Eur. Phys. J. A (2014) 50: 93
https://doi.org/10.1140/epja/i2014-14093-x

Regular Article - Theoretical Physics

Production of ⁶He and ⁹Be by radiative capture and four-body recombination

¹ Centro de Física Nuclear, Universidade de Lisboa, Av. Prof. Gama Pinto 2, P-1649-003, Lisboa, Portugal
² Instituto de Estructura de la Materia, CSIC, Serrano 123, E-28006, Madrid, Spain
³ Department of Physics and Astronomy, Aarhus University, DK-8000, Aarhus C, Denmark

^* e-mail: raulez@cii.fc.ul.pt

Received: 1 October 2013
Revised: 29 April 2014
Accepted: 8 May 2014
Published online: 3 June 2014

Abstract

In this work we estimate the production rates for the three-body radiative capture processes α + n + n → ⁶He + γ and α + α + n → ⁹Be + γ, as well as the four-body recombination reactions α + α + n + n → ⁶He + α, ^α + n + n + n → ⁶He + n, α + α + n + n → ⁹Be + n and α + α + α + n → ^BeBe + α. These processes compete as a source of ⁶He and ⁹Be. The hyperspherical adiabatic expansion method is used. With this method no assumption is made about the capture mechanism. Both sequential and direct capture are included. The production rates for the radiative and the four-body recombination processes are found to be comparable for a mass density of about 10⁷g/cm³ ( ∼ 10³⁰ neutrons/cm³) and temperatures of a few GK.