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DOE OSTI2020

Code package for calculating modified cosmic ionization and thermal histories with dark matter and other exotic energy injections

Here we present a new public Python package, DarkHistory, for computing the effects of dark matter annihilation and decay on the temperature and ionization history of the early universe. DarkHistory simultaneously solves for the evolution of the free electron fraction and gas temperature, and for the cooling of annihilation/decay products and the secondary particles produced in the process. Consequently, we can self-consistently include the effects of both astrophysical and exotic sources of heating and ionization, and automatically take into account backreaction, where modifications to the ionization/temperature history in turn modify the energy-loss processes for injected particles. We introduce a number of worked examples, demonstrating how to use the code in a range of different configurations, in particular for arbitrary dark matter masses and annihilation/decay final states. Possible applications of DarkHistory include mapping out the effects of dark matter annihilation/decay on the global 21 cm signal and the epoch of reionization, as well as the effects of exotic energy injections other than dark matter annihilation/decay. The code is available at https://github.com/hongwanliu/DarkHistory with documentation at https://darkhistory.readthedocs.io. Data files required to run the code can be downloaded at https://doi.org/10.7910/DVN/DUOUWA.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2015

Simulation of multi-photon emission isotopes using time-resolved SimSET multiple photon history generator

Abstract-Multiple-photon emitters, such as In-111 or Se-75, have enormous potential in the field of nuclear medicine imaging. For example, Se-75 can be used to investigate the bile acid malabsorption and measure the bile acid pool loss. The simulation system for emission tomography (SimSET) is a well-known Monte Carlo simulation (MCS) code in nuclear medicine for its high computational efficiency. However, current SimSET cannot simulate these isotopes due to the lack of modeling of complex decay scheme and the time-dependent decay process. To extend the versatility of SimSET for simulation of those multi-photon emission isotopes, a time-resolved multiple photon history generator based on SimSET codes is developed in present study. For developing the time-resolved SimSET (trSimSET) with radionuclide decay process, the new MCS model introduce new features, including decay time information and photon time-of-flight information, into this new code. The half-life of energy states were tabulated from the Evaluated Nuclear Structure Data File (ENSDF) database. The MCS results indicate that the overall percent difference is less than 8.5% for all simulation trials as compared to GATE. To sum up, we demonstrated that time-resolved SimSET multiple photon history generator can have comparable accuracy with GATE and keeping better computational efficiency. The new MCS code is very useful to study the multi-photon imaging of novel isotopes that needs the simulation of lifetime and the time-of-fight measurements. (authors)

07 ISOTOPE AND RADIATION SOURCES↗

DOE OSTI2014

Land-use history alters contemporary insect herbivore community composition and decouples plant-herbivore relationships

1. Past land use can create altered soil conditions and plant communities that persist for decades, although the effects of these altered conditions on consumers are rarely investigated. 2. Using a large-scale field study at 36 sites in longleaf pine (Pinus palustris) woodlands, we examined whether historic agricultural land use leads to differences in the abundance and community composition of insect herbivores (grasshoppers, families Acrididae and Tettigoniidae). 3. We measured the cover of six plant functional groups and several environmental variables to determine whether historic agricultural land use affects the relationships between plant cover or environmental conditions and grasshopper assemblages. 4. Land-use history had taxa-specific effects and interacted with herbaceous plant cover to alter grasshopper abundances, leading to significant changes in community composition. Abundance of most grasshopper taxa increased with herbaceous cover in woodlands with no history of agriculture, but there was no relationship in post-agricultural woodlands. We also found that grasshopper abundance was negatively correlated with leaf litter cover. Soil hardness was greater in post-agricultural sites (i.e. more compacted) and was associated with grasshopper community composition. Both herbaceous cover and leaf litter cover are influenced by fire frequency, suggesting a potential indirect role of fire on grasshopper assemblages. 5. Our results demonstrate that historic land use may create persistent differences in the composition of grasshopper assemblages, while contemporary disturbances (e.g. prescribed fire) may be important for determining the abundance of grasshoppers, largely through the effect of fire on plants and leaf litter. Therefore, our results suggest that changes in the contemporary management regimes (e.g. increasing prescribed fire) may not be sufficient to shift the structure of grasshopper communities in post-agricultural sites towards communities in nonagricultural habitats. Rather, repairing degraded soil conditions and restoring plant communities are likely necessary for restoring grasshopper assemblages in post-agricultural woodlands.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2022

Plant carbohydrate storage: intra- and inter-specific trade-offs reveal a major life history trait

Trade-offs among carbon sinks constrain how trees physiologically, ecologically, and evolutionarily respond to their environments. These trade-offs typically fall along a productive growth to conservative, bet-hedging continuum. How nonstructural carbohydrates (NSCs) stored in living tree cells (known as carbon stores) fit in this trade-off framework is not well understood. Here, we examined relationships between growth and storage using both within species genetic variation from a common garden, and across species phenotypic variation from a global database. We demonstrate that storage is actively accumulated, as part of a conservative, bet-hedging life history strategy. Storage accumulates at the expense of growth both within and across species. Within the species Populus trichocarpa, genetic trade-offs show that for each additional unit of wood area growth (in cm 2 yr –1 ) that genotypes invest in, they lose 1.2 to 1.7 units (mg g –1 NSC) of storage. Across species, for each additional unit of area growth (in cm 2 yr –1 ), trees, on average, reduce their storage by 9.5% in stems and 10.4% in roots. Our findings impact our understanding of basic plant biology, fit storage into a widely used growth-survival trade-off spectrum describing life history strategy, and challenges the assumptions of passive storage made in ecosystem models today.

59 BASIC BIOLOGICAL SCIENCES↗

DOE OSTI2014

SU-E-T-347: Validation of the Condensed History Algorithm of Geant4 Using the Fano Test

Purpose: To validate the condensed history algorithm and physics of the Geant4 Monte Carlo toolkit for simulations of ionization chambers (ICs). This study is the first step to validate Geant4 for calculations of photon beam quality correction factors under the presence of a strong magnetic field for magnetic resonance guided linac system applications. Methods: The electron transport and boundary crossing algorithms of Geant4 version 9.6.p02 were tested under Fano conditions using the Geant4 example/application FanoCavity. User-defined parameters of the condensed history and multiple scattering algorithms were investigated under Fano test conditions for three scattering models (physics lists): G4UrbanMscModel95 (PhysListEmStandard-option3), G4GoudsmitSaundersonMsc (PhysListEmStandard-GS), and G4WentzelVIModel/G4CoulombScattering (PhysListEmStandard-WVI). Simulations were conducted using monoenergetic photon beams, ranging from 0.5 to 7 MeV and emphasizing energies from 0.8 to 3 MeV. Results: The GS and WVI physics lists provided consistent Fano test results (within ±0.5%) for maximum step sizes under 0.01 mm at 1.25 MeV, with improved performance at 3 MeV (within ±0.25%). The option3 physics list provided consistent Fano test results (within ±0.5%) for maximum step sizes above 1 mm. Optimal parameters for the option3 physics list were 10 km maximum step size with default values for other user-defined parameters: 0.2 dRoverRange, 0.01 mm final range, 0.04 range factor, 2.5 geometrical factor, and 1 skin. Simulations using the option3 physics list were ∼70 – 100 times faster compared to GS and WVI under optimal parameters. Conclusion: This work indicated that the option3 physics list passes the Fano test within ±0.5% when using a maximum step size of 10 km for energies suitable for IC calculations in a 6 MV spectrum without extensive computational times. Optimal user-defined parameters using the option3 physics list will be used in future IC simulations to calculate beam quality correction factors under the presence of a magnetic field. Elekta-MD Anderson Research Agreement.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

DOE OSTI2022

Biomineralization: Integrating mechanism and evolutionary history

Calcium carbonate (CaCO 3 ) biomineralizing organisms have played major roles in the history of life and the global carbon cycle during the past 541 Ma. Both marine diversification and mass extinctions reflect physiological responses to environmental changes through time. An integrated understanding of carbonate biomineralization is necessary to illuminate this evolutionary record and to understand how modern organisms will respond to 21st century global change. Biomineralization evolved independently but convergently across phyla, suggesting a unity of mechanism that transcends biological differences. In this review, we combine CaCO 3 skeleton formation mechanisms with constraints from evolutionary history, omics, and a meta-analysis of isotopic data to develop a plausible model for CaCO 3 biomineralization applicable to all phyla. The model provides a framework for understanding the environmental sensitivity of marine calcifiers, past mass extinctions, and resilience in 21st century acidifying oceans. Thus, it frames questions about the past, present, and future of CaCO 3 biomineralizing organisms.

60 APPLIED LIFE SCIENCES↗

DOE OSTI2023

Diffuse Reflectance Spectroscopy and Principal Component Analysis to Retrospectively Determine Production History of Plutonium Dioxide

Diffuse reflectance spectroscopy measurements in the shortwave infrared (930–1600 nm) spectral region were acquired for Pu 2 (C 2 O 4 ) 3 •9H 2 O and its thermal decomposition product, PuO 2 . We analyzed a total of eight PuO 2 samples that were produced at different calcination temperatures (300, 350, 450, 525, 600, 675, 750, and 900 °C). Our goal was to identify spectroscopic fingerprints that could be used to gain retrospective information regarding the production parameters of these important nuclear compounds. The diffuse reflectance spectrum of Pu 2 (C 2 O 4 ) 3 •9H 2 O features several broad bands that currently preclude detailed analysis. However, all PuO 2 samples produced relatively sharp spectral features that got sharper and more intense for samples that were produced at higher calcination temperatures. The electronic band observed at 1433 nm in the diffuse reflectance spectra of PuO 2 was found to be a sensitive indicator of crystallinity; a result that is corroborated by ancillary Raman spectroscopy measurements. Principal component analysis of diffuse reflectance spectra was able to clearly rank and categorize PuO 2 samples based on the calcination temperature that was employed during their production. Thus, we show herein that important retrospective information pertaining to the process history of PuO 2 can be gained through the relatively simplistic combination of diffuse reflectance spectroscopy and principal component analysis. This discovery presents a new method for determining the provenance and process history of PuO 2 and should have an impact in the fields of nuclear forensics and nuclear nonproliferation.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2015

The plant Polycomb repressive complex 1 (PRC1) existed in the ancestor of seed plants and has a complex duplication history

Background: Polycomb repressive complex 1 (PRC1) is an essential protein complex for plant development. It catalyzes ubiquitination of histone H2A that is an important part of the transcription repression machinery. Absence of PRC1 subunits in Arabidopsis thaliana plants causes severe developmental defects. Many aspects of the plant PRC1 are elusive, including its origin and phylogenetic distribution. Results: We established the evolutionary history of the plant PRC1 subunits (LHP1, Ring1a-b, Bmi1a-c, EMF1, and VRN1), enabled by sensitive phylogenetic methods and newly sequenced plant genomes from previously unsampled taxonomic groups. We showed that all PRC1 core subunits exist in gymnosperms, earlier than previously thought, and that VRN1 is a recent addition, found exclusively in eudicots. The retention of individual subunits in chlorophytes, mosses, lycophytes and monilophytes indicates that they can moonlight as part of other complexes or processes. Moreover, we showed that most PRC1 subunits underwent a complex, duplication-rich history that differs significantly between Brassicaceae and other eudicots. Conclusions: PRC1 existed in the last common ancestor of seed plants where it likely played an important regulatory role, aiding their radiation. The presence of LHP1, Ring1 and Bmi1 in mosses, lycophytes and monilophytes also suggests the presence of a primitive yet functional PRC1.

59 BASIC BIOLOGICAL SCIENCES↗

DOE OSTI2014

Failure of cap-rock seals as determined from mechanical stratigraphy, stress history, and tensile-failure analysis of exhumed analogs

In this study, the sedimentologic and tectonic histories of clastic cap rocks and their inherent mechanical properties control the nature of permeable fractures within them. The migration of fluid through mm- to cm-scale fracture networks can result in focused fluid flow allowing hydrocarbon production from unconventional reservoirs or compromising the seal integrity of fluid traps. To understand the nature and distribution of subsurface fluid-flow pathways through fracture networks in cap-rock seals we examine four exhumed Paleozoic and Mesozoic seal analogs in Utah. We combine these outcrop analyses with subsidence analysis, paleoloading histories, and rock-strength testing data in modified Mohr–Coulomb–Griffith analyses to evaluate the effects of differential stress and rock type on fracture mode.

58 GEOSCIENCES↗

DOE OSTI2023

Caribbean deepwater snappers: Application of the bomb radiocarbon age estimation validation in understanding aspects of ecology and life history

Reef fishes have been utilized as food fish throughout the U.S. Caribbean and Gulf of Mexico waters for centuries, with increasing fishing effort in recent decades. As a result, many species have experienced declines in landings, including deepwater snappers such as queen snapper Etelis oculatus and blackfin snapper Lutjanus buccanella . However, little to no peer-reviewed published research exists on basic life history parameters for either species. Confirming the accuracy of an age estimation method for a fish species is essential for ensuring sustainable fisheries management. This is because in the assessment of fisheries species population age-based parameters, including longevity, age at sexual maturity, growth rate, mortality, age-specific reproductive output, and lifetime reproductive output, are important in understanding overall life history strategies of managed stocks. The past stock assessment on U.S. Caribbean queen snapper utilized an estimated longevity of 8 y, derived from length frequencies for fish from St. Lucia. Blackfin snapper has an estimated longevity of 27 y based on a relatively small study from offshore waters of the southeastern U.S. The focus of our investigation was to estimate maximum longevity of two data-poor species in the U.S. Caribbean. The accuracy of ageing methods was tested via bomb radiocarbon age estimation validation and effects of depth on Δ 14 C in otolith cores and eye lens core values were examined. Results from our work indicate a maximum validated age of 45 y for queen snapper, and 43 y for blackfin snapper. Our findings indicate queen snapper and blackfin snapper are long-lived (> 40 y). The resulting Δ 14 C comparison between eye lens cores and otolith cores has important implications for the study of age validation, specifically when deepwater species are involved.

59 BASIC BIOLOGICAL SCIENCES↗

DOE OSTI2018

Oxygen Isotope Microanalysis By Secondary Ion Mass Spectrometry Suggests Continuous 300-million-year History of Calcite Cementation and Dolomitization in the Devonian Bakken Formation

Calcite cementation and dolomitization are key diagenetic processes in many sedimentary systems. Unravelling detailed histories and timescales of cementation and replacement is, however, often compromised by the limited spatial resolution of many analytical techniques; in some cases multiple grains are co-analyzed so that diagenetic histories are blurred and reaction periods are difficult to establish. In this study we have used 10-micrometer-resolution, in situ secondary ion mass spectrometry to determine the oxygen isotope composition of 197 individual, 10–50-micrometer-size crystals of dolomite and calcite from six samples in a single core of Upper Devonian middle Bakken Member siltstones and sandstones, the major tight oil formation of the Williston basin, USA. This amount of data places important constraints on the range of temperatures and times that carbonate cementation and replacement occurred. Petrographic data show that microcrystalline calcite cement is an early phase, and combined with mineralogical data suggest that much of the dolomite replaces calcite. Over spatial scales of less than a centimeter, analyses of individual calcite crystals have a range of 5‰ for δ 18 O in the group of crystals, and for the group of individual dolomite crystals, 10‰. These sub-centimeter ranges are as great as those observed in previous studies of carbonate cements sampled over many meters and remind us that previous low-resolution studies may have inadvertently analyzed mixed phases. There is no relationship between dolomite texture and isotopic composition at this spatial scale; microscale backscattered electron imagery and scanning electron microscopy cathodoluminescence zoning is seen, but cannot be resolved with a 10-micrometer spot size. Assuming, since it is an early cement, that calcite precipitated from seawater (δ 18 O = –1.5‰), it formed at ca. 15–40°C, mainly at the lower temperatures. Present-day formation waters in Devonian rocks in this region have oxygen isotope compositions of 7–8‰ VSMOW. Using these values as a likely dolomitizing fluid, we suggest that dolomitization occurred continuously between 40 and 140°C over 150–200 million years, most likely in a fluid with a high Mg/Ca ratio resulting from gypsum formation in local evaporites. Finally, we suggest that this exceptionally low rate of dolomitization was controlled by the low rate of supply of Mg in a very sluggish flow regime; dolomitization is incomplete because of a limited supply of Mg.

58 GEOSCIENCES↗

DOE OSTI2012

The History of Quality in Industry

The quality movement’s long history traces back to the Industrial Revolution and continues through the more modern concepts of Total Quality Management (TQM). This report provides an overview of the history of quality in industry, from its roots through its later movements, including quality inspections, the statistical quality control methods championed by W. Edwards Deming and others, and the influence of Japanese quality management on current American industrial practices.

Kolb, Rachel R.↗

DOE OSTI2012

Statistics of particle time-temperature histories: Progress report for August 2012

Progress toward predictions of the statistics of particle time-temperature histories is presented. The joint statistics of a scalar like the temperature and an exposure time scale are of interest. We have related these quantities to statistics of conserved scalars, their gradients and their diffusive time scales. Future work will apply the one-dimensional turbulence (ODT) model to evaluate the suitability of these statistics to predicting particle time-temperature histories. To that end, we have reported on past performance of the ODT model and have implemented a Lagrangian particle tracking capability into the ODT code. The results of ODT-driven particle dispersion have been compared with classical experimental data, and preliminary statistics of particle evolution in reacting flows are also reported.

Hewson, John C.↗

DOE OSTI2013

History of HERMES III Diode to Z-Pinch Breakthrough and Beyond (learning about Pulsed Power and Z-Pinch ICF)

HERMES III and Z are two flagship accelerators of Sandia s pulsed-power program developed to generate intense ɤ-ray fields for the study of nuclear radiation effects, and to explore high energy-density physics (including the production of intense x-ray fields for Inertia Confinement Fusion [ICF]), respectively. A diode at the exit of HERMES III converts its 20-MeV electron beam into ɤ-rays. In contrast, at the center of Z, a z-pinch is used to convert its 20-MA current into an intense burst of x-rays. Here the history of how the HERMES III diode emerged from theoretical considerations to actual hardware is discussed. Next, the reverse process of how the experimental discovery of wire-array stabilization in a z-pinch, led to a better theory of wire-array implosions and its application to one of the ICF concepts on Z--the DH (Dynamic Hohlraum) is reviewed. Lastly, the report concludes with how the unexpected axial radiation asymmetry measured in the DH is understood. The first discussion illustrates the evolution of physics from theory-to-observation-to-refinement. The second two illustrate the reverse process of observation-to-theory-to-refinement. The histories are discussed through the vehicle of my research at Sandia, illustrating the unique environment Sandia provides for personal growth and development into a scientific leader.

Sanford, Thomas William Lou↗

DOE OSTI2014

Statistics of particle time-temperature histories

Particles in non-isothermal turbulent flow are subject to a stochastic environment that produces a distribution of particle time-temperature histories. This distribution is a function of the dispersion of the non-isothermal (continuous) gas phase and the distribution of particles relative to that gas phase. In this work we extend the one-dimensional turbulence (ODT) model to predict the joint dispersion of a dispersed particle phase and a continuous phase. The ODT model predicts the turbulent evolution of continuous scalar fields with a model for the cascade of fluctuations to smaller scales (the ‘triplet map’) at a rate that is a function of the fully resolved one-dimensional velocity field. Stochastic triplet maps also drive Lagrangian particle dispersion with finite Stokes numbers including inertial and eddy trajectory-crossing effects included. Two distinct approaches to this coupling between triplet maps and particle dispersion are developed and implemented along with a hybrid approach. An ‘instantaneous’ particle displacement model matches the tracer particle limit and provides an accurate description of particle dispersion. A ‘continuous’ particle displacement model translates triplet maps into a continuous velocity field to which particles respond. Particles can alter the turbulence, and modifications to the stochastic rate expression are developed for two-way coupling between particles and the continuous phase. Each aspect of model development is evaluated in canonical flows (homogeneous turbulence, free-shear flows and wall-bounded flows) for which quality measurements are available. ODT simulations of non-isothermal flows provide statistics for particle heating. These simulations show the significance of accurately predicting the joint statistics of particle and fluid dispersion. Inhomogeneous turbulence coupled with the influence of the mean flow fields on particles of varying properties alters particle dispersion. The joint particle-temperature dispersion leads to a distribution of temperature histories predicted by the ODT. Predictions are shown for the lower moments and the full distributions of the particle positions, particle-observed gas temperatures and particle temperatures. An analysis of the time scales affecting particle-temperature interactions covers Lagrangian integral time scales based on temperature autocorrelations, rates of temperature change associated with particle motion relative to the temperature field and rates of diffusional change of temperatures. These latter two time scales have not been investigated previously; they are shown to be strongly intermittent having peaked distributions with long tails. The logarithm of the absolute value of these time scales exhibits a distribution closer to normal.

Hewson, John C.↗

DOE OSTI2020

Of Clouds and Craters: The History of U.S. Nuclear Weapons Testing

“Now!” With that word, the Atomic Age – and the era of nuclear weapons testing – dawned. The advent of World War II’s first irresistible weapon, which had been secretly tested in the New Mexico desert in July 1945, would help hasten the inevitable: complete victory for the Allies. Codenamed Trinity, the test was the first of over a thousand conducted by the United States between 1945 and 1992. Nuclear weapons would change future clashes as well. The looming Cold War, with roots stretching all the way back to 1917, was history’s first conflict between two, major nations armed with nuclear weapons. It is clear the existence of those weapons played an important role in maintaining a tenuous peace between the United States and the Soviet Union; it is also clear nuclear weapons testing played a prominent role in fueling both the arms race and the success of deterrence. Yet, the history of nuclear weapons testing is rarely remembered, even though nuclear tests have been performed in the very recent past. Of the estimated 2,000-plus nuclear tests ever performed, the U.S. is responsible for approximately half. This is the story of U.S. full-scale nuclear weapons testing.

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEF↗

DOE OSTI2020

Uncertainty Propagation from Flux to α and from Time to α in Reaction History

This report documents measurement uncertainty propagation from flux to α and from time to α in gamma reaction history. Analytical formulas are derived, and on the basis of them, their discrete versions are provided to serve for current reaction history software verification, and for development of the future versions of the software. The discrete version is provided for the general case: sparse data with varying time intervals between the data points.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

DOE OSTI2021

Serendipitous discovery connects grandfather and granddaughter at the Lab 60 years apart A third-generation employee learns about Los Alamos family history

The Lab’s enduring mission work means staff like Cameron Townsend are one of many family members who have careers at LANL. Cameron is her family’s third generation to work at the Lab, starting with her great grandparents, followed by her grandparents (skipping her parents), and now including her and her husband. She didn’t know about her family history at the Lab until she started working here three years ago when a typical day on the job became a serendipitous window into her family’s long history with the Lab. Cameron, who is an architect in EPC-ES: Environmental Stewardship and helps manage the Lab’s historic buildings program, was given a drawing from 1960 to aid in an assessment. The drafter’s name on the sketch: Ron Turner, her grandfather.

99 GENERAL AND MISCELLANEOUS↗