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The 68m Cu/ 68 Cu isotope as a new probe for hyperfine studies: The nuclear moments

EPL (Europhysics Letters)

November 2016
115(6):62002

DOI:10.1209/0295-5075/115/62002

Authors:

A.s. Fenta

University of Aveiro

Joao Guilherme Martins Correia

CERN

Monika Stachura

TRIUMF

Show all 19 authorsHide

Time Differential Perturbed Angular Correlation of γ-rays (TDPAC) experiments were performed for the first time in the decay of 68m Cu produced at the ISOLDE facility at CERN. Due to the short half-life of the source isotope, the measurements were carried out online. The intermediate state offers the unique opportunity to study the electromagnetic fields acting at a copper probe in condensed matter via hyperfine interactions. The present work allowed determination of the nuclear moments for this state. The electric quadrupole moment was obtained from an experiment performed in Cu2O and the magnetic dipole moment from measurements in cobalt and nickel foils. The results are discussed in the framework of shell model calculations and the additivity rule for nuclear moments with respect to the robustness of the N = 40 sub-shell.

Decay scheme of 68mCu/⁶⁸Cu. In black are the relevant gamma lines for the TDPAC experiment. Width and length of the arrows are proportional to intensity and energy, respectively.

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Scheme of the experimental PAC set-up online at ISOLDE. The quartz finger (transparent cylinder in the center) and the four cylindrical LaBr3 detectors (38 mm diameter, 38 mm length) surrounding it are shown.

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The R(t) function obtained from the decay of 68mCu implanted in different host materials: a) Cu2O (pellet), b) Co (foil), c) Ni (foil).

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September 2016

EPL, 115 (2016) 62002 www.epljournal.org

doi: 10.1209/0295-5075/115/62002

The 68mCu/68Cu isotope as a new probe for hyperﬁne studies:

The nuclear moments

A. S. Fenta1,2,3, S. Pallada3,4,5,J.G.Correia

3,6,M.Stachura

3,7,K.Johnston

3, A. Gottberg3,7,

A. Mokhles Gerami8,J.R

oder3,9,H.Grawe

10,B.A.Brown

11,U.K

oster12,T.M.Mendonc¸a3,

J. P. Ramos3,13 ,B.A.Marsh

3,T.DayGoodacre

3,14,V.S.Amaral

1,L.M.C.Pereira

M. J. G. Borge3and H. Haas1,3

1Department of Physics and CICECO, University of Aveiro - 3810-193 Aveiro, Portugal

2KU Leuven, Instituut voor Kern- en Stralingsfysica - Celestijnenlaan 200 D, 3001 Leuven, Belgium

3CERN, 1211 Geneva 23, Switzerland

4Department of Chemistry, Faculty of Science, University of Copenhagen - Universitetsparken 5,

2100 Copenhagen, Denmark

5Department of Medicine, Democritus University of Thrace, Alexandroupoli Campus

6 km Alexandroupolis-Makris, 68100 Alexandroupoli, Greece

6Centro de Ciˆencias e Tecnologias Nucleares (C2TN), Instituto Superior T´ecnico, Universidade de Lisboa

2686-953 Sacav´em, Portugal

7TRIUMF - 4004 Wesbrook Mall Vancouver, BC V6T 2A3, Canada

8Department of Physics, K.N.Toosi University of Technology - P.O.Box 15875-4416, Tehran, Iran

9Institute of Physical Chemistry, RWTH-Aachen - Aachen, Germany

10 GSI Helmholtzzentrum f¨ur Schwerionenforschung GmbH - D-64291 Darmstadt, Germany

11 National Superconducting Cyclotron Laboratory and Department of Physics and Astronomy,

Michigan State University - East Lansing, MI 48824-1321, USA

12 Institut Laue-Langevin - 71 avenue des Martyrs, F-38042 Grenoble, France

13 Laboratory of Powder Technology, ´

Ecole Polytechnique F´ed´erale de Lausanne (EPFL) - CH-1015, Switzerland

14 School of Physics and Astronomy, The University of Manchester - Manchester, M13 9PL, UK

received 24 June 2016; accepted in ﬁnal form 6 October 2016

published online 7 November 2016

PAC S 21.10.Ky – Electromagnetic moments

PAC S 23.20.En – Angular distribution and correlation measurements

PAC S 21.60.Cs – Shell model

Abstract – Time Diﬀerential Perturbed Angular Correlation of γ-rays (TDPAC) experiments

were performed for the ﬁrst time in the decay of 68mCu (6−,721 keV,3.75 min) produced at the

ISOLDE facility at CERN. Due to the short half-life of the source isotope, the measurements were

carried out online. The intermediate state (2+,84.1keV,7.84 ns) oﬀers the unique opportunity

to study the electromagnetic ﬁelds acting at a copper probe in condensed matter via hyperﬁne

interactions. The present work allowed determination of the nuclear moments for this state.

The electric quadrupole moment |Q(2+,84.1keV)|=0.110(3) b was obtained from an experiment

performed in Cu2O and the magnetic dipole moment |μ|=2.857(6) μNfrom measurements in

cobalt and nickel foils. The results are discussed in the framework of shell model calculations and

the additivity rule for nuclear moments with respect to the robustness of the N= 40 sub-shell.

editor’s choice Copyright c

EPLA, 2016

Introduction. – Copper (Cu) in its native form is, re-

portedly, the ﬁrst metal to be used by mankind, with me-

chanical, chemical and electronic properties that makes

it, still today, a reference in human activities and wel-

fare. Furthermore, Cu plays a key role in every life

form [1] acting as a cofactor in metabolic enzymes, which

are involved in cellular reparation, respiration or photo-

synthesis [2,3]. In living systems Cu is present in two

oxidation states, Cu(I) and Cu(II), ruling electron trans-

fer in vital redox mechanisms. Due to its unpaired electron

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