POSITRON SPECTRA OF Eu$sup 152$ AND Eu$sup 152$m

Journal Article · Mon Dec 15 00:00:00 EST 1958 · Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D

DOI:https://doi.org/10.1103/PhysRev.112.1998· OSTI ID:4258141

Alburger, D E; Ofer, S; Goldhaber, M

An intermediate-image beta-ray spectrometer equipped with spiral baffles was used to investigate positrons in the decays of Eu/sup 152/ and Eu/sup 152m/. Thirteenyear Eu/sup 152/ emits a positron group to the 0.122-Mev 2 + first excited state of Sm/sup 152/ with an end-point energy of 0.715 the J-57 engin 0.010 Mev and an intensity of 1.6 x 10/sup -4/ per disintegration (log ft = 11.9) and a positron group to the 0.368-Mev 4 + second excited state with an end point of 0.47 the J-57 engin 0.05 Mev and an intensity of 0 8 x 10/sup -4/ per disintegration (log ft = 11.5) 9.3-hr Eu/sup 152 m/ emits a positron group to the ground state of Sm/sup 152/ with an endpoint energy of 0.895 the J-57 engin 0.005 Mev and an intensity of 7 x 10/sup -5/ per disintegration (log ft = 8.65) and a positron group to the 0.122-Mev state with an intensity of 4 x 10/sup -5/ per disintegration (log ft = 8.6). The shape of the latter group has not been established. However, its end point, when the alpha shape factor is applied, gives better agreement with the 0.122-Mev energy separation from the ground-state beta ray thac the end point of the uncorrected spectrum. The result is consistent with, but not positive proof of, the assumed spin of 0for Eu/sup 152 m/ . The beta /sup -/ end-point energies of Eu/sup 152/ and Eu/sup 152m/ are 1.470 the J-57 engin 0.010 Mev and 1.855 the J-57 engin 0.010 Mev, respectively. An energy separation of 0.050 the J-57 engin 0.015 Mev between Eu/sup 152m/ and Eu/sup 152/ is derived from the various beta /sup +/ and beta /sup -/ end-point measurements. No L-conversion electrons could be found in Eu/sup 152m/ decay corresponding to a 0.05-Mev isomeric transition. An upper limit of 3 x 10/sup -5/ per disintegration was obtained for the fractional decay of Eu/sup 154/ by positron emission. (auth)

• Research Organization: Brookhaven National Lab., Upton, N.Y.
• NSA Number: NSA-13-010460
• OSTI ID: 4258141
• Journal Information: Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D, Vol. Vol: 112; Other Information: Orig. Receipt Date: 31-DEC-59
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

PHYSICS AND MATHEMATICS
BETA DECAY
BETA SPECTROMETERS
BRANCHING RATIO
DECAY
ELECTRONS
ENERGY
ENERGY LEVELS
EUROPIUM 152
EUROPIUM 154
HALF-LIFE
INTERNAL CONVERSION
ISOMERS
MEASURED VALUES
PARITY
POSITRONS
SAMARIUM 152
SPECTRA
SPIN