Measurements of conversion electrons in the s-process branching point nucleus 176Lu

A. Battaglia; W. Tan; R. Avetisyan; C. Casarella; A. Gyurijinyan; K. V. Manukyan; S. T. Marley; A. Nystrom; N. Paul; K. Siegl; K. Smith; M. K. Smith; S. Y. Strauss; A. Aprahamian

doi:10.1140/epja/i2016-16126-x

EPJ

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2023 Impact factor 2.6

Hadrons and Nuclei

Eur. Phys. J. A (2016) 52: 126
https://doi.org/10.1140/epja/i2016-16126-x

Regular Article - Experimental Physics

Measurements of conversion electrons in the s-process branching point nucleus ¹⁷⁶Lu

A. Battaglia^*, W. Tan, R. Avetisyan, C. Casarella, A. Gyurijinyan, K. V. Manukyan, S. T. Marley, A. Nystrom, N. Paul, K. Siegl, K. Smith, M. K. Smith, S. Y. Strauss and A. Aprahamian

Department of Physics, University of Notre Dame, 46556, Notre Dame, IN, USA

^* e-mail: abattagl@nd.edu

Received: 22 December 2015
Revised: 6 March 2016
Accepted: 10 March 2016
Published online: 12 May 2016

Abstract

Conversion coefficients, gamma-gamma and gamma-electron coincidences were measured in the s-process branching point nucleus ¹⁷⁶Lu . Our goal was to determine the multipolarities of the $\gamma$ -ray transitions that connect the high and low K states of ¹⁷⁶Lu . This ¹⁷⁶Lu nucleus has a long-lived ground state ( $K=7^{-}$ of 37.6Gy, a short-lived isomeric state ( $K=0^{-}$ at 122.8keV with half-life of 3.6h, as well as a 58μs isomer at 1588keV ( $K=14^{+}$ . The excitation structure of this nucleus contains bands of intermediate spins of both positive and negative parities. The intermediate states can under certain stellar temperatures completely change the equilibrium between the isomer and ground state of ¹⁷⁶Lu and change the abundance of this nucleus. We populated 37 previously known levels in this nucleus via the ¹⁷⁶Yb (p, n reaction and measured 42 conversion coefficients for $\gamma$ -ray transitions including 17 of them for the first time.