Laser spectroscopic characterization of the nuclear-clock isomer 229mTh

@article{Thielking2018LaserSC,
  title={Laser spectroscopic characterization of the nuclear-clock isomer 229mTh},
  author={Johannes Thielking and Maxim V. Okhapkin and P. Głowacki and David M. Meier and Lars von der Wense and Benedict Seiferle and Christoph Emanuel D{\"u}llmann and Peter G. Thirolf and Ekkehard Peik},
  journal={Nature},
  year={2018},
  volume={556},
  pages={321-325}
}
The isotope 229Th is the only nucleus known to possess an excited state 229mTh in the energy range of a few electronvolts—a transition energy typical for electrons in the valence shell of atoms, but about four orders of magnitude lower than typical nuclear excitation energies. Of the many applications that have been proposed for this nuclear system, which is accessible by optical methods, the most promising is a highly precise nuclear clock that outperforms existing atomic timekeepers. Here we… 
X-ray pumping of the 229Th nuclear clock isomer
TLDR
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.
The thorium-229 low-energy isomer and the nuclear clock
The 229Th nucleus has an isomeric state at an energy of about 8 eV above the ground state, several orders of magnitude lower than typical nuclear excitation energies. This has inspired the
Hyperfine interaction with the Th229 nucleus and its low-lying isomeric state
The thorium nucleus with mass number $A=229$ has attracted much interest because its extremely low lying first excited isomeric state at about $8$eV opens the possibility for the development of a
Energy of the 229Th nuclear clock transition
TLDR
The method combines nuclear and atomic physics measurements to advance precision metrology, and the findings are expected to facilitate the application of high-resolution laser spectroscopy on nuclei and to enable the development of a nuclear optical clock of unprecedented accuracy.
The concept of laser-based conversion electron Mössbauer spectroscopy for a precise energy determination of 229mTh
Abstract229Th is the only nucleus currently under investigation for the development of a nuclear optical clock (NOC) of ultra-high accuracy. The insufficient knowledge of the first nuclear excitation
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
Towards a precise determination of the excitation energy of the Thorium nuclear isomer using a magnetic bottle spectrometer
DFT calculation of 229thorium-doped magnesium fluoride for nuclear laser spectroscopy
TLDR
Using the Vienna Ab-initio Simulation Package (VASP), density functional theory (DFT) calculations of the electronic and optical properties of Th:MgF2 determine whether Thorium will be accepted as a dopant and identify the charge compensation mechanism and geometry, and indicate, that the band gap of Th-doped M gF2 will be significantly reduced compared to undoped Mgf2, below the expected229Th isomer energy.
Recent progress in laser spectroscopy of the actinides
Nuclear isomer excitation in Th229 atoms by superintense laser fields
Excitation of the isomeric nuclear state 229m Th in the process of thorium atom irradiation by two-color femtosecond pulse of Ti: Sa laser at the fundamental wavelength and second harmonic is
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References

SHOWING 1-10 OF 63 REFERENCES
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
Lifetime Measurement of the ^{229}Th Nuclear Isomer.
TLDR
The measurement of the internal-conversion decay half-life of neutral ^{229m}Th has been measured, which is in the range of theoretical predictions and gives further support for an internal conversion coefficient of ≈10^{9}, thus constraining the strength of a radiative branch in the presence of internal conversion.
Direct detection of the 229Th nuclear clock transition
TLDR
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.
Wigner crystals of 229Th for optical excitation of the nuclear isomer.
TLDR
A new value of the spectroscopic nuclear electric quadrupole moment Q=3.11(16) eb is deduced and is a step towards optical excitation of the low-lying isomer level in the 229Th nucleus.
Splitting sensitivity of the ground and 7.6 eV isomeric states of {sup 229}Th
The lowest-known excited state in nuclei is the 7.6 eV isomer of {sup 229}Th. This energy is within the range of laser-based investigations that could allow accurate measurements of possible temporal
Reduced Transition Probabilities for the Gamma Decay of the 7.8 eV Isomer in ^{229}Th.
TLDR
The reduced magnetic dipole and electric quadrupole transition probabilities for the radiative decay of the ^{229}Th 7.8  eV isomer to the ground state are predicted within a detailed nuclear-structure model approach and support new directions in the experimental search of the^{229]Th transition frequency for the development of a future nuclear frequency standard.
Experimental search for the low-energy nuclear transition in 229Th with undulator radiation
To search for the lowest energy nuclear isomeric transition in 229Th in solid samples, a novel adsorption technique which prepares 229Th atoms on a surface of CaF2 is developed. Adsorbed 229Th is
Constraining the evolution of the fundamental constants with a solid-state optical frequency reference based on the 229Th nucleus.
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.
Magnetic dipole and electric quadrupole moments of the 229Th nucleus
We calculate the A and B hyperfine constants for the low-lying states of 229Th3+ using a high-precision relativistic all-order approach. By combining these calculations with measurements of the 6d
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