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Results and Limits of Time-Division Multiplexing for the BICEP Array High-Frequency Receivers

Time-division multiplexing is the readout architecture of choice for many ground and space experiments, as it is a very mature technology with proven outstanding low-frequency noise stability, which represents a central challenge in multiplexing. Once fully populated, each of the two BICEP Array high-frequency receivers, observing at 150 GHz and 220/270 GHz, will have 7776 TES detectors tiled on the focal plane. The constraints set by these two receivers required a redesign of the warm readout electronics. The new version of the standard multichannel electronics, developed and built at the University of British Columbia, is presented here for the first time. BICEP Array operates time-division multiplexing readout technology to the limits of its capabilities in terms of multiplexing rate, noise and cross talk, and applies them in rigorously demanding scientific application requiring extreme noise performance and systematic error control. Finally, future experiments like CMB-S4 plan to use TES bolometers with time-division/SQUID-based readout for an even larger number of detectors.

47 OTHER INSTRUMENTATION↗

Alloy 625 Qualification Pathway for ASME Section III Division 5 Class A construction

The American Society of Mechanical Engineers Boiler and Pressure Vessel Code Section III Division 5 provides construction and inspection rules to ensure the safety of nuclear components operating at elevated temperatures, defined as those operating above 700°F (370°C) or 800°F (425°C), depending on the material type. At present, there are six materials approved for Class A (high safety significance) component construction under ASME BPVC Section III Division 5. Out of these six materials, five materials are steels or iron-based alloys and one material, Alloy 617, is a nickel alloy. Nickel alloys are stronger than steels; however, Alloy 617 consists of 10-15% cobalt, and activation is a concern under irradiation. Therefore, there is a need to qualify new nickel alloy with lower cobalt content. Alloy 625 is one candidate which has similar mechanical properties at elevated temperature compared to Alloy 617 and has a maximum of 1% cobalt. Although Alloy 625 material properties have been developed in the past to support allowable stress development under ASME Section II, new test results would be needed to qualify this material for elevated temperature component construction under ASME Section III Division 5. The purpose of this report is to describe a path towards developing a Nuclear Code Case to qualify Alloy 625 (UNS N06625; Grade 1 and Grade 2) for elevated temperature nuclear use in accordance with the ASME BPVC rules. This report reviews the existing database on Alloy 625, presents proposed test campaign, and discusses potential paths for accelerating the accelerated material qualification process.

36 - MATERIALS SCIENCE↗

Current divisions and distributed Joule heating of two-dimensional grid microstructures

This work presents current divisions and distributed Joule heating of two-dimensional (2D) grid microstructures. The current divisions on 2×2, 4×4, and n×n grid microstructures made of the same conductive beams are analyzed theoretically, and Kirchhoff's voltage law (KVL) and Kirchhoff's current law (KCL) are employed to determine the current division factors and directions under different voltage input cases. The equivalent resistances and Joule heating power are therefore derived. 2D 2×2 grid microstructures made of gold (60 nm in thickness) and those made of near-equiatomic NiTi (850 nm in thickness) for various independent voltage input cases are fabricated by electron-beam evaporation and co-sputtering, respectively. The equivalent resistances of these grid microstructures are measured by four-terminal resistance measurement at ambient conditions, which show a good agreement with the theoretical results. Further investigation on the electrical resistivities of evaporated gold layer (4.85 × 10 -8 Ω ∙ m) and co-sputtered NiTi (1.23 × 10 -5 Ω ∙ m) reveals that the influences of scale effect and fabrication process on the resistivity cannot be neglected. As such, it is found to be necessary to consider the materials' resistivity in the fabricated grid microstructures before their electro-thermal analysis.

25 ENERGY STORAGE↗

Physics Division Strategic Plan Fiscal Years 2020-2024

The vision of the Physics Division (PHY) at Argonne National Laboratory is to continue enhancing its role as a world-leading institution in basic nuclear physics research and its applications. Key to this vision is for PHY to continue to safely and effectively operate and evolve the capabilities of the Argonne Tandem Linac Accelerator System (ATLAS) facility to best serve its users. ATLAS is the Department of Energy (DOE) accelerator facility for low-energy nuclear physics research. The research carried out by PHY covers many themes in contemporary science but can be distilled into five areas of focus. These themes are interconnected, with continuously evolving synergies between the various groups and facilities in PHY and the broader Laboratory. This five-year strategic plan serves to illustrate our current capabilities and new directions related to these five areas of focus (ATLAS also develops an independent strategic plan): Accelerator research and design. The goal of this theme is to design, fabricate, test, and implement novel accelerator systems, with a focus on high-intensity ion and electron systems. These R&D activities have led to enhancements in the ATLAS accelerator system. Among others, the division’s accelerator systems are in use or planned for use at Fermilab, the Advanced Photon Source, and in a broad variety of applications at the Facility for Rare Isotope Beams (FRIB). Atom trapping and fundamental symmetries. The goal of this theme is to explore and exploit the uses of advanced laser cooling and trapping techniques to manipulate atoms. There are three main areas of focus. First is in the application of the atom trap trace analysis (ATTA) technique for age determination of groundwater and ice by using radio-krypton dating. The next two trapping-based programs involve tests of fundamental symmetries in nature: the cooling and trapping of radium-225 with the aim of determining limits on an observation of its electric dipole moment and precision measurements of the beta decay properties of helium-6 to set limits on the tensor coupling constant. This is complemented by measurements of similar properties in lithium-8 and boron-8. Nuclear astrophysics. The goal of this theme is to enhance our understanding of how elements are created in the universe via explosive nucleosynthesis and how stars evolve. To meet the challenges of this theme, many of the capabilities of ATLAS are being enhanced, including the development of new beams through a new in-flight separator (RAISOR) and the anticipated neutron-generator upgrade of the Californium Rare Isotope Breeder Upgrade facility (nuCARIBU). These are coupled to state-of-the-art instruments such as the Canadian Penning Trap, Helical Orbit Spectrometer, Gammasphere, GRETINA, Multi-Sampling Ionization Chamber, the Fragment Mass Analyzer, and Argonne Gas-filled Fragment Analyzer, and a new low-background experimental area for decay studies. Nuclear structure. The goal of this theme is to understand the structure of nuclei, both stable and radioactive, in terms of single-particle properties, their shapes, and the dynamics governing reactions between them. These include questions such as what are the limits of nuclear stability and what are the properties of super heavy nuclei. As with the nuclear astrophysics theme, the capabilities of ATLAS, guided by the ATLAS user community, are continuously being enhanced to this end. The Division has strategic initiatives to play a leading role in the development of instrumentation and research programs at the FRIB. Quantum chromodynamics (QCD) and hadron physics. The goal of this theme is to lead major research programs focused on revealing the quark and gluon structure of protons, neutrons, nuclei, and short-lived mesons and baryons. These involve major programs at Jefferson Lab, Fermilab, and smaller facilities. They are complemented by theoretical endeavors centered on the question of how hadrons and their properties emerge from QCD. Out of these activities arise strategic initiatives to play a major role in the forthcoming Electron-Ion Collider (EIC).

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

Oak Ridge National Laboratory Technical Input for the Nuclear Regulatory Commission Review of the 2017 Edition of ASME Section III, Division 5, ‘High Temperature Reactors’

To assist the Nuclear Regulatory Commission in its decision making on endorsement of the American Society for Mechanical Engineers Boiler and Pressure Vessel Code Section III, Division 5 (2017 Edition) for development of advanced non-light water reactors, the following Division 5 portions were reviewed: Article HBB-2000 Material; Article HCB-2000 Material; Article HGB-2000 Material; Mandatory Appendix HBB-I-14 Tables and Figures; and, Nonmandatory Appendix HBB-U Guidelines for Restricted Material Specifications to Improve Performance in Certain Service Applications. In addition to the 2017 Edition, the same parts of the 2019 Edition have also been reviewed as indicated in various sections of the report. This review was conducted by a collaboration of national laboratory and private sector participants with significant industrial experience, including some heavy lifting and deep diving from Clarus Consulting, LLC., all intended to achieve an objective, independent, and practical perspective. The report provides recommendations, descriptions of the evaluation methods, and the source references for the data used. To build confidence required for endorsement of the Code, this review was conducted as a verification and validation of the above Code contents. The objective of verification is to ensure that the Code is free of error – direct or implied; contains the information needed for its use, including proper coverage of the Code-specified materials for the intended application, and completeness and adequacy of references to other portions of the Code. The objective of validation is to authenticate that the Code tabulations and graphs represent design inputs consistent with what are determined using rules and methods specified by the Code. The authentication process used data that were assembled and/or generated independent of Code development, while the methods of analysis followed Code-specified methods where appropriate. The designated portions for this review cover the five alloys codified for high temperature reactor applications in Division 5, i.e. 316 SS, 304 SS, 800H, 2¼Cr-1Mo, and 9Cr-1Mo-V, regarding their general requirements, permitted specifications and design stress intensity values for pressure-retaining applications, deterioration in service, fatigue acceptance test, permissible weld materials, tensile and yield strength, expected minimum stress-to-rupture values (including for Alloy 718), weld stress rupture factors, permissible materials for bolting use, and restricted specifications in certain service applications. Additionally, stress intensity values for bolting materials including 316 SS, 304 SS and alloy 718 were reviewed. Analysis and discussion are also provided on contents outside of these designated Code portions where it was deemed relevant and necessary to develop a technically sound understanding of issues relating to the designated portions. Due to unavailability of sufficient test data on welds during the review period, the weld stress rupture factors in Tables HBB-I-10.14A to E, which cover a total of ten tables for the five alloys welded with twenty-eight different weld metals (some with similar properties), have been deferred to a future review effort. The review identified mainly two types of issues. The first type includes instances where the Code is found factually incomplete or incorrect, such as obsolete materials specifications listings, missing tabulation of stresses for bolting. Changes to the Code are recommended in these cases. The second type of issue includes instances where the Code tabulations and graphs are found to be less conservative than the review analysis results. In these cases, recommendations are made for further review and consideration where the difference in conservatism exceeds 10%, which is our threshold for questioning technical adequacy, meriting a risk assessment by the Nuclear Regulatory Commission and/or reactor designers. It is noted that this effort has been executed using all available data and established methods of analysis, including methods and criteria specified and used by the Code. As such, the findings that are presented in quantitative detail, in a format for convenient comparison with the Code, and with identification of where further review is recommended, should provide a sound technical basis for decisions about quantifying the implications of the reduced design margins and technical adequacy/inadequacy to form a basis for conditioning specific Code tabulation values on endorsement. Recommendations for specific changes to the Code, however, entail design conservatism considerations beyond the scope of this review effort, and are not made in this report.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

Physics Division Strategic Plan: Science Drivers

The Physics Division Science Drivers articulate the overarching scientific objectives that we seek to address and that form the lifeblood of our Division. While many physics subfields are represented in the Physics Division’s scientific portfolio, we strive to maintain or achieve excellence and international leadership in only a few areas. While diversity of science and engineering efforts is strongly supported and provides the fertile soil for innovation, there are dominating areas in which we must excel to accomplish our mission that is stated as: “We design, execute and analyze experiments that challenge, improve and validate our understanding of fundamental physics underpinning LANL’s national security mission.”

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

Regulation of Chloroplast Division and Compartment Size (Final Technical Report)

During leaf growth and development, chloroplasts numbers increase as cells expand to maximize energy capture and photosynthetic capacity. Chloroplasts proliferate by dividing in the middle, producing a large population of small organelles of similar size and shape. This process is orchestrated by macromolecular complexes located both inside and outside the chloroplast whose assembly and contractile activity across the two envelope membranes must be coordinated and spatially regulated. Through research supported by our DOE funding, and by exploiting the powerful model system Arabidopsis thaliana, we have significantly advanced our knowledge of how coordination of the division complexes is achieved and how division-site placement is spatially restricted to the middle of the chloroplast. Using chloroplast division mutants, we gained new understanding of how chloroplast size and shape influence chloroplast movement and photosynthetic performance. We identified a gene contributing to natural variation in chloroplast size. Major findings are highlighted.

59 BASIC BIOLOGICAL SCIENCES↗

Nuclear and Chemical Sciences Division: Investment Strategy 2023

The mission of the Nuclear and Chemical Sciences (NACS) Division within the Physical and Life Sciences (PLS) Directorate is to advance scientific understanding, capabilities, and technologies in nuclear and particle physics, radiochemistry, forensic science, and isotope systems to support LLNL’s national security mission. NACS Division personnel conduct a diverse range of research activities in particle physics, nuclear physics, radiation detection, nuclear measurements, chemical and nuclear forensic science, nuclear and radiochemistry, isotope geochemistry, and environmental science. These areas are leveraged to address evolving national security challenges. Scientific research provides the foundation for addressing these challenges, and it is also the principal means of attracting, training, and retaining staff scientists who can deliver solutions across the Laboratory’s mission space. The overarching strategy is to position the NACS Division at the nexus between fundamental nuclear and chemical science research and nuclear security applications. This approach will support efforts to recruit, train, and retain top-flight scientists and engineers who will play a key role in executing the Laboratory’s core nuclear security missions, while also enhancing LLNL’s reputation as a center for innovative scientific research. This document describes the strategic vision that will be used to guide key investments aimed at enabling NACS scientists to lead new efforts and meet future challenges.

07 ISOTOPE AND RADIATION SOURCES↗

Saturn's rings. II - Condensations of light and optical thickness of Cassini's division

Condensations of light have been observed when Saturn's rings are seen almost edge on, and the sun and the earth are on opposite sides of the ring plane. These condensations are associated with ring C and Cassini's division. If the relative brightness between the two condensations and the optical thickness of ring C are known, we can calculate the optical thickness of Cassini's division. Using Barnard's and Sekiguchi's measurements, we have obtained a range from .01 to .05 for the optical thickness of Cassini's division. A brightness profile of the condensations which agrees well with visual observations is also presented.

Ferrin, I. R.↗

The formation of the Cassini division in Saturn's rings

An explanation for the size and location of the Cassini division in Saturn's rings is proposed. The explanation is based on the collective response of the particles in the ring to the resonant forcing by Mimas. An upper limit is calculated for the width of the gap that could be opened at a resonance. In addition, an estimate is obtained regarding the damping of the density waves by viscous and nonlinear effects. A picture is presented of the development of a gap. The results are compared with the observed properties of the divisions in Saturn's rings. The exact position of the inner edge of the Cassini division is difficult to predict, because the 2:1 resonance lies very near several weaker resonances (4:2 and 6:3 with Mimas, 4:1 with Tethys). However, the edge should lie near 17 seconds, and this is consistent with ground based observations.

Goldreich, P.↗

The Materials Division: A case study

The Materials Division at NASA's Lewis Research Center has been engaged in a program to improve the quality of its output. The division, its work, and its customers are described as well as the methodologies developed to assess and improve the quality of the Division's staff and output. Examples of these methodologies are presented and evaluated. An assessment of current progress is also presented along with a summary of future plans.

Grisaffe, Salvatore J.↗

Overview of the Applied Aerodynamics Division

A major reorganization of the Aeronautics Directorate of the Langley Research Center occurred in early 1989. As a result of this reorganization, the scope of research in the Applied Aeronautics Division is now quite different than that in the past. An overview of the current organization, mission, and facilities of this division is presented. A summary of current research programs and sample highlights of recent research are also presented. This is intended to provide a general view of the scope and capabilities of the division.

Source record↗

Space Science Division cumulative bibliography: 1989-1994

The Space Science Division at NASA's Ames Research Center is dedicated to research in astrophysics, exobiology, and planetary science. These research programs are structured around the study of origins and evolution of stars, planets, planetary atmospheres, and life, and address some of the most fundamental questions pursued by science; questions that examine the origin of life and of our place in the universe. This bibliography is the accumulation of peer-reviewed publications authored by Division scientists for the years 1989 through 1994. The list includes 777 papers published in over 5 dozen scientific journals representing the high productivity and interdisciplinary nature of the Space Science Division.

Morrison, D.↗

Microgravity effects during fertilization, cell division, development, and calcium metabolism in sea urchins

The overall objectives of this project are to explore the role of microgravity during fertilization, early development, cytoskeletal organization, and skeletal calcium deposition in a model development system: the sea urchin eggs and embryos. While pursuing these objectives, we have also helped to develop, test, and fly the Aquatic Research Facility (ARF) system. Cells were fixed at preselected time points to preserve the structures and organelles of interest with regards to cell biology events during development. The protocols used for the analysis of the results had been developed during the earlier part of this research and were applied for post-flight analysis using light and (immuno)fluorescence microscopy, scanning electron microscopy, and transmission electron microscopy. The structures of interest are: microtubules during fertilization, cell division, and cilia movement; microfilaments during cell surface restructuring and cell division; centrosomes and centrioles during cell division, cell differentiation, and cilia formation and movement; membranes, Golgi, endoplasmic reticulum, mitochondria, and chromosomes at all stages of development; and calcium deposits during spicule formation in late-stage embryos. In addition to further explore aspects important or living in space, several aspects of this research are also aimed at understanding diseases that affect humans on Earth which may be accelerated in space.

Schatten, Heide↗

Instrumentation and Controls Division Overview: Sensors Development for Harsh Environments at Glenn Research Center

The Instrumentation and Controls Division is responsible for planning, conducting and directing basic and applied research on advanced instrumentation and controls technologies for aerospace propulsion and power applications. The Division's advanced research in harsh environment sensors, high temperature high power electronics, MEMS (microelectromechanical systems), nanotechnology, high data rate optical instrumentation, active and intelligent controls, and health monitoring and management will enable self-feeling, self-thinking, self-reconfiguring and self-healing Aerospace Propulsion Systems. These research areas address Agency challenges to deliver aerospace systems with reduced size and weight, and increased functionality and intelligence for future NASA missions in advanced aeronautics, economical space transportation, and pioneering space exploration. The Division also actively supports educational and technology transfer activities aimed at benefiting all humankind.

Zeller, Mary V.↗

Infrared Avionics Signal Distribution using Wavelength Division Multiplexing

Pilots in the cockpits of aircrafts currently communicate with ground stations using Radio Frequency (RF) signals. Antennas mounted outside the aircraft receive and transmit RF signals from and to the ground stations. The RF signals received at the antennas are sent to the cockpit using coaxial cables. As the number of antennas needed to provide more than one frequency band in aircrafts increases, RF distribution media (such as coaxial cable) adds to the complexity and weight of the cockpit wiring. Concomitantly, the safety and signal to noise ratio also decreases due to the use of RF signals. The University of Oklahoma is collaborating with the National Aeronautics and Space Administration to develop optical fiber based schemes to replace the coaxial cable used for RF signal distribution within an aircraft. The project aims at exploiting emerging Wavelength Division Multiplexing (WDM) techniques to reduce the weight of cabling, and increase the signal to noise ratio and reliability. This will be achieved by wavelength division multiplexing the signals from the various antennas and then demultiplexing the signals to recover the original signals at the cockpit. This paper will show that (i) RF signals can not only be wavelength multiplexed at the end of a fiber, but additional signals can be inserted into the middle of the fiber using WDM technology, and (ii) the signals can also be successfully extracted by tapping into the middle of the fiber. We are currently extending our previous laboratory prototype (which could multiplex signals only at the end of the fiber) to include additional multiplexing and demultiplexing of RF signals from the middle of the optical backbone with a view to validating the proof of concept, and carrying out measurements to determine the effectiveness of Wavelength Division Multiplexing for avionics applications. A test bed to perform measurements of several relevant parameters for various modulation schemes and frequencies (such as VHF, UHF, and L-Band) has been implemented. In particular, results of transmitter and receiver noise, bit-error-rate (BER), effect of cross talk on the quality of the multiplexed signals, and Signal to Noise ratio and Carrier to Noise ratio, obtained using the aforementioned test bed, will be presented.

Atiquzzaman, Mohammed↗

Bayesian Research at the NASA Ames Research Center,Computational Sciences Division

NASA Ames Research Center is one of NASA s oldest centers, having started out as part of the National Advisory Committee on Aeronautics, (NACA). The site, about 40 miles south of San Francisco, still houses many wind tunnels and other aviation related departments. In recent years, with the growing realization that space exploration is heavily dependent on computing and data analysis, its focus has turned more towards Information Technology. The Computational Sciences Division has expanded rapidly as a result. In this article, I will give a brief overview of some of the past and present projects with a Bayesian content. Much more than is described here goes on with the Division. The web pages at http://ic.arc. nasa.gov give more information on these, and the other Division projects.

Morris, Robin D.↗

The Astrophysics Science Division Annual Report 2008

The Astrophysics Science Division (ASD) at Goddard Space Flight Center (GSFC) is one of the largest and most diverse astrophysical organizations in the world, with activities spanning a broad range of topics in theory, observation, and mission and technology development. Scientific research is carried out over the entire electromagnetic spectrum from gamma rays to radio wavelengths as well as particle physics and gravitational radiation. Members of ASD also provide the scientific operations for three orbiting astrophysics missions WMAP, RXTE, and Swift, as well as the Science Support Center for the Fermi Gamma-ray Space Telescope. A number of key technologies for future missions are also under development in the Division, including X-ray mirrors, and new detectors operating at gamma-ray, X-ray, ultraviolet, infrared, and radio wavelengths. This report includes the Division's activities during 2008.

Oegerle, William↗