A Method to Obtain a Maxwell-Boltzmann Neutron Spectrum at kT = 30 keV for Nuclear Astrophysics Studies

A method to shape the neutron energy spectrum at low-energy accelerators is proposed by modification of the initial proton energy distribution. A first application to the superconductive RFQ of the SPES project at Laboratori Nazionali di Legnaro is investigated for the production of a Maxwell-Boltzmann neutron spectrum at kT = 30 keV via the ⁷Li(p, n)⁷Be reaction. Concept, solutions and calculations for a setup consisting of a proton energy shaper and a lithium target are presented. It is found that a power dentisity of 3 kW cm^-2 could be sustained by the lithium target and a forward-directed neutron flux higher than 10¹⁰ s^-1 at the sample position could be obtained. In the framework of the SPES project the construction of a LEgnaro NeutrOn Source (LENOS) for Astrophysics and for validation of integral nuclear data is proposed, suited for activation studies on stable and unstable isotopes.