Energy Splitting of the Ground-State Doublet in the Nucleus {sup 229}Th

Journal Article · Fri Apr 06 04:00:00 EDT 2007 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.98.142501· OSTI ID:20951206

Beck, B R; Becker, J A; Beiersdorfer, P; Brown, G V; Moody, K J ^[1]; Wilhelmy, J B ^[2]; Porter, F S; Kilbourne, C A; Kelley, R L ^[3]

---

1. Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)
2. Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)
3. NASA Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States)

The energy splitting of the {sup 229}Th 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 {sup 233}U (105 {mu}Ci) 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 to 0.6 eV was made for the unobserved interband decay of the 29.19 keV state (29.19{yields}0 keV)

• OSTI ID: 20951206
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 14 Vol. 98; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALPHA DECAY
CALORIMETERS
ELECTRON BEAMS
ENERGY RESOLUTION
EV RANGE 01-10
EV RANGE 10-100
GAMMA RADIATION
GROUND STATES
KEV RANGE 10-100
SPECTROMETERS
THORIUM 229
URANIUM 233
X RADIATION