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This presentation gives an overview of thermal cross section measurements at the RPI LINAC. Work discussed includes novel cold moderator capability for use in extending neutron flux down to 0.0005 eV and total thermal neutron cross section measurements performed for polyethylene, polystyrene, Plexiglas (Lucite), and yttrium hydride over the entire thermal region (0.0005 – 1 eV).
This presentation discusses the nuclear data measurements and evaluation work for NCSP, including its objective which is to provide measured and evaluated thermal, resonance, unresolved resonance, and fast region cross-section data to address the priority NCSP nuclear data needs. It also discusses its vision which addresses multiple Nuclear Data 5- and 10-year goals and attributes identified in the NCSP Vision. The intended final product is that rigorous ENDF/B evaluations will be produced from cross section measurements and analyses. Measurement work effort focused on NCSP priorities by NCSP Nuclear Data Advisory Group (NDAG) can be found in Appendix B of the 5-year plan. NCSP measurements program at JRC is now part of the DOE/Euratom agreement, Action Sheet 66.
In the recently released ENDF/B-VIII.0 library, the 35 Cl(n,p) cross section above 100 keV significantly differs from the ENDF/B-VII.0 library. This resulted in large differences in the predicted reactivity in nuclear reactor simulations. The lack of experimental data for incident neutron energies above 100 keV does not allow a precise evaluation of the 35 Cl(n,p) reaction channel. Evaluation of 35 Cl(n,p) cross section was included as one of the highest priorities in recent DOE calls for proposals within the Nuclear Data Interagency Working Group / Research Program.
This presentation states that in comparison to the NJOY-produced multigroup cross sections, the MCNP-produced multigroup cross sections are generally consistent. Statistical uncertainties, however, are challenging and the unresolved resonance region may be looked at in the future. It also discusses how the SPM and LCS options were compared to each other for internal consistency. Additionally, some reactor pin-cell-like problems were used to compare to multigroup capabilities in other Monte Carlo codes (e.g., Serpent, OpenMC).
We report final results for L/T separated pi0 electroproduction cross sections off the proton, the neutron and the deuteron, measured in Hall A of Jefferson Lab. We found a large transverse response for both the proton and neutron cases, pointing to a possible dominance of higher-twist transversity GPD contributions. For the first time, a flavor decomposition of the u and d quark contributions to the cross section will be shown.
ProtoDUNE Single-Phase is a 700-ton liquid argon detector operated in the CERN Neutrino Platform from 2018 to 2020. It is part of the Deep Underground Neutrino Experiment (DUNE), a long-baseline neutrino oscillation experiment with a 40 kT liquid argon far detector to be built at the Sanford Underground Research Facility and a near detector, with both argon and non-argon detector technologies, to be hosted at the Fermi National Accelerator Laboratory. A critical uncertainty to understand in the neutrino oscillation program of DUNE is the uncertainty on final state interactions, either reaction or elastic, of various hadrons on argon since the scattering of neutrino-induced hadrons off argon bias the hadron's measured energy. It can also prevent algorithms from identifying the hadron's particle type. Protons, kaons, and pions from the beam are especially important for the DUNE neutrino program as they represent common final state particles in neutrino interactions off a nucl eus. Therefore, ProtoDUNE is analyzing the test beam data to measure cross sections of pions, protons, and kaons on argon, aiming to tune parameters that model charged particle scattering off argon. This talk will discuss the data-taking program for ProtoDUNE and an overview of the status and results of measuring cross sections of pions, protons, and kaons on argon. It will conclude with a brief overview of how these measurements can be used for future liquid argon neutrino detectors.
A new cold neutron moderator system was developed and constructed at the Rensselaer Polytechnic Institute (RPI) Gaerttner Linear Accelerator. This system was then used to measure the neutron total cross section in the thermal energy range for polyethylene, polystyrene, Lucite, and yttrium hydride. In tandem with these measurements, a fitting procedure was developed at Oak Ridge National Laboratory to vary computationally simulated phonon density of states until a fit with differential and integral data was achieved. This model, combined with the new RPI total cross section data, was used to generate thermal scattering law files for the materials measured at RPI.
The NSLS-II Experimental Tools III (NEXT-III) Project with the goal of building 8-12 new beamlines is ongoing. We were requested to explore the possibility of modifying the long straight section in Cell 26 to accommodate two new undulators for Advanced Nanoscale Imaging (ANI) Beamline and Tender X-ray Nanoprobe (TXN) Beamline. The scope of work includes: linear lattice matching; confirmation of the minimum ID gaps consistent with beam stay-clear limitations; calculation of the X-ray brightness; optimization of the dynamic aperture and momentum acceptance; multi-particle tracking to confirm the injection efficiency does not deteriorate significantly. The beam simulations have to be done using the most recent NSLS-II lattice model with all present insertion devices and realistic magnet errors, misalignments, and apertures. Originally two lattice options were considered for the assessment:1) with single -minimum beta functions and 2) NSLS-II with double-minimum beta functions. However, since the beamlines are not interested in the reduction of the horizontal beta function, just the vertical one, we decided to stop considering the single-minimum option because the current vertical beta is already low (3.3m) and further reducing it at the straight section center can increase it too much at the edge of a long ID, and limit the beam stay-clear. So, this report is focused on the double mini-beta scheme only.
Accelerator-based neutrino facilities represent forefront scientific endeavors, employing state-of-the-art techniques to investigate the properties of neutrinos and unveil signals of physics beyond the standard model. Neutrino-nucleus interactions constitute one of the biggest systematics in these experiments. As neutrino-nucleus cross section measurement statistics have started to surge in recent years, it's becoming vital to control systematics in these measurements. This presentation explores the pivotal role of neutrino interaction uncertainties, including nuclear effects and modeling approximations, in achieving precise neutrino cross-section measurements.
Current and future accelerator neutrino oscillation experiments need neutrino interaction models with smaller systematic uncertainties to resolve much of delta CP phase space. Final state interactions (FSI) and scattering off of correlated nuclei (2p2h) are poorly understood processes that currently contribute large uncertainties to leading models. These processes have proven difficult to study because they often produce relatively low energy nucleons. Protons up to about 100 MeV are below the detection threshold of some accelerator neutrino detectors, and neutrons are usually discounted as undetectable. This poster presents a measurement of the multi-neutron antineutrino cross section at low available energy using the MINERvA detector at Fermilab. This interaction channel is particularly sensitive to FSI and 2p2h interactions. A sideband-driven background constraint that greatly reduces uncertainties on the result will be presented. The measured cross section is compared to GENIE v3 models with different FSI treatments and the SuSA model's 2p2h predictions.
NOvA is a long-baseline neutrino experiment at Fermilab that studies neutrino oscillations via electron neutrino appearance and muon neutrino disappearance. The oscillation measurements compare the Far Detector data to an oscillated prediction informed by the Near Detector (ND) data. This ND-informed prediction is produced from the neutrino generator GENIE, which provides NOvA with a set of interaction uncertainties. However, this coverage does not account for all interaction uncertainties relevant for NOvA, in particular for resonance production (RES) and deep inelastic scattering (DIS) processes, which comprise a substantial portion of NOvA's interactions. Here we introduce six new cross section uncertainties that affect RES and DIS interactions, which represent degrees of freedom not available in the previous NOvA model. After careful studying of their impact, we incorporate them to the NOvA cross-section model. We show the impact of these new uncertainties on various reconstructed quantities.
We perform a single differential $\nu_\mu$ charged current (CC) inclusive cross section measurement in MicroBooNE using improved detector response simulation, reconstruction, and with improved cosmic ray-induced background rejection using an external Cosmic Ray Tagger (CRT). The measurement uses data recorded from Fermilab’s Booster Neutrino Beamline (BNB) between December 2017 and July 2018, corresponding to an integrated protons on target of 7.6e18). We present the results in a similar manner as our previous $\nu_\mu$ charged current (CC) inclusive cross section to allow for direct comparison. The direct comparison highlights two improvements in this measurement over the previous measurement: firstly, the drastically reduced cosmic contamination achieved when using the CRT, and secondly the significantly improved detector modeling, with associated reduced systematic uncertainties. It is shown in this analysis that the outcome is an improved measurement (σ = 0.800 ± 0.030 (stat) ± 0.101 (sys) · 10 -38 cm 2 ) with much smaller uncertainties but a result consistent with that of the previous analysis (σ previous = 0.693 ± 0.010 ± 0.165 · 10 -38 cm 2 ).
MicroBooNE is a Liquid Argon Time Projection Chamber, able to image neutrino interactions with excellent spatial and timing resolution, enabling the identification of complex final states resulting from neutrino-nucleus interactions. This poster will provide an overview of measurements for rare final states, such as and η production. These processes both provide unique sensitivities to the interplay between nucleon-level cross-section physics and nuclear-level physics, as well as account for sources of background in proton decay experiments. Furthermore, this poster showcases MicroBooNE’s measurements of total and first-order differential cross-sections on argon for muon neutrino interactions producing neutral pions in the final-state. These interactions will dominate the event rates observed at forthcoming high-precision neutrino experiments.
We develop hybrid RANS-LES strategies within Nek5000 for application to airfoil sections at small flight configurations. We present a validation and verification study of $k \space – \space \tau$ SST applied to a NACA 0012 wing section in a pure RANS and in a hybrid RANS-LES setup. The study shows good corroboration with existing experimental and numerical datasets. We also analyze some of the observed discrepancies with the experiments by evaluating the side wall “blocking” effect. We demonstrate that for the hybrid turbulence modeling approach a high-order spectral- element discretization converges faster (i.e., with less resolution) than a representative low-order finite-volume-based approach.
Performing a full adjoint simulation in the Integrated Tiger Series (ITS) can be time consuming to obtain statistically significant results. The ray-trace capability in ITS allows for rapid scoping calculations of the uncollided kerma from photon sources without needing to run a full adjoint simulation. However, the uncollided estimate will always underestimate the full-physics kerma since it neglects scattered radiation, and under certain conditions, the result from the capability may not provide a sufficiently accurate estimate of the full-physics kerma. To exemplify the conditions in which the capability provides reasonable estimates, two problem geometries with different materials are simulated using the full adjoint capability as well as the ray-trace capability with a total cross section treatment and a new kerma-attenuation cross-section treatment. The results are then compared to show under which conditions the estimates are accurate. Reasonable estimates are provided from the ray-trace feature when there is minimal scattering into a region of interest occurring, such as with low-Z material and when the photons travel through small amounts of material.
To address the data gap crucial for updating existing viscoplastic constitutive material models for the Class A materials in the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, Section III, Division 5, High Temperature Reactors (ASME, 2023) for inelastic design analysis, Oak Ridge National Laboratory (ORNL) conducted experimental studies on Alloy 800H and Alloy 617 across a range of temperatures up to their maximum temperature limits in Section III, Division 5. The studies aim to characterize the materials' deformation behavior under both strain-controlled mechanical cyclic loading and thermal cycling conditions. This report summarizes ORNL's FY 2024 experimental findings on Alloy 800H and Alloy 617, focusing on pure fatigue tests, cyclic stress-strain curves, thermomechanical fatigue experiments, and verification of the high temperature cyclic damage summation design rules.
The Short-Baseline Near Detector (SBND) is one of the Liquid Argon Time Projection Chamber (LArTPC) neutrino detectors positioned along the axis of the Booster Neutrino Beam (BNB) at Fermilab, and is the near detector in the Short-Baseline Neutrino (SBN) Program. The detector completed commissioning and began taking neutrino data in the summer of 2024. SBND is characterized by superb imaging capabilities and recorded over two million neutrino interactions during its first physics run, which concluded in July 2025. Thanks to its unique combination of measurement resolution and statistics, SBND is carrying out a rich program of neutrino interaction measurements and novel searches for physics beyond the Standard Model (BSM). As the near detector, it will enable the full potential of the SBN sterile neutrino program by performing a precise characterization of the unoscillated event rate and constraining BNB flux and neutrino-argon cross-section systematic uncertainties. In addition, SBND will provide valuable model constraints for DUNE by leveraging the significant overlap in phase space between neutrino interactions in the two experiments. In this talk, I will present the current efforts within the SBND cross section program, discuss their status, and outline the plans for the first physics publications.
urrent and upcoming neutrino experiments at Fermilab will rely on liquid argon time projection chambers (LArTPCs) as the primary detector technology. To reach the ambitious precision required for their physics goals, a detailed understanding of neutrino-argon scattering must be achieved. For the present Short-Baseline Neutrino program, the dominant reaction channel is charged-current muon neutrino interactions leading to mesonless final states with and without protons. Using a large data set of neutrino interactions recorded by the MicroBooNE LArTPC detector at Fermilab, we report progress towards new measurements of differential cross sections in this channel. The analysis leverages multiple event reconstruction paradigms and observables specifically chosen to maximize sensitivity to nuclear effects of interest for improving neutrino scattering models. Related previous cross-section results from MicroBooNE and a preview of what to expect from the new analysis will both be featured in this presentation.