https://doi.org/10.1051/epjconf/201714601007
Time-of-flight and activation experiments on 147Pm and 171Tm for astrophysics
1 Universidad de Sevilla, Sevilla, Spain
2 Instituto de Fisica Corpuscular IFIC, Valencia, Spain
3 Universitat Politecnica de Catalunya UPC, Barcelona, Spain
4 Paul Scherrer Institute PSI, Villigen, Switzerland
5 Soreq Nuclear Research Center, Yavne, Israel
6 Institut Laue-Langevin ILL, Grenoble, France
7 Hebrew University, Jerusalem
8 European Organization for Nuclear Research (CERN), Switzerland
9 University of Lodz, Poland
10 Institut de Physique Nucléaire, CNRS-IN2P3, Univ. Paris-Sud, Université Paris-Saclay, 91406 Orsay Cedex, France
11 Technische Universität Wien, Austria
12 CEA Saclay, Irfu, Gif-sur-Yvette, France
13 Centro de Investigaciones Energeticas Medioambientales y Tecnológicas (CIEMAT), Spain
14 Istituto Nazionale di Fisica Nucleare, Sezione di Bari, Italy
15 Charles University, Prague, Czech Republic
16 University of Manchester, UK
17 University of Zagreb, Croatia
18 University of York, UK
19 University of Santiago de Compostela, Spain
20 INFN Laboratori Nazionali del Sud, Catania, Italy
21 Dipartimento di Fisica, Università degli Studi di Bari, Italy
22 Instituto Superior Técnico, Lisbon, Portugal
23 Goethe University Frankfurt, Germany
24 Horia Hulubei National Institute of Physics and Nuclear Engineering, Romania
25 Japan Atomic Energy Agency (JAEA), Tokai-mura, Japan
26 European Commission, Joint Research Centre, Geel, Retieseweg 111, 2440 Geel, Belgium
27 Karlsruhe Institute of Technology, Campus North, IKP, 76021 Karlsruhe, Germany
28 National Technical University of Athens, Greece
29 School of Physics and Astronomy, University of Edinburgh, UK
30 Agenzia nazionale per le nuove tecnologie (ENEA), Bologna, Italy
31 Istituto Nazionale di Fisica Nucleare, Sezione di Bologna, Italy
32 Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig, Germany
33 Dipartimento di Fisica e Astronomia, Università di Bologna, Italy
34 Istituto Nazionale di Fisica Nucleare, Sezione di Legnaro, Italy
35 Consiglio Nazionale delle Ricerche, Bari, Italy
36 Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, Italy
37 Dipartimento di Fisica e Astronomia, Università di Catania, Italy
38 University of Ioannina, Greece
39 University of Vienna, Faculty of Physics, Vienna, Austria
40 University of Granada, Spain
41 Department of Physics, University of Basel, Switzerland
42 Centre for Astrophysics Research, University of Hertfordshire, UK
43 Bhabha Atomic Research Centre (BARC), India
44 Australian National University, Canberra, Australia
a e-mail: cguerrero4@us.es
Published online: 13 September 2017
The neutron capture cross section of several key unstable isotopes acting as branching points in the s-process are crucial for stellar nucleosynthesis studies, but they are very challenging to measure due to the difficult production of sufficient sample material, the high activity of the resulting samples, and the actual (n,γ) measurement, for which high neutron fluxes and effective background rejection capabilities are required. As part of a new program to measure some of these important branching points, radioactive targets of 147Pm and 171Tm have been produced by irradiation of stable isotopes at the ILL high flux reactor. Neutron capture on 146Nd and 170Er at the reactor was followed by beta decay and the resulting matrix was purified via radiochemical separation at PSI. The radioactive targets have been used for time-of-flight measurements at the CERN n_TOF facility using the 19 and 185 m beam lines during 2014 and 2015. The capture cascades were detected using a set of four C6D6 scintillators, allowing to observe the associated neutron capture resonances. The results presented in this work are the first ever determination of the resonance capture cross section of 147Pm and 171Tm. Activation experiments on the same 147Pm and 171Tm targets with a high-intensity 30 keV quasi-Maxwellian flux of neutrons will be performed using the SARAF accelerator and the Liquid-Lithium Target (LiLiT) in order to extract the corresponding Maxwellian Average Cross Section (MACS). The status of these experiments and preliminary results will be presented and discussed as well.
© The Authors, published by EDP Sciences, 2017
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
