Band structure in the neutron-rich lanthanide nucleus [sup 152]Nd. II. Allowed and [ital K]-forbidden transitions from the negative-parity bands

Journal Article · Mon Feb 01 04:00:00 EST 1993 · Physical Review, C (Nuclear Physics); (United States)

DOI:https://doi.org/10.1103/PhysRevC.47.545· OSTI ID:7059278

Hellstroem, M; Mach, H; Fogelberg, B; Jerrestam, D; Spanier, L ^[1]

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1. Department of Neutron Research, University of Uppsala, S-61182 Nykoeping (Sweden)

A fast timing [beta][gamma][gamma]([ital t]) method has been used to measure level lifetimes in [sup 152]Nd as populated in the [beta][sup [minus]] decay of [sup 152]Pr. The following half-lives have been measured: [ital T][sub 1/2]=330(14) and 53(10) ps for the 236.7 keV 4[sub 1][sup +] and the 484.0 keV 6[sub 1][sup +] members of the ground-state band, [ital T][sub 1/2]=145(11), 12(7), and 64(56) ps for the 1542.0 keV 2[sup [minus]], 1600.7 keV 3[sup [minus]], and the 1683.2 keV 4[sup [minus]] members of the [ital K][sup [pi]]=2[sup [minus]] band, and [ital T][sub 1/2]=42(6) and 30(10) ps for the 1827.5 keV 3[sup [minus]] and the 1893.3 keV 4[sup [minus]] members of the [ital K][sup [pi]]=3[sup [minus]] band, respectively. The observed allowed [ital M]1 rates and large hindrance factors for the [ital E]1 transitions deexciting these bands is discussed in terms of [ital K] forbiddenness and the (suggested) dominant two-quasiparticle configurations. Systematics of the octupole vibrational bands in the rare-earth region is examined. The energy minima for the [ital K][sup [pi]]=1[sup [minus]] bands follow a narrow valley along [ital N]=94 associated with the two-quasineutron [l brace][nu]5/2[sup +][642][minus][nu]3/2[sup [minus]][521][r brace] configuration, while minima for the [ital K][sup [pi]]=2[sup [minus]] bands follow narrow valleys at [ital Z]=66 and [ital Z]=74 associated with the two-quasiproton configurations [l brace][pi]7/2[sup [minus]][523][minus][pi]3/2[sup +][411][r brace] and [l brace][pi]9/2[sup [minus]][514][minus][pi]5/2[sup +][402][r brace], respectively. In contrast, the lowering of the [ital K][sup [pi]]=0[sup [minus]] bands near [sup 146]Ba is along both neutron and proton numbers, giving a flat minimum.

• OSTI ID: 7059278
• Journal Information: Physical Review, C (Nuclear Physics); (United States), Journal Name: Physical Review, C (Nuclear Physics); (United States) Vol. 47:2; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

663110* -- General & Average Properties of Nuclei & Nuclear Energy Levels-- (1992-)
663570 -- Nuclear Mass Ranges-- A=150-189-- (1992-)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BETA DECAY
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY
BETA-MINUS DECAY RADIOISOTOPES
COINCIDENCE METHODS
COLLECTIVE EXCITATIONS
COUNTING TECHNIQUES
DECAY
E1-TRANSITIONS
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EVEN-EVEN NUCLEI
EXCITATION
EXCITED STATES
GAMMA CASCADES
INTERMEDIATE MASS NUCLEI
ISOTOPES
LIFETIME
M1-TRANSITIONS
MINUTES LIVING RADIOISOTOPES
MULTIPOLE TRANSITIONS
NEODYMIUM 152
NEODYMIUM ISOTOPES
NUCLEAR CASCADES
NUCLEAR DECAY
NUCLEI
ODD-ODD NUCLEI
PROMETHIUM 152
PROMETHIUM ISOTOPES
RADIOISOTOPES
RARE EARTH ISOTOPES
RARE EARTH NUCLEI
VIBRATIONAL STATES