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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 1,081 records · Page 60
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Direct Search for Dark Matter

This is the final report for an initial 2-year DOE Office of Science High Energy Physics, Cosmic Frontier grant to the Palladino group at the University of Wisconsin-Madison. Working in the field of direct dark matter detection, the Palladino group is a part of the LUX and LZ collaborations. During this period continued analyses from the LUX experiment were produced, including a world-leading limit to spin-independent interactions of WIMP dark matter. R&D and simulations for the next generation LZ experiment were also completed, primarily at the LZ System test platform at the SLAC National Accelerator Laboratory. The group's work is continued in the grant DE-SC0017647.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2019

LANL Accelerator Activities for C-band

LANL has a range of accelerator activities that would benefit from improvements in RF resonator performance. XFEL (presently using a SRF baseline similar to LCLS-II) would benefit from much higher gradient and long-pulse operation of copper structures. Higher gradient RF structures for lower energy accelerators (~100 MeV) would also provide a path to transportable systems, such as ICS sources. Lastly, the utilization of dielectrics could be exploited for increased efficiency and compactness, e.g. for accelerator in space efforts. A LANL R&D effort aims at systematic improvement of copper structures employing material science simulations to explain and improve breakdown effects, combined with highly optimized designs, integration of cryo-cooling and the use of dielectric insertions. The work is integrated into a High-Gradient collaboration between SLAC, UCLA and LANL.

43 PARTICLE ACCELERATORS↗
DOE OSTI2013

Analysis of Mis-Steered Electron Beam in the NSLS-II Storage Ring

This note reports the analysis of the mis-steered electron in the NSLS-II storage ring for the determination of supplementary shielding. The potential angles and offsets of the mis-steered beam are calculated by implementing the cascaded parameter scan (CPS) along the beam-line. This method is originally developed for the top-off safety analysis, and has been well documented in ref. The basic idea of CPS is to combine the phase space images due to different magnet set-points into one superset, then re-populate virtual particles on a fine grid as the input of the downstream magnet scanning. The purpose of re-population in phase space is to avoid the redundant particle tracking calculation due to the multi-layer overlap of different magnet settings. A parallel python code of implementing the tracking study has been written, and benchmarked with other top-off safety simulators developed in SLAC and LBNL.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Study of Proton Stopping and Energy Deposition in Warm Dense Matter

This grant supported target fabrication and travel costs for Experiment LQ91 at the Matter in Extreme Conditions endstation (MEC) of the SLAC National Accelerator Laboratory’s Linac Coherent Light Source (LCLS). LQ91 was the first experiment to study proton-heated Warm Dense Matter (WDM) with the MEC end station. It was scheduled as the first experiment in MEC following maintenance and upgrades to the optical high intensity laser during LCLS Run 16. The team consisted of scientists, postdocs, and Ph.D. students from UC San Diego and Stanford University divided into two overlapping shifts. The team arrived onsite during the optical intense laser commissioning time to setup and stayed until the end of the experiment culminating in five shifts of awarded LCLS beam time. Postdoc Mathieu Bailly-Grandvaux led preparations in the months leading up to the experiment. During the experiment and in subsequent analysis work, two other UC San Diego postdocs and five UC San Diego graduate students were heavily involved. In this way, the project provided invaluable hands-on training opportunities in high energy-density science for several early-career scientists.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2019

Development of X-Ray FEL Oscillators with Higher Out-Coupling Efficiency

This program focused on the development of high-outcoupling efficiency resonators for x-ray free-electron laser oscillators (XFELOs). The goal was to produce a viable design for an XFELO that can be implemented on the LCLS-II which is the x-ray FEL facility under construction at the Stanford Linear Accelerator Center (SLAC). The program designed at regenerative amplifier (RAFEL) design that employs a high-gain undulator with a low-Q resonator with the goal of producing a scientific design for the RAFEL as well as a software suite that can be used to design XFELOs. The Phase I program considered a resonator consisting of six diamond Bragg reflectors/mirrors with two focusing lenses. This resonator was used in conjunction with the electron beam produced by the LCLS-II and the HXR undulator to design a RAFEL producing 3.05 keV photons in the fundamental resonance and 9.15 keV photons in the 3rd harmonic. The research program included the extension of the Optics Propagation Code (OPC) to describe Bragg reflection from diamond crystal mirrors and went on to use OPC, in conjunction with the MINERVA simulation code to treat the undulator interaction, to simulate the RAFEL. Simulations were conducted in both the steady-state and time-dependent regimes to determine the basic performance characteristics of the RAFEL.

43 PARTICLE ACCELERATORS↗
DOE OSTI2019

Low RF Power Plasma Ignition and Detection for In-Situ Cleaning of 1.3 GHz 9-Cell Cavities

Superconducting Radio Frequency (SRF) cavities performance preservation is crucial, from vertical test to accelerator operation. Field Emission (FE) is still one of the performance limiting factors to overcome and plasma cleaning has been proven successful by the Spallation Neutron Source (SNS), in cleaning field emitters and increasing the work function of Nb. A collaboration has been established between Fermi National Accelerator Laboratory (FNAL), SLAC National Accelerator Lab- oratory and Oak Ridge National Laboratory (ORNL) with the purpose of applying plasma processing to the Linac Coherent Light Source-II (LCLS-II) cavities, in order to minimize and overcome field emission without affecting the high Q of nitrogen-doped cavities. The cleaning for LCLS-II will follow the same plasma composition adopted at SNS, which allows in-situ processing of cavities installed in cryomod-ules from hydrocarbon contaminants. A novel method for plasma ignition has been developed at FNAL: a plasma glow discharge is ignited using high order modes to overcome limitations imposed by the fundamental power coupler, allowing in-situ cleaning for cavities in cryomodule. The plasma can be easily ignited and tuned in each of the cavity cells using low RF power. A method for plasma detection has been developed as well, which allows the detection of the plasma location in the cavity without the need of cameras at both cavity ends. The presented method can be applied to other multi-cell cavity designs, even for accelerators where the coupling for the fundamental modes at room temperature is very weak.

43 PARTICLE ACCELERATORS↗
DOE OSTI2019

A Concept for Ultra-High Energy Electron and Positron Test Beams at Fermilab [PowerPoint]

Experimenters looking for energies higher than 30 GeV will have no current comparable alternatives when CERN test beams are shutdown for 2 years at the end of 2018. Alternate lab electron and positron test beam limits are DESY: Under 10 GeV/c, SLAC: Limited to 25 GeV/c; Fermilab: Ranged from 1 - 32 GeV (highest momenta of ~31.9986 GeV/c) and Mixed Species. A unique opportunity to attract a new group of users has presented itself. As CERN e ± test beams are mixed species, providing higher purity, ultra high energy beams has been requested.

43 PARTICLE ACCELERATORS↗
DOE OSTI2019

Development of Tunable, Precision Permanent Magnet Phase Shifter for X-Ray FEL

In an X-ray free-electron laser (XFEL), a high quality relativistic electron beam from a linear accelerator traverses an array of undulator magnets to generate a high power X-ray beam by allowing the FEL to reach saturation. In many XFELs, phase shifters haven’t been commonly used or included in their designs. The importance of the phase shifter was recognized only recently. A phase shifter can be constructed using either an electromagnet (EM) or a permanent magnet (PM). EM phase shifters are heavy, complex to operate, and take more valuable longitudinal space between the undulators. Compared to EMs, the PMs have several outstanding advantages, including compactness, lighter weights, simple operation, and low maintenance. This project has developed an innovative design of fixed-gap, tunable PM-based compact phase shifter for the XFEL. While keeping the poles and gap fixed, the new design incorporates proven features from the prior work, along with novel field tuning methods, which allow the field strength to be adjusted within a reasonably large range to achieve the desired range of the phase delay control. The PM design without electric currents and power electronics associated with EMs improves reliability by reducing the number of possible points of failure and lowers the operation cost. The compactness makes it possible to use PM phase shifters in the existing XFELs with small gaps between adjacent undulators, as well as in the new XFELs without significantly increasing the FEL length. In Phase I we have accomplished the followings; 1) determined the optimum physics parameters for both weak and strong phase shifters; 2) conducted magnetic design with concrete magnetic and geometrical parameters of actual produced PM materials; 3) provided solutions to achieve precision fine tuning of the magnetic fields with unique methods; 4) elaborated a design based upon ease of manufacturing and cost analysis; and 5) produced rare-earth PM materials, which will be used for prototyping in Phase II. The phase I results provide a foundation for the research and development in the Phase II project, which will aim at building two full-size PM phase shifters and testing at SLAC National Accelerator Laboratory. This project will significantly provide the potential to bring a paradigm change in accelerator technology, replacing conventional electromagnets for many existing accelerator applications and allowing the development of new applications in completely new areas. For example, the PM FEL phase shifters can help significantly improve coherence and power of an XFEL. The proposed use of PM phase shifters will also bring significant cost savings to the construction, operation and maintenance of FEL facilities.

43 PARTICLE ACCELERATORS↗
DOE OSTI2019

Deep inelastic scattering from A = 3 nuclei: Nucleon structure and the EMC effect

The MARATHON experiment ran at Jefferson Laboratory in 2018, measuring deep inelastic scattering of 10.6 GeV electrons from the proton (p), deuterium (D), tritium ( 3 H), and helium-3 ( 3 He). MARATHON's experimental observables are cross section ratios, most notably 3 H/ 3 He. This ratio of mirror nuclei is used for a novel extraction of the nucleon structure function ratio $F^n_2$ /$F^p_2$ with minimal nuclear corrections. Determining leading-order $F^n_2$ /$F^p_2$ at high x provides important constrains on the ratio of nucleon valence quark distributions d/u. The ratios 3 H/D and 3 He/D allow a determination of the EMC effect in the lightest nuclei sensitive to possible isospin dependence of nuclear effects. Lastly, the D/p ratio allows a comparison of the MARATHON experiment to SLAC measurements, and provides data to which the A = 3 ratios can be renormalized. The MARATHON results provide new constraints on d/u. Additionally, the results emphasize the importance of higher-order effects in extracting $F^n_2$ /$F^p_2$ from DIS measurements, and can help constrain said effects. In the renormalization scheme applied in the MARATHON analysis, no significant isospin dependence of the EMC effect is observed.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2019

DOE Data Day 2019 Report

The Department of Energy (DOE) has joined the larger scientific community in the promotion of data management as a means to higher quality, more efficient research and analysis, and as a critical component of data science. Tools and platforms to support data management and analysis are rapidly evolving and provide enormous opportunities. They also pose challenges that can be specific to DOE but are common across DOE mission areas and organizations. The DOE Data Day (D3) workshop was held on September 25–26, 2019, and organized by a team at Lawrence Livermore National Laboratory (LLNL) in an effort to gather the data management practitioners at the DOE labs together to share their work and results, facilitating knowledge transfers and best practices across project teams. Over 100 attendees participated from multiple national labs—LLNL, Sandia (SNL), Lawrence Berkeley (LBNL), Los Alamos (LANL), Oak Ridge (ORNL), Argonne (ANL), Pacific Northwest (PNNL), Stanford Linear Accelerator (SLAC)—along with Mission Support and Test Services (MSTS), National Energy Technology Laboratory (NETL), Pantex, National Security Complex (Y-12), National Nuclear Security Administration (NNSA), the DOE Office of Scientific and Technical Information (OSTI), and elsewhere in the DOE complex.

96 KNOWLEDGE MANAGEMENT AND PRESERVATION↗
DOE OSTI2019

PVMI Bay Area Photovoltaic Consortium (Final Report)

The Bay Area Photovoltaic Consortium (BAPVC) was formed to fund university research on technologies industry will use and thereby investigate new ways for the photovoltaic (PV) industry and university scientists to identify and explore research priorities. Our thesis is that great innovation is more likely stimulated by the collective efforts of manufacturing and academic experts working together rather than direction from either community alone. The consortium is quite effective in promoting the interactions needed to form collaborative teams, often engaging industry members as research participants. All similar university research consortia employ their industry members in advisory capacity. In BAPVC, industry members deliver far more than guidance and advice. They are part of the management team. They review and down select proposals, review projects, and guide the university researchers is setting their research directions. The BAPVC Industry Board holds executive authority over the strategy and operations of the consortium. BAPVC is a consortium led by Stanford University (SU) and University of California at Berkeley (UCB) joined by three leading DOE labs—Lawrence Berkeley National Laboratory, SLAC National Laboratory, and the National Renewable Energy Lab. BAPVC’s success is attributed to its three pillars of support. Three Pillars: (1) Industry sets research agenda, assures relevance, provides path to commercial impact, and contributes funding. (2) Universities and National Labs conduct innovative research and provide workforce development. (3) US Department of Energy provides leadership, support and guidance. Since inception in 2011, BAPVC funded 72 projects involving 26 organizations. Bringing together the differing backgrounds of industry and university participants stimulates innovation. BAPVC’s cultivation of larger collaborative projects among university investigators has also produced notable results. This report will highlight BAPVC contributions in several exciting PV technologies including perovskite/silicon tandem cells, CdTe, reliability and adhesion metrology, ultra-thin silicon cells and application of carrier selective contacts in silicon PV that all owe a portion of their success to cross-consortium collaboration. More importantly, many of the BAPVC-fostered teams have successfully bid for additional support from other sources and continue to expand their productivity. In one case, we report a recent Nature Energy paper published by a team including both university members and two industry members (separate companies) in a collaborative analysis of thin-film tandem cells. Our original proposal set ambitious goals – “BAPVC is composed of the industry members and prestigious universities needed to add substantial value to the open and competitive process of providing universities all over the nation with funding to perform industry-relevant R&D…Our consortium will accelerate the coordination of stakeholders across the solar industry and academic sectors into a cohesive research force developing innovative solutions to the key industrial issues.” While the PV landscape has undergone vast change during the period of this award, BAPVC and its research and industry members have adapted, delivering the promised cohesive research force for the benefit of DOE and the public.

14 SOLAR ENERGY↗
DOE OSTI2020

Plasma Processing to Mitigate Field Emission in LCLS-II 1.3 GHz SRF Cavities

A collaboration between Fermilab, SLAC and ORNL is working to develop plasma processing for 1.3GHz TESLA shaped SRF cavities. Hydrocarbon (C x H y ) contaminations and adsorbates lower the cavity surface work function (Φ) increasing Field Emission (FE). Plasma processing removes C x H y allowing the cavity to operate at higher E acc .

43 PARTICLE ACCELERATORS↗
DOE OSTI2020

Cryomodules for LCLS-II High Energy

1.3 GHz cryomodules for LCLS-II High Energy (HE) at SLAC will utilize the proven design from LCLS-II. There will be a number of small changes to capture the as-built design for LCLS-II and optimize assembly, but the overall design concept is the same.

43 PARTICLE ACCELERATORS↗
DOE OSTI2020

PPPL Engineering Review - Systems Subcommittee Report

Sandia and SLAC staff evaluated Princeton Plasma Physics Laboratory (PPPL) engineering procedures. The report documents, team members, interviewees and documents consulted, lines of inquiry, strengths and best practices, weaknesses and risks, opportunities for improvement, and general comments.

42 ENGINEERING↗
DOE OSTI2016

Report of the Basic Energy Sciences Workshop on the Future of Electron Sources, September 8-9, 2016

Electron sources represent an enabling technology for all cutting-edge applications of electron accelerators, two of the most notable ones being the X-ray free electron laser (FEL) and the electron microscope. FELs were enabled by the development of high-brightness electron sources, and they have changed the paradigm for a broad spectrum of scientific research. Electron microscopes have achieved sub-Å spatial resolution through the introduction of a cold field-emitter and aberration correction optics. Further development of these tools to atomic spatial and temporal resolutions is needed to advance atomic and molecular sciences to new levels of precision. Though the field of electron sources is quite mature, both revolutionary and evolutionary advances in electron sources are needed. On September 8-9, 2016, BES sponsored a Workshop on the Future of the Electron Source at SLAC National Accelerator Laboratory. The goal of the workshop was to define the electron source requirements for future XFELs, UED and UEM, and to identify future research and development (R&D) opportunities. More than sixty participants from U.S. national laboratories, academia, and international institutions attended the workshop. The workshop started with four plenary talks covering the status of electron sources, and highlighting the most urgent needs of future X-ray and electron scattering facilities. The talks made it evident that significant progress in electron sources will not only maximize the impact of current facilities, but also enable novel capabilities that can help maintain the U.S. leadership in X-ray and electron-based scattering instrumentation. Four breakout panels addressed the major technical areas of electron sources: (1) science and technology of electron generation, (2) continuous wave (CW) electron sources, (3) pulsed electron sources, and (4) exotic electron sources. Prior to the workshop, the panel co-chairs polled the panelists and other experts in the field and invited them to make recommendations on the most promising ways to advance the field of electron sources. During the workshop, each panel reviewed the proposals and novel ideas submitted. These summaries of the discussions on scientific needs and instrument requirements and their recommendations form the basis of this report.

43 PARTICLE ACCELERATORS↗
DOE OSTI2019

Precision Measurement of the Proton Magnetic Form Factor at High Q2

Elastic electromagnetic form factors characterize the distribution of electric charge and magnetization current inside the nucleon and reflect the internal structure determined by Quantum Chromodynamics. Existing data on the proton magnetic form factor at high Q2 (the 4-momentum transfer squared) have large statistical and systematic uncertainties. The GMp experiment E12-07-108 was one of the first set of experiments to run in Hall A at Jefferson Lab after the 12 GeV upgrade with the goal of this experiment to precisely measure the electron-proton elastic cross section for Q2 up to 17 GeV2 with an accuracy of better than 2% - several times better than existing data in this Q2 range. This will allow further tests of form factor scaling predicted by pQCD and, additionally, will be an important benchmark for many other experiments where elastic electron-proton scattering is used for normalization. Since, GMp data were taken at lower ?(virtual photon polarization) than SLAC data, the measured cross sections recieve a smaller contribution from the electric form factor. This dissertation analyzed the GMp experiment data for five different kinematic settings determining the form factor with total uncertainties nearly two times smaller than the existing data at these Q2. This dissertation also presents the results of all Fall 2016 and Spring 2016 GMp experiment data. The proton magnetic form factors were extracted using both the Rosenbluth separation method and a parameterization of the form factor ratio (?pGpE=GpM) obtained from a fit to the existing cross section data. At the end of this thesis, the extracted GMp form factor data is compared to the existing data. The results for ?pGpE=GpM from Rosenbluth separations are found to be consistent with previous extractions, but with significantly reduced uncertainties, further highlighting the discrepancy with the polarization transfer technique. This data set can provide significant additional constraints on contributions from two-photon exchange.

Narayan Gautam, Thir↗