Oxidation State of 229Th Recoils Implanted into MgF2 Crystals
Science Journal of Chemistry
Volume 6, Issue 4, August 2018, Pages: 66-76
Received: Aug. 31, 2018; Accepted: Sep. 25, 2018; Published: Oct. 31, 2018
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Authors
Beau J. Barker, Idaho National Laboratory, Idaho Falls, USA
Edmund R. Meyer, Los Alamos National Laboratory, Los Alamos, USA
Michael H. Schacht, Los Alamos National Laboratory, Los Alamos, USA
Lee A. Collins, Los Alamos National Laboratory, Los Alamos, USA
Marianne P. Wilkerson, Los Alamos National Laboratory, Los Alamos, USA
Jason K. Ellis, Los Alamos National Laboratory, Los Alamos, USA
Richard L. Martin, Los Alamos National Laboratory, Los Alamos, USA
Xinxin Zhao, Los Alamos National Laboratory, Los Alamos, USA
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Abstract
A solid-state nuclear clock based on the low-lying isomeric state in 229Th has attracted growing interest. One potential problem for the solid-state nuclear clock approach is the suitability of the doped environment for photon emission of the nuclear isomeric state. Specifically, Thn+ n < 4 ions could open non-radiative decay routes for deexcitation, hindering the photon emission. Here we have used time-resolved photoluminescence (TRPL) and density functional theory (DFT) calculations to characterize MgF2 crystals that have been implanted with 229Th recoils via a-decay from a 233U source with the goal of determining the charge state of the implanted thorium atoms. The DFT calculations predicted Th4+ to be the lowest energy oxidation state with Th3+ the next lowest in the MgF2 crystal environment. The DFT calculations also show Th4+:MgF2 system has a band gap large enough so that the internal electron conversion decay channel is suppressed. Experimentally, we found no evidence for thorium in oxidations state other than +4 using TRPL spectroscopy that has a detection limit for Thn+ n < 4 ions several orders of magnitude smaller than the number of implanted 229Th recoils. This work shows that the solid-state approach is a viable option for a nuclear clock.
Keywords
229Th Isomeric State, Nuclear Clock, Optical Spectroscopy, Density Functional Theory, Thorium Doped MgF2 Crystal
To cite this article
Beau J. Barker, Edmund R. Meyer, Michael H. Schacht, Lee A. Collins, Marianne P. Wilkerson, Jason K. Ellis, Richard L. Martin, Xinxin Zhao, Oxidation State of 229Th Recoils Implanted into MgF2 Crystals, Science Journal of Chemistry. Vol. 6, No. 4, 2018, pp. 66-76. doi: 10.11648/j.sjc.20180604.15
Copyright
Copyright © 2018 Authors retain the copyright of this article.
This article is an open access article distributed under the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
References
[1]
L. A. Kroger and C. W. Reich, Features of the low-energy level scheme of 229Th as observed in the a-decay of 233U, Nucl. Phys. A259, 29 (1976).
[2]
R. G. Helmer and C. W. Reich, An excited state of 229Th at 3.5 eV, Phys. Rev. C 49, 1845 (1994).
[3]
C. J. Campbell, A. G. Radnaev, A. Kuzmich, V. A. Dzuba, V. V. Flambaum, and A. Derevianko, Single-ion nuclear clock for metrology at the 19th decimal place, Phys. Rev. Lett. 108, 120802 (2012).
[4]
G. A. Kazakov, A. N. Litvinov, V. I. Romanenko, L. P. Yatsenko, A. V. Romanenko, M. Schreitl, G. Winkler, and T. Schumm, Performance of a 229Thorium solid-state nuclear clock, New J. Phys. 14, 083019 (2012).
[5]
T. L. Nicholson, S. L. Campbell, R. B. Hutson, G. E. Marti, B. J. Bloom, R. L. McNally, W. Zhang, M. D. Barrett, M. S. Safronova, G. F. Strouse, W. L. Tew, and J. Ye, Systematic evaluation of an atomic clock at 2 x 10-18 total uncertainty, Nat. Commun. 6, 6896 (2015).
[6]
J. C. Berengut, V. A. Dzuba, V. V. Flambaum, and S. G. Porsev, Proposed experimental method to determine a sensitivity of splitting between ground and 7.6 eV isomeric states in 229Th, Phys. Rev. Lett. 102, 210801 (2009).
[7]
E. Litvinova, H. Feldmeier, J. Dobaczewski, and V. Flambaum, Nuclear structure of lowest 229Th states and time-dependent fundamental constants, Phys. Rev. C 79, 034302 (2009).
[8]
E. V. Tkalya, Proposal for a nuclear gamma-ray laser of optical range, Phys. Rev. Lett. 106, 162501 (2011).
[9]
E. Peik and M. Okhapkin, Nuclear clocks based on resonant excitation of γ-transitions, C. R. Phys. 16, 516 (2015).
[10]
B. R. Beck, J. A. Becker, P. Beiersdorfer, G. V. Brown, K. J. Moody, J. B. Wilhelmy, F. S. Porter, C. A. Kilbourne, and R. L. Kelley, Energy splitting of the ground-state doublet in the nucleus 229Th, Phys. Rev. Lett. 98, 142501 (2007).
[11]
B. R. Beck, J. A. Becker, P. Beiersdorfer, G. V. Brown, K. J. Moody, C. Y. Wu, J. B. Wilhelmy, F. S. Porter, C. A. Kilbourne, and R. L. Kelley, Improved value for the energy splitting of the ground-state doublet in the nucleus 229Th in 12th International Conference on Nuclear Reaction Mechanisms, edited by F. Cerutti, and A. Ferrari (CERN, Genva, 2009), p. 225.
[12]
L. von der Wense, B. Seiferle, M. Laatiaoui, J. B. Neumayr, H.-J. Maier, H.-F. Wirth, C. Mokry, J. Runke, K. Eberhardt, C. E. Düllmann, N. G. Trautmann, and P. G. Thirolf, Direct detection of the 229Th nuclear clock transition, Nature 533, 47 (2016).
[13]
W. G. Rellergert, D. DeMille, R. R. Greco, M. P. Hehlen, J. R. Torgerson, and E. R. Hudson, Constraining the evolution of the fundamental constants with a solid-state optical frequency reference based on the 229Th nucleus, Phys. Rev. Lett. 104, 200802 (2010).
[14]
W. G. Rellergert, S. T. Sullivan, D. DeMille, R. R. Greco, M. P. Hehlen, R. A. Jackson, J. R. Torgerson, and E. R. Hudson, Progress towards fabrication of 229Th-doped high energy band-gap crystals for use as a solid-state optical frequency reference, IOP Conf. Ser.: Mater. Sci. Eng. 15, 012005 (2010).
[15]
M. P. Hehlen, R. R. Greco, W. G. Rellergert, S. T. Sullivan, D. DeMille, R. A. Jackson, E. R. Hudson, and J. R. Torgerson, Optical spectroscopy of an atomic nucleus: Progress toward direct observation of the 229Th isomer transition, J. Lumin. 133, 91 (2013).
[16]
X. Zhao, Y. N. Martinez de Escobar, R. Rundberg, E. M. Bond, A. Moody, and D. J. Vieira, Observation of the deexcitation of the 229mTh nuclear isomer, Phys. Rev. Lett. 109, 160801 (2012).
[17]
E. Peik and K. Zimmermann, Comment on “observation of the deexcitation of the 229mTh nuclear isomer”, Phys. Rev. Lett. 111, 018901 (2013).
[18]
A. Yamaguchi, M. Kolbe, H. Kaser, T. Reichel, A. Gottwald, and E. Peik, Experimental search for the low-energy nuclear transition in 229Th with undulator radiation, New J. Phys. 17, 053053 (2015).
[19]
J. Jeet, C. Schneider, S. T. Sullivan, W. G. Rellergert, S. Mirzadeh, A. Cassanho, H. P. Jenssen, E. V. Tkalya, and E. R. Hudson, Results of a direct search using synchrotron radiation for the low-energy 229Th nuclear isomeric transition, Phys. Rev. Lett. 114, 253001 (2015).
[20]
E. V. Tkalya, C. Schneider, J. Jeet, and E. R. Hudson, Radiative lifetime and energy of the low-energy isomeric level in 229Th, Phys. Rev. C 92, 054324 (2015).
[21]
J. R. Walensky, R. L. Martin, J. W. Ziller, and W. J. Evans, Importance of energy level matching for bonding in Th3+-Am3+ actinide metallocene amidinates, (C5Me5) 2 [iPrNC (Me) NiPr] An, Inorg. Chem. 49, 10007 (2010).
[22]
P. V. Borisyuk, O. S. Vasilyev, A. V. Krasavin, Y. Y. Lebedinskii, V. I. Troyan, and E. V. Tkalya, Band structure and decay channels of thorium-229 low-lying isomeric state for ensemble of thorium atoms adsorbed on calcium fluoride, Phys. Status Solidi C 12, 1333 (2015).
[23]
L. von der Wense, P. G. Thirolf, D. Kalb, and M. Laatiaoui, Towards a direct transition energy measurement of the lowest nuclear excitation in 229Th, JINST 8, P03005 (2013).
[24]
L. von der Wense, B. Seiferle, M. Laatiaoui, and P. G. Thirolf, Determination of the extraction efficiency for 233U source α-recoil ions from the MLL buffer-gas stopping cell, Eur. Phys. J. A 51, 29 (2015).
[25]
G. Kresse and J. Hafner, Ab initio molecular dynamics for liquid metals, Phys. Rev. B 47, 558 (1993).
[26]
G. Kresse and J. Hafner, Ab initio molecular-dynamics simulation of the liquid-metal–amorphous-semiconductor transition in germanium, Phys. Rev. B 49, 14251 (1994).
[27]
G. Kresse and J. Furthmüller, Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set, Comput. Mat. Sci. 6, 15 (1996).
[28]
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).
[29]
J. P. Perdew and A. Zunger, Self-interaction correction to density-functional approximations for many-electron systems, Phys. Rev. B 23, 5048 (1981).
[30]
P. Dessovic, P. Mohn, R. A. Jackson, G. Winkler, M. Schreitl, G. Kazakov, and T. Schumm, 229Thorium-doped calcium fluoride for nuclear laser spectroscopy, J. Phys.: Condens. Matter 26, 105402 (2014).
[31]
L. Hedin, New method for calculating the one-particle green's function with application to the electron-gas problem, Phys. Rev. 139, A796 (1965).
[32]
M. Shishkin and G. Kresse, Implementation and performance of the frequency-dependent GW method within the PAW framework, Phys. Rev. B 74, 035101 (2006).
[33]
W. Chen and A. Pasquarello, Band-edge levels in semiconductors and insulators: Hybrid density functional theory versus many-body perturbation theory, Phys. Rev. B 86, 035134 (2012).
[34]
A. A. Mostofi, J. R. Yates, G. Pizzi, Y.-S. Lee, I. Souza, D. Vanderbilt, and N. Marzari, An updated version of wannier90: A tool for obtaining maximally-localised Wannier functions, Comput. Phys. Commun. 185, 2309 (2014).
[35]
J. Thomas, G. Stephan, J. C. Lemonnier, M. Nisar, and S. Robin, Optical anisotropy of MgF2 in its UV absorption region, Phys. Status Solidi B 56, 163 (1973).
[36]
M. Scrocco, Electron-energy-loss and x-ray photoelectron spectra of MgF2, Phys. Rev. B 33, 7228 (1986).
[37]
Z. Varga, A. Nicholl, and K. Mayer, Determination of the 229Th half-life, Phys. Rev. C 89, 064310 (2014).
[38]
M. P. Wilkerson and J. M. Berg, Excitation spectra of near-infrared photoluminescence from Np (VI) in Cs2U (Np) O2Cl4, Radiochim. Acta 97, 223 (2009).
[39]
B. J. Barker, J. M. Berg, S. A. Kozimor, N. R. Wozniak, and M. P. Wilkerson, Visible and near-infrared excitation spectra from the neptunyl ion doped into a uranyl tetrachloride lattice, J. Mol. Struct. 1108, 594 (2016).
[40]
S. Y. E. Chu, L. P. Ekstrom, and R. B. Firestone, in WWW Table of Radioactive Isotopes database version 1999-02-28 URL http://nucleardata.nuclear.lu.se/nucleardata/toi/2016).
[41]
J. G. Solé, L. E. Bausá, and D. Jaque, Applications: Rare Earth and Transition Metal Ions, and Color Centers in An Introduction to the Optical Spectroscopy of Inorganic Solids (John Wiley & Sons, Ltd, 2005), p. 207.
[42]
J.-C. G. Bunzli and S. V. Eliseeva, Basics of Lanthanide Photophysics in Lanthanide Luminescence: Photophysical, Analytical and Biological Aspects, edited by P. Hanninen, and H. Harma (Springer-Verlag, Berlin, 2011), p. 18.
[43]
L. Andrews, K. S. Thanthiriwatte, X. Wang, and D. A. Dixon, Thorium Fluorides ThF, ThF2, ThF3, ThF4, ThF3 (F2), and ThF5– Characterized by Infrared Spectra in Solid Argon and Electronic Structure and Vibrational Frequency Calculations, Inorg. Chem. 52, 8228 (2013).
[44]
S. P. S. Porto, P. A. Fleury, and T. C. Damen, Raman Spectra of TiO2, MgF2, ZnF2, FeF2 and MnF2, Phys. Rev. 154, 522 (1967).
[45]
A. S. Barker, Transverse and Longitudinal Optic Mode Study in MgF2 and ZnF2, Phys. Rev. 136, A1290 (1964).
[46]
G. D. Boyd, R. J. Collins, S. P. S. Porto, A. Yariv, and W. A. Hargreaves, Excitation, Relaxation, and Continuous Maser Action in the 2.613-Micron Transition of CaF2:U3+, Phys. Rev. Lett. 8, 269 (1962).
[47]
G. J. Quarles, Rare-earth Ions - Miscellaneous: Ce3+, U3+, divalent, etc in Handbook of Laser Technology, edited by C. E. Webb, and J. D. C. Jones (Institute of Physics Publishing, Bristol, 2003), p. 418.
[48]
D. F. Shriver and P. W. Atkins, Inorganic Chemistry 3rd. Edition (W. H. Freeman and Co., New York, 1999), p. 453.
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