Background: A Boron Neutron Capture Therapy (BNCT) facility, based on a DT neutron generator, with the final goal to find out a potential, alternative, solution to existing BNCT treatment facilities which are based on nuclear reactors is examined. Materials and Methods: With the aim of the MCNP4B Monte Carlo code different beam-shaping assembly (BSA) configurations were considered. Lead was sel...

We measured the neutron decay lifetime by counting in-beam neutron decay recoil protons trapped in a quasi-Penning trap. The absolute neutron beam fluence was measured by capture in a thin (6)LiF foil detector with known efficiency. The combination of these measurements gives the neutron lifetime: τ n = (886.8 ± 1.2 ± 3.2) s, where the first (second) uncertainty is statistical (systematic) in n...

The r-process is supposed to be a primary process which assembles heavy nuclei from a photo-dissociated nucleon gas. Hence, the reaction flow through light elements can be important as a constraint on the conditions for the r-process. We have studied the impact of di-neutron capture and the neutron-capture of light (Z 10) elements on r-process nucleosynthesis in three different environments: ne...

An apparatus for measuring parity-violating asymmetries in gamma-ray emission following polarized cold neutron capture was constructed as a 1/10th scale test of the design for the forthcoming −→n + p → d + γ experiment at LANSCE. The elements of the polarized neutron beam, including a polarized He neutron spin filter and a radio frequency neutron spin rotator, are described. Using CsI(Tl) detec...

The neutron capture cross section of the unstable nucleus W has been derived from experimental photoactivation data of the inverse reaction W(γ,n)W. The new result of σ = (687 ± 110)mbarn confirms the theoretically predicted neutron capture cross section of W of σ ≈ 700mbarn at kT = 30keV. A neutron density in the classical s-process of nn = (3.8 +0.9 −0.8) × 10 8 cm is derived from the new dat...

Most isotopes of elements with atomic numbers Z > 30 are synthesized via neutron capture reactions. These “n-capture” elements are the majority of the periodic table. In the so-called s-process, neutron fluxes are small enough to allow β-decays to occur between successive neutron captures, and element buildup proceeds along the valley of β-stability. In the r-process, huge but short-lived neutr...

We explore neutrino capture during r-process nucleosynthesis in neutrinodriven ejecta from nascent neutron stars. We focus on the interplay between charged-current weak interactions and element synthesis, and we delineate the important role of equilibrium nuclear dynamics. During the period of coexistence of free nucleons and light and/or heavy nuclei, electron neutrino capture inhibits the r-p...