Excitation of the {sup 229m}Th nuclear isomer via resonance conversion in ionized atoms

Journal Article · Tue Sep 15 04:00:00 EDT 2015 · Physics of Atomic Nuclei

DOI:https://doi.org/10.1134/S1063778815060125· OSTI ID:22472165

Trzhaskovskaya, M. B. ^[1]

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1. National Research Center Kurchatov Institute, Petersburg Nuclear Physics Institute (Russian Federation)

Pressing problems concerning the optical pumping of the 7.6-eV {sup 229m}Th nuclear isomer, which is a candidate for a new nuclear optical reference point for frequencies, are examined. Physics behind the mechanism of the two-photon optical pumping of the isomer is considered. It is shown that, irrespective of the pumping scheme, a dominant contribution comes, in accord with what was proven earlier for the 3.5-eV isomer, from the resonance 8s–7s transition. Details of an optimum experimental scheme are discussed. It is shown that, after isomer excitation, the atom involved remains with a high probability in an excited state at an energy of about 0.5 eV rather than in the ground state, the required energy of the two photons being equal to the energy of the nuclear level plus the energy of the lowest 7s state of the atom. The estimated pumping time is about 1.5 s in the case where the field strength of each laser is 1 V/cm.

• OSTI ID: 22472165
• Journal Information: Physics of Atomic Nuclei, Journal Name: Physics of Atomic Nuclei Journal Issue: 6 Vol. 78; ISSN 1063-7788; ISSN PANUEO
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
74 ATOMIC AND MOLECULAR PHYSICS
ATOMS
CONVERSION
EV RANGE
EXCITATION
EXCITED STATES
GROUND STATES
IONIZATION
ISOMERIC NUCLEI
LASER RADIATION
OPTICAL PUMPING
PHOTONS
PROBABILITY
RESONANCE