Phys. Rev. Lett. 80, 2085–2088 (1998)β+ Decay Partial Half-Life of 54Mn and Cosmic Ray ChronometryReceived 25 September 1997; published in the issue dated 9 March 1998 The weak β+ decay of the astrophysically significant radioisotope 54Mn has been observed. The energies of positrons from a chemically purified 54Mn source were measured using the APEX spectrometer at Argonne National Laboratory. We deduce a β+ decay branch of (1.20±0.26)×10-9, corresponding to a partial half-life of (7.1±1.5)×108yr. The implications of this value for cosmic-ray confinement times are discussed in light of recent satellite measurements of the cosmic-ray abundance of 54Mn. © 1998 The American Physical Society URL:
http://link.aps.org/doi/10.1103/PhysRevLett.80.2085
DOI:
10.1103/PhysRevLett.80.2085
PACS:
23.40.Hc, 26.40.+r, 27.40.+z, 98.38.-j
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