The ideal neutron energy spectrum of 241AmLi(α,n)10B sources

The pure and unperturbed (ideal, at birth) spectra of 241AmLi(α,n)10B sources were determined using Monte Carlo simulations, along with the neutron spectrum measured outside a source's encapsulation. Various parameters that affect photon and neutron yields and energy distributions were investigated. The source's microparticle size was deduced. Subsequently, the calculated theoretical neutron energy spectra of the 241AmLi(α,n) reaction were compared to both the ideal spectra and the calculation of Geiger and van der Zwan predominantly used since early 1970s. ► A new Monte Carlo based method is applied to obtain the unperturbed (at birth) 241AmLi spectrum. ► Various parameters that affect photon and neutron yields and energy distributions are investigated. ► The μ-particle size of neutron sources is investigated and deduced for an actual source.