An innovative methodology has been developed for the procurement of neutron energy distributions from neutron time-of-flight (TOF) measurements with neutron spectrometers. The methodology is based on the accurate determination of the response of the neutron spectrometer via Monte Carlo simulation and an iterative Bayesian unfolding technique for the analysis of the TOF data. The methodology...
The miniBELEN-10A detector is a modular and transportable moderated neutron counter with a nearly flat detection efficiency up to 8 MeV [1]. It is one of the detection systems available for the MANY collaboration (Measurement of Alpha Neutron Yields and Spectra), a Spanish project designed to conduct measurements of (alpha,n) production yields, reaction cross-sections, and neutron energy...
Reactions induced by alpha particles on stable elements play a relevant role in several scientific fields, from nuclear technologies and nuclear astrophysics, to dark matter searches and neutrino physics. Data on neutron yields from the interaction of α-particles with nuclei via (α,n) reactions are of particular interest in this context, both due to the inconsistency of the available...
The reaction plays a crucial role in the nucleosynthesis of heavy elements, in both the main and the weak s processes. In addition, its stellar reaction rate (and that of the competing channel 22Ne(a,g)26Mg ) determine the ratio of the Mg isotopes that can be directly observed in stellar atmospheres. To provide input for stellar and nucleosynthesis models, the cross section needs to be known...
Low energy (α,n) reactions are important for reactor applications and low background experiments. In both cases α-particles, typically of a few MeV, originated from actinides decay present either in reactor fuel and/or in surrounding materials due to the elemental natural abundance. The emitted thus α-particles can induce nuclear reactions on nuclei of wide range of materials introduced in the...
In this work we report on the progress in the R-matrix analysis of the 19F(α,n)22Na reaction at energies above the neutron threshold in the resolved resonance region, using the R-matrix code AZURE2. This reaction has been chosen for re-evaluation because of its importance in applications such as nonproliferation, nuclear astrophysics and low-background experiments. We...
I will present an overview of the new project to measure the (α,n) reactions on light elements, such as 7Li, 10,11B, 13C, and 19F. As an experimental campaign for next 5 years, this study will provide partial, total reaction cross sections, neutron spectra, and gamma- and charged- particle yields. The experiment end station is composed of two...
What we would like to present in this meeting are the results of the latest evaluation of the 17O system. In the calculation of the RAC program, we have added several new sets of integral cross section data and differential cross section data for the 13C(α,n)16O reaction on the basis of the original data. The newly added data also include the latest...
The thick-target neutron spectra from the 13C(α,n0)16O reaction were measured for the energy range of 3.0-6.5 MeV at 10 angles in the laboratory angle interval of 0-150º. The thick target yield was determined by integration of the neutron spectra over the neutron energy range corresponding to the 13C(α,n0)16O reaction followed by integration of the obtained angular distribution of the...
Bayesian methods provide a unifying and powerful framework to quantify uncertainties. Their recent application to R-matrix calculations of nuclear reactions has lent a new level of rigor to R-matrix analyses, accessing new information about R-matrix parameters and assessing the impact of experimental systematics on both estimates of those parameters and R-matrix predictions.
I will begin by...
Recent measurements of the differential cross section of the $^{13}$C$(\alpha,n)^{16}$O reaction have been made at the University of Notre Dame's Nuclear Science Laboratory over an incident laboratory alpha-particle beam energy range from 0.7 to 6.5 MeV. For nuclear astrophysics application, the cross section is desired at $\approx$150~keV and, while the present data is at higher energy, I've...
Accurate assessments of (α, n) neutron production rates, energy spectra, and associated gamma-rays play a crucial role in understanding the underlying backgrounds in experiments dedicated to rare-event searches. This presentation discusses the importance of the radiogenic neutrons within the context of low-background experiments, shedding light on the challenges presented by (α, n) neutrons in...
The sensitivity of underground experiments searching for rare events such as dark matter, proton decay, neutrinoless double-beta decay, and low-energy neutrino physics is often limited by the background caused by neutrons from spontaneous fission and (α,n) reactions.
Neutron yields and energy spectra due to these reactions can be calculated by using a variety of codes. Here we present the...
NeuCBOT, the Neutron Calculator Based On TALYS, is a program for calculating ($\alpha$,n) yields for arbitrary materials given some radioactive contamination. The backbone of the code uses TALYS to calculate ($\alpha$,n) cross sections, SRIM stopping power calculations, and ENDF nuclear decay data. Recent updates to the code include an updated TALYS cross section database, the option to draw...
