Results for “radiation test facilities” — Page 13

NASA NTRS1994

Line Profile Measurements of Atomic Oxygen at 1300 A with a VUV Raman Shifter

We are currently developing an atomic oxygen diagnostic to study the degree of oxygen dissociation in ground-based facilities. The absorption of the (sub 3)P - (sup 3)S(sup 0) resonance triplet in the vacuum ultraviolet is a direct measure of the ground state number density of atomic oxygen. Although the integrated line strength is well known for these transitions, the line profile is not. We report the results of a series of experiments in which the line profile is measured in shock-heated oxygen. An ArF excimer laser and a hydrogen Raman shifter generate tunable VUV radiation at the resonance wavelength. The test gas is dissociated oxygen, generated in the Electric Arc Shock Tube (EAST) Facility at NASA-Ames Research Center. By measuring the absorption of known concentrations of atomic oxygen, we are able to study the absorption line profile. The results will serve as a calibration to apply this diagnostic in other flowfields.

Sharma, Surendra P.↗

DOE OSTI2020

Radiation Testing for Nuclear Inspection Systems (Final CRADA Report)

Higher-radiation hardened video cameras are needed in the operation and remote handling of equipment in nuclear reactor inspection and refueling applications. Vega Wave Systems has developed a radiation-hardened vision system for Nuclear Energy applications. The high-radiation hardness testing of this vision system was conducted using the Argonne Low-Energy Accelerator Facility (LEAF).

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

DOE OSTI2023

Using optimal estimation to retrieve winds from velocity-azimuth display (VAD) scans by a Doppler lidar

Abstract. Low-powered commercially available coherent Doppler lidar (CDL) wind profilers provide continuous measurement of vertical profiles of wind in the lower troposphere, usually close to or up to the top of the planetary boundary layer. The vertical extent of these wind profiles is limited by the availability of scatterers and thus varies substantially throughout the day and from one day to the next. This makes it challenging to develop continuous products that rely on CDL-observed wind profiles. In order to overcome this problem, we have developed a new method for wind profile retrievals from CDL that combines the traditional velocity-azimuth display (VAD) technique with optimal estimation (OE) to provide continuous wind profiles up to 3 km. The new method exploits the level-to-level covariance present in the wind profile to fill in the gaps where the signal-to-noise ratio of the CDL return is too low to provide reliable results using the traditional VAD method. Another advantage of the new method is that it provides the full error covariance matrix of the solution and profiles of information content, which more easily facilitates the assimilation of the observed wind profiles into numerical weather prediction models. This method was tested using yearlong CDL measurements at the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) Central Facility in 2019. Comparison with the ARM operational CDL wind profile product and collocated radiosonde wind measurements shows excellent agreement (R2>0.99) with no degradation in results where the traditional VAD provided a valid solution. In the region where traditional VAD does not provide results, the OE wind speed and wind vector have uncertainties of 3.44 and 4.33 m s−1, respectively. As a result, the new method provides additional information over the standard technique and increases the effective range of existing CDL systems without the need for additional hardware.

54 ENVIRONMENTAL SCIENCES↗

NASA NTRS1969

Ablation in a radiative environment

Radiative heating rates and gas environments effects on ablative material performance from tests at arc image facility

Baker, E. J., Jr.↗

NASA NTRS1977

Photovoltaic system test facility electromagnetic interference measurements

Field strength measurements on a single row of panels indicates that the operational mode of the array as configured presents no radiated EMI problems. Only one relatively significant frequency band near 200 kHz showed any degree of intensity (9 muV/m including a background level of 5 muV/m). The level was measured very near the array (at 20 ft distance) while Federal Communications Commission (FCC) regulations limit spurious emissions to 15 muV/m at 1,000 ft. No field strength readings could be obtained even at 35 ft distant.

Johnson, J. A.↗

NASA NTRS2002

Test and Analysis Capabilities of the Space Environment Effects Team at Marshall Space Flight Center

Marshall Space Flight Center has developed world-class space environmental effects testing facilities to simulate the space environment. The combined environmental effects test system exposes temperature-controlled samples to simultaneous protons, high- and low-energy electrons, vacuum ultraviolet (VUV) radiation, and near-ultraviolet (NUV) radiation. Separate chambers for studying the effects of NUV and VUV at elevated temperatures are also available. The Atomic Oxygen Beam Facility exposes samples to atomic oxygen of 5 eV energy to simulate low-Earth orbit (LEO). The LEO space plasma simulators are used to study current collection to biased spacecraft surfaces, arcing from insulators and electrical conductivity of materials. Plasma propulsion techniques are analyzed using the Marshall magnetic mirror system. The micro light gas gun simulates micrometeoroid and space debris impacts. Candidate materials and hardware for spacecraft can be evaluated for durability in the space environment with a variety of analytical techniques. Mass, solar absorptance, infrared emittance, transmission, reflectance, bidirectional reflectance distribution function, and surface morphology characterization can be performed. The data from the space environmental effects testing facilities, combined with analytical results from flight experiments, enable the Environmental Effects Group to determine optimum materials for use on spacecraft.

Finckenor, M. M.↗

NASA NTRS2006

The Hyper-X Antenna Radiation Pattern Tests and Radio Frequency System Redesign

Testing was performed to determine the antenna radiation pattern measurements of the Hyper-X, X-43 ship 2 aircraft. One test was conducted at the Air Force Flight Test Center (AFFTC) Benefield Anechoic Facility (BAF) on January 24-January 27, 2000. A second test was done at MicroCraft in Tullahoma Tennessee by the Naval Air Weapons Center (NAWC) China Lake, California on September 8, 2001. The overall test objective was to gather qualitative antenna radiation pattern data from installed antennas on the HXRV. This objective was accomplished by collecting antenna radiation patterns at selected elevations of the HXRV. The test data was used to identify areas of RF coverage and assist in positioning the P-3 aircraft for best RF reception. The antenna pattern data presented nulls and possible low RF reception areas around the aircraft. This led to a redesign of the RF system. The redesigned system provided redundancy in case a telemetry transmitter should fail. The redesign provided more complete RF coverage within the antenna's capabilities. A second look at the flight path and necessary data collection led to a change in the beacon transponder system.

Hodge, Mark W.↗

NASA NTRS2017

Results of Simulated Galactic Cosmic Radiation (GCR) and Solar Particle Events (SPE) on Spectra Restraint Fabric

Spectra or similar Ultra-high-molecular-weight polyethylene (UHMWPE) fabric is the likely choice for future structural space suit restraint materials due to its high strength-to-weight ratio, abrasion resistance, and dimensional stability. During long duration space missions, space suits will be subjected to significant amounts of high-energy radiation from several different sources. To insure that pressure garment designs properly account for effects of radiation, it is important to characterize the mechanical changes to structural materials after they have been irradiated. White Sands Test Facility (WSFTF) collaborated with the Crew and Thermal Systems Division at the Johnson Space Center (JSC) to irradiate and test various space suit materials by examining their tensile properties through blunt probe puncture testing and single fiber tensile testing after the materials had been dosed at various levels of simulated GCR and SPE Iron and Proton beams at Brookhaven National Laboratories. The dosages were chosen based on a simulation developed by the Structural Engineering Division at JSC for the expected radiation dosages seen by space suit softgoods seen on a Mars reference mission. Spectra fabric tested in the effort saw equivalent dosages at 2x, 10x, and 20x the predicted dose as well as a simulated 50 year exposure to examine the range of effects on the material and examine whether any degradation due to GCR would be present if the suit softgoods were stored in deep space for a long period of time. This paper presents the results of this work and outlines the impact on space suit pressure garment design for long duration deep space missions.

Peters, Benjamin↗

NASA NTRSDate not supplied

Impact of Space Radiation on Plants: from Arabidopsis thaliana to Crops

One of the major concerns for long-term exploration missions beyond the Earth’s magnetosphere is radiation risk, primarily from solar particle events (SPE) and galactic cosmic rays (GCR). With the goal of manned Mars exploration, the production of fresh food during long-duration space missions provides critical nutritional supplementation and may also benefit astronauts’ behavioral health. However, the effects of space radiation on plants and plant propagules have not been sufficiently investigated and characterized. In this study, we evaluated the effect of simulated GCR (using dry seeds) or SPE (using hydrated seeds) on seeds of Arabidopsis, Mizuna mustard, ‘Outredgeous’ red romaine lettuce, and ‘Red Robin’ dwarf tomato. Seeds were exposed to various doses of simulated space radiation scenarios, either acutely or at a low dose rate (LDR), using the NASA Space Radiation Laboratory (NSRL) facility at Brookhaven National Lab (BNL). Exposure to simulated GCR or SPE at the levels tested had no significant impact on the germination rate in Arabidopsis and crop seeds; however, GCR reduced the viability of lettuce and tomato seeds. Overall, the morphological changes of the seedlings cultured from irradiated seeds were dose- and ion quality- dependent, with heavier ions causing more severe damage. These changes ranged from cotyledon deformation, shortened root length, smaller seedling size, and other signs of stress, depending on the seed types. Both 40 and 80 cGy (LDR) exposures of GCR or SPE significantly affected tomato early seedling development, delayed tomato fruiting, and reduced the total yield of tomato. Altered nutritional values were also found in edible biomass, especially for the GCR 80 cGy (LDR) groups. For both GCR and SPE, 40 cGy showed some effects, but to a much lesser extent compared with 80 cGy, which can be considered as the “maximum permissible exposure” for the seed types we evaluated in this study. The impact of space radiation on seeds potentially affects the ability of plants to adapt to other environmental stresses (e.g. microgravity, water stress, and hardware constraints) as well as susceptibility to plant diseases, which need to be furtherly investigated. This research is funded by NASA’s Human Research Program.

J T Richards↗

NASA NTRSDate not supplied

Impact of Space Radiation on Plant Seeds: from Arabidopsis thaliana to Crops

One of the major concerns for long-term exploration missions beyond the Earth’s magnetosphere is radiation risk, primarily from solar particle events (SPE) and galactic cosmic rays (GCR). With the goal of manned Mars exploration, the production of fresh food during long-duration space missions provides critical nutritional supplementation and may also benefit astronauts’ behavioral health. However, the effects of space radiation on plants and plant propagules have not been sufficiently investigated and characterized. In this study, we evaluated the effect of simulated GCR (using dry seeds) or SPE (using hydrated seeds) on seeds of Arabidopsis, Mizuna mustard, ‘Outredgeous’ red romaine lettuce, and ‘Red Robin’ dwarf tomato. Seeds were exposed to various doses of simulated space radiation scenarios, either acutely or at a low dose rate (LDR), using the NASA Space Radiation Laboratory (NSRL) facility at Brookhaven National Lab (BNL). Exposure to simulated GCR or SPE at the levels tested had no significant impact on the germination rate in Arabidopsis and crop seeds; however, GCR reduced the viability of lettuce and tomato seeds. Overall, the morphological changes of the seedlings cultured from irradiated seeds were dose- and ion quality- dependent, with heavier ions causing more severe damage. These changes ranged from cotyledon deformation, shortened root length, smaller seedling size, and other signs of stress, depending on the seed types. Both 40 and 80 cGy (LDR) exposures of GCR or SPE significantly affected tomato early seedling development, delayed tomato fruiting, and reduced the total yield of tomato. Altered nutritional values were also found in edible biomass, especially for the GCR 80 cGy (LDR) groups. For both GCR and SPE, 40 cGy showed some effects, but to a much lesser extent compared with 80 cGy, which can be considered as the “maximum permissible exposure” for the seed types we evaluated in this study. The impact of space radiation on seeds potentially affects the ability of plants to adapt to other environmental stresses (e.g. microgravity, water stress, and hardware constraints) as well as susceptibility to plant diseases, which need to be furtherly investigated. This research is funded by NASA’s Human Research Program.

J T Richards↗

NASA NTRSDate not supplied

Impact of Space Radiation on Plant Seeds: from Arabidopsis thaliana to Crops

One of the major concerns for long-term exploration missions beyond the Earth’s magnetosphere is radiation risk, primarily from solar particle events (SPE) and galactic cosmic rays (GCR). With the goal of manned Mars exploration, the production of fresh food during long-duration space missions provides critical nutritional supplementation and may also benefit astronauts’ behavioral health. However, the effects of space radiation on plants and plant propagules have not been sufficiently investigated and characterized. This is the final report of our project to summarize the findings of the effect of space radiation exposure on plant seeds from morphometrics, nutritional values, to molecular machenisms. In this study, we evaluated the effect of simulated GCR (using dry seeds) or SPE (using hydrated seeds) on seeds of Arabidopsis, Mizuna mustard, ‘Outredgeous’ red romaine lettuce, and ‘Red Robin’ dwarf tomato. Seeds were exposed to various doses of simulated space radiation scenarios, either acutely or at a low dose rate (LDR), using the NASA Space Radiation Laboratory (NSRL) facility at Brookhaven National Lab (BNL). Exposure to simulated GCR or SPE at the levels tested had no significant impact on the germination rate in Arabidopsis and crop seeds; however, GCR reduced the viability of lettuce and tomato seeds. Overall, the morphological changes of the seedlings cultured from irradiated seeds were dose- and ion quality- dependent, with heavier ions causing more severe damage. These changes ranged from cotyledon deformation, shortened root length, smaller seedling size, and other signs of stress, depending on the seed types. Both 40 and 80 cGy (LDR) exposures of GCR or SPE significantly affected tomato early seedling development, delayed tomato fruiting, and reduced the total yield of tomato. Altered nutritional values were also found in edible biomass, especially for the GCR 80 cGy (LDR) groups. Underlying mechanisms were furtherly evaluated using transcriptomic analysis. For both GCR and SPE, 40 cGy showed some effects, but to a much lesser extent compared with 80 cGy, which can be considered as the “maximum permissible exposure” for the seed types we evaluated in this study. The impact of space radiation on seeds potentially affects the ability of plants to adapt to other environmental stresses (e.g. microgravity, water stress, and hardware constraints) as well as susceptibility to plant diseases, which need to be furtherly investigated. This research is funded by NASA’s Human Research Program.

J T Richards↗

NASA NTRSDate not supplied

Impact of Space Radiation on Plant Seeds: from Arabidopsis thaliana to Crops

One of the major concerns for long-term exploration missions beyond the Earth’s magnetosphere is radiation risk, primarily from solar particle events (SPE) and galactic cosmic rays (GCR). With the goal of manned Mars exploration, the production of fresh food during long-duration space missions provides critical nutritional supplementation and may also benefit astronauts’ behavioral health. However, the effects of space radiation on plants and plant propagules have not been sufficiently investigated and characterized. This is the final report of our project to summarize the findings of the effect of space radiation exposure on plant seeds from morphometrics, nutritiaonal values, to molecular machenisms. In this study, we evaluated the effect of simulated GCR (using dry seeds) or SPE (using hydrated seeds) on seeds of Arabidopsis, Mizuna mustard, ‘Outredgeous’ red romaine lettuce, and ‘Red Robin’ dwarf tomato. Seeds were exposed to various doses of simulated space radiation scenarios, either acutely or at a low dose rate (LDR), using the NASA Space Radiation Laboratory (NSRL) facility at Brookhaven National Lab (BNL). Exposure to simulated GCR or SPE at the levels tested had no significant impact on the germination rate in Arabidopsis and crop seeds; however, GCR reduced the viability of lettuce and tomato seeds. Overall, the morphological changes of the seedlings cultured from irradiated seeds were dose- and ion quality- dependent, with heavier ions causing more severe damage. These changes ranged from cotyledon deformation, shortened root length, smaller seedling size, and other signs of stress, depending on the seed types. Both 40 and 80 cGy (LDR) exposures of GCR or SPE significantly affected tomato early seedling development, delayed tomato fruiting, and reduced the total yield of tomato. Altered nutritional values were also found in edible biomass, especially for the GCR 80 cGy (LDR) groups. Underlying mechanisms were furtherly evaluated using transcriptomic analysis. For both GCR and SPE, 40 cGy showed some effects, but to a much lesser extent compared with 80 cGy, which can be considered as the “maximum permissible exposure” for the seed types we evaluated in this study. The impact of space radiation on seeds potentially affects the ability of plants to adapt to other environmental stresses (e.g. microgravity, water stress, and hardware constraints) as well as susceptibility to plant diseases, which need to be furtherly investigated. This research is funded by NASA’s Human Research Program.

J.T. Richards↗

NASA NTRS1997

Investigation of Teflon FEP Embrittlement on Spacecraft in Low Earth Orbit

Teflon(registered trademark) FEP (fluorinated ethylene-propylene) is commonly used on exterior spacecraft surfaces in the low Earth orbit (LEO) environment for thermal control. Silverized or aluminized FEP is used for the outer layer of thermal control blankets because of its low solar absorptance and high thermal emittance. FEP is also preferred over other spacecraft polymers because of its relatively high resistance to atomic oxygen erosion. Because of its low atomic oxygen erosion yield, FEP has not been protected in the space environment. Recent, long term space exposures such as on the Long Duration Exposure Facility (LDEF, 5.8 years in space), and the Hubble Space Telescope (HST, after 3.6 years in space) have provided evidence of LEO environmental degradation of FEP. These exposures provide unique opportunities for studying environmental degradation because of the long durations and the different conditions (such as differences in altitude) of the exposures. Samples of FEP from LDEF and from HST (retrieved during its first servicing mission) have been evaluated for solar induced embrittlement and for synergistic effects of solar degradation and atomic oxygen. Micro-indenter results indicate that the surface hardness increased as the ratio of atomic oxygen fluence to solar fluence decreased for the LDEF samples. FEP multilayer insulation (MLI) retrieved from HST provided evidence of severe embrittlement on solar facing surfaces. Micro-indenter measurements indicated higher surface hardness values for these samples than LDEF samples, but the solar exposures were higher. Cracks induced during bend testing were significantly deeper for the HST samples with the highest solar exposure than for LDEF samples with similar atomic oxygen fluence to solar fluence ratios. If solar fluences are compared, the LDEF samples appear as damaged as HST samples, except that HST had deeper induced cracks. The results illustrate difficulties in comparing LEO exposed materials from different missions. Because the HST FEP appears more damaged than LDEF FEP based on depth of embrittlement, other causes for FEP embrittlement in addition to atomic oxygen and ultraviolet (UV) radiation, such as thermal effects and the possible role of soft x-ray radiation, need to be considered. FEP that was exposed to soft x-rays in a ground test facility, showed embrittlement similar to that witnessed in LEO, which indicates that the observed differences between LDEF and HST FEP might be attributed to the different soft x-ray fluences during these two missions.

deGroh, Kim K.↗

DOE OSTI2020

Impact of Grain Size on Performance Degradation of TREAT LEU

We argue that radiation damage induced degradation of thermal conductivity does not set a lower limit on fuel grain sizes for the low enriched uranium fuel design of the Transient Reactor Test Facility (TREAT). Earlier work reports that smaller grains cause a larger degradation of thermal conductivity than larger grains constraining the smallest feasible size of fuel grains. This work assesses TREAT’s transient performance in the presence of radiation damage. The difference between the two studies is in treating damaged and fresh graphite as serial (this work) or parallel (previous) heat resistors. We use a multiphysics model of TREAT fuel grains to compute the reduction in transient capability measured by the total deposited energy as a function of irradiation dose. We find that radiation damage has a negligible effect on energy deposition.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2020

National Weather Service Radiosonde Evaluation Field Campaign Report

The purpose of the campaign was to perform a full evaluation of participating vendor’s radiosondes to qualify for potential use in the National Weather Service (NWS) upper air field operations. The NWS has specific requirements that vendors systems were evaluated against to determine if the vendor’s radiosonde performs within specifications. For this evaluation, the NWS was pursuing commercial off-the-shelf (COTS) ground/tracking systems in the 403 MHz frequency band over the previously used Telemetry Receiving System (TRS) and house-built software using the 1680 MHz frequency. The U.S. Department of Energy Atmospheric Radiation Measurement (ARM) user facility’s Southern Great Plains (SGP) observatory served as the warm and dry test region. The radiosondes were assessed for precision of the radiosonde (unit under test versus itself) and accuracy of the radiosonde’s humidity measurements (unit under test versus a cryogenic frostpoint hygrometer [CFH]).

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2020

Description of the Three-Dimensional Large-Scale Forcing Data from the 3D Constrained Variational Analysis (VARANAL3D)

This technical report introduces a Three-Dimensional Constrained Variational Analysis (3DCVA) (Tang and Zhang 2015) and its product of three-dimensional large-scale forcing data to drive single-column models (SCM), cloud-resolving models (CRM), and large-eddy simulation (LES) models, and to evaluate model results. The 3DCVA algorithm is an extension of the original 1D constrained variational analysis (1DCVA) (Zhang and Lin 1997, Zhang et al. 2001). The three-dimensional structure of the forcing data allows studies of spatial variation of the large-scale forcing fields and tests of physical parameterizations across scales. In the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) user facility, the 3D forcing data are assigned the datastream name varanal3d. In this technical report, 3DCVA will be used to refer to the algorithm, while VARANAL3D will be used to refer to the data product.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2020

Description of the Three-Dimensional Large-Scale Forcing Data from the 3D Constrained Variational Analysis (VARANAL3D)

This technical report introduces a Three-Dimensional Constrained Variational Analysis (3DCVA) (Tang and Zhang 2015) and its product of three-dimensional large-scale forcing data to drive single-column models (SCM), cloud-resolving models (CRM), and large-eddy simulation (LES) models, and to evaluate model results. The 3DCVA algorithm is an extension of the original 1D constrained variational analysis (1DCVA) (Zhang and Lin 1997, Zhang et al. 2001). The three-dimensional structure of the forcing data allows studies of spatial variation of the large-scale forcing fields and tests of physical parameterizations across scales. In the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) user facility, the 3D forcing data are assigned the datastream name varanal3d. In this technical report, 3DCVA will be used to refer to the algorithm, while VARANAL3D will be used to refer to the data product.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2023

Coast-Urban-Rural Atmospheric Gradient Experiment

Accurately representing the climate and weather variability within cities and providing well-tested representations of the impacts of urban systems on the atmospheric environment are challenges for current earth system models (ESMs). Field data for testing and developing these models are critical to addressing these limitations. The Atmospheric Radiation Measurement (ARM) user facility will support a field campaign aimed at understanding how different surface-atmosphere interactions around a city are influencing its climate. The Coast-Urban-Rural Atmospheric Gradient Experiment (CoURAGE) is expected to operate from December 2024 to November 2025 in and around Baltimore, Maryland. With its aging infrastructure, growing susceptibility to heat and flooding, and ongoing issues with air and water pollution, Baltimore is characteristic of many large industrial cities in the Eastern United States. ARM, a U.S. Department of Energy (DOE) Office of Science user facility, plans to deploy one of its three mobile observatories at Morgan State University’s Clifton Park site in downtown Baltimore. Ancillary ARM sites are also planned for rural Maryland, northwest of the city; and to the southern end of Kent Island in Chesapeake Bay. Data from CoURAGE will complement measurements from the Baltimore Social-Environmental Collaborative (BSEC), one of four DOE Urban Integrated Field Laboratories that will operate in cities across the United States to study urban climate change.

54 ENVIRONMENTAL SCIENCES↗