Towards a direct transition energy measurement of the lowest nuclear excitation in 229Th

@article{Wense2013TowardsAD,
  title={Towards a direct transition energy measurement of the lowest nuclear excitation in 229Th},
  author={L v d Wense and P G Thirolf and D Kalb and M Laatiaoui},
  journal={Journal of Instrumentation},
  year={2013},
  volume={8},
  pages={P03005 - P03005}
}
The isomeric first excited state of the isotope 229Th exhibits the lowest nuclear excitation energy in the whole landscape of known atomic nuclei. For a long time this energy was reported in the literature as 3.5(5) eV, however, a new experiment corrected this energy to 7.6(5) eV, corresponding to a UV transition wavelength of 163(11) nm. The expected isomeric lifetime is τ = 3-5 hours, leading to an extremely sharp relative linewidth of ΔE/E ≈ 10−20, 5-6 orders of magnitude smaller than… 

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  • Physics
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  • 2017
Recently, the first direct detection of the long-searched low-lying isomeric first excited state of 229Th could be realized via its internal conversion decay branch, which confirms the isomer's

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The direct detection of this nuclear state of 229mTh is reported, which is further confirmation of the existence of the isomer and lays the foundation for precise studies of its decay parameters.

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References

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TLDR
The first direct observation of the deexcitation of the lowest-lying isomeric state in (229)Th is reported, which lays the groundwork for optical and laser spectroscopy of (229m)Th nuclear isomer and the development of a new type of clock based on this nuclear transition.

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TLDR
It is argued that the 229Th optical nuclear transition may be driven inside a host crystal with a high transition Q to allow for the construction of a solid-state optical frequency reference that surpasses the short-term stability of current optical clocks, as well as improved limits on the variability of fundamental constants.

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TLDR
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We have made an improved estimate of the {sup 229m}Th isomer energy. The new value, 7.8(5) eV, includes an estimate of possible spectral contamination effects due to the out-of-band E2 transition

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  • Physics
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TLDR
It has been known for many years that the first excited state of [sup 229]Th lies close to the ground state, and in an attempt to improve the value for this level energy, a number of [gamma] rays from [sup 223]U whose positions in the [sup229]Th level scheme can be used to establish it.

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The energy splitting of the 229Th ground-state doublet is measured to be 7.6+/-0.5 eV, significantly greater than earlier measurements. Gamma rays produced following the alpha decay of 233U (105

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The 7.8 eV nuclear isomer transition in 229thorium has been suggested as a clock transition in a new type of optical frequency standard. Here we discuss the construction of a ‘solid-state nuclear

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In-source resonance ionization spectroscopy was used to identify an efficient and selective three-step excitation/ionization scheme of thorium, suitable for titanium:sapphire (Ti:sa) lasers. The

Coulomb energy contribution to the excitation energy in 229Th and enhanced effect of α variation

We estimated the polarization contribution of Coulomb energy to the spacing between the ground and first excited state of the 229Th nucleus as a function of the deformation parameter δ. We show that