Eur. Phys. J. A (2012) 48: 144
https://doi.org/10.1140/epja/i2012-12144-0

Regular Article - Experimental Physics

Preparation and characterisation of isotopically enriched Ta₂O₅ targets for nuclear astrophysics studies

¹ INFN, Sezione di Padova, via Marzolo 8, 35131, Padova, Italy
² INFN, Laboratori Nazionali di Legnaro, Legnaro, Italy
³ SUPA, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
⁴ Dipartimento di Scienze Fisiche, Università di Napoli “Federico II”, and INFN, Sezione di Napoli, Napoli, Italy
⁵ INFN, Laboratori Nazionali del Gran Sasso, Assergi, Italy
⁶ Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
⁷ Dipartimento di Fisica, Università di Genova, and INFN, Genova, Italy
⁸ Università degli Studi di Milano and INFN, Sezione di Milano, Milano, Italy
⁹ Dipartimento di Fisica e Astronomia, Università di Padova, and INFN, Via Marzolo 8, Padova, Italy
¹⁰ Institute of Nuclear Research (ATOMKI), Debrecen, Hungary
¹¹ Dipartimento di Fisica Sperimentale, Università degli Studi di Torino, and INFN, Sezione di Torino, Torino, Italy
¹² MATIS-IMM-CNR at Dipartimento di Fisica e Astronomia, Università di Padova, Via Marzolo 8, Padova, Italy
¹³ Institut für Experimentalphysik III, Ruhr-Universität Bochum, Bochum, Germany
¹⁴ Osservatorio Astronomico di Collurania, Teramo, and INFN, Sezione di Napoli, Napoli, Italy
¹⁵ Seconda Università di Napoli, Caserta, and INFN, Sezione di Napoli, Napoli, Italy

^* e-mail: caciolli@pd.infn.it

Received: 16 April 2012
Revised: 13 September 2012
Accepted: 28 September 2012
Published online: 24 October 2012

Abstract

The direct measurement of reaction cross-sections at astrophysical energies often requires the use of solid targets of known thickness, isotopic composition, and stoichiometry that are able to withstand high beam currents for extended periods of time. Here, we report on the production and characterisation of isotopically enriched Ta₂O₅ targets for the study of proton-induced reactions at the Laboratory for Underground Nuclear Astrophysics facility of the Laboratori Nazionali del Gran Sasso. The targets were prepared by anodisation of tantalum backings in enriched water (up to 66% in ¹⁷O and up to 96% in ¹⁸O. Special care was devoted to minimising the presence of any contaminants that could induce unwanted background reactions with the beam in the energy region of astrophysical interest. Results from target characterisation measurements are reported, and the conclusions for proton capture measurements with these targets are drawn.