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

  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},
  volume={98 14},
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… 

Figures and Tables from this paper

Prospects for measuring the 229Th isomer energy using a metallic magnetic microcalorimeter☆
  • G. Kazakov, V. Schauer, T. Schumm
  • Physics
    Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment
  • 2014
The 229Th Isomer Line as a Reference for a High-Precision Frequency Standard
The use of the nuclide 229Th as a new nuclear-optical frequency standard is studied theoretically. The mechanism for two-photon optical pumping of the 7.6 eV isomer through the optical shell in
Energy of the ^{229}Th Nuclear Clock Isomer Determined by Absolute γ-ray Energy Difference.
The low-lying isomeric state of ^{229}Th provides unique opportunities for high-resolution laser spectroscopy of the atomic nucleus and is determined by taking the absolute energy difference between the excitation energy required to populate the 29.2-keV state and the energy emitted in its decay to the isomersic excited state.
Determination of the ground-state hyperfine structure in neutral 229Th
The ground-state hyperfine structure of neutral 229Th has been measured for the first time using high-resolution resonance ionization spectroscopy. The measurements were performed as a preparatory
Proposed experimental method to determine alpha sensitivity of splitting between ground and 7.6 eV isomeric states in 229Th.
Measurements of the differences of atomic transition frequencies between thorium atoms (or ions) with the nucleus in the ground state and in the first excited (isomeric) state are proposed to enable extraction of the change in nuclear charge radius and electric-quadrupole moment between the isomers, and hence the alpha dependence of the isomeric transition frequency with reasonable accuracy.
Toward an energy measurement of the internal conversion electron in the deexcitation of the Th229 isomer
The first excited isomeric state of Th-229 has an exceptionally low energy of only a few eV and could form the gateway to high-precision laser spectroscopy of nuclei. The excitation energy of the
X-ray pumping of the 229Th nuclear clock isomer
Active optical pumping is presented using narrow-band 29-kiloelectronvolt synchrotron radiation to resonantly excite the second excited state of 229Th, which then decays predominantly into the isomer, enabling accurate determination of the 229mTh isomer’s energy, half-life and excitation linewidth.
Towards a direct transition energy measurement of the lowest nuclear excitation in 229Th
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
Feasibility study of internal conversion electron spectroscopy of 229mTh
Abstract.With an expected energy of 7.8(5) eV, the isomeric first excited state in 229Th exhibits the lowest excitation energy of all known nuclei. Until today, a value for the excitation energy has


Nuclear laser spectroscopy of the 3.5 eV transition in Th-229
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
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.
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 Data Sheets for A = 233☆☆☆
Nuclear structure of 229 Th from γ-ray spectroscopy study of 233 U α-particle decay
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