Thorium silicate compound as a solid-state target for production of isomeric thorium-229 nuclei by electron beam irradiation

Borisyuk, P. V.; Vasilyev, O. S.; Lebedinskiǐ, Yu. Yu.; Krasavin, А. V.; Tkalya, E. V.; Troyan, V. I.; Habibulina, R. F.; Chubunova, E. V.; Yakovlev, V. P.

doi:10.1063/1.4962661

Cited by 5 publications

(5 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Several alternative ways to excite the nucleus have been proposed in the literature. These include 229m Th excitation via surface plasmons [393], via Coulomb excitation [3,146], low-energy ion scattering spectroscopy [35] and electronbeam surface irradiation [36,374,385]. Also several theoretical proposals were put forward that make use of a storage ring for the investigation 229m Th: the isomeric decay in hydrogen-like 229 Th (Th 89+ ) was considered by Karpeshin et al in 1998 [162].…”

Section: A33 Nuclear Excitation By Electron Capturementioning

confidence: 99%

The $$^{229}$$Th isomer: prospects for a nuclear optical clock

Wense

2020

Eur. Phys. J. A

View full text Add to dashboard Cite

The proposal for the development of a nuclear optical clock has triggered a multitude of experimental and theoretical studies. In particular the prediction of an unprecedented systematic frequency uncertainty of about $$10^{-19}$$ 10 - 19 has rendered a nuclear clock an interesting tool for many applications, potentially even for a re-definition of the second. The focus of the corresponding research is a nuclear transition of the $$^{229}$$ 229 Th nucleus, which possesses a uniquely low nuclear excitation energy of only $$8.12\pm 0.11$$ 8.12 ± 0.11 eV ($$152.7\pm 2.1$$ 152.7 ± 2.1 nm). This energy is sufficiently low to allow for nuclear laser spectroscopy, an inherent requirement for a nuclear clock. Recently, some significant progress toward the development of a nuclear frequency standard has been made and by today there is no doubt that a nuclear clock will become reality, most likely not even in the too far future. Here we present a comprehensive review of the current status of nuclear clock development with the objective of providing a rather complete list of literature related to the topic, which could serve as a reference for future investigations.

show abstract

Section: A33 Nuclear Excitation By Electron Capturementioning

confidence: 99%

The $$^{229}$$Th isomer: prospects for a nuclear optical clock

Wense

2020

Eur. Phys. J. A

View full text Add to dashboard Cite

show abstract

“…( 1) spectral distribution of imaginary (ε j2 ) and Spectral distributions of the macroscopic dielectric function were theoretically evaluated for ThO 2 and SiO 2 crystalline materials by ab initio studies based on the density functional theory (DFT). The calculations have been made by using Vienna ab initio simulation package (VASP) [34,35,36] together with the projector augmented-wave (PAW) pseudopotential method [5,6,7,37,38,39]. Exchange and correlation effects have been taken into account within the Perdew-Burke-Ernzerhof (PBE) [40,41] generalizedgradient approximation (f (PBE) GGA) functional [8] or Heyd-Scuseria-Ernzerhofhof hybrid functional (HSE06) (HSE) [9,10,42].…”

Section: Ab Initio Calculationsmentioning

confidence: 99%

“…Currently, wide-band gap materials doped with thorium ions are subject of intensive studies [1,2,3,4,5] This is due to the fact that such materials could serve as the most promising for the study of a unique anomalously low-lying isomeric state of the 229 Th nucleus [6] with the energy of 7.8 ± 0.5 eV [7,8]. However, the measurement uncertainty of ∼ 0.5 eV requires a frequency tuning in the range of ∼ 250 THz that leads to significant impediment to use precision of laser spectroscopy techniques for direct detection of the desired transition.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Experimental studies of thorium ion implantation from pulse laser plasma into thin silicon oxide layers

et al. 2018

View full text Add to dashboard Cite

We report the results of experimental studies related to implantation of thorium ions into thin silicon dioxide by pulsed plasma fluxes expansion. Thorium ions were generated by laser ablation from a metal target, and the ionic component of the laser plasma was accelerated in an electric field created by the potential difference (5, 10 and 15 kV) between the ablated target and SiO 2 /Si (001) sample. Laser ablation system installed inside the vacuum chamber of the electron spectrometer was equipped with YAG:Nd3+ laser having the pulse energy of 100 mJ and time duration of 15 ns in the Q-switched regime. Depth profile of thorium atoms implanted into the 10 nm thick subsurface areas together with their chemical state as well as the band gap of the modified silicon oxide at different conditions of implantation processes were studied by means of X-ray photoelectron spectroscopy (XPS) and Reflected Electron Energy Loss Spectroscopy (REELS) methods. Analysis of chemical composition showed that the modified silicon oxide film contains complex thorium silicates. Depending on local concentration of thorium atoms, the experimentally established band gaps were located in the range of 6.0 -9.0 eV. Theoretical studies of optical properties of the SiO 2 and ThO 2 crystalline systems have been performed by ab initio calculations within hybrid functional. Optical properties of the SiO 2 /ThO 2 composite were interpreted on the basis of Bruggeman effective medium approximation. A quantitative assessment of the yield of isomeric nuclei in "hot" laser plasma at the early stages of expansion has been performed. The estimates made with experimental results demonstrated that the laser implantation of thorium ions into the SiO 2 matrix can be useful for further research of low-lying isomeric transitions in 229 Th isotope with energy of 7.8 ± 0.5 eV.

show abstract

“…Broadband dielectric crystals doped with thorium-229 nuclei are currently the subject of active research [1][2][3][4][5][6][7]. This is due to the fact that such systems are considered as the most promising for exploring studies of a unique anomalously lowlying isomeric state in the thorium-229 nuclei [8] with energy of 8.10 ± 0.17 eV [9] and 8.12 ± 0.11 [10] (previously, the energy value accepted by the scientific community for a long time was 7.8 ± 0.5 eV [11]), that is, the optical wavelength is located in the vacuum ultraviolet region of 153.0 ± 2.1 nm and, in principle, is available to current laser sources.…”

Section: Introductionmentioning

confidence: 99%

Autoelectronic emission and charge relaxation of thorium ions implanted into a thin-film silicon oxide matrix

Borisyuk¹,

Chubunova²,

Kolachevsky³

et al. 2021

Laser Phys. Lett.

View full text Add to dashboard Cite

An ensemble of thorium-229 ions embedded by pulsed laser implantation into a matrix of a broadband dielectric-silicon oxide is studied. The results of the experimental investigation of thorium ions’ lifetime as charged components of the Th+/SiO2/Si system formed immediately after laser implantation are presented. The modelled theoretical description takes into account the instantaneous charging of the surface via laser implantation followed by charge relaxation due to the effect of autoelectronic emission that leads to time dependent partial neutralization of the surface charge by tunneling electrons. It was found that the lifetime of Th+ ions on the SiO2 surface can exceed 10 s, which would be an attractive opportunity for studying the nuclear low-lying isomeric transition in the thorium-229 isotope.

show abstract

Thorium silicate compound as a solid-state target for production of isomeric thorium-229 nuclei by electron beam irradiation

Cited by 5 publications

References 17 publications

The $$^{229}$$Th isomer: prospects for a nuclear optical clock

The $$^{229}$$Th isomer: prospects for a nuclear optical clock

Experimental studies of thorium ion implantation from pulse laser plasma into thin silicon oxide layers

Autoelectronic emission and charge relaxation of thorium ions implanted into a thin-film silicon oxide matrix

Contact Info

Product

Resources

About