Decay studies of neutron deficient nuclei near the Z =64 subshell: sup 142 Dy, sup 140,142 Tb, sup 140,142 Gd, sup 140,142 Eu, sup 142 Sm, and

Journal Article · Fri Mar 01 00:00:00 EST 1991 · Physical Review, C (Nuclear Physics); (USA)

DOI:https://doi.org/10.1103/PhysRevC.43.1066· OSTI ID:6042130

Firestone, R B; Gilat, J; Nitschke, J M; Wilmarth, P A; Vierinen, K S ^[1]

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1. Lawrence Berkeley Laboratory, Berkeley, California 94720 (US)

The electron-capture and {beta}{sup +}-decay branchings (EC/{beta}{sup +}) and delayed proton decays of {ital A}=142 isotopes with 61{le}{ital Z}{le}66 and {ital A}=140 isotopes with 63{le}{ital Z}{le}65 were investigated with the OASIS facility on-line at the Lawrence Berkeley Laboratory SuperHILAC. Electron capture and positron-decay emission probabilities have been determined for {sup 142}Pm and {sup 142}Sm decays, and extensive decay schemes have been constructed for {sup 142}Eu{sup {ital g}}(2.34{plus minus}0.12 s), {sup 142}Gd(70.2{plus minus}0.6 s), {sup 140}Eu(1.51{plus minus}0.02 s), and {sup 140}Gd(15.8{plus minus}0.4 s). Decay schemes for the new isotopes {sup 142}Tb{sup {ital g}}(597{plus minus}17 ms), {sup 142}Tb{sup {ital m}}(303{plus minus}17 ms), {sup 142}Dy(2.3{plus minus}0.3 s), {sup 140}Eu{sup {ital m}}(125{plus minus}2 ms), and {sup 140}Tb(2.4{plus minus}0.2 s) are also presented. We have assigned {gamma} rays to these isotopes on the basis of {gamma}{gamma} and {ital x}{gamma} coincidences, and from half-life determinations. Electron-capture and {beta}{sup +}-decay branchings were measured for each decay, and {beta}-delayed proton branchings were determined for {sup 142}Dy, {sup 142}Tb, and {sup 140}Tb decays. {ital Q}{sub EC} values, derived from the measured EC/{beta}{sup +} branchings and the level schemes are compared with those from the Wapstra and Audi mass evaluation and the Liran and Zeldes mass calculation. The systematics of the {ital N}=77 isomer decays are discussed, and the intense 0{sup +}{r arrow}1{sup +} and 1{sup +}{r arrow}0{sup +} ground-state beta decays are compared with shell-model predictions for simple spin-flip transitions.

• DOE Contract Number: AC03-76SF00098
• OSTI ID: 6042130
• Journal Information: Physical Review, C (Nuclear Physics); (USA), Vol. 43:3; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
DYSPROSIUM 142
ENERGY LEVELS
EUROPIUM 140
EUROPIUM 142
GADOLINIUM 140
GADOLINIUM 142
PROMETHIUM 142
BETA-PLUS DECAY
ELECTRON CAPTURE DECAY
SAMARIUM 142
TERBIUM 140
BRANCHING RATIO
COINCIDENCE SPECTROMETRY
HALF-LIFE
BETA DECAY
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
DECAY
DYSPROSIUM ISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
EUROPIUM ISOTOPES
EVEN-EVEN NUCLEI
GADOLINIUM ISOTOPES
HOURS LIVING RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
ISOTOPES
NUCLEAR DECAY
NUCLEI
ODD-ODD NUCLEI
PROMETHIUM ISOTOPES
RADIOISOTOPES
RARE EARTH ISOTOPES
RARE EARTH NUCLEI
SAMARIUM ISOTOPES
SECONDS LIVING RADIOISOTOPES
TERBIUM ISOTOPES
651720* - Nuclear Properties & Reactions
A=90-149
Experimental