Results of a Direct Search Using Synchrotron Radiation for the Low-Energy (229)Th Nuclear Isomeric Transition.

  title={Results of a Direct Search Using Synchrotron Radiation for the Low-Energy (229)Th Nuclear Isomeric Transition.},
  author={J. Jeet and Christian Schneider and Scott T. Sullivan and Wade G. Rellergert and Saed Mirzadeh and Arlete Cassanho and Hans P. Jenssen and E V Tkalya and Eric R. Hudson},
  journal={Physical review letters},
  volume={114 25},
We report the results of a direct search for the (229)Th (I(π)=3/2(+)←5/2(+)) nuclear isomeric transition, performed by exposing (229)Th-doped LiSrAlF(6) crystals to tunable vacuum-ultraviolet synchrotron radiation and observing any resulting fluorescence. We also use existing nuclear physics data to establish a range of possible transition strengths for the isomeric transition. We find no evidence for the thorium nuclear transition between 7.3 eV and 8.8 eV with transition lifetime (1-2) s… 

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  • Phys. Eng. Sci. Med. 25, 102
  • 2002


  • Phys. A 703, 45
  • 2002


  • Rev. C 79, 034302
  • 2009

Phys. Rev. Lett

  • Phys. Rev. Lett
  • 1999


  • Rev. Lett. 82, 505
  • 1999

This work is supported by the DARPA QuASAR program and the ARO under W911NF-11-1- 0369:P00004, NIST PMG, and DOE Office of Nuclear Physics, Isotope Program

  • This work is supported by the DARPA QuASAR program and the ARO under W911NF-11-1- 0369:P00004, NIST PMG, and DOE Office of Nuclear Physics, Isotope Program

Phys. Rev. Lett

  • Phys. Rev. Lett
  • 1995