[beta][sup +] decay and cosmic-ray half-life of [sup 91]Nb

Journal Article · Tue Jun 01 00:00:00 EDT 1993 · Physical Review, C (Nuclear Physics); (United States)

DOI:https://doi.org/10.1103/PhysRevC.47.2598· OSTI ID:6497661

Hindi, M M; Sur, B; Wedding, K L; Bardayan, D W; Czerwinski, K R; da Cruz, M T.F.; Hoffman, D C; Larimer, R; Lesko, K T; Norman, E B ^[1]

---

1. Physics Department, Tennessee Technological University, Cookeville, Tennessee 38505 (United States) Nuclear Science Division, Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States) Physics Department, Queen's University, Kingston, Ontario, K7L 9N6 (Canada)

In the laboratory, [sup 91]Nb decays by electron capture with a 680-yr half-life. However, as a high energy cosmic ray, it would be stripped of its atomic electrons and would be able to undergo only [beta][sup +] decay. We produced and chemically purified a sample of [sup 91]Nb and observed its decay with an array of Ge and NaI detectors. By following the [beta][sup +] annihilation radiation, we were able to determine the [beta][sup +] branching ratios of both the 105-keV, 61-d isomer and the ground state of [sup 91]Nb. The ground-state branch is (7.7[plus minus]0.8)[times]10[sup [minus]3]% leading to a [beta][sup +] partial half-like of (8.8[plus minus]1.9)[times]10[sup 6] yr. Such a value of the half-life makes [sup 91]Nb a good candidate for determining the confinement time of this secondary component of the cosmic rays.

• DOE Contract Number: FG05-87ER40314; AC03-76SF00098
• OSTI ID: 6497661
• Journal Information: Physical Review, C (Nuclear Physics); (United States), Vol. 47:6; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
NIOBIUM 91
BETA-PLUS DECAY
BRANCHING RATIO
HALF-LIFE
BETA DECAY
BETA DECAY RADIOISOTOPES
DAYS LIVING RADIOISOTOPES
DECAY
ELECTRON CAPTURE RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
NIOBIUM ISOTOPES
NUCLEAR DECAY
NUCLEI
ODD-EVEN NUCLEI
RADIOISOTOPES
YEARS LIVING RADIOISOTO
YEARS LIVING RADIOISOTOPES
663210* - Ground-State Radioactivity- (1992-)
663560 - Nuclear Mass Ranges- A=90-149- (1992-)