Speaker
Description
Abstract
Neutron production through α-induced nuclear reactions is a key issue in several fields. Specifically, (α,n) reactions are interesting in nuclear astrophysics as a source of neutrons for the slow neutron capture nucleosynthesis (the s-process) [TAI16] and in the α-particles capture process (the α-process) [WOO92, BLI17]. Other fields of interest include the neutron-induced background in underground laboratories [BET10], which is a crucial issue in low counting rate experiments, and in nuclear facilities such as nuclear reactors and particle accelerators [MUR02]. Currently, evaluated data is available only for a limited number of isotopes and the databases present large discrepancies in some cases.
In this work we present the miniBELEN detector, a new modular and transportable neutron counter for (α,n) reactions. This detector has been developed in the context of a Spanish effort for the Measurement of Alpha Neutron Yields and spectra (MANY collaboration). The miniBELEN detector is based on the use of several long 3He-filled proportional neutron counters embedded in a modular high density polyethylene moderator. In order to provide the detector with a response independent of the neutron energy, namely a flat response, an innovative design methodology has been applied. The method is based on the optimization of the contribution of each counter to the total efficiency by using thermal neutron absorbers. This allows to obtain flat responses up to 10 MeV. The experimental characterization of miniBELEN using 252Cf neutron sources and results of the commissioning with the measurement of the 27Al(α,n)30P reaction at Spanish research facilities will be presented.
Acknowledgments
This work has been supported by the Spanish Ministerio de Economía y Competitividad under grants FPA2017-83946-C2-1 & C2-2 and PID2019-104714GB-C21 & C22.
Bibliography
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[WOO92] S.E. Woosley and R.D. Hoffmann, Astrophys. J. 395 (1992) 202 - 239