Resonance ionization spectroscopy of thorium isotopes–towards a laser spectroscopic identification of the low-lying 7.6 eV isomer of 229Th

  title={Resonance ionization spectroscopy of thorium isotopes–towards a laser spectroscopic identification of the low-lying 7.6 eV isomer of 229Th},
  author={Sebastian Raeder and Volker Sonnenschein and Tina Gottwald and I. D. Moore and M. Reponen and Sebastian Rothe and Norbert Trautmann and Kerstin S. Wendt},
  journal={Journal of Physics B: Atomic, Molecular and Optical Physics},
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 measurements were carried out in the preparation of laser spectroscopic investigations for an identification of the low-lying 229mTh isomer predicted at 7.6 ± 0.5 eV above the nuclear ground state. Using a sample of 232Th, a multitude of optical transitions leading to over 20 previously unknown… 
The search for the existence of 229mTh at IGISOL
An overview of preparatory work aiming at the identification of the low-lying 7.6 eV isomer in 229Th through a measurement of its hyperfine structure is presented. A 233U recoil gas cell has been
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
Preparing an Isotopically Pure 229Th Ion Beam for Studies of 229mTh.
The presented method allowed for a first direct identification of the decay of the thorium isomer, laying the foundations to study its decay properties as prerequisite for an optical control of this nuclear transition.
Recent developments in resonance ionization mass spectrometry for ultra-trace analysis of actinide elements
Abstract Resonance ionization mass spectrometry is an efficient tool to detect minute amounts of long-lived radio-isotopes in environmental samples. Applying resonant excitation and ionization with
Trapping and sympathetic cooling of single thorium ions for spectroscopy
Precision optical spectroscopy of exotic ions reveals accurate information about nuclear properties such as charge radii and magnetic and quadrupole moments. Thorium ions exhibit unique nuclear
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
Resonance laser ionization of atoms for nuclear physics
The applications of the laser resonance ionization method in nuclear research are reviewed. Investigation of radioactive isotopes using resonance ionization techniques provides a valuable combination
Creation of inverse population in the 229Th ground-state doublet by means of a narrowband laser
A new method for obtaining inverse population between quadrupole sublevels of the ground state 5/2+(0.0) and the isomeric state 3/2+(7.6 eV) of the 229Th nucleus in a dielectric crystal with a large


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
Investigation of the low-lying isomer in 229Th by collinear laser spectroscopy
A new ion beam of 229Th is available at the Jyväsklyä IGISOL facility, produced from the α decay of 233U. A small branching ratio (≈ 2%) is believed to populate the inferred low-lying (5.5 eV)
Nuclear radii of thorium isotopes from laser spectroscopy of stored ions
Isotope shifts and hyperfine splittings in optical transitions for atomic ions of the thorium isotopes227Th to230Th and232Th have been measured by laser spectroscopy on stored ions. From the isotope
Energy splitting of the ground-state doublet in the nucleus 229Th.
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
ISOLDE RILIS: New beams, new facilities
Half-life estimation of the first excited state of Th-229 by using alpha-particle spectrometry
To search for a direct-decay signal from the isomer 229 Th m , α-particle spectra of 229 Th m,g produced from 93 mg of 233 U have been measured by using a rapid and high-resolution α-particle
Matrix element of the anomalously low-energy (3.5±0.5 eV) transition in 229Th and the isomer lifetime
The matrix element of the anomalously low-energy (3.5±0.5 eV) nuclear M1 transition between the first excited state and the ground state of the 229Th nucleus is determined with allowance for the