Internal conversion of the low-energy Th<mml:mprescripts/><mml:none/>229m isomer in the thorium anion

2020/04/29 by E. V. Tkalya, R. Si · 8 citations
Physics and Astronomy · #Advanced Chemical Physics Studies #Amplitude #Atomic and Molecular Physics #Atomic physics #Electron #Energy (signal processing) #Excited state #Ground state #Ion #Nuclear physics #Nuclear physics research studies #Physics #Quantum mechanics #Wave function #nucl-th

paper · pdf · doi:10.1103/physrevc.101.054602

published in Physical Review C 101(5) (American Institute of Physics) · 7 pages, 4 figures

arxiv created 2020/04/29 · openalex publication_date 2020/05/06 · openalex created_date 2020/05/13 · arxiv updated 2020/05/20 · openalex updated_date 2026/08/05

Abstract

A process of the decay of the anomalously low-lying nuclear isomer ^229mTh(3/2⁺,8.28\ifmmode±\else\textpm\fi0.17 eV) in the thorium anion (Th^\ensuremath-) via the internal conversion (IC) channel is studied. We show that the half-life of the nuclear isomer in the 6d_3/2³7s_1/2² ground state and in the 6d_3/2²7s_1/2²7p_1/2¹ excited state of Th^\ensuremath- is \ensuremath≈1.5 and \ensuremath≈1.1 times bigger than in the 6d_3/2²7s_1/2² ground state of the Th atom. The IC probabilities in the anion decreases despite the decay via the additional 6d_3/2 or 7p_1/2 electrons. This counterintuitive result is a consequence (a) of a decrease in the amplitudes of the 6d_3/2 and 7s_1/2 wave functions near the nucleus due to an increase in their diffuseness of upon the addition of extra electron and (b) of mutual compensation in the IC probability due to a kinematic factor, which depends on the energy of the conversion electron in the continuum as E_c^\ensuremath-1/2, and the E_c^1/4 growth of the amplitudes of the electron wave functions.

Citations

• Energy Splitting of the Ground-State Doublet in the NucleusTh<mml:mprescripts/><mml:none/>229
• Nuclear laser spectroscopy of the 3.5 eV transition in Th-229
• Nuclear structure of 229Th
• Features of the low-energy level scheme of 229Th as observed in the α-decay of 233U
• Single-Ion Nuclear Clock for Metrology at the 19th Decimal Place
• Observation of the Deexcitation of theTh<mml:mprescripts/><mml:none/>229mNuclear Isomer
• Energy separation of the doublet of intrinsic states at the ground state ofTh<mml:mprescripts/>229
• Processes of the nuclear isomer 229mTh(3/2+, 3.5 ± 1.0 eV) resonant excitation by optical photons
• Radiative lifetime and energy of the low-energy isomeric level inTh<mml:mprescripts/><mml:none/>229
• Direct detection of the 229Th nuclear clock transition
• An excited state ofTh<mml:mprescripts/>229at 3.5 eV
• Lifetime measurement of the ²²⁹Th nuclear isomer
• Reduced transition probabilities for the gamma decay of the 7.8 eV isomer in ²²⁹Th
• Laser spectroscopic characterization of the nuclear clock isomer ^229mTh
• X-ray pumping of the Th-229 nuclear clock isomer
• Energy of the ²²⁹Th nuclear clock transition
• Candidate for Laser Cooling of a Negative Ion: High-Resolution Photoelectron Imaging of Th−