New computational method to evaluate the 7Li(p,n)7Be reaction near threshold for accelerator-based BNCT and other applications

MARÍA S HERRERA; GUSTAVO A. MORENO; ANDRÉS J. KREINER

Granada

Congreso; 7th Young Researchers Boron Neutron Capture Therapy meeting; 2013

Many potential applications of neutron sources have recently motivated the increase in research and development for accelerator based devices. The endothermal 7Li(p,n)7Be reaction near threshold is of particular interest in Boron Neutron Capture Therapy because low-energy neutrons, suitable for clinical applications (from a few eV to 10 keV), are easily produced. The neutron production near threshold is particularly efficient since it minimizes the necessary proton energy and hence accelerator voltage, the generation of direct and indirect radiation and the volume of the associated beam shaping assembly. This reaction is also useful in a series of different problems, such as the study of quasistellar neutron spectra. Within this context, our work contributes with a new description of the 7Li(p,n)7Be reaction near threshold using center-of-mass and relative coordinates, yielding a mathematical representation which allows a simpler access to all relevant quantities in the reaction and gives new insight into the numerical evaluation problem. The method, implemented as a Ccode, was validated both with numerical and experimental data finding a good agreement. This tool is also used here to analyze scattered published measurements such as (p,n) cross sections, differential and total neutron yields for thick targets. Using these data we derive a consistent set of parameters to evaluate neutron production near threshold.