# Energy splitting of the ground-state doublet in the nucleus 229Th.

@article{Beck2007EnergySO,
title={Energy splitting of the ground-state doublet in the nucleus 229Th.},
author={B. R. Beck and John A. Becker and Peter Beiersdorfer and G V Brown and Kenton J. Moody and J. Wilhelmy and Frederick S. Porter and Caroline A. Kilbourne and Richard Lloyd Kelley},
journal={Physical review letters},
year={2007},
volume={98 14},
pages={
142501
}
}
• Published 6 April 2007
• Physics
• Physical review letters
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 muCi) were counted in the NASA/electron beam ion trap x-ray microcalorimeter spectrometer with an experimental energy resolution of 26 eV (FWHM). A difference technique was applied to the gamma-ray decay of the 71.82 keV level that populates both members of the doublet. A positive correction amounting…

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## References

SHOWING 1-10 OF 33 REFERENCES
Nuclear laser spectroscopy of the 3.5 eV transition in Th-229
• Physics
• 2003
We propose high-resolution laser spectroscopy of the 3.5 eV nuclear transition in Th-229 in isolated atoms. Laser excitation of the nucleus can be detected efficiently in a double-resonance method by
Observation of Electromagnetic Radiation from Deexcitation of the 229 Th Isomer
• Physics
• 1997
Experimental measurements of ultraviolet and visible emission from two samples containing {sup 233}U suggest the deexcitation of a reported 3.5eV isomeric level in {sup 229}Th. The unique phenomenon
Nuclear transitions induced by synchrotron x-rays.
We discuss two rare but interesting processes by which synchrotron x-rays with energies up to about 100 keV may be used to induce nuclear transitions. In the NEET (Nuclear Excitation by Electronic
Nuclear quantum optics with x-ray laser pulses.
• Physics
Physical review letters
• 2006
It is shown that present and upcoming high-frequency laser facilities, especially together with a moderate acceleration of the target nuclei to match photon and transition frequency, do allow for resonant laser-nucleus interaction.
Nuclear structure of 229 Th from γ-ray spectroscopy study of 233 U α-particle decay
• Materials Science
• 2003
The level structure of ${}^{229}\mathrm{Th},$ produced by \ensuremath{\alpha}-particle decay of ${}^{233}\mathrm{U},$ was studied with \ensuremath{\gamma}-ray spectroscopy measurements. The sources