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At least 667 records · Page 37

Milestone in predicting core plasma turbulence: successful multi-channel validation of the gyrokinetic code GENE

On the basis of several recent breakthroughs in fusion research, many activities have been launched around the world to develop fusion power plants on the fastest possible time scale. In this context, high-fidelity simulations of the plasma behavior on large supercomputers provide one of the main pathways to accelerating progress by guiding crucial design decisions. When it comes to determining the energy confinement time of a magnetic confinement fusion device, which is a key quantity of interest, gyrokinetic turbulence simulations are considered the approach of choice – but the question, whether they are really able to reliably predict the plasma behavior is still open. The present study addresses this important issue by means of careful comparisons between state-of-the-art gyrokinetic turbulence simulations with the GENE code and experimental observations in the ASDEX Upgrade tokamak for an unprecedented number of simultaneous plasma observables.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

ZnO quantum dot–molecule conjugates: Chemical interactions, charge dynamics, and spin polarization

Conjugates between molecules and quantum dots (QDs) have been explored for a range of potential applications from photocatalysis and photovoltaics to quantum information science technologies. A particularly ubiquitous material in many of these applications are ZnO QDs since they can accept and transport electrons and can also act as hosts for unique spin states. Conjugates between molecular light absorbers and ZnO QDs have been explored for decades as components in dye-sensitized solar cells. Recently, these materials have also attracted interest for their ability to produce spin-polarized states upon photoexcitation. The current paper employs a series of light absorbing perylene molecules with different ZnO QD sizes to explore key features of these QD–molecule conjugates: (1) chemical interactions, (2) charge dynamics, and (3) spin polarization. The chemical interactions between the molecules and QDs are determined with binding equilibria and reveal dramatic impact of ligand size. The charge transfer dynamics from photoexcited perylenes to ZnO QDs were found to depend exponentially on the linker length. Finally, time-resolved electron paramagnetic resonance experiments reveal that these conjugates generate spin-polarized states in the form of radical pairs and triplets. These spin states hold promise as potential qubits and also offer an avenue to efficiently sensitize molecular triplets.

Hernandez, Frida S. [Amherst College, MA (United S↗

Equity for women and underrepresented minorities in STEM: Graduate experiences and career plans in chemistry

Significance On June 10, 2020, as part of the Black Lives Matter movement, scientists in the United States and throughout the world paused to consider how systematic racism affects the scientific enterprise. As a result, many academic departments are now assessing policies and practices that may contribute to this situation. This paper provides evidence of the nature of inequities related to race–ethnicity and gender in graduate school experiences and career plans of PhD students in one science, technology, engineering, and math (STEM) discipline, chemistry. The results can help promote understanding of the problems and guide efforts toward equity within STEM and, potentially, other academic areas. In turn, these changes can strengthen the scientific enterprise and the well-being of society.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

A Survey: Handling Irregularities in Neural Network Acceleration with FPGAs

In the last decade, Artificial Intelligence (AI) through Deep Neural Networks (DNNs) has penetrated virtually every aspect of science, technology, and business. Many types of DNNs have been and continue to be developed, including Convolutional Neural Networks (CNNs), Recurrent Neural Net- works (RNNs), and Graph Neural Networks (GNNs). The overall problem for all of these Neural Networks (NNs) is that their target applications generally pose stringent constraints on latency and throughput, while also having strict accuracy requirements. There have been many previous efforts in creating hardware to accelerate NNs. The problem designers face is that optimal NN models typically have significant irregularities, making them hardware-unfriendly. In this paper, we first define the problems in NN acceleration by characterizing common irregularities in NN processing into 4 types; then we summarize the existing works that handle the four types of irregularities efficiently using hardware, especially FPGAs; finally, we provide a new vision of next-generation FPGA-based NN acceleration: that the emerging heterogeneity in the next-generation FPGAs is the key to achieving higher performance.

Geng, Tong↗

Experiments and Project-Based Enhancements for STEM Learning

Motivating K-12 students to pursue careers in science, technology, engineering, and mathematics (STEM) is an effort that requires consistent engagement. Throughout the K-12 student timeline, STEM educators need to continuously pivot their teaching and update their educational materials to motivate the next generation of students. Once students begin their undergraduate education, university professors need to encourage them to consider pursuing graduate studies to ensure that a qualified future workforce can be developed for research and teaching. In this paper, we present our work on developing STEM materials for K-12 student engagement. Our K-12 materials target the grid integration of hydrogen assets that are suitable to engage students in the classroom. Our undergraduate materials target hands-on projects and collaboration with industry to connect classroom learning with real-world applications and needs in renewable energy. Our work leverages available open-source models and tools to create projects for undergraduate students and motivate their interest in pursuing research topics in graduate-level education.

ENERGY PLANNING, POLICY, AND ECONOMY↗

“When I talk about it, my eyes light up!” Impacts of a national laboratory internship on community college student success

Participation in technical/research internships may improve undergraduate graduation rates and persistence in science, technology, engineering, and mathematics (STEM), yet little is known about the benefits of these activities a) for community college students, b) when hosted by national laboratories, and c) beyond the first few years after the internship. We applied Social Cognitive Career Theory (SCCT) to investigate alumni perspectives about how CCI at Lawrence Berkeley National Laboratory (LBNL) impacted their academic/career activities. We learned that alumni had low confidence and expectations of success in STEM as community college students. Participation in CCI increased their professional networks, expectations of success, and STEM skills, identity, and self-efficacy/confidence. Hispanic/Latinx alumni recalled the positive impact of mentors who prioritized personal connections, and women valued "warm" social environments. We propose several additions to the SCCT model, to better reflect the supports and barriers to STEM persistence for community college students.

careers↗

SubTER ZTEM (Z-Axis Tipper Electromagnetic) Survey Results, Mineral Mountains Area, Utah

This data was acquired as part of the Subsurface Science, Technology and Engineering Research, and Development (SubTER) Crosscut which is a collaboration across the Department of Energy offices involved in research activities in energy production/extraction, subsurface storage, and environmental remediation. The contents of this zip contains the ZTEM survey measured and processed results for the Mineral Mountains area, Utah. The data were acquired through subcontract to Geotech Inc of Aurora, ON, Canada and their narrative report is included. There are also two readme.txt file included that further describe the data.

15 GEOTHERMAL ENERGY↗

News and Notes: SSA Task Force on Diversity, Equity, and Inclusion: Toward a Changing, Inclusive Future in Earthquake Science

In the United States, a wide variety of studies show that the geoscience community does not reflect the broader societal makeup (e.g., Velasco and Jaurrieta de Velasco, 2010; Dutt, 2020; Howley, 2020). In fact, only about 10% of all Science, Technology, Engineering, Mathematics (STEM) Ph.D. degrees are awarded to people of color, although they represent more than a third of the population (Dutt, 2020). These numbers have changed little over the past 40 years (e.g., Bernard and Cooperdock, 2018; Dutt, 2020). Recent events in the United States have again raised awareness of this discrepancy in many fields; similar divergences may be present throughout the world. How this discrepancy represents a tremendous loss of talent and contributes to ongoing bias and racism is discussed.

58 GEOSCIENCES↗

Board 160: Empowerment in STEM Day: Introducing High School Girls to Careers at National Laboratories (Work in Progress)

In the US, women are still vastly underrepresented in STEM (science, technology, engineering, and mathematics) careers, and various studies have shown that girls' interest in STEM careers wane as high school progresses. With this challenge in mind, Empowerment in STEM Day was organized by Lawrence Berkeley National Laboratory (LBNL), hosting 47 high school students from 6 public high schools in the area. This one-day event was designed and executed through a collaboration between the Women's Support and Empowerment Council (WSEC) and the K-12 STEM Education and Outreach Program at LBNL. The main goal of this program was to provide high school girls, who have little access to STEM career role-models in their immediate surroundings with insights into how a career in STEM looks like. Invitations to participate in the program were sent out to six local high schools in the Bay area asking educators to identify female students that were interested in STEM. Each high school participant was provided with an opportunity to experience a national laboratory environment, learn more about summer workshops and paid summer research internship opportunities at LBNL for high school students, and engage directly with LBNL's employees through job shadow, career mapping and speed networking sessions. In this paper, we will present an overview of the event organization, challenges faced during planning and execution of the event, discuss the lessons learned from the first Empowerment in STEM Day and suggest strategies for incorporating such events at other national laboratories and academic institutions as part of a vital effort into recruiting and retaining more high school girls in STEM-based careers. Additionally, since this was the first in-person event hosted by LBNL's K-12 Program after the pandemic, we will also share the strategies implemented at the event so as to engage both remote and on-site employees as volunteers.

Bose, Baishakhi↗

Coupling between TOUGH3 and FLAC3D

Sandia National Laboratories has hired Itasca Consulting Group, Inc., the authors of the FLAC3D geomechanics software, to couple FLAC3D with TOUGH3, the porous media flow solver. The work is being done to enable a coupled mechanical-thermal-hydraulic analysis of a potential criticality event in a dual purpose cannister (DPC). The U.S. Department of Energy Office of Spent Fuel and Waste Science & Technology is investigating the performance of DPCs for direct geological disposal of spent nuclear fuel. Post closure criticality control is an important aspect of this investigation. Over geological timescales, it is envisioned that the canister and canister overpack will develop fractures due to stress corrosion processes. A breach in the canister could allow groundwater to fill the canister. Fresh water is a neutron moderator; thus, if the canister internals and fuel assemblies have been sufficiently degraded, a criticality event could occur. Such an event would release enough energy to boil the water between the fuel rods and pressurize the cannister. This internal pressurization may cause the initial fractures in the canister and overpack to grow. It is important to understand the change in hydraulic transmissivity between the canister and surroundings for two reasons: first, because it may control the potential for and frequency of subsequent criticality events; second, because it will control the release of radionuclides from the canister. The motivation for this work is to better understand the potential for periodic criticality events, cannister damage, and release of radionuclides during a criticality event in a DPC.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

LANL Overview Summer 2020 [Slides]

This presentation provides an overview of the lab, the organization, operations and mission, and the six key areas of science technology and engineering. Next, the presentation provides a picture of employment at LANL and gives advice for exploring opportunities for both collaboration and employment.

96 KNOWLEDGE MANAGEMENT AND PRESERVATION↗

International Collaborations on Radioactive Waste Disposal in Salt (FY20)

This report is a summary of the international collaboration work conducted by Sandia and funded by the US Department of Energy Office (DOE) of Nuclear Energy Spent Fuel and Waste Science & Technology (SFWST) as part of the Sandia National Laboratories Salt R&D and Salt International work packages. This report satisfies milestone level-three milestone M3SF-205N010303062. Several stand-alone sections make up this summary report, each completed by the participants. The first two sections discuss international collaborations on geomechanical benchmarking exercises (WEIMOS), granular salt reconsolidation (KOMPASS), engineered barriers (RANGERS), and documentation of Features, Events, and Processes (FEPs).

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Los Alamos National Laboratory Release of Cesium-137 Corrective Action Plan

This Corrective Action Plan (CAP) was developed by a team chartered by John Sarrao, Deputy Director for Science, Technology, and Engineering (DDSTE), to review and respond to the findings of the Joint National Nuclear Security Administration/Triad National Security (NNSA/Triad) Investigation Team (JIT) Joint Investigation Report for the “Sealed Source Recovery at the University of Washington Harborview Training and Research Facility Results in Release of Cesium-137 on May 2, 2019,” dated March 30, 2020. On May 2, 2019, International Isotopes, Inc. (INIS), a subcontractor to Triad National Security, LLC, inadvertently breached a sealed cesium-137 source at the University of Washington (UW), Harborview Medical Center Research and Training (HRT) building in downtown Seattle while attempting to recover the source for the National Nuclear Security Administration (NNSA) Off-Site Source Recovery Program (OSRP). The source breach resulted in contamination of personnel and the HRT building, as well as a release of radioactive material to the environment

07 ISOTOPE AND RADIATION SOURCES↗

M4SF-20LL010301082-Sorption Database and Model for Generic Disposal System Assessment

This progress report (Level 4 Milestone Number M4SF-20LL010301082) summarizes research conducted at Lawrence Livermore National Laboratory (LLNL) within the Argillite International Collaborations Activity Number Activity SF-20LL010301081. The activity is focused on our long-term commitment to engaging our partners in international nuclear waste repository research. The focus of this milestone is surface complexation model international collaborations. Specifically, we are developing a database framework for Spent Fuel and Waste and Science Technology (SFWST) that is aligned with the Helmholtz Zentrum Dresden Rossendorf (HZDR) sorption database development group in support of the database needs of the SFWST program.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

M4SF-20LL010301042: Updated Thermodynamic Database for Use in Generic Disposal System Assessment

This progress report (Level 4 Milestone Number M4SF-20LL010301042) summarizes research conducted at Lawrence Livermore National Laboratory (LLNL) within the Argillite Activity Number SF-20LL010301041. LLNL is leading efforts in the development of thermodynamic databases in support of the Spent Fuel and Waste Science Technology (SFWST) program. Thermodynamic models provide the basis for understanding the stability of solid phases and speciation of aqueous species and modeling the evolution of repository conditions. The LLNL effort is being performed in coordination with other US database development efforts. The effort includes a review of available thermochemical databases and a path forward for database integration. International coordination with the NEA-TDB is supported through crystalline international work package.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

FY20 Update on Brine Availability Test in Salt. Revision 4

This report summarizes the 2020 fiscal year (FY20) status of the borehole heater test in salt funded by the US Department of Energy Office of Nuclear Energy (DOE-NE) Spent Fuel and Waste Science & Technology (SFWST) campaign. This report satisfies SFWST level-two milestone number M2SF-20SNO10303032. This report is an update of an August 2019 level-three milestone report to present the final as-built description of the test and the first phase of operational data (BATS la, January to March 2020) from the Brine Availability Test in Salt (BATS) field test.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Integrated Initiative for Plutonium and Actinide Missions

Recognizing the dynamic environment and challenges facing the plutonium and actinide missions at Los Alamos National Laboratory over the next decade, Laboratory leadership established Fiscal Year (FY) 2020 Laboratory Agenda Item 2.6. This agenda item calls for the development and implementation of an integrated initiative for plutonium and actinide missions at Los Alamos. Over the next decade, Los Alamos has been asked to significantly ramp up pit production to help address nuclear stockpile and nuclear deterrence needs, heat source production to support expansion in space exploration, evaluation of stockpile returns, processing operations in support of nonproliferation, and the actinide science to support all of these efforts. All of this must be accomplished while significantly increasing the size of our plutonium and actinide missions workforce and modernizing and updating critical infrastructure. Only through enhanced integration of science, technology, and engineering (ST&E), manufacturing, and mission operations will we enable achievement of these critical missions. An overall summary of the plutonium and actinide missions is included in Figure 1 on Page 3 and Figure 2 on Page 4 summarizes our goals, objectives, FY 2021 recommended actions and internal strategic priorities that are key elements of our integrated initiative.

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEF↗

Science Resource Office Peer Review and Metrics Factsheet [Slides]

The Science Resource Office-Peer Review and Metrics (SRO-PRM) Team hosts and maintains LANL's central repository for Science, Technology, and Engineering (STE) data. The Team tracks, integrates, analyzes, and reports qualitative and quantitative data measuring performance, quality, impact, and productivity. These metrics are indicators of the effectiveness and impact of STE efforts.

96 KNOWLEDGE MANAGEMENT AND PRESERVATION↗