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At least 1,135 records · Page 63

The Trinity High Explosive Implosion System: The Foundation for Precision Explosive Applications

This article is set during the 1944 and 1945 final push to complete Project Y—the Manhattan Project at Los Alamos—and focuses primarily on overcoming the challenge of creating and demonstrating a successful convergent explosive implosion to turn a subcritical quantity of plutonium into a critical mass. The critical mass would then efficiently yield kilotons of trinitrotoluene (TNT)-equivalent energy in about a microsecond, demonstrating the implosion atomic bomb concept. This work culminated in the Trinity atomic test near Alamogordo on July 16, 1945. This implosion effect demarcated the approach to explosive science and technology the Laboratory has followed ever since, including development of high-explosive synthesis and formulation, small and large test and diagnostic facilities, shock dynamics theory, high-explosive system design engineering, and three-dimensional implosion modeling and simulation using some of the fastest computers in the world. This work also ushered in a period of broader application of precision high explosives in conventional munitions, demolition, mining and oil exploration, and space travel.

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEF↗

Institutional Computing: Annual Progress Report, Precision early universe simulations to constrain nuclear reactions and beyond standard model physics

The current one-year allocation (w20 qburst) is the first year in a two year allocation of the same name. The project has supported two publications in peer-review journals, another manuscript in preparation for publication, a white paper for the Astro2020 Decadal Survey, and a number of talks (see below). Code development continues on implementing a neutrino quantum kinetic equation solver into BURST, now called QBURST. While implementing coherent and forward-scattering processes into the dynamical neutrino evolution equations, multiple numerical issues have appeared. We have remedied a number of these issues through extensive debugging and testing, which include streamlining interpolation and implementing new ODE integration techniques. Further testing is required to solve the problem at a precision of better than one part in 10 6 . We expect that we will understand the numerical difficulties and implement solutions by end of year 2021.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

Variable Precision Computing (VPC) (Final Report)

The overall goal of the Variable Precision Computing project is exploring and identifying ways to reduce internodal communication cost in production physics simulation experiments running on a distributed-memory systems by compressing data, either in a lossy or lossless way, thus resulting in a significant computational performance increase. Among the several approaches proposed, the one discussed here has been proposed, designed and implemented by me. It concerns the application of information theory-derived metrics to classical molecular dynamics and computational fluid dynamics simulation experiments.

97 MATHEMATICS AND COMPUTING↗

Mixed Precision Numerical Linear Algebra (Final Report)

The objective of this subcontract was to identify opportunities for the use of mixed precision within iterative solvers and to explore these opportunities both theoretically and experimentally. All quarterly milestones were achieved. We summarize the achievements each quarter in sections below.

97 MATHEMATICS AND COMPUTING↗

Precision Electroweak and QCD Studies with Polarized Electrons (Final Technical Report)

In this final technical report, we report on the main products from the scope of the work of the award, in particular the Ph.D. dissertations that summarize the work done by the three graduate students who completed their requirements and defenses during calendar 2021, after completing data analyses on the PREX-II and CREX experiments which made precision measurements of neutron RMS radii of 208 Pb and 48 Ca nuclei.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

Workshop on Ultra-Precision Control for Ultra-Efficient Devices (Workshop Report)

On April 21–23, the U.S. Department of Energy’s (DOE’s) Advanced Manufacturing Office (AMO) within the office of Energy Efficiency and Renewable Energy (EERE) held the second in a series of workshops on different topics related to semiconductor research and development (R&D) to increase energy efficiency. This workshop focused on ultra-energy-efficient devices and the ultra-precision manufacturing (UPM) processes and next-generation control and metrology technologies needed to manufacture these devices. In addition to the industry needs and RDD&D opportunities, AMO’s new goal on greenhouse gas (GHG) reduction was addressed. The output of this workshop will inform AMO’s future R&D portfolio investments; provide perspectives on trends, drivers, and challenges for ultra-energy-efficient devices and enabling technologies; and help the stakeholder community understand the opportunities on the horizon.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Energy-Energy Correlators for Precision QCD

In this contribution to the Proceedings of the US Community Study on the Future of Particle Physics (Snowmass 2021) we review recent progress in the evaluation and application of the Energy-Energy Correlator (EEC) event shape observable in $e^+e^⁻$ annihilation, hadronic collisions, and deep inelastic scattering. The importance of EEC as a precision probe of the perturbative and non perturbative aspects of QCD dynamics is emphasized. It can be used to extract the strong coupling constant and to constrain TMD distribution functions. Closely related energy-correlation shape variables have also been used to tag boosted objects produced in high energy collisions. The opportunities to study EEC at the future Electron-Ion Collider are also highlighted.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

High Precision Penning Trap Measurements of beta-decay Q-values for Neutrino Physics

The 2015 Nobel Prize in physics was awarded to Takaaki Kajita and Arthur B. McDonald “for the discovery of neutrino oscillations, which shows that neutrinos have mass”. This fact has wide reaching implications for the standard model of particle physics, nuclear physics, and cosmology. However, important fundamental questions remain: What is the absolute neutrino mass scale? Is the neutrino a Majorana or a Dirac particle? A number of large-scale experiments are underway or are being developed to attempt to answer these questions. Two classes of experiments are direct neutrino mass determination experiments, and searches for neutrinoless double betadecay. This work aimed to aid these experiments via high-precision Q value determinations for the relevant isotopes using Penning trap mass spectrometry (PTMS).

42 ENGINEERING↗

Mixed Precision Numerical Linear Algebra (Final Report)

The objective of this subcontract was to identify opportunities for the use of mixed precision within iterative solvers and to explore these opportunities both theoretically and experimentally. All quarterly milestones were achieved. We summarize the achievements each quarter in this report.

97 MATHEMATICS AND COMPUTING↗

Specification of EBR-II Gamma Scan Data from the Precision Gamma Scanner

The gamma scan data stored in the FIPD was originally measured using the Precision Gamma Scanner (PGS) at the Hot Fuel Examination Facility (HFEF) at Idaho National Laboratory (INL). This system was originally manufactured in 1971 (when the facilities, now at INL, were operated by Argonne National Laboratory) and was upgraded on several occasions. It consists of a germanium gamma ray detector (the exact nature of which changed over time as technology improved), a variable-slit collimator that blocks the view of gamma emissions from all but the selected area of the target, and a computer-controlled system for translating a sample past the slit and logging the data.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Precision Measurement of the Eta Radiative Decay Width via the Primakoff Effect with GlueX

The GlueX detector in the experimental Hall-D at Jefferson Lab provides a unique capability to perform a measurement of the eta to gamma gamma decay width via the Primakoff effect with the precision significantly better than all existing collider and Primakoff results. The experiment will measure differential cross sections of eta mesons at forward angles on a liquid hydrogen and helium targets using a beam of tagged photons, which will be used for the extraction of the decay width. The measurement is essential for the determination of the fundamental properties such as the ratios of the light quark masses and the eta eta-prime mixing angle, and will provide an important test of chiral symmetry breaking in QCD. The experimental results will also allow to significantly reduce uncertainties on partial widths of all other eta decays. We will give an overview the PrimEx-D physics program and experimental setup.

Somov, Alexander↗

SoW for KDP Precision Cleaning System Control Sys Refurbishment

The KDP Optic Precision Cleaning System (PCS) is used is a standalone batch-process system used to clean Potassium di-Hydrogen Phosphate (KDP) optics required for the National Ignition Facility (NIF). There are two nearly identical machines owned by the US government, as provided by Lawrence Livermore National Security (LLNS). One machine is located at Lawrence Livermore National Laboratory in Livermore, CA in a Class 100 cleanroom and the other is located at the Gooch & Housego (G&H) facility in Highland Heights, OH in a Class 1,000 cleanroom.

42 ENGINEERING↗

Mixed Precision Numerical Linear Algebra (Final Report)

The objective of this subcontract was to identify opportunities for the use of mixed precision within iterative solvers and to explore these opportunities both theoretically and experimentally. All quarterly milestones were achieved. Quarterly achievements are summarized in sections.

97 MATHEMATICS AND COMPUTING↗

High-Performance Electron Sources: Numerical Methods and Beam Dynamics at the Precision Frontier

Electron sources have a wide range of applications and there are many stakeholders that express continuing need for improvements and performance enhancements. Whether we consider ultra-cold, high-brightness, high-charge or high-average current source needs, there are some common themes from the point of view of the beam dynamics involved. These are the following ones: ability to model accurately the emission processes, including the presence of often complicated cathode and other boundary surfaces with a wide range of spatial scales; ability to deal accurately and efficiently with a large number of particles interacting pair-wise, including the stochastic part of these interactions with a wide range of spatial scales; and ability to propagate the particle distributions in time, including collisions with a wide range of temporal scales. These tasks require high precision and accuracy since the goal is usually generation, transport and preservation of very high-quality beams. This grant addressed one of the rem

43 PARTICLE ACCELERATORS↗

Mixed Precision Numerical Linear Algebra (Final Report)

The objective of this subcontract was to identify opportunities for the use of mixed precision within iterative solvers and to explore these opportunities both theoretically and experimentally. All quarterly milestones were achieved. We summarize the achievements each quarter in sections below.

97 MATHEMATICS AND COMPUTING↗

Novel Signatures Beyond the Standard Model: From Extreme Environments to Precision Measurements

Most of our universe is dark. It is dark literally—visible matter makes up only 5% of the energy density—and conceptually, as many outstanding questions remain unsolved. The discovery of particle dark matter would shed light on our dark universe and throw open a window on the highest energy scales. This research made progress toward dark matter and new particle searches in three ways. Extreme compact objects, such as black holes, neutron stars, and stellar cores, can parametrically increase the production rates of feebly interacting particles and yield observable signatures. Specifically, a process known as superradiance leads to exponential growth of the number of ultralight particles gravitationally bound to rotating black holes, and turns astrophysical black holes into particle detectors. This research broadened the scope of applicability of superradiance studies to particles with a wide range of interactions and masses, predicting multi messenger signals. When ultralight particles are produced as dark matter in the early universe, they can be detected directly in laboratory experiments. However, these feebly interacting particles lead to small signals that are inevitably difficult to tease out from backgrounds; their detection requires the theoretical development of unique signatures that can be searched for in low-noise experiments. Some dark matter particles could be detectable with thin film metamaterials combined with low noise single-photon detectors. This research develop the theoretical framework and supported experimental efforts for ambitious searches for a wider class of ultralight particles. Overall, the outcome of this theoretical particle physics program developed novel signatures of new dark matter particles, and thereby expanded the particle parameter space which can be explored with astrophysical observations and precision experiments.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗