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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 181 records · Page 10
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Texturizing Wind Turbine Towers to Reduce Bat Mortality

There is still a great need for the development of mitigation strategies that are economically viable and can be used alone or in combination with other options (e.g., operational minimization, acoustic deterrents) to ensure that bat fatalities are effectively reduced at wind facilities across the U.S. Our goal was to develop a wind turbine tower coating that 1) bats show little or no interest in approaching, 2) can be applied to currently deployed wind turbine towers and to towers as they are constructed, 3) is economically feasible to produce and apply, and 4) ultimately contributes to a reduction in bat mortality at utility-scale wind facilities. Wind turbine tower monopoles are large, smooth surfaces and numerous studies have reported bats making close investigative approaches at turbine tower surfaces that are suggestive of drinking and foraging behavior. We therefore hypothesized that such activity could be contributing to bat-wind turbine fatalities by increasing the amount of time that bats spend in or around the rotor-swept zone. We further hypothesized that a texturizing the tower might minimized bat activity at the towers and therefore reduce fatality risk. To explore this, we designed a series of experiments to characterize how bats interact with smooth and texture-treated surfaces in a controlled environment. We conducted 64 behavioral trials in a flight facility from 10 June to 25 September 2015 and an additional 76 behavioral trials from 9 June to 30 August 2016. The first set of trials showed that while bats did make contact with smooth surfaces, they did not make contact with textured surfaces. We ascertained that bat activity occurred at 0 to 1 m distances from surfaces, suggesting that the bats (used in this study) may need to be this close to a surface to accurately discern its texture. From the results were developed a texture coating. For the second set of trials, we tested the texture coating. Bats showed a >40% reduction in activity within 1 m of the textured surfaces in comparison to the smooth surfaces. Following these controlled experiments, we conducted field tests at Wolf Ridge Wind, LLC. We applied the texture coating to the midsection of turbine monopoles. The texture coating was manually applied to 2 turbine towers, although we noted during the application there was variation in texture coating between turbines. We considered that this variation could potentially impact bat behavior. We then conducted bat activity surveys at both texture-treated towers and 2 nearby control towers, over 55 nights from 24 June to 22 September, 2017. All species of bats known to be present at the site were detected in the acoustic recordings at these turbine towers. We found no significant differences in overall numbers of bats observed and levels of acoustic activity at the smooth and texture-treated towers. When we analyzed the experimental pairs separately, however, we found that a greater proportion of the close range bat activity within Pair 1 occurred at the texture-treated tower and that much of this activity could be attributed to foraging behavior. In contrast at turbine Pair 2, we observed no difference in the proportion of close range bat activity between the smooth and texture-treated tower, with no clear differences in behavior at the two tower types. When we examined acoustic bat activity at the tower pairs separately, we found species-specific differences in activity that differed between the smooth and texture-treated towers within the pairs. For example, hoary bat acoustic activity was significantly higher at the texture-treated tower in Pair 1, but significantly lower at the texture-treated tower in Pair 2. Given the observational nature of the field test, our limited sample size (2 turbine pairs), variation in the texture-coating between the 2 turbine pairs, and different patterns of bat activity observed at the 2 turbine pairs, inferences from this one field test are limited at best. In conclusion, the results from the flight facility experiments were promising (i.e., we observed a significant decrease in bat activity at smooth compared to texture-treated surfaces); however, due to coating installation and application challenges prior to our field test, we were unable to collect sufficient information to understand how these coatings affect bat activity at operational wind turbine towers. Although the results from the field test are inconclusive, the lessons learned will be informative for future research into turbine surface materials that can modify the surface of the turbine tower and therefore alter how bats perceive wind towers. Thus, the outcomes of this research project may have a significant impact on wind energy operators, wind developers, and OEMs by contributing to future impact mitigation strategies. In future research we will test new ideas to improve the development, application, and evaluation of this mitigation technique.

17 WIND ENERGY↗
DOE OSTI2020

Assessment of Near-Term Fuel Screening and Qualification Needs for Nuclear Thermal Propulsion Systems

Nuclear thermal propulsion (NTP) is an in-space propulsion technology capable of both high specific impulse (850–1000 s) and thrust (44–1112 kN), which can help reduce trip times for crewed missions beyond low Earth orbit. NTP technology has been demonstrated during historic programs. Over 20 ground test reactor experiments were performed, which demonstrated the prototypic reactor operations, during the Nuclear Engine for Rocket Vehicle Application (NERVA)/Rover program (1955–1972). Although historical programs have shown that NTP is a viable in-space propulsion technology, developing NTP in modern programs is contingent on the development and qualification of ultrahigh-temperature nuclear fuel technologies that can withstand engine operating conditions. In historical NTP development programs such as NERVA/Rover, prototypic reactor/engine schemes were ground tested to assess the overall system feasibility and to qualify the reactor fuel forms for eventual flight systems. Although this approach is effective to verify fuel performance under prototypic conditions, relying solely on full-scale NTP reactor tests as the pathway for verifying or qualifying fuel is inefficient and cost prohibitive today. Additionally, modern nuclear licensing requirements state that before test reactor approval, reactor components and fuel elements should be qualified via non-nuclear (out-of-pile) and nuclear (in-pile) testing under representative operating conditions. Using this methodology, fuel matures as production scale fabrication methods are established, and as produced fuel performance is demonstrated. Here, this paper provides an overview of historical approaches to NTP fuel performance maturation, including fuel screening and qualification needs, and provides insight for establishing an efficient testing paradigm that can be implemented to rapidly and affordably develop NTP fuel forms for eventual qualification.

42 ENGINEERING↗
DOE OSTI2024

Evaluation of an x-ray multilayer mirror for radiography at sub-1-keV photon energies

An x-ray multilayer mirror on a spherical substrate designed for near-normal incidence with a photon energy of ~738 eV (F He α ) was procured and tested. This device is intended to be used for in-flight radiography of the shell in inertial confinement fusion experiments with cryogenic targets on the OMEGA laser at the Laboratory for Laser Energetics. Experiments in self-emission on a small (~10 J) laser system showed that the reflectivity of the mirror is high enough to record an image at laser energies as low as 0.1 J. Furthermore, a second set of tests in backlighting geometry on a larger (kJ)-scale, short-pulse laser yielded usable radiographs with laser energies as low as 40 J with a spatial resolution of ~10 μm.

47 OTHER INSTRUMENTATION↗
DOE OSTI2018

Interpretation of Indications Generated by Small Welding Discontinuities in Ultrasonic Time of Flight Diffraction Technique

The article presents results of research on non-destructive ultrasonic time of flight diffraction technique TOFD and metallographic examinations of selected cross-sections of a MAG welded joint. The main objective was to compare the results of TOFD and metallographic examination at the locations where a large number of point-like indications, located on specific depths, have been detected on TOFD images and analyse the impact of this type of indication on results of a welded joint evaluation. Considered, that the indications have not exhibited separations between upper and lower diffraction signals, because of their small heights, measuring of height of indications in those cases was impossible. In all cases, the occurrence of discontinuities of 0.16–0.78 mm in height, in locations indicated by TOFD has been confirmed.

42 ENGINEERING↗
DOE OSTI2020

Impact of Vibrational Nonequilibrium on the Supersonic Mode in Hypersonic Boundary Layers

The supersonic mode in hypersonic boundary layers has recently been shown to achieve a larger peak growth rate than the traditional second mode in particular circumstances relevant to free flight. In this environment, high levels of aerodynamic heating are encountered such that incorporation of chemical and vibrational nonequilibrium effects can become critical. The impact of thermal nonequilibrium (TNE) on the supersonic mode in particular has not been thoroughly and systematically investigated. This work uses thermochemical nonequilibrium (TCNE) direct numerical simulation (DNS) and TCNE linear stability theory (LST) to obtain a more complete investigation of the supersonic mode using both nonequilibrium and frozen gas models. The simulation is Mach 5 flow over a 1-mm-nose-radius axisymmetric cone 1 m in length, representative of experimental conditions in ground test facilities. Both LST and DNS results indicate that TNE effects are destabilizing compared with frozen flow and can lead to an N-factor difference of approximately +1 at the end of the cone. LST results also indicate that TNE effects are stabilizing to the second and supersonic modes in comparison with thermal equilibrium. The supersonic mode appeared to be slightly more affected by TNE than the second mode. In conclusion, collectively, the findings in this work suggest that even in ground test facilities where TCNE effects are relatively small compared with free flight, incorporating nonequilibrium models in both the mean flow and stability solvers can have a practical effect on hypersonic boundary-layer transition prediction analyses.

42 ENGINEERING↗
DOE OSTI2025

Resolve instrument onboard XRISM: design, integration, and instrument test results

The Resolve instrument onboard the X-Ray Imaging and Spectroscopy Mission (XRISM) consists of an array of 6 × 6 silicon-thermistor microcalorimeters cooled down to 50 mK and a high-throughput X-ray mirror assembly (XMA) with a focal length of 5.6 m. XRISM is a recovery mission of ASTRO-H/Hitomi, and the Resolve instrument is a rebuild of the ASTRO-H Soft X-ray spectrometer (SXS) and the Soft X-ray Telescope (SXT) that achieved energy resolution of ∼ 5 eV FWHM on orbit, with several important changes based on lessons learned from ASTRO-H. The flight models of the Dewar and the electronics boxes were fabricated, and the instrument test and calibration were conducted in 2021. By tuning the cryocooler frequencies, energy resolution better than 4.9 eV FWHM at 6 keV was demonstrated for all 36 pixels and high-resolution grade events, as well as energy-scale accuracy better than 2 eV up to 30 keV. The immunity of the detectors to microvibration, electrical conduction, and radiation was evaluated. The instrument was delivered to the spacecraft system in April 2022. The XMA was tested and calibrated separately. Its angular resolution is 1.27′, and the effective area of the mirror itself is 570 cm 2 at 1 keV and 424 cm 2 at 6 keV. We report the design and the major changes from the ASTRO-H SXS, the integration, and the results of the instrument test.

X-ray↗
DOE OSTI2019

Skin remittance kinetics in the spectral range of 550 – 790 nm

An experimental method for remitted photon time-of-flight (PTOF) estimation in human skin in vivo is developed and tested. Remitted light signals are obtained using a picosecond broadband laser and a set of narrowband interference filters centred at 550, 600, 650, 700, 750 and 790 nm. Four different distances of 8, 12, 16 and 20 mm between the source and detector fibres are used. Measurements are performed at different wavelengths and distance combinations. Direct kinetic measurements make it possible to assess the mean photon path length in skin at various spectral regions. Results generally correspond to theoretical expectations; however, no clear dependence on wavelengths in the spectral range 650–790 nm is observed. This study shows a promising opportunity to use this kind of measurement system in the future research of PTOF in human skin. (paper)

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2013

Environmental Impacts of Wind Power Development on the Population Biology of Greater Prairie-Chickens

1. We investigated the impacts of wind power development on the demography, movements, and population genetics of Greater Prairie-Chickens (Tympanuchus cupido) at three sites in northcentral and eastern Kansas for a 7-year period. Only 1 of 3 sites was developed for wind power, the 201MW Meridan Way Wind Power Facility at the Smoky Hills site in northcentral Kansas. Our project report is based on population data for prairie chickens collected during a 2-year preconstruction period (2007-2008), a 3-year postconstruction period (2009-2011) and one final year of lek surveys (2012). Where relevant, we present preconstruction data from our field studies at reference sites in the northern Flint Hills (2007-2009) and southern Flint Hills (2006-2008). 2. We addressed seven potential impacts of wind power development on prairie chickens: lek attendance, mating behavior, use of breeding habitat, fecundity rates, natal dispersal, survival rates, and population numbers. Our analyses of pre- and postconstruction impacts are based on an analysis of covariance design where we modeled population performance as a function of treatment period, distance to eventual or actual site of the nearest wind turbine, and the interaction of these factors. Our demographic and movement data from the 6-year study period at the Smoky Hills site included 23 lek sites, 251 radio-marked females monitored for 287 bird-years, and 264 nesting attempts. Our genetic data were based on genotypes of 1,760 females, males and chicks that were screened with a set of 27 microsatellite markers that were optimized in the lab. 3. In our analyses of lek attendance, the annual probability of lek persistence during the preconstruction period was ~0.9. During the postconstruction period, distance to nearest turbine did not have a significant effect on the probability of lek persistence. However, the probability of lek persistence increased from 0.69 at 0 m to 0.89 at 30 km from turbines, and most abandoned lek sites were located <5 km from turbines. Probability of lek persistence was significantly related to habitat and number of males. Leks had a higher probability of persistence in grasslands than agricultural fields, and increased from ~0.2 for leks of 5 males, to >0.9 for leks of 10 or more males. Large leks in grasslands should be a higher priority for conservation. Overall, wind power development had a weak effect on the annual probability of lek persistence. 3. We used molecular methods to investigate the mating behavior of prairie chickens. The prevailing view for lek-mating grouse is that females mate once to fertilize the clutch and that conspecific nest parasitism is rare. We found evidence that females mate multiple times to fertilize the clutch (8-18% of broods, 4-38% of chicks) and will parasitize nests of other females during egg-laying (~17% of nests). Variable rates of parentage were highest in the fragmented landscapes at the Smoky Hills field site, and were lower at the Flint Hills field site. Comparisons of the pre- and postconstruction periods showed that wind energy development did not affect the mating behaviors of prairie chickens. 4. We examined use of breeding habitats by radio-marked females and conducted separate analyses for nest site selection, and movements of females not attending nests or broods. The landscape was a mix of native prairie and agricultural habitats, and nest site selection was not random because females preferred to nest in grasslands. Nests tended to be closer to turbines during the postconstruction period and there was no evidence of behavioral avoidance of turbines by females during nest site selection. Movements of females not attending nests or broods showed that females crossed the site of the wind power development at higher rates during the preconstruction period (20%) than the postconstruction period (11%), and that movements away from turbines were more frequent during the postconstruction period. Thus, wind power development appears to affect movements in breeding habitats but not nest site selection of female prairie chickens during the breeding season. 5. We tested the effects of wind power development on five components of female fecundity: timing of clutch initiation, clutch size of first nests and renests, nest survival, and hatchability of eggs. Average date of clutch initiation was 26 April, clutch size was 12.7 and 10.6 eggs for first nests and renests, probability of nest survival was low at 0.18, but egg hatchability was high at 0.79. Wind power development had no impact on reproductive effort or nesting success, and all five components of fecundity were not related to treatment period or distance to turbine. Nest survival was the main factor limiting reproductive output of female prairie chickens and most losses were due to predation. Daily nest survival was strongly related to vegetative cover at the nest. Changes to rangeland management practices that would double nesting cover from 2.5 to 5 dm would triple the probability of nest survival from 0.17 to 0.52. Grass and forb cover had weak positive effects on daily nest survival whereas shrub cover, proximity to woodlands, and recent rainfall had negative effects. Reproductive performance of prairie chickens is low in managed rangelands in northcentral Kansas and efforts to improve range conditions and reduce predator activity would aid recovery of prairie chicken populations. 6. We used molecular methods to investigate patterns of natal dispersal in prairie chickens. High rates of nest failure limited the number of young that we could sample. Direct detections of natal dispersal were limited because survival of newly hatched chicks to become adults were low and because we were unable to detect dispersal distances outside of our study area. Direct observations of natal movements were limited and were inadequate to make conclusions about the potential impacts of wind energy development on natal dispersal. Spatial correlograms of genetic distance among males at leks were a more sensitive measure of population structure, and indicated a weak effect of wind energy development on the spatial genetic structure of prairie chickens. 7. We tested the effects of wind power development on female survival with time-to-event models, and on residual body mass of males with analyses of covariance. Distance to turbine and the interaction of distance and treatment period had no effect on female survival. Contrary to predictions of negative impacts of wind power development, the probability of female was lowest during the preconstruction period (0.274) and increased significantly during the postconstruction period (0.543). Inspection of hazard functions indicated that the difference in annual survival could be attributed to a higher risk of mortality during the lekking season in the preconstruction period. We suggest that wind power development may have improved ecological conditions for prairie chickens by disrupting the foraging behavior of diurnal raptors that kill prairie chickens at lek sites. In support of this idea, raptor kills tended to be farther from turbines during the postconstruction period whereas mammalian kills were closer. Analyses of the major causes of mortality did not support our hypothesis because the odds of raptor predation were greater after development was completed. Most mortality losses of radio-marked females were due to predation, and losses to collision mortality or harvest were rare events. Low rates of natural mortality during fall and winter imply that harvest is likely to be additive mortality in prairie chickens. Wind energy development reduced the residual body mass of male Greater Prairie-Chickens at lek sites near turbines. Low values of residual body mass could have a negative impact on individual survival or fecundity rates, or may be related to predation risk and flight performance of males displaying at open lek sites. 8. We tested for impacts of wind power development on population numbers of prairie chickens with monitoring of male numbers at leks, and with genetic measures of population structure. Lek counts indicated that wind power development did not affect the population size of prairie chickens. Peak counts of males at leks were recorded the first year after construction was completed and the highest rates of population change were observed during the interval when the wind power facility was constructed. Population numbers of prairie chickens near and distant from turbines appeared to covary in parallel, probably because bird numbers were linked by dispersal movements. Estimates of population viability based on genetic diversity, effective population size and rates of population exchange did not show annual changes and were unaffected by wind development during our study. Estimates of relatedness among males at the same and different leks suggested that wind power development has either reduced dispersal rates or changed settlement patterns, leading to higher rates of relatedness among males displaying at the same lek site. 9. Greater Prairie-Chickens were not strongly affected by wind power development in Kansas. Negative impacts of wind power development included a trend for reductions in lek persistence near turbines, behavioral avoidance of turbines by females during their breeding season movements, and changes in the genetic structure of males at leks that were consistent with reduced dispersal or recruitment rates. We found no impacts of wind power development on nest site selection, female reproductive effort or nesting success, or population numbers. Positive impacts of wind power development included an increase in female survival rates. We hypothesized that the unexpected increase in female survival was related to changes in trophic interactions and disruption of the foraging behavior of raptors that kill prairie chickens at lek site. 10. Research funding for this project included a grant from the 20% Wind by 2030 Program of the Department of Energy (this final report), and grants from the Kansas Department of Wildlife, Parks and Tourism, the National Fish and Wildlife Federation, and initial funding from the National Wind Coordinating Collaborative. Research products from data collected during the preconstruction period have included five peer-reviewed research articles and two PhD dissertations at Kansas State University. Additional manuscripts are in review for possible publication in 2013-2014.

17 WIND ENERGY↗
DOE OSTI2015

Acoustic sensors for fission gas characterization: R and D skills devoted to innovative instrumentation in MTR, non-destructive devices in hot lab facilities and specific transducers for measurements of LWR rods in nuclear plants

First of all, we will present the main principle of the method. A piezoelectric transducer, driven by a pulse generator, generates the acoustic waves in a cavity that may be the fuel rod or a chamber connected to an instrumented rod. The composition determination consists in measuring the time of flight of the acoustic signal emitted. The pressure can be estimated by a calibration process, above the measurement of the amplitude of the signal. Two projects will then be detailed. The first project consists in the development of advanced instrumentation for in-pile experiments in Material Testing Reactor. It constitutes a main goal for the improvement of the nuclear fuel behavior knowledge. This acoustic method was tested with success during a first experiment called REMORA 3, and the results were used to differentiate helium and fission gas release kinetics under transient operating conditions. This experiment was lead at OSIRIS reactor (CEA Saclay, France). As a first step of the development program, we performed in-pile tests on the most sensitive component, i.e., the piezoelectric transducer. For this purpose, the active part of this sensor has been qualified on gamma and neutron radiations and at high temperature. Various industrial piezo-ceramics were exposed to a high activity Cobalt source for few days. The cumulated dose was ranged from 50 kGy up to 2 MGy. Next, these devices were placed inside a Material Test Reactor to investigate their reliability towards neutron fluence. The final fluence after 150 days of irradiation was up to 1.6.10{sup 21}n/cm{sup 2} (for thermal neutron). Irreversible variations have been measured. Next, a specific sensor has been implemented on an instrumented fuel rod and tested in the frame of a REMORA 3 Irradiation test. It was the first experiment under high mixed, temperature neutron and gamma flux. A first irradiation phase took place in March 2010 in the OSIRIS reactor and in November 2010 for the second step of the irradiation. The instrumented fuel rod incorporating the ultrasonic gas composition sensor was finally irradiated during 2 weeks in nominal conditions. Neutronics calculation will be performed in order to calculate the thermal and fast neutron fluence and the gamma dose absorbed by acoustic sensor. A first evaluation gives a thermal fluence about 4,5.10{sup 19} n/cm{sup 2}, a fast neutrons fluence about 4,5.1018 n/cm{sup 2} and a total gamma dose up to 0,25 MGy The maximal temperature during the irradiation test was about 150 C. Although the ultrasonic sensor appears to be damaged, the optimization of the electrical attack parameters and the development of a new signal processing maintain the measurement feasibility up the end of the irradiation campaign. It was the first time that the composition of fission gas has been monitored all along an irradiation experiment in a MTR, giving access to the gas release kinetics. New researches involve thick film transducers produced by screen-printing process in order to propose piezoelectric structures for harsh temperature and irradiation measurements. The second project consists in the development of a non-destructive device that can be directly applied on a LWR fuel rod. The problem to be solved relates to the measurement of the fission gas pressure and composition in a fuel rod using a non-destructive method. Fuel rod internal pressure is one of the safety criteria applied in nuclear power analyses. This criterion must be verified in order to avoid any fuel-cladding gap reopening risk and therefore any local clad ballooning. Apart from the safety implications, this parameter is also a fuel behaviour indicator and reflects the overall fuel performance in operation, but also during shipping and long-term storage. Rod internal pressure is one criterion amongst others, like cladding corrosion, against which the acceptable fuel burn-up limit is set. A sensor has been achieved in 2007. A full-scale hot cell test of the internal gas pressure and composition measurement by an acoustic sensor was conducted successfully between 2008 and 2010 on 5 high burn-up MOX fuel rods and 2 very high burn-up UO{sub 2} fuel rods in LECA Facility at Cadarache Centre. An improvement of this sensor has been proposed, allowing us to divide by two the uncertainty on the pressure measurement. In the case of hot-cell measurements, viscous liquid can be used to couple the sensor with the rod. For gas content with a pressure exceeding 15 bars and a 10% Xe/Kr ratio, such coupling may reduce relative acoustic method accuracy by ±7% for pressure measurement result and ±0.25 % for the assessment of gas composition. These results make it possible to demonstrate the feasibility of the technique on LWR fuel rods. The transducer and the associated methodology are now operational for non-destructive measurements in hot lab facilities and allow characterising the fission gas without puncturing the fuel rods. Up to now, any other non-destructive method can be proposed. A next step will be the development of an industrial application in a fuel storage pool in order to perform a large number of measurements on a fuel assembly in nuclear plants.

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2025

Initial Characterization of the NREL Large-Amplitude Motion Platform

The Large Amplitude Motion Platform (LAMP) at NREL represents a significant advancement in the controlled testing of Wave Energy Converters (WECs) under laboratory conditions. Originally designed by E2M as a six-degree-of-freedom (DOF) Stewart platform for flight simulation, LAMP has been adapted by NREL to facilitate the mounting and evaluation of WECs. This adaptation enables dry testing of WECs using motion profiles similar to the ocean, facilitating the iterative design, testing, and validation of WEC performance prior to ocean deployments. This report presents the initial work completed to characterize LAMP, with particular emphasis on its stability and operational capabilities across various single and multi-degree-of-freedom (DOF) motion profiles. The report includes planned comparisons at three distinct mass payloads, aimed at assessing the platform's positional accuracy, frequency response, and endurance over extended runtime periods. These experimental tests are critical for establishing the platform's limitations and ensuring that the data generated during WEC validation is both accurate and reproducible. The outcomes of this study not only contribute to a deeper understanding of LAMP's capabilities but also lay the groundwork for future advancements in WEC testing methodologies. By providing robust and reliable performance data within a controlled laboratory setting, the findings are expected to significantly enhance the development and commercialization of marine energy technologies. This report presents the initial findings of the LAMP Characterization work and proposed steps to further understand and characterize LAMP. Data collected during this work can be found on MHKDR at: https://mhkdr.openei.org/submissions/602 Note that this report shares the measured/found instantaneous maximum operating range of LAMP. For most applications the maximum operating range cannot be used for system health and longevity. The operating range and capabilities of LAMP will be evaluated on a case-by-case basis, single-DOF position, velocity, and acceleration values presented in Table 4a-c, and Table 5 should be taken as instantaneous absolute maximum values. Future use of LAMP will likely be limited to smaller values.

16 TIDAL AND WAVE POWER↗
DOE OSTI2014

Integrated testing of the Thales LPT9510 pulse tube cooler and the iris LCCE electronics

The Jet Propulsion Laboratory (JPL) has identified the Thales LPT9510 pulse tube cryocooler as a candidate low cost cryocooler to provide active cooling on future cost-capped scientific missions. The commercially available cooler can provide refrigeration in excess of 2 W at 100K for 60W of power. JPL purchased the LPT9510 cooler for thermal and dynamic performance characterization, and has initiated the flight qualification of the existing cooler design to satisfy near-term JPL needs for this cooler. The LPT9510 has been thermally tested over the heat reject temperature range of 0C to +40C during characterization testing. The cooler was placed on a force dynamometer to measure the selfgenerated vibration of the cooler. Iris Technology has provided JPL with a brass board version of the Low Cost Cryocooler Electronics (LCCE) to drive the Thales cooler during characterization testing. The LCCE provides precision closed-loop temperature control and embodies extensive protection circuitry for handling and operational robustness; other features such as exported vibration mitigation and low frequency input current filtering are envisioned as options that future flight versions may or may not include based upon the mission requirements. JPL has also chosen to partner with Iris Technology for the development of electronics suitable for future flight applications. Iris Technology is building a set of radiation-hard, flight-design electronics to deliver to the Air Force Research Laboratory (AFRL). Test results of the thermal, dynamic and EMC testing of the integrated Thales LPT9510 cooler and Iris LCCE electronics is presented here.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2017

Detailed modeling of electron emission for transpiration cooling of hypersonic vehicles

Electron transpiration cooling (ETC) is a recently proposed approach to manage the high heating loads experienced at the sharp leading edges of hypersonic vehicles. Computational fluid dynamics (CFD) can be used to investigate the feasibility of ETC in a hypersonic environment. In this paper, a modeling approach is presented for ETC, which includes developing the boundary conditions for electron emission from the surface, accounting for the space-charge limit effects of the near-wall plasma sheath. The space-charge limit models are assessed using 1D direct-kinetic plasma sheath simulations, taking into account the thermionically emitted electrons from the surface. The simulations agree well with the space-charge limit theory proposed by Takamura et al. for emitted electrons with a finite temperature, especially at low values of wall bias, which validates the use of the theoretical model for the hypersonic CFD code. The CFD code with the analytical sheath models is then used for a test case typical of a leading edge radius in a hypersonic flight environment. The CFD results show that ETC can lower the surface temperature of sharp leading edges of hypersonic vehicles, especially at higher velocities, due to the increase in ionized species enabling higher electron heat extraction from the surface. Finally, the CFD results also show that space-charge limit effects can limit the ETC reduction of surface temperatures, in comparison to thermionic emission assuming no effects of the electric field within the sheath.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2017

Space Nuclear Reactor Engineering

We needed to find a space reactor concept that could be attractive to NASA for flight and proven with a rapid turnaround, low-cost nuclear test. Heat-pipe-cooled reactors coupled to Stirling engines long identified as the easiest path to near-term, low-cost concept.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2021

Landscape-scale Characterization of Arctic Tundra Vegetation Composition, Structure, and Function with a Multi-sensor Unoccupied Aerial System: Supporting Data.

Airborne remote sensing data collected using the Brookhaven National Laboratory's (BNL) heavy-lift unoccupied aerial system (UAS) octocopter platform, the Osprey, operated by the Terrestrial Ecosystem Science and Technology (TEST) group (https://www.bnl.gov/testgroup). This package includes data from three flights flown over the NGEE-Arctic Council, Kougarok and Teller sites in July, 2018. The Osprey is a multi-sensor UAS platform that simultaneously measures very high spatial resolution optical red/green/blue (RGB) and thermal infrared (TIR) surface 'skin' temperature imagery, as well as surface reflectance at 1 nm intervals in the visible to near-infrared spectral range 350 - 1000 nm measured at regular intervals along each flight path. Derived image products include ortho-mosaiced RGB and TIR images, an RGB-based digital surface model (DSM) using the structure from motion (SfM) technique, digital terrain model (DTM), and a canopy height model (CHM). In addition, a VNIR surface reflectance file is provided for the trigger locations collected during each flight campaign. Ancillary aircraft data, flight mission parameters, and general flight conditions provided by the onboard flight and data collection computers are also included. Unprocessed and processed data products are included in this package (processing levels 0-3). Data and metadata are provided as text (*.txt, *.json, *.kml, *hdr, *.enp), tabular (*.dat, *.csv, *.waypoint, ENVI format (no extension)), point cloud (*.laz) and image (*.jpg, *.tif, *png) formats. This metadata document contains flight campaign, instrument and file metadata, along with a description of data processing levels, data products and file naming scheme.The Next-Generation Ecosystem Experiments: Arctic (NGEE Arctic), a research effort to reduce uncertainty in Earth System Models by developing a predictive understanding of carbon-rich Arctic ecosystems and feedbacks to climate. NGEE Arctic was supported by the Department of Energy?s Office of Biological and Environmental Research.The NGEE Arctic project had two field research sites: 1) located within the Arctic polygonal tundra coastal region on the Barrow Environmental Observatory (BEO) and the North Slope near Utqiagvik (Barrow), Alaska and 2) multiple areas on the discontinuous permafrost region of the Seward Peninsula north of Nome, Alaska.Through observations, experiments, and synthesis with existing datasets, NGEE Arctic provided an enhanced knowledge base for multi-scale modeling and contributed to improved process representation at global pan-Arctic scales within the Department of Energy's Earth system Model (the Energy Exascale Earth System Model, or E3SM), and specifically within the E3SM Land Model component (ELM).

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2024

UAS remote sensing (Osprey platform): Red-green-blue (RGB) imagery, thermal infrared (TIR) imagery, and canopy reflectance, Seward Peninsula, Alaska, 2019

Airborne remote sensing data collected using the Brookhaven National Laboratory's (BNL) heavy-lift unoccupied aerial system (UAS) octocopter platform - the Osprey - operated by the Terrestrial Ecosystem Science and Technology (TEST) group (https://www.bnl.gov/testgroup). This package includes data from 17 flights flown over the NGEE-Arctic Council Mile Maker 64 (MM64) and Teller MM27 sites in July, 2019. The Osprey is a multi-sensor UAS platform that simultaneously measures very high spatial resolution optical red/green/blue (RGB) and thermal infrared (TIR) surface "skin" temperature imagery, as well as surface reflectance at 1 nm intervals in the visible to near-infrared spectral range from ~350-1000 nm measured at regular intervals along each flight path. This package provide the Level 0 (raw, unprocessed) data collected by the Osprey platform. Ancillary aircraft data, flight mission parameters, and general flight conditions provided by the onboard flight and data collection computers are also included. Data and metadata are provided as text (*.txt, *.json), tabular (*.dat, *.csv, *.waypoint), and image (*.jpg) formats. This metadata document contains flight campaign, instrument and file metadata, along with a description of the L0 data, and file naming scheme. The Next-Generation Ecosystem Experiments: Arctic (NGEE Arctic), was a research effort to reduce uncertainty in Earth System Models by developing a predictive understanding of carbon-rich Arctic ecosystems and feedbacks to climate. NGEE Arctic was supported by the Department of Energy's Office of Biological and Environmental Research. The NGEE Arctic project had two field research sites: 1) located within the Arctic polygonal tundra coastal region on the Barrow Environmental Observatory (BEO) and the North Slope near Utqiagvik (Barrow), Alaska and 2) multiple areas on the discontinuous permafrost region of the Seward Peninsula north of Nome, Alaska. Through observations, experiments, and synthesis with existing datasets, NGEE Arctic provided an enhanced knowledge base for multi-scale modeling and contributed to improved process representation at global pan-Arctic scales within the Department of Energy's Earth system Model (the Energy Exascale Earth System Model, or E3SM), and specifically within the E3SM Land Model component (ELM).

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2019

Centrifuge with vector-seeking linkage

Technologies pertaining to a centrifuge that comprises a vector-seeking linkage are disclosed herein. In a general embodiment, the centrifuge comprises a spindle that is rotatable about an axis of rotation. The centrifuge also has an arm that is coupled to the spindle, and a vector-seeking linkage that is coupled to the arm. The vector-seeking linkage provides two rotational degrees of freedom with respect to a load coupled to the vector-seeking linkage. The centrifuge is well-suited for a variety of applications, including sensor testing, solution separation, and producing accelerations expected to be experienced during flight.

47 OTHER INSTRUMENTATION↗
DOE OSTI2015

Recycle of Am-241 obtained from long term stored plutonium for use in radioisotope power systems - 15035

Pu-238 has been used as a power source for spacecraft since the early days of space exploration. It has proven to be an effective source of power where the use of solar generated power is impractical. Its application for use in spacecraft power systems was developed by the USA and Russia who have spent many $ 100s of millions on its development and production. However, the original facilities for the production of Pu-238 are no longer in use and existing worldwide stockpiles have reduced to levels sufficient for only one or two further missions. Production of Pu-238 requires considerable facilities including a nuclear reactor and reprocessing plants that are very expensive to build and operate. The European Space Agency (ESA) has assessed the options for post-launch power generation in future European space missions and has made the decision to pursue the use of Am-241 as an alternative isotope to power future European Radioisotope Power Systems (RPS). What makes Am-241 attractive for the European market is its 100% isotopically pure production from the decay of Pu-241 in separated civil plutonium stockpiles. Historically, Europe has relied on collaborations with the USA or Russia to access these nuclear power sources. During 2009, the European Space Agency (ESA) funded a project to examine the cost and practicality of establishing a European source of material suitable for Radioisotope Power Systems (RPS). The study concluded that a small number of radioisotopes could be used in RPSs. On further review two leading candidates, Am-241 and Pu-238, were selected for further study. Whilst Pu-238 was recognized as the isotope of choice for use in RPSs, the costs of setting up a European based production facility was prohibitively expensive. Although Am-241 has a number of limitations compared to Pu-238, the much reduced production costs make Am-241 an attractive option for European based production of RPSs. Despite its lower power density of ∼ 0.11 Wth/g, Am-241 is viewed as a potential alternative to Pu-238 because of its availability within the nuclear fuel cycle. During the reprocessing of spent nuclear fuel plutonium is separated as a chemically pure PuO{sub 2} product, containing around 3-11% w/w of the Pu-241 isotope, and placed into storage. During storage the Pu-241 isotope beta decays to Am-241 with a half-life of 14.4 years. {sub 94}{sup 241}Pu → (β 14.4 y) {sub 95}{sup 241}Am. This process has resulted in many 100 kgs of americium growing into the civil plutonium stockpile in the UK; material that is of value in generating heat sources and is able to be recycled. The key benefit of Am-241 as a potential European RPS source isotope is the availability of feed material along with the facilities to process it. It is expected that aged civil PuO{sub 2} will contain 25-50 g Am-241 per kg PuO{sub 2} depending on the source. A conceptual flowsheet using facilities for separating americium from plutonium is expected to produce on average 8.4 kg Am/year. ESA are now following their published road-map of studies to develop flight ready RTGs and RHUs. This has included the development and testing of the flowsheet to be used for production of Am-241. The project has focused on underpinning the conceptual flowsheet, using aged plutonium in NNL's PuMA laboratory. This has underpinned the design of a plant to produce a steady supply of Am-241. The scope of the overall project is 'store to store' - the starting point is aged plutonium currently housed in existing Sellafield stores and the end point is the storage of separated plutonium and americium powders on the Sellafield site. The full scale process is planned to be housed within the NNL's Central Laboratory in an existing facility designed for plutonium active operations. (authors)

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2014

A new neutron time-of-flight detector for fuel-areal-density measurements on OMEGA

A new neutron time-of-flight (nTOF) detector for fuel-areal-density measurements in cryogenic DT implosions was installed on the OMEGA Laser System. The nTOF detector has a cylindrical thin-wall, stainless-steel, 8-in.-diam, 4-in.-thick cavity filled with an oxygenated liquid xylene scintillator. Four gated photomultiplier tubes (PMTs) with different gains are used to measure primary DT and D{sub 2} neutrons, down-scattered neutrons in nT and nD kinematic edge regions, and to study tertiary neutrons in the same detector. The nTOF detector is located 13.4 m from target chamber center in a well-collimated line of sight. The design details of the nTOF detector, PMT optimization, and test results on OMEGA will be presented.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗