridge University Press, New York, 2008).
- G. Kresse and J. Furthmüller, Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set, Phys. Rev. B 54, 11169 (1996).
- G. Kresse and J. Furthmüller, Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set, Comput. Mater. Sci. 6, 15 (1996).
- J. Hafner, Ab-initio simulations of materials using VASP: Density-functional theory and beyond, J. Comput. Chem. 29, 2044 (2008).
- J. P. Perdew, K. Burke, and M. Ernzerhof, Generalized Gradient Approximation Made Simple, Phys. Rev. Lett. 77, 3865 (1996).
- A. P. Sutton and R. W. Balluffi, Interfaces in Crystalline Materials (Oxford University Press, New York, 1995).
- T. Frolov, Q. Zhu, T. Oppelstrup, J. Marian, and R. E. Rudd, Structures and transitions in bcc tungsten grain boundaries and their role in the absorption of point defects, Acta Mater. 159, 123 (2018).
- J. P. Hirth and J. Lothe, Theory of Dislocations (Wiley, New York, 1982).
- A. S. Argon, Strengthening Mechanisms in Crystal Plasticity (Oxford University Press, Oxford, UK, 2008).
- D. Rodney and J. Bonneville, in Physical Metallurgy, 5th ed., edited by D. Laughlin, K. Hono (Elsevier, Amsterdam, 2014), Vol. II.
- V. Vitek, Theory of the core structures of dislocations in body-centered-cubic metals, Cryst. Latt. Defects 5, 1 (1974).
- V. V. Bulatov and W. Cai, Computer Simulations of Dislocations (Oxford University Press, New York, 2006).
- E. Clouet, L. Ventelon, and F. Willaime, Dislocation Core Energies and Core Fields from First Principles, Phys. Rev. Lett. 102, 055502 (2009).
- L. Boyer, D. A. Papaconstantopoulos, and B. M. Klein, Effect of self-consistency and exchange on the electronic structure of the transition metals, , , and , Phys. Rev. B 15, 3685 (1977).
