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DOE OSTI2022

3013 Inner Container Closure Weld Region (ICCWR) Characterization by Wide Area 3D Measurement System (WAMS) Analysis (FY21 Progress Report)

As part of the 3013 Surveillance Program, through-wall penetration from stress corrosion cracking (SCC) of the 3013 inner containers has been identified as the most credible condition for failure withing the 50- years lifetime. Chlorides contained in Pu-bearing material, together with intra-canister humidity levels, metallurgical conditions, and internal stresses have been found to produce corrosion in the Inner Container Closure Weld Region (ICCWR) of the 3013 canister system. A Laser Confocal Microscope (LCM) is used as part of the 3013 Surveillance Program protocol to identify the prevalence of corrosion and corrosionrelated cracking in the ICCWR2. With the LCM, a close visual examination is made of the ICCWR surface along with measurements of corrosion-related features. LCM inspections produce immense amounts of image data that is time intensive to analyze. There is also a 9-year backlog of images, with approximately 49 canisters that must be evaluated. To expedite data analysis and reduce the amount of generated data, a Wide Area 3D Measurement System (WAMS) microscope has been added to the examination protocol. Although WAMS is a lower resolution microscope, small features of interest can be still identified. The advantage of collecting data for the full circumference using the WAMS is that it can take about 1/16 of the time needed with the LCM. Both systems offer capabilities that combined can be utilized to expedite the examination of the ICCWR. The WAMS is an efficient system for screening and identification of corrosion features while the LCM can be utilized to obtain higher resolution images areas identified by the WAMS. This report explains and justifies the data collection methods used with the WAMS. It includes a summary of the data generated by WAMS in FY21. The goals set for data collection in FY21 were met. A total of twenty-two DE’s were imaged, and analysis was carried out on eleven samples. The analyzed samples showed large numbers of potential cracks and pits distributed throughout the surfaces. Lastly, to explain the advantages of the WAMS, its capabilities were compared to those of a simpler microscope. Micrographs of the samples imaged in FY21 and those analyzed are included in the appendices.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2023

Predicting magnetic properties of single-molecule magnets from self-interaction-free density-functional theory (Final Report)

In this project we investigated electronic structure of an intermediate-sized copper-based molecule and magnetic and hyperfine properties of several small non-magnetic and magnetic molecules including transition-metal elements by applying self-interaction corrections to density functional theory (DFT). In a sufficient number of cases, DFT-calculated electronic structure and magnetic properties of single-molecule magnets qualitatively differ from corresponding experimental data. This is partly due to self-interacting electrons within the DFT formalism. Recently, an efficient method to correct the self-interactions was proposed, i.e., Fermi-Lowdin prbital (FLO) based self-interaction corrected (SIC) methodology, within DFT. Henceforth, this method is referred to as FLO-SIC method which exists in FLOSIC code. We used this FLO-SIC method for our studies of electronic structure and magnetic and hyperfine properties of small magnetic molecules and non-magnetic molecules. Our study will provide insight into predictions of magnetic properties of single-molecule magnets where self-interaction corrections play a critical role. There are two components of this project. In the first work, we studied the electronic structure of a planar mononuclear Cu-based molecule in two oxidation states, using DFT with the FLO-SIC method. We chose this system because it is small enough and it includes a transition metal element. We found that the standard FLO-SIC method takes too much compute time even for the small transition-metal molecule and so we slightly modified the method in order to expedite the process. In the dianionic state, we found that the FLO-SIC spin density agrees quantitatively with accurate quantum chemistry methods, while DFT spin density without self-interaction corrections are severely deviated from the quantum chemistry methods. We also showed that the energy gap between the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of the dianionic state is larger than that of the monoanionic state. This result is consistent with experimental data. In the second work, we investigated how the interaction between the electron spin and nuclear spin is affected by electron self-interactions within small non-magnetic and magnetic molecules. Such an interaction is called hyperfine interaction. For molecules without significant orbital angular momentum, the hyperfine interaction consists of Fermi contact and dipolar interaction terms. Since the Fermi contact term depends on electron spin density at the nuclear site, it would be highly affected by self-interaction corrections. Therefore, we calculated the hyperfine interaction for the small molecules using DFT with the slightly modified expedited FLO-SIC method which was obtained in the first work, and compared the results to experimental data and DFT calculations without self-interaction corrections. We found significant improvement of the Fermi contact term computed using the FLO-SIC method for small magnetic molecules. Overall, the first and second work provided positive outlook of application of the FLO-SIC method to magnetic molecules and systems including transition-metal elements.

36 MATERIALS SCIENCE↗

DOE OSTI2023

Support for the Second MOSAiC Science Conference support (Final Report)

This is a final report for a conference support project. The US Department of Energy’s Atmospheric System Research Program provided funding support for the Second MOSAiC Science Conference. MOSAiC is the Multidisciplinary drifting Observatory for the Study of Arctic Climate, a yearlong, international expedition into the rapidly changing Arctic sea ice. The expedition collected measurements of the atmosphere, sea ice, and ocean to study coupled physical, chemical, and biological processes. The Second MOSAiC Science Conference provided an important opportunity to bring the MOSAiC-interested community together to discuss MOSAiC data, scientific analyses, synthesis, modeling activities, and more. Overall, the conference was a significant success and has motivated and facilitated a great deal of ongoing research. The support provide by this project was used along with support from other agencies to implement a participant support program that enabled participation in the conference by a diverse collection of researchers from many different countries and disciplines, 60% of whom were female. Most of these participants were Early Career Researchers. Participation by these researchers was vital to the overall success of the conference and has helped to build leadership and research skills for the participants that will serve both themselves and the broader scientific community in the future.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2024

Flat and Level Analysis Tool (FLAT) for real-time automated segmentation and analysis of concrete slab point clouds

In the United States, the flatness and levelness of concrete floors during construction is traditionally specified by a maximum allowable gap under a 3 meter straightedge. However, the straightedge method is inexact and rarely representative of the entire floor since the technician is free to choose any location on the floor to perform the measurement. In cases requiring a higher degree of precision and repeatability, concrete floor flatness and levelness can be measured using the standard test method ASTM E1155. With the recent introduction of advanced surveying instruments such as robotic theodolites and terrestrial laser scanners (TLS), the means now exist to modernize and expedite the measurement of floor flatness and levelness. This paper details the development and demonstration of a digital tool, named the Flat and Level Analysis Tool (FLAT), to automate and expedite the segmentation and analysis of flatness and levelness from dense point cloud data of concrete floor slabs. Segmentation algorithms were developed using unsupervised machine learning to extract the set of points belonging to the concrete floor slab from a full 360 scan of a construction site. After segmentation, automated analysis algorithms report the results according to the standard method. The developed algorithms were demonstrated on a dense point cloud captured from a concrete slab-on-grade at a construction site. Results show that the digital tool can quickly provide estimates for floor flatness and levelness with minimal human involvement with comparable accuracy to manual methods.

Hayes, Nolan↗

DOE OSTI2020

Ship-based measurements of ice nuclei concentrations over the Arctic, Atlantic, Pacific and Southern oceans

Ambient concentrations of ice-forming particles measured during ship expeditions are collected and summarised with the aim of determining the spatial distribution and variability in ice nuclei in oceanic regions. The presented data from literature and previously unpublished data from over 23 months of ship-based measurements stretch from the Arctic to the Southern Ocean and include a circumnavigation of Antarctica. In comparison to continental observations, ship-based measurements of ambient ice nuclei show 1 to 2 orders of magnitude lower mean concentrations. To quantify the geographical variability in oceanic areas, the concentration range of potential ice nuclei in different climate zones is analysed by meridionally dividing the expedition tracks into tropical, temperate and polar climate zones. We find that concentrations of ice nuclei in these meridional zones follow temperature spectra with similar slopes but vary in absolute concentration. Typically, the frequency with which specific concentrations of ice nuclei are observed at a certain temperature follows a log-normal distribution. A consequence of the log-normal distribution is that the mean concentration is higher than the most frequently measured concentration. Finally, the potential contribution of ship exhaust to the measured ice nuclei concentration on board research vessels is analysed as function of temperature. We find a sharp onset of the influence at approximately -36 °C but none at warmer temperatures that could bias ship-based measurements.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2023

Annual cycle of aerosol properties over the central Arctic during MOSAiC 2019–2020 – light-extinction, CCN, and INP levels from the boundary layer to the tropopause

Abstract. The MOSAiC (Multidisciplinary drifting Observatory for the Study of Arctic Climate) expedition was the largest Arctic field campaign ever conducted. MOSAiC offered the unique opportunity to monitor and characterize aerosols and clouds with high vertical resolution up to 30 km height at latitudes from 80 to 90∘ N over an entire year (October 2019 to September 2020). Without a clear knowledge of the complex aerosol layering, vertical structures, and dominant aerosol types and their impact on cloud formation, a full understanding of the meteorological processes in the Arctic, and thus advanced climate change research, is impossible. Widespread ground-based in situ observations in the Arctic are insufficient to provide these required aerosol and cloud data. In this article, a summary of our MOSAiC observations of tropospheric aerosol profiles with a state-of-the-art multiwavelength polarization Raman lidar aboard the icebreaker Polarstern is presented. Particle optical properties, i.e., light-extinction profiles and aerosol optical thickness (AOT), and estimates of cloud-relevant aerosol properties such as the number concentration of cloud condensation nuclei (CCN) and ice-nucleating particles (INPs) are discussed, separately for the lowest part of the troposphere (atmospheric boundary layer, ABL), within the lower free troposphere (around 2000 m height), and at the cirrus level close to the tropopause. In situ observations of the particle number concentration and INPs aboard Polarstern are included in the study. A strong decrease in the aerosol amount with height in winter and moderate vertical variations in summer were observed in terms of the particle extinction coefficient. The 532 nm light-extinction values dropped from >50 Mm−1 close to the surface to <5 Mm−1 at 4–6 km height in the winter months. Lofted, aged wildfire smoke layers caused a re-increase in the aerosol concentration towards the tropopause. In summer (June to August 2020), much lower particle extinction coefficients, frequently as low as 1–5 Mm−1, were observed in the ABL. Aerosol removal, controlled by in-cloud and below-cloud scavenging processes (widely suppressed in winter and very efficient in summer) in the lowermost 1–2 km of the atmosphere, seems to be the main reason for the strong differences between winter and summer aerosol conditions. A complete annual cycle of the AOT in the central Arctic could be measured. This is a valuable addition to the summertime observations with the sun photometers of the Arctic Aerosol Robotic Network (AERONET). In line with the pronounced annual cycle in the aerosol optical properties, typical CCN number concentrations (0.2 % supersaturation level) ranged from 50–500 cm−3 in winter to 10–100 cm−3 in summer in the ABL. In the lower free troposphere (at 2000 m), however, the CCN level was roughly constant throughout the year, with values mostly from 30 to 100 cm−3. A strong contrast between winter and summer was also given in terms of ABL INPs which control ice production in low-level clouds. While soil dust (from surrounding continents) is probably the main INP type during the autumn, winter, and spring months, local sea spray aerosol (with a biogenic aerosol component) seems to dominate the ice nucleation in the ABL during the summer months (June–August). The strong winter vs. summer contrast in the INP number concentration by roughly 2–3 orders of magnitude in the lower troposphere is, however, mainly caused by the strong cloud temperature contrast. A unique event of the MOSAiC expedition was the occurrence of a long-lasting wildfire smoke layer in the upper troposphere and lower stratosphere. Our observations suggest that the smoke particles frequently triggered cirrus formation close to the tropopause from October 2019 to May 2020.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2025

Estimation of the radiation budget during MOSAiC based on ground-based and satellite remote sensing observations

An accurate representation of the radiation budget is essential for investigating the impact of clouds on the climate system, especially in the Arctic, an environment highly sensitive to complex and rapid environmental changes. In this study, we analyse a unique dataset of observations from the central Arctic made during the MOSAiC (Multidisciplinary drifting Observatory for the Study of Arctic Climate) expedition in conjunction with state-of-the-art satellite products from CERES (Clouds and the Earth's Radiant Energy System) to investigate the radiative effect of clouds and radiative closure at the surface and the top of the atmosphere (TOA). We perform a series of radiative transfer simulations using derived cloud macro- and microphysical properties as inputs to the simulations for the entire MOSAiC period, comparing our results to collocated satellite products and ice-floe observations. The radiative closure biases were generally within the instrumental uncertainty, indicating that the simulations are sufficiently accurate to reproduce the radiation budget during MOSAiC. Comparisons of the simulated radiation budget relative to CERES show similar values in the terrestrial flux but relatively large differences in the solar flux, which are attributed to a lower surface albedo and a possible underestimation of atmospheric opacity by CERES. While the simulation results were consistent with the observations, more detailed analyses reveal an overestimation of simulated cloud opacity for cases involving geometrically thick ice clouds. In the annual mean, we found that, during the MOSAiC expedition, the presence of clouds leads to a loss of 5.2 W m −2 of the atmosphere–surface system to space, while the surface gains 25.0 W m −2 and the atmosphere is cooled by 30.2 W m −2 .

54 ENVIRONMENTAL SCIENCES↗

NASA NTRS1971

Airborne auroral data and satellite data analysis

The photometric data taken during the 1969 CV990 expedition were analyzed. It was found that the so-called soft auroral zone extends right through the night side auroral zone. The soft precipitation is a permanent feature of the night side auroral zone and probably signifies the position of the plasma sheet. The harder auroras which include the conventional visible auroras occur less frequently. The intensity and mean energy of auroral electrons is correlated suggesting that the fluctuation in auroral intensity comes primarily from the variability of the acceleration mechanism rather than the variations in the particle population densities. During the 1969 CV990 expedition, coordinated data was taken with the particle experiments on OV1-18 and ATS-5 satellites. The satellite data was reduced to facilitate coordinated investigations with the airborne experimenters. The airborne photometric lambda 5200 NI data were analyzed and the effective life time was found to be 4.5 minutes.

Mende, S. B.↗

NASA NTRS1978

Remote sensing of the boundary layer over the oceans

The paper explores the possibility of remotely sensing the boundary layer structure over the oceans by means of the Nimbus 4 IR Interferometric Spectrometer (IRIS) measurements in the water vapor bands. It is found from theoretical considerations that the moderately strong spectral lines in the 9-micron water vapor window region contain useful information about the lowest layers in the atmosphere. The difference between the observed line strength and the theoretically predicted line strength provides information about the departure in the atmospheric temperature and water vapor profiles from standard conditions. The observations of METEOR oceanographic expedition over the North and South Atlantic, and the Indian Ocean expedition make it possible to model the inversion conditions. It is concluded that significant characteristics of the temperature and water vapor profiles in the boundary layer of the atmosphere can be remotely sensed using the water vapor spectral measurements over the oceans.

Prabhakara, C.↗

NASA NTRS1979

NASA takes stock

The history of NASA activities and achievements in the past decade is reviewed with consideration given to the Apollo expeditions and the post-Apollo planetary exploration. Progress in spaceborne astronomy and in satellite communications is characterized as revolutionary. It is also noted that Landsat alone may eventually repay the United States for the cost of the entire space program. Special attention is given to the Shuttle program which will be the key to all operations in space for the next decade including the Galileo mission to Jupiter (1982) and the Space Telescope (1983). Future missions could include a Venus orbiter with imaging radar to finally penetrate the cloud cover of the planet and to map its surface; a rover or sample return expedition to Mars; a Saturn orbiter combined with a probe of its Titan satellite, and an examination of Halley's Comet. Finally the next decade should bring the data needed to make a 'go' or 'no go' decision on the concept of SPS that would beam solar energy into earth stations.

Frosch, R. A.↗

NASA NTRS1982

Sounding rockets in Antarctica

Sounding rockets are versatile tools for scientists studying the atmospheric region which is located above balloon altitudes but below orbital satellite altitudes. Three NASA Nike-Tomahawk sounding rockets were launched from Siple Station in Antarctica in an upper atmosphere physics experiment in the austral summer of 1980-81. The 110 kg payloads were carried to 200 km apogee altitudes in a coordinated project with Arcas rocket payloads and instrumented balloons. This Siple Station Expedition demonstrated the feasibility of launching large, near 1,000 kg, rocket systems from research stations in Antarctica. The remoteness of research stations in Antarctica and the severe environment are major considerations in planning rocket launching expeditions.

Alford, G. C.↗

NASA NTRS1985

The stratospheric aerosol particle measurement by balloon at Syowa Station (69.00 deg S, 39.35 deg E): Outline of special sonde (rubber) campaign JARE 24

During the period of AMA (Antarctic Middle Atmosphere), various style balloons were used to measure atmospheric parameters at Syowa Station (69.00 deg S, 39.35 deg E), Antarctica. The measurements which were made using balloons specially designed to monitor stratospheric aerosol particles are discussed. This type balloon was first used by JARE (Japan Antarctic Research Expedition) 24th Team in 1983. Until that time, the Japan Antarctic Research Expedition Team had been using only a large plastic balloon to monitor various minor constituents in the stratosphere. The plastic balloon was very useful, but it took a long time to arrange a balloon launching. Additionally, launching time strongly depended on weather conditions. A timely launching of the balloon was carried out with this specially designed sonde.

Iwasaka, Y.↗

NASA NTRS1986

NASA/JPL aircraft SAR operations for 1984 and 1985

The NASA/JPL aircraft synthetic aperture radar (SAR) was used to conduct major data acquisition expeditions in 1983 through 1985. Substantial improvements to the aircraft SAR were incorporated in 1981 through 1984 resulting in an imaging radar that could simultaneously record all four combinations of linear horizontal and vertical polarization (HH, HV, VH, VV) using computer control of the radar logic, gain setting, and other functions. Data were recorded on high-density digital tapes and processed on a general-purpose computer to produce 10-km square images with 10-m resolution. These digital images yield both the amplitude and phase of the four polarizations. All of the digital images produced so far are archived at the JPL Radar Data Center and are accessible via the Reference Notebook System of that facility. Sites observed in 1984 and 1985 included geological targets in the western United States, as well as agricultural and forestry sites in the Midwest and along the eastern coast. This aircraft radar was destroyed in the CV-990 fire at March Air Force Base on 17 July 1985. It is being rebuilt for flights in l987 and will likely be operated in a mode similar to that described here. The data from 1984 and 1985 as well as those from future expeditions in 1987 and beyond will provide users with a valuable data base for the multifrequency, multipolarization Spaceborne Imaging Radar (SIR-C) scheduled for orbital operations in the early 1990's.

Thompson, T. W.↗

NASA NTRS1988

Infrared measurements of column amounts of stratospheric constituents in the Antarctic winter, 1987

The discovery of Farman et al. of recent large depletions of ozone in the Antarctic stratosphere in the austral spring has aroused great interest because of its serious potential consequences, as well as its surprising nature. An airborne expedition, including 21 experiments on two aircraft, was mounted for Punta Arenas, Chile, in August and September, 1987, to gather a wide range of data to understand the origins and implications of this phenomenon, known as the ozone hole. As a part of this expedition, a high resolution Fourier transform spectrometer was flown on the DC-8, measuring the column amount of a number of trace gases above the flight altitude. Column results are presented only from the flight of September 21; results from other flights are included in an accompanying paper. The deduced column for ozone HCl, and NO2 deduced from the spectra, plotted as a function of latitude are shown. It should be noted that there are many other factors varying as well as the latitude, but latitude seems to be the variable which most clearly provides a passage across the vortex boundary. It can be seen that south 76 degrees S., the column of ozone, HCl, and NO2, all decreas markedly, The ratio of HCl to Hf, normally about 5:1 in midlatitudes, approaches unity. Clearly the chemistry of chlorine and nitrogen are disturbed in the region of low ozone. While dynamical theories could perhaps explain a reduction of these three gases in the same region, since all are of stratospheric origin, it is difficult to see how any purely dynamical mechanism could produce the observed HCl:HF ratio, since the two gases have similar origins. A close look at other species to be reported as well as the correlation with other measurements, such as ClO supports the conclusion that the ozone depletion is a result of chemical processes which deplete HCl and NOx relative to the midlatitude situation.

Mankin, William G.↗

NASA NTRS1988

Exploration Studies Technical Report - Volume 3: Special Reports, Studies, and Indepth Systems Assessments

Interplanetary flight↗

NASA NTRS1988

Exploration Studies Technical Report - Volume 1: Technical Summary

The Office of Exploration (OEXP) at NASA Headquarters has been tasked with defining and recommending alternatives for an early 1990's national decision on a focused program of human exploration of the solar system. The Mission Analysis and System Engineering (MASE) group, which is managed by the Exploration Studies Office at the Lyndon B. Johnson Space Center, is responsible for coordinating the technical studies necessary for accomplishing such a task. This technical report, produced by the MASE, describes the process that has been developed in a case study approach. The four case studies developed in FY88 include: 1. Human Expedition to Phobos 2. Human Expedition to Mars 3. Lunar Observatory 4. Lunar Outpost to Early Mars Evolution The final outcome of this effort is a set of programmatic and technical conclusions and recommendations for the following year's work.

Lunar Mining & Oxygen Production↗

NASA NTRS1988

Exploration Studies Technical Report - Volume 2: Studies Approach and Results

The NASA Office of Exploration has been tasked with defining and recommending alternatives for an early 1990's national decision on a focused program of human exploration of the solar system. The Mission Analysis and System Engineering (MASE) group, which is managed by the Exploration Studies Office at the Johnson Space Center, is responsible for coordinating the technical studies necessary for accomplishing such a task. This technical report describes the process that has been developed in a case study approach. The four case studies that were developed in FY88 include: 1. Human expedition to Phobos 2. Human expeditions to Mars 3. Lunar observatory 4. Lunar outpost to early Mars evolution The final outcome of this effort is a set of programmatic and technical conclusions and recommendations for the following year's work. Volume 2 describes the case study process, the technical results of each of the case studies, and opportunities for additional study. Included in the discussion of each case study is a description of the mission key features and profile. Mission definition and manifesting are detailed, followed by a description of the mission architecture and infrastructure. Systems concepts for the required orbital nodes, transportation systems, and planetary surface systems are discussed. Prerequisite implementation plans resulting from the synthesized case studies are described and in-depth assessments are presented.

Interplanetary flight↗

NASA NTRS1989

Exploration case studies

NASA's Office of Exploration has undertaken four case studies for prospective expansion of manned space activities beyond earth orbit. The subjects of these studies are (1) an expedition to the Martian moon Phobos; (2) a three-mission expedition to Mars; (3) the construction of a man-tended lunar observatory; and (4) the construction of a lunar outpost to serve as the basis for construction of a Martian outpost. The fourth alternative would follow the recommendation of the National Commission on Space for the creation of a 'bridge between worlds' in which explorers would develop ways in which to 'live off the land' in a space environment.

Underwood, Jimmy M.↗