Low-lying E1 transitions in the stable even Sm isotopes

Journal Article · Sun Aug 01 04:00:00 EDT 1976 · Phys. Rev., C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.14.543· OSTI ID:7266702

Metzger, F R

Strong resonant scattering of bremsstrahlung by a level in /sup 144/Sm at 3.225-MeV excitation energy has been observed. Angular distribution and linear polarization measurements have led to a 1/sup -/ assignment for this level. From a self-absorption study, a value GAMMA/sub 0/ = 220 +- 30 meV has been obtained for the partial radiative width of the ground-state transition. For the known 1/sup -/ states in /sup 150/Sm (1.166 MeV) and /sup 154/Sm (0.921 MeV), partial widths GAMMA/sub 0/(1.166) = (5.4 +- 0.4) meV, and GAMMA/sub 0/(0.921) = (7.4 +- 1.0) meV were measured. Combining the results of bremsstrahlung measurements with those of previous resonance fluorescence experiments utilizing high-speed rotation of radioisotopes, a width GAMMA/sub 0/ = (3.1 +- 0.4) meV was arrived at for the ground-state transition from the 1.465-MeV 1/sup -/ state in /sup 148/Sm. The excitation energies of the 1/sup -/ states studied in the even Sm isotopes below N = 89 are fairly close to the sum (E (2/sup +//sub 1/) + E (3/sup -//sub 1/)). The B (E1)'s initially decrease as one moves away from the deformed region. While this is not unexpected, the reversal of this trend near and at the magic neutron number N = 82, as evidenced by the large B (E1) observed in /sup 144/Sm and the behavior of the B (E1)'s in /sup 142/,/sup 144/Nd, is somewhat surprising. (AIP)

• Research Organization: Bartol Research Foundation of The Franklin Institute, Swarthmore, Pennsylvania 19081
• OSTI ID: 7266702
• Journal Information: Phys. Rev., C; (United States), Journal Name: Phys. Rev., C; (United States) Vol. 14:2; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

651723* -- Nuclear Properties & Reactions
A=90-149
Experimental-- Energy Levels & Transitions-- (-1987)
651725 -- Nuclear Properties & Reactions
A=90-149
Experimental-- Nuclear Reactions & Scattering-- (-1987)
651823 -- Nuclear Properties & Reactions
A=150-189
Experimental-- Energy Levels & Transitions-- (-1987)
651825 -- Nuclear Properties & Reactions
A=150-189
Experimental-- Nuclear Reactions & Scattering-- (-1987)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ANGULAR DISTRIBUTION
ANGULAR MOMENTUM
BREMSSTRAHLUNG
CROSS SECTIONS
DISTRIBUTION
ELECTROMAGNETIC RADIATION
ENERGY RANGE
ENERGY-LEVEL TRANSITIONS
EVEN-EVEN NUCLEI
GAMMA SPECTRA
INELASTIC SCATTERING
INTERMEDIATE MASS NUCLEI
ISOTOPES
LEVEL WIDTHS
MEV RANGE
MEV RANGE 01-10
NUCLEAR REACTIONS
NUCLEI
PARITY
PARTICLE PROPERTIES
PHOTONUCLEAR REACTIONS
RADIATIONS
RARE EARTH ISOTOPES
RARE EARTH NUCLEI
RESONANCE SCATTERING
SAMARIUM 144
SAMARIUM 144 TARGET
SAMARIUM 148
SAMARIUM 148 TARGET
SAMARIUM 150
SAMARIUM 150 TARGET
SAMARIUM 154
SAMARIUM 154 TARGET
SAMARIUM ISOTOPES
SCATTERING
SPECTRA
STABLE ISOTOPES
TARGETS