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At least 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Long-Term Infrasound Sensor Calibration and Characterization

Previous testing has shown that infrasound sensors deployed in the field can exhibit notable deviations from their nominal, lab-based calibrations. These variations may be due to changes in environmental conditions, long-term sensor drift, or other unresolved features. In early 2018, we installed two identical infrasound elements with five infrasound sensors at each element (Chaparral M50A, Chaparral M64LN, CEA/Martec MB2005, CEA/Seismowave MB3a, and Hyperion IFS-5113A). These sensors were accepted or under consideration for use in the International Monitoring System network of the Comprehensive Nuclear-Test-Ban Treaty. Each element had all sensors connected to a single digitizer and port to the atmosphere. We also recorded instrument enclosure air temperature and humidity and external air temperature. Using the MB2005 as the reference, we examine the relative sensor response (both magnitude and phase) as a function of time and frequency and compare it with quarterly laboratory calibrations and environmental conditions. Here, we find that the magnitude response for all sensors exhibits some variability in both the lab and field, with the amplitude variations often >5%. The field-based variations are more severe and occur on both long-term (months) and short-term (hours) timescales. Short-term variability correlates with changes in environmental conditions and is considerable (up to 25%) for the Chaparral M50A and noticeable (∼5%) for the French Alternative Energies and Atomic Energy Commission (CEA) MB3a. Long-term magnitude variability for the Chaparral M50A was up to 50% and does not clearly correlate with environmental conditions. The other sensors show some long-term magnitude offsets, but they have relatively stable responses in the conditions we examined. The MB3a also displays some frequency-dependent magnitude variability and shows a minor dependence on temperature. Phase estimates are stable and near zero for all sensors tested. These results strongly suggest sensor response and variability due to environmental conditions should be considered in future infrasound data interpretation and sensor selection and development.

Fee, David↗
DOE OSTI2022

Standardization and First Lessons Learned of the Prototype HB650 Cryomodule for PIP-II at Fermilab

The prototype High Beta 650 MHz cryomodule (pHB650 CM) has been designed by an integrated design team, consisting of Fermilab (USA), CEA (France), STFC UKRI (UK), and RRCAT (India). The manufacturing and assembly of this prototype cryomodule is being done at Fermilab, whereas the production cryomodules will be manufactured and assembled by STFC-UKRI. As the first PIP-II cryomodule for which standardization was applied, the design, manufacturing and assembly of this cryomodule led to significant lessons being learnt and experiences gathered. These were incorporated into the design of the pre-production Single Spoke Resonator Type 2 cryomodule (ppSSR2 CM) and the pre-production Low Beta 650 MHz cryomodule (ppLB650 CM). This paper presents the pHB650 CM lessons learned and experiences gathered from the design to the lower coldmass assembly and how this cryomodule has a positive impact on all the next Proton Improvement Plan-II (PIP-II) cryomodules due to the standardization set up among SSR and 650 cryomodules.

43 PARTICLE ACCELERATORS↗
DOE OSTI2022

Design of the PIP-II 650 MHz Low Beta Cryomodule

The Proton Improvement Plan II (PIP-II) that will be installed at Fermilab is the first U.S. accelerator project that will have significant contributions from international partners. CEA joined the international collaboration in 2018, and is responsible of the 650 MHz low-beta section made of 9 cryomodules, with the design of the cryostat (i.e the cryomodule without the cavities, the power couplers and the frequency tuning systems) and the manufacturing of its components, the assembly and tests of the pre-production cryomodule and the 9 series ones. This paper will present the design of the 650 MHz low-beta cryomodule.

43 PARTICLE ACCELERATORS↗
DOE OSTI2022

Design of the 650 MHz High Beta Prototype Cryomodule for PIP-II at Fermilab

The Proton Improvement Plan II (PIP-II) is the first U.S. accelerator project that will have significant contributions from international partners. The prototype High Beta 650 MHz cryomodule (pHB650 CM) is designed by an integrated design team, consisting of Fermilab (USA), CEA (France), UKRI-STFC (UK), and RRCAT (India). The manufacturing & assembly of this prototype cryomodule will be done at Fermilab, whereas the production cryomodules will be manufactured and/or assembled by UKRI-STFC, RRCAT, or Fermilab. Similar to the prototype Single Spoke Resonator 1 cryomodule (pSSR1 CM), this cryomodule is based on a strong-back at room temperature supporting the coldmass. The pSSR1 CM led to significant lessons being learnt on the design, procurement, and assembly processes. These lessons were incorporated into the design and processes for the pHB650 CM. Amongst many challenges faced, the main challenges of the pHB650 CM design were to make the cryomodule compatible to overseas transportation and to design components that can be procured in USA, Europe, and India.

43 PARTICLE ACCELERATORS↗
DOE OSTI2023

Final Design of the LB650 Cryomodule for the PIP-II Linear Accelerator

The Proton Improvement Plan II (PIP-II) that will be installed at Fermilab is the first U.S. accelerator project that will have significant contributions from international partners. CEA joined the international collaboration in 2018, and its scope covers the supply of the 650 MHz low-beta cryomodule section, with the design of the cryostat (i.e the cryomodule without the cavities, the power couplers and the frequency tuning systems) and the manufacturing of its components, the assembly and tests of the pre-production cryomodule and 9 production modules. An important milestone was reached in April 2023 with the Final Design Review. This paper presents the detailed design of the 650 MHz low-beta cryomodules.

43 PARTICLE ACCELERATORS↗
DOE OSTI2023

Test Shipment of the PIP-II 650 MHz Transport Frame Between FNAL to STFC-UKRI

The PIP-II Project will receive fully assembled cryomodules from CEA and STFC-UKRI as in-kind contributions. Damage to these cryomodules during transport is understood to be a significant risk to the project, so an extensive testing and validation program is in process to mitigate this risk. The centerpiece of this effort is the eventual shipment from FNAL to STFC-UKRI and back of a prototype HB650 cryomodule with cold testing before and after shipment to verify no functionality changes from shipment. Most recently, a test shipment to the UK and back using a cryomodule analog was completed using realistic logistics, handling, instrumentation, and planning. The process of executing this test shipment, lessons learned, and plan moving forward will be presented here.

43 PARTICLE ACCELERATORS↗
DOE OSTI2020

Patchy snapshots of nuclear chain reactions

Stochastic fluctuations of the neutron population within a nuclear reactor are typically prevented by operating the core at a sufficiently high power. This regime, where the evolution of the neutron density is essentially deterministic, is key for automatic protection and safety systems to safely detect unwanted power excursions during an accident, and to rapidly initiate a reactor trip procedure in case it is needed. Recent works, supported by numerical simulations, have however reported that, for large reactors, the branching nature of the fission reactions might induce strongly non-Poissonian patterns in the neutron spatial distribution, and that stochastic fluctuations might still persist at reactor powers close to operating conditions (startup phase). An international program conducted by LANL, IRSN and CEA was therefore setup to experimentally detect and characterize such fluctuations and correlations. An experiment took place in 2017 at the Reactor Critical Facility (RCF) of the Rensselaer Polytechnic Institute (USA). In this paper we will report the main findings of this experimental program, supported by stochastic models and by the development of a dedicated high-fidelity Monte Carlo simulation code. We will in particular describe and explain the strong patchiness in neutron power distributions measured at the RCF, as well as a peculiar ‘blinking’ behavior of the core, and discuss the consequences of these findings on nuclear safety.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2021

NNSA/CEA Workflow Workshop Report 2021

Researchers from three NNSA labs plus CEA recently met for a half-day workshop on scientific and engineering workflows in March of 2021. Tools, projects and use cases from each institution were described. A wide range of unique capabilities and requirements were represented. The workshop highlights the fact that the CEA/NNSA workflows space mirrors the broader open science workflows community, with multiple technologies under development in a number of science domains and under a number of funding streams, with differing capabilities and focuses. Despite the number of tools, presentations and discussions have shown that these tools cover specific mission spaces at the four labs, each with distinctive capabilities that do not completely overlap with each other. We believe there is a strong interest in the short term for sharing lessons learned and collaborating on benchmarks and site evaluation of projects. This report, prepared by the NNSA/CEA Workflows Working Group, briefly summarizes the presentations in the areas of domain specific workflows, end user environments, data management, job and resource management, and infrastructure, and then identifies six broad areas for potential collaboration. A key finding is that users could benefit from greater interoperability, compatibility, and composability of the workflow technologies under development and that point-to-point collaboration opportunities should be identified to explore these aspects.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2021

MicroResonators for Compacts Optical Sensors (μRCOS)

As the demand for continuous, in-situ surveillance of health of systems and environments rapidly increases, miniaturized sensors with fast responses are sought. Optical dielectric resonators supporting Whispering Gallery Modes (WGMs) have exceptional properties, like very high-power density, very narrow spectral linewidth, and extremely small mode volume. As the footprint of these sensors is drastically reduced, measurements of microvolumes samples with dramatic reduction in analysis time are possible, enabling large numbers of parallel analyses using microarrays. The high sensitivity and speed of WGM resonators combined with the ability to detect molecules in their native state have great future potential for basic and applied research such as reliable single molecule, trace-gas detection, environmental monitoring, chemical threat sensing, and biodefense Such appealing peculiarities motivated us developing WMG resonators (WGMRs) for Cavity Enhanced Absorption Spectroscopy (CEAS) for chem-bio detection. Specifically, we designed and batch-fabricated microspheres and fiber tapers for resonances excitation. We successfully detected gases (N 2 and CO 2 ) in customized environmental chambers, and bio-organisms (Inf. A and E. Coli) with integrated microfluidic systems. Background calibration and environmental isolation were always accounted for in proving the performances.

36 MATERIALS SCIENCE↗
DOE OSTI2021

MicroResonators for Compacts Optical Sensors (μRCOS)

As the demand for continuous, in-situ surveillance of health of systems and environments rapidly increases, miniaturized sensors with fast responses are sought. Optical dielectric resonators supporting Whispering Gallery Modes (WGMs) have exceptional properties, like very high-power density, very narrow spectral linewidth, and extremely small mode volume. As the footprint of these sensors is drastically reduced, measurements of microvolumes samples with dramatic reduction in analysis time are possible, enabling large numbers of parallel analyses using microarrays. The high sensitivity and speed of WGM resonators combined with the ability to detect molecules in their native state have great future potential for basic and applied research such as reliable single molecule, trace-gas detection, environmental monitoring, chemical threat sensing, and biodefense Such appealing peculiarities motivated us developing WMG resonators (WGMRs) for Cavity Enhanced Absorption Spectroscopy (CEAS) for chem-bio detection. Specifically, we designed and batch-fabricated microspheres and fiber tapers for resonances excitation. We successfully detected gases (N 2 and CO 2 ) in customized environmental chambers, and bio-organisms (Inf. A and E. Coli) with integrated microfluidic systems. Background calibration and environmental isolation were always accounted for in proving the performances.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Environmental Brand Guidelines

The Environmental Brand Guidelines have been prepared by the CEA-CAS Visual Design team for use primarily by IFPROG, but they apply to all LANL employees ordering signage for new and existing buildings. By adhering to this guidance, you will be a responsible steward of the “One Lab, one voice” mentality and successfully implement the Lab’s brand on all of your communications.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

Campaign Guidelines: Security Starts With You [Slides]

The Security Starts With You Campaign Guidelines have been prepared by the CEA-CAS Visual Design team for use primarily by DSOs, FODs, and/or any LANL employee who wishes to extend the messaging to new and existing buildings. By adhering to this guidance, you will be a responsible steward of the “One Lab, one voice” mentality and successfully implement the Lab’s brand and security messaging on all of your communications.

96 KNOWLEDGE MANAGEMENT AND PRESERVATION↗
DOE OSTI2022

2022 MB3a Infrasound Sensor Type Approval Evaluation

Sandia National Laboratories has tested and evaluated an updated version of the MB3a infrasound sensor, designed by CEA and manufactured by SeismoWave. The purpose of this infrasound sensor evaluation is to measure the performance characteristics in such areas as power consumption, sensitivity, full scale, self-noise, dynamic range, response, passband, sensitivity variation due to changes in barometric pressure and temperature, and sensitivity to acceleration. The MB3a infrasound sensors are being evaluated for use in the International Monitoring System (IMS) of the Preparatory Commission to the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO).

47 OTHER INSTRUMENTATION↗
DOE OSTI2022

Print or order a LANSCE 50th anniversary poster [Poster]

To mark the anniversary of LANSCE and its five decades of cutting-edge science, the National Security Research Center’s graphic designer Gabriella Smith (from CEA-CAS) illustrated a commemorative poster now available for display. The LANSCE (the Los Alamos Neutron Science Center) facility houses one of the nation’s most powerful linear accelerators, which are used to improve safety and security as well as advance technology in stockpile sustainment, modern materials and manufacturing, and threat mitigation, among other areas. Now-deceased Lab scientist Louis Rosen, who is featured prominently on the poster, first proposed creating this major experimental science facility, said NSRC Archivist-Historian Madeline Whitacre (WRS-NSRCMS)

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2022

Evaluated 238 U(n,f) Average Prompt Fission Neutron Multiplicities Including the CGMF Model

This report documents an evaluation of the average prompt fission neutron multiplicity, $\overline{v}_p$, of 238 U from 800 keV to MeV. This evaluation had to be re-done from “scratch” as the input to previous $\overline{v}_p$ evaluations, specifically ENDF/B-VIII.0, was not found. That means that all available experimental data were re-analyzed and uncertainties were re-estimated. The new evaluated 238 U $\overline{v}_p$ based on only experimental data differs distinctly from ENDF/B-VIII.0 $\overline{v}_p$ from 2 to 4.5 MeV, and from 6 to 7 MeV, and is otherwise similar. The difference from 2 to 4.5 MeV stems from the fact that ENDF/B-VIII.0 was tweaked in this energy range to data of Frehaut, while two other, equally trustworthy, data sets would indicate an evaluated 238 U $\overline{v}_p$ that is up to 2% higher. Also, second chance fission in ENDF/B-VIII.0 was smoothed over from 6–7 MeV. Another major difference to ENDF/B-VIII.0 is that one of the evaluations presented here includes model information from the Hauser-Feshbach fission fragment decay code CGMF, while ENDF/B-VIII.0 is based purely on experimental data. CGMF links several fission quantities with each other; $\overline{v}_p$ is predicted by assumptions made on, e.g., pre-neutron emission yields as a function of mass, the total kinetic energy, or spin and parity of fission fragments. This allows to validate the new 238 U $\overline{v}_p$ by using CGMF parameters obtained from fitting to experimental 238 U $\overline{v}_p$ to predict yields as a function of mass, the average total kinetic energy, or the mean energy of the prompt fission neutron spectrum. These model-predicted values can then be compared to experimental and evaluated data. The model-predicted fission-observable values using evaluated parameters obtained here are reasonably close to experimental data for some observables, but are farther away from experimental data related to TKE observables. In addition to that, the evaluated 238 U(n,f) $\overline{v}_p$ shows similar deviations from ENDF/B-VIII.0 as for the evaluation with only experimental data. This difference is expected to lead to changes in simulated effective neutron multiplication factor, $k_{eff}$ of ICSBEP critical assemblies that are sensitive to 238 U in the fast range (BigTen, Flattop, Flattop-Pu). These changes in $k_{eff}$ need to be counter-balanced. Chi-Nu PFNS experimental data are expected to be released in the next few months that might lead to the needed changes in the PFNS. Until then, we hold off in benchmarking the new 238 U(n,f) $\overline{v}_p$ as well as submitting it to ENDF/B-VIII.1. Also, new high-precision 238 U $\overline{v}_p$ are expected to be measured by the CEA in the next two years that will shed further light on question on 238 U $\overline{v}_p$ from 2–4.5 and 6–7 MeV.

238U↗
DOE OSTI2023

Poster commemorates the Laboratory’s 80th anniversary

To celebrate the 80th anniversary of the Laboratory, award-winning artist and graphic designer Paul Ziomek (CEA-MP) created an original commemorative poster for Lab staff. The two-sided poster includes a montage of iconic images from the Lab’s collections in the National Security Research Center. The front showcases historic photographs of the secret laboratory and personnel from 1943 and then today’s National Security Sciences Building headquarters building. The back side includes explanations of the Lab’s earliest scientific achievements and Manhattan Project leader General Leslie Groves and Lab Director J. Robert Oppenheimer.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2022

Modeling and Simulation of Austenitic Welds and Coarse-grained Specimens: Part II

The Pacific Northwest National Laboratory (PNNL) is conducting confirmatory research for the U.S. Nuclear Regulatory Commission (NRC) to evaluate commercially available nondestructive examination (NDE) modeling and simulation software used in the nuclear industry. Simulation results from ultrasonic testing (UT) models can inform the design and qualification of inspection techniques and help interpret inspection results. CIVA is a modeling and simulation package developed by the French Alternative Energies and Atomic Energy Commission (CEA). CIVA was selected for this study because it is readily available and has been used for NDE in the US commercial nuclear power industry. This report is focused on completing the efforts initiated in the previous PNNL report to evaluate UT modeling and simulation performance, reliability, and accuracy in relation to common inservice inspection (ISI) scenarios in nuclear power plants (NPP). This work will be used to provide guidance when establishing methods to perform and evaluate simulations for more standardized model implementation, simulation analysis, and interpretation of results.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗