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DOE OSTI2026

Track Matching in the DUNE Near Detectors

The Deep Underground Neutrino Experiment (DUNE) is an international particle physics experiment looking answer some of the largest unanswered questions in neutrino physics. DUNE uses a high power neutrino beam produced at Fermi National Accelerator Laboratory (Fermilab), and consists of a near detector (ND) also located at Fermilab and a far detector (FD) 1300 km away at the Sanford Underground Research Facility (SURF) in South Dakota. In the first phase of the experiment, the ND complex will contain a modular liquid argon TPC (ND-LAr) and a solid scintillator-based muon spectrometer (TMS), in addition to a beam monitoring detector (SAND) and systems for moving ND-LAr and TMS away from the neutrino beam axis (PRISM). A prototype of ND-LAr, the 2x2 demonstrator, alongside a solid scintillator muon tagger provided by repurposed MINERvA planes, has been built and taken data at Fermilab. For analyses with the ND, connecting particle tracks (such as muons) that exit the liquid argon active volume into the solid scintillator muon detector can improve particle identification and energy reconstruction, and alleviate pileup due to the intense beam. To match tracks between detectors during reconstruction, we have explored using Graph Neural Networks (GNNs) to connect tracks segments between the liquid argon detector region and the solid scintillator detector planes. We have trained a GNN on reconstructed simulated data from the 2×2 demonstrator and repurposed MINERvA planes. We will evaluate its performance and then train a similar network on reconstructed ND-LAr and TMS simulations.

Xing, Daniel [U. Colorado, Boulder]↗

NASA NTRS1991

Software For Multivariable Frequency-Domain Analysis

FREQ (Multivariable Frequency Domain Singular Value Analysis Package) software package of subroutines performing frequency-domain analysis of: continuous- or discrete-multivariable linear systems; any continuous system for which one calculates transfer matrix at points on imaginary axis; or any discrete system for which one calculates transfer matrix at points on unit circle. Four different versions available. Single-precision brief version LAR-14119, single-precision complete version LAR-14120, double-precision brief version LAR-14121, and double-precision complete version LAR-14122. Written in ANSI standard FORTRAN 77.

Armstrong, Ernest S.↗

NASA NTRS2009

LU-HF Age of Martian Meteorite Larkman Nunatek 06319

Lu-Hf isotopic data were collected on mineral separates and bulk rock powders of LAR 06319, yielding an age of 197+/- 29 Ma. Sm-Nd isotopic data and in-situ LA-ICP-MS data from a thin section of LAR 06319 are currently being collected and will be presented at the 2009 LPSC. These new data for LAR 06319 extend the existing data set for the enriched shergottite group. Martian meteorites represent the only opportunity for ground truth investigation of the geochemistry of Mars [1]. At present, approximately 80 meteorites have been classified as Martian based on young ages and distinctive isotopic signatures [2]. LAR 06319 is a newly discovered (as part of the 2006 ANSMET field season) martian meteorite that represents an important opportunity to further our understanding of the geochemical and petrological constraints on the origin of Martian magmas. Martian meteorites are traditionally categorized into the shergottite, nakhlite, and chassignite groups. The shergottites are further classified into three distinct isotopic groups designated depleted, intermediate, and enriched [3,4] based on the isotope systematics and compositions of their source(s).

Shafer, J. T.↗

NASA NTRS2013

Petrography and Geochemistry of Feldspathic Lunar Meteorite Larkman Nunatak 06638

LAR 06638 is a glassy-matrix lunar regolith breccia based on the presence of glass spherules, which also contains prominent clasts of a feldspathic fragmental breccia lithology. The similarity in composition of the two lithologies is unsurprising given the observed similarities in the clast populations and mineral compositions in both lithologies. The small differences in composition are likely explained by the incorporation of small amounts of more diverse material into the regolith breccia lithologies, e.g., KREEPy glass clasts to account for the higher siderophile and ITE concentrations and excess plagioclase to account for the lower concentrations of mafic elements and increased Na concentrations. Given the relatively small masses analyzed (approx.120 mg of each lithology), these small compositional differences could also be sampling effects. The presense of multiple generations of glass coatings on LAR 06638 is, to our knowledge, unique among lunar meteorites. The more mafic, schlieren and nanophase Fe bearing glass is similar in morphology to the South Ray Crater glass coatings at the Apollo 16 site [3] and likely has a similar origin. The outer, more feldspathic glass has a morphology typical of fusion crust observed on other feldspathic lunar meteorites. It is unclear at this time whether the partially melted glass area represents a partially formed fusion crust or incipient melting due to heating on the lunar surface, likely from an overlying (and possibly ablated) glass splash coating. LAR 06638 is unlikely to be source-crater paired with any other lunar meteorites. For all elements, it plots right in the range of "typical feldspathic lunar meteorites" [4]. Among lunar meteorites from Antarctica, LAR 06638 most closely resembles MAC 88104/5 in composition, although it is slightly more feldspathic and 1.8 richer in siderophile elements. Compositionally it is more similar to hot-desert meteorites like Dhofar 490/1084 and NWA 2200 [4].

Zeigler, Ryan A.↗

DOE OSTI2024

Overview of collaborative research between UNICAMP in Brazil and Fermilab in cryogenics

The Long-Baseline Neutrino Facility (LBNF) situated at the Sanford Underground Research Facility (SURF) in Lead, South Dakota, serves as the host for the Deep Underground Neutrino Experiment (DUNE), employing cryostats with nearly 70,000 metric tons of high purity liquid argon (LAr). The integrity of LAr quality is pivotal in determining the electron lifetime within DUNE, directly impacting its signal-to-noise ratio. Specifically, Far Detector 1 (FD-1) in cryostat 1 requires an electron lifetime over 3 ms within its 3.5 m drift, corresponding to less than 100 parts-per-trillion (ppt) Oxygen equivalent contamination. Far Detector 2 (FD-2) in cryostat 2 demands over 6 ms electron lifetime within its 6.0 m drift, corresponding to less than 50 ppt Oxygen equivalent contamination. Nitrogen (N$_2$) absorption of LAr scintillation light, known as quenching, necessitates N$_2$ contamination in LAr to remain below 1 ppm to minimize photon loss and enhance energy reconstruction. Studies indicate that at 1 ppm N$_2$, approximately 20% of scintillation light is lost, highlighting the importance of minimizing N$_2$ contamination.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

DOE OSTI2025

Identification of the Liquid Argon Scattering Experimental Discrepancies Using Simulation

Scintillation light analysis in liquid argon based neutrino detectors is restrained in capability due to uncertainty in fundamental constants critical to the analysis process. One such property is the Rayleigh scattering length of liquid argon. In the fall of 2023, the TallBo cryostat, located in the Proton Assembly Building at Fermilab, was used to study the scattering length of liquid argon in the Liquid Argon Scattering (LArS) experiment. Due to systematic errors unknown during measurement analysis, LArS’s measurements were quite uncertain. By simulating the LArS experiment, we found that the downturn in detector count rate as a function of liquid argon height at low heights was caused by a misplaced photo multiplier. With concentrated effort, we may be able to successfully correct this effect by understanding the relationship between the specified Rayleigh scattering length and the measured attenuation length. With this information and further progression in analysis, we may be able to extract corrected measurements from the LArS data and attain a tangible experimental measurement of the scattering length of liquid argon.

Breaux, Auto D. [Tulane U.; Fermilab]↗

DOE OSTI2020

Differences in the response of two light guide technologies and two readout technologies after an exchange of liquid argon in the dewar

In this investigation the response to the scintillation light generated by through-going cosmic muons in liquid argon (LAr) was measured by two light guide technologies and two readout technologies after five weeks of running in the TallBo dewar at Fermilab. The response was remeasured after the dewar was drained of LAr, refilled, and then run again for an additional four weeks. After the dewar was refilled, there was clear evidence that the scintillation signal had dropped significantly. The two light guide technologies were developed at Indiana University and MIT/Fermilab. The two readout technologies were boards that passively or actively ganged 12 Hamamatsu MPPCs. Two possible explanations were identified for the degraded signal: the response of the two light guide technologies degraded due to damage caused by thermal cycling, and/or unknown differences in the trace residual Xe contamination in the fills of LAr led to the observed drop in scintillation light. Neither absorption nor quenching by N 2 , O 2 , and H 2 O contamination can account for the degradation. Neither the individual Hamamatsu MPPCs nor the passive/active ganging boards appear to have been affected by the thermal cycling. The path length distributions of the cosmics traversing the dewar appear quite similar in both event samples.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

DOE OSTI2021

Xenon doping of Liquid Argon in ProtoDUNE Single Phase: first results

Doping Liquid Argon (LAr) with xenon is a known technique to shift the light emitted by argon (128 nm) to a longer wavelength to ease its detection. The largest Xenon doping test ever performed in a LArTPC was carried out in ProtoDUNE Single Phase (ProtoDUNE-SP) at the CERN Neutrino Platform. The response of such a large TPC (7701 of Liquid Argon and 4401 of fiducial mass) has been studied using the ProtoDUNE Photon Detection System (PDS) and a dedicated setup installed before the run. With the first, it was possible to study the light detected in the system as a function of the xenon concentration and to characterise the light collection efficiency with respect to the track position. With the second system it was possible to disentangle the LAr (128 nm) light from the xenon (178 nm) light using two dedicated X-ARAPUCA modules. The run was fully satisfactory, it was possible to measure directly the increase of the xenon light component during doping; furthermore most of the LAr light quenched by impurities was fully recovered even at small Xenon concentration (< 20 ppm in mass). A study of the collected scintillation light as a function of the track position showed an improvement of the detector response uniformity.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

DOE OSTI2020

Study of space charge in the ICARUS T600 detector

The accumulation of positive ions, produced by ionizing particles crossing Liquid Argon Time Projection Chambers (LAr-TPCs), may generate distortions of the electric drift field affecting the track reconstruction of the ionizing events. These effects could become relevant for large LAr-TPCs operating at surface or at shallow depth, where the detectors are exposed to a copious flux of cosmic rays. We report a detailed study of such possible field distortions in the ICARUS T600 LAr-TPC has been performed analyzing a sample of cosmic muon tracks recorded with one T600 module operated at surface in 2001. The maximum track distortion turns out to be of few mm in good agreement with the prediction by a numerical calculation. As a cross-check, the same analysis has been performed on a cosmic muon sample recorded during the ICARUS T600 run at the LNGS underground laboratory, where the cosmic ray flux was suppressed by a factor $\sim 10^6$ by 3400 m water equivalent shielding. No appreciable distortion has been observed, confirming that the effects measured on surface are actually due to ion space charge.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

DOE OSTI2026

LBNF/DUNE Liquid Argon Roadmap

The Deep Underground Neutrino Experiment (DUNE) is an international flagship venture to unlock the mysteries of neutrinos. Hosted at the Sanford Underground Research Facility (SURF) and supported by the Long-Baseline Neutrino Facility (LBNF), DUNE relies on nearly 75,000 tonnes of ultrapure liquid argon (LAr) housed in state-of-the-art cryostats. Transporting such vast quantities of LAr to its destination a mile underground in Lead, SD, is a logistical and engineering challenge. The process begins with securing large quantities of liquid argon from suppliers located far from the site, with major sources situated near Houston, TX and Chicago, IL. The receiving facility, located atop a mountain with steep, often snow-covered access roads, provides limited maneuverability for trucks and can only handle two deliveries simultaneously. The facility serves as an entry point for argon to the greater LBNF cryogenic system. It is furnished with truck unloading stations, limited buffer storage of some 280 tonnes capacity, and vaporizers. The last are crucial for converting liquid argon into gas for transfer down the Ross Shaft, eliminating the need for cryogens in the vertical pipeline. These constraints, along with other operational factors, cap the delivery rate at 70 tonnes per day. Once underground, the argon is purified and recondensed before filling the cryostats. This roadmap outlines the integrated supply chain and cryogenic systems that enable the delivery of LAr to support DUNE’s groundbreaking physics research.

Maciazka, Matt [Fermilab]↗

DOE OSTI2021

Improved age- and gender-specific radiation risk models applied on cohorts of Swedish patients

The aim of this study is to implement lifetime attributable risk (LAR) predictions for radiation induced cancers for Swedish cohorts of patients of various age and sex, undergoing diagnostic investigations by nuclear medicine methods. Methods: Calculations are performed on Swedish groups of patients with Paget's disease and with bone metastases from prostatic cancer and diagnosed with bone scintigraphy with an administration of 500 MBq 99m Tc-phosphonate. Results: The inclusion of patient survival rates into the calculations lowers the induced radiation cancer risk, as it takes into account that cohorts of patients have shorter predicted survival times than the general population. Conclusion: LAR estimations could be valuable for referring physicians, nuclear medicine physicians, nurses, medical physicists, radiologists, and oncologists and as well as ethical committees for risk estimates for specific subgroups of patients. Caution is however advised with respect to application of LAR predictions to individuals (because of individual sensitivities, circumstances, etc.).

61 RADIATION PROTECTION AND DOSIMETRY↗

DOE OSTI2022

First Leptophobic Dark Matter Search from the Coherent–CAPTAIN-Mills Liquid Argon Detector

We report the first results of a search for leptophobic dark matter (DM) from the Coherent–CAPTAIN-Mills (CCM) liquid argon (LAr) detector. An engineering run with 120 photomultiplier tubes (PMTs) and 17.9 × 10 20 protons on target (POT) was performed in fall 2019 to study the characteristics of the CCM detector. The operation of this 10-ton detector was strictly light based with a threshold of 50 keV and used coherent elastic scattering off argon nuclei to detect DM. Despite only 1.5 months of accumulated luminosity, contaminated LAr, and nonoptimized shielding, CCM’s first engineering run has already achieved sensitivity to previously unexplored parameter space of light dark matter models with a baryonic vector portal. With an expected background of 115 005 events, we observe 115 005 + 16.5 events which is compatible with background expectations. For a benchmark mediator-to-DM mass ratio of m V B =m χ = 2.1, DM masses within the range 9 MeV ≲ m χ ≲ 50 MeV are excluded at 90% C. L. in the leptophobic model after applying the Feldman-Cousins test statistic. CCM’s upgraded run with 200 PMTs, filtered LAr, improved shielding, and 10 times more POT will be able to exclude the remaining thermal relic density parameter space of this model, as well as probe new parameter space of other leptophobic DM models.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2020

Development of Dry Cask Risk Tools

The Nuclear Regulatory Commission (NRC) has repeatedly expressed a desire to increase the use of risk in its decision-making. The Probabilistic Risk Assessment (PRA) Policy Statement published in 1995 formalized the Commission’s commitment to risk-informed regulation through the expanded use of PRA. While a great deal of work has been done to incorporate risk insights into the regulatory framework for at-power nuclear reactors. Far less progress has been made to risk inform the dry-casks and nuclear waste transportation areas of the nuclear fuel cycle. INL was tasked with incorporating the information from the two completed dry cask PRAs as well as any additional available information into a tool that helps the NRC use those insights to identify levels of risk at various stages in the nuclear waste cycle. The first task was to address the License Amendment Request (LAR) Process for Dry Cask storage, the second task is for the incorporate transportation into the tool, and the third and final task will be incorporate any additional regulatory applications for dry cask storage. This report covers the first task of the tool and will eventually incorporate the remaining two tasks may be completed in the future and built off the model described here. Task 1 specifically asked to incorporate the risk insights into the process for determining and prioritizing review of license amendment changes related to storage applications by outlining a resource allocation strategy and defining recommendations of for the depth and breadth of the LAR review. It was requested that the tool be similar in design to the SDP notebooks/worksheets and contain quantitative, qualitative, or semi-quantitative approaches to assessing the risk of the change. The final tool that was selected by INL to be developed was a flowchart and associated rationale document that allows the reviewer to quickly assess potential LAR changes and their associated risks as well as the rationale behind the risk categorization. This risk categorization will lead to specific actionable recommendations to expect from a change of that specific category. This allows for a more consistent review process as well as improving the overall efficiency of the review itself.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗

DOE OSTI2023

Prototyping the Light Detection of the DUNE Near Detector

The Deep Underground Neutrino Experiment (DUNE) is a long-baseline neutrino oscillation experiment with a 70kt liquid argon time projection chamber (LAr TPC) at the Far Detector complex at the Sanford Underground Research Facility (SURF) and a Near Detector (ND) complex planned for the Fermi National Accelerator Laboratory. The ND complex plans for three detector subsystems, including a modular LAr TPC comprised of 35 optically segregated modules. The modular detector design required the development a novel dielectric light readout, the ArCLight technology, which can be operated in a high voltage environment and has a large active surface. A demonstrator of four modular detectors, DUNE ND-LAr 2x2, will operate in 2023 in Fermilab's NuMI beam. After the construction of the modules was completed, they were successfully operated and commissioned in liquid argon using cosmic-ray muons at the University of Bern. This talk will discuss the designs of the light readout systems used in these modules with focus on the construction and commissioning of the ArCLights as well as the performance of the LRS during the tests at Bern.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2025

Analysis of scintillation light dependence on liquid Argon purity

Previous studies have investigated the correlation between impurity concentrations in Liquid Argon (LAr) and the temporal evolution of either the slow scintillation decay time or the light yield. These impurities typically consist of various molecular species. Electronegative contaminants directly affect electron drift and photon production, while other molecules, such as nitrogen (N_2),can influence LAr scintillation properties without necessarily affecting electron lifetime. Many current and future neutrino and dark-matter experiments use LAr detectors. This study aims to evaluate the measured electron lifetimes in relation to the timing characteristics of the scintillation light signal in the SBN ICARUS detector at Fermi National Accelerator Laboratory. The ICARUS experiment consists of two cryostats that have shown some discrepancies in the measured electron lifetime over the years. In particular, this study addresses the use of data collected under varying purity conditions in the two cryostats.

Saia, Clara [Catania Astrophys. Observ.]↗

DOE OSTI2022

SAND - System for on-Axis Neutrino Detection - in the DUNE Near Detector Complex

The DUNE experiment aims to precisely measure the long baseline neutrino oscillation parameters. The DUNE Far Detector consists of four liquid argon time-projection chambers (total LAr mass of 17 kton for each cryostat), that will be installed at the Sanford Underground Research Facility (SURF) in South Dakota, 1300 km from the proton beam target. The Near Detector complex, located at Fermilab, is fundamental for limiting the systematic uncertainties, due to the neutrino/antineutrino flux and to the cross-section. It comprises three complementary detectors: ND-Lar, ND-Gar and SAND (System for on-Axis Neutrino Detection). ND-Lar and ND-Gar can move off-axis, while SAND is the only detector permanently on-axis, whose primary goal is to monitor the beam and to measure the flux. In this talk, the SAND design and the expected performances will be described together with its role within the Near Detector complex for the DUNE physics program.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

DOE OSTI2026

Operation of a Modular 3D-Pixelated Liquid Argon Time-Projection Chamber in a Neutrino Beam

The 2x2 Demonstrator, a prototype for the Deep Underground Neutrino Experiment (DUNE) liquid argon (LAr) Near Detector, was exposed to the Neutrinos from the Main Injector (NuMI) neutrino beam at Fermi National Accelerator Laboratory (Fermilab). This detector is a prototype of a new modular design for a liquid argon time-projection chamber (LArTPC), comprising a two-by-two array of four modules, each further segmented into two optically isolated LArTPCs. The 2x2 Demonstrator features a number of pioneering technologies, including a low-profile resistive field shell to establish drift fields, native 3D ionization pixelated imaging, and a high-coverage dielectric light readout system. The 2.4-tonne active mass detector is flanked upstream and downstream by supplemental solid-scintillator tracking planes, repurposed from the MINERvA experiment, which track ionizing particles exiting the argon volume. The antineutrino beam data collected by the detector over a 4.5 day period in 2024 include over 30,000 neutrino interactions in the LAr active volume—the first neutrino interactions reported by a DUNE detector prototype. During its physics-quality run, the 2x2 Demonstrator operated at a nominal drift field of 500 V/cm and maintained good LAr purity, with a stable electron lifetime of approximately 1.25 ms. This paper describes the detector and supporting systems, summarizes the installation and commissioning, and presents the initial validation of collected NuMI beam and off-beam self-triggers. In addition, it highlights observed interactions in the detector volume, including candidate muon antineutrino events.

47 OTHER INSTRUMENTATION↗

NASA NTRS1994

Preprocessor Program For Use With PASCO

MACPASCO is interactive, graphical preprocessor program designed to make use of Panel Analysis and Sizing Code, PASCO, (COSMIC program numbers LAR-13004, LAR-13164, and LAR-14799) faster, simpler, and less error-prone. Is Macintosh-based preprocessor program that includes graphical user interface (GUI) program to simplify specification of panel geometry, making modeling and analysis of panel designs more efficient and reducing potential for user input errors. Written in Macintosh Programmers Workbench 3.0, MPW Pascal 3.0, and MacAPP 2.0.

Lucas, Stephen H.↗