The second Caltech-Jodrell Bank VLBI survey. 1: Observations of 91 of 193 sources

NASA Technical Reports Server (NTRS)

Taylor, G. B.; Vermeulen, R. C.; Pearson, T. J.; Readhead, A. C. S.; Henstock, D. R.; Browne, I. W. A.; Wilkinson, P. N.

1994-01-01

We define the sample for the second Caltech-Jodrell Bank very long base interferometry (VLBI) survey. This is a sample of 193 flat- or gigahertz-peaked-spectrum sources selected at 4850 MHz. This paper presents images of 91 sources with a resolution of approximately 1 mas, obtained using VLBI observations at 4992 MHz with a global array. The remaining images and the integrated radio spectra will be presented in a forthcoming paper by Henstock et al.

Planetary submillimeter spectroscopy

NASA Technical Reports Server (NTRS)

Klein, M. J.

1988-01-01

The aim is to develop a comprehensive observational and analytical program to study solar system physics and meterology by measuring molecular lines in the millimeter and submillimeter spectra of planets and comets. A primary objective is to conduct observations with new JPL and Caltech submillimeter receivers at the Caltech Submillimeter Observatory (CSO) on Mauna Kea, Hawaii. A secondary objective is to continue to monitor the time variable planetary phenomena (e.g., Jupiter and Uranus) at centimeter wavelength using the NASA antennas of the Deep Space Network (DSN).

A neural network-based approach to noise identification of interferometric GW antennas: the case of the 40 m Caltech laser interferometer

NASA Astrophysics Data System (ADS)

Acernese, F.; Barone, F.; de Rosa, M.; De Rosa, R.; Eleuteri, A.; Milano, L.; Tagliaferri, R.

2002-06-01

In this paper, a neural network-based approach is presented for the real time noise identification of a GW laser interferometric antenna. The 40 m Caltech laser interferometer output data provide a realistic test bed for noise identification algorithms because of the presence of many relevant effects: violin resonances in the suspensions, main power harmonics, ring-down noise from servo control systems, electronic noises, glitches and so on. These effects can be assumed to be present in all the first interferometric long baseline GW antennas such as VIRGO, LIGO, GEO and TAMA. For noise identification, we used the Caltech-40 m laser interferometer data. The results we obtained are pretty good notwithstanding the high initial computational cost. The algorithm we propose is general and robust, taking into account that it does not require a priori information on the data, nor a precise model, and it constitutes a powerful tool for time series data analysis.

ZTF Undergraduate Astronomy Institute at Caltech and Pomona College

NASA Astrophysics Data System (ADS)

Penprase, Bryan Edward; Bellm, Eric Christopher

2017-01-01

From the new Zwicky Transient Facility (ZTF), an NSF funded project based at Caltech, comes a new initiative for undergraduate research known as the Summer Undergraduate Astronomy Institute. The Institute brings together 15-20 students from across the world for an immersive experience in astronomy techniques before they begin their summer research projects. The students are primarly based at Caltech in their SURF program but also includes a large cohort of students enrolled in research internships at Pomona College in nearby Claremont CA. The program is intended to introduce students to research techniques in astronomy, laboratory and computational technologies, and to observational astronomy. Since many of the students are previously computer science or physics majors with little astronomy experience, this immersive experience has been extremely helpful for enabling students to learn about the terminologies, techniques and technologies of astronomy. The field trips to the Mount Wilson and Palomar telescopes deepen their knowledge and excitement about astronomy. Lectures about astronomical research from Caltech staff scientists and graduate students also provide context for the student research. Perhaps more importantly, the creation of a cohort of like-minded students, and the chance to reflect about careers in astronomy and research, give these students opportunities to consider themselves as future research scientists and help them immensely as they move forward in their careers. We discuss some of the social and intercultural aspects of the experience as well, as our cohorts typically include international students from many countries and several students from under-represented groups in science.

Inquiry-based Science Activities Using The Infrared Zoo and Infrared Yellowstone Resources at Cool Cosmos

NASA Astrophysics Data System (ADS)

Daou, D.; Gauthier, A.

2003-12-01

Inquiry-based activities that utilize the Cool Cosmos image galleries have been designed and developed by K12 teachers enrolled in The Invisible Universe Online for Teachers course. The exploration activities integrate the Our Infrared World Gallery (http://coolcosmos.ipac.caltech.edu/image_galleries/our_ir_world_gallery.html) with either the Infrared Zoo gallery (http://coolcosmos.ipac.caltech.edu/image_galleries/ir_zoo/index.html) or the Infrared Yellowstone image http://coolcosmos.ipac.caltech.edu/image_galleries/ir_yellowstone/index.html) and video (http://coolcosmos.ipac.caltech.edu/videos/ir_yellowstone/index.html) galleries. Complete instructor guides have been developed for the activities and will be presented by the authors in poster and CD form. Although the activities are written for middle and highschool learners, they can easily be adapted for college audiences. The Our Infrared World Gallery exploration helps learners think critically about visible light and infrared light as they compare sets of images (IR and visible light) of known objects. For example: by taking a regular photograph of a running faucet, can you tell if it is running hot or cold water? What new information does the IR image give you? The Infrared Zoo activities encourage learners to investigate the differences between warm and cold blooded animals by comparing sets of IR and visible images. In one activity, learners take on the role of a pit viper seeking prey in various desert and woodland settings. The main activities are extended into the real world by discussing and researching industrial, medical, and societal applications of infrared technologies. The Infrared Yellowstone lessons give learners a unique perspective on Yellowstone National Park and it's spectacular geologic and geothermal features. Infrared video technology is highlighted as learners make detailed observations about the visible and infrared views of the natural phenomena. The "Cool Cosmos" EPO activities are coordinated and managed by the SIRTF Science Center, based at the Infrared Processing and Analysis Center on the campus of the California Institute of Technology in Pasadena. You can find Cool Cosmos at http://coolcosmos.ipac.caltech.edu/

Transferring Technology to Industry

NASA Technical Reports Server (NTRS)

Wolfenbarger, J. Ken

2006-01-01

This slide presentation reviews the technology transfer processes in which JPL has been involved to assist in transferring the technology derived from aerospace research and development to industry. California Institute of Technology (CalTech), the organization that runs JPL, is the leading institute in patents for all U.S. universities. There are several mechanisms that are available to JPL to inform industry of these technological advances: (1) a dedicated organization at JPL, National Space Technology Applications (NSTA), (2) Tech Brief Magazine, (3) Spinoff magazine, and (4) JPL publications. There have also been many start-up organizations and businesses from CalTech.

Bioconversion study conducted by JPL

NASA Technical Reports Server (NTRS)

Kalvinskas, J.

1978-01-01

The Jet Propulsion Laboratory (JPL) of Caltech conducted a study of bioconversion as a means of identifying the role of biomass for meeting the national energy fuel and chemical requirements and the role and means for JPL-Caltech involvement in bioconversion. The bioconversion study included the following categories; biomass sources, chemicals from biomass, thermochemical conversion of biomass to fuels, biological conversion of biomass to fuels and chemicals, and basic bioconversion sciences. A detailed review is included of the bioconversion fields cited with specific conclusions and recommendations given for future research and development and overall biomass system engineering and economic studies.

Initial results from the Caltech/DRSI balloon-borne isotope experiment

NASA Technical Reports Server (NTRS)

Schindler, S. M.; Buffington, A.; Christian, E. C.; Grove, J. E.; Lau, K. H.; Stone, E. C.; Rasmussen, I. L.; Laursen, S.

1985-01-01

The Caltech/DSRI balloonborne High Energy Isotope Spectrometer Telescope (HEIST) was flown successfully from Palestine, Texas on 14 May, 1984. The experiment was designed to measure cosmic ray isotopic abundances from neon through iron, with incident particle energies from approx. 1.5 to 2.2 GeV/nucleon depending on the element. During approximately 38 hours at float altitude, 100,000 events were recorded with Z or = 6 and incident energies approx. 1.5 GeV/nucleon. We present results from the ongoing data analysis associated with both the preflight Bevalac calibration and the flight data.

Initial results from the Caltech/DSRI balloon-borne isotope experiment

NASA Technical Reports Server (NTRS)

Schindler, S. M.; Buffington, A.; Christian, E. C.; Grove, J. E.; Lau, K. H.; Stone, E. C.; Rasmussen, I. L.; Laursen, S.

1985-01-01

The Caltech/DSRI balloon-borne High Energy Isotope Spectrometer Telescope (HEIST) was flown successfully from Palestine, Texas on 14 May 1984. The experiment was designed to measure cosmic ray isotopic abundances from neon through iron, with incident particle energies from approximately 1.5 to 2.2 GeV/nucleon, depending on the element. During approximately 38 hours at float altitude, 10 to the 5th events were recorded with Z or = 6 and incident energies 1.5 GeV/nucleon. We present results from the ongoing data analysis associated with both the pre-flight Bevalac calibration and the flight data.

Obituary: James Adolph Westphal, 1930-2004

NASA Astrophysics Data System (ADS)

Danielson, G. Edward

2004-12-01

James A. Westphal died September 8, 2004. He had battled a neurological disease related to Alzheimer's for the past year. He was 74. James A. Westphal was born in Dubuque, Iowa, on June 13, 1930. He was raised in Tulsa, Oklahoma, and in Little Rock, Arkansas. Westphal earned his bachelor's degree in physics from the University of Tulsa in 1954, a year after he went to work as geophysical research group leader at Sinclair Research Lab in Tulsa. Westphal first got into the business of scientific instrumentation right after high school, when he did well-logging in Texas and Gulf Coast oil fields. In fact, his work at Sinclair Research Labs involved devising unorthodox methods for oil discovery; one of his discoveries of a new way of processing seismic data first brought him to the attention of Caltech professor Hewitt Dix, who is often considered the father of exploration geophysics. Westphal arrived at Caltech initially on a four-month leave of absence to devise a data processor for Dix, but never left. He discovered that the academic freedom individual professors enjoy was amenable to his own predilections, so he soon began branching out to other areas of scientific investigation at Caltech. Before long, he had teamed up with Bruce Murray to do thermal infrared scans of the moon in order to see if humans could even walk on the lunar surface without sinking into the dusty soil. Westphal and Murray's work showed that rocky areas could be identified with the thermal imaging, which in turn led to the inference that the Apollo astronauts could safely walk on the soil without sinking. Westphal and Murray also teamed up to do the first infrared imaging of Venus and Jupiter. Other projects at Caltech led to Westphal's being hired on permanently by Bob Sharp, who at the time was the geology division chairman. In the following years, Westphal involved himself in novel ways of studying volcanism in Hawaii and Mount St. Helens. He invented a simple and very sensitive tilt meter that allowed them to measure the volcano's expansion and help predict upcoming eruptions. Westphal also designed a way of creating a high-pressure aquarium for studies of deep-ocean animals as well as instruments for tracking glacial ice flows and capturing starlight. Caltech astronomers were pleased to discover that Westphal had an idea for an infrared camera for the historic 200-inch Hale Telescope--at the time the largest optical telescope in the world--that could measure the radiance of galaxies with greater precision and capture fainter galaxies than possible up to that time. He built various other instruments for the Hale Telescope, including a Silicon Intensified Target camera, which was a sort of transitional device between the photographic emulsion plates of the day and modern charged-coupled devices (CCDs) and which produced digital pictures with unparalleled clarity. The instrument is now in the Smithsonian's National Air and Space Museum's collection. Westphal and Jim Gunn (now at Princeton) recognized early that CCDs would revolutionize astronomy, and in the process of obtaining them for Palomar, Westphal and Gunn decided to put a team of astronomers together and design a CCD camera for use on the Hubble Space Telescope. Westphal was named principal investigator of the proposal and Jim Gunn was his deputy. They teamed with JPL to design the main camera for Hubble Space Telescope. (The Wide-Field / Planetary Camera), which proved to be an enormously successful part of the telescope's scientific mission. Westphal's research came up with a CCD coating that absorbed the UV photons and fluoresced back in the visible thus allowing the instrument to be used in the UV (The engineers dubbed the coating "mouse milk"). He didn't reveal the composition of the coating until NASA announced that the Caltech/JPL proposal was selected to provide the WF/PC Investigation. During the Hubble first light operations Jim had to diagnose the spherical aberration in the main 2.4 meter mirror, which caused the Hubble's initial focusing problems, while being photographed in real time by all the press cameras. A straight forward fix was devised for the WFPCII camera to bring the images into sharp focus. Once the repaired camera and the Hubble Space Telescope were safely in orbit, Westphal and his collaborators began receiving data on a regular basis. One of the early images of distant galaxies provided especially compelling evidence for the phenomenon known as gravitational lensing. "When this picture came in," Westphal said in a 1995 interview for Caltech's Engineering and Science magazine, "I put it under [Caltech physicist] Kip Thorne's door with a note saying, if you ever have any doubt about gravitational lenses, here's your proof." He was a member of the American Astronomical Society and served as the chairman of the Division for Planetary Sciences in 1979-1980. In 1991 Westphal received a MacArthur Fellowship. Already a tenured faculty member and the author of scores of refereed journal articles, and the creator of 15 patented inventions, Westphal was named director of Palomar Observatory in 1995 and served for three years. This assignment included being Caltech's representative to the Cara Board (which managed the KECK telescope). After lowering one of his custom-designed instruments into Old Faithful at Yellowstone National Park to study the geyser's cycling mechanism, he published a paper with Caltech graduate, Sue Kieffer, in 1997. The work, which received a good deal of media attention, confirmed previous assumptions about the geyser and also uncovered new details about the eruption cycle. Westphal took Caltech emeritus status in 1998, but remained active in research endeavors until his bout with this illness. Surviving Jim are his wife, Jean Westphal of Altadena; a son, Andrew Westphal, a daughter-in-law, Kim Taylor, and two granddaughters, Theresa and Laura Westphal, all of Richmond, California; two stepdaughters, Robin Stroll of Agoura Hills, California and Susan Stroll of Eagle Rock, California; and an uncle, Eddy Westphal of Indiana. A portion of this obituary was taken from a tribute by Robert Tindol published September 14, 2004 in an electronic Caltech Newsletter.

A cognitive operating system (COGNOSYS) for JPL's robot, phase 1 report

NASA Technical Reports Server (NTRS)

Mathur, F. P.

1972-01-01

The most important software requirement for any robot development is the COGNitive Operating SYStem (COGNOSYS). This report describes the Stanford University Artificial Intelligence Laboratory's hand eye software system from the point of view of developing a cognitive operating system for JPL's robot. In this, the Phase 1 of the JPL robot COGNOSYS task the installation of a SAIL compiler and a FAIL assembler on Caltech's PDP-10 have been accomplished and guidelines have been prepared for the implementation of a Stanford University type hand eye software system on JPL-Caltech's computing facility. The alternatives offered by using RAND-USC's PDP-10 Tenex operating sytem are also considered.

Data transfer nodes and demonstration of 100-400 Gbps wide area throughput using the Caltech SDN testbed

NASA Astrophysics Data System (ADS)

Mughal, A.; Newman, H.

2017-10-01

We review and demonstrate the design of efficient data transfer nodes (DTNs), from the perspective of the highest throughput over both local and wide area networks, as well as the highest performance per unit cost. A careful system-level design is required for the hardware, firmware, OS and software components. Furthermore, additional tuning of these components, and the identification and elimination of any remaining bottlenecks is needed once the system is assembled and commissioned, in order to obtain optimal performance. For high throughput data transfers, specialized software is used to overcome the traditional limits in performance caused by the OS, file system, file structures used, etc. Concretely, we will discuss and present the latest results using Fast Data Transfer (FDT), developed by Caltech. We present and discuss the design choices for three generations of Caltech DTNs. Their transfer capabilities range from 40 Gbps to 400 Gbps. Disk throughput is still the biggest challenge in the current generation of available hardware. However, new NVME drives combined with RDMA and a new NVME network fabric are expected to improve the overall data-transfer throughput and simultaneously reduce the CPU load on the end nodes.

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Development of Scanning Ultrafast Electron Microscope Capability.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Collins, Kimberlee Chiyoko; Talin, Albert Alec; Chandler, David W.

Modern semiconductor devices rely on the transport of minority charge carriers. Direct examination of minority carrier lifetimes in real devices with nanometer-scale features requires a measurement method with simultaneously high spatial and temporal resolutions. Achieving nanometer spatial resolutions at sub-nanosecond temporal resolution is possible with pump-probe methods that utilize electrons as probes. Recently, a stroboscopic scanning electron microscope was developed at Caltech, and used to study carrier transport across a Si p-n junction [ 1 , 2 , 3 ] . In this report, we detail our development of a prototype scanning ultrafast electron microscope system at Sandia National Laboratoriesmore » based on the original Caltech design. This effort represents Sandia's first exploration into ultrafast electron microscopy.« less

Development And Application Of The Ion Microprobe For Analysis Of Extraterrestrial Materials

NASA Technical Reports Server (NTRS)

Wasserburg, G. J.

2001-01-01

This report covers the work carried out under NASA Grant NAG5-4083. The research was directed toward analyses of early solar system material, of presolar grains preserved in meteorites, and toward theoretical studies of nucleosynthesis in stars related to the chemical evolution of the galaxy and the formation of the solar system. The work was carried out over the time period 15 February 1998 - 31 May 2001 and involved the participation of the following individuals: M. Busso, Visiting Associate, Professor of Astrophysics, Perugia University, Italy; B.-G. Choi, research fellow, now Associate Professor at Seoul National University, Korea; H. C. Connolly, research fellow, now at Kingsborough Community College, CUNY; R. Gallino, Visiting Associate, Professor of Astrophysics, University of Torino; Y. Guan, Smithsonian Institution; C. Hohenberg, Professor of Physics, Washington University, St. Louis; M. Heinrich, electronics and systems engineer, Caltech; W. Hsu, research fellow, Caltech; T. LaTourrette, research fellow, now at Rand Corporation; G. R. Huss, Senior Research Scientist, now at Arizona State University; N. Krestina, research fellow in geochemistry, Caltech; G. J. MacPherson, Smithsonian Institution; K. Nollett, research fellow in astrophysics; Y.-Z. Qian, Professor of Physics, University of Minnesota; G. Srinivasan, research fellow, now Research Scientist, Physical Research Laboratory, Ahmedabad, India.

HTTP as a Data Access Protocol: Trials with XrootD in CMS’s AAA Project

NASA Astrophysics Data System (ADS)

Balcas, J.; Bockelman, B. P.; Kcira, D.; Newman, H.; Vlimant, J.; Hendricks, T. W.; CMS Collaboration

2017-10-01

The main goal of the project to demonstrate the ability of using HTTP data federations in a manner analogous to the existing AAA infrastructure of the CMS experiment. An initial testbed at Caltech has been built and changes in the CMS software (CMSSW) are being implemented in order to improve HTTP support. The testbed consists of a set of machines at the Caltech Tier2 that improve the support infrastructure for data federations at CMS. As a first step, we are building systems that produce and ingest network data transfers up to 80 Gbps. In collaboration with AAA, HTTP support is enabled at the US redirector and the Caltech testbed. A plugin for CMSSW is being developed for HTTP access based on the DaviX software. It will replace the present fork/exec or curl for HTTP access. In addition, extensions to the XRootD HTTP implementation are being developed to add functionality to it, such as client-based monitoring identifiers. In the future, patches will be developed to better integrate HTTP-over-XRootD with the Open Science Grid (OSG) distribution. First results of the transfer tests using HTTP are presented in this paper together with details about the initial setup.

Early Days of SIS Receivers

NASA Astrophysics Data System (ADS)

Woody, D. P.

2009-12-01

The modern era of millimeter and submillimeter spectral line observations and interferometry started at end of the 1979 with the invention of the Superconductor-Insulator-Superconductor (SIS) mixer. Tom Phillips co-invented this device while working at Bell Telephone Labs (BTL) in Murray Hill, NJ. His group built the first astronomically useful SIS heterodyne receiver which was deployed on the Leighton 10.4 m telescope at the Caltech Owens Valley Radio Observatory (OVRO) in the same year. Tom Phillips joined the Caltech faculty in the early 1980s where his group continues to lead the way in developing state-of-the-art SIS receivers throughout the millimeter and submillimeter wavelength bands. The rapid progress in millimeter and submillimeter astronomy during 1980s required developments on many fronts including the theoretical understanding of the device physics, advances in device fabrication, microwave and radio frequency (RF) circuit design, mixer block construction, development of wideband low-noise intermediate frequency (IF) amplifiers and the telescopes used for making the observations. Many groups around the world made important contributions to this field but the groups at Caltech and the Jet Propulsion Laboratory (JPL) under the leadership of Tom Phillips made major contributions in all of these areas. The end-to-end understanding and developments from the theoretical device physics to the astronomical observations and interpretation has made this group uniquely productive.

"The awe in which biologists hold physicists": Frits Went's first phytotron at Caltech, and an experimental definition of the biological environment.

PubMed

Munns, David P D

2014-01-01

After Darwin, experimental biology sought to unravel organisms. By the early twentieth century, organisms were broadly conceived as the product of their heredity and their environment. Much historical work has explored the scientific attack on the genotype, particularly through the new science of genetics. This article explores the tandem efforts to assert experimental control over the environment in which plants grew and developed. The case described here concerns the creation of the first phytotron at Caltech by botanist and plant physiologist Frits Went. Opening in 1949, the phytotron was a plant laboratory that, across a series of rooms and chambers, kept genes constant while regulating and maintaining defined ranges of known environments. This article details the context in which the phytotron emerged, how the phytotron gained its sobriquet, and how it served to cement the "environment" as a category of biological knowledge. Describing the institutional context of Caltech, its interdisciplinary culture, and its encouragement of adopting technology into biological science, I argue that the phytotron and the commensurate category of the "environment", were the product of the familiar movement to integrate the physical and biological sciences. In addition, however, the creation of the phytotron was also a broader story of plant physiologists establishing a definition of the "environment" in both physical and technological terms.

Exoplanet Orbit Database | Exoplanet Data Explorer

Science.gov Websites

, Strasbourg, France, NASA's Astrophysics Data System, the NASA Exoplanet Archive (and, formerly, the NASA/IPAC /Caltech. This research received generous funding from NASA and the NSF.

Internet-Based Solutions for a Secure and Efficient Seismic Network

NASA Astrophysics Data System (ADS)

Bhadha, R.; Black, M.; Bruton, C.; Hauksson, E.; Stubailo, I.; Watkins, M.; Alvarez, M.; Thomas, V.

2017-12-01

The Southern California Seismic Network (SCSN), operated by Caltech and USGS, leverages modern Internet-based computing technologies to provide timely earthquake early warning for damage reduction, event notification, ShakeMap, and other data products. Here we present recent and ongoing innovations in telemetry, security, cloud computing, virtualization, and data analysis that have allowed us to develop a network that runs securely and efficiently.Earthquake early warning systems must process seismic data within seconds of being recorded, and SCSN maintains a robust and resilient network of more than 350 digital strong motion and broadband seismic stations to achieve this goal. We have continued to improve the path diversity and fault tolerance within our network, and have also developed new tools for latency monitoring and archiving.Cyberattacks are in the news almost daily, and with most of our seismic data streams running over the Internet, it is only a matter of time before SCSN is targeted. To ensure system integrity and availability across our network, we have implemented strong security, including encryption and Virtual Private Networks (VPNs).SCSN operates its own data center at Caltech, but we have also installed real-time servers on Amazon Web Services (AWS), to provide an additional level of redundancy, and eventually to allow full off-site operations continuity for our network. Our AWS systems receive data from Caltech-based import servers and directly from field locations, and are able to process the seismic data, calculate earthquake locations and magnitudes, and distribute earthquake alerts, directly from the cloud.We have also begun a virtualization project at our Caltech data center, allowing us to serve data from Virtual Machines (VMs), making efficient use of high-performance hardware and increasing flexibility and scalability of our data processing systems.Finally, we have developed new monitoring of station average noise levels at most stations. Noise monitoring is effective at identifying anthropogenic noise sources and malfunctioning acquisition equipment. We have built a dynamic display of results with sorting and mapping capabilities that allow us to quickly identify problematic sites and areas with elevated noise.

Monitor and Control of the Deep-Space network via Secure Web

NASA Technical Reports Server (NTRS)

Lamarra, N.

1997-01-01

(view graph) NASA lead center for robotic space exploration. Operating division of Caltech/Jet Propulsion Laboratory. Current missions, Voyagers, Galileo, Pathfinder, Global Surveyor. Upcoming missions, Cassini, Mars and New Millennium.

Glass Stronger than Steel

DOE R&D Accomplishments Database

Yarris, Lynn

2011-03-28

A new type of damage-tolerant metallic glass, demonstrating a strength and toughness beyond that of steel or any other known material, has been developed and tested by a collaboration of researchers from Berkeley Lab and Caltech.

VizieR Online Data Catalog: NIR albedos of main-belt asteroids (Masiero+, 2014)

NASA Astrophysics Data System (ADS)

Masiero, J. R.; Grav, T.; Mainzer, A. K.; Nugent, C. R.; Bauer, J. M.; Stevenson, R.; Sonnett, S.

2017-04-01

To fit for NIR albedos of main-belt asteroids, we use data from the WISE/NEOWISE all-sky single exposure source table, which are available for download from the Infrared Science Archive (IRSA, http://irsa.ipac.caltech.edu ; Cutri et al. 2012, xplanatory Supplement to the WISE All-Sky Data Release Products, http://wise2.ipac.caltech.edu/docs/release/allsky/expsup/index.html). We extract photometric measurements of all asteroids observed by WISE following the technique described in Masiero et al. (2011, J/ApJ/741/68) and Mainzer et al. (2011ApJ...731...53M). In particular, we use the NEOWISE observations reported to the MPC and included in the MPC's minor planet observation database as the final validated list of reliable NEOWISE detections of solar system objects. (1 data file).

JPL-20170926-TECHf-0001-Robot Descends into Alaska Moulin

NASA Image and Video Library

2017-09-26

JPL engineer Andy Klesh lowers a robotic submersible into a moulin. Klesh and JPL's John Leichty used robots and probes to explore the Matanuska Glacier in Alaska this past July. Image Credit: NASA/JPL-Caltech

The Caltech Concurrent Computation Program - Project description

NASA Technical Reports Server (NTRS)

Fox, G.; Otto, S.; Lyzenga, G.; Rogstad, D.

1985-01-01

The Caltech Concurrent Computation Program wwhich studies basic issues in computational science is described. The research builds on initial work where novel concurrent hardware, the necessary systems software to use it and twenty significant scientific implementations running on the initial 32, 64, and 128 node hypercube machines have been constructed. A major goal of the program will be to extend this work into new disciplines and more complex algorithms including general packages that decompose arbitrary problems in major application areas. New high-performance concurrent processors with up to 1024-nodes, over a gigabyte of memory and multigigaflop performance are being constructed. The implementations cover a wide range of problems in areas such as high energy and astrophysics, condensed matter, chemical reactions, plasma physics, applied mathematics, geophysics, simulation, CAD for VLSI, graphics and image processing. The products of the research program include the concurrent algorithms, hardware, systems software, and complete program implementations.

Leon Knopoff (1926-2011)

NASA Astrophysics Data System (ADS)

Davis, Paul; Jackson, David; Gilbert, Freeman

2011-06-01

Leon Knopoff died at his home in Sherman Oaks, Calif., on 20 January 2011 at the age of 85. A man of wide-ranging talents, he had the rare distinction of being simultaneously a professor of physics, a professor of geophysics, and a research musicologist at the University of California, Los Angeles (UCLA). As an undergraduate he studied electrical engineering and obtained his Ph.D. in physics and mathematics at the California Institute of Technology (Caltech) in 1949. He was recruited to the Institute of Geophysics (now the Institute of Geophysics and Planetary Physics) at UCLA in 1950 by Louis Slichter, where he became a professor of geophysics in 1957 and of geophysics and physics in 1961. He became a research musicologist in the UCLA Institute of Ethnomusicology soon after it was formed in 1960. Other appointments included faculty positions at Miami University in Ohio (1948-1950) and Caltech (1962-1963) and visiting appointments at Cambridge, Karlsruhe, Harvard, Santiago, Trieste, and Venice.

Making the Case: Workforce, Education, Public Outreach and Communications as Mission-Critical Activities

NASA Astrophysics Data System (ADS)

Squires, Gordon K.; Brewer, Janesse; Dawson, Sandra; Program Organizing Committee "Making the Case" workshop 2017

2018-01-01

Increasingly, next-generation science projects will never see first light, or will lose their “right to operate” if they are unable to be responsive to emerging societal values and interests. Science projects with a robust and professional Workforce, Education, Public Outreach and Communications (WEPOC) architecture are able to engage and welcome public discourse about science, trade-offs, and what it means to be a good neighbor in a community. In this talk I will update the latest WEPOC efforts for TMT & NASA projects at Caltech/IPAC, and highlight how WEPOC has entered the critical path for many large, international science projects. I will also present a draft working document being developed by many of the world's largest astronomy and high-energy physics WEPOC leaders as an outcome from a "Making the Case" conference held at Caltech in spring 2017.

An observation of the Galactic center hard X-ray source, 1E 1740.7-2942, with the Caltech coded-aperture telescope

NASA Technical Reports Server (NTRS)

Heindl, William A.; Cook, Walter R.; Grunsfeld, John M.; Palmer, David M.; Prince, Thomas A.; Schindler, Stephen M.; Stone, Edward C.

1993-01-01

The Galactic center region hard X-ray source IE 1740.7-2942 has been observed with the Caltech Gamma-Ray Imaging Payload (GRIP) from Alice Springs, Australia, on 1988 April 12 and on 1989 April 3 and 4. We report here results from the 1989 measurements based on 14 hr of observation of the Galactic center region. The observations showed IE 1740.7-2942 to be in its normal state, having a spectrum between 35 and 200 keV characterized by a power law with an exponent of -2.2 +/- 0.3 and flux at 100 keV of (7.0 +/- 0.7) x 10 exp -5 sq cm s keV. No flux was detected above 200 keV. A search for time variability in the spectrum of IE 1740.7-2942 on one hour time scales showed no evidence for variability.

The MKID Camera

NASA Astrophysics Data System (ADS)

Maloney, P. R.; Czakon, N. G.; Day, P. K.; Duan, R.; Gao, J.; Glenn, J.; Golwala, S.; Hollister, M.; LeDuc, H. G.; Mazin, B.; Noroozian, O.; Nguyen, H. T.; Sayers, J.; Schlaerth, J.; Vaillancourt, J. E.; Vayonakis, A.; Wilson, P.; Zmuidzinas, J.

2009-12-01

The MKID Camera project is a collaborative effort of Caltech, JPL, the University of Colorado, and UC Santa Barbara to develop a large-format, multi-color millimeter and submillimeter-wavelength camera for astronomy using microwave kinetic inductance detectors (MKIDs). These are superconducting, micro-resonators fabricated from thin aluminum and niobium films. We couple the MKIDs to multi-slot antennas and measure the change in surface impedance produced by photon-induced breaking of Cooper pairs. The readout is almost entirely at room temperature and can be highly multiplexed; in principle hundreds or even thousands of resonators could be read out on a single feedline. The camera will have 576 spatial pixels that image simultaneously in four bands at 750, 850, 1100 and 1300 microns. It is scheduled for deployment at the Caltech Submillimeter Observatory in the summer of 2010. We present an overview of the camera design and readout and describe the current status of testing and fabrication.

NASA/IPAC Infrared Archive's General Image Cutouts Service

NASA Astrophysics Data System (ADS)

Alexov, A.; Good, J. C.

2006-07-01

The NASA/IPAC Infrared Archive (IRSA) ``Cutouts" Service (http://irsa.ipac.caltech.edu/applications/Cutouts) is a general tool for creating small ``cutout" FITS images and JPEGs from collections of data archived at IRSA. This service is a companion to IRSA's Atlas tool (http://irsa.ipac.caltech.edu/applications/Atlas/), which currently serves over 25 different data collections of various sizes and complexity and returns entire images for a user-defined region of the sky. The Cutouts Services sits on top of Atlas and extends the Atlas functionality by generating subimages at locations and sizes requested by the user from images already identified by Atlas. These results can be downloaded individually, in batch mode (using the program wget), or as a tar file. Cutouts re-uses IRSA's software architecture along with the publicly available Montage mosaicking tools. The advantages and disadvantages of this approach to generic cutout serving will be discussed.

Robust nonlinear control of vectored thrust aircraft

NASA Technical Reports Server (NTRS)

Doyle, John C.; Murray, Richard; Morris, John

1993-01-01

An interdisciplinary program in robust control for nonlinear systems with applications to a variety of engineering problems is outlined. Major emphasis will be placed on flight control, with both experimental and analytical studies. This program builds on recent new results in control theory for stability, stabilization, robust stability, robust performance, synthesis, and model reduction in a unified framework using Linear Fractional Transformations (LFT's), Linear Matrix Inequalities (LMI's), and the structured singular value micron. Most of these new advances have been accomplished by the Caltech controls group independently or in collaboration with researchers in other institutions. These recent results offer a new and remarkably unified framework for all aspects of robust control, but what is particularly important for this program is that they also have important implications for system identification and control of nonlinear systems. This combines well with Caltech's expertise in nonlinear control theory, both in geometric methods and methods for systems with constraints and saturations.

Supreme Court Hears Privacy Case Between NASA and Jet Propulsion Laboratory Scientists

NASA Astrophysics Data System (ADS)

Showstack, Randy

2010-10-01

After NASA put into practice the 2004 Homeland Security Presidential Directive-12, known as HSPD-12, Dennis Byrnes talked to then-NASA administrator Michael Griffin. Byrnes recalls that Griffin told him in 2007 that if he didn’t like the agency's implementation of HSPD-12, he should go to court. That's exactly what Byrnes, an employee of the California Institute of Technology (Caltech) working as a senior engineer at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif., did. Concerned about prying and open-ended background investigations of federal contractors through NASA's implementation of HSPD-12, he, along with lead plaintiff Robert Nelson and 26 other Caltech employees working at JPL, sued NASA. Following several lower court decisions, including an injunction issued by a U.S. federal appeals court in response to a plaintiff motion, the case made it all the way to the U.S. Supreme Court, which heard oral arguments on 5 October.

Investigations into the metabolic diversity of microorganisms as part of microbial diversity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leadbetter, Jared

DOE funds supported a key portion of the MBL Microbial Diversity (Woods Hole) program across 6 complete summers. The initial 4 years of the funded period were overseen by two co-Directors, Daniel Buckley (Cornell) and Steve Zinder (Cornell), who then completed their term. The final 2 summers were overseen by 2 new co-Directors, Jared R. Leadbetter (Caltech) and Dianne Newman (Caltech). The 6 funded summer iterations of the course included the incorporation of new themes such as single cell approaches applied to natural microbial communities (cell separation and sorting, genome amplification from single cells, and the use of Nano-SIMS tomore » examine assimilation of carbon and nitrogen from isotopically labeled substrates into single cells), genetics and genomics on bacteria freshly isolated during the course of the programs, quantitative systems biology, and modern quantitative light microscopy.« less

The cryomechanical design of MUSIC: a novel imaging instrument for millimeter-wave astrophysics at the Caltech Submillimeter Observatory

NASA Astrophysics Data System (ADS)

Hollister, Matthew I.; Czakon, Nicole G.; Day, Peter K.; Downes, Thomas P.; Duan, Ran; Gao, Jiansong; Glenn, Jason; Golwala, Sunil R.; LeDuc, Henry G.; Maloney, Philip R.; Mazin, Benjamin A.; Nguyen, Hien Trong; Noroozian, Omid; Sayers, Jack; Schlaerth, James; Siegel, Seth; Vaillancourt, John E.; Vayonakis, Anastasios; Wilson, Philip; Zmuidzinas, Jonas

2010-07-01

MUSIC (Multicolor Submillimeter kinetic Inductance Camera) is a new facility instrument for the Caltech Submillimeter Observatory (Mauna Kea, Hawaii) developed as a collaborative effect of Caltech, JPL, the University of Colorado at Boulder and UC Santa Barbara, and is due for initial commissioning in early 2011. MUSIC utilizes a new class of superconducting photon detectors known as microwave kinetic inductance detectors (MKIDs), an emergent technology that offers considerable advantages over current types of detectors for submillimeter and millimeter direct detection. MUSIC will operate a focal plane of 576 spatial pixels, where each pixel is a slot line antenna coupled to multiple detectors through on-chip, lumped-element filters, allowing simultaneously imaging in four bands at 0.86, 1.02, 1.33 and 2.00 mm. The MUSIC instrument is designed for closed-cycle operation, combining a pulse tube cooler with a two-stage Helium-3 adsorption refrigerator, providing a focal plane temperature of 0.25 K with intermediate temperature stages at approximately 50, 4 and 0.4 K for buffering heat loads and heat sinking of optical filters. Detector readout is achieved using semi-rigid coaxial cables from room temperature to the focal plane, with cryogenic HEMT amplifiers operating at 4 K. Several hundred detectors may be multiplexed in frequency space through one signal line and amplifier. This paper discusses the design of the instrument cryogenic hardware, including a number of features unique to the implementation of superconducting detectors. Predicted performance data for the instrument system will also be presented and discussed.

IP Network Design and Implementation for the Caltech-USGS Element of TriNet

NASA Astrophysics Data System (ADS)

Johnson, M. L.; Busby, R.; Watkins, M.; Schwarz, S.; Hauksson, E.

2001-12-01

The new seismic network IP numbering scheme for the Caltech-USGS element of TriNet is designed to provide emergency response plans for computer outages and/or telemetry circuit failures so that data acquisition may continue with minimal interruption. IP numbers from the seismic stations through the Caltech acquisition machines are numbered using private, non-routable IP addresses, which allows the network administrator to create redundancy in the network design, more freedom in choosing IP numbers, and uniformity in the LAN and WAN network addressing. The network scheme used by the Caltech-USGS element of TriNet is designed to create redundancy and load sharing over three or more T1 circuits. A T1 circuit can support 80 dataloggers sending data at a design rate of 19.2 kbps or 120 dataloggers transmitting at a nominal rate of 12.8 kbps. During a circuit detour, the 80 dataloggers on the failed T1 are equally divided between the remaining two circuits. This increases the loads on the remaining two circuits to 120 dataloggers, which is the maximum load each T1 can handle at the nominal rate. Each T1 circuit has a router interface onto a LAN at Caltech with an independent subnet address. Some devices, such as Solaris computers, allow a single interface to be numbered with several IP addresses, a so called "multinetted" interface. This allows the central acquisition computers to appear with distinct addresses that are routable via different T1 circuits, but simplifies the physical cables between devices. We identify these T1 circuits as T1-1, T1-2, and T1-3. At the remote end, each Frame Relay Access Device (FRAD) and connected datalogger(s) is a subnetted LAN. The numbering is arranged so the second octet in the LAN IP address of the FRAD and datalogger identify the datalogger's primary and alternate T1 circuits. For example; a LAN with an IP address of 10.12.0.0/24 has T1-1 as its primary T1, and T1-2 as its alternate circuit. Stations with this number scheme are sometimes referred to as group "12". LANs with IP addresses of 10.23.0.0/24 have T1-2 as the primary circuit, and T1-3 as the alternate circuit. Static routes on the acquisition system are used to direct traffic through the primary T1. The network can operate in one of three modes. The most common and desirable mode is "normal", where all three T1's are operational and Caltech has both a primary and secondary central acquisition system running. The second mode is a "failover", where the primary acquisition system is down (due to maintenance or failure) and the secondary acquisition system assumes the primary role. This includes sending acknowledgments to dataloggers and multicasts to the rest of the network. The third mode is a circuit detour. The port numbers on the central acquisition system for the dataloggers on the failed T1 are changed to match the auxiliary ports on the dataloggers. This allows for the auxiliary ports on the dataloggers to receive acknowledgements from the acquiring system through the detoured circuit. The static routes on the system are changed to go through the detoured circuit as specified by the group's IP numbers. At this point the two working T1's will be running at full capacity but the data acquisition will continue with minimal interruption while the third T1 is being restored. The primary acquisition computer continues to listen for data on the failed T1 should things improve spontaneously.

Synchrotron Radiation Research--An Overview.

ERIC Educational Resources Information Center

Bienenstock, Arthur; Winick, Herman

1983-01-01

Discusses expanding user community seeking access to synchrotron radiation sources, properties/sources of synchrotron radiation, permanent-magnet technology and its impact on synchrotron radiation research, factors limiting power, the density of synchrotron radiation, and research results illustrating benefit of higher flux and brightness. Also…

Einstein and Millikan

NASA Astrophysics Data System (ADS)

Erwin, Charlotte

2005-03-01

Albert Einstein traveled to America by boat during the great depression to consult with scientists at the California Institute of Technology. He was a theoretical physicist, a Nobel Prize winner, and a 20th century folk hero. Few members of the general public understood his theories, but they idolized him all the same. The invitation came from physicist Robert Millikan, who had initiated a visiting-scholars program at Caltech shortly after he became head of the school in 1921. Einstein's visits to the campus in 1931, 1932, and 1933 capped Millikan's campaign to make Caltech one of the physics capitals of the world. Mount Wilson astronomer Edwin Hubble's discovery that redshifts are proportional to their distances from the observer challenged Einstein's cosmological picture of a static universe. The big question at Caltech in 1931 was whether Einstein would give up his cosmological constant and accept the idea of an expanding universe. By day, Einstein discussed his theory and its interpretation at length with Richard Tolman, Hubble, and the other scientists on the campus. By night, Einstein filled his travel diary with his personal impressions. During his third visit, Einstein sidestepped as long as possible the question of whether conditions in Germany might prevent his return there. After the January 30 announcement that Hitler had become chancellor of Germany, the question could no longer be evaded. He postponed his return trip for a few weeks and then went to Belgium for several months instead of to Berlin. In the fall of 1933, Albert Einstein returned to the United States as an emigre and became a charter member of Abraham Flexner's new Institute for Advanced Study in Princeton, New Jersey. Why did Einstein go to Princeton and not Pasadena?

Recent optical activity of the blazar OT 355

NASA Astrophysics Data System (ADS)

Bachev, R.; Kurtenkov, A.; Nikolov, Y.; Spassov, B.; Boeva, S.; Latev, G.; Dimitrova, R. V. Munoz

2017-06-01

The Flat Spectrum Radio Quasar OT 355 (also known as 7C 173240.70+385949.00, z=0.975) was typically observed to be in the optical between 16th and 21th magnitude (CRTS, http://nesssi.cacr.caltech.edu/catalina/20011332/113321380764100137p.html).

Dynamic Resource Allocation in Conservation Planning

DTIC Science & Technology

2011-08-01

0932392 and IIS-0953413, the Caltech Center for the Mathematics of Information, and by the US Fish and Wildlife Service. We thank J. Bakker, J. Bush ...Moilanen, A.; Pakkala, T.; and Kuussaari, M. 1996. The quantitative incidence function model and persistence of an endangered butterfly metapopulation

Lunar and planetary studies

NASA Technical Reports Server (NTRS)

Muhleman, Duane O.; Goldreich, P.; Ingersoll, A. P.; Westphal, J. A.

1988-01-01

This grant supports the core program in planetary astronomy at Caltech. The research includes observations in the IR, sub-mm, mm and cm wavelengths at national and Caltech observatories with a strong emphasis on integrating the observations with spacecraft data and with models of atmospheric structure, dynamics and chemistry. Muhleman's group made extensive observations of Saturn, Uranus and Neptune which are being interpreted in terms of deep atmospheric structures which are obvious in the 2 and 6 cm maps of Saturn and Uranus. The microwave measurements are one of the few sources of information below the 2 bar level. Goldreich is investigating the dynamics of narrow rings with postdoctoral fellow, Pierre-Yves Longaretti. Their work has focused on the role of collisional stresses on the precession of the rings, since the Voyager radio science results imply that the previous model based on the ring's self-gravity is not the entire story. In addition Borderies, Goldreich and Tremaine have completed an investigation of the dynamics of the Encke division in Saturn's A ring.

SOFT: a synthetic synchrotron diagnostic for runaway electrons

NASA Astrophysics Data System (ADS)

Hoppe, M.; Embréus, O.; Tinguely, R. A.; Granetz, R. S.; Stahl, A.; Fülöp, T.

2018-02-01

Improved understanding of the dynamics of runaway electrons can be obtained by measurement and interpretation of their synchrotron radiation emission. Models for synchrotron radiation emitted by relativistic electrons are well established, but the question of how various geometric effects—such as magnetic field inhomogeneity and camera placement—influence the synchrotron measurements and their interpretation remains open. In this paper we address this issue by simulating synchrotron images and spectra using the new synthetic synchrotron diagnostic tool SOFT (Synchrotron-detecting Orbit Following Toolkit). We identify the key parameters influencing the synchrotron radiation spot and present scans in those parameters. Using a runaway electron distribution function obtained by Fokker-Planck simulations for parameters from an Alcator C-Mod discharge, we demonstrate that the corresponding synchrotron image is well-reproduced by SOFT simulations, and we explain how it can be understood in terms of the parameter scans. Geometric effects are shown to significantly influence the synchrotron spectrum, and we show that inherent inconsistencies in a simple emission model (i.e. not modeling detection) can lead to incorrect interpretation of the images.

Real time observation of mouse fetal skeleton using a high resolution X-ray synchrotron

PubMed Central

Chang, Dong Woo; Kim, Bora; Shin, Jae Hoon; Yun, Young Min; Je, Jung Ho; Hwu, Yeu kuang; Yoon, Jung Hee

2011-01-01

The X-ray synchrotron is quite different from conventional radiation sources. This technique may expand the capabilities of conventional radiology and be applied in novel manners for special cases. To evaluate the usefulness of X-ray synchrotron radiation systems for real time observations, mouse fetal skeleton development was monitored with a high resolution X-ray synchrotron. A non-monochromatized X-ray synchrotron (white beam, 5C1 beamline) was employed to observe the skeleton of mice under anesthesia at embryonic day (E)12, E14, E15, and E18. At the same time, conventional radiography and mammography were used to compare with X-ray synchrotron. After synchrotron radiation, each mouse was sacrificed and stained with Alizarin red S and Alcian blue to observe bony structures. Synchrotron radiation enabled us to view the mouse fetal skeleton beginning at gestation. Synchrotron radiation systems facilitate real time observations of the fetal skeleton with greater accuracy and magnification compared to mammography and conventional radiography. Our results show that X-ray synchrotron systems can be used to observe the fine structures of internal organs at high magnification. PMID:21586868

SYNCHROTRON HEATING BY A FAST RADIO BURST IN A SELF-ABSORBED SYNCHROTRON NEBULA AND ITS OBSERVATIONAL SIGNATURE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Yuan-Pei; Dai, Zi-Gao; Zhang, Bing, E-mail: zhang@physics.unlv.edu

Fast radio bursts (FRBs) are mysterious transient sources. If extragalactic, as suggested by their relative large dispersion measures, their brightness temperatures must be extremely high. Some FRB models (e.g., young pulsar model, magnetar giant flare model, or supra-massive neutron star collapse model) suggest that they may be associated with a synchrotron nebula. Here we study a synchrotron-heating process by an FRB in a self-absorbed synchrotron nebula. If the FRB frequency is below the synchrotron self-absorption frequency of the nebula, electrons in the nebula would absorb FRB photons, leading to a harder electron spectrum and enhanced self-absorbed synchrotron emission. In themore » meantime, the FRB flux is absorbed by the nebula electrons. We calculate the spectra of FRB-heated synchrotron nebulae, and show that the nebula spectra would show a significant hump in several decades near the self-absorption frequency. Identifying such a spectral feature would reveal an embedded FRB in a synchrotron nebula.« less

Dispersion, Mixing, and Combustion in Turbulent and High-Speed Flows, Air-Breathing Propulsion, and Hypersonic Flight

DTIC Science & Technology

2010-03-31

postdoctoral research of Antonino Ferrante (currently Assistant Professor at the University of Washington). The fluid dynamics video "LES of an inclined jet...Northrop Professor of Aeronautics and Professor of Applied Physics, Caltech, and ChiefTechnologist, JPL. Ferrante, Antonino : Postdoctoral Scholar in

JPL Non-NASA Programs

NASA Technical Reports Server (NTRS)

Cox, Robert S.

2006-01-01

A viewgraph presentation describing JPL's non-NASA Programs is shown. The contents include: 1) JPL/Caltech: National Security Heritage; 2) Organization and Portfolio; 3) Synergistic Areas of Interest; 4) Business Environment; 5) National Space Community; 6) New Business Environment; 7) Technology Transfer Techniques; 8) Innovative Partnership Program (IPP); and 9) JPL's Track Record.

Micro Power

DTIC Science & Technology

2004-02-01

GENERATOR ENERGIZED BY A MEMS BASED CHEMICAL- THERMAL REACTOR” 5-6 PI: Professor Robert F. Savinell Co-I(s): Professors C. C. Liu, M. H . Litt, and J. S...January 8, 2002 PI Chih-Ming Ho UCLA Yu-Chong Tai Caltech Siegfried Janson Henry Helvajian Aerospace Corporation H.Q. Yang Andrzej J. Przekwasa CFDRC Co

Food Production, Population Growth, and Environmental Quality. Caltech Population Program Occasional Papers, Series 1, Number 7.

ERIC Educational Resources Information Center

Groth, Edward, III

This paper, one in a series of occasional publications, discusses trends in food production and population growth, emphasizing how environmental quality will be affected. The series is intended to increase understanding of the interrelationships between population growth and socioeconomic and cultural patterns throughout the world, and to…

Angles and Range: Initial Orbital Determination with the Air Force Space Surveillance Telescope (AFSST)

DTIC Science & Technology

2008-09-01

Tycho-2 [12], UCAC-2 [8], USNO-B1.0 [7] supplemented with data from 2MASS [13]. The final intrinsic issue is whether terrestrial parallax...www.ipac.caltech.edu/ 2mass /releases/allsky/ [14] Strand, K. Aa. 1963, “Trigonometric Parallaxes” in Basic Astronomical Data (University of Chicago

China's Population Program at the Grassroots Level: Report on a Field Trip, Summer 1972.

ERIC Educational Resources Information Center

Chen, Pi-chao

The goals of the Caltech Population Program are to increase understanding of the interrelationships between population growth and socioeconomic and cultural patterns throughout the world and to communicate this understanding. This series of occasional papers is one step in the process of communicating research results. The papers deal primarily…

Genesis of "Biochemistry: A Problems Approach"

ERIC Educational Resources Information Center

Wood, William B.

2002-01-01

When the author began teaching as a young assistant professor at Caltech in 1966, his assignment was to take over the undergraduate biochemistry course taught for many years by Henry Borsook, who was about to retire. Students dreaded this course. Having delighted in biochemistry during his graduate training at Stanford, he was determined to put…

Visual word ambiguity.

PubMed

van Gemert, Jan C; Veenman, Cor J; Smeulders, Arnold W M; Geusebroek, Jan-Mark

2010-07-01

This paper studies automatic image classification by modeling soft assignment in the popular codebook model. The codebook model describes an image as a bag of discrete visual words selected from a vocabulary, where the frequency distributions of visual words in an image allow classification. One inherent component of the codebook model is the assignment of discrete visual words to continuous image features. Despite the clear mismatch of this hard assignment with the nature of continuous features, the approach has been successfully applied for some years. In this paper, we investigate four types of soft assignment of visual words to image features. We demonstrate that explicitly modeling visual word assignment ambiguity improves classification performance compared to the hard assignment of the traditional codebook model. The traditional codebook model is compared against our method for five well-known data sets: 15 natural scenes, Caltech-101, Caltech-256, and Pascal VOC 2007/2008. We demonstrate that large codebook vocabulary sizes completely deteriorate the performance of the traditional model, whereas the proposed model performs consistently. Moreover, we show that our method profits in high-dimensional feature spaces and reaps higher benefits when increasing the number of image categories.

A comparison of two cloudwater/fogwater collectors: The rotating arm collector and the caltech active strand cloudwater collector

NASA Astrophysics Data System (ADS)

Collett, Jeffrey L.; Daube, Bruce C.; Munger, J. William; Hoffmann, Michael R.

A side-by-side comparison of the Rotating Arm Collector (RAC) and the Caltech Active Strand Cloudwater Collector (CASCC) was conducted at an elevated coastal site near the eastern end of the Santa Barbara Channel in southern California. The CASCC was observed to collect cloudwater at rates of up to 8.5 ml min -1. The ratio of cloudwater collection rates was found to be close to the theoretical prediction of 4.2:1 (CASCC:RAC) over a wide range of liquid water contents (LWC). At low LWC, however, this ratio climbed rapidly, possibly reflecting a predominance of small droplets under these conditions, coupled with a greater collection efficiency of small droplets by the CASCC. Cloudwater samples collected by the RAC had significantly higher concentrations of Na +, Ca 2+, Mg 2+ and Cl - than those collected by the CASCC. These higher concentrations may be due to differences in the chemical composition of large vs small droplets. No significant differences were observed in concentrations of NO 3-, SO 42- or NH 4+ in samples collected by the two instruments.

Vertical columns of NO2, HONO, HCHO, CHOCHO and aerosol extinction: diurnal and seasonal variations in context of CalNex and CARES

NASA Astrophysics Data System (ADS)

Ortega, I.; Coburn, S.; Oetjen, H.; Sinreich, R.; Thalman, R. M.; Waxman, E.; Volkamer, R.

2011-12-01

We present results from two ground-based University of Colorado Multi Axis Differential Optical Absorption Spectroscopy (CU-MAX-DOAS) instruments that were deployed during the CALNEX and CARES 2010 field campaigns. Ground based CU-MAX-DOAS measurements were carried out through Dec 2010, and measured vertical column abundances of nitrogen dioxide (NO2), nitrous acid (HONO), formaldehyde (HCHO), glyoxal (CHOCHO), and aerosol extinction, which is determined indirectly from observing the oxygen dimers (O4). The measurements were acquired on the top of Millikan library at Caltech, Pasadena, CA, at the Fontana Arrows site located 60 Km east of Caltech, and for a limited period also downwind of Sacramento at T1 site during CARES. In the South Coast Air Basin, the MAX-DOAS instruments at both sites collected an extended time series of use to test satellites, and atmospheric chemistry models. We determine the state of the planetary boundary layer by comparing the columns observations with in-situ sensors, and place the CALNEX and CARES measurements intensive into seasonal context.

Tier-scalable reconnaissance: the future in autonomous C4ISR systems has arrived: progress towards an outdoor testbed

NASA Astrophysics Data System (ADS)

Fink, Wolfgang; Brooks, Alexander J.-W.; Tarbell, Mark A.; Dohm, James M.

2017-05-01

Autonomous reconnaissance missions are called for in extreme environments, as well as in potentially hazardous (e.g., the theatre, disaster-stricken areas, etc.) or inaccessible operational areas (e.g., planetary surfaces, space). Such future missions will require increasing degrees of operational autonomy, especially when following up on transient events. Operational autonomy encompasses: (1) Automatic characterization of operational areas from different vantages (i.e., spaceborne, airborne, surface, subsurface); (2) automatic sensor deployment and data gathering; (3) automatic feature extraction including anomaly detection and region-of-interest identification; (4) automatic target prediction and prioritization; (5) and subsequent automatic (re-)deployment and navigation of robotic agents. This paper reports on progress towards several aspects of autonomous C4ISR systems, including: Caltech-patented and NASA award-winning multi-tiered mission paradigm, robotic platform development (air, ground, water-based), robotic behavior motifs as the building blocks for autonomous tele-commanding, and autonomous decision making based on a Caltech-patented framework comprising sensor-data-fusion (feature-vectors), anomaly detection (clustering and principal component analysis), and target prioritization (hypothetical probing).

Synchrotron Radiation from Ultra-High Energy Protons and the Fermi Observations of GRB 080916C

DTIC Science & Technology

2010-01-01

compared with keV – MeV radiation. Here we show that synchrotron radiation from cosmic ray protons accelerated in GRBs, delayed by the proton synchrotron... cosmic rays from sources within 100 Mpc for nano-Gauss intergalactic magnetic fields. The total energy requirements in a proton synchrotron model are...component arising from cosmic - ray proton synchrotron radiation explains the delayed onset of the LAT emission. If GRBs accelerate UHECRs, then the

Contributed Review: Absolute spectral radiance calibration of fiber-optic shock-temperature pyrometers using a coiled-coil irradiance standard lamp

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fat’yanov, O. V., E-mail: fatyan1@gps.caltech.edu; Asimow, P. D., E-mail: asimow@gps.caltech.edu

2015-10-15

We describe an accurate and precise calibration procedure for multichannel optical pyrometers such as the 6-channel, 3-ns temporal resolution instrument used in the Caltech experimental geophysics laboratory. We begin with a review of calibration sources for shock temperatures in the 3000-30 000 K range. High-power, coiled tungsten halogen standards of spectral irradiance appear to be the only practical alternative to NIST-traceable tungsten ribbon lamps, which are no longer available with large enough calibrated area. However, non-uniform radiance complicates the use of such coiled lamps for reliable and reproducible calibration of pyrometers that employ imaging or relay optics. Careful analysis of documentedmore » methods of shock pyrometer calibration to coiled irradiance standard lamps shows that only one technique, not directly applicable in our case, is free of major radiometric errors. We provide a detailed description of the modified Caltech pyrometer instrument and a procedure for its absolute spectral radiance calibration, accurate to ±5%. We employ a designated central area of a 0.7× demagnified image of a coiled-coil tungsten halogen lamp filament, cross-calibrated against a NIST-traceable tungsten ribbon lamp. We give the results of the cross-calibration along with descriptions of the optical arrangement, data acquisition, and processing. We describe a procedure to characterize the difference between the static and dynamic response of amplified photodetectors, allowing time-dependent photodiode correction factors for spectral radiance histories from shock experiments. We validate correct operation of the modified Caltech pyrometer with actual shock temperature experiments on single-crystal NaCl and MgO and obtain very good agreement with the literature data for these substances. We conclude with a summary of the most essential requirements for error-free calibration of a fiber-optic shock-temperature pyrometer using a high-power coiled tungsten halogen irradiance standard lamp.« less

Developing an Education and Public Outreach (EPO) program for the Caltech Tectonics Observatory

NASA Astrophysics Data System (ADS)

Kovalenko, L.; Nadin, E.; Avouac, J.

2008-12-01

The Caltech Tectonics Observatory (TO) is an interdisciplinary center, focused on geological processes occurring at the boundaries of Earth's tectonic plates. The timescales of these processes span from a few tens of seconds (the typical duration of an earthquake) to tens of millions of years (the time it takes to build mountains). Over the past four years, the TO has brought together 15 Caltech faculty from different fields, several visiting scientists from around the globe, and a few tens of graduate students and postdoctoral students, collaborating on scientific projects. A major objective of the TO now is to develop an Education and Public Outreach (EPO) program. Our goals are to (1) stimulate the interest of students and the general public in Earth Sciences, particularly in the study of tectonic processes, (2) inform and educate the general public about TO discoveries and advancements, and (3) make available the data and techniques developed by the TO for use in classrooms of all levels. To this effect, we have been developing our website for accessibility by the general public and writing educational web articles on TO research. A recent well-visited example is "The science behind the recent 2008 earthquake in China." We distribute animations that illustrate the mechanisms of earthquakes and tsunamis, and the various techniques used by TO scientists in their scientific investigations. The TO website also provides access to geodetic data collected by TO instruments and to the source models of recent large earthquakes as analyzed by TO scientists. The TO hosts tours of its facilities for local elementary school students and is working on developing education modules for high school and undergraduate classes. We are now working on a plan to offer short courses over the summer for undergraduate and graduate students in other institutions, in order to train them to analyze a variety of data and use techniques developed by TO scientists.

A portable FTS measurements during GOSAT and OCO-2 joint campaign in Western US 2017

NASA Astrophysics Data System (ADS)

Shiomi, K.; Kikuchi, N.; Kuze, A.; Hashimoto, M.; Suto, H.; Kataoka, F.; Kasai, K.; Arai, T.; Oshio, H.; Ohyama, H.; Morino, I.; Hori, A.; Hedelius, J.; Parker, H. A.; Roehl, C. M.; Wennberg, P. O.; Leifer, I.; Iraci, L. T.; Bruegge, C. J.; Schwandner, F. M.; Osterman, G. B.; Crisp, D.

2017-12-01

The column-average dry air mole fractions of carbon dioxide (XCO2), methane (XCH4) and carbon monoxide (XCO) were measured from the surface using direct sunlight at near-IR wavelengths. Simultaneous detection of CO is helpful to characterize CO2 source type. We measured XCO along with XCO2 and XCH4 using an upgraded portable Fourier transform spectrometer (FTS), EM27/SUN, in western US field experiments at 1) Caltech and JPL, in Pasadena, a northern Los Angeles suburb, 2) Railroad Valley (RRV), a desert playa in Nevada, and 3) Salton Sea, a terminal high-salinity lake in southern California's Imperial Valley. These measurements were conducted during the GOSAT/OCO-2 joint campaign in the early summer of 2017. Before and after US shipments, the JAXA EM27 was compared with the NIES EM27 and Tsukuba TCCON station to quantify the measurement bias and to identify any unanticipated changes. After US shipment, the JAXA EM27 was compared with the Caltech EM27 and the Caltech TCCON station with the NASA-Dryden TCCON station, which is now located at JPL for OCO-3 pre-flight test comparisons. At RRV, we obtained not only the EM27 data but also atmospheric profile of pressure, temperature and humidity by radiosonde and aerosol optical thickness (AOT) by Microtops. Then, we deployed the EM27 on the south side of the Salton Sea, where agriculture, active volcanism and geothermal power plants might produce CO2 and CH4 as sources. A large CO enhancement originating from wildfires was serendipitously measured in conjunction with a large AOT measured by the Microtops. The JAXA EM27 measurements at Pasadena, RRV and Salton Sea were taken in conjunction with GOSAT and OCO-2 overpass targets and are being used to assess the value of the EM27 as a portable transfer standard for validating space based measurements of greenhouse gases.

X-ray absorption fine structure (XAFS) spectroscopy using synchrotron radiation

NASA Astrophysics Data System (ADS)

Shrivastava, B. D.

2012-05-01

The X-ray absorption fine structure (XAFS) spectra are best recorded when a highly intense beam of X-rays from a synchrotron is used along with a good resolution double crystal or curved crystal spectrometer and detectors like ionization chambers, scintillation counters, solid state detectors etc. Several synchrotrons around the world have X-ray beamlines dedicated specifically to XAFS spectroscopy. Fortunately, the Indian synchrotron (Indus-2) at Raja Ramanna Centre for Advanced Technology (RRCAT) at Indore has started operation. A dispersive type EXAFS beamline called BL-8 has been commissioned at this synchrotron and another beamline having double crystal monochromator (DCM) is going to be commissioned shortly. In Indian context, in order that more research workers use these beamlines, the study of XAFS spectroscopy using synchrotron radiation becomes important. In the present work some of the works done by our group on XAFS spectroscopy using synchrotron radiation have been described.

Scientific Integrity and Executive National Security Proclamations: A Conflict of the Modern Age

NASA Astrophysics Data System (ADS)

Nelson, R.; Banerdt, B.; Bell, J. L.; Byrnes, D. V.; Carlisle, G. L.; D'Addario, L. R.; Weissman, P. R.; Eisenhardt, P. R.; Foster, S. D.; Golombek, M. P.; Gorjian, V.; Gorjian, Z.; Hale, A. S.; Kulleck, J. G.; Laubach, S. L.; McElrath, T. P.; Penanen, K. I.; Satter, C.; Walker, W. J.

2010-12-01

In 2004, in response to the events of September, 11, 2001, President George W. Bush issued Homeland Security Presidential Directive #12, an executive order requiring a uniform means of identification (i.e. identification badge) for all employees and contractors at federal facilities. To comply with this directive NASA ordered that its contract employees at the Jet Propulsion Laboratory 'voluntarily' agree to an open ended, unrestricted, background investigation into the intimate details of their private lives. These employees do not have security clearances and do not work with classified material. Caltech, which employs the JPL personnel under a NASA management contract, informed the employees that if they did not ‘voluntarily’ consent to the background investigation, they would be assumed to have voluntarily resigned and therefore be denied access to JPL (i.e. they would be functionally terminated). In October 2007, twentyeight JPL employees filed suit in Federal District Court. After an initial dismissal by the lowest federal court, the Ninth Circuit Court of Appeals issued an injunction against Caltech and NASA, stopping the background investigations. The Appeals Court found that the investigations were not narrowly tailored to meet the specific needs of NASA and therefore violated the employee’s legitimate expectation of informational privacy. This injunction has been reviewed and upheld several times by various panels of the Ninth Circuit Court of Appeals. In November 2009, the United States Department of Justice petitioned the U.S. Supreme Court requesting that it overturn this injunction. The Supreme Court accepted the case for oral arguments and scheduled them for October 5, 2010. A decision is imminent (if it has not been made already). The case has opened the following questions regarding all research workers under government contract: 1. What impact would such intrusive investigations have on open scientific inquiry and scientific integrity? 2. How much can the Government reasonably ask about the backgrounds of its contract employees? 3. What rights do employees have to challenge the findings of their background investigations, and can the results of such investigations be contested in the courts? 4. What is the responsibility of a contract employer such as Caltech to protect the privacy of contract research workers like those at JPL? 5. What is the responsibility of professional societies in representing the interests of federal contract employees such as those at JPL? 6. What would constitute a reasonable background investigation of contract employees that would be narrowly tailored in order to protect informational privacy? This work is a private venture. Affiliations are listed for identification purposes only. No NASA, Caltech or JPL resources were expended in producing this abstract.

Support for Synchrotron Access by Environmental Scientists

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daly, Michael; Madden, Andrew; Palumbo, Anthony

2006-06-01

To support ERSP-funded scientists in all aspects of synchrotron-based research at the Advanced Photon Source (APS). This support comes in one or more of the following forms: (1) writing proposals to the APS General User (GU) program, (2) providing time at MRCAT/EnviroCAT beamlines via the membership of the Molecular Environmental Science (MES) Group in MRCAT/EnviroCAT, (3) assistance in experimental design and sample preparation, (4) support at the beamline during the synchrotron experiment, (5) analysis and interpretation of the synchrotron data, and (6) integration of synchrotron experimental results into manuscripts.

A compact high brightness laser synchrotron light source for medical applications

NASA Astrophysics Data System (ADS)

Nakajima, Kazuhisa

1999-07-01

The present high-brightness hard X-ray sources have been developed as third generation synchrotron light sources based on large high energy electron storage rings and magnetic undulators. Recently availability of compact terawatt lasers arouses a great interest in the use of lasers as undulators. The laser undulator concept makes it possible to construct an attractive compact synchrotron radiation source which has been proposed as a laser synchrotron light source. This paper proposes a compact laser synchrotron light source for mediacal applications, such as an intravenous coronary angiography and microbeam therapy.

The uses of synchrotron radiation sources for elemental and chemical microanalysis

USGS Publications Warehouse

Chen, J.R.; Chao, E.C.T.; Minkin, J.A.; Back, J.M.; Jones, K.W.; Rivers, M.L.; Sutton, S.R.

1990-01-01

Synchrotron radiation sources offer important features for the analysis of a material. Among these features is the ability to determine both the elemental composition of the material and the chemical state of its elements. For microscopic analysis synchrotron X-ray fluorescence (SXRF) microprobes now offer spatial resolutions of 10 ??m with minimum detection limits in the 1-10 ppm range depending on the nature of the sample and the synchrotron source used. This paper describes the properties of synchrotron radiation and their importance for elemental analysis, existing synchrotron facilities and those under construction that are optimum for SXRF microanalysis, and a number of applications including the high energy excitation of the K lines of heavy elements, microtomography, and XANES and EXAFS spectroscopies. ?? 1990.

Charles F. Richter; an interview

USGS Publications Warehouse

Spall, H.

1980-01-01

Charles F. Richter, renowned seismologist, is a professor emeritus at the California Institue of techonology (Caltech). He is best known to the public for the Richter magnitude scale; but he is equally recognized in the scientific community for many other contributions to seismology including his books Elementary Seismology (1958) and Seismicity of the Earth (coauthored in 1954 with Beno Gutenberg). 

Deflection Measurements on Propeller 5503 in Ahead and Crashback

DTIC Science & Technology

2016-10-01

the dots on the blade that were visible for the run . Not all points could be determined for each picture during each run . One issue discovered with...Channel (LCC) in February and April of 2009. The deflection of the blades was measured using defocused particle image velocimetry. Comparisons were made... Blade Deflection Measurement CalTech

John Todd--Numerical Mathematics Pioneer

ERIC Educational Resources Information Center

Albers, Don

2007-01-01

John Todd, now in his mid-90s, began his career as a pure mathematician, but World War II interrupted that. In this interview, he talks about his education, the significant developments in his becoming a numerical analyst, and the journey that concluded at Caltech. Among the interesting stories are how he met his wife-to-be the mathematician Olga…

Demographic Trends in the Republic of Zaire. Caltech Population Program Occasional Papers, Series 1, Number 5.

ERIC Educational Resources Information Center

Boute, Joseph

This paper, one in a series of occasional publications, discusses population growth and trends in the African Republic of Zaire. The series is intended to increase understanding of the interrelationships between population growth and socioeconomic and cultural patterns throughout the world, and to communicate this understanding to scholars and…

Synchroton and Simulations Techniques Applied to Problems in Materials Science: Catalysts and Azul Maya Pigments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chianelli, R.

2005-01-12

Development of synchrotron techniques for the determination of the structure of disordered, amorphous and surface materials has exploded over the past twenty years due to the increasing availability of high flux synchrotron radiation and the continuing development of increasingly powerful synchrotron techniques. These techniques are available to materials scientists who are not necessarily synchrotron scientists through interaction with effective user communities that exist at synchrotrons such as the Stanford Synchrotron Radiation Laboratory (SSRL). In this article we review the application of multiple synchrotron characterization techniques to two classes of materials defined as ''surface compounds.'' One class of surface compounds aremore » materials like MoS{sub 2-x}C{sub x} that are widely used petroleum catalysts used to improve the environmental properties of transportation fuels. These compounds may be viewed as ''sulfide supported carbides'' in their catalytically active states. The second class of ''surface compounds'' is the ''Maya Blue'' pigments that are based on technology created by the ancient Maya. These compounds are organic/inorganic ''surface complexes'' consisting of the dye indigo and palygorskite, a common clay. The identification of both surface compounds relies on the application of synchrotron techniques as described in this report.« less

Proceedings of the XIII International School and Symposium on Synchrotron Radiation in Natural Science 2016, Ustroń-Jaszowiec, Poland

NASA Astrophysics Data System (ADS)

Kozak, Maciej; Kwiatek, Wojciech M.; Piszora, Paweł

2017-11-01

This special issue of Nuclear Instruments and Methods in Physics Research Section B of Nuclear Instruments and Methods in Physics Research was prepared to present recent achievements in synchrotron radiation science and mark the 25th anniversary of the Polish Synchrotron Radiation Society (PSRS) which fell in 2016. It presents selected papers submitted after the 13th International School and Symposium on Synchrotron Radiation in Natural Science (ISSRNS 2016) which was organized by PSRS in cooperation with the Adam Mickiewicz University. It is worth noting that PSRS is probably one of the earliest founded scientific societies focused on promoting the use of synchrotron radiation research (for details visit the PSRS home page: http://www.synchrotron.org.pl.

Protein Data Bank depositions from synchrotron sources.

PubMed

Jiang, Jiansheng; Sweet, Robert M

2004-07-01

A survey and analysis of Protein Data Bank (PDB) depositions from international synchrotron radiation facilities, based on the latest released PDB entries, are reported. The results (http://asdp.bnl.gov/asda/Libraries/) show that worldwide, every year since 1999, more than 50% of the deposited X-ray structures have used synchrotron facilities, reaching 75% by 2003. In this web-based database, all PDB entries among individual synchrotron beamlines are archived, synchronized with the weekly PDB release. Statistics regarding the quality of experimental data and the refined model for all structures are presented, and these are analysed to reflect the impact of synchrotron sources. The results confirm the common impression that synchrotron sources extend the size of structures that can be solved with equivalent or better quality than home sources.

Impact of synchrotron radiation on macromolecular crystallography: a personal view

PubMed Central

Dauter, Zbigniew; Jaskolski, Mariusz; Wlodawer, Alexander

2010-01-01

The introduction of synchrotron radiation sources almost four decades ago has led to a revolutionary change in the way that diffraction data from macromolecular crystals are being collected. Here a brief history of the development of methodologies that took advantage of the availability of synchrotron sources are presented, and some personal experiences with the utilization of synchrotrons in the early days are recalled. PMID:20567074

Galactic synchrotron radiation from radio to microwaves, and its relation to cosmic-ray propagation models: past, present and future

NASA Astrophysics Data System (ADS)

Orlando, Elena

2016-04-01

Galactic synchrotron radiation observed from radio to microwaves is produced by cosmic-ray (CR) electrons propagating in magnetic fields (B-fields). The low-frequency foreground component separated maps by WMAP and Planck depend on the assumed synchrotron spectrum. The synchrotron spectrum varies for different line of sights as a result of changes on the CR spectrum due to propagation effects and source distributions. Our present knowledge of the CR spectrum at different locations in the Galaxy is not sufficient to distinguish various possibilities in the modeling. As a consequence uncertainties on synchrotron emission models complicate the foreground component separation analysis with Planck and future microwave telescopes. Hence, any advancement in synchrotron modeling is important for separating the different foreground components.The first step towards a more comprehensive understanding of degeneracy and correlation among the synchrotron model parameters is outlined in our Strong et al. 2011 and Orlando et al. 2013 papers. In the latter the conclusion was that CR spectrum, propagation models, B-fields, and foreground component separation analysis need to be studied simultaneously in order to properly obtain and interpret the synchrotron foreground. Indeed for the officially released Planck maps, we use only the best spectral model from our above paper for the component separation analysis.Here we present a collections of our latest results on synchrotron, CRs and B-fields in the context of CR propagation, showing also our recent work on B-fields within the Planck Collaboration. We underline also the importance of using the constraints on CRs that we obtain from gamma ray observations. Methods and perspectives for further studies on the synchrotron foreground will be addressed.

Comments on Landau damping due to synchrotron frequency spread

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ng, K.Y.; /Fermilab

2005-01-01

An inductive/space-charge impedance shifts the synchrotron frequency downwards above/below transition, but it is often said that the coherent synchrotron frequency of the bunch is not shifted in the rigid-dipole mode. On the other hand, the incoherent synchrotron frequency due to the sinusoidal rf always spreads in the downward direction. This spread will therefore not be able to cover the coherent synchrotron frequency, implying that there will not be any Landau damping no matter how large the frequency spread is. By studying the dispersion relation, it is shown that the above argument is incorrect, and there will be Landau damping ifmore » there is sufficient frequency spread. The main reason is that the coherent frequency of the rigid-dipole mode will no longer remain unshifted in the presence of a synchrotron frequency spread.« less

Synchrotron radiation laboratories at the Bonn electron accelerators. a status report

NASA Astrophysics Data System (ADS)

Hormes, J.

1987-07-01

At the Physikalisches Institut of the University in Bonn experiments with synchrotron radiation were carried out ever since 1962. At the moment (June 1986) all work takes place in the SR-laboratory at the 2.5 GeV synchrotron. A 3.5 GeV stretcher ring (ELSA) is under construction and will come into operation at the end of 1986. This accelerator will also run as a storage ring for synchrotron radiation experiments and a laboratory to be used at this machine is also under consideration. The SR experiments which are carried out in Bonn try to take advantage of the fact that we are still using a high energy synchrotron for our work. Besides basic research also applied work is done using synchrotron radiation even as a production tool for X-ray lithography.

Plant-based Food and Feed Protein Structure Changes Induced by Gene-transformation heating and bio-ethanol processing: A Synchrotron-based Molecular Structure and Nutrition Research Program

DOE Office of Scientific and Technical Information (OSTI.GOV)

P Yu

Unlike traditional 'wet' analytical methods which during processing for analysis often result in destruction or alteration of the intrinsic protein structures, advanced synchrotron radiation-based Fourier transform infrared microspectroscopy has been developed as a rapid and nondestructive and bioanalytical technique. This cutting-edge synchrotron-based bioanalytical technology, taking advantages of synchrotron light brightness (million times brighter than sun), is capable of exploring the molecular chemistry or structure of a biological tissue without destruction inherent structures at ultra-spatial resolutions. In this article, a novel approach is introduced to show the potential of the advanced synchrotron-based analytical technology, which can be used to study plant-basedmore » food or feed protein molecular structure in relation to nutrient utilization and availability. Recent progress was reported on using synchrotron-based bioanalytical technique synchrotron radiation-based Fourier transform infrared microspectroscopy and diffused reflectance infrared Fourier transform spectroscopy to detect the effects of gene-transformation (Application 1), autoclaving (Application 2), and bio-ethanol processing (Application 3) on plant-based food and feed protein structure changes on a molecular basis. The synchrotron-based technology provides a new approach for plant-based protein structure research at ultra-spatial resolutions at cellular and molecular levels.« less

Synchrotron X-Ray Diffraction Analysis of Meteorites in Thin Section: Preliminary Results

NASA Technical Reports Server (NTRS)

Treiman, A. H.; Lanzirotti, A.; Xirouchakis, D.

2004-01-01

X-ray diffraction is the pre-eminent technique for mineral identification and structure determination, but is difficult to apply to grains in thin section, the standard meteorite preparation. Bright focused X-ray beams from synchrotrons have been used extensively in mineralogy and have been applied to extraterrestrial particles. The intensity and small spot size achievable in synchrotron X-ray beams makes them useful for study of materials in thin sections. Here, we describe Synchrotron X-ray Diffraction (SXRD) in thin section as done at the National Synchrotron Light Source, and cite examples of its value for studies of meteorites in thin section.

The International GPS Network for Charting the Evolving Global Reference Frame

NASA Technical Reports Server (NTRS)

Zumberge, J. F.; Heflin, M. B.; Lindqwister, U. J.; Neilan, R. E.; Watkins, M. M.

1995-01-01

The Telecommunications and Engineering Division of Caltech's Jet Propulsion Laboratory is funded by the National Aeronautics and Space Administration to play a variety of roles in applying the Global Positioning System (GPS) to geodesy and geodynamics. Among these are the operation of dozens of globally-distributed, permanently-operating Earth fixed GPS stations. This, and other applications are described.

Impact Cratering Physics al Large Planetary Scales

NASA Astrophysics Data System (ADS)

Ahrens, Thomas J.

2007-06-01

Present understanding of the physics controlling formation of ˜10^3 km diameter, multi-ringed impact structures on planets were derived from the ideas of Scripps oceanographer, W. Van Dorn, University of London's, W, Murray, and, Caltech's, D. O'Keefe who modeled the vertical oscillations (gravity and elasticity restoring forces) of shock-induced melt and damaged rock within the transient crater immediately after the downward propagating hemispheric shock has processed rock (both lining, and substantially below, the transient cavity crater). The resulting very large surface wave displacements produce the characteristic concentric, multi-ringed basins, as stored energy is radiated away and also dissipated upon inducing further cracking. Initial calculational description, of the above oscillation scenario, has focused upon on properly predicting the resulting density of cracks, and, their orientations. A new numerical version of the Ashby--Sammis crack damage model is coupled to an existing shock hydrodynamics code to predict impact induced damage distributions in a series of 15--70 cm rock targets from high speed impact experiments for a range of impactor type and velocity. These are compared to results of crack damage distributions induced in crustal rocks with small arms impactors and mapped ultrasonically in recent Caltech experiments (Ai and Ahrens, 2006).

A Low Noise NbTiN-Based 850 GHz SIS Receiver for the Caltech Submillimeter Observatory

NASA Technical Reports Server (NTRS)

Kooi, J. W.; Kawamura, J.; Chen, J.; Chattopadhyay, G.; Pardo, J. R.; Zmuidzinas, J.; Phillips, T. G.; Bumble, B.; Stern, J.; LeDuc, H. G.

2000-01-01

We have developed a niobium titanium nitride (NbTiN) based superconductor- insulator-superconductor (SIS) receiver to cover the 350 micron atmospheric window. This frequency band lies entirely above the energy gap of niobium (700 GHz), a commonly used SIS superconductor. The instrument uses an open structure twin-slot SIS mixer that consists of two Nb/AlN/NbTiN tunnel junctions, NbTiN thin-film microstrip tuning elements, and a NbTiN ground plane. The optical configuration is very similar to the 850 GHz waveguide receiver that was installed at the Caltech Submillimeter Observatory (CSO) in 1997. To minimize front-end loss, we employed reflecting optics and a cooled beamsplitter at 4 K. The instrument has an uncorrected receiver noise temperature of 205K DSB at 800 GHz and 410K DSB at 900 GHz. The degradation in receiver sensitivity with frequency is primarily due to an increase in the mixer conversion loss, which is attributed to the mismatch between the SIS junction and the twin-slot antenna impedance. The overall system performance has been confirmed through its use at the telescope to detect a wealth of new spectroscopic lines.

The earthshine s spectra

NASA Astrophysics Data System (ADS)

Montanes Rodriguez, P.; Palle, E.; Goode, P.; Koonin, S.; Hickey, J.; Qiu, J.; Yurchysyn, V.

The Earthshine project, was run by California Institute of Technology (Caltech) between 1993 and 1995. Since 1998, it has been a collaborative effort between Caltech and Big Bear Solar Observatory (BBSO)/New Jersey Institute of Technology (NJIT). Our primary goal is the precise determination of a global and absolutely calibrated Earth's albedo and its synoptic, seasonal, and annual variability; as well as the measurement and investigation of the resolved reflected spectrum of the integrated Earth in the infrared region. The absorption in the infrared region, mainly due to rotational and vibrational transitions of the molecules, show the absorption bands of various telluric and solar components allowing the analysis of the Earth's spectrum such as it would be observed from the outer space. In this paper we present preliminary results of spectroscopic observations, made at Palomar Observatory with the 60-inch telescope's echelle spectrograph. They targeted the visible and near infrared region of the electromagnetic spectrum, and were performed in the spectral range (< 1μm) of the bands of Oxygen A, Oxygen B, water and Hydrogen alpha (H). The first three are typically terrestrial molecular bands. The fourth line, H, is a solar line, used mainly for spectral calibration.

Herschel Observations of C+ in the Vicinity of Star Forming Complexes in the Galactic Plane

NASA Astrophysics Data System (ADS)

Pineda, Jorge; Velusamy, T.; Langer, W.; Goldsmith, P.; Li, D.; Yorke, H.

2010-05-01

The CII fine-structure line at 158 um, is an excellent tracer of the warm diffuse gas and the hot, dense Photon Dominated Regions (PDRs). We can, therefore, use the CII emission as a probe to understand the effects of star formation on their interstellar environment. Here we present the first results from the Galactic Observations of Terahertz C+ (GOT C+), a Herschel Key Project study of CII fine structure emission in the vicinity of star forming complexes. In the Priority Science Phase of HIFI observations, the GOT C+ project collects data along a dozen lines of sight passing near star forming regions in the inner Galaxy from longitude 310 degrees to 25 degrees. We discuss our first results on the transition between dense and hot gas (traced by CII) and dense and cold gas (traced by 12CO and 13CO). This research was conducted at the Jet Propulsion Laboratory, California Institute of Technology under contract with the National Aeronautics and Space Administration. JLP was supported under the NASA Postdoctoral Program at JPL, Caltech, administered by Oak Ridge Associated Universities through a contract with NASA, and is currently supported as a Caltech-JPL Postdoc.

Numerical Study of High-Speed Droplet Impact on Surfaces and its Physical Cleaning Effects

NASA Astrophysics Data System (ADS)

Kondo, Tomoki; Ando, Keita

2015-11-01

Spurred by the demand for cleaning techniques of low environmental impact, one favors physical cleaning that does not rely on any chemicals. One of the promising candidates is based on water jets that often involve fission into droplet fragments and collide with target surfaces to which contaminant particles (often micron-sized or even smaller) stick. Hydrodynamic force (e.g., shearing and lifting) arising from the droplet impact will play a role to remove the particles, but its detailed mechanism is still unknown. To explore the role of high-speed droplet impact in physical cleaning, we solve compressible Navier-Stokes equations with a finite volume method that is designed to capture both shocks and material interfaces in accurate and robust manners. Water hammer and shear flow accompanied by high-speed droplet impact at a rigid wall is simulated to evaluate lifting force and rotating torque, which are relevant to the application of particle removal. For the simulation, we use the numerical code recently developed by Computational Flow Group lead by Tim Colonius at Caltech. The first author thanks Jomela Meng for her help in handling the code during his stay at Caltech.

Caltech water-ice dusty plasma: preliminary results

NASA Astrophysics Data System (ADS)

Bellan, Paul; Chai, Kilbyoung

2013-10-01

A water-ice dusty plasma laboratory experiment has begun operation at Caltech. As in Ref., a 1-5 watt parallel-plate 13.56 MHz rf discharge plasma has LN2-cooled electrodes that cool the neutral background gas to cryogenic temperatures. However, instead of creating water vapor by in-situ deuterium-oxygen bonding, here the neutral gas is argon and water vapor is added in a controlled fashion. Ice grains spontaneously form after a few seconds. Photography with a HeNe line filter of a sheet of HeNe laser light sheet illuminating a cross section of dust grains shows a large scale whorl pattern composed of concentric sub-whorls having wave-like spatially varying intensity. Each sub-whorl is composed of very evenly separated fine-scale stream-lines indicating that the ice grains move in self-organized lanes like automobiles on a multi-line highway. HeNe laser extinction together with an estimate of dust density from the intergrain spacing in photographs indicates a 5 micron nominal dust grain radius. HeNe laser diffraction patterns indicate the ice dust grains are large and ellipsoidal at low pressure (200 mT) but small and spheroidal at high pressure (>600 mT). Supported by USDOE.

Examining Returned Samples in their Collection Tubes Using Synchrotron Radiation-Based Techniques

NASA Astrophysics Data System (ADS)

Schoonen, M. A.; Hurowitz, J. A.; Thieme, J.; Dooryhee, E.; Fogelqvist, E.; Gregerson, J.; Farley, K. A.; Sherman, S.; Hill, J.

2018-04-01

Synchrotron radiation-based techniques can be leveraged for triaging and analysis of returned samples before unsealing collection tubes. Proof-of-concept measurements conducted at Brookhaven National Lab's National Synchrotron Light Source-II.

Mono-Energy Coronary Angiography with a Compact Synchrotron Source

NASA Astrophysics Data System (ADS)

Eggl, Elena; Mechlem, Korbinian; Braig, Eva; Kulpe, Stephanie; Dierolf, Martin; Günther, Benedikt; Achterhold, Klaus; Herzen, Julia; Gleich, Bernhard; Rummeny, Ernst; Noёl, Peter B.; Pfeiffer, Franz; Muenzel, Daniela

2017-02-01

X-ray coronary angiography is an invaluable tool for the diagnosis of coronary artery disease. However, the use of iodine-based contrast media can be contraindicated for patients who present with chronic renal insufficiency or with severe iodine allergy. These patients could benefit from a reduced contrast agent concentration, possibly achieved through application of a mono-energetic x-ray beam. While large-scale synchrotrons are impractical for daily clinical use, the technology of compact synchrotron sources strongly advanced during the last decade. Here we present a quantitative analysis of the benefits a compact synchrotron source can offer in coronary angiography. Simulated projection data from quasi-mono-energetic and conventional x-ray tube spectra is used for a CNR comparison. Results show that compact synchrotron spectra would allow for a significant reduction of contrast media. Experimentally, we demonstrate the feasibility of coronary angiography at the Munich Compact Light Source, the first commercial installation of a compact synchrotron source.

New theoretical results in synchrotron radiation

NASA Astrophysics Data System (ADS)

Bagrov, V. G.; Gitman, D. M.; Tlyachev, V. B.; Jarovoi, A. T.

2005-11-01

One of the remarkable features of the relativistic electron synchrotron radiation is its concentration in small angle Δ ≈ 1/γ (here γ-relativistic factor: γ = E/mc2, E energy, m electron rest mass, c light velocity) near rotation orbit plane [V.G. Bagrov, V.A. Bordovitsyn, V.G. Bulenok, V. Ya. Epp, Kinematical projection of pulsar synchrotron radiation profiles, in: Proceedings of IV ISTC Scientific Advisory Commitee Seminar on Basic Science in ISTC Aktivities, Akademgorodok, Novosibirsk, April 23 27, 2001, p. 293 300]. This theoretically predicted and experimentally confirmed feature is peculiar to total (spectrum summarized) radiating intensity. This angular distribution property has been supposed to be (at least qualitatively) conserved and for separate spectrum synchrotron radiation components. In the work of V.G. Bagrov, V.A. Bordovitsyn, V. Ch. Zhukovskii, Development of the theory of synchrotron radiation and related processes. Synchrotron source of JINR: the perspective of research, in: The Materials of the Second International Work Conference, Dubna, April 2 6, 2001, pp. 15 30 and in Angular dependence of synchrotron radiation intensity. http://lanl.arXiv.org/abs/physics/0209097, it is shown that the angular distribution of separate synchrotron radiation spectrum components demonstrates directly inverse tendency the angular distribution deconcentration relatively the orbit plane takes place with electron energy growth. The present work is devoted to detailed investigation of this situation. For exact quantitative estimation of angular concentration degree of synchrotron radiation the definition of radiation effective angle and deviation angle is proposed. For different polarization components of radiation the dependence of introduced characteristics was investigated as a functions of electron energy and number of spectrum component.

Single-bunch synchrotron shutter

DOEpatents

Norris, James R.; Tang, Jau-Huei; Chen, Lin; Thurnauer, Marion

1993-01-01

An apparatus for selecting a single synchrotron pulse from the millions of pulses provided per second from a synchrotron source includes a rotating spindle located in the path of the synchrotron pulses. The spindle has multiple faces of a highly reflective surface, and having a frequency of rotation f. A shutter is spaced from the spindle by a radius r, and has an open position and a closed position. The pulses from the synchrotron are reflected off the spindle to the shutter such that the speed s of the pulses at the shutter is governed by: s=4.times..pi..times.r.times.f. such that a single pulse is selected for transmission through an open position of the shutter.

Sample manipulation and data assembly for robust microcrystal synchrotron crystallography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guo, Gongrui; Fuchs, Martin R.; Shi, Wuxian

With the recent developments in microcrystal handling, synchrotron microdiffraction beamline instrumentation and data analysis, microcrystal crystallography with crystal sizes of less than 10 µm is appealing at synchrotrons. However, challenges remain in sample manipulation and data assembly for robust microcrystal synchrotron crystallography. Here, the development of micro-sized polyimide well-mounts for the manipulation of microcrystals of a few micrometres in size and the implementation of a robust data-analysis method for the assembly of rotational microdiffraction data sets from many microcrystals are described. Here, the method demonstrates that microcrystals may be routinely utilized for the acquisition and assembly of complete data setsmore » from synchrotron microdiffraction beamlines.« less

Sample manipulation and data assembly for robust microcrystal synchrotron crystallography

DOE PAGES

Guo, Gongrui; Fuchs, Martin R.; Shi, Wuxian; ...

2018-04-19

With the recent developments in microcrystal handling, synchrotron microdiffraction beamline instrumentation and data analysis, microcrystal crystallography with crystal sizes of less than 10 µm is appealing at synchrotrons. However, challenges remain in sample manipulation and data assembly for robust microcrystal synchrotron crystallography. Here, the development of micro-sized polyimide well-mounts for the manipulation of microcrystals of a few micrometres in size and the implementation of a robust data-analysis method for the assembly of rotational microdiffraction data sets from many microcrystals are described. Here, the method demonstrates that microcrystals may be routinely utilized for the acquisition and assembly of complete data setsmore » from synchrotron microdiffraction beamlines.« less

Lossy radial diffusion of relativistic Jovian electrons. [calculation of synchrotron radiation and electron radiation for Jupiter

NASA Technical Reports Server (NTRS)

Barbosa, D. D.; Coroniti, F. V.

1976-01-01

The radial diffusion equation with synchrotron losses was solved by the Laplace transform method for near-equatorially mirroring relativistic electrons. The evolution of a power law distribution function was found and the characteristics of synchrotron burn-off are stated in terms of explicit parameters for an arbitrary diffusion coefficient. Emissivity from the radiation belts of Jupiter was studied. Asymptotic forms for the distribution in the strong synchrotron loss regime are provided.

Synchrotron Radiation Sheds Fresh Light on Plant Research: The Use of Powerful Techniques to Probe Structure and Composition of Plants.

PubMed

Vijayan, Permual; Willick, Ian R; Lahlali, Rachid; Karunakaran, Chithra; Tanino, Karen K

2015-07-01

While synchrotron radiation is a powerful tool in material and biomedical sciences, it is still underutilized in plant research. This mini review attempts to introduce the potential of synchrotron-based spectroscopic and imaging methods and their applications to plant sciences. Synchrotron-based Fourier transform infrared spectroscopy, X-ray absorption and fluorescence techniques, and two- and three-dimensional imaging techniques are examined. We also discuss the limitations of synchrotron-based research in plant sciences, specifically the types of plant samples that can be used. Despite limitations, the unique features of synchrotron radiation such as high brightness, polarization and pulse properties offer great advantages over conventional spectroscopic and imaging tools and enable the correlation of the structure and chemical composition of plants with biochemical function. Modern detector technologies and experimental methodologies are thus enabling plant scientists to investigate aspects of plant sciences such as ultrafast kinetics of biochemical reactions, mineral uptake, transport and accumulation, and dynamics of cell wall structure and composition during environmental stress in unprecedented ways using synchrotron beamlines. The potential for the automation of some of these synchrotron technologies and their application to plant phenotyping is also discussed. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Signatures of Synchrotron: Low-cutoff X-ray emission and the hard X-ray spectrum of Cas A

NASA Astrophysics Data System (ADS)

Stage, Michael D.; Fedor, Emily Elizabeth; Martina-Hood, Hyourin

2018-06-01

In soft X-rays, bright, young Galactic remnants (Cas A, Kepler, Tycho, etc.) present thermal line emission and bremsstrahlung from ejecta, and synchrotron radiation from the shocks. Their hard X-ray spectra tend to be dominated by power-law sources. However, it can be non-trivial to discriminate between contributions from processes such as synchrotron and bremsstrahlung from nonthermally accelerated electrons, even though the energies of the electrons producing this radiation may be very different. Spatially-resolved spectroscopic analysis of 0.5-10 keV observations with, e.g., Chandracan provide leverage in identifying the processes and their locations. Previously, Stage & Allen (2006), Allen & Stage (2007) and Stage & Allen (2011) identified regions characterized by high-cutoff synchrotron radiation. Extrapolating synchrotron model fits to the emission in the Chandra band, they estimated the synchrotron contribution to the hard X-ray spectrum at about one-third the observed flux, fitting the balance with nonthermal bremsstrahlung emission produced by nonthermal electrons in the ejecta. Although it is unlikely this analysis missed regions of the highest-cutoff synchrotron emission, which supplies the bulk of the synchrotron above 15 keV, it may have missed regions of lower-cutoff emission, especially if they are near bright ejecta and the reverse shock. These regions cannot explain the emission at the highest energies (~50 keV), but may make significant contributions to the hard spectrum at lower energies (~10 keV). Using the technique described in Fedor, Martina-Hood & Stage (this meeting), we revisit the analysis to include regions that may be dominated by low-cutoff synchrotron, located in the interior of the remnant, and/or correlated with the reverse shock. Identifying X-ray emission from accelerated electrons associated with the reverse-shock would have important implications for synchrotron and non-thermal bremsstrahlung radiation above the 10 keV.

Image Halftoning Using Optimized Dot Diffusion

DTIC Science & Technology

1998-01-01

ppvnath@sys.caltech.edu ABSTRACT The dot diffusion method for digital halftoning has the advantage of parallelism unlike the error diffusion ...digital halftoning : ordered dither [1], error diffusion [2], neural-net based methods [8], and more recently direct binary search (DBS) [7]. Ordered...from periodic patterns. On the other hand error diffused halftones do not suffer from periodicity and offer blue noise characteristic [3] which is

(abstract) Absolute Flux Calibrations of Venus and Jupiter at 32 GHz

NASA Technical Reports Server (NTRS)

Gatti, Mark S.; Klein, Michael J.

1994-01-01

The microwave flux densities of Venus and Jupiter at 32 GHz have been measured using a calibration standard radio telescope system at the Owens Valley Radio Observatory (OVRO) during April and May of 1993. These measurements are part of a joint JPL/Caltech program to accurately calibrate a catalog of other radio sources using the two bright planets as flux standards.

Quantum Algorithms for Fermionic Quantum Field Theories

DTIC Science & Technology

2014-04-28

preskill@theory.caltech.edu 1 Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is...NAME OF RESPONSIBLE PERSON a. REPORT unclassified b. ABSTRACT unclassified c. THIS PAGE unclassified Standard Form 298 (Rev. 8-98...operators of momentum modes. (The choice between these forms of measurement depends on the application.) 2.3 Complexity In this section we bound the

A Treasure Trove of Planets Found

NASA Image and Video Library

2017-02-28

Announcement of the discovery of seven rocky planets orbiting TRAPPIST-1, a star 40 light years from Earth. Three of the planets are in the habitable zone, though all seven could have liquid water. Animation with interviews featuring Sean Carey, Manager, Spitzer Science Center, Caltech/IPAC; Nikole Lewis, James Webb Telescope Project Scientist, Space Telescope Science Institute; and MIchael Gillon, Principal Investigator, TRAPPIST, University of Liege, Belgium.

A Conversation with Robert F. Christy Part I

NASA Astrophysics Data System (ADS)

Lippincott, Sara

2006-09-01

Robert F. Christy, Institute Professor of Theoretical Physics Emeritus at Caltech, recalls his childhood in British Columbia; his undergraduate years at the University of British Columbia; his graduate work with J. Robert Oppenheimer at Berkeley; and his work on the Manhattan Project, first with Enrico Fermi at the Metallurgical Laboratory of the University of Chicago and then as a member of the Theoretical Division at Los Alamos.

Team RoboSimian

NASA Image and Video Library

2015-06-09

Many members of Team RoboSimian and a few guests gather with competition hardware at a "Meet the Robots" event during the DARPA Robotics Challenge Finals in Pomona, California, on June 6, 2015. The RoboSimian team at JPL is collaborating with partners at the University of California, Santa Barbara, and the California Institute of Technology in Pasadena. Caltech manages JPL for NASA. http://photojournal.jpl.nasa.gov/catalog/PIA19329

ASK Magazine. No. 9

NASA Technical Reports Server (NTRS)

Post, Todd (Editor)

2002-01-01

Most of this issue is about ACE (Advanced Composition Explorer). We've collected stories by four members of the ACE management team: Don Margolies, the mission manager from Goddard Space Flight Center; Frandsen, science payloads manager from the Caltech Jet Propulsion Laboratory; Mary Chin, project manager in charge of spacecraft development at the Johns Hopkins Applied Physics Laboratory; and Frank Snow, operations and ground systems manager at Goddard.

Hubble tracks down a galaxy cluster's dark matter

NASA Astrophysics Data System (ADS)

2003-07-01

Unique mass map hi-res Size hi-res: 495 kb Credits: European Space Agency, NASA and Jean-Paul Kneib (Observatoire Midi-Pyrénées, France/Caltech, USA) Unique mass map This is a mass map of galaxy cluster Cl0024+1654 derived from an extensive Hubble Space Telescope campaign. The colour image is made from two images: a dark-matter map (the blue part of the image) and a 'luminous-matter' map determined from the galaxies in the cluster (the red part of the image). They were constructed by feeding Hubble and ground-based observations into advanced mathematical mass-mapping models. The map shows that dark matter is present where the galaxies clump together. The mass of the galaxies is shown in red, the mass of the dark matter in blue. The dark matter behaves like a 'glue', holding the cluster together. The dark-matter distribution in the cluster is not spherical. A secondary concentration of dark-matter mass is shown in blue to the upper right of the main concentration. Sky around galaxy cluster Cl0024+1654 hi-res Size hi-res: 3742 kb Credits: European Space Agency, NASA and Jean-Paul Kneib (Observatoire Midi-Pyrénées, France/Caltech, USA) Sky around galaxy cluster Cl0024+1654 This is a 2.5-degree field around galaxy cluster Cl0024+1654. The cluster galaxies are visible in the centre of the image in yellow. The image is a colour composite constructed from three Digitized Sky Survey 2 images: Blue (shown in blue), Red (shown in green), and Infrared (shown in red). HST observes shapes of more than 7000 faint background galaxies hi-res Size hi-res: 5593 kb Credits: European Space Agency, NASA and Jean-Paul Kneib (Observatoire Midi-Pyrénées, France/Caltech, USA) Hubble observes shapes of more than 7000 faint background galaxies Five days of observations produced the altogether 39 Hubble Wide Field and Planetary Camera 2 (WFPC2) images required to map the mass of the galaxy cluster Cl0024+1654. Each WFPC2 image has a size of about 1/150 the diameter of the full Moon. In total, the image measures 27 arc-minutes across, slightly smaller than the diameter of the Moon. The observed warped shapes of more than 7000 faint background galaxies have been converted into a unique map of the dark matter in the cluster. The images were taken through a red filter and have been reduced a factor of two in size. Ground-based image of the galaxy cluster C10024+1654 hi-res Size hi-res: 4699 kb Credits: European Space Agency, NASA and Jean-Paul Kneib (Observatoire Midi-Pyrénées, France/Caltech, USA) Ground-based image of the galaxy cluster C10024+1654 This is a colour image of the galaxy cluster C10024+1654 obtained with the CFHT12k camera at the Canada France Hawaii Telescope on Mauna Kea (Hawaii). The cluster clearly appears as a concentration of yellow galaxies in the centre of this image although cluster galaxies actually extend at least to the edge of this image. This image measures 21 x 21 arc-minutes. Clusters of galaxies are the largest stable systems in the Universe. They are like laboratories for studying the relationship between the distributions of dark and visible matter. In 1937, Fritz Zwicky realised that the visible component of a cluster (the thousands of millions of stars in each of the thousands of galaxies) represents only a tiny fraction of the total mass. About 80-85% of the matter is invisible, the so-called 'dark matter'. Although astronomers have known about the presence of dark matter for many decades, finding a technique to view its distribution is a much more recent development. Led by Drs Jean-Paul Kneib (from the Observatoire Midi-Pyrénées, France/Caltech, United States), Richard Ellis and Tommaso Treu (both Caltech, United States), the team used the NASA/ESA Hubble Space Telescope to reconstruct a unique 'mass map' of the galaxy cluster CL0024+1654. It enabled them to see for the first time on such large scales how mysterious dark matter is distributed with respect to galaxies. This comparison gives new clues on how such large clusters assemble and which role dark matter plays in cosmic evolution. Tracing dark matter is not an easy task because it does not shine. To make a map, astronomers must focus on much fainter, more distant galaxies behind the cluster. The shapes of these distant systems are distorted by the gravity of the foreground cluster. This distortion provides a measure of the cluster mass, a phenomenon known as 'weak gravitational lensing'. To map the dark matter of CL0024+1654, more than 120 hours observing time was dedicated to the team. This is the largest amount of Hubble time ever devoted to studying a galaxy cluster. Despite its distance of 4.5 thousand million light-years (about one third of the look-back time to the Big Bang) from Earth, this massive cluster is wide enough to equal the angular size of the full Moon. To make a mass map that covers the entire cluster required observations that probed 39 regions of the galaxy cluster. The investigation has resulted in the most comprehensive study of the distribution of dark matter in a galaxy cluster so far and extends more than 20 million light-years from its centre, much further than previous investigations. Many groups of researchers have tried to perform these types of measurements with ground-based telescopes. However, the technique relies heavily on finding the exact shapes of distant galaxies behind the cluster. The sharp vision of a space telescope such as NASA-ESA's Hubble is superior. The study reveals that the density of dark matter on large scales drops sharply with distance from the cluster centre. This confirms a picture that has emerged from recent detailed computer simulations. As Richard Ellis says: "Although theorists have predicted the form of dark matter in galaxy clusters from numerical simulations based on the effects of gravity alone, this is the first time we have convincing observations to back them up. Some astronomers had speculated clusters might contain large reservoirs of dark matter in their outermost regions. Assuming our cluster is representative, this is not the case." The team noticed that dark matter appears to clump together in their map. For example, they found concentrations of dark matter associated with galaxies known to be slowly falling into the system. Generally, the researchers found that the dark matter traces the cluster galaxies remarkably well and over an unprecedented range of physical scales. "When a cluster is being assembled, the dark matter will be smeared out between the galaxies where it acts like a glue," says Jean-Paul Kneib."The overall association of dark matter and 'glowing matter' is very convincing evidence that structures like CL0024+1654 grow by merging of smaller groups of galaxies that were already bound by their own dark matter components." Future investigations using Hubble's new camera, the Advanced Camera for Surveys (ACS), will extend this work when Hubble is trained on a second galaxy cluster later this year. ACS is 10 times more efficient than the Wide Field and Planetary Camera 2 used for this investigation, making it possible to study finer mass clumps in galaxy clusters and help work out how the clusters are assembled. Notes for editors The team is composed of Jean-Paul Kneib (Observatoire Midi-Pyrénées, France/Caltech, United States), Patrick Hudelot (Observatoire Midi-Pyrénées, France),Richard S. Ellis (Caltech, United States), Tommaso Treu (Caltech, United States), Graham P. Smith (Caltech, United States), Phil Marshall (MRAO, United Kingdom), Oliver Czoske (Institut für Astrophysik und Extraterrestrische Forschung, Germany), Ian Smail (University of Durham, United Kingdom) and Priya Natarajan (Yale University, United States). The ground-based observations were done with the Canada-France-Hawaii Telescope (CFHT) using the CFHT12k camera, the Keck telescopes, and the Hale 5-metre telescope at Palomar, United States, using the WIRC camera. The team will present their study at the General Assembly of the International Astronomical Union. They will also publish their results in a forthcoming issue of Astrophysical Journal. For broadcasters, animations of the discovery and general Hubble Space Telescope background footage is available from http://www.spacetelescope.org/video/releases.html Image credit: European Space Agency, NASA and Jean-Paul Kneib (Observatoire Midi-Pyrénées, France/Caltech, United States)

Glycoscience@Synchrotron: Synchrotron radiation applied to structural glycoscience

PubMed Central

de Sanctis, Daniele

2017-01-01

Synchrotron radiation is the most versatile way to explore biological materials in different states: monocrystalline, polycrystalline, solution, colloids and multiscale architectures. Steady improvements in instrumentation have made synchrotrons the most flexible intense X-ray source. The wide range of applications of synchrotron radiation is commensurate with the structural diversity and complexity of the molecules and macromolecules that form the collection of substrates investigated by glycoscience. The present review illustrates how synchrotron-based experiments have contributed to our understanding in the field of structural glycobiology. Structural characterization of protein–carbohydrate interactions of the families of most glycan-interacting proteins (including glycosyl transferases and hydrolases, lectins, antibodies and GAG-binding proteins) are presented. Examples concerned with glycolipids and colloids are also covered as well as some dealing with the structures and multiscale architectures of polysaccharides. Insights into the kinetics of catalytic events observed in the crystalline state are also presented as well as some aspects of structure determination of protein in solution. PMID:28684994

Synchrotron and Synchrotron Self-Compton Spectral Signatures and Blazar Emission Models

NASA Technical Reports Server (NTRS)

Chiang, James; Boettcher, Markus; White, Nicholas E. (Technical Monitor)

2002-01-01

We find that energy losses due to synchrotron self-Compton (BBC) emission in Blazar jets can produce distinctive signatures in the time-averaged synchrotron and SSC spectra of these objects. For a fairly broad range of particle injection distributions, SSC-loss-dominated synchrotron emission exhibits a spectral dependence Fv approximately v (exp -3/2). The presence or absence of this dependence in the optical and ultraviolet spectra of flat-spectrum radio quasars such as PC 279 and in the soft X-ray spectra of high-frequency BL Lac objects such as Mark 501 gives a robust measure of the importance of SSC losses. Furthermore, for partially cooled particle distributions, spectral breaks of varying sizes can appear in the synchrotron and SSC spectra and will be related to the spectral indices of the emission below the break. These spectral signatures place constraints on the size scale and the nonthermal particle content of the emitting plasma, as well as the observer orientation relative to the jet axis.

Observation of runaway electron beams by visible color camera in the Experimental Advanced Superconducting Tokamak

NASA Astrophysics Data System (ADS)

Shi, Yuejiang; Fu, Jia; Li, Jiahong; Yang, Yu; Wang, Fudi; Li, Yingying; Zhang, Wei; Wan, Baonian; Chen, Zhongyong

2010-03-01

The synchrotron radiation originated from the energetic runaway electrons has been measured by a visible complementary metal oxide semiconductor camera working in the wavelength ranges of 380-750 nm in the Experimental Advanced Superconducting Tokamak [H. Q. Liu et al., Plasma Phys. Contr. Fusion 49, 995 (2007)]. With a tangential viewing into the plasma in the direction of electron approach on the equatorial plane, the synchrotron radiation from the energetic runaway electrons was measured in full poloidal cross section. The synchrotron radiation diagnostics provides a direct pattern of the runaway beam inside the plasma. The energy and pitch angle of runaway electrons have been obtained according to the synchrotron radiation pattern. A stable shell shape of synchrotron radiation has been observed in a few runaway discharges.

Manufacturability of compact synchrotron mirrors

NASA Astrophysics Data System (ADS)

Douglas, Gary M.

1997-11-01

While many of the government funded research communities over the years have put their faith and money into increasingly larger synchrotrons, such as Spring8 in Japan, and the APS in the United States, a viable market appears to exist for smaller scale, research and commercial grade, compact synchrotrons. These smaller, and less expensive machines, provide the research and industrial communities with synchrotron radiation beamline access at a portion of the cost of their larger and more powerful counterparts. A compact synchrotron, such as the Aurora-2D, designed and built by Sumitomo Heavy Industries, Ltd. of japan (SHI), is a small footprint synchrotron capable of sustaining 20 beamlines. Coupled with a Microtron injector, with 150 MeV of injection energy, an entire facility fits within a 27 meter [88.5 ft] square floorplan. The system, controlled by 2 personal computers, is capable of producing 700 MeV electron energy and 300 mA stored current. Recently, an Aurora-2D synchrotron was purchased from SHI by the University of Hiroshima. The Rocketdyne Albuquerque Operations Beamline Optics Group was approached by SHI with a request to supply a group of 16 beamline mirrors for this machine. These mirrors were sufficient to supply 3 beamlines for the Hiroshima machine. This paper will address engineering issues which arose during the design and manufacturing of these mirrors.

Operation of the Australian Store.Synchrotron for macromolecular crystallography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meyer, Grischa R.; Aragão, David; Mudie, Nathan J.

2014-10-01

The Store.Synchrotron service, a fully functional, cloud computing-based solution to raw X-ray data archiving and dissemination at the Australian Synchrotron, is described. The Store.Synchrotron service, a fully functional, cloud computing-based solution to raw X-ray data archiving and dissemination at the Australian Synchrotron, is described. The service automatically receives and archives raw diffraction data, related metadata and preliminary results of automated data-processing workflows. Data are able to be shared with collaborators and opened to the public. In the nine months since its deployment in August 2013, the service has handled over 22.4 TB of raw data (∼1.7 million diffraction images). Severalmore » real examples from the Australian crystallographic community are described that illustrate the advantages of the approach, which include real-time online data access and fully redundant, secure storage. Discoveries in biological sciences increasingly require multidisciplinary approaches. With this in mind, Store.Synchrotron has been developed as a component within a greater service that can combine data from other instruments at the Australian Synchrotron, as well as instruments at the Australian neutron source ANSTO. It is therefore envisaged that this will serve as a model implementation of raw data archiving and dissemination within the structural biology research community.« less

New Dimensions for the Online Catalog: The Dartmouth College Library Experience [and] TOC/DOC at Caltech: Evolution of Citation Access Online [and] Locally Loaded Databases in Arizona State University's Online Catalog Using the CARL System.

ERIC Educational Resources Information Center

Klemperer, Katharina; And Others

1989-01-01

Each of three articles describes an academic library's online catalog that includes locally created databases. Topics covered include database and software selection; systems design and development; database producer negotiations; problems encountered during implementation; database loading; training and documentation; and future plans. (CLB)

Sensing, Navigation and Reasoning Technologies for the DARPA Urban Challenge

DTIC Science & Technology

2007-12-31

from the Applanix hardware and processed the data to account for state jumps. It then broadcast the world and local frame coordinate for the vehicle...contiguous series of control tactics, as requested by the Control. 22 Team Caltech Sensing and Mapping Subsystem Health Monitor Applanix (GPS and IMU...California Institute of Technology, Big Dog Ventures, Northrop Grumman Corporation, Mohr Davidow Ventures and Applanix Inc. The authors would also

Keypoint Density-Based Region Proposal for Fine-Grained Object Detection and Classification Using Regions with Convolutional Neural Network Features

DTIC Science & Technology

2015-12-15

Keypoint Density-based Region Proposal for Fine-Grained Object Detection and Classification using Regions with Convolutional Neural Network ... Convolutional Neural Networks (CNNs) enable them to outperform conventional techniques on standard object detection and classification tasks, their...detection accuracy and speed on the fine-grained Caltech UCSD bird dataset (Wah et al., 2011). Recently, Convolutional Neural Networks (CNNs), a deep

Content Dynamics Over the Network Cloud

DTIC Science & Technology

2015-11-04

Ferragut, “Trading Off Efficiency and Reciprocity in Wireless Peer- To-Peer File Sharing”, WiOpt 2015, Mumbai , India, May 2015. 11. A. Ferragut, F...inspired by queueing theory”, RSRG Seminar, Caltech, March 2015. q) Presentation of paper [10] by the PI at WiOpt, Mumbai , India, May 2015...2015, Mumbai , India, May 2015. 11. A. Ferragut, F. Paganini, "Queueing analysis of peer-to-peer swarms: stationary distributions and their scaling

Energetic electron anisotropies in the magnetotail - Identification of open and closed field lines

NASA Technical Reports Server (NTRS)

Baker, D. N.; Stone, E. C.

1976-01-01

Unidirectional anisotropies in the energetic electron fluxes (E greater than or equal to about 200 keV) have been observed in the earth's magnetotail with the Caltech Electron/Isotope Spectrometer on IMP-8. The anisotropies occur during periods of enhanced fluxes and provide essential information on the topology (open or closed) of the magnetotail field lines which are associated with recently identified acceleration regions.

EVLA Observations of PTF10vdl

NASA Astrophysics Data System (ADS)

Kasliwal, Mansi; Kulkarni, Shri; Arcavi, Iair; Gal-Yam, Avishay; Quimby, Robert; Ofek, Eran; Frail, Dale; Yuan, Fang; Akerlof, Carl; McKay, Time

2010-09-01

We triggered our NRAO Target Of Opportunity program "Exploring Transients in the Local Universe" and used the Expanded Very Large Array (EVLA) to observe the field of view toward PTF10vdl (ATEL#2862 an ATEL#2863), discovered by the Palomar Transient Factory . The EVLA observations were made on September 18.26 UT at a center frequency of 8.46 GHz.

CARMA Observations of PTF10vdl

NASA Astrophysics Data System (ADS)

Carpenter, John M.

2010-09-01

We used the Combined Array for Research in Millimeter-wave Astronomy (CARMA) to observe the field of view toward PTF10vdl (ATEL#2862), discovered by the Palomar Transient Factory . The observations began at September 18, 2010 04:18 UT and continued for 4.9 hours. The mean frequency of the observations was 97.5 GHz with a total bandwidth of 8 GHz.

Statistics of the MASIV 5 GHZ VLA Scintillation Survey

DTIC Science & Technology

2007-10-01

76, Epping, NSW, Australia, E-mail: david.jauncey@csiro.au James Lovell : School of Mathematics & Physics, University of Tasmania, GPO Box 252...Technology, Pasadena CA 91125, E-mail: jpm@astro.caltech.edu Hayley Bignall: Joint Institute for VLBI in Europe, Postbus 2, 7900 AA Dwingeloo, The...369, 449 [7] Lovell , J. E. J., et al., First Results from MASIV: The Microarcsecond Scintillation- induced Variability Survey, 2003, AJ, 126, 1699

Natural and accelerated recovery from brain damage: experimental and theoretical approaches.

PubMed

Andersen, Richard A; Schieber, Marc H; Thakor, Nitish; Loeb, Gerald E

2012-03-01

The goal of the Caltech group is to gain insight into the processes that occur within the primate nervous system during dexterous reaching and grasping and to see whether natural recovery from local brain damage can be accelerated by artificial means. We will create computational models of the nervous system embodying this insight and explain a variety of clinically observed neurological deficits in human subjects using these models.

Seasonal Variations in the CO Line Profile and the Retrieved Thermal/Pressure Structures in the Atmosphere of Mars

NASA Astrophysics Data System (ADS)

Khayat, Alain; Villanueva, G. L.; Mumma, M. J.; Riesen, T. E.; Tokunaga, A. T.

2013-10-01

We report retrievals of temperature vertical profiles up to 100 km over Tharsis and Syrtis regions on Mars obtained by inverting the strong rotational (3-2) line of carbon monoxide (CO) at 346 GHz. Observations of CO were made from mid Northern Spring to early Northern Summer on Mars (Ls= 36°-108°, 23 Nov, 2011 - 13 May, 2012) using the Caltech Submillimeter Observatory's (CSO) high-resolution heterodyne receiver (Barney) on top of Mauna Kea, Hawai'i. The temperature profiles were derived using our radiative transfer model that considers the latest spectroscopic constants for CO collisionally broadened by CO2. We observe notable changes of the line profile for different dates, which are directly related to seasonal variations in the thermal/pressure structure of the atmosphere. The seasonal variability of the martian CO line profile, the extracted temperature profiles, and comparisons with modeled profiles from the Mars Climate Database (Lewis et al, 1999) will be presented. We gratefully acknowledge support from the NASA Planetary Astronomy Program , NASA Astrobiology Institute, Planetary Atmospheres programs. This material is based upon work at the Caltech Submillimeter Observatory, which is operated by the California Institute of Technology under cooperative agreement with the National Science Foundation, grant number AST-0838261.

Numerical investigation of the self-starting of a vertical axis wind turbine

NASA Astrophysics Data System (ADS)

Tsai, Hsieh-Chen; Colonius, Tim

2014-11-01

The immersed boundary method is used to simulate the incompressible flow around two-dimensional airfoils at sub-scale Reynolds number in order to investigate the self-starting capability of a vertical-axis wind turbine (VAWT). By investigating a single blade fixed at various angle of attacks, the leading edge vortex (LEV) is shown to play an important role in the starting mechanism for both flat-plate and NACA 0018 blades. Depending on the angle of attack of the blade, as the LEV grows, the corresponding low pressure region results in a thrust in the tangential direction, which produces a positive torque to VAWT. Due to the characteristics of the blades, a NACA 0018 blade produces a larger thrust over a wider range of angle of attacks than a flat-plate blade. Therefore, a VAWT with NACA 0018 blades can self-start more easily than one with flat-plate blades. Moreover, by investigating the starting torque of three-bladed VAWTs fixed at various orientations, the optimal orientation that produces the largest torque to start both VAWTs is with a blade parallel to the flow and facing downstream. The simulations are also compared to results from companion water-tunnel experiments at Caltech. This project is supported by Caltech FLOWE center/Gordon and Betty Moore Foundation.

Hard X-Ray Burst Detected From Caltech Plasma Jet Experiment Magnetic Reconnection Event

NASA Astrophysics Data System (ADS)

Marshall, Ryan S.; Bellan, Paul M.

2016-10-01

In the Caltech plasma jet experiment a 100 kA MHD driven jet becomes kink unstable leading to a Rayleigh-Taylor instability that quickly causes a magnetic reconnection event. Movies show that the Rayleigh-Taylor instability is simultaneous with voltage spikes across the electrodes that provide the current that drives the jet. Hard x-rays between 4 keV and 9 keV have now been observed using an x-ray scintillator detector mounted just outside of a kapton window on the vacuum chamber. Preliminary results indicate that the timing of the x-ray burst coincides with a voltage spike on the electrodes occurring in association with the Rayleigh-Taylor event. The x-ray signal accompanies the voltage spike and Rayleigh-Taylor event in approximately 50% of the shots. A possible explanation for why the x-ray signal is sometimes missing is that the magnetic reconnection event may be localized to a specific region of the plasma outside the line of sight of the scintillator. The x-ray signal has also been seen accompanying the voltage spike when no Rayleigh-Taylor is observed. This may be due to the interframe timing on the camera being longer than the very short duration of the Rayleigh-Taylor instability.

The XXIIIrd Phage/Virus Assembly Meeting.

PubMed

Serwer, Philip

2014-01-01

The XXIIIrd Phage/Virus Assembly (PVA) meeting returned to its birthplace in Lake Arrowhead, CA on September 8-13, 2013 (Fig. 1). The original meeting occurred in 1968, organized by Bob Edgar (Caltech, Pasadena, CA USA), Fred Eiserling (University of California, Los Angeles, Los Angeles, CA USA) and Bill Wood (Caltech, Pasadena, CA USA). The organizers of the 2013 meeting were Bill Gelbart (University of California, Los Angeles, Los Angeles, CA USA) and Jack Johnson (Scripps Research Institute, La Jolla, CA USA). This meeting specializes in an egalitarian format. Students are distinguished from senior faculty primarily by the signs of age. With the exception of historically based introductory talks, all talks were allotted the same time and freedom. This tradition began when the meeting was phage-only and has been continued now that all viruses are included. Many were the animated conversations about basic questions. New and international participants were present, a sign that the field has significant attraction, as it should, based on details below. The meeting was also characterized by a sense of humor and generally good times, a chance to both enjoy the science and forget the funding malaise to which many participants are exposed. I will present some of the meeting content, without attempting to be comprehensive.

Steady X-Ray Synchrotron Emission in the Northeastern Limb of SN 1006

NASA Technical Reports Server (NTRS)

Katsuda, Satoru; Petre, Robert; Mori, Koji; Reynolds, Stephen; Long, Knox; Winkler, P.; Tsunemi, Hiroshi

2010-01-01

We investigate time variations and detailed spatial structures of X-ray synchrotron emission in the northeastern limb of SN 1006, using two Chandra observations taken in 2000 and 2008. We extract spectra from a number of small ([approx]10'') regions. After taking account of proper motion and isolating the synchrotron from the thermal emission, we study time variations in the synchrotron emission in the small regions. We find that there are no regions showing strong flux variations. Our analysis shows an apparent flux decline in the overall synchrotron flux of [approx]4% at high energies, but we suspect that this is mostly a calibration effect, and that flux is actually constant to [approx]1%. This is much less than the variation found in other remnants where it was used to infer magnetic-field strengths up to 1 mG. We attribute the lack of variability to the smoothness of the synchrotron morphology, in contrast to the small-scale knots found to be variable in other remnants. The smoothness is to be expected for a Type Ia remnant encountering uniform material. Finally, we find a spatial correlation between the flux and the cutoff frequency in synchrotron emission. The simplest interpretation is that the cutoff frequency depends on the magnetic-field strength. This would require that the maximum energy of accelerated electrons is not limited by synchrotron losses, but by some other effect. Alternatively, the rate of particle injection and acceleration may vary due to some effect not yet accounted for, such as a dependence on shock obliquity.

Synchrotron applications in wood preservation and deterioration

Treesearch

Barbara L. Illman

2003-01-01

Several non-intrusive synchrotron techniques are being used to detect and study wood decay. The techniques use high intensity synchrotron-generated X-rays to determine the atomic structure of materials with imaging, diffraction, and absorption. Some of the techniques are X-ray absorption near edge structure (XANES), X-ray fluorescence spectroscopy (XFS), X-ray...

Introducing Synchrotrons Into the Classroom

ScienceCinema

Bloch, Ashley; Lanzirotti, Tony

2018-06-08

Brookhaven's Introducing Synchrotrons Into the Classroom (InSynC) program gives teachers and their students access to the National Synchrotron Light Source through a competitive proposal process. The first batch of InSynC participants included a group of students from Islip Middle School, who used the massive machine to study the effectiveness of different what filters.

Understanding Why Researchers Should Use Synchrotron-Enhanced FTIR Instead of Traditional FTIR

ERIC Educational Resources Information Center

Stem, Michelle R.

2008-01-01

A synchrotron-enhanced Fourier transform infrared (SR-FTIR) specializes in combining the tremendous power, brightness, intensity, focusability, and tunability of the photons radiated by a synchrotron with FTIR ability to research the vibrational properties of the lighter elements (i.e., C, N, O, etc.). Infrared (IR) wavelengths correspond to the…

Industrial Use of Synchrotron Radiation:. Love at Second Sight

NASA Astrophysics Data System (ADS)

Hormes, Josef; Warner, Jeffrey

2012-06-01

Synchrotron radiation (SR) has become one of the most valuable tools for many areas of basic and applied research. In some cases, techniques have been developed that rely completely on the specific properties of synchrotron radiation; in many other cases, using synchrotron radiation has opened completely new and exciting opportunities for conventional techniques. In this chapter, the challenges, problems, and advantages of the industrial use of synchrotron radiation will be highlighted, in an admittedly subjective way, based on the experience of the authors at various synchrotron radiation facilities. "Typical" examples of industrial use of SR will be discussed for all areas of industrial activities, i.e., production, quality control and control of regulatory requirements, and research and development. Emphasis will be put on examples from R&D as this is the most intensively used area. Because this field is much too broad for a complete review here, examples will focus on applications from just three major sectors: biotechnology, pharmaceuticals and cosmetics, and automotive and mining. Environmental research is a fourth area that will be partly covered in the section on regulatory requirements.

RADIO SYNCHROTRON FLUCTUATION STATISTICS AS A PROBE OF MAGNETIZED INTERSTELLAR TURBULENCE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Herron, C. A.; Gaensler, B. M.; Burkhart, Blakesley

2016-05-01

We investigate how observations of synchrotron intensity fluctuations can be used to probe the sonic and Alfvénic Mach numbers of interstellar turbulence, based on mock observations performed on simulations of magnetohydrodynamic turbulence. We find that the structure function slope and a diagnostic of anisotropy that we call the integrated quadrupole ratio modulus both depend on the Alfvénic Mach number. However, these statistics also depend on the orientation of the mean magnetic field in the synchrotron emitting region relative to our line of sight, and this creates a degeneracy that cannot be broken by observations of synchrotron intensity alone. We concludemore » that the polarization of synchrotron emission could be analyzed to break this degeneracy, and suggest that this will be possible with the Square Kilometre Array.« less

The Scale Invariant Synchrotron Jet of Flat Spectrum Radio Quasars

NASA Astrophysics Data System (ADS)

Du, L. M.; Bai, J. M.; Xie, Z. H.; Yi, T. F.; Xu, Y. B.; Xue, R.; Wang, X. H.

2015-06-01

In this paper, the scale invariance of the synchrotron jet of Flat Spectrum Radio Quasars has been studied using a sample of combined sources from FKM04 and from SDSS DR3 catalogue. Since the research of scale invariance has been focused on sub-Eddington cases that can be fitted onto the fundamental plane, while near-Eddington sources such as FSRQs have not been explicitly studied. The extracted physical properties of synchrotron jet of FSRQs have been shown to be scale invariant using our sample. The results are in good agreement with theoretical expectations of Heinz & Sunyaev (2003). Therefore, the jet synchrotron is shown to be scale independent, regardless of the accretion modes. Results in this article thus lend support to the scale invariant model of the jet synchrotron throughout the mass scale of black hole systems.

Ultra-spatial synchrotron radiation for imaging molecular chemical structure: Applications in plant and animal studies

DOE PAGES

Yu, Peiqiang

2007-01-01

Synchrotron-based Fourier transform infrared microspectroscopy (S-FTIR) has been developed as a rapid, direct, non-destructive, bioanalytical technique. This technique takes advantage of synchrotron light brightness and small effective source size and is capable of exploring the molecular chemical features and make-up within microstructures of a biological tissue without destruction of inherent structures at ultra-spatial resolutions within cellular dimension. To date there has been very little application of this advanced synchrotron technique to the study of plant and animal tissues' inherent structure at a cellular or subcellular level. In this article, a novel approach was introduced to show the potential of themore » newly developed, advanced synchrotron-based analytical technology, which can be used to reveal molecular structural-chemical features of various plant and animal tissues.« less

Applications of synchrotron-based spectroscopic techniques in studying nucleic acids and nucleic acid-functionalized nanomaterials

PubMed Central

Wu, Peiwen; Yu, Yang; McGhee, Claire E.; Tan, Li Huey

2014-01-01

In this review, we summarize recent progresses in the application of synchrotron-based spectroscopic techniques for nucleic acid research that takes advantage of high-flux and high-brilliance electromagnetic radiation from synchrotron sources. The first section of the review focuses on the characterization of the structure and folding processes of nucleic acids using different types of synchrotron-based spectroscopies, such as X-ray absorption spectroscopy, X-ray emission spectroscopy, X-ray photoelectron spectroscopy, synchrotron radiation circular dichroism, X-ray footprinting and small-angle X-ray scattering. In the second section, the characterization of nucleic acid-based nanostructures, nucleic acid-functionalized nanomaterials and nucleic acid-lipid interactions using these spectroscopic techniques is summarized. Insights gained from these studies are described and future directions of this field are also discussed. PMID:25205057

Applications of synchrotron-based spectroscopic techniques in studying nucleic acids and nucleic acid-functionalized nanomaterials

DOE PAGES

Wu, Peiwen; Yu, Yang; McGhee, Claire E.; ...

2014-09-10

In this paper, we summarize recent progress in the application of synchrotron-based spectroscopic techniques for nucleic acid research that takes advantage of high-flux and high-brilliance electromagnetic radiation from synchrotron sources. The first section of the review focuses on the characterization of the structure and folding processes of nucleic acids using different types of synchrotron-based spectroscopies, such as X-ray absorption spectroscopy, X-ray emission spectroscopy, X-ray photoelectron spectroscopy, synchrotron radiation circular dichroism, X-ray footprinting and small-angle X-ray scattering. In the second section, the characterization of nucleic acid-based nanostructures, nucleic acid-functionalized nanomaterials and nucleic acid-lipid interactions using these spectroscopic techniques is summarized. Insightsmore » gained from these studies are described and future directions of this field are also discussed.« less

3 GeV Booster Synchrotron Conceptual Design Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wiedemann, Helmut

2009-06-02

Synchrotron light cna be produced from a relativistic particle beam circulating in a storage ring at extremely high intensity and brilliance over a large spectral region reaching from the far infrared regime to hard x-rays. The particles, either electrons or positrons, radiate as they are deflected in the fields of the storage ring bending magnets or of magnets specially optimized for the production of synchrotron light. The synchrotron light being very intense and well collimated in the forward direction has become a major tool in a large variety of research fields in physics, chemistry, material science, biology, and medicine.

Synchrotron Intensity Gradients as Tracers of Interstellar Magnetic Fields

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lazarian, A.; Yuen, Ka Ho; Lee, Hyeseung

On the basis of the modern understanding of MHD turbulence, we propose a new way of using synchrotron radiation: using synchrotron intensity gradients (SIGs) for tracing astrophysical magnetic fields. We successfully test the new technique using synthetic data obtained with 3D MHD simulations and provide the demonstration of the practical utility of the technique by comparing the directions of magnetic fields that are obtained with PLANCK synchrotron intensity data to the directions obtained with PLANCK synchrotron polarization data. We demonstrate that the SIGs can reliably trace magnetic fields in the presence of noise and can provide detailed maps of magneticmore » field directions. We also show that the SIGs are relatively robust for tracing magnetic fields while the low spatial frequencies of the synchrotron image are removed. This makes the SIGs applicable to the tracing of magnetic fields using interferometric data with single-dish measurement absent. We discuss the synergy of using the SIGs together with synchrotron polarization in order to find the actual direction of the magnetic fields and quantify the effects of Faraday rotation as well as with other ways of studying astrophysical magnetic fields. We test our method in the presence of noise and the resolution effects. We stress the complementary nature of the studies using the SIG technique and those employing the recently introduced velocity gradient techniques that trace magnetic fields using spectroscopic data.« less

Synchrotron Intensity Gradients as Tracers of Interstellar Magnetic Fields

NASA Astrophysics Data System (ADS)

Lazarian, A.; Yuen, Ka Ho; Lee, Hyeseung; Cho, J.

2017-06-01

On the basis of the modern understanding of MHD turbulence, we propose a new way of using synchrotron radiation: using synchrotron intensity gradients (SIGs) for tracing astrophysical magnetic fields. We successfully test the new technique using synthetic data obtained with 3D MHD simulations and provide the demonstration of the practical utility of the technique by comparing the directions of magnetic fields that are obtained with PLANCK synchrotron intensity data to the directions obtained with PLANCK synchrotron polarization data. We demonstrate that the SIGs can reliably trace magnetic fields in the presence of noise and can provide detailed maps of magnetic field directions. We also show that the SIGs are relatively robust for tracing magnetic fields while the low spatial frequencies of the synchrotron image are removed. This makes the SIGs applicable to the tracing of magnetic fields using interferometric data with single-dish measurement absent. We discuss the synergy of using the SIGs together with synchrotron polarization in order to find the actual direction of the magnetic fields and quantify the effects of Faraday rotation as well as with other ways of studying astrophysical magnetic fields. We test our method in the presence of noise and the resolution effects. We stress the complementary nature of the studies using the SIG technique and those employing the recently introduced velocity gradient techniques that trace magnetic fields using spectroscopic data.

PREFACE: International Conference on Computing in High Energy and Nuclear Physics (CHEP 2010)

NASA Astrophysics Data System (ADS)

Lin, Simon C.; Shen, Stella; Neufeld, Niko; Gutsche, Oliver; Cattaneo, Marco; Fisk, Ian; Panzer-Steindel, Bernd; Di Meglio, Alberto; Lokajicek, Milos

2011-12-01

The International Conference on Computing in High Energy and Nuclear Physics (CHEP) was held at Academia Sinica in Taipei from 18-22 October 2010. CHEP is a major series of international conferences for physicists and computing professionals from the worldwide High Energy and Nuclear Physics community, Computer Science, and Information Technology. The CHEP conference provides an international forum to exchange information on computing progress and needs for the community, and to review recent, ongoing and future activities. CHEP conferences are held at roughly 18 month intervals, alternating between Europe, Asia, America and other parts of the world. Recent CHEP conferences have been held in Prauge, Czech Republic (2009); Victoria, Canada (2007); Mumbai, India (2006); Interlaken, Switzerland (2004); San Diego, California(2003); Beijing, China (2001); Padova, Italy (2000) CHEP 2010 was organized by Academia Sinica Grid Computing Centre. There was an International Advisory Committee (IAC) setting the overall themes of the conference, a Programme Committee (PC) responsible for the content, as well as Conference Secretariat responsible for the conference infrastructure. There were over 500 attendees with a program that included plenary sessions of invited speakers, a number of parallel sessions comprising around 260 oral and 200 poster presentations, and industrial exhibitions. We thank all the presenters, for the excellent scientific content of their contributions to the conference. Conference tracks covered topics on Online Computing, Event Processing, Software Engineering, Data Stores, and Databases, Distributed Processing and Analysis, Computing Fabrics and Networking Technologies, Grid and Cloud Middleware, and Collaborative Tools. The conference included excursions to various attractions in Northern Taiwan, including Sanhsia Tsu Shih Temple, Yingko, Chiufen Village, the Northeast Coast National Scenic Area, Keelung, Yehliu Geopark, and Wulai Aboriginal Village, as well as two banquets held at the Grand Hotel and Grand Formosa Regent in Taipei. The next CHEP conference will be held in New York, the United States on 21-25 May 2012. We would like to thank the National Science Council of Taiwan, the EU ACEOLE project, commercial sponsors, and the International Advisory Committee and the Programme Committee members for all their support and help. Special thanks to the Programme Committee members for their careful choice of conference contributions and enormous effort in reviewing and editing about 340 post conference proceedings papers. Simon C Lin CHEP 2010 Conference Chair and Proceedings Editor Taipei, Taiwan November 2011 Track Editors/ Programme Committee Chair Simon C Lin, Academia Sinica, Taiwan Online Computing Track Y H Chang, National Central University, Taiwan Harry Cheung, Fermilab, USA Niko Neufeld, CERN, Switzerland Event Processing Track Fabio Cossutti, INFN Trieste, Italy Oliver Gutsche, Fermilab, USA Ryosuke Itoh, KEK, Japan Software Engineering, Data Stores, and Databases Track Marco Cattaneo, CERN, Switzerland Gang Chen, Chinese Academy of Sciences, China Stefan Roiser, CERN, Switzerland Distributed Processing and Analysis Track Kai-Feng Chen, National Taiwan University, Taiwan Ulrik Egede, Imperial College London, UK Ian Fisk, Fermilab, USA Fons Rademakers, CERN, Switzerland Torre Wenaus, BNL, USA Computing Fabrics and Networking Technologies Track Harvey Newman, Caltech, USA Bernd Panzer-Steindel, CERN, Switzerland Antonio Wong, BNL, USA Ian Fisk, Fermilab, USA Niko Neufeld, CERN, Switzerland Grid and Cloud Middleware Track Alberto Di Meglio, CERN, Switzerland Markus Schulz, CERN, Switzerland Collaborative Tools Track Joao Correia Fernandes, CERN, Switzerland Philippe Galvez, Caltech, USA Milos Lokajicek, FZU Prague, Czech Republic International Advisory Committee Chair: Simon C. Lin , Academia Sinica, Taiwan Members: Mohammad Al-Turany , FAIR, Germany Sunanda Banerjee, Fermilab, USA Dario Barberis, CERN & Genoa University/INFN, Switzerland Lothar Bauerdick, Fermilab, USA Ian Bird, CERN, Switzerland Amber Boehnlein, US Department of Energy, USA Kors Bos, CERN, Switzerland Federico Carminati, CERN, Switzerland Philippe Charpentier, CERN, Switzerland Gang Chen, Institute of High Energy Physics, China Peter Clarke, University of Edinburgh, UK Michael Ernst, Brookhaven National Laboratory, USA David Foster, CERN, Switzerland Merino Gonzalo, CIEMAT, Spain John Gordon, STFC-RAL, UK Volker Guelzow, Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany John Harvey, CERN, Switzerland Frederic Hemmer, CERN, Switzerland Hafeez Hoorani, NCP, Pakistan Viatcheslav Ilyin, Moscow State University, Russia Matthias Kasemann, DESY, Germany Nobuhiko Katayama, KEK, Japan Milos Lokajícek, FZU Prague, Czech Republic David Malon, ANL, USA Pere Mato Vila, CERN, Switzerland Mirco Mazzucato, INFN CNAF, Italy Richard Mount, SLAC, USA Harvey Newman, Caltech, USA Mitsuaki Nozaki, KEK, Japan Farid Ould-Saada, University of Oslo, Norway Ruth Pordes, Fermilab, USA Hiroshi Sakamoto, The University of Tokyo, Japan Alberto Santoro, UERJ, Brazil Jim Shank, Boston University, USA Alan Silverman, CERN, Switzerland Randy Sobie , University of Victoria, Canada Dongchul Son, Kyungpook National University, South Korea Reda Tafirout , TRIUMF, Canada Victoria White, Fermilab, USA Guy Wormser, LAL, France Frank Wuerthwein, UCSD, USA Charles Young, SLAC, USA

From the Blazar Sequence to the Blazar Envelope: Revisiting the Relativistic Jet Dichotomy in Radio-Loud AGN

NASA Technical Reports Server (NTRS)

Meyer, Eileen T.; Fossati, Giovanini; Georganopoulos, Markos; Lister, Matthew L.

2012-01-01

We revisit the concept of a blazar sequence that relates the synchrotron peak frequency (Vpeak) in blazars with synchrotron peak luminosity (Lpeak, in vLv) using a large sample of radio-loud AGN. We present observational evidence that the blazar sequence is formed from two populations in the synchrotron Vpeak - Lpeak plane, each forming an upper edge to an envelope of progressively misaligned blazars, and connecting to an adjacent group of radio galaxies having jets viewed at much larger angles to the line of sight. When binned by jet kinetic power (Lkin; as measured through a scaling relationship with extended radio power), we find that radio core dominance decreases with decreasing synchrotron Lpeak, revealing that sources in the envelope are generally more misaligned. We find population-based evidence of velocity gradients in jets at low kinetic powers (approximately 10(exp 42) - 10(exp 44.5) erg s(exp -1)), corresponding to FR I radio galaxies and most BL Lacs. These low jet power 'weak jet' sources, thought to exhibit radiatively inefficient accretion, are distinguished from the population of non-decelerating, low synchrotron-peaking (LSP) blazars and FR II radio galaxies ('strong' jets) which are thought to exhibit radiatively efficient accretion. The two-population interpretation explains the apparent contradiction of the existence of highly core-dominated, low-power blazars at both low and high synchrotron peak frequencies, and further implies that most intermediate synchrotron peak (ISP) sources are not intermediate in intrinsic jet power between LSP and high synchrotron-peaking (HSP) sources, but are more misaligned versions of HSP sources with similar jet powers.

Compton scattering of self-absorbed synchrotron emission

NASA Astrophysics Data System (ADS)

Gao, He; Lei, Wei-Hua; Wu, Xue-Feng; Zhang, Bing

2013-11-01

Synchrotron self-Compton (SSC) scattering is an important emission mechanism in many astronomical sources, such as gamma-ray bursts (GRBs) and active galactic nuclei. We give a complete presentation of the analytical approximations for the Compton scattering of synchrotron emission with both weak and strong synchrotron self-absorption. All possible orders of the characteristic synchrotron spectral breaks (νa, νm and νc) are studied. In the weak self-absorption regime, i.e. νa < νc, the electron energy distribution is not modified by the self-absorption process. The shape of the SSC component broadly resembles that of synchrotron, but with the following features: The SSC flux increases linearly with frequency up to the SSC break frequency corresponding to the self-absorption frequency νa; and the presence of a logarithmic term in the high-frequency range of the SSC spectra makes it harder than the power-law approximation. In the strong absorption regime, i.e. νa > νc, heating of low-energy electrons due to synchrotron absorption leads to pile-up of electrons, and form a thermal component besides the broken power-law component. This leads to two-component (thermal + non-thermal) spectra for both the synchrotron and SSC spectral components. For νc < νa < νm, the spectrum is thermal (non-thermal) dominated if ν _a > √{ν _m ν _c} (ν _a < √{ν _m ν _c}). Similar to the weak-absorption regime, the SSC spectral component is broader than the simple broken power-law approximation. We derive the critical condition for strong absorption (electron pile-up), and discuss a case of GRB reverse shock emission in a wind medium, which invokes νa > max(νm, νc).

Relativistic turbulence with strong synchrotron and synchrotron self-Compton cooling

NASA Astrophysics Data System (ADS)

Uzdensky, D. A.

2018-07-01

Many relativistic plasma environments in high-energy astrophysics, including pulsar wind nebulae (PWN), hot accretion flows on to black holes, relativistic jets in active galactic nuclei and gamma-ray bursts, and giant radio lobes, are naturally turbulent. The plasma in these environments is often so hot that synchrotron and inverse-Compton (IC) radiative cooling becomes important. In this paper, we investigate the general thermodynamic and radiative properties (and hence the observational appearance) of an optically thin relativistically hot plasma stirred by driven magnetohydrodynamic (MHD) turbulence and cooled by radiation. We find that if the system reaches a statistical equilibrium where turbulent heating is balanced by radiative cooling, the effective electron temperature tends to attain a universal value θ = kT_e/m_e c^2 ˜ 1/√{τ _T}, where τT = neσTL ≪ 1 is the system's Thomson optical depth, essentially independent of the strength of turbulent driving and hence of the magnetic field. This is because both MHD turbulent dissipation and synchrotron cooling are proportional to the magnetic energy density. We also find that synchrotron self-Compton (SSC) cooling and perhaps a few higher order IC components are automatically comparable to synchrotron in this regime. The overall broad-band radiation spectrum then consists of several distinct components (synchrotron, SSC, etc.), well separated in photon energy (by a factor ˜ τ_T^{-1}) and roughly equal in power. The number of IC peaks is checked by Klein-Nishina effects and depends logarithmically on τT and the magnetic field. We also examine the limitations due to synchrotron self-absorption, explore applications to Crab PWN and blazar jets, and discuss links to radiative magnetic reconnection.

Synchrotron light sources in developing countries

DOE PAGES

Mtingwa, Sekazi K.; Winick, Herman

2018-03-21

Here, we discuss the role that synchrotron light sources, such as SESAME, could play in improving the socioeconomic conditions in developing countries. After providing a brief description of a synchrotron light source, we discuss the important role that they played in the development of several economically emerging countries. Then we describe the state of synchrotron science in South Africa and that country’s leadership role in founding the African Light Source initiative. Next, we highlight a new initiative called Lightsources for Africa, the Americas & Middle East Project, which is a global initiative led by the International Union of Pure andmore » Applied Physics and the International Union of Crystallography, with initial funding provided by the International Council for Science. Finally, we comment on a new technology called the multibend achromat that has launched a new paradigm for the design of synchrotron light sources that should be attractive for construction in developing countries.« less

Synchrotron light sources in developing countries

NASA Astrophysics Data System (ADS)

Mtingwa, Sekazi K.; Winick, Herman

2018-03-01

We discuss the role that synchrotron light sources, such as SESAME, could play in improving the socioeconomic conditions in developing countries. After providing a brief description of a synchrotron light source, we discuss the important role that they played in the development of several economically emerging countries. Then we describe the state of synchrotron science in South Africa and that country’s leadership role in founding the African Light Source initiative. Next, we highlight a new initiative called Lightsources for Africa, the Americas & Middle East Project, which is a global initiative led by the International Union of Pure and Applied Physics and the International Union of Crystallography, with initial funding provided by the International Council for Science. Finally, we comment on a new technology called the multibend achromat that has launched a new paradigm for the design of synchrotron light sources that should be attractive for construction in developing countries.

Recent research in flaxseed (oil seed) on molecular structure and metabolic characteristics of protein, heat processing-induced effect and nutrition with advanced synchrotron-based molecular techniques.

PubMed

Doiron, Kevin J; Yu, Peiqiang

2017-01-02

Advanced synchrotron radiation-based infrared microspectroscopy is able to reveal feed and food structure feature at cellular and molecular levels and simultaneously provides composition, structure, environment, and chemistry within intact tissue. However, to date, this advanced synchrotron-based technique is still seldom known to food and feed scientists. This article aims to provide detailed background for flaxseed (oil seed) protein research and then review recent progress and development in flaxseed research in ruminant nutrition in the areas of (1) dietary inclusion of flaxseed in rations; (2) heat processing effect; (3) assessing dietary protein; (4) synchrotron-based Fourier transform infrared microspectroscopy as a tool of nutritive evaluation within cellular and subcellular dimensions; (5) recent synchrotron applications in flaxseed research on a molecular basis. The information described in this paper gives better insight in flaxseed research progress and update.

Some aspects of cosmic synchrotron sources

NASA Technical Reports Server (NTRS)

Epstein, R. I.

1973-01-01

Synchrotron emission is considered from individual particles which have small pitch angles and the general properties of synchrotron sources which mainly contain such particles, as well as the emissivities and degrees of circular polarization for specific source distributions. The limitation of synchrotron source models for optical pulsars and compact extragalactic objects are discussed, and it is shown that several existing models for the pulsar NP 0532 are inconsistent with the measured time variations and polarizations of the optical emission. Discussion is made also of whether the low frequency falloffs in the extragalactic objects PKS 2134 + 004, OQ 208, and NGC 1068 is due to emission from particles with small pitch angles or absorption by a thermal plasma or synchrotron self-absorption. It is concluded that the absorption interpretations cannot account for the turnover in the spectrum of PKS 2134 + 004. Measurements of polarization, angular structure, and X-ray flux are also described.

Atomic physics research with second and third generation synchrotron light sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, B.M.

1990-10-01

This contribution to these proceedings is intended to provide an introduction and overview for other contributions on atomic (and related) physics research at existing and planned synchrotron light sources. The emphasis will be on research accomplishments and future opportunities, but a comparison will be given of operating characteristics for first, second, and third generation machines. First generation light sources were built to do research with the primary electron and positron beams, rather than with the synchrotron radiation itself. Second generation machines were specifically designed to be dedicated synchrotron-radiation facilities, with an emphasis on the use of bending-magnet radiation. The newmore » third generation light sources are being designed to optimize radiation from insertion devices, such as undulators and wigglers. Each generation of synchrotron light source offers useful capabilities for forefront research in atomic physics and many other disciplines. 27 refs., 1 fig., 3 tabs.« less

Synchrotron light sources in developing countries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mtingwa, Sekazi K.; Winick, Herman

Here, we discuss the role that synchrotron light sources, such as SESAME, could play in improving the socioeconomic conditions in developing countries. After providing a brief description of a synchrotron light source, we discuss the important role that they played in the development of several economically emerging countries. Then we describe the state of synchrotron science in South Africa and that country’s leadership role in founding the African Light Source initiative. Next, we highlight a new initiative called Lightsources for Africa, the Americas & Middle East Project, which is a global initiative led by the International Union of Pure andmore » Applied Physics and the International Union of Crystallography, with initial funding provided by the International Council for Science. Finally, we comment on a new technology called the multibend achromat that has launched a new paradigm for the design of synchrotron light sources that should be attractive for construction in developing countries.« less

Studies of beam injection with a compensated bump and uncompensated bump in a synchrotron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Akbar Fakhri, Ali; Prajapati, S. K.; Ghodke, A. D.

2013-08-15

Synchrotron radiation sources Indus-1 and Indus-2 have a synchrotron as the common injector. A three kicker compensated bump injection scheme was employed for beam injection into this synchrotron. The stored beam current in the synchrotron is higher, when all the three kickers are operated at the same current than when kickers are operated at currents required to generate compensated bump. Beam dynamics studies have been done to understand why this happens. Theoretical studies indicate that higher stored current in the later case is attributed to smaller residual oscillations of injected beam. These studies also reveal that if the angle ofmore » the injected beam during beam injection is kept varying, the performance could be further improved. This is experimentally confirmed by injecting the beam on rising part of the injection septum magnet current pulse.« less

Cosmic rays, gamma rays and synchrotron radiation from the Galaxy

DOE PAGES

Orlando, Elena

2012-07-30

Galactic cosmic rays (CR), interstellar gamma-ray emission and synchrotron radiation are related topics. CR electrons propagate in the Galaxy and interact with the interstellar medium, producing inverse-Compton emission measured in gamma rays and synchrotron emission measured in radio. I present an overview of the latest results with Fermi/LAT on the gamma-ray diffuse emission induced by CR nuclei and electrons. Then I focus on the recent complementary studies of the synchrotron emission in the light of the latest gamma-ray results. Relevant observables include spectral indices and their variations, using surveys over a wide range of radio frequencies. As a result, thismore » paper emphasizes the importance of using the parallel study of gamma rays and synchrotron radiation in order to constrain the low-energy interstellar CR electron spectrum, models of propagation of CRs, and magnetic fields.« less

DIVA (Data Intensive Architecture)

DTIC Science & Technology

2004-06-01

Itanium-based workstation as a test bench for the larger system concepts. 44 10. Publications [Hall99] M. Hall, P. Kogge, J. Koller, P. Diniz ...White, Dr. Pedro Diniz . Mr. Pablo Moissett • Caltech: Dr. Thomas Sterling, Mr. Daniel Savarese • University of Notre Dame: Dr. Peter Kogge, Dr. Jay...IEEE Computer, April 1995, pp. 23-31. [Hall99] M. Hall, P. Kogge, J. Koller, P. Diniz , J. Chame, J. Draper, J. LaCoss, J. Granacki, J. Brockman

Improved Ambient Pressure Pyroelectric Ion Source

NASA Technical Reports Server (NTRS)

Beegle, Luther W.; Kim, Hugh I.; Kanik, Isik; Ryu, Ernest K.; Beckett, Brett

2011-01-01

The detection of volatile vapors of unknown species in a complex field environment is required in many different applications. Mass spectroscopic techniques require subsystems including an ionization unit and sample transport mechanism. All of these subsystems must have low mass, small volume, low power, and be rugged. A volatile molecular detector, an ambient pressure pyroelectric ion source (APPIS) that met these requirements, was recently reported by Caltech researchers to be used in in situ environments.

Enhanced Hydrogen Dipole Physisorption, Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahn, Channing

2014-01-03

The hydrogen gas adsorption effort at Caltech was designed to probe and apply our understanding of known interactions between molecular hydrogen and adsorbent surfaces as part of a materials development effort to enable room temperature storage of hydrogen at nominal pressure. The work we have performed over the past five years has been tailored to address the outstanding issues associated with weak hydrogen sorbent interactions in order to find an adequate solution for storage tank technology.

Caltech/JPL Conference on Image Processing Technology, Data Sources and Software for Commercial and Scientific Applications

NASA Technical Reports Server (NTRS)

Redmann, G. H.

1976-01-01

Recent advances in image processing and new applications are presented to the user community to stimulate the development and transfer of this technology to industrial and commercial applications. The Proceedings contains 37 papers and abstracts, including many illustrations (some in color) and provides a single reference source for the user community regarding the ordering and obtaining of NASA-developed image-processing software and science data.

The Tunnels of Samos

NASA Technical Reports Server (NTRS)

Apostol, Tom M. (Editor)

1995-01-01

This 'Project Mathematics' series video from CalTech presents the tunnel of Samos, a famous underground aquaduct tunnel located near the capital of Pithagorion (named after the famed Greek mathematician, Pythagoras, who lived there), on one of the Greek islands. This tunnel was constructed around 600 BC by King Samos and was built under a nearby mountain. Through film footage and computer animation, the mathematical principles and concepts of why and how this aquaduct tunnel was built are explained.

Studying the Sky/Planets Can Drown You in Images: Machine Learning Solutions at JPL/Caltech

NASA Technical Reports Server (NTRS)

Fayyad, U. M.

1995-01-01

JPL is working to develop a domain-independent system capable of small-scale object recognition in large image databases for science analysis. Two applications discussed are the cataloging of three billion sky objects in the Sky Image Cataloging and Analysis Tool (SKICAT) and the detection of possibly one million small volcanoes visible in the Magellan synthetic aperture radar images of Venus (JPL Adaptive Recognition Tool, JARTool).

Shielding calculations for the National Synchrotron Light Source-II experimental beamlines

NASA Astrophysics Data System (ADS)

Job, Panakkal K.; Casey, William R.

2013-01-01

Brookhaven National Laboratory is in the process of building a new Electron storage ring for scientific research using synchrotron radiation. This facility, called the "National Synchrotron Light Source II" (NSLS-II), will provide x-ray radiation of ultra-high brightness and exceptional spatial and energy resolution. It will also provide advanced insertion devices, optics, detectors, and robotics, designed to maximize the scientific output of the facility. The project scope includes the design of an electron storage ring and the experimental beamlines, which stores a maximum of 500 mA electron beam current at an energy of 3.0 GeV. When fully built there will be at least 58 beamlines using synchrotron radiation for experimental programs. It is planned to operate the facility primarily in a top-off mode, thereby maintaining the maximum variation in the synchrotron radiation flux to <1%. Because of the very demanding requirements for synchrotron radiation brilliance for the experiments, each of the 58 beamlines will be unique in terms of the source properties and experimental configuration. This makes the shielding configuration of each of the beamlines unique. The shielding calculation methodology and the results for five representative beamlines of NSLS-II, have been presented in this paper.

3D-analysis of plant microstructures: advantages and limitations of synchrotron X-ray microtomography

NASA Astrophysics Data System (ADS)

Matsushima, U.; Graf, W.; Zabler, S.; Manke, I.; Dawson, M.; Choinka, G.; Hilger, A.; Herppich, W. B.

2013-01-01

Synchrotron X-ray computer microtomography was used to analyze the microstructure of rose peduncles. Samples from three rose cultivars, differing in anatomy, were scanned to study the relation between tissue structure and peduncles mechanical strength. Additionally, chlorophyll fluorescence imaging and conventional light microscopy was applied to quantify possible irradiation-induced damage to plant physiology and tissue structure. The spatial resolution of synchrotron X-ray computer microtomography was sufficiently high to investigate the complex tissues of intact rose peduncles without the necessity of any preparation. However, synchrotron X-radiation induces two different types of damage on irradiated tissues. First, within a few hours after first X-ray exposure, there is a direct physical destruction of cell walls. In addition, a slow and delayed destruction of chlorophyll and, consequently, of photosynthetic activity occurred within hours/ days after the exposure. The results indicate that synchrotron X-ray computer microtomography is well suited for three-dimensional visualization of the microstructure of rose peduncles. However, in its current technique, synchrotron X-ray computer microtomography is not really non-destructive but induce tissue damage. Hence, this technique needs further optimization before it can be applied for time-series investigations of living plant materials

Relativistic MHD Turbulence with Synchrotron and Inverse-Compton Radiation Cooling

NASA Astrophysics Data System (ADS)

Uzdensky, Dmitri

2017-10-01

This work investigates the energetic aspects and observational appearance of driven relativistic MHD turbulence in an optically thin, relativistically hot plasma subject to strong synchrotron and synchrotron-self-Compton (SSC) radiative cooling. Steady-state balance between turbulent heating and radiative cooling is shown to lead, essentially independent of turbulent driving's strength, to a characteristic electron temperature of Te /mec2 τT- 1 / 2 , where τT << 1 is the system's Thomson optical depth. Furthermore, the SSC cooling power becomes automatically comparable to the synchrotron power. Under certain conditions, a few higher-order inverse-Compton components also become comparable to the synchrotron and SSC losses, and so the broad-band radiation spectrum of the system consists of several distinct peaks with gradually decreasing luminosity, separated by a factor of τT- 1 >> 1 from each other. The number of these spectral components is governed by synchrotron self-absorption and Klein-Nishina effects. These findings have important implications for several classes of high-energy astrophysical systems including pulsar wind nebulae and black-hole-driven accretion flows, jets, and radio-lobes. Work supported by NSF, DOE, NASA, IAS, and the Ambrose Monell Foundation.

VizieR Online Data Catalog: Spitzer Atlas of Stellar Spectra (SASS) (Ardila+, 2010)

NASA Astrophysics Data System (ADS)

Ardila, D. R.; van Dyk, S. D.; Makowiecki, W.; Stauffer, J.; Song, I.; Rho, J.; Fajardo-Acosta, S.; Hoard, D. W.; Wachter, S.

2010-11-01

From IRS Staring observations in the Spitzer archive we selected those stellar targets that had been observed with all the low-resolution IRS modules. We did not include known young stars with circumstellar material, stars known to harbor debris disks, or objects classified in SIMBAD as RS CVn, Be stars, or eclipsing binaries. We have also avoided classes already fully described with IRAS, ISO, or Spitzer, such as Asymptotic Giant Branch stars and rejected targets presenting IR excesses. However, note that in the case of very massive and/or evolved stars there are few objects presenting a pure photospheric spectrum. A few stars are specifically selected for their intrinsic interest regardless of their IR excess and even if the Atlas already contained another star with the same spectral type. The spectral coverage only reaches to 14um in the case of very late spectral classes (late M, L and T dwarfs) and some WR stars for which the long wavelength modules are unusable or not present in the archive. The spectral types have been taken from (in order of priority): * NStED (http://nsted.ipac.caltech.edu/), * NStars (http://nstars.nau.edu/nau_nstars/about.htm), * the Tycho-2 Spectral Type Catalog (Cat. III/231) * SIMBAD. For certain types of objects, we have used specialized catalogs as the source of the spectral types. The data were processed with the Spitzer Science Center S18.7.0 pipelined and corrected for teardrop effects, slit position uncertainties, residual flat-field errors, residual model errors, 24um flux deficit (1), fringing, and order mismatches. The Atlas files contain an error value for each wavelength, intended to represent the random 1sig error at that wavelength. This is the error provided by the SSC's S18.7.0 pipeline and propagated along the reduction procedure. The treatment of errors remains incomplete in this pipeline (2). The errors provided here should be considered carefully, before propagating them into further calculations. However, the processing insures that the spectra do not have strong spurious emission or absorption lines in large signal-to-noise regions. (1) http://ssc.spitzer.caltech.edu/irs/irsinstrumenthandbook/102/ #Toc253561116 (2) http://ssc.spitzer.caltech.edu/irs/irsinstrumenthandbook/ (4 data files).

Battery-Powered RF Pre-Ionization System for the Caltech Magnetohydrodynamically-Driven Jet Experiment: RF Discharge Properties and MHD-Driven Jet Dynamics

NASA Astrophysics Data System (ADS)

Chaplin, Vernon H.

This thesis describes investigations of two classes of laboratory plasmas with rather different properties: partially ionized low pressure radiofrequency (RF) discharges, and fully ionized high density magnetohydrodynamically (MHD)-driven jets. An RF pre-ionization system was developed to enable neutral gas breakdown at lower pressures and create hotter, faster jets in the Caltech MHD-Driven Jet Experiment. The RF plasma source used a custom pulsed 3 kW 13.56 MHz RF power amplifier that was powered by AA batteries, allowing it to safely float at 4-6 kV with the cathode of the jet experiment. The argon RF discharge equilibrium and transport properties were analyzed, and novel jet dynamics were observed. Although the RF plasma source was conceived as a wave-heated helicon source, scaling measurements and numerical modeling showed that inductive coupling was the dominant energy input mechanism. A one-dimensional time-dependent fluid model was developed to quantitatively explain the expansion of the pre-ionized plasma into the jet experiment chamber. The plasma transitioned from an ionizing phase with depressed neutral emission to a recombining phase with enhanced emission during the course of the experiment, causing fast camera images to be a poor indicator of the density distribution. Under certain conditions, the total visible and infrared brightness and the downstream ion density both increased after the RF power was turned off. The time-dependent emission patterns were used for an indirect measurement of the neutral gas pressure. The low-mass jets formed with the aid of the pre-ionization system were extremely narrow and collimated near the electrodes, with peak density exceeding that of jets created without pre-ionization. The initial neutral gas distribution prior to plasma breakdown was found to be critical in determining the ultimate jet structure. The visible radius of the dense central jet column was several times narrower than the axial current channel radius, suggesting that the outer portion of the jet must have been force free, with the current parallel to the magnetic field. The studies of non-equilibrium flows and plasma self-organization being carried out at Caltech are relevant to astrophysical jets and fusion energy research.

Machine detector interface studies: Layout and synchrotron radiation estimate in the future circular collider interaction region

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boscolo, Manuela; Burkhardt, Helmut; Sullivan, Michael

The interaction region layout for the e +e – future circular collider FCC-ee is presented together with a preliminary estimate of synchrotron radiation that affects this region. We describe in this paper the main guidelines of this design and the estimate of synchrotron radiation coming from the last bending magnets and from the final focus quadrupoles, with the software tools developed for this purpose. Here, the design follows the asymmetric optics layout as far as incoming bend radiation is concerned with the maximum foreseen beam energy of 175 GeV and we present a feasible initial layout with an indication ofmore » tolerable synchrotron radiation.« less

Machine detector interface studies: Layout and synchrotron radiation estimate in the future circular collider interaction region

DOE PAGES

Boscolo, Manuela; Burkhardt, Helmut; Sullivan, Michael

2017-01-27

The interaction region layout for the e +e – future circular collider FCC-ee is presented together with a preliminary estimate of synchrotron radiation that affects this region. We describe in this paper the main guidelines of this design and the estimate of synchrotron radiation coming from the last bending magnets and from the final focus quadrupoles, with the software tools developed for this purpose. Here, the design follows the asymmetric optics layout as far as incoming bend radiation is concerned with the maximum foreseen beam energy of 175 GeV and we present a feasible initial layout with an indication ofmore » tolerable synchrotron radiation.« less

Functional characterisation of metal(loid) processes in planta through the integration of synchrotron techniques and plant molecular biology

PubMed Central

Donner, Erica; Punshon, Tracy; Guerinot, Mary Lou; Lombi, Enzo

2013-01-01

Functional characterisation of the genes regulating metal(loid) homeostasis in plants is a major focus of crop biofortification, phytoremediation, and food security research. This paper focuses on the potential for advancing plant metal(loid) research by combining molecular biology and synchrotron-based techniques. Recent advances in x-ray focussing optics and fluorescence detection have greatly improved the potential of synchrotron techniques for plant science research, allowing metal(loids) to be imaged in vivo in hydrated plant tissues at sub-micron resolution. Laterally resolved metal(loid) speciation can also be determined. By using molecular techniques to probe the location of gene expression and protein localisation and combining it with this synchrotron-derived data, functional information can be effectively and efficiently assigned to specific genes. This paper provides a review of the state of the art in this field, and provides examples as to how synchrotron-based methods can be combined with molecular techniques to facilitate functional characterisation of genes in planta. PMID:22200921

Medical Applications of Synchrotron Radiation

NASA Astrophysics Data System (ADS)

Prezado, Yolanda; Martínez-Rovira, Immaculada

This chapter describes the state-of-art of synchrotron radiation therapies in the treatment of radioresistant tumors. The tolerance of the surrounding healthy tissue severely limits the achievement of a curative treatment for some brain tumors, like gliomas. This restriction is especially important in children, due to the high risk of complications in the development of the central nervous system. In addition, the treatment of tumors close to an organ at risk, like the spinal cord, is also restrained. One possible solution is the development of new radiotherapy techniques would exploit radically different irradiation modes, as it is the case of synchrotron radiotherapies. Their distinct features allow to modify the biological equivalent doses. In this chapter the three new approaches under development at the European Synchrotron Radiation Facility (ESRF), in Grenoble (France), will be described, namely: stereotactic synchrotron radiation therapy, microbeam radiation therapy and minibeam radiation therapy. The promising results obtained in the treatment of high grade brain tumors in preclinical studies have paved the way to the forthcoming clinical trials, currently in preparation.

POLARIMETRIC STUDIES OF MAGNETIC TURBULENCE WITH AN INTERFEROMETER

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Hyeseung; Cho, Jungyeon; Lazarian, A.

2016-11-01

We study statistical properties of synchrotron polarization emitted from media with magnetohydrodynamic (MHD) turbulence. We use both synthetic and MHD turbulence simulation data for our studies. We obtain the spatial spectrum and its derivative with respect to the wavelength of synchrotron polarization arising from both synchrotron radiation and Faraday rotation fluctuations. In particular, we investigate how the spectrum changes with frequency. We find that our simulations agree with the theoretical predication in Lazarian and Pogosyan. We conclude that the spectrum of synchrotron polarization and its derivative can be very informative tools to obtain detailed information about the statistical properties ofmore » MHD turbulence from radio observations of diffuse synchrotron polarization. They are especially useful for recovering the statistics of a turbulent magnetic field as well as the turbulent density of electrons. We also simulate interferometric observations that incorporate the effects of noise and finite telescope beam size, and demonstrate how we recover statistics of underlying MHD turbulence.« less

Fundamentals of Coherent Synchrotron Radiation in Storage Rings

NASA Astrophysics Data System (ADS)

Sannibale, F.; Byrd, J. M.; Loftsdottir, A.; Martin, M. C.; Venturini, M.

2004-05-01

We present the fundamental concepts for producing stable broadband coherent synchrotron radiation (CSR) in the terahertz frequency region in an electron storage ring. The analysis includes distortion of bunch shape from the synchrotron radiation (SR), enhancing higher frequency coherent emission and limits to stable emission due to a microbunching instability excited by the SR. We use these concepts to optimize the performance of a source for CSR emission.

Design of Synchrotron Light Source in Taiwan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuo, C. C.; Chang, H. P.; Chou, P. J.

2007-01-19

An intermediate energy synchrotron light source has been proposed. The goal is to construct a high performance light source in complementary to the existing 1.5 GeV synchrotron ring in Taiwan to boost the research capabilities. A 3 GeV machine with 518.4 m and 24-cell DBA lattice structure is considered and other options are also investigated. We report the 24-cell design considerations and its performances.

Wavelength dispersive analysis with the synchrotron x ray fluorescence microprobe

NASA Technical Reports Server (NTRS)

Rivers, M. L.; Thorn, K. S.; Sutton, S. R.; Jones, K. W.; Bajt, S.

1993-01-01

A wavelength dispersive spectrometer (WDS) was tested on the synchrotron x ray fluorescence microprobe at Brookhaven National Laboratory. Compared to WDS spectra using an electron microprobe, the synchrotron WDS spectra have much better sensitivity and, due to the absence of bremsstrahlung radiation, lower backgrounds. The WDS spectrometer was successfully used to resolve REE L fluorescence spectra from standard glasses and transition metal K fluorescence spectra from kamacite.

High density grids

DOEpatents

Cohen, Aina E.; Baxter, Elizabeth L.

2018-01-16

An X-ray data collection grid device is provided that includes a magnetic base that is compatible with robotic sample mounting systems used at synchrotron beamlines, a grid element fixedly attached to the magnetic base, where the grid element includes at least one sealable sample window disposed through a planar synchrotron-compatible material, where the planar synchrotron-compatible material includes at least one automated X-ray positioning and fluid handling robot fiducial mark.

Review of third and next generation synchrotron light sources

NASA Astrophysics Data System (ADS)

Bilderback, Donald H.; Elleaume, Pascal; Weckert, Edgar

2005-05-01

Synchrotron radiation (SR) is having a very large impact on interdisciplinary science and has been tremendously successful with the arrival of third generation synchrotron x-ray sources. But the revolution in x-ray science is still gaining momentum. Even though new storage rings are currently under construction, even more advanced rings are under design (PETRA III and the ultra high energy x-ray source) and the uses of linacs (energy recovery linac, x-ray free electron laser) can take us further into the future, to provide the unique synchrotron light that is so highly prized for today's studies in science in such fields as materials science, physics, chemistry and biology, for example. All these machines are highly reliant upon the consequences of Einstein's special theory of relativity. The consequences of relativity account for the small opening angle of synchrotron radiation in the forward direction and the increasing mass an electron gains as it is accelerated to high energy. These are familiar results to every synchrotron scientist. In this paper we outline not only the origins of SR but discuss how Einstein's strong character and his intuition and excellence have not only marked the physics of the 20th century but provide the foundation for continuing accelerator developments into the 21st century.

Science, Engineering, and Mathematics (SEM) at the Timbuktu Academy

DTIC Science & Technology

2005-07-31

School @ CalTech (PhD Chemistry Program) Millican , Jasmine F Su02 ONR 20 Fall `02- Grad . School @ LSU for Ph .D. in Chemistry, Baton Rouge, LA Thomas...n 22 . Joshua McKinsey Stennis Space Center - Stennis Space Center, M S 23 . Jasmine Millican Louisiana State University (LAMP Program) - Baton Rouge...OH 26. Rachel Mckinsey Fr ./Physics MIT- Boston, M A 27. Jasmine Millican Jr ./Chemistry University of Illinois - Chicago, I L 28. Symoane Mizell So

A Microcomputer-Based Program for Printing Check Plots of Integrated Circuits Specified in Caltech Intermediate Form.

DTIC Science & Technology

1984-12-01

only four transistors[5]. Each year since that time, the semiconductor industry has con- sistently improved the quality of the fabrication tech- niques...rarely took place at universities and was almost exclusively confined to industry . IC design techniques were developed, tested, and taught only in the...community, it is not uncommon for industry to borrow ideas and even particular programs from these university designed tools. The Very Large Scale Integration

Designing Networks that are Capable of Self-Healing and Adapting

DTIC Science & Technology

2017-04-01

Undergrad. Res. Fellowship, visiting from Caltech. Undergraduate Eugene Park Math Duke Models of self-healing networks (undergrad. senior thesis...Graduate student Anastasia Deckard Math Duke 3rd/4th year PhD. Wrote software for simulation. Undergraduate Nick Day Math LIMS Summer project at...Harer gave a talk on this DTRA grant to undergraduate math majors at Duke. 11 Q UA D C HA R T Uploaded to the DTRA Basic and Fundamental Research

Interferometry science center

NASA Technical Reports Server (NTRS)

Sargent, A. I.

2002-01-01

The Interferometry Science Center (ISC) is operated jointly by Caltech and JPL and is part of NASA's Navigator Program. The ISC has been created to facilitate the timely and successful execution of scientific investigations within the Navigator program, particularly those that rely on observations from NASA's interferometer projects. Currently, ISC is expected to provide full life cycle support for the Keck Interferometer, the Starlight mission, the Space Interferometry Mission, and the Terrestrial Planet Finder Mission. The nature and goals of ISc will be described.

(DURIP 10) High Speed Intensified Imaging System For Studies Of Mixing And Combustion In Supersonic Flows And Hydrocarbon Flame Structure Measurements At Elevated Pressures

DTIC Science & Technology

2016-11-09

software, and their networking to augment optical diagnostics employed in supersonic reacting and non-reacting flow experiments . A high-speed...facility at Caltech. Experiments to date have made use of this equipment, extending previous capabilities to high-speed schlieren quantitative flow...visualization and image correlation velocimetry, with further experiments currently in progress. 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF: 17

The Keck Cosmic Web Imager (KCWI): A Powerful New Integral Field Spectrograph for the Keck Observatory

NASA Astrophysics Data System (ADS)

Morrissey, Patrick; KCWI Team

2013-01-01

The Keck Cosmic Web Imager (KCWI) is a new facility instrument being developed for the W. M. Keck Observatory and funded for construction by the Telescope System Instrumentation Program (TSIP) of the National Science Foundation (NSF). KCWI is a bench-mounted spectrograph for the Keck II right Nasmyth focal station, providing integral field spectroscopy over a seeing-limited field up to 20"x33" in extent. Selectable Volume Phase Holographic (VPH) gratings provide high efficiency and spectral resolution in the range of 1000 to 20000. The dual-beam design of KCWI passed a Preliminary Design Review in summer 2011. The detailed design of the KCWI blue channel (350 to 700 nm) is now nearly complete, with the red channel (530 to 1050 nm) planned for a phased implementation contingent upon additional funding. KCWI builds on the experience of the Caltech team in implementing the Cosmic Web Imager (CWI), in operation since 2009 at Palomar Observatory. KCWI adds considerable flexibility to the CWI design, and will take full advantage of the excellent seeing and dark sky above Mauna Kea with a selectable nod-and-shuffle observing mode. The KCWI team is lead by Caltech (project management, design and implementation) in partnership with the University of California at Santa Cruz (camera optical and mechanical design) and the W. M. Keck Observatory (program oversight and observatory interfaces).

Context-aware and locality-constrained coding for image categorization.

PubMed

Xiao, Wenhua; Wang, Bin; Liu, Yu; Bao, Weidong; Zhang, Maojun

2014-01-01

Improving the coding strategy for BOF (Bag-of-Features) based feature design has drawn increasing attention in recent image categorization works. However, the ambiguity in coding procedure still impedes its further development. In this paper, we introduce a context-aware and locality-constrained Coding (CALC) approach with context information for describing objects in a discriminative way. It is generally achieved by learning a word-to-word cooccurrence prior to imposing context information over locality-constrained coding. Firstly, the local context of each category is evaluated by learning a word-to-word cooccurrence matrix representing the spatial distribution of local features in neighbor region. Then, the learned cooccurrence matrix is used for measuring the context distance between local features and code words. Finally, a coding strategy simultaneously considers locality in feature space and context space, while introducing the weight of feature is proposed. This novel coding strategy not only semantically preserves the information in coding, but also has the ability to alleviate the noise distortion of each class. Extensive experiments on several available datasets (Scene-15, Caltech101, and Caltech256) are conducted to validate the superiority of our algorithm by comparing it with baselines and recent published methods. Experimental results show that our method significantly improves the performance of baselines and achieves comparable and even better performance with the state of the arts.

Optics for MUSIC: a new (sub)millimeter camera for the Caltech Submillimeter Observatory

NASA Astrophysics Data System (ADS)

Sayers, Jack; Czakon, Nicole G.; Day, Peter K.; Downes, Thomas P.; Duan, Ran P.; Gao, Jiansong; Glenn, Jason; Golwala, Sunil R.; Hollister, Matt I.; LeDuc, Henry G.; Mazin, Benjamin A.; Maloney, Philip R.; Noroozian, Omid; Nguyen, Hien T.; Schlaerth, James A.; Siegel, Seth; Vaillancourt, John E.; Vayonakis, Anastasios; Wilson, Philip R.; Zmuidzinas, Jonas

2010-07-01

We will present the design and implementation, along with calculations and some measurements of the performance, of the room-temperature and cryogenic optics for MUSIC, a new (sub)millimeter camera we are developing for the Caltech Submm Observatory (CSO). The design consists of two focusing elements in addition to the CSO primary and secondary mirrors: a warm off-axis elliptical mirror and a cryogenic (4K) lens. These optics will provide a 14 arcmin field of view that is diffraction limited in all four of the MUSIC observing bands (2.00, 1.33, 1.02, and 0.86 mm). A cold (4K) Lyot stop will be used to define the primary mirror illumination, which will be maximized while keeping spillover at the sub 1% level. The MUSIC focal plane will be populated with broadband phased antenna arrays that efficiently couple to factor of (see manuscript) 3 in bandwidth,1, 2 and each pixel on the focal plane will be read out via a set of four lumped element filters that define the MUSIC observing bands (i.e., each pixel on the focal plane simultaneously observes in all four bands). Finally, a series of dielectric and metal-mesh low pass filters have been implemented to reduce the optical power load on the MUSIC cryogenic stages to a quasi-negligible level while maintaining good transmission in-band.

Phase transitions and melting on the Hugoniot of Mg2SiO4 forsterite: new diffraction and temperature results

NASA Astrophysics Data System (ADS)

Asimow, P. D.; Akin, M. C.; Homel, M.; Crum, R. S.; Pagan, D.; Lind, J.; Bernier, J.; Mosenfelder, J. L.; Dillman, A. M.; Lavina, B.; Lee, S.; Fat'yanov, O. V.; Newman, M. G.

2017-06-01

The phase transitions of forsterite under shock were studied by x-ray diffraction and pyrometry. Samples of 2 mm thick, near-full density (>98% TMD) polycrystalline forsterite were characterized by EBSD and computed tomography and shock compressed to 50 and 75 GPa by two-stage gas gun at the Dynamic Compression Sector, Advanced Photon Source, with diffraction imaged during compression and release. Changes in diffraction confirm a phase transition by 75 GPa. In parallel, single-crystal forsterite shock temperatures were taken from 120 to 210 GPa with improved absolute calibration procedures on the Caltech 6-channel pyrometer and two-stage gun and used to examine the interpretation of superheating and P-T slope of the liquid Hugoniot. This work performed under the auspices of the U.S. Department of Energy (DOE) by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344, supported in part by LLNL's LDRD program under Grants 15-ERD-012 and 16-ERD-010. The Dynamic Compression Sector (35) is supported by DOE / National Nuclear Security Administration under Award Number DE-NA0002442. This research used resources of the Advanced Photon Source, a U.S. DOE Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. Caltech lab supported by NSF EAR-1426526.

The Impact of and Lessons Learned from NITARP, the NASA/IPAC Teacher Archive Research Program

NASA Astrophysics Data System (ADS)

Rebull, L. M.; Nitarp Team

2014-07-01

NITARP, the NASA/IPAC Teacher Archive Research Program, gets teachers involved in authentic astronomical research. We partner small groups of educators with a professional astronomer mentor for a year-long original research project. The teams echo the entire research process, from writing a proposal, to doing the research, to presenting the results at an American Astronomical Society (AAS) meeting. The program runs from January through January. Applications are available annually in May and are due in September. The educators' experiences color their teaching for years to come, influencing hundreds of students per teacher. This program differs from other programs we know of that get real astronomy data into the classroom in three ways. First, each team works on an original, unique project. There are no canned labs here! Second, each team presents their results in posters in science sessions at an American Astronomical Society meeting alongside other researchers' work (participants are not given a “free pass” because they are educators or students). Third, the “product” is the scientific result, not any sort of curriculum packet. The teachers adapt their project and their experiences to fit in their classroom environment. NITARP changes the way teachers think about science and scientists. More information is available online at http://nitarp.ipac.caltech.edu/.

Satellite Radar Detects Damage from Sept. 2017 Chiapas, Mexico Quake

NASA Image and Video Library

2017-09-19

The Advanced Rapid Imaging and Analysis (ARIA) team at NASA's Jet Propulsion Laboratory in Pasadena, California, and Caltech, also in Pasadena, created this Damage Proxy Map (DPM) depicting areas of Southern Mexico that are likely damaged (shown by red and yellow pixels) from the magnitude 8.1 Chiapas earthquake of Sept. 7, 2017 (near midnight local time, early morning on Sept. 8 UTC). The map is derived from synthetic aperture radar (SAR) images from the Copernicus Sentinel-1A and Sentinel-1B satellites, operated by the European Space Agency (ESA). The images were taken before (Sept. 7, 2017 UTC) and after (Sept. 13, 2017 UTC) the earthquake. The map covers an area of 155 by 106 miles (250 by 170 kilometers). Each pixel measures about 33 yards (30 meters) across. The color variation from yellow to red indicates increasingly more significant ground surface change. Preliminary validation was done by comparing the SAR images to optical satellite imagery from DigitalGlobe. This damage proxy map should be used as guidance to identify damaged areas, and may be less reliable over vegetated areas. Sentinel-1 data were accessed through the Copernicus Open Access Hub. The image contains modified Copernicus Sentinel data (2017), processed by ESA and analyzed by the NASA-JPL/Caltech ARIA team. This research was carried out at JPL under a contract with NASA. https://photojournal.jpl.nasa.gov/catalog/PIA21956

Analysis of cortical bone porosity using synchrotron radiation microtomography to evaluate the effects of chemotherapy

NASA Astrophysics Data System (ADS)

Alessio, R.; Nogueira, L. P.; Salata, C.; Mantuano, A.; Almeida, A. P.; Braz, D.; de Almeida, C. E.; Tromba, G.; Barroso, R. C.

2015-11-01

Microporosities play important biologic and mechanical roles on health. One of the side effects caused by some chemotherapy drugs is the induction of amenorrhea, temporary or not, in premenopausal women, with a consequent decrease in estrogen production, which can lead to cortical bone changes. In the present work, the femur diaphysis of rats treated with chemotherapy drugs were evaluated by 3D morphometric parameters using synchrotron radiation microtomography. Control animals were also evaluated for comparison. The 3D tomographic images were obtained at the SYRMEP (SYnchrotron Radiation for MEdical Physics) beamline at the ELETTRA Synchrotron Laboratory in Trieste, Italy. Results showed significant differences in morphometric parameters measured from the 3D images of femur diaphysis of rats.

Updates on the African Synchrotron Light Source (AfLS) Project

NASA Astrophysics Data System (ADS)

Dobbins, Tabbetha; Mtingwa, Sekazi; Wague, Ahmadou; Connell, Simon; Masara, Brian; Ntsoane, Tshepo; Norris, Lawrence; Winick, Herman; Evans-Lutterodt, Kenneth; Hussein, Tarek; Maresha, Feene; McLaughlin, Krystle; Oladijo, Philip; Du Plessis, Esna; Murenzi, Romain; Reed, Kennedy; Sette, Francesco; Werin, Sverker; Dorfan, Jonathan; Yousef, Mohammad

Africa is the only habitable continent without a synchrotron light source. A full steering committee was elected at the African Light Source (AfLS) conference on November 16-20, 2015 at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France. The conference brought together African scientists, policy makers, and stakeholders to discuss a synchrotron light source in Africa. Firm outcomes of the Conference were a set of resolutions and a roadmap. Additionally, a collaborative proposal to promote Advanced Light Sources and crystallographic sciences in targeted regions of the world was submitted by the International Union of Pure and Applied Physics (IUPAP) and the International Union of Crystallography (IUCr) to the International Council for Science (ICSU). www.africanlightsource.org.

Limitation of the synchrotron radiation

NASA Astrophysics Data System (ADS)

Zhang, Jialu; Yang, Jianming

2001-06-01

In recent years, owing to the great success of the synchrotron radiation in contemporary astrophysical research, the abusive use of synchrotron radiation has been emerged. In this paper, we show that the traditional idea, "electrons with a power-law energy distribution certainly yield a power-law radiation spectrum", should be changed. If the magnetic field of the radiation region is not flat and straight, the synchro-curvature radiation, instead of the synchrotron radiation, should be used to get a real description. In a curved magnetic field, the resulting spectrum of electrons could obviously distinct from a power-law one. This means that the way of only adding many other mechanisms to a pure power-law spectrum to get the expected spectrum might not be reasonable.

The evolution of the FIGARO data reduction system

NASA Technical Reports Server (NTRS)

Shortridge, K.

1992-01-01

The Figaro data reduction system originated at Caltech around 1983. It was based on concepts being developed in the U.K. by the Starlink organization, particularly the use of hierarchical self-defining data structures and the abstraction of most user-interaction into a set of 'parameter system' routines. Since 1984 it has continued to be developed at AAO, in collaboration with Starlink and Caltech. It was adopted as Starlink's main spectroscopic data reduction package, although it is by no means limited to spectra; it has operations for images and data cubes and even a few (very specialized) for four-dimensional data hypercubes. It continued to be used at Caltech and will be used at the Keck. It is also in use at a variety of other organizations around the world. Figaro was originally a system for VMS Vaxes. Recently it was ported (at Caltech) to run on SUN's, and work is underway at the University of New South Wales on a DecStation version. It is hoped to coordinate all this work into a unified release, but coordination of the development of a system by organizations covering three continents poses a number of interesting administrative problems. The hierarchical data structures used by Figaro allow it to handle a variety of types of data, and to add new items to data structures. Error and data quality information was added to the basic file format used, error information being particularly useful for infrared data. Cooperating sets of programs can add specific sub-structures to data files to carry information that they understand (polarimetry data containing multiple data arrays, for example), without this affecting the way other programs handle the files. Complex instrument-specific ancillary information can be added to data files written at a telescope and can be used by programs that understand the instrumental details in order to produce properly calibrated data files. Once this preliminary data processing was done the resulting files contain 'ordinary' spectra or images that can be processed by programs that are not instrument-specific. The structures holding the instrumental information can then be discarded from the files. Much effort has gone into trying to make it easy to write Figaro programs; data access subroutines are now available to handle access to all the conventional items found in Figaro files (main data arrays, error information, quality information etc), and programs that only need to access such items can be very simple indeed. A large number of Figaro users do indeed write their own Figaro applications using these routines. The fact that Figaro programs are written as callable subroutines getting information from the user through a small set of parameter routines means that they can be invoked in numerous ways; they are normally linked and run as individual programs (called by a small main routine that is generated automatically), but are also available linked to run under the ADAM data acquisition system and there is an interface that lets them be called as part of a user-written Fortran program. The long-term future of Figaro probably depends to a large extent on how successfully it manages the transition from being a VMS-only system to being a multi-platform system.

Probes of turbulent driving mechanisms in molecular clouds from fluctuations in synchrotron intensity

NASA Astrophysics Data System (ADS)

Herron, C. A.; Federrath, C.; Gaensler, B. M.; Lewis, G. F.; McClure-Griffiths, N. M.; Burkhart, Blakesley

2017-04-01

Previous studies have shown that star formation depends on the driving of molecular cloud turbulence, and differences in the driving can produce an order of magnitude difference in the star formation rate. The turbulent driving is characterized by the parameter ζ, with ζ = 0 for compressive, curl-free driving (e.g. accretion or supernova explosions), and ζ = 1 for solenoidal, divergence-free driving (e.g. Galactic shear). Here we develop a new method to measure ζ from observations of synchrotron emission from molecular clouds. We calculate statistics of mock synchrotron intensity images produced from magnetohydrodynamic simulations of molecular clouds, in which the driving was controlled to produce different values of ζ. We find that the mean and standard deviation of the log-normalized synchrotron intensity are sensitive to ζ, for values of ζ between 0 (curl-free driving) and 0.5 (naturally mixed driving). We quantify the dependence of zeta on the direction of the magnetic field relative to the line of sight. We provide best-fitting formulae for ζ in terms of the log-normalized mean and standard deviation of synchrotron intensity, with which ζ can be determined for molecular clouds that have similar Alfvénic Mach number to our simulations. These formulae are independent of the sonic Mach number. Signal-to-noise ratios larger than 5, and angular resolutions smaller than 5 per cent of the cloud diameter, are required to apply these formulae. Although there are no firm detections of synchrotron emission from molecular clouds, by combining Green Bank Telescope and Very Large Array observations it should be possible to detect synchrotron emission from molecular clouds, thereby constraining the value of ζ.

Commissioning and Early Operation for the NSLS-II Booster RF System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marques, C.; Cupolo, J.; Davila, P.

2015-05-03

The National Synchrotron Light Source II (NSLS-II) at Brookhaven National Laboratory (BNL) is a third generation 3GeV, 500mA synchrotron light source. We discuss the booster synchrotron RF system responsible for providing power to accelerate an electron beam from 200MeV to 3GeV. The RF system design and construction are complete and is currently in the operational phase of the NSLS-II project. Preliminary operational data is also discussed.

Fluorescence tomography using synchrotron radiation at the NSLS

NASA Astrophysics Data System (ADS)

Boisseau, P.; Grodzins, L.

1987-03-01

Fluorescence tomography utilizing focussed, tunable, monoenergetic X-rays from synchrotron light sources hold the promise of a non-invasive analytic tool for studying trace elements in specimens, particularly biological, at spatial resolutions of the order of micrometers. This note reports an early test at the National Synchrotron Light Source at Brookhaven National Laboratories in which fluorescence tomographic scans were successfully made of trace elements of iron and titanium in NBS standard glass and in a bee.

RoboPol: the optical polarization of gamma-ray-loud and gamma-ray-quiet blazars

NASA Astrophysics Data System (ADS)

Angelakis, E.; Hovatta, T.; Blinov, D.; Pavlidou, V.; Kiehlmann, S.; Myserlis, I.; Böttcher, M.; Mao, P.; Panopoulou, G. V.; Liodakis, I.; King, O. G.; Baloković, M.; Kus, A.; Kylafis, N.; Mahabal, A.; Marecki, A.; Paleologou, E.; Papadakis, I.; Papamastorakis, I.; Pazderski, E.; Pearson, T. J.; Prabhudesai, S.; Ramaprakash, A. N.; Readhead, A. C. S.; Reig, P.; Tassis, K.; Urry, M.; Zensus, J. A.

2016-12-01

We present average R-band optopolarimetric data, as well as variability parameters, from the first and second RoboPol observing season. We investigate whether gamma-ray-loud and gamma-ray-quiet blazars exhibit systematic differences in their optical polarization properties. We find that gamma-ray-loud blazars have a systematically higher polarization fraction (0.092) than gamma-ray-quiet blazars (0.031), with the hypothesis of the two samples being drawn from the same distribution of polarization fractions being rejected at the 3σ level. We have not found any evidence that this discrepancy is related to differences in the redshift distribution, rest-frame R-band luminosity density, or the source classification. The median polarization fraction versus synchrotron-peak-frequency plot shows an envelope implying that high-synchrotron-peaked sources have a smaller range of median polarization fractions concentrated around lower values. Our gamma-ray-quiet sources show similar median polarization fractions although they are all low-synchrotron-peaked. We also find that the randomness of the polarization angle depends on the synchrotron peak frequency. For high-synchrotron-peaked sources, it tends to concentrate around preferred directions while for low-synchrotron-peaked sources, it is more variable and less likely to have a preferred direction. We propose a scenario which mediates efficient particle acceleration in shocks and increases the helical B-field component immediately downstream of the shock.

In-situ synchrotron wide-angle X-ray diffraction as a rapid method for cocrystal/salt screening.

PubMed

Dong, Pin; Lin, Ling; Li, Yongcheng; Huang, Zhengwei; Lang, Tianqun; Wu, Chuanbin; Lu, Ming

2015-12-30

The purpose of this work was to explore in-situ synchrotron wide-angle X-ray diffraction (WAXD) as a rapid and accurate tool to screen and monitor the formation of cocrystal/salts during heating. The active pharmaceutical ingredients (caffeine, carbamazepine and lamotrigine) were respectively mixed with the coformer (saccharin), and then heated by the hot stage. Real-time process monitoring was performed using synchrotron WAXD to assess cocrystal formation and subsequently compared to differential scanning calorimetry (DSC) measurements. The effect of heating rates and cocrystal growth behavior were investigated. Synchrotron WAXD was fast and sensitive to detect cocrystal formation with the appearance of characteristic diffraction rings, even at the heating rate of 30°C/min, while DSC curves showed overlapped peaks. Unlike the indirect characterization of DSC on endo/exothermic peaks, synchrotron WAXD can directly and qualitatively determine cocrystal by diffraction peaks. The diffraction intensity-temperature curves and the corresponding first-derivative curves clearly exhibited the growth behavior of cocrystal upon heating, providing useful information to optimize the process temperature of hot melt extrusion to continuously manufacture cocrystal. The study suggests that in-situ synchrotron WAXD could provide a one-step process to screen cocrystal at high efficiency and reveal the details of cocrystal/salts growth behavior. Copyright © 2015 Elsevier B.V. All rights reserved.

Optoelectronic Picosecond Detection of Synchrotron X-rays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Durbin, Stephen M.

2017-08-04

The goal of this research program was to develop a detector that would measure x-ray time profiles with picosecond resolution. This was specifically aimed for use at x-ray synchrotrons, where x-ray pulse profiles have Gaussian time spreads of 50-100 ps (FWHM), so the successful development of such a detector with picosecond resolution would permit x-ray synchrotron studies to break through the pulse width barrier. That is, synchrotron time-resolved studies are currently limited to pump-probe studies that cannot reveal dynamics faster than ~50 ps, whereas the proposed detector would push this into the physically important 1 ps domain. The results ofmore » this research effort, described in detail below, are twofold: 1) the original plan to rely on converting electronic signals from a semiconductor sensor into an optical signal proved to be insufficient for generating signals with the necessary time resolution and sensitivity to be widely applicable; and 2) an all-optical method was discovered whereby the x-rays are directly absorbed in an optoelectronic material, lithium tantalate, which can then be probed by laser pulses with the desired picosecond sensitivity for detection of synchrotron x-rays. This research program has also produced new fundamental understanding of the interaction of x-rays and optical lasers in materials that has now created a viable path for true picosecond detection of synchrotron x-rays.« less

Radiological considerations for bulk shielding calculations of national synchrotron light source-II

NASA Astrophysics Data System (ADS)

Job, Panakkal K.; Casey, William R.

2011-12-01

Brookhaven National Laboratory is designing a new electron synchrotron for scientific research using synchrotron radiation. This facility, called the “National Synchrotron Light Source II” (NSLS-II), will provide x-ray radiation of ultra-high brightness and exceptional spatial and energy resolution. It will also provide advanced insertion devices, optics, detectors and robotics, and a suite of scientific instruments designed to maximize the scientific output of the facility. The project scope includes the design, construction, installation, and commissioning of the following accelerators: a 200 MeV linac, a booster synchrotron operating from 200 MeV to 3.0 GeV, and the storage ring which stores a maximum of 500 mA current of electrons at an energy of 3.0 GeV. It is planned to operate the facility primarily in a top-off mode, thereby maintaining the maximum variation in stored beam current to <1%. Because of the very demanding requirements for beam emittance and synchrotron radiation brilliance, the beam life-time is expected to be quite low, on the order of 2 h. Analysis of the bulk shielding for operating this facility and the input parameters used for this analysis have been discussed in this paper. The characteristics of each of the accelerators and their operating modes have been summarized with the input assumptions for the bulk shielding analysis.

Impact Cratering Calculations

NASA Technical Reports Server (NTRS)

Ahrens, Thomas J.

2001-01-01

This research is computational /theoretical and complements the Caltech experimental program. We have developed an understanding of the basic physical processes and produced computational models and implemented these into Eulerian and Lagrangian finite element codes. The key issues we have addressed include the conditions required for: faulting (strain localization), elastic moduli weakening, dynamic weakening (layering elastic instabilities and fluidization), bulking (creation of porosity at zero pressure) and compaction of pores, frictional melting (creation of pseudotachylytes), partial and selective devolatilization of materials (e.g. CaCO3, water/ice mixtures), and debris flows.

Wide Field Infrared Survey Telescope [WFIRST]: Telescope Design and Simulated Performance

NASA Technical Reports Server (NTRS)

Goullioud, R.; Content, D. A.; Kuan, G. M.; Moore, J. D.; Chang, Z.; Sunada, E. T.; Villalvazo, J.; Hawk, J. P.; Armani, N. V.; Johnson, E. L.;

Streaming energetic electrons in earth's magnetotail - Evidence for substorm-associated magnetic reconnection

NASA Technical Reports Server (NTRS)

Bieber, J. W.; Stone, E. C.

1980-01-01

This letter reports the results of a systematic study of streaming greater than 200 keV electrons observed in the magnetotail with the Caltech Electron/Isotope Spectrometers aboard IMP-7 and IMP-8. A clear statistical association of streaming events with southward magnetic fields, often of steep inclination, and with substorms as evidenced by the AE index is demonstrated. These results support the interpretation that streaming energetic electrons are indicative of substorm-associated magnetic reconnection in the near-earth plasma sheet.

A Caltech MURI Center for Quantum Networks

DTIC Science & Technology

2006-05-31

the code. Thus the dimension of the code space is n5uPfAu5detD , ~64! where PfA denotes the Pfaffian, the square root of the deter- minant of the...material properties, such as bulk ab- sorption and surface scattering. However, as one moves to very small spheres with radius a&10 mm, the intrinsic...1550 nm, which yields a quality factor of Qbulk;3.8310 11. The quality factor due to surface scattering Qs.s. and ab- sorption by adsorbed water Qw has

Searching for Correlations with the HCO+ 4-3 Molecular Spectra of Protostars

NASA Astrophysics Data System (ADS)

Acikgoz, Ogulcan; Basturk, Seda

The assignment is based on HCO+ J=4-3 spectral line molecular observations of protostars from the James Clerk Maxwell Telescope, which has the 15 m diameter dish and located in Mauna Kea, Hawaii, USA. Data of 20 protostars are taken from the public LOMASS database and analyzed. We looked for correlations between a few observational quantities. We thank Dr Umut Yildiz (NASA/JPL-Caltech) for providing data and his comments and support to our research project.

Transition Delay in Hypervelocity Boundary Layers by Means of Vibrational Relaxation and Acoustic Instability Interactions

DTIC Science & Technology

2014-01-04

Ca, 93536 Stuart Laurence2, Amy War-Kei Beierholm3, Hans G. Hornung4 Caltech, Pasadena, Ca, 91125 and Ross Wagnild5, Graham Candler6 University...The shots refer to particular conditions tested in the T5 facility for a 45-degree swept cylinder. Taken from [10]. The theory of how relaxation...0. 25 14 /6 .2 00 9- 12 87 27 American Institute of Aeronautics and Astronautics 15 3 Mack, L.M., “Boundary-layer stability theory ,” In

Caltech Center for Structural and Amorphous Metals

DTIC Science & Technology

2005-05-10

Flores, D. Suh, R. Howell, P. Asoka -Kumar, P.A. Sterne, and R. H. Dauskardt, "Flow and Fracture of Bulk Metallic Glass Alloys and Their Composites...Behavior of Zr-Ti-Cu-Ni-Be Bulk Metallic Glass Alloys," Materials Transactions, JIM, 42 [4], 638-641, 2001. K. M. Flores, D. Suh, P. Asoka -Kumar, P.A...Materials Research, 17[5], 1153-1161, 2002. D. Suh, P. Asoka -Kumar and R. H. Dauskardt, "The Effects of Hydrogen on Viscoelastic Relaxation in Zr-Ti-Ni-Cu

Global Binary Continuity for Color Face Detection With Complex Background

NASA Astrophysics Data System (ADS)

Belavadi, Bhaskar; Mahendra Prashanth, K. V.; Joshi, Sujay S.; Suprathik, N.

2017-08-01

In this paper, we propose a method to detect human faces in color images, with complex background. The proposed algorithm makes use of basically two color space models, specifically HSV and YCgCr. The color segmented image is filled uniformly with a single color (binary) and then all unwanted discontinuous lines are removed to get the final image. Experimental results on Caltech database manifests that the purported model is able to accomplish far better segmentation for faces of varying orientations, skin color and background environment.

Book Review - Panofsky on Physics, Politics, and Peace: Pief Remembers

NASA Astrophysics Data System (ADS)

Loew, Gregory

The following sections are included: * Introduction: Genesis of the Book * Nature and Nurture: Pief's Early Life * This Review * High School in Hamburg; University at Princeton and Caltech * Pief and the Bomb * Accelerators and Physics at UCRL * Events Leading up to the Loyalty Oath * Stanford, the Microwave Lab and HEPL * The Rise of SLAC * Building SLAC * Physics Research at SLAC in the First Ten Years * Other Accelerator Activities under Pief * Science Advising and International Science * Arms Control (1981-2007): The Unfinished Business

A High-Mass Cold Core in the Auriga-California Giant Molecular Cloud

NASA Astrophysics Data System (ADS)

Magnus McGehee, Peregrine; Paladini, Roberta; Pelkonen, Veli-Matti; Toth, Viktor; Sayers, Jack

2015-08-01

The Auriga-California Giant Molecular Cloud is noted for its relatively low star formation rate, especially at the high-mass end of the Initial Mass Function. We combine maps acquired by the Caltech Submillimeter Observatory's Multiwavelength Submillimeter Inductance Camera [MUSIC] in the wavelength range 0.86 to 2.00 millimeters with Planck and publicly-available Herschel PACS and SPIRE data in order to characterize the mass, dust properties, and environment of the bright core PGCC G163.32-8.41.

The Antiaircraft Journal. Volume 92, Number 6, November-December 1949

DTIC Science & Technology

1949-12-01

nation’s peacetime history . Strategic plans for the nation’s defense are far advanced beyond those of any previous peacetime year . The Ameri- can people...From April through October of that year , activities of the OSRD Group such as Caltech were largely absorbed by the permanent teChnical organization of...with only four years ’ service is los - ing as many credits as a nonveteran might earn in twenty years of reserve component service. Title III, Public

Fluid Mixing in the Eye Under Rapid Eye Movement

NASA Astrophysics Data System (ADS)

Huang, Jinglin; Gharib, Morteza

2017-11-01

Drug injection is an important technique in certain treatments of eye diseases. The efficacy of chemical mixing plays an important role in determining pharmacokinetics of injected drugs. In this study, we build a device to study the chemical mixing behavior in a spherical structure. The mixing process is visualized and analyzed qualitatively. We hope to understand the chemical convection and diffusion behaviors in correlation with controlled rapid mechanical movements. The results will have potential applications in treatment of eye diseases. Resnick Institute at Caltech.

Evaluating scintillator performance in time-resolved hard X-ray studies at synchrotron light sources.

PubMed

Rutherford, Michael E; Chapman, David J; White, Thomas G; Drakopoulos, Michael; Rack, Alexander; Eakins, Daniel E

2016-05-01

The short pulse duration, small effective source size and high flux of synchrotron radiation is ideally suited for probing a wide range of transient deformation processes in materials under extreme conditions. In this paper, the challenges of high-resolution time-resolved indirect X-ray detection are reviewed in the context of dynamic synchrotron experiments. In particular, the discussion is targeted at two-dimensional integrating detector methods, such as those focused on dynamic radiography and diffraction experiments. The response of a scintillator to periodic synchrotron X-ray excitation is modelled and validated against experimental data collected at the Diamond Light Source (DLS) and European Synchrotron Radiation Facility (ESRF). An upper bound on the dynamic range accessible in a time-resolved experiment for a given bunch separation is calculated for a range of scintillators. New bunch structures are suggested for DLS and ESRF using the highest-performing commercially available crystal LYSO:Ce, allowing time-resolved experiments with an interframe time of 189 ns and a maximum dynamic range of 98 (6.6 bits).

Evaluating scintillator performance in time-resolved hard X-ray studies at synchrotron light sources

PubMed Central

Rutherford, Michael E.; Chapman, David J.; White, Thomas G.; Drakopoulos, Michael; Rack, Alexander; Eakins, Daniel E.

2016-01-01

The short pulse duration, small effective source size and high flux of synchrotron radiation is ideally suited for probing a wide range of transient deformation processes in materials under extreme conditions. In this paper, the challenges of high-resolution time-resolved indirect X-ray detection are reviewed in the context of dynamic synchrotron experiments. In particular, the discussion is targeted at two-dimensional integrating detector methods, such as those focused on dynamic radiography and diffraction experiments. The response of a scintillator to periodic synchrotron X-ray excitation is modelled and validated against experimental data collected at the Diamond Light Source (DLS) and European Synchrotron Radiation Facility (ESRF). An upper bound on the dynamic range accessible in a time-resolved experiment for a given bunch separation is calculated for a range of scintillators. New bunch structures are suggested for DLS and ESRF using the highest-performing commercially available crystal LYSO:Ce, allowing time-resolved experiments with an interframe time of 189 ns and a maximum dynamic range of 98 (6.6 bits). PMID:27140147

Optimizing a synchrotron based x-ray lithography system for IC manufacturing

NASA Astrophysics Data System (ADS)

Kovacs, Stephen; Speiser, Kenneth; Thaw, Winston; Heese, Richard N.

1990-05-01

The electron storage ring is a realistic solution as a radiation source for production grade, industrial X-ray lithography system. Today several large scale plans are in motion to design and implement synchrotron storage rings of different types for this purpose in the USA and abroad. Most of the scientific and technological problems related to the physics, design and manufacturing engineering, and commissioning of these systems for microlithography have been resolved or are under extensive study. However, investigation on issues connected to application of Synchrotron Orbit Radiation (SOR ) in chip production environment has been somewhat neglected. In this paper we have filled this gap pointing out direct effects of some basic synchrotron design parameters and associated subsystems (injector, X-ray beam line) on the operation and cost of lithography in production. The following factors were considered: synchrotron configuration, injection energy, beam intensity variability, number of beam lines and wafer exposure concept. A cost model has been worked out and applied to three different X-ray Lithography Source (XLS) systems. The results of these applications are compared and conclusions drawn.

Operation of the Australian Store.Synchrotron for macromolecular crystallography

PubMed Central

Meyer, Grischa R.; Aragão, David; Mudie, Nathan J.; Caradoc-Davies, Tom T.; McGowan, Sheena; Bertling, Philip J.; Groenewegen, David; Quenette, Stevan M.; Bond, Charles S.; Buckle, Ashley M.; Androulakis, Steve

2014-01-01

The Store.Synchrotron service, a fully functional, cloud computing-based solution to raw X-ray data archiving and dissemination at the Australian Synchrotron, is described. The service automatically receives and archives raw diffraction data, related metadata and preliminary results of automated data-processing workflows. Data are able to be shared with collaborators and opened to the public. In the nine months since its deployment in August 2013, the service has handled over 22.4 TB of raw data (∼1.7 million diffraction images). Several real examples from the Australian crystallographic community are described that illustrate the advantages of the approach, which include real-time online data access and fully redundant, secure storage. Discoveries in biological sciences increasingly require multidisciplinary approaches. With this in mind, Store.Synchrotron has been developed as a component within a greater service that can combine data from other instruments at the Australian Synchrotron, as well as instruments at the Australian neutron source ANSTO. It is therefore envisaged that this will serve as a model implementation of raw data archiving and dissemination within the structural biology research community. PMID:25286837

Operation of the Australian Store.Synchrotron for macromolecular crystallography.

PubMed

Meyer, Grischa R; Aragão, David; Mudie, Nathan J; Caradoc-Davies, Tom T; McGowan, Sheena; Bertling, Philip J; Groenewegen, David; Quenette, Stevan M; Bond, Charles S; Buckle, Ashley M; Androulakis, Steve

2014-10-01

The Store.Synchrotron service, a fully functional, cloud computing-based solution to raw X-ray data archiving and dissemination at the Australian Synchrotron, is described. The service automatically receives and archives raw diffraction data, related metadata and preliminary results of automated data-processing workflows. Data are able to be shared with collaborators and opened to the public. In the nine months since its deployment in August 2013, the service has handled over 22.4 TB of raw data (∼1.7 million diffraction images). Several real examples from the Australian crystallographic community are described that illustrate the advantages of the approach, which include real-time online data access and fully redundant, secure storage. Discoveries in biological sciences increasingly require multidisciplinary approaches. With this in mind, Store.Synchrotron has been developed as a component within a greater service that can combine data from other instruments at the Australian Synchrotron, as well as instruments at the Australian neutron source ANSTO. It is therefore envisaged that this will serve as a model implementation of raw data archiving and dissemination within the structural biology research community.

Next-generation materials for future synchrotron and free-electron laser sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Assoufid, Lahsen; Graafsma, Heinz

We show that the development of new materials and improvements of existing ones are at the root of the spectacular recent developments of new technologies for synchrotron storage rings and free-electron laser sources. This holds true for all relevant application areas, from electron guns to undulators, x-ray optics, and detectors. As demand grows for more powerful and efficient light sources, efficient optics, and high-speed detectors, an overview of ongoing materials research for these applications is timely. In this article, we focus on the most exciting and demanding areas of materials research and development for synchrotron radiation optics and detectors. Materialsmore » issues of components for synchrotron and free-electron laser accelerators are briefly discussed. Lastly, the articles in this issue expand on these topics.« less

Next-generation materials for future synchrotron and free-electron laser sources

DOE PAGES

Assoufid, Lahsen; Graafsma, Heinz

2017-06-09

We show that the development of new materials and improvements of existing ones are at the root of the spectacular recent developments of new technologies for synchrotron storage rings and free-electron laser sources. This holds true for all relevant application areas, from electron guns to undulators, x-ray optics, and detectors. As demand grows for more powerful and efficient light sources, efficient optics, and high-speed detectors, an overview of ongoing materials research for these applications is timely. In this article, we focus on the most exciting and demanding areas of materials research and development for synchrotron radiation optics and detectors. Materialsmore » issues of components for synchrotron and free-electron laser accelerators are briefly discussed. Lastly, the articles in this issue expand on these topics.« less

Properties of Blazar Jets Defined by an Economy of Power

NASA Astrophysics Data System (ADS)

Petropoulou, Maria; Dermer, Charles D.

2016-07-01

The absolute power of a relativistic black hole jet includes the power in the magnetic field, the leptons, the hadrons, and the radiated photons. A power analysis of a relativistic radio/γ-ray blazar jet leads to bifurcated leptonic synchrotron-Compton (LSC) and leptohadronic synchrotron (LHS) solutions that minimize the total jet power. Higher Doppler factors with increasing peak synchrotron frequency are implied in the LSC model. Strong magnetic fields {B}\\prime ≳ 100 {{G}} are found for the LHS model with variability times ≲ {10}3 {{s}}, in accord with highly magnetized, reconnection-driven jet models. Proton synchrotron models of ≳ 100 {GeV} blazar radiation can have sub-Eddington absolute jet powers, but models of dominant GeV radiation in flat spectrum radio quasars require excessive power.

Novel portable press for synchrotron time-resolved 3-D micro-imagining under extreme conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Philippe, J.; Le Godec, Y., E-mail: yann.legodec@impmc.upmc.fr; Bergame, F.

Here we present the instrumental development to extend the synchrotron X-ray microtomography techniques to in situ studies under static compression (HP) or shear stress or the both conditions at high temperatures (HT). To achieve this, a new rotating tomography Paris-Edinburgh cell (rotoPEc) has been developed. This ultra-compact portable device, easily and successfully adapted to various multi-modal synchrotron experimental set-up at ESRF, SOLEIL and DIAMOND is explained in detail.

Dynamical diffraction imaging (topography) with X-ray synchrotron radiation

NASA Technical Reports Server (NTRS)

Kuriyama, M.; Steiner, B. W.; Dobbyn, R. C.

1989-01-01

By contrast to electron microscopy, which yields information on the location of features in small regions of materials, X-ray diffraction imaging can portray minute deviations from perfect crystalline order over larger areas. Synchrotron radiation-based X-ray optics technology uses a highly parallel incident beam to eliminate ambiguities in the interpretation of image details; scattering phenomena previously unobserved are now readily detected. Synchrotron diffraction imaging renders high-resolution, real-time, in situ observations of materials under pertinent environmental conditions possible.

SYNCHROTRON RADIATION, FREE ELECTRON LASER, APPLICATION OF NUCLEAR TECHNOLOGY, ETC.: Study on the characteristics of linac based THz light source

NASA Astrophysics Data System (ADS)

Zhu, Xiong-Wei; Wang, Shu-Hong; Chen, Sen-Yu

2009-10-01

There are many methods based on linac for THz radiation production. As one of the options for the Beijing Advanced Light, an ERL test facility is proposed for THz radiation. In this test facility, there are 4 kinds of methods to produce THz radiation: coherent synchrotron radiation (CSR), synchrotron radiation (SR), low gain FEL oscillator, and high gain SASE FEL. In this paper, we study the characteristics of the 4 kinds of THz light sources.

National Synchrotron Light Source annual report 1988

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hulbert, S.; Lazarz, N.; Williams, G.

1988-01-01

This report discusses the experiment done at the National Synchrotron Light Source. Most experiments discussed involves the use of the x-ray beams to study physical properties of solid materials. (LSP)

Synchrotron radiation X-ray microtomography and histomorphometry for evaluation of chemotherapy effects in trabecular bone structure

NASA Astrophysics Data System (ADS)

Alessio, R.; Nogueira, L. P.; Almeida, A. P.; Colaço, M. V.; Braz, D.; Andrade, C. B. V.; Salata, C.; Ferreira-Machado, S. C.; de Almeida, C. E.; Tromba, G.; Barroso, R. C.

2014-04-01

Three-dimensional microtomography has the potential to examine complete bones of small laboratory animals with very high resolution in a non-invasive way. One of the side effects caused by some chemotherapy drugs is the induction of amenorrhea, temporary or not, in premenopausal women, with a consequent decrease in estrogen production, which can lead to bone changes. In the present work, the femur heads of rats treated with chemotherapy drugs were evaluated by 3D histomorphometry using synchrotron radiation microcomputed tomography. Control animals were also evaluated for comparison. The 3D tomographic images were obtained at the SYRMEP (SYnchrotron Radiation for MEdical Physics) beamline at the Elettra Synchrotron Laboratory in Trieste, Italy. Results showed significant differences in morphometric parameters measured from the 3D images of femur heads of rats in both analyzed groups.

Synchrotron X-ray microfluorescence measurement of metal distributions in Phragmites australis root system in the Yangtze River intertidal zone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feng, Huan; Zhang, Weiguo; Qian, Yu

2016-06-15

This study investigates the distributions of Br, Ca, Cl, Cr, Cu, K, Fe, Mn, Pb, Ti, V and Zn inPhragmites australisroot system and the function of Fe nanoparticles in scavenging metals in the root epidermis using synchrotron X-ray microfluorescence, synchrotron transmission X-ray microscope measurement and synchrotron X-ray absorption near-edge structure techniques. The purpose of this study is to understand the mobility of metals in wetland plant root systems after their uptake from rhizosphere soils.Phragmites australissamples were collected in the Yangtze River intertidal zone in July 2013. The results indicate that Fe nanoparticles are present in the root epidermis and thatmore » other metals correlate significantly with Fe, suggesting that Fe nanoparticles play an important role in metal scavenging in the epidermis.« less

Reciprocal Space Mapping of Macromolecular Crystals in the Home Laboratory

NASA Technical Reports Server (NTRS)

Snell, Edward H.; Fewster, P. F.; Andrew, Norman; Boggon, T. J.; Judge, Russell A.; Pusey, Marc A.

1999-01-01

Reciprocal space mapping techniques are used widely by the materials science community to provide physical information about their crystal samples. We have used similar methods at synchrotron sources to look at the quality of macromolecular crystals produced both on the ground and under microgravity conditions. The limited nature of synchrotron time has led us to explore the use of a high resolution materials research diffractometer to perform similar measurements in the home laboratory. Although the available intensity is much reduced due to the beam conditioning necessary for high reciprocal space resolution, lower resolution data can be collected in the same detail as the synchrotron source. Experiments can be optimized at home to make most benefit from the synchrotron time available. Preliminary results including information on the mosaicity and the internal strains from reciprocal space maps will be presented.

Chemical applications of synchrotron radiation: Workshop report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1989-04-01

The most recent in a series of topical meetings for Advanced Photon Source user subgroups, the Workshop on Chemical Applications of Synchrotron Radiation (held at Argonne National Laboratory, October 3-4, 1988) dealt with surfaces and kinetics, spectroscopy, small-angle scattering, diffraction, and topography and imaging. The primary objectives were to provide an educational resource for the chemistry community on the scientific research being conducted at existing synchrotron sources and to indicate some of the unique opportunities that will be made available with the Advanced Photon Source. The workshop organizers were also interested in gauging the interest of chemists in the fieldmore » of synchrotron radiation. Interest expressed at the meeting has led to initial steps toward formation of a Chemistry Users Group at the APS. Individual projects are processed separately for the data bases.« less

Converting Advances in Seismology into Earthquake Science

NASA Astrophysics Data System (ADS)

Hauksson, Egill; Shearer, Peter; Vidale, John

2004-01-01

Federal and state agencies and university groups all operate seismic networks in California. The U.S. Geological Survey (USGS) operates seismic networks in California in cooperation with the California Institute of Technology (Caltech) in southern California, and the University of California (UC) at Berkeley in northern California. The California Geological Survey (CGS) and the USGS National Strong Motion Program (NSMP) operate dial-out strong motion instruments in the state, primarily to capture data from large earthquakes for earthquake engineering and, more recently, emergency response. The California Governor's Office of Emergency Services (OES) provides leadership for the most recent project, the California Integrated Seismic Network (CISN), to integrate all of the California efforts, and to take advantage of the emergency response capabilities of the seismic networks. The core members of the CISN are Caltech, UC Berkeley, CGS, USGS Menlo Park, and USGS Pasadena (http://www.cisn.org). New seismic instrumentation is in place across southern California, and significant progress has been made in improving instrumentation in northern California. Since 2001, these new field instrumentation efforts, data sharing, and software development for real-time reporting and archiving have been coordinated through the California Integrated Seismic Network (CISN). The CISN is also the California region of the Advanced National Seismic Network (ANSS). In addition, EarthScope deployments of USArray that will begin in early 2004 in California are coordinated with the CISN. The southern and northern California earthquake data centers (SCEDC and NCEDC) have new capabilities that enable seismologists to obtain large volumes of data with only modest effort.

TOASTing Your Images With Montage

NASA Astrophysics Data System (ADS)

Berriman, G. Bruce; Good, John

2017-01-01

The Montage image mosaic engine is a scalable toolkit for creating science-grade mosaics of FITS files, according to the user's specifications of coordinates, projection, sampling, and image rotation. It is written in ANSI-C and runs on all common *nix-based platforms. The code is freely available and is released with a BSD 3-clause license. Version 5 is a major upgrade to Montage, and provides support for creating images that can be consumed by the World Wide Telescope (WWT). Montage treats the TOAST sky tessellation scheme, used by the WWT, as a spherical projection like those in the WCStools library. Thus images in any projection can be converted to the TOAST projection by Montage’s reprojection services. These reprojections can be performed at scale on high-performance platforms and on desktops. WWT consumes PNG or JPEG files, organized according to WWT’s tiling and naming scheme. Montage therefore provides a set of dedicated modules to create the required files from FITS images that contain the TOAST projection. There are two other major features of Version 5. It supports processing of HEALPix files to any projection in the WCS tools library. And it can be built as a library that can be called from other languages, primarily Python. http://montage.ipac.caltech.edu.GitHub download page: https://github.com/Caltech-IPAC/Montage.ASCL record: ascl:1010.036. DOI: dx.doi.org/10.5281/zenodo.49418 Montage is funded by the National Science Foundation under Grant Number ACI-1440620,

T(T,4He)2n and 3He(3He,4He)2p Reactions and the Energy Dependence of Their Mechanisms

NASA Astrophysics Data System (ADS)

Bacher, Andrew; McNabb, Dennis; Brune, Carl; Sayre, Dan; Hale, Gerry; Frenje, Johan; Gatu Johnson, Maria

2015-10-01

We have studied the T(T,alpha)2n reaction because it is the charge symmetric analog to the 3He(3He,alpha)2p reaction which completes the most direct mode of the p-p chain in stellar interiors. These reactions lead to three-body final states whose energy spectrum shapes are dominated by the strong nucleon-alpha interaction and the weaker nucleon-nucleon interaction. These experiments were done at OMEGA at the University of Rochester and at the NIF at Lawrence Livermore Lab. We will focus on two features: (1) the excitation energy dependence of the reaction mechanism and (2) the center-of-mass energy dependence of the reaction mechanism. At stellar energies (OMEGA and the NIF) we find that the shape of the neutron spectrum peaks in the middle. The n-alpha 1/2-excited state is about two times stronger than the n-alpha 3/2-ground state. For the 3He+3He reaction (at CalTech), the proton spectrum peaks at the high end. The p-alpha 3/2-state is about two times stronger than the 1/2-state. This difference in the spectrum shape is explained by theoretical models which include the interference between the two identical fermions in the final state. At CalTech we have angular distributions of the 3He+3He reaction from 2 MeV to 18 MeV. We see the p-wave strength increasing.

Dominica Hurricane Damage Mapped by NASA's ARIA Team

NASA Image and Video Library

2017-09-29

The Advanced Rapid Imaging and Analysis (ARIA) team at NASA's Jet Propulsion Laboratory in Pasadena, California, and Caltech, also in Pasadena, created this Damage Proxy Map (DPM) depicting areas including the Commonwealth of Dominica, that are likely damaged (shown by red and yellow pixels) as a result of Hurricane Maria (a Category 5 storm at landfall in Dominica on Sept. 18, 2017). The map is derived from synthetic aperture radar (SAR) images from the Copernicus Sentinel-1 satellites, operated by the European Space Agency (ESA). The images were taken before (March 27, 2017) and after (Sept. 23, 2017) the landfall of the storm. The map covers the area within the large red polygon, which measures 53 by 106 miles (85 by 170 kilometers). Each pixel measures about 98 feet (30 meters) across. The color variation from yellow to red indicates increasingly more significant ground surface change. Preliminary validation was done by comparing the data to a crowdsourced map by Clemson Center for Geospatial Technologies and optical satellite imagery feom DigitalGlobe. This damage proxy map should be used as guidance to identify damaged areas, and may be less reliable over vegetated areas. Sentinel-1 data were accessed through the Copernicus Open Access Hub. The image contains modified Copernicus Sentinel data (2017), processed by ESA and analyzed by the NASA/JPL-Caltech ARIA team. This research was carried out at JPL under a contract with NASA. https://photojournal.jpl.nasa.gov/catalog/PIA22037

Is Your Gut Conscious? Is an Extraterrestrial?

NASA Astrophysics Data System (ADS)

Vos Post, Jonathan

2011-10-01

This paper speculates on questions intending to be taken scientifically rather than metaphysically: "Can the human gut (enteric nervous system) be conscious?"; "Can your immune system think?"; "Could consciousness be coded in DNA?"; "What do we mean when asserting that an Extraterrestrial is Thinking, or is Conscious? We explore through reference to theory, experiment, and computational models by Christof Koch (Caltech), Barbara Wold (Caltech), and Stuart Kauffman (University of Calgary, Tampere University of Technology, Santa Fe Institute). We use a tentative new definition of thinking, designed to be applicable for humans, cetecea, corvids, artificial intelligences, and extraterrestrial intelligences of any substrate (i.e. Life as We Do Not Know It): "Thinking is the occurrence, transformation, and storage in a mind or brain (or simulation thereof) of information-bearing structures (representations) of one kind or another, such as thoughts, concept, percepts, ideas, impressions, notions, rules, schemas, images, phantasms, or subpersonal representations." We use the framework for Consciousness developed by Francis Crick and Christof Koch. We try to describe scientific goals, but discuss Philosophy sufficient to avoid naïve philosophical category errors (thus are careful not to conflate thought, consciousness, and language) Penrose, Hameroff, and Kauffman speculate (differently) that CNS consciousness is a macroscopic quantum phenomenon. Might intestinal, immune system, or genetic regulatory network dynamics exhibit emergent cooperative quantum effects? The speculations are in the context of Evolution by Natural Selection, presumed to operate throughout the Cosmos, and recent work in the foundations of Computational Biology and Quantum Mechanics.

VizieR Online Data Catalog: Star formation in active and normal galaxies (Tsai+, 2015)

NASA Astrophysics Data System (ADS)

Tsai, M.; Hwang, C.-Y.

2015-11-01

We selected 104 active galaxies from the lists of Melendez et al. (2010MNRAS.406..493M), Condon et al. 1991 (cat. J/ApJ/378/65), and Ho & Ulvestad 2001 (cat. J/ApJS/133/77). Most of the sources are identified as Active Galactic Nuclei (AGNs), and a few of them are classified as Luminous InfraRed Galaxies (LIRGs). We obtained 3.6 and 8μm infrared images of these galaxies from the Spitzer Archive (http://sha.ipac.caltech.edu/applications/Spitzer/SHA/) and 8GHz images from the VLA archive (http://archive.nrao.edu/archive/archiveimage.html). We also selected a nearby AGN sub-sample containing 21 radio-selected AGNs for further spatial analysis. We selected 25 nearby AGNs exhibiting no detected radio emission in order to compare with the results of the radio-selected sources. For comparison, we also selected normal galaxies with distances less than 15Mpc from the catalog of Tully 1994 (see cat. VII/145). We only selected the galaxies that have Spitzer archive data and are not identified as AGNs in either the Veron-Cetty & Veron 2006 (see cat. VII/258) AGN catalog or in the NED database (http://ned.ipac.caltech.edu/). Our results for the radio-selected and the non-radio-selected active galaxies are listed in Table1, and those for the normal galaxies are listed in Table2. (2 data files).

Repurposing the Caltech Robinson Hall Coelostat

NASA Astrophysics Data System (ADS)

Treffers, Richard R.; Loisos, G.; Ubbelohde, M.; Douglas, S.; Martinez, M.

2013-01-01

We describe the repurposing of the historic coelostat atop Caltech’s Robinson Hall for building lighting, public education and scientific research. The coelostat was originally part of George Ellery Hale’s vision of the Astrophysical Laboratory on the Caltech campus in 1932. The coelostat, designed by Russell Porter, has a 36 inch diameter primary mirror a 30 inch diameter secondary mirror and provides a 24 inch un-vignetted beam of sunlight into the building. Although constructed in the 1930s, due to wartime pressures and other projects, it was used only briefly in the 1970s and never fully realized. Recently Robinson Hall has been fully renovated to house the Ronald and Maxine Linde Center for Global Environmental Science. The coelostat operation was modernized replacing the old motors and automating all the motions. Each morning, if the weather cooperates, the dome slit opens, the mirrors configured and sunlight pours into the building. The beam of sunlight is divided into three parts. One part goes into a refracting telescope which projects a ten inch diameter of the sun onto a ground glass screen visible to the public. A second fraction is distributed to fiber optic fixtures that illuminate some of the basement rooms. The final fraction goes into two laboratories where it is used in experiments monitoring trace constituents of our atmosphere and for solar catalysis experiments. The instrument as originally conceived required at least two human operators. Now it is fully automatic and doing real science

GOSAT field experiments with a new portable mid-IR FTS in the western US

NASA Astrophysics Data System (ADS)

Shiomi, K.; Kikuchi, N.; Kuze, A.; Suto, H.; Kawakami, S.; Hashimoto, M.; Kataoka, F.; Kasai, K.; Arai, T.; Hedelius, J.; Viatte, C.; Wennberg, P. O.; Roehl, C. M.; Leifer, I.; Yates, E. L.; Marrero, J. E.; Iraci, L. T.; Bruegge, C. J.; Schwandner, F. M.; Crisp, D.

2016-12-01

The column-average dry air mole fractions of carbon dioxide (XCO2), methane (XCH4) and carbon monoxide (XCO) were measured from the surface using direct sunlight at near-IR wavelengths. Simultaneous detection of CO is helpful to characterize CO2 source type. We measured XCO along with XCO2 and XCH4 using a new portable Fourier transform spectrometer (FTS), EM27/SUN mid-IR,in western US field experiments at 1) Caltech, in Pasadena, a northern Los Angeles suburb, 2) Chino, a dairy farming region east of Los Angeles, and 3) Railroad Valley (RRV), a desert playa in Nevada. These measurements were conducted during the GOSAT/OCO-2 joint campaign for vicarious calibration and validation (cal/val) and its preparatory experiments in the early summer of 2016. Before the campaign, measurements from the JAXA EM27/SUN mid-IR were compared with those from the Total Carbon Column Observing Network (TCCON) station at Caltech. Then, we observed a diurnal cycle at the Chino dairy site, an area of concentrated animal husbandry, producing a CH4 point source. Finally, we conducted the cal/val campaign at RRV coincident with GOSAT and OCO-2 overpass observations. Over RRV, in-situ vertical profiles of CO2 and CH4 were measured using the Alpha Jet research aircraft as a part of the NASA Ames Alpha Jet Atmospheric eXperiment (AJAX). We will compare experimental results from the cal/val campaign for XCO2 and XCH4 with the portable FTS.

New expansion rate measurements of the Crab nebula in radio and optical

NASA Astrophysics Data System (ADS)

Bietenholz, M. F.; Nugent, R. L.

2015-12-01

We present new radio measurements of the expansion rate of the Crab nebula's synchrotron nebula over a ˜30-yr period. We find a convergence date for the radio synchrotron nebula of CE 1255 ± 27. We also re-evaluated the expansion rate of the optical-line-emitting filaments, and we show that the traditional estimates of their convergence date are slightly biased. Using an unbiased Bayesian analysis, we find a convergence date for the filaments of CE 1091 ± 34 (˜40 yr earlier than previous estimates). Our results show that both the synchrotron nebula and the optical-line-emitting filaments have been accelerated since the explosion in CE 1054, but that the synchrotron nebula has been relatively strongly accelerated, while the optical filaments have been only slightly accelerated. The finding that the synchrotron emission expands more rapidly than the filaments supports the picture that the latter are the result of the Rayleigh-Taylor instability at the interface between the pulsar-wind nebula and the surrounding freely expanding supernova ejecta, and rules out models where the pulsar-wind bubble is interacting directly with the pre-supernova wind of the Crab's progenitor.

Industry-relevant magnetron sputtering and cathodic arc ultra-high vacuum deposition system for in situ x-ray diffraction studies of thin film growth using high energy synchrotron radiation.

PubMed

Schroeder, J L; Thomson, W; Howard, B; Schell, N; Näslund, L-Å; Rogström, L; Johansson-Jõesaar, M P; Ghafoor, N; Odén, M; Nothnagel, E; Shepard, A; Greer, J; Birch, J

2015-09-01

We present an industry-relevant, large-scale, ultra-high vacuum (UHV) magnetron sputtering and cathodic arc deposition system purposefully designed for time-resolved in situ thin film deposition/annealing studies using high-energy (>50 keV), high photon flux (>10(12) ph/s) synchrotron radiation. The high photon flux, combined with a fast-acquisition-time (<1 s) two-dimensional (2D) detector, permits time-resolved in situ structural analysis of thin film formation processes. The high-energy synchrotron-radiation based x-rays result in small scattering angles (<11°), allowing large areas of reciprocal space to be imaged with a 2D detector. The system has been designed for use on the 1-tonne, ultra-high load, high-resolution hexapod at the P07 High Energy Materials Science beamline at PETRA III at the Deutsches Elektronen-Synchrotron in Hamburg, Germany. The deposition system includes standard features of a typical UHV deposition system plus a range of special features suited for synchrotron radiation studies and industry-relevant processes. We openly encourage the materials research community to contact us for collaborative opportunities using this unique and versatile scientific instrument.

Panchromatic Observations of GRB 110205A and Other GRB Optical Prompt Observations Obtained by ROTSE

NASA Astrophysics Data System (ADS)

Zheng, Weikang; with a larger Collaboration

2011-09-01

The leading radiation mechanisms for gamma-ray bursts (GRBs), as predicted by the standard GRB fireball model, include synchrotron radiation, synchrotron self-Compton (SSC), and inverse Compton scattering from thermal photons. Panchromatic observations during GRB prompt emission are important to distinguish the mechanisms. GRB 110205A, triggered by Swift, is also detected by Suzaku, ROTSE-IIIb and BOOTES telescopes when the GRB is still radiating gamma-rays. These panchromatic observations, covering 6 orders of energy range from 1 eV to 5 MeV, will be presented. We clearly discover an interesting two-break energy spectrum for the first time, roughly consistent with the synchrotron spectrum predicted by the standard GRB fireball model. The two break energies can be explained as νc, the synchrotron cooling frequency, and νm, the synchrotron typical frequency. With a sample of GRBs with optical prompt detections from ROTSE observations, one can also constrain the self-absorption frequency, νa. These detailed prompt observations are important to discriminate different mechanisms and thus lead us to a better and deeper understanding of the GRB fireball model. This research is supported by the NASA grant NNX08AV63G and the NSF grant PHY-0801007.

Synchrotron X-ray emission from old pulsars

NASA Astrophysics Data System (ADS)

Kisaka, Shota; Tanaka, Shuta J.

2014-09-01

We study the synchrotron radiation as the observed non-thermal emission by the X-ray satellites from old pulsars (≳1-10 Myr) to investigate the particle acceleration in their magnetospheres. We assume that the power-law component of the observed X-ray spectra is caused by the synchrotron radiation from electrons and positrons in the magnetosphere. We consider two pair-production mechanisms of X-ray emitting particles, the magnetic and the photon-photon pair productions. High-energy photons, which ignite the pair production, are emitted via the curvature radiation of the accelerated particles. We use the analytical description for the radiative transfer and estimate the luminosity of the synchrotron radiation. We find that for pulsars with the spin-down luminosity Lsd ≲ 1033 erg s-1, the locations of the particle acceleration and the non-thermal X-ray emission are within ≲107 cm from the centre of the neutron star, where the magnetic pair production occurs. For pulsars with the spin-down luminosity Lsd ≲ 1031 erg s-1 such as J0108-1431, the synchrotron radiation is difficult to explain the observed non-thermal component even if we consider the existence of the strong and small-scale surface magnetic field structures.

Assessing noise sources at synchrotron infrared ports

PubMed Central

Lerch, Ph.; Dumas, P.; Schilcher, T.; Nadji, A.; Luedeke, A.; Hubert, N.; Cassinari, L.; Boege, M.; Denard, J.-C.; Stingelin, L.; Nadolski, L.; Garvey, T.; Albert, S.; Gough, Ch.; Quack, M.; Wambach, J.; Dehler, M.; Filhol, J.-M.

2012-01-01

Today, the vast majority of electron storage rings delivering synchrotron radiation for general user operation offer a dedicated infrared port. There is growing interest expressed by various scientific communities to exploit the mid-IR emission in microspectroscopy, as well as the far infrared (also called THz) range for spectroscopy. Compared with a thermal (laboratory-based source), IR synchrotron radiation sources offer enhanced brilliance of about two to three orders of magnitude in the mid-IR energy range, and enhanced flux and brilliance in the far-IR energy range. Synchrotron radiation also has a unique combination of a broad wavelength band together with a well defined time structure. Thermal sources (globar, mercury filament) have excellent stability. Because the sampling rate of a typical IR Fourier-transform spectroscopy experiment is in the kHz range (depending on the bandwidth of the detector), instabilities of various origins present in synchrotron radiation sources play a crucial role. Noise recordings at two different IR ports located at the Swiss Light Source and SOLEIL (France), under conditions relevant to real experiments, are discussed. The lowest electron beam fluctuations detectable in IR spectra have been quantified and are shown to be much smaller than what is routinely recorded by beam-position monitors. PMID:22186638

Is the GeV-TeV emission of PKS 0447-439 from the proton synchrotron radiation?

NASA Astrophysics Data System (ADS)

Gao, Quan-Gui; Lu, Fang-Wu; Ma, Ju; Ren, Ji-Yang; Li, Huai-Zhen

2018-06-01

We study the multi-wavelength emission features of PKS 0447-439 in the frame of the one-zone homogeneous lepto-hadronic model. In this model, we assumed that the steady power-laws with exponential cut-offs distributions of protons and electrons are injected into the source. The non-linear time-dependent kinematic equations, describing the evolution of protons, electrons and photons, are defined; these equations self-consistently involve synchrotron radiation of protons, photon-photon interaction, synchrotron radiation of electron/positron pairs, inverse Compton scattering and synchrotron self-absorption. The model is applied to reproduce the multi-wavelength spectrum of PKS 0447-439. Our results indicate that the spectral energy distribution (SED) of PKS 0447-439 can be reproduced well by the model. In particular, the GeV-TeV emission is produced by the synchrotron radiation of relativistic protons. The physically plausible solutions require the magnetic strength 10 G≲ B ≲ 100 G. We found that the observed spectrum of PKS 0447-439 can be reproduced well by the model whether z = 0.16 or z = 0.2, and the acceptable upper limit of redshift is z=0.343.

Design of a synchrotron radiation detector for the test beam lines at the Superconducting Super Collider Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hutton, R.D.

1994-01-01

As part of the particle- and momentum-tagging instrumentation required for the test beam lines of the Superconducting Super Collider (SSC), the synchrotron radiation detector (SRD) was designed to provide electron tagging at momentum above 75 GeV. In a parallel effort to the three test beam lines at the SSC, schedule demands required testing and calibration operations to be initiated at Fermilab. Synchrotron radiation detectors also were to be installed in the NM and MW beam lines at Femilab before the test beam lines at the SSC would become operational. The SRD is the last instrument in a series of threemore » used in the SSC test beam fines. It follows a 20-m drift section of beam tube downstream of the last silicon strip detector. A bending dipole just in of the last silicon strip detector produces the synchrotron radiation that is detected in a 50-mm-square cross section NaI crystal. A secondary scintillator made of Bicron BC-400 plastic is used to discriminate whether it is synchrotron radiation or a stray particle that causes the triggering of the NaI crystal`s photo multiplier tube (PMT).« less

Non-destructive evaluation of teeth restored with different composite resins using synchrotron based micro-imaging.

PubMed

Fatima, A; Kulkarni, V K; Banda, N R; Agrawal, A K; Singh, B; Sarkar, P S; Tripathi, S; Shripathi, T; Kashyap, Y; Sinha, A

2016-01-01

Application of high resolution synchrotron micro-imaging in microdefects studies of restored dental samples. The purpose of this study was to identify and compare the defects in restorations done by two different resin systems on teeth samples using synchrotron based micro-imaging techniques namely Phase Contrast Imaging (PCI) and micro-computed tomography (MCT). With this aim acquired image quality was also compared with routinely used RVG (Radiovisiograph). Crowns of human teeth samples were fractured mechanically involving only enamel and dentin, without exposure of pulp chamber and were divided into two groups depending on the restorative composite materials used. Group A samples were restored using a submicron Hybrid composite material and Group B samples were restored using a Nano-Hybrid restorative composite material. Synchrotron based PCI and MCT was performed with the aim of visualization of tooth structure, composite resin and their interface. The quantitative and qualitative comparison of phase contrast and absorption contrast images along with MCT on the restored teeth samples shows comparatively large number of voids in Group A samples. Quality assessment of dental restorations using synchrotron based micro-imaging suggests Nano-Hybrid resin restorations (Group B) are better than Group A.

Multiscale tomographic analysis of heterogeneous cast Al-Si-X alloys.

PubMed

Asghar, Z; Requena, G; Sket, F

2015-07-01

The three-dimensional microstructure of cast AlSi12Ni and AlSi10Cu5Ni2 alloys is investigated by laboratory X-ray computed tomography, synchrotron X-ray computed microtomography, light optical tomography and synchrotron X-ray computed microtomography with submicrometre resolution. The results obtained with each technique are correlated with the size of the scanned volumes and resolved microstructural features. Laboratory X-ray computed tomography is sufficient to resolve highly absorbing aluminides but eutectic and primary Si remain unrevealed. Synchrotron X-ray computed microtomography at ID15/ESRF gives better spatial resolution and reveals primary Si in addition to aluminides. Synchrotron X-ray computed microtomography at ID19/ESRF reveals all the phases ≥ ∼1 μm in volumes about 80 times smaller than laboratory X-ray computed tomography. The volumes investigated by light optical tomography and submicrometre synchrotron X-ray computed microtomography are much smaller than laboratory X-ray computed tomography but both techniques provide local chemical information on the types of aluminides. The complementary techniques applied enable a full three-dimensional characterization of the microstructure of the alloys at length scales ranging over six orders of magnitude. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

European research platform IPANEMA at the SOLEIL synchrotron for ancient and historical materials.

PubMed

Bertrand, L; Languille, M-A; Cohen, S X; Robinet, L; Gervais, C; Leroy, S; Bernard, D; Le Pennec, E; Josse, W; Doucet, J; Schöder, S

2011-09-01

IPANEMA, a research platform devoted to ancient and historical materials (archaeology, cultural heritage, palaeontology and past environments), is currently being set up at the synchrotron facility SOLEIL (Saint-Aubin, France; SOLEIL opened to users in January 2008). The new platform is open to French, European and international users. The activities of the platform are centred on two main fields: increased support to synchrotron projects on ancient materials and methodological research. The IPANEMA team currently occupies temporary premises at SOLEIL, but the platform comprises construction of a new building that will comply with conservation and environmental standards and of a hard X-ray imaging beamline today in its conceptual design phase, named PUMA. Since 2008, the team has supported synchrotron works at SOLEIL and at European synchrotron facilities on a range of topics including pigment degradation in paintings, composition of musical instrument varnishes, and provenancing of medieval archaeological ferrous artefacts. Once the platform is fully operational, user support will primarily take place within medium-term research projects for `hosted' scientists, PhDs and post-docs. IPANEMA methodological research is focused on advanced two-dimensional/three-dimensional imaging and spectroscopy and statistical image analysis, both optimized for ancient materials.

National Synchrotron Light Source

ScienceCinema

None

2017-12-09

A tour of Brookhaven's National Synchrotron Light Source (NSLS). The NSLS is one of the world's most widely used scientific research facilities, hosting more than 2,500 guest researchers each year. The NSLS provides intense beams of infrared, ultraviole

A Model Describing Stable Coherent Synchrotron Radiation in Storage Rings

NASA Astrophysics Data System (ADS)

Sannibale, F.; Byrd, J. M.; Loftsdóttir, Á.; Venturini, M.; Abo-Bakr, M.; Feikes, J.; Holldack, K.; Kuske, P.; Wüstefeld, G.; Hübers, H.-W.; Warnock, R.

2004-08-01

We present a model describing high power stable broadband coherent synchrotron radiation (CSR) in the terahertz frequency region in an electron storage ring. The model includes distortion of bunch shape from the synchrotron radiation (SR), which enhances higher frequency coherent emission, and limits to stable emission due to an instability excited by the SR wakefield. It gives a quantitative explanation of several features of the recent observations of CSR at the BESSYII storage ring. We also use this model to optimize the performance of a source for stable CSR emission.

Focusing of white synchrotron radiation using large-acceptance cylindrical refractive lenses made of single – crystal diamond

DOE Office of Scientific and Technical Information (OSTI.GOV)

Polikarpov, M., E-mail: polikarpov.maxim@mail.ru; Snigireva, I.; Snigirev, A.

2016-07-27

Large-aperture cylindrical refractive lenses were manufactured by laser cutting of single-crystal diamond. Five linear single lenses with apertures of 1 mm and the depth of the structure of 1.2 mm were fabricated and tested at the ESRF ID06 beamline performing the focusing of white-beam synchrotron radiation. Uniform linear focus was stable during hours of exposure, representing such lenses as pre-focusing and collimating devices suitable for the front-end sections of today synchrotron radiation sources.

Updating the Synchrotron Radiation Monitor at TLS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuo, C. H.; Hsu, S. Y.; Wang, C. J.

2007-01-19

The synchrotron radiation monitor provides useful information to support routine operation and physics experiments using the beam. Precisely knowing the profile of the beam helps to improve machine performance. The synchrotron radiation monitor at the Taiwan Light Source (TLS) was recently upgraded. The optics and modeling were improved to increase the accuracy of measurement in the small beam size. A high-performance IEEE-1394 digital CCD camera was used to improve the quality of images and extend the dynamic range of measurement. The image analysis is also improved. This report summarizes status and results.

High speed systems for time-resolved experiments with synchrotron radiation

NASA Astrophysics Data System (ADS)

Koziol, Anna; Maj, Piotr

2018-02-01

The UFXC32k is a single photon counting hybrid pixel detector with 75 μm pixel pitch. It was designed to cope with high X-ray intensities and therefore it is a very good candiate for synchrotron applications. In order to use this detector in an application, a dedicated setup must be designed and built allowing proper operation of the detector within the experiment. The paper presents two setups built for the purpose of Pump-Probe-Probe experiments at the Synchrotron SOLEIL and XPCS experiments at the APS.

Applications of synchrotron radiation to materials science: Diffraction imaging (topography) and microradiography

NASA Technical Reports Server (NTRS)

Kuriyama, Masao

1988-01-01

Synchrotron radiation sources are now available throughout the world. The use of hard X-ray radiation from these sources for materials science is described with emphasis on diffraction imaging for material characterization. With the availability of synchrotron radiation, real-time in situ measurements of dynamic microstructural phenomena have been started. This is a new area where traditional application of X-rays has been superseded. Examples are chosen from limited areas and are by no means exhaustive. The new emerging information will, no doubt, have great impact on materials science and engineering.

Relativistic thermal plasmas - Effects of magnetic fields

NASA Technical Reports Server (NTRS)

Araki, S.; Lightman, A. P.

1983-01-01

Processes and equilibria in finite, relativistic, thermal plasmas are investigated, taking into account electron-positron creation and annihilation, photon production by internal processes, and photon production by a magnetic field. Inclusion of the latter extends previous work on such plasmas. The basic relations for thermal, Comptonized synchrotron emission are analyzed, including emission and absorption without Comptonization, Comptonized thermal synchrotron emission, and the Comptonized synchrotron and bremsstrahlung luminosities. Pair equilibria are calculated, including approximations and dimensionless parameters, the pair balance equation, maximum temperatures and field strengths, and individual models and cooling curves.

Animals In Synchrotrons: Overcoming Challenges For High-Resolution, Live, Small-Animal Imaging

NASA Astrophysics Data System (ADS)

Donnelley, Martin; Parsons, David; Morgan, Kaye; Siu, Karen

2010-07-01

Physiological studies in small animals can be complicated, but the complexity is increased dramatically when performing live-animal synchrotron X-ray imaging studies. Our group has extensive experience in high-resolution live-animal imaging at the Japanese SPring-8 synchrotron, primarily examining airways in two-dimensions. These experiments normally image an area of 1.8 mm×1.2 mm at a pixel resolution of 0.45 μm and are performed with live, intact, anaesthetized mice. There are unique challenges in this experimental setting. Importantly, experiments must be performed in an isolated imaging hutch not specifically designed for small-animal imaging. This requires equipment adapted to remotely monitor animals, maintain their anesthesia, and deliver test substances while collecting images. The horizontal synchrotron X-ray beam has a fixed location and orientation that limits experimental flexibility. The extremely high resolution makes locating anatomical regions-of-interest slow and can result in a high radiation dose, and at this level of magnification small animal movements produce motion-artifacts that can render acquired images unusable. Here we describe our experimental techniques and how we have overcome several challenges involved in performing live mouse synchrotron imaging. Experiments have tested different mouse strains, with hairless strains minimizing overlying skin and hair artifacts. Different anesthetics have also be trialed due to the limited choices available at SPring-8. Tracheal-intubation methods have been refined and controlled-ventilation is now possible using a specialized small-animal ventilator. With appropriate animal restraint and respiratory-gating, motion-artifacts have been minimized. The animal orientation (supine vs. head-high) also appears to affect animal physiology, and can alter image quality. Our techniques and image quality at SPring-8 have dramatically improved and in the near future we plan to translate this experience to the Imaging and Medical Beamline at the Australian Synchrotron. Overcoming these challenges has permitted increasingly sophisticated imaging of animals with synchrotron X-rays, and we expect a bright future for these techniques.

Distributions of Gamma-Ray Bursts and Blazars in the L p-E p-Plane and Possible Implications for their Radiation Physics

NASA Astrophysics Data System (ADS)

Lyu, Fen; Liang, En-Wei; Liang, Yun-Feng; Wu, Xue-Feng; Zhang, Jin; Sun, Xiao-Na; Lu, Rui-Jing; Zhang, Bing

2014-09-01

We present a spectral analysis for a sample of redshift-known gamma-ray bursts (GRBs) observed with Fermi/GBM. Together with the results derived from our systematical spectral energy distribution modeling with the leptonic models for a Fermi/LAT blazar sample, we compare the distributions of the GRBs and the blazars by plotting the synchrotron peak luminosity (L s) and the corresponding peak photon energy E s of blazars in the L p-E p-plane of GRBs, where L p and E p are the peak luminosity and peak photon energy of the GRB time-integrated νf ν spectrum, respectively. The GRBs are in the high-L p, high-E p corner of the plane and a tight L p-E p relation is found, i.e., L_p\\propto E_p2.13^{+0.54-0.46}. Both flat spectrum radio quasars (FSRQs) and low-synchrotron peaking BL Lac objects (LBLs) are clustered in the low-E p, low-L p corner. Intermediate- and high-synchrotron peaking BL Lac objects (IBLs and HBLs) have E s ~ 2 × 10-3-102 keV and L s ~ 1044-1047 erg s-1, but no dependence of L s on E s is found. We show that the tight Lp -Ep relation of GRBs is potentially explained with the synchrotron radiation of fast-cooling electrons in a highly magnetized ejecta, and the weak anti-correlation of L s-E s for FSRQs and LBLs may be attributed to synchrotron radiation of slow-cooling electrons in a moderately magnetized ejecta. The distributions of IBLs and HBLs in the L p-E p-plane may be interpreted with synchrotron radiation of fast-cooling electrons in a matter-dominated ejecta. These results may present a unified picture for the radiation physics of relativistic jets in GRBs and blazars within the framework of the leptonic synchrotron radiation models.

High-Resolution Synchrotron Radiation Imaging of Trace Metal Elemental Concentrations in Porites Coral

NASA Astrophysics Data System (ADS)

Cirino, M.; Dunbar, R. B.; Tangri, N.; Mehta, A.

2014-12-01

We investigated the use of synchrotron radiation for elemental imaging within the skeleton of a Porites coral from American Samoa to explore the fine-scale structure of strontium to calcium (Sr/Ca) variability. The use of a synchrotron for coral paleoclimate analysis is relatively new. The method provides a high resolution, two-dimensional elemental map of a coral surface. The aragonitic skeleton of Porites sp. colonies has been widely used for paleoclimate reconstruction as the oxygen isotope ratio (δ18O) signal varies with both sea surface temperature (SST) and sea surface salinity (SSS). Sr/Ca has been used in previous studies in conjunction with δ18O to deconvolve SST from SSS, as Sr/Ca in the coral skeleton varies with SST, but not SSS. However, recent studies suggest that in some cases Sr/Ca variability in coral does not reliably reflect changes in SST. We sought to address this puzzle by investigating Sr/Ca variability in Porites corals at a very fine spatial scale while also demonstrating the suitability of the synchrotron as a coral analysis tool. We also considered Sr/Ca variability as it pertains to the coral's structural elements. The Stanford Linear Accelerator Center synchrotron station generates collimated x-rays in the energy range of 4500-45000 eV with beam diameters as small as 20 μm. Synchrotron imaging allows faster and higher-resolution Sr/Ca analysis than does inductively coupled plasma mass spectrometry (ICP-MS). It also is capable of mapping spatial distributions of many elements, which aids in the development of a multiproxy approach to paleoclimate reconstruction. Imaging and analysis of the Porites coral using synchrotron radiation revealed an intricate sub-seasonal Sr/Ca signal, possibly correlating to a sub-monthly resolution. This signal, which seems unrelated to SST, dominates the annual signal.

Animals In Synchrotrons: Overcoming Challenges For High-Resolution, Live, Small-Animal Imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Donnelley, Martin; Parsons, David; Women's and Children's Health Research Institute, Adelaide, South Australia

Physiological studies in small animals can be complicated, but the complexity is increased dramatically when performing live-animal synchrotron X-ray imaging studies. Our group has extensive experience in high-resolution live-animal imaging at the Japanese SPring-8 synchrotron, primarily examining airways in two-dimensions. These experiments normally image an area of 1.8 mmx1.2 mm at a pixel resolution of 0.45 {mu}m and are performed with live, intact, anaesthetized mice.There are unique challenges in this experimental setting. Importantly, experiments must be performed in an isolated imaging hutch not specifically designed for small-animal imaging. This requires equipment adapted to remotely monitor animals, maintain their anesthesia, andmore » deliver test substances while collecting images. The horizontal synchrotron X-ray beam has a fixed location and orientation that limits experimental flexibility. The extremely high resolution makes locating anatomical regions-of-interest slow and can result in a high radiation dose, and at this level of magnification small animal movements produce motion-artifacts that can render acquired images unusable. Here we describe our experimental techniques and how we have overcome several challenges involved in performing live mouse synchrotron imaging.Experiments have tested different mouse strains, with hairless strains minimizing overlying skin and hair artifacts. Different anesthetics have also be trialed due to the limited choices available at SPring-8. Tracheal-intubation methods have been refined and controlled-ventilation is now possible using a specialized small-animal ventilator. With appropriate animal restraint and respiratory-gating, motion-artifacts have been minimized. The animal orientation (supine vs. head-high) also appears to affect animal physiology, and can alter image quality. Our techniques and image quality at SPring-8 have dramatically improved and in the near future we plan to translate this experience to the Imaging and Medical Beamline at the Australian Synchrotron.Overcoming these challenges has permitted increasingly sophisticated imaging of animals with synchrotron X-rays, and we expect a bright future for these techniques.« less

On the synchrotron emission in kinetic simulations of runaway electrons in magnetic confinement fusion plasmas

NASA Astrophysics Data System (ADS)

Carbajal, L.; del-Castillo-Negrete, D.

2017-12-01

Developing avoidance or mitigation strategies of runaway electrons (REs) in magnetic confinement fusion (MCF) plasmas is of crucial importance for the safe operation of ITER. In order to develop these strategies, an accurate diagnostic capability that allows good estimates of the RE distribution function in these plasmas is needed. Synchrotron radiation (SR) of RE in MCF, besides of being one of the main damping mechanisms for RE in the high energy relativistic regime, is routinely used in current MCF experiments to infer the parameters of RE energy and pitch angle distribution functions. In the present paper we address the long standing question about what are the relationships between different REs distribution functions and their corresponding synchrotron emission simultaneously including: full-orbit effects, information of the spectral and angular distribution of SR of each electron, and basic geometric optics of a camera. We study the spatial distribution of the SR on the poloidal plane, and the statistical properties of the expected value of the synchrotron spectra of REs. We observe a strong dependence of the synchrotron emission measured by the camera on the pitch angle distribution of runaways, namely we find that crescent shapes of the spatial distribution of the SR as measured by the camera relate to RE distributions with small pitch angles, while ellipse shapes relate to distributions of runaways with larger the pitch angles. A weak dependence of the synchrotron emission measured by the camera with the RE energy, value of the q-profile at the edge, and the chosen range of wavelengths is observed. Furthermore, we find that oversimplifying the angular dependence of the SR changes the shape of the synchrotron spectra, and overestimates its amplitude by approximately 20 times for avalanching runaways and by approximately 60 times for mono-energetic distributions of runaways1.

Translation of Atherosclerotic Plaque Phase-Contrast CT Imaging from Synchrotron Radiation to a Conventional Lab-Based X-Ray Source

PubMed Central

Saam, Tobias; Herzen, Julia; Hetterich, Holger; Fill, Sandra; Willner, Marian; Stockmar, Marco; Achterhold, Klaus; Zanette, Irene; Weitkamp, Timm; Schüller, Ulrich; Auweter, Sigrid; Adam-Neumair, Silvia; Nikolaou, Konstantin; Reiser, Maximilian F.; Pfeiffer, Franz; Bamberg, Fabian

2013-01-01

Objectives Phase-contrast imaging is a novel X-ray based technique that provides enhanced soft tissue contrast. The aim of this study was to evaluate the feasibility of visualizing human carotid arteries by grating-based phase-contrast tomography (PC-CT) at two different experimental set-ups: (i) applying synchrotron radiation and (ii) using a conventional X-ray tube. Materials and Methods Five ex-vivo carotid artery specimens were examined with PC-CT either at the European Synchrotron Radiation Facility using a monochromatic X-ray beam (2 specimens; 23 keV; pixel size 5.4 µm), or at a laboratory set-up on a conventional X-ray tube (3 specimens; 35-40 kVp; 70 mA; pixel size 100 µm). Tomographic images were reconstructed and compared to histopathology. Two independent readers determined vessel dimensions and one reader determined signal-to-noise ratios (SNR) between PC-CT and absorption images. Results In total, 51 sections were included in the analysis. Images from both set-ups provided sufficient contrast to differentiate individual vessel layers. All PCI-based measurements strongly predicted but significantly overestimated lumen, intima and vessel wall area for both the synchrotron and the laboratory-based measurements as compared with histology (all p<0.001 with slope >0.53 per mm2, 95%-CI: 0.35 to 0.70). Although synchrotron-based images were characterized by higher SNRs than laboratory-based images; both PC-CT set-ups had superior SNRs compared to corresponding conventional absorption-based images (p<0.001). Inter-reader reproducibility was excellent (ICCs >0.98 and >0.84 for synchrotron and for laboratory-based measurements; respectively). Conclusion Experimental PC-CT of carotid specimens is feasible with both synchrotron and conventional X-ray sources, producing high-resolution images suitable for vessel characterization and atherosclerosis research. PMID:24039969

Fast-cycling superconducting synchrotrons and possible path to the future of US experimental high-energy particle physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Piekarz, Henryk; /Fermilab

The authors outline primary physics motivation, present proposed new arrangement for Fermilab accelerator complex, and then discuss possible long-range application of fast-cycling superconducting synchrotrons at Fermilab.

Picosecond x-ray diagnostics for third and fourth generation synchrotron sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

DeCamp, Matthew

2016-03-30

In the DOE-EPSCoR State/National Laboratory partnership grant ``Picosecond x-ray diagnostics for third and fourth generation synchrotron sources'' Dr. DeCamp set forth a partnership between the University of Delaware and Argonne National Laboratory. This proposal aimed to design and implement a series of experiments utilizing, or improving upon, existing time-domain hard x-ray spectroscopies at a third generation synchrotron source. Specifically, the PI put forth three experimental projects to be explored in the grant cycle: 1) implementing a picosecond ``x-ray Bragg switch'' using a laser excited nano-structured metallic film, 2) designing a robust x-ray optical delay stage for x-ray pump-probe studies atmore » a hard x-ray synchrotron source, and 3) building/installing a laser based x-ray source at the Advanced Photon Source for two-color x-ray pump-probe studies.« less

The angular power spectrum measurement of the Galactic synchrotron emission using the TGSS survey

NASA Astrophysics Data System (ADS)

Choudhuri, Samir; Bharadwaj, Somnath; Ali, Sk. Saiyad; Roy, Nirupam; Intema, H. T.; Ghosh, Abhik

2018-05-01

Characterizing the diffuse Galactic synchrotron emission (DGSE) at arcminute angular scales is needed to remove this foregrounds in cosmological 21-cm measurements. Here, we present the angular power spectrum (Cl) measurement of the diffuse Galactic synchrotron emission using two fields observed by the TIFR GMRT Sky Survey (TGSS). We apply 2D Tapered Gridded Estimator (TGE) to estimate the Cl from the visibilities. We find that the residual data after subtracting the point sources is likely dominated by the diffuse Galactic synchrotron radiation across the angular multipole range 240 <= l <~ 500. We fit a power law to the measured Cl over this l range. We find that the slopes in both fields are consistent with earlier measurements. For the second field, however, we interpret the measured Cl as an upper limit for the DGSE as there is an indication of a significant residual point source contribution.

In vitro synchrotron-based radiography of micro-gap formation at the implant-abutment interface of two-piece dental implants.

PubMed

Rack, A; Rack, T; Stiller, M; Riesemeier, H; Zabler, S; Nelson, K

2010-03-01

Micro-gap formation at the implant-abutment interface of two-piece dental implants was investigated in vitro using high-resolution radiography in combination with hard X-ray synchrotron radiation. Images were taken with the specimen under different mechanical loads of up to 100 N. The aim of this investigation was to prove the existence of micro-gaps for implants with conical connections as well as to study the mechanical behavior of the mating zone of conical implants during loading. Synchrotron-based radiography in comparison with classical laboratory radiography yields high spatial resolution in combination with high contrast even when exploiting micro-sized features in highly attenuating objects. The first illustration of a micro-gap which was previously indistinguishable by laboratory methods underlines that the complex micro-mechanical behavior of implants requires further in vitro investigations where synchrotron-based micro-imaging is one of the prerequisites.

Fluorescence dynamics of biological systems using synchrotron radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gratton, E.; Mantulin, W.W.; Weber, G.

1996-09-01

A beamline for time-resolved fluorescence spectroscopy of biological systems is under construction at the Synchrotron Radiation Center. The fluorometer, operating in the frequency domain, will take advantage of the time structure of the synchrotron radiation light pulses to determine fluorescence lifetimes. Using frequency-domain techniques, the instrument can achieve an ultimate time resolution on the order of picoseconds. Preliminary experiments have shown that reducing the intensity of one of the fifteen electron bunches in the storage ring allows measurement of harmonic frequencies equivalent to the single-bunch mode. This mode of operation of the synchrotron significantly extends the range of lifetimes thatmore » can be measured. The wavelength range (encompassing the visible and ultraviolet), the range of measurable lifetimes, and the stability and reproducibility of the storage ring pulses should make this beamline a versatile tool for the investigation of the complex fluorescence decay of biological systems. {copyright} {ital 1996 American Institute of Physics.}« less

Synchrotron X-ray microfluorescence measurement of metal distributions in Phragmites australis root system in the Yangtze River intertidal zone

DOE PAGES

Feng, Huan; Zhang, Weiguo; Qian, Yu; ...

2016-06-15

This paper investigates the distributions of Br, Ca, Cl, Cr, Cu, K, Fe, Mn, Pb, Ti, V and Zn in Phragmites australis root system and the function of Fe nanoparticles in scavenging metals in the root epidermis using synchrotron X-ray microfluorescence, synchrotron transmission X-ray microscope measurement and synchrotron X-ray absorption near-edge structure techniques. The purpose of this study is to understand the mobility of metals in wetland plant root systems after their uptake from rhizosphere soils. Phragmites australis samples were collected in the Yangtze River intertidal zone in July 2013. The results indicate that Fe nanoparticles are present in themore » root epidermis and that other metals correlate significantly with Fe, suggesting that Fe nanoparticles play an important role in metal scavenging in the epidermis.« less

Synchrotron X-ray microfluorescence measurement of metal distributions in Phragmites australis root system in the Yangtze River intertidal zone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feng, Huan; Zhang, Weiguo; Qian, Yu

This paper investigates the distributions of Br, Ca, Cl, Cr, Cu, K, Fe, Mn, Pb, Ti, V and Zn in Phragmites australis root system and the function of Fe nanoparticles in scavenging metals in the root epidermis using synchrotron X-ray microfluorescence, synchrotron transmission X-ray microscope measurement and synchrotron X-ray absorption near-edge structure techniques. The purpose of this study is to understand the mobility of metals in wetland plant root systems after their uptake from rhizosphere soils. Phragmites australis samples were collected in the Yangtze River intertidal zone in July 2013. The results indicate that Fe nanoparticles are present in themore » root epidermis and that other metals correlate significantly with Fe, suggesting that Fe nanoparticles play an important role in metal scavenging in the epidermis.« less

Synchrotron radiation from a runaway electron distribution in tokamaks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stahl, A.; Fülöp, T.; Landreman, M.

2013-09-15

The synchrotron radiation emitted by runaway electrons in a fusion plasma provides information regarding the particle momenta and pitch-angles of the runaway electron population through the strong dependence of the synchrotron spectrum on these parameters. Information about the runaway density and its spatial distribution, as well as the time evolution of the above quantities, can also be deduced. In this paper, we present the synchrotron radiation spectra for typical avalanching runaway electron distributions. Spectra obtained for a distribution of electrons are compared with the emission of mono-energetic electrons with a prescribed pitch-angle. We also examine the effects of magnetic fieldmore » curvature and analyse the sensitivity of the resulting spectrum to perturbations to the runaway distribution. The implications for the deduced runaway electron parameters are discussed. We compare our calculations to experimental data from DIII-D and estimate the maximum observed runaway energy.« less

Rising dough and baking bread at the Australian synchrotron

NASA Astrophysics Data System (ADS)

Mayo, S. C.; McCann, T.; Day, L.; Favaro, J.; Tuhumury, H.; Thompson, D.; Maksimenko, A.

2016-01-01

Wheat protein quality and the amount of common salt added in dough formulation can have a significant effect on the microstructure and loaf volume of bread. High-speed synchrotron micro-CT provides an ideal tool for observing the three dimensional structure of bread dough in situ during proving (rising) and baking. In this work, the synchrotron micro-CT technique was used to observe the structure and time evolution of doughs made from high and low protein flour and three different salt additives. These experiments showed that, as expected, high protein flour produces a higher volume loaf compared to low protein flour regardless of salt additives. Furthermore the results show that KCl in particular has a very negative effect on dough properties resulting in much reduced porosity. The hundreds of datasets produced and analysed during this experiment also provided a valuable test case for handling large quantities of data using tools on the Australian Synchrotron's MASSIVE cluster.

Invited Article: Refined analysis of synchrotron radiation for NIST's SURF III facility

NASA Astrophysics Data System (ADS)

Shirley, Eric L.; Furst, Mitchell; Arp, Uwe

2018-04-01

We have developed a new method for the exact calculation of synchrotron radiation for the National Institute of Standards and Technology Synchrotron Ultraviolet Radiation Facility, SURF III. Instead of using the Schwinger formula, which is only an approximation, we develop formulae based on Graf's addition theorem for Bessel functions and accurate asymptotic expansions for Hankel functions and Bessel functions. By measuring the radiation intensity profile at two distances from the storage ring, we also confirm an apparent vertical emittance that is consistent with the vertical betatron oscillations that are intentionally introduced to extend beam lifetime by spreading the electron beam spatially. Finally, we determine how much diffraction by beamline apertures enhances the spectral irradiance at an integrating sphere entrance port at the end station. This should eliminate small but treatable components of the uncertainty budget that one should consider when using SURF III or similar synchrotrons as standard, calculable sources of ultraviolet and other radiation.

Double Compton and Cyclo-Synchrotron in Super-Eddington Discs, Magnetized Coronae, and Jets

NASA Astrophysics Data System (ADS)

McKinney, Jonathan C.; Chluba, Jens; Wielgus, Maciek; Narayan, Ramesh; Sadowski, Aleksander

2017-05-01

Black hole accretion discs accreting near the Eddington rate are dominated by bremsstrahlung cooling, but above the Eddington rate, the double Compton process can dominate in radiation-dominated regions, while the cyclo-synchrotron can dominate in strongly magnetized regions like a corona or a jet. We present an extension to the general relativistic radiation magnetohydrodynamic code harmrad to account for emission and absorption by thermal cyclo-synchrotron, double Compton, bremsstrahlung, low-temperature opal opacities, as well as Thomson and Compton scattering. The harmrad code and associated analysis and visualization codes have been made open-source and are publicly available at the github repository website. We approximate the radiation field as a Bose-Einstein distribution and evolve it using the radiation number-energy-momentum conservation equations in order to track photon hardening. We perform various simulations to study how these extensions affect the radiative properties of magnetically arrested discs accreting at Eddington to super-Eddington rates. We find that double Compton dominates bremsstrahlung in the disc within a radius of r ˜ 15rg (gravitational radii) at hundred times the Eddington accretion rate, and within smaller radii at lower accretion rates. Double Compton and cyclo-synchrotron regulate radiation and gas temperatures in the corona, while cyclo-synchrotron regulates temperatures in the jet. Interestingly, as the accretion rate drops to Eddington, an optically thin corona develops whose gas temperature of T ˜ 109K is ˜100 times higher than the disc's blackbody temperature. Our results show the importance of double Compton and synchrotron in super-Eddington discs, magnetized coronae and jets.

Synchrotron Self-Compton Emission from the Crab and Other Pulsars

NASA Astrophysics Data System (ADS)

Harding, Alice K.; Kalapotharakos, Constantinos

2015-09-01

Results of a simulation of synchrotron self-Compton (SSC) emission from a rotation-powered pulsar are presented. The radiating particles are assumed to be both accelerated primary electrons and a spectrum of electron-positron pairs produced in cascades near the polar cap. They follow trajectories in a slot gap using 3D force-free magnetic field geometry, gaining pitch angles through resonant cyclotron absorption of radio photons, radiating and scattering synchrotron emission at high altitudes out to and beyond the light cylinder. Full angular dependence of the synchrotron photon density is simulated in the scattering and all processes are treated in the inertial observer frame. Spectra for the Crab and Vela pulsars as well as two energetic millisecond pulsars, B1821-24 and B1937+21, are simulated using this model. The simulation of the Crab pulsar radiation can reproduce both the flux level and the shape of the observed optical to hard X-ray emission assuming a pair multiplicity of {M}+=3× {10}5, as well as the very-high-energy emission above 50 GeV detected by MAGIC and VERITAS, with both the synchrotron and SSC components reflecting the shape of the pair spectrum. Simulations of Vela, B1821-24, and B1937+21, for {M}+ up to 105, do not produce pair SSC emission that is detectable by current telescopes, indicating that only Crab-like pulsars produce significant SSC components. The pair synchrotron emission matches the observed X-ray spectrum of the millisecond pulsars, and the predicted peak of this emission at 1-10 MeV would be detectable with planned Compton telescopes.

Synchrotron Radiation II.

ERIC Educational Resources Information Center

MOSAIC, 1978

1978-01-01

Synchrotron radiation is a unique form of radiation that spans the electro-magnetic spectrum from X-rays through the ultraviolet and visible into the infrared. Tunable monochromators enable scientists to select a narrow band of wavelengths at any point in the spectrum. (Author/BB)

National Synchrotron Light Source II

ScienceCinema

Steve Dierker

2017-12-09

The National Synchrotron Light Source II (NSLS-II) at the U.S. Department of Energy's Brookhaven National Laboratory is a proposed new state-of-the-art medium energy storage ring designed to deliver world-leading brightness and flux with top-off operation

Report of the workshop on transferring X-ray Lithography Synchrotron (XLS) technology to industry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marcuse, W.

1987-01-01

This paper reports on plans to develop an x-ray synchrotron for use in lithography. The primary concern of the present paper is technology transfer from national laboratories to private industry. (JDH)

Observation of Multi-bunch Interference with Coherent Synchrotron Radiation

NASA Astrophysics Data System (ADS)

Billinghurst, B. E.; May, T.; Bergstrom, J.; DeJong, M.; Dallin, L.

2010-02-01

The observation of Multi-bunch interference with coherent synchrotron radiation at the Canadian Light Source is discussed along with the possibility that some of the spectral features are driven by the radiation impedance of the vacuum chamber.

a Study of the Synchrotron Laue Method for Quantitative Crystal Structure Analysis.

NASA Astrophysics Data System (ADS)

Gomez de Anderez, Dora M.

1990-01-01

Available from UMI in association with The British Library. Quantitative crystal structure analyses have been carried out on small molecule crystals using synchrotron radiation and the Laue method. A variety of single crystal structure determinations and associated refinements are used and compared with the monochromatic analyses. The new molecular structure of 7-amino-5-bromo -4-methyl-2-oxo-1,2,3,4-tetrahidro-1, 6 -naphthyridine-8-carbonitrile (C_{10 }H_9ON_4 Br.H_2O) has been determined, first using monochromatic Mo Kalpha radiation and a four-circle diffractometer, then using synchrotron Laue diffraction photography. The structure refinements showed a R-factor of 4.97 and 14.0% for the Mo Kalpha and Laue data respectively. The molecular structure of (S)-2-chloro-2-fluoro-N-((S)-1-phenylethyl) ethanamide, (C_{10}H _{11}ClFNO), has been determined using the same crystal throughout for X-ray monochromatic analyses (Mo Kalpha and Cu K alpha) followed by synchrotron Laue data collection. The Laue and monochromatic data compare favourably. The R -factors (on F) were 6.23, 6.45 and 8.19% for the Mo K alpha, Cu Kalpha and Laue data sets respectively. The molecular structure of 3-(5-hydroxy-3-methyl-1-phenylpyrazol-4-yl)-1,3-diphenyl -prop- 2-en-1-one, (C_{25 }H_{20}N _2O_2) has been determined using the synchrotron Laue method. The results compare very well with Mo Kalpha monochromatic data. The R-factors (on F) were 4.60 and 5.29% for Mo Kalpha and Laue analysis respectively. The Laue method is assessed in locating the 20 hydrogen atoms in this structure. The structure analysis of the benzil compound ((C_6H_5 O.CO_2)) is carried out using the synchrotron Laue method firstly at room temperature and secondly at low temperature -114 ^circC. The structure shows an R-factor (on F) of 13.06% and 6.85% for each data set respectively. The synchrotron Laue method was used to collect data for ergocalciferol (Vitamin D_2). The same crystal was also used to record oscillation data with the synchrotron radiation monochromatic beam. A new molecular structure of (Dinitrato-(N,N ^'-dimethylethylene-diamine)copper(II)) has been determined using Mo Kalpha radiation on a four circle diffractometer. The refinement resulted in an R-factor (on F) of 4.06%.

A Study of the Synchrotron Laue Method for Quantitative Crystal Structure Analysis

NASA Astrophysics Data System (ADS)

Gomez de Anderez, Dora M.

1990-01-01

Quantitative crystal structure analyses have been carried out on small molecule crystals using synchrotron radiation and the Laue method. A variety of single crystal structure determinations and associated refinements are used and compared with the monochromatic analyses. The new molecular structure of 7-amino-5-bromo -4-methyl-2-oxo-1,2,3,4 -tetrahidro-1,6 -naphthyridine-8-carbonitrile (C_{10 }H_9ON_4 BrcdotH_2O) has been determined, first using monochromatic Mo K alpha radiation and a four-circle diffractometer, then using synchrotron Laue diffraction photography. The structure refinements showed an R-factor of 4.97 and 14.0% for the Mo Kalpha and Laue data respectively. The molecular structure of (S)-2-chloro-2-fluoro-N-((S)-1-phenylethyl) ethanamide, (C_{10}H _{11}ClFNO), has been determined using the same crystal throughout for X-ray monochromatic analyses (Mo Kalpha and Cu K alpha) followed by synchrotron Laue data collection. The Laue and monochromatic data compare favourably. The R -factors (on F) were 6.23, 6.45 and 8.19% for the Mo K alpha, Cu Kalpha and Laue data sets respectively. The molecular structure of 3-(5-hydroxy-3-methyl-1-phenylpyrazol-4-yl)-1,3-diphenyl -prop-2-en-1-one, (C_{25}H _{20}N_2 O_2) has been determined using the synchrotron Laue method. The results compare very well with Mo Kalpha monochromatic data. The R-factors (on F) were 4.60 and 5.29% for Mo Kalpha and Laue analyses respectively. The Laue method is assessed in locating the 20 hydrogen atoms in this structure. The structure analyses of the benzil compound ((C_6H_5 OcdotCO_2)) is carried out using the synchrotron Laue method firstly at room temperature and secondly at low temperature. The structure shows an R-factor (on F) of 13.06% and 6.85% for each data set respectively. The synchrotron Laue method was used to collect data for ergocalciferol (Vitamin D_2). The same crystal was also used to record oscillation data with the synchrotron radiation monochromatic beam. A new molecular structure of (Dinitrato-(N,N ^'-dimethylethylene-diamine)copper(II)) has been determined using Mo Kalpha radiation on a four circle diffractometer. The refinement resulted in an R-factor (on F) of 4.06%.

Finite elements and the method of conjugate gradients on a concurrent processor

NASA Technical Reports Server (NTRS)

Lyzenga, G. A.; Raefsky, A.; Hager, G. H.

1985-01-01

An algorithm for the iterative solution of finite element problems on a concurrent processor is presented. The method of conjugate gradients is used to solve the system of matrix equations, which is distributed among the processors of a MIMD computer according to an element-based spatial decomposition. This algorithm is implemented in a two-dimensional elastostatics program on the Caltech Hypercube concurrent processor. The results of tests on up to 32 processors show nearly linear concurrent speedup, with efficiencies over 90 percent for sufficiently large problems.

Investigations into Gravitational Wave Emission from Compact Body Inspiral into Massive Black Holes

NASA Technical Reports Server (NTRS)

Hughes, Scott A.

2005-01-01

In contrast to year 1 (when much of the activity associated with this grant focused upon developing our group at MIT), year 2 was a period of very focused attention on research problems. We made significant progress developing relativistic waveforms for the extreme mass ratio inspiral problem; we have pushed forward a formalism our group developed for mapping the spacetimes of massive compact objects; and, in collaboration with the Caltech group, we began to develop a framework for addressing issues in LISA data analysis for extreme mass ratio systems.

Ground-Based Calibration Support for Two Approved HST Programs

NASA Technical Reports Server (NTRS)

Stauffer, John R.

1998-01-01

This final report is a summary of the study on ground-based calibration support for two approved HST programs. A large set of new rotational periods for low mass stars in the Pleiades open cluster have been published and used to help interpret chromospheric and coronal activity indicators for low mass stars in the cluster. The Caltech/TJC/NASA Keck telescope in Hawaii has also been used to obtain spectra of brown dwarf candidates in the Pleiades. Those spectra help to derive an accurate and precise new age for that fiducial open cluster.

Radio Observations of Type Ia SN2006X

NASA Astrophysics Data System (ADS)

Soderberg, Alicia

2006-02-01

Alicia Soderberg (Caltech) reports: I observed the Type Ia supernova 2006X in NGC 4321 (IAUC 8667, CBET 393) with the Very Large Array on 2006 February 9.34 UT (approximately 2 days after optical discovery). The 2.5 hour observation at 8.46 GHz reveals no radio source coincident with the optical SN position. I place a limit on the radio flux density of 45 microJy (3 sigma). At a distance of 16 Mpc this limit corresponds to a luminosity of 1.4 x 10^25 erg/s/Hz.

Optical Reference Stars for Space Surveillance: Future Plans: Latest Developments

DTIC Science & Technology

2010-01-01

Micron All Sky Survey ( 2MASS ) has imaged the entire sky in near-infrared J(1.25m), H(1.65 m), and Ks(2.16 m) bandpasses from Mt Hopkins, Arizona...and Cerro Tololo, Chile. The 10-sigma detection levels reached 15.8, 15.1, and 14.3 mag at the J, H, and Ks bands, respectively. The 2MASS data...no proper motions for the stars. Information on 2MASS can be found at http://www.ipac.caltech.edu/ 2mass . UCAC The basis of the USNO CCD

Finite elements and the method of conjugate gradients on a concurrent processor

NASA Technical Reports Server (NTRS)

Lyzenga, G. A.; Raefsky, A.; Hager, B. H.

1984-01-01

An algorithm for the iterative solution of finite element problems on a concurrent processor is presented. The method of conjugate gradients is used to solve the system of matrix equations, which is distributed among the processors of a MIMD computer according to an element-based spatial decomposition. This algorithm is implemented in a two-dimensional elastostatics program on the Caltech Hypercube concurrent processor. The results of tests on up to 32 processors show nearly linear concurrent speedup, with efficiencies over 90% for sufficiently large problems.

Proceedings of a Symposium on Perspectives in Fluid Mechanics Held in Pasadena, California on 10-12 January 1985

DTIC Science & Technology

1988-07-29

rate of the earth times the sine of latitude. At Caltech, near latitude 34 degrees , that is a frequency of about one cycle per day. The stratification...commonly defined by N = e -z/b, since the ocean is most stratified near the surface and least stratified near the bottom. This gives a length scale t) = 1...The two jets do not terminate in strong shocks (hot spots) but appear to decay gradually with distance, petering out into a sort of plume rising

A Conversation with Franco Rasetti

NASA Astrophysics Data System (ADS)

Goodstein, Judith R.

Along with Enrico Fermi, Franco Rasetti played a key role in the rebirth of Italian physics in the 1920s and 1930s. In this interview he talks about his experiments at Caltech on the Raman effect in 1928-1929, mountain climbing, his passion for bugs, fossils, and flowers, and doing physics in Florence, Rome, Berlin-Dahlem, and Quebec. Rasetti also reminisces about the Rome school of mathematics and other scientists he has known and worked with in Europe and in North America, including Robert and Glenn Millikan, Lise Meitner, and O. M. Corbino.

SpS1-The Spitzer atlas of stellar spectra

NASA Astrophysics Data System (ADS)

Ardila, David R.; Makowiecki, W.; van Dyk, S.; Song, I.; Stauffer, J.; Rho, J.; Fajardo-Acosta, S.; Hoard, D. W.; Wachter, S.

2010-11-01

We present Spitzer Space Telescope spectra of 147 stars (R~64 - 128, λλ = 5 - 35 μm, S/N~100) covering most spectral and luminosity classes within the HR diagram. The spectra are available from the NASA/IPAC Infrared Science Archive (IRSA) and from the first author's webpage (http://web.ipac.caltech.edu/staff/ardila/Atlas/). The Atlas contains spectra of ‘typical’ stars, which may serve to refine galactic synthesis models, study stellar atmospheres, and establish a legacy for future IR missions, such as JWST.

Current drive by spheromak injection into a tokamak

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, M.R.; Bellan, P.M.

1990-04-30

We report the first observation of current drive by injection of a spheromak plasma into a tokamak (Caltech ENCORE small reasearch tokamak) due to the process of helicity injection. After an abrupt 30% increase, the tokamak current decays by a factor of 3 due to plasma cooling caused by the merging of the relatively cold spheromak with the tokamak. The tokamak density profile peaks sharply due to the injected spheromak plasma ({ital {bar n}}{sub 3} increases by a factor of 6) then becomes hollow, suggestive of an interchange instability.

SYNCHROTRON TECHNIQUES IN ENVIRONMENTAL AND FORSENIC SCIENCES

EPA Science Inventory

The application of synchrotron based research for understanding the fate of contaminants in water, soil, and atmosphere is proving to be beneficial for scientists and regulators. Drawing the connection of a contaminated site to knowledge of metal speciation provides direct eviden...

Magnetic measurements of the injector synchrotron magnets for the advanced photon source

NASA Astrophysics Data System (ADS)

Kim, S. H.; Carnegie, D. W.; Doose, C. L.; Hogrefe, R.; Kim, K.; Merl, R.; Turner, L. R.

1994-07-01

The magnetic measurement data of the dipole, quadrupole, and sextupole magnets for the Advanced Photon Source injector synchrotron are summarized. Magnet design and magnetic measurements of the field strength, field shape, and multipole coefficients are described.

Experimental studies on coherent synchrotron radiation at an emittance exchange beam line

NASA Astrophysics Data System (ADS)

Thangaraj, J. C. T.; Thurman-Keup, R.; Ruan, J.; Johnson, A. S.; Lumpkin, A. H.; Santucci, J.

2012-11-01

One of the goals of the Fermilab A0 photoinjector is to investigate experimentally the transverse to longitudinal emittance exchange (EEX) principle. Coherent synchrotron radiation in the emittance exchange line could limit the performance of the emittance exchanger at short bunch lengths. In this paper, we present experimental and simulation studies of the coherent synchrotron radiation (CSR) in the emittance exchange line at the A0 photoinjector. We report on time-resolved CSR studies using a skew-quadrupole technique. We also demonstrate the advantages of running the EEX with an energy-chirped beam.

Status of the Siberian synchrotron radiation center

NASA Astrophysics Data System (ADS)

Ancharov, A. I.; Baryshev, V. B.; Chernov, V. A.; Gentselev, A. N.; Goldenberg, B. G.; Kochubei, D. I.; Korchuganov, V. N.; Kulipanov, G. N.; Kuzin, M. V.; Levichev, E. B.; Mezentsev, N. A.; Mishnev, S. I.; Nikolenko, A. D.; Pindyurin, V. F.; Sheromov, M. A.; Tolochko, B. P.; Sharafutdinov, M. R.; Shmakov, A. N.; Vinokurov, N. A.; Vobly, P. D.; Zolotarev, K. V.

2005-05-01

Synchrotron radiation (SR) experiments at the Budker Institute of Nuclear Physics had been started in 1973, and from 1981 the Siberian Synchrotron Radiation Center (SSRC) had an official status as Research Center of the Russian Academy of Sciences. SSRC is the research center, which is open and free of tax for the research teams from Russia and abroad. In this report some technical information about the storage rings—SR sources of the Budker INP, the main directions of activity of SSRC, experimental stations, experimental works and users—is given. Development of the free electron lasers, new SR sources and insertion devices is described.

DESY II, a new injector for the DESY storage rings PETRA and DORIS II

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hemmie, G.

1983-08-01

There is a proposal to build a new 9 GeV electron synchrotron as a dedicated injector for the storage rings DORIS and PETRA. This machine will be housed in the old DESY-tunnel side-by-side with the original DESY-synchrotron. It is characterized by a separated function lattice, a 12.5 Hz repetition frequency, an all-metal vacuum chamber and a high shunt impedance rf-system. After commissioning of this new machine in 1984, the old DESY-synchrotron could be converted into a dedicated proton-accelerator as part of the injection chain for HERA.

Thickness determination of thin solid films by angle-resolved X-ray fluorescence spectrometry using monochromatized synchrotron radiation

NASA Astrophysics Data System (ADS)

Schmitt, W.; Drotbohm, P.; Rothe, J.; Hormes, J.; Ottermann, C. R.; Bange, K.

1995-05-01

Thickness measurements by the method of angle-resolved, self-ratio X-ray fluorescence spectrometry (AR/SR/XFS) have been carried out on thin solid films using monochromatized synchrotron radiation at the Bonn storage ring ELSA. Synchrotron radiation was monochromatized by means of a double-crystal monochromator and fluorescence radiation was detected by a Si(Li) semiconductor detector. The results for sample systems consisting of Au on Si, Cr on SiO2 and TiO2 on alkali-free glass are very satisfactory and agree well with results obtained by other methods.

Diffraction and Transmission Synchrotron Imaging at the German Light Source ANKA--Potential Industrial Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rack, Alexander; Weitkamp, Timm; European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble Cedex

2009-03-10

Diffraction and transmission synchrotron imaging methods have proven to be highly suitable for investigations in materials research and non-destructive evaluation. The high flux and spatial coherence of X-rays from modern synchrotron light sources allows one to work using high resolution and different contrast modalities. This article gives a short overview of different transmission and diffraction imaging methods with high potential for industrial applications, now available for commercial access via the German light source ANKA (Forschungszentrum Karlsruhe) and its new department ANKA Commercial Service (ANKA COS, http://www.anka-cos.de)

Evolution of synchrotron-radiation-based Mössbauer absorption spectroscopy for various isotopes

NASA Astrophysics Data System (ADS)

Seto, Makoto; Masuda, Ryo; Kobayashi, Yasuhiro; Kitao, Shinji; Kurokuzu, Masayuki; Saito, Makina; Hosokawa, Shuuich; Ishibashi, Hiroki; Mitsui, Takaya; Yoda, Yoshitaka; Mibu, Ko

2017-11-01

Synchrotron-radiation-based Mössbauer spectroscopy that yields absorption type Mössbauer spectra has been applied to various isotopes. This method enables the advanced measurement by using the excellent features of synchrotron radiation, such as Mössbauer spectroscopic measurement under high-pressures. Furthermore, energy selectivity of synchrotron radiation allows us to measure 40K Mössbauer spectra, of which observation is impossible by using ordinary radioactive sources because the first excited state of 40K is not populated by any radioactive parent nuclides. Moreover, this method has flexibility of the experimental setup that the measured sample can be used as a transmitter or a scatterer, depending on the sample conditions. To enhance the measurement efficiency of the spectroscopy, we developed a detection system in which a windowless avalanche photodiode (APD) detector is combined with a vacuum cryostat to detect internal conversion electrons adding to X-rays accompanied by nuclear de-excitation. In particular, by selecting the emission from the scatterer sample, depth selective synchrotron-radiation-based Mössbauer spectroscopy is possible. Furthermore, limitation of the time window in the delayed components enables us to obtain narrow linewidth in Mössbauer spectra. Measurement system that records velocity dependent time spectra and energy information simultaneously realizes the depth selective and narrow linewidth measurement.

X-Ray Structure determination of the Glycine Cleavage System Protein H of Mycobacterium tuberculosis Using An Inverse Compton Synchrotron X-Ray Source

PubMed Central

Abendroth, Jan; McCormick, Michael S.; Edwards, Thomas E.; Staker, Bart; Loewen, Roderick; Gifford, Martin; Rifkin, Jeff; Mayer, Chad; Guo, Wenjin; Zhang, Yang; Myler, Peter; Kelley, Angela; Analau, Erwin; Hewitt, Stephen Nakazawa; Napuli, Alberto J.; Kuhn, Peter; Ruth, Ronald D.; Stewart, Lance J.

2010-01-01

Structural genomics discovery projects require ready access to both X-ray and NMR instrumentation which support the collection of experimental data needed to solve large numbers of novel protein structures. The most productive X-ray crystal structure determination laboratories make extensive frequent use of tunable synchrotron X-ray light to solve novel structures by anomalous diffraction methods. This requires that frozen cryo-protected crystals be shipped to large government-run synchrotron facilities for data collection. In an effort to eliminate the need to ship crystals for data collection, we have developed the first laboratory-scale synchrotron light source capable of performing many of the state-of-the-art synchrotron applications in X-ray science. This Compact Light Source is a first-in-class device that uses inverse Compton scattering to generate X-rays of sufficient flux, tunable wavelength and beam size to allow high-resolution X-ray diffraction data collection from protein crystals. We report on benchmarking tests of X-ray diffraction data collection with hen egg white lysozyme, and the successful high-resolution X-ray structure determination of the Glycine cleavage system protein H from Mycobacterium tuberculosis using diffraction data collected with the Compact Light Source X-ray beam. PMID:20364333

Synchrotron-based X-ray microscopic studies for bioeffects of nanomaterials.

PubMed

Zhu, Ying; Cai, Xiaoqing; Li, Jiang; Zhong, Zengtao; Huang, Qing; Fan, Chunhai

2014-04-01

There have been increasing interests in studying biological effects of nanomaterials, which are nevertheless faced up with many challenges due to the nanoscale dimensions and unique chemical properties of nanomaterials. Synchrotron-based X-ray microscopy, an advanced imaging technology with high spatial resolution and excellent elemental specificity, provides a new platform for studying interactions between nanomaterials and living systems. In this article, we review the recent progress of X-ray microscopic studies on bioeffects of nanomaterials in several living systems including cells, model organisms, animals and plants. We aim to provide an overview of the state of the art, and the advantages of using synchrotron-based X-ray microscopy for characterizing in vitro and in vivo behaviors and biodistribution of nanomaterials. We also expect that the use of a combination of new synchrotron techniques should offer unprecedented opportunities for better understanding complex interactions at the nano-biological interface and accounting for unique bioeffects of nanomaterials. Synchrotron-based X-ray microscopy is a non-destructive imaging technique that enables high resolution spatial mapping of metals with elemental level detection methods. This review summarizes the current use and perspectives of this novel technique in studying the biology and tissue interactions of nanomaterials. Copyright © 2014 Elsevier Inc. All rights reserved.

PRINCIPLES OF SYNCHROTRON TECHNIQUES, POTENTIAL AND LIMITATIONS

EPA Science Inventory

Once environmental contaminants, such as arsenic, chromium, cadmium and lead, are detected, the problem becomes how to deal with them. For the past decade, researchers at the US EPA in Cincinnati have been employing synchrotron speciation methods to determine the exact chemical f...

High Fluence Synchrotron Radiation Microprobe Effects on Stardust Interstellar Dust Candidates

NASA Astrophysics Data System (ADS)

Simionovici, A.; Allen, C.; Bajt, S.; Bastien, R.; Bechtel, H.; Borg, J.; Brenker, F. E.; Bridges, J. C.; Brownlee, D. E.; Burchell, M. J.; Burghammer, M.; Butterworth, A.; Cloetens, P.; Davis, A. M.; Floss, C.; Flynn, G.; Frank, D.; Gainsforth, Z.; Grün, E.; Heck, P. R.; Hillier, J.; Hoppe, P.; Howard, L.; Huss, G. R.; Huth, J.; Kearsley, A. T.; King, A. J.; Lai, B.; Leitner, J.; Lemelle, L.; Leroux, H.; Lettieri, R.; Marchant, W.; Nittler, L.; Ogliore, R.; Postberg, F.; Sandford, S.; Sans Tresseras, J. A.; Schoonjans, T.; Schmitz, S.; Silversmit, G.; Srama, R.; Stadermann, F. J.; Stephan, T.; Stodolna, J.; Stroud, R. M.; Sutton, S.; Tucoulou, R.; Trieloff, M.; Tsou, P.; Tsuchiyama, A.; Tyliczszak, T.; Vekemans, B.; Vincze, L.; Westphal, A. J.; Zevin, D.; Zolensky, M. E.; 29,000 Stardust@Home Dusters

2011-03-01

We are presenting for the first time damage effects produced by focused high-fluence synchrotron beams on Stardust interstellar dust candidates. The damage produced on submicrometer grains shows up as particle smearing. We attribute this mainly to charging effects.

Hard X-ray Sources for the Mexican Synchrotron Project

NASA Astrophysics Data System (ADS)

Reyes-Herrera, Juan

2016-10-01

One of the principal tasks for the design of the Mexican synchrotron was to define the storage ring energy. The main criteria for choosing the energy come from studying the electromagnetic spectrum that can be obtained from the synchrotron, because the energy range of the spectrum that can be obtained will determine the applications available to the users of the future light source. Since there is a public demand of hard X-rays for the experiments in the synchrotron community users from Mexico, in this work we studied the emission spectra from some hard X-ray sources which could be the best options for the parameters of the present Mexican synchrotron design. The calculations of the flux and the brightness for one Bending Magnet and four Insertion Devices are presented; specifically, for a Superconducting Bending Magnet (SBM), a Superconducting Wiggler (SCW), an In Vacuum Short Period Undulator (IV-SPU), a Superconducting Undulator (SCU) and for a Cryogenic Permanent Magnet Undulator (CPMU). Two commonly available synchrotron radiation programs were used for the computation (XOP and SRW). From the results, it can be concluded that the particle beam energy from the current design is enough to have one or more sources of hard X-rays. Furthermore, a wide range of hard X-ray region can be covered by the analyzed sources, and the choice of each type should be based on the specific characteristics of the X-ray beam to perform the experiments at the involved beamline. This work was done within the project Fomix Conacyt-Morelos ”Plan Estrategico para la construccion y operación de un Sincrotron en Morelos” (224392).

Synchrotron Self-Compton Emission from the Crab and Other Pulsars

NASA Technical Reports Server (NTRS)

Harding, Alice K.; Kalapotharakos, Konstantinos

2015-01-01

Results of a simulation of synchrotron-self Compton (SSC) emission from a rotation-powered pulsar are presented. The radiating particles are assumed to be both accelerated primary electrons and a spectrum of electron-positron pairs produced in cascades near the polar cap. They follow trajectories in a slot gap using 3D force-free magnetic field geometry, gaining pitch angles through resonant cyclotron absorption of radio photons, radiating and scattering synchrotron emission at high altitudes out to and beyond the light cylinder. Full angular dependence of the synchrotron photon density is simulated in the scattering and all processes are treated in the inertial observer frame. Spectra for the Crab and Vela pulsars as well as two energetic millisecond pulsars, B1821-24 and B1937+21 are simulated using this model. The simulation of the Crab pulsar radiation can reproduce both the flux level and the shape of the observed optical to hard X-ray emission assuming a pair multiplicity of M+ = 3x10(exp 5), as well as the very-high- energy emission above 50 GeV detected by MAGIC and VERITAS, with both the synchrotron and SSC components reflecting the shape of the pair spectrum. Simulations of Vela, B1821-24 and B1937+21, for M+ up to 10(exp 5), do not produce pair SSC emission that is detectable by current telescopes, indicating that only Crab-like pulsars produce significant SSC components. The pair synchrotron emission matches the observed X-ray spectrum of the millisecond pulsars and the predicted peak of this emission at 1-10 MeV would be detectable with planned Compton telescopes.

Efficiency of Synchrotron Radiation from Rotation-powered Pulsars

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kisaka, Shota; Tanaka, Shuta J., E-mail: kisaka@phys.aoyama.ac.jp, E-mail: sjtanaka@center.konan-u.ac.jp

2017-03-01

Synchrotron radiation is widely considered to be the origin of the pulsed non-thermal emissions from rotation-powered pulsars in optical and X-ray bands. In this paper, we study the synchrotron radiation emitted by the created electron and positron pairs in the pulsar magnetosphere to constrain the energy conversion efficiency from the Poynting flux to the particle energy flux. We model two pair creation processes, two-photon collision, which efficiently works in young γ -ray pulsars (≲10{sup 6} year), and magnetic pair creation, which is the dominant process to supply pairs in old pulsars (≳10{sup 6} year). Using the analytical model, we derivemore » the maximum synchrotron luminosity as a function of the energy conversion efficiency. From the comparison with observations, we find that the energy conversion efficiency to the accelerated particles should be an order of unity in the magnetosphere, even though we make a number of the optimistic assumptions to enlarge the synchrotron luminosity. In order to explain the luminosity of the non-thermal X-ray/optical emission from pulsars with low spin-down luminosity L {sub sd} ≲ 10{sup 34} erg s{sup −1}, non-dipole magnetic field components should be dominant at the emission region. For the γ -ray pulsars with L {sub sd} ≲ 10{sup 35} erg s{sup −1}, observed γ -ray to X-ray and optical flux ratios are much higher than the flux ratio between curvature and the synchrotron radiations. We discuss some possibilities such as the coexistence of multiple accelerators in the magnetosphere as suggested from the recent numerical simulation results. The obtained maximum luminosity would be useful to select observational targets in X-ray and optical bands.« less

CONSTRAINTS ON THE SYNCHROTRON EMISSION MECHANISM IN GAMMA-RAY BURSTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beniamini, Paz; Piran, Tsvi, E-mail: paz.beniamini@mail.huji.ac.il, E-mail: tsvi.piran@mail.huji.ac.il

2013-05-20

We reexamine the general synchrotron model for gamma-ray bursts' (GRBs') prompt emission and determine the regime in the parameter phase space in which it is viable. We characterize a typical GRB pulse in terms of its peak energy, peak flux, and duration and use the latest Fermi observations to constrain the high-energy part of the spectrum. We solve for the intrinsic parameters at the emission region and find the possible parameter phase space for synchrotron emission. Our approach is general and it does not depend on a specific energy dissipation mechanism. Reasonable synchrotron solutions are found with energy ratios ofmore » 10{sup -4} < {epsilon}{sub B}/{epsilon}{sub e} < 10, bulk Lorentz factor values of 300 < {Gamma} < 3000, typical electrons' Lorentz factor values of 3 Multiplication-Sign 10{sup 3} < {gamma}{sub e} < 10{sup 5}, and emission radii of the order 10{sup 15} cm < R < 10{sup 17} cm. Most remarkable among those are the rather large values of the emission radius and the electron's Lorentz factor. We find that soft (with peak energy less than 100 keV) but luminous (isotropic luminosity of 1.5 Multiplication-Sign 10{sup 53}) pulses are inefficient. This may explain the lack of strong soft bursts. In cases when most of the energy is carried out by the kinetic energy of the flow, such as in the internal shocks, the synchrotron solution requires that only a small fraction of the electrons are accelerated to relativistic velocities by the shocks. We show that future observations of very high energy photons from GRBs by CTA could possibly determine all parameters of the synchrotron model or rule it out altogether.« less

The Bonn Electron Stretcher Accelerator ELSA: Past and future

NASA Astrophysics Data System (ADS)

Hillert, W.

2006-05-01

In 1953, it was decided to build a 500MeV electron synchrotron in Bonn. It came into operation 1958, being the first alternating gradient synchrotron in Europe. After five years of performing photoproduction experiments at this accelerator, a larger 2.5GeV electron synchrotron was built and set into operation in 1967. Both synchrotrons were running for particle physics experiments, until from 1982 to 1987 a third accelerator, the electron stretcher ring ELSA, was constructed and set up in a separate ring tunnel below the physics institute. ELSA came into operation in 1987, using the pulsed 2.5GeV synchrotron as pre-accelerator. ELSA serves either as storage ring producing synchrotron radiation, or as post-accelerator and pulse stretcher. Applying a slow extraction close to a third integer resonance, external electron beams with energies up to 3.5GeV and high duty factors are delivered to hadron physics experiments. Various photo- and electroproduction experiments, utilising the experimental set-ups PHOENICS, ELAN, SAPHIR, GDH and Crystal Barrel have been carried out. During the late 90's, a pulsed GaAs source of polarised electrons was constructed and set up at the accelerator. ELSA was upgraded in order to accelerate polarised electrons, compensating for depolarising resonances by applying the methods of fast tune jumping and harmonic closed orbit correction. With the experimental investigation of the GDH sum rule, the first experiment requiring a polarised beam and a polarised target was successfully performed at the accelerator. In the near future, the stretcher ring will be further upgraded to increase polarisation and current of the external electron beams. In addition, the aspects of an increase of the maximum energy to 5GeV using superconducting resonators will be investigated.

Variable magnification with Kirkpatrick-Baez optics for synchrotron X-ray microscopy

DOE PAGES

Jach, Terrence; Bakulin, Alex S.; Durbin, Stephen M.; ...

2006-05-01

In this study, we describe the distinction between the operation of a short focal length x-ray microscope forming a real image with a laboratory source (convergent illumination) and with a highly collimated intense beam from a synchrotron light source (Kohler illumination).

Biosorption of malachite green onto Haematococcus pluvialis observed through synchrotron-FTIR microspectroscopy.

PubMed

Liu, J H; Zhang, L; Zha, D C; Chen, L Q; Chen, X X; Qi, Z M

2018-06-28

Microalgae have emerged as promising biosorbents for the treatment of malachite green in wastewater. However, the underlying mechanism for the biosorption of malachite green onto microalgae is still unclear and needs further intensive study. In this work, synchrotron Fourier-transform infrared (synchrotron-FTIR) microspectroscoy in combination with biochemical assay is employed to evaluate malachite green removal efficiency (95.2%, 75.6% and 66.5%) by three stages of Haematococcus pluvialis. Meanwhile, the various vital changes of algal cells including lipids, proteins, polysaccharides and carotenoids, is distinguished and quantified in situ. This study illustrates that synchrotron-FTIR microspectroscopy is an effective and powerful tool to scrutinize the mechanism for the interactions between the malachite green dye and microalgal cells and it even provides an effective and none-invasive new approach to screen potentially proper biosorbents for the removal of dyes from wastewater. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Low-aberration beamline optics for synchrotron infrared nanospectroscopy.

PubMed

Freitas, Raul O; Deneke, Christoph; Maia, Francisco C B; Medeiros, Helton G; Moreno, Thierry; Dumas, Paul; Petroff, Yves; Westfahl, Harry

2018-04-30

Synchrotron infrared nanospectroscopy is a recently developed technique that enables new possibilities in the broadband chemical analysis of materials in the nanoscale, far beyond the diffraction limit in this frequency domain. Synchrotron infrared ports have exploited mainly the high brightness advantage provided by electron storage rings across the whole infrared range. However, optical aberrations in the beam produced by the source depth of bending magnet emission at large angles prevent infrared nanospectroscopy to reach its maximum capability. In this work we present a low-aberration optical layout specially designed and constructed for a dedicated synchrotron infrared nanospectroscopy beamline. We report excellent agreement between simulated beam profiles (from standard wave propagation and raytracing optics simulations) with experimental measurements. We report an important improvement in the infrared nanospectroscopy experiment related to the improved beamline optics. Finally, we demonstrate the performance of the nanospectroscopy endstation by measuring a hyperspectral image of a polar material and we evaluate the setup sensitivity by measuring ultra-thin polymer films down to 6 nm thick.

Micromirror-based manipulation of synchrotron x-ray beams

NASA Astrophysics Data System (ADS)

Walko, D. A.; Chen, Pice; Jung, I. W.; Lopez, D.; Schwartz, C. P.; Shenoy, G. K.; Wang, Jin

2017-08-01

Synchrotron beamlines typically use macroscopic, quasi-static optics to manipulate x-ray beams. We present the use of dynamic microelectromechanical systems-based optics (MEMS) to temporally modulate synchrotron x-ray beams. We demonstrate this concept using single-crystal torsional MEMS micromirrors oscillating at frequencies of 75 kHz. Such a MEMS micromirror, with lateral dimensions of a few hundred micrometers, can interact with x rays by operating in grazing-incidence reflection geometry; x rays are deflected only when an x-ray pulse is incident on the rotating micromirror under appropriate conditions, i.e., at an angle less than the critical angle for reflectivity. The time window for such deflections depends on the frequency and amplitude of the MEMS rotation. We demonstrate that reflection geometry can produce a time window of a few microseconds. We further demonstrate that MEMS optics can isolate x rays from a selected synchrotron bunch or group of bunches. With ray-trace simulations we explain the currently achievable time windows and suggest a path toward improvements.

Modeling challenges and approaches in simulating the Jovian synchrotron radiation belts from an in-situ perspective

NASA Astrophysics Data System (ADS)

Adumitroaie, V.; Oyafuso, F. A.; Levin, S.; Gulkis, S.; Janssen, M. A.; Santos-Costa, D.; Bolton, S. J.

2017-12-01

In order to obtain credible atmospheric composition retrieval values from Jupiter's observed radiative signature via Juno's MWR instrument, it is necessary to separate as robustly as possible the contributions from three emission sources: CMB, planet and synchrotron radiation belts. The numerical separation requires a refinement, based on the in-situ data, of a higher fidelity model for the synchrotron emission, namely the multi-parameter, multi-zonal model of Levin at al. (2001). This model employs an empirical electron energy distribution, which prior to the Juno mission, has been adjusted exclusively from VLA observations. At minimum 8 sets of perijove observations (i.e. by PJ9) have to be delivered to an inverse model for retrieval of the electron distribution parameters with the goal of matching the synchrotron emission observed along MWR's lines of sight. The challenges and approaches taken to perform this task are discussed here. The model will be continuously improved with the availability of additional information, both from the MWR and magnetometer instruments.

Simulating synchrotron radiation in accelerators including diffuse and specular reflections

DOE PAGES

Dugan, G.; Sagan, D.

2017-02-24

An accurate calculation of the synchrotron radiation flux within the vacuum chamber of an accelerator is needed for a number of applications. These include simulations of electron cloud effects and the design of radiation masking systems. To properly simulate the synchrotron radiation, it is important to include the scattering of the radiation at the vacuum chamber walls. To this end, a program called synrad3d has been developed which simulates the production and propagation of synchrotron radiation using a collection of photons. Photons generated by a charged particle beam are tracked from birth until they strike the vacuum chamber wall wheremore » the photon is either absorbed or scattered. Both specular and diffuse scattering is simulated. If a photon is scattered, it is further tracked through multiple encounters with the wall until it is finally absorbed. This paper describes the synrad3d program, with a focus on the details of its scattering model, and presents some examples of the program’s use.« less

Statistical properties of Galactic CMB foregrounds: dust and synchrotron

NASA Astrophysics Data System (ADS)

Kandel, D.; Lazarian, A.; Pogosyan, D.

2018-07-01

Recent Planck observations have revealed some of the important statistical properties of synchrotron and dust polarization, namely, the B to E mode power and temperature-E (TE) mode cross-correlation. In this paper, we extend our analysis in Kandel et al. that studied the B to E mode power ratio for polarized dust emission to include TE cross-correlation and develop an analogous formalism for synchrotron signal, all using a realistic model of magnetohydrodynamical turbulence. Our results suggest that the Planck results for both synchrotron and dust polarization can be understood if the turbulence in the Galaxy is sufficiently sub-Alfvénic. Making use of the observed poor magnetic field-density correlation, we show that the observed positive TE correlation for dust corresponds to our theoretical expectations. We also show how the B to E ratio as well as the TE cross-correlation can be used to study media magnetization, compressibility, and level of density-magnetic field correlation.

Field transients of coherent terahertz synchrotron radiation accessed via time-resolving and correlation techniques

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pohl, A.; Hübers, H.-W.; Institute of Optical Sensor Systems, German Aerospace Center

2016-03-21

Decaying oscillations of the electric field in repetitive pulses of coherent synchrotron radiation in the terahertz frequency range was evaluated by means of time-resolving and correlation techniques. Comparative analysis of real-time voltage transients of the electrical response and interferograms, which were obtained with an ultrafast zero-bias Schottky diode detector and a Martin-Puplett interferometer, delivers close values of the pulse duration. Consistent results were obtained via the correlation technique with a pair of Golay Cell detectors and a pair of resonant polarisation-sensitive superconducting detectors integrated on one chip. The duration of terahertz synchrotron pulses does not closely correlate with the durationmore » of single-cycle electric field expected for the varying size of electron bunches. We largely attribute the difference to the charge density oscillations in electron bunches and to the low-frequency spectral cut-off imposed by both the synchrotron beamline and the coupling optics of our detectors.« less

Thermal Electrons in Gamma-Ray Burst Afterglows

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ressler, Sean M.; Laskar, Tanmoy

2017-08-20

To date, nearly all multi-wavelength modeling of long-duration γ -ray bursts has ignored synchrotron radiation from the significant population of electrons expected to pass the shock without acceleration into a power-law distribution. We investigate the effect of including the contribution of thermal, non-accelerated electrons to synchrotron absorption and emission in the standard afterglow model, and show that these thermal electrons provide an additional source of opacity to synchrotron self-absorption, and yield an additional emission component at higher energies. The extra opacity results in an increase in the synchrotron self-absorption frequency by factors of 10–100 for fiducial parameters. The nature ofmore » the additional emission depends on the details of the thermal population, but is generally observed to yield a spectral peak in the optical brighter than radiation from the nonthermal population by similar factors a few seconds after the burst, remaining detectable at millimeter and radio frequencies several days later.« less

Synchrotron x-ray imaging of acoustic cavitation bubbles induced by acoustic excitation

NASA Astrophysics Data System (ADS)

Jung, Sung Yong; Park, Han Wook; Park, Sung Ho; Lee, Sang Joon

2017-04-01

The cavitation induced by acoustic excitation has been widely applied in various biomedical applications because cavitation bubbles can enhance the exchanges of mass and energy. In order to minimize the hazardous effects of the induced cavitation, it is essential to understand the spatial distribution of cavitation bubbles. The spatial distribution of cavitation bubbles visualized by the synchrotron x-ray imaging technique is compared to that obtained with a conventional x-ray tube. Cavitation bubbles with high density in the region close to the tip of the probe are visualized using the synchrotron x-ray imaging technique, however, the spatial distribution of cavitation bubbles in the whole ultrasound field is not detected. In this study, the effects of the ultrasound power of acoustic excitation and working medium on the shape and density of the induced cavitation bubbles are examined. As a result, the synchrotron x-ray imaging technique is useful for visualizing spatial distributions of cavitation bubbles, and it could be used for optimizing the operation conditions of acoustic cavitation.

Pump-probe experiments at the TEMPO beamline using the low-α operation mode of Synchrotron SOLEIL.

PubMed

Silly, Mathieu G; Ferté, Tom; Tordeux, Marie Agnes; Pierucci, Debora; Beaulieu, Nathan; Chauvet, Christian; Pressacco, Federico; Sirotti, Fausto; Popescu, Horia; Lopez-Flores, Victor; Tortarolo, Marina; Sacchi, Maurizio; Jaouen, Nicolas; Hollander, Philippe; Ricaud, Jean Paul; Bergeard, Nicolas; Boeglin, Christine; Tudu, Bharati; Delaunay, Renaud; Luning, Jan; Malinowski, Gregory; Hehn, Michel; Baumier, Cédric; Fortuna, Franck; Krizmancic, Damjan; Stebel, Luigi; Sergo, Rudi; Cautero, Giuseppe

2017-07-01

The SOLEIL synchrotron radiation source is regularly operated in special filling modes dedicated to pump-probe experiments. Among others, the low-α mode operation is characterized by shorter pulse duration and represents the natural bridge between 50 ps synchrotron pulses and femtosecond experiments. Here, the capabilities in low-α mode of the experimental set-ups developed at the TEMPO beamline to perform pump-probe experiments with soft X-rays based on photoelectron or photon detection are presented. A 282 kHz repetition-rate femtosecond laser is synchronized with the synchrotron radiation time structure to induce fast electronic and/or magnetic excitations. Detection is performed using a two-dimensional space resolution plus time resolution detector based on microchannel plates equipped with a delay line. Results of time-resolved photoelectron spectroscopy, circular dichroism and magnetic scattering experiments are reported, and their respective advantages and limitations in the framework of high-time-resolution pump-probe experiments compared and discussed.

Ultra high-speed x-ray imaging of laser-driven shock compression using synchrotron light

NASA Astrophysics Data System (ADS)

Olbinado, Margie P.; Cantelli, Valentina; Mathon, Olivier; Pascarelli, Sakura; Grenzer, Joerg; Pelka, Alexander; Roedel, Melanie; Prencipe, Irene; Laso Garcia, Alejandro; Helbig, Uwe; Kraus, Dominik; Schramm, Ulrich; Cowan, Tom; Scheel, Mario; Pradel, Pierre; De Resseguier, Thibaut; Rack, Alexander

2018-02-01

A high-power, nanosecond pulsed laser impacting the surface of a material can generate an ablation plasma that drives a shock wave into it; while in situ x-ray imaging can provide a time-resolved probe of the shock-induced material behaviour on macroscopic length scales. Here, we report on an investigation into laser-driven shock compression of a polyurethane foam and a graphite rod by means of single-pulse synchrotron x-ray phase-contrast imaging with MHz frame rate. A 6 J, 10 ns pulsed laser was used to generate shock compression. Physical processes governing the laser-induced dynamic response such as elastic compression, compaction, pore collapse, fracture, and fragmentation have been imaged; and the advantage of exploiting the partial spatial coherence of a synchrotron source for studying low-density, carbon-based materials is emphasized. The successful combination of a high-energy laser and ultra high-speed x-ray imaging using synchrotron light demonstrates the potentiality of accessing complementary information from scientific studies of laser-driven shock compression.

On the Centennial of Willy Fowler and Grote Reber: It Takes All Kinds

NASA Astrophysics Data System (ADS)

Tenn, Joseph S.

2011-01-01

William A. Fowler and Grote Reber were born in 1911, grew up in the American Midwest, and started out studying engineering. Neither ever made professional use of optical telescopes, and initially neither considered himself an astronomer. Reber was a radio engineer who followed up on Karl Jansky's surprising discovery of radio emissions from the sky by building his own radio telescope, and for several years he was the world's only radio astronomer. His discoveries showed that much new information could be obtained about the Universe by detecting and analysing what he called "cosmic static". Fowler was a nuclear physicist who took over leadership of a group at Caltech begun by C.C. Lauritsen and made the Kellogg Radiation Lab the world's leading site for learning about the reactions that power the stars and produce all but the lightest elements. He devoted most of his time in his later years to theoretical work in nuclear astrophysics. Personally, the two were quite different: Fowler, who spent more than sixty years at Caltech, was an insider, an influential member of many committees and organizations, and a president of the American Physical Society. Reber was an outsider who hardly ever worked with others and did nearly all of his astronomical research as an amateur. Fowler left more than 50 Ph.D. students, many postdoctoral fellows, two children, and a grandchild. Reber left neither academic nor biological descendants. Despite their different styles, both the radio engineer and the nuclear physicist made enormous contributions to twentieth century astronomy.

NASA Damage Map Aids Northern California Wildfire Response

NASA Image and Video Library

2017-10-18

The Advanced Rapid Imaging and Analysis (ARIA) team at NASA's Jet Propulsion Laboratory in Pasadena, California, and Caltech, also in Pasadena, created this Damage Proxy Map depicting areas in Northern California that are likely damaged (shown by red and yellow pixels) as a result of the region's current outbreak of wildfires. The map is derived from synthetic aperture radar (SAR) images from the Copernicus Sentinel-1 satellites, operated by the European Space Agency (ESA). The images were taken before (Sep. 27, 2017, 7 p.m. PDT) and after (Oct. 9, 2017, 7 p.m. PDT) the onset of the fires. The map has been provided to various agencies to aid in the wildfire response. The map covers the area within the large red polygon, and measures 155 by 106 miles (250 by 170 kilometers). The illustrative figure from the map depicted in the inset shows damage in the city of Santa Rosa. Each pixel in the Damage Proxy Map measures about 98 feet (30 meters) across. The color variation from yellow to red indicates increasingly more significant ground surface change. Preliminary validation was done by comparing to optical satellite imagery from DigitalGlobe. This Damage Proxy Map should be used as guidance to identify damaged areas, and may be less reliable over vegetated areas. Sentinel-1 data were accessed through the Copernicus Open Access Hub. The image contains modified Copernicus Sentinel data (2017), processed by ESA and analyzed by the NASA-JPL/Caltech ARIA team. This research was carried out at JPL under a contract with NASA. https://photojournal.jpl.nasa.gov/catalog/PIA22048

LISA 8 Science Organizing Committee and Local Organizing Committee LISA 8 Science Organizing Committee and Local Organizing Committee

NASA Astrophysics Data System (ADS)

2011-05-01

Science Organising Committee (SOC) Tom Abel, Stanford University Odylio Aguiar, Instituto Nacional de Pesquisas Espaciais Tal Alexander, Wizemann Institute Peter Bender, University of Colorado Pierre Binetruy, APC - College de France Sasha Buchman, Stanford University Robert Byer, Stanford University Manuela Campanelli, University of Texas Joan Centrella, NASA/Goddard Massimo Cerdonio, University of Padova Eugenio Coccia, University of Roma-2 Neil Cornish, Montana State University Michael Cruise, University of Birmingham Curt Cutler, NASA/JPL Karsten Danzmann, University of Hannover Sam Finn, Penn State University Jens Gundlach, NPL Gerhard Heinzel, Max-Planck-Institut fuer Gravitationsphysik Craig Hogan, University of Washington Jim Hough, University of Glasgow Scott Hughes, MIT Oliver Jennrich, ESTEC Philippe Jetzer, University Zurich Seiji Kawamura, National Observatory, Japan Alberto Lobo, ICE-CSIC and IEEC Avi Loeb, Harvard University Piero Madau, Lick Observatory Yannick Mellier, IAP, Paris Peter Michelson, Stanford University Guido Mueller, University of Florida Sterl Phinney, Caltech Tom Prince, NASA/JPL Doug Richstone, University of Michigan Bernard Schutz, AEI Potsdam Tuck Stebbins, NASA/Goddard Tim Sumner, Imperial College, London Ke-Xun Sun, Stanford University Kip Thorne, Caltech Michele Vallisneri, NASA/JPL Alberto Vecchio, University of Birmingham Jean-Yves Vinet, OCA, Nice Stefano Vitale, University of Trento Rai Weiss, MIT Nick White, NASA/Goddard Local Organising Committee (LOC) Sasha Buchman (Stanford University) Robert Byer (Stanford University) Sara Charbonneau-Lefort (Stanford University) Nancy Christianson (Stanford University) John Conklin (Stanford University) Dan DeBra (Stanford University) Jan Goebel (Stanford University) Vivian Drew (Stanford University) Ke-Xun Sun (Stanford University) Lucy Zhou (Stanford University) Andrea Zoellner (Stanford University)

Status of a Novel 4-Band Submm/mm Camera for the Caltech Submillimeter Observatory

NASA Astrophysics Data System (ADS)

Noroozian, Omid; Day, P.; Glenn, J.; Golwala, S.; Kumar, S.; LeDuc, H. G.; Mazin, B.; Nguyen, H. T.; Schlaerth, J.; Vaillancourt, J. E.; Vayonakis, A.; Zmuidzinas, J.

2007-12-01

Submillimeter observations are important to the understanding of galaxy formation and evolution. Determination of the spectral energy distribution in the millimeter and submillimeter regimes allows important and powerful diagnostics. To this end, we are undertaking the construction of a 4-band (750, 850, 1100, 1300 microns) 8-arcminute field of view camera for the Caltech Submillimeter Observatory. The focal plane will make use of three novel technologies: photolithographic phased array antennae, on-chip band-pass filters, and microwave kinetic inductance detectors (MKID). The phased array antenna design obviates beam-defining feed horns. On-chip band-pass filters eliminate band-defining metal-mesh filters. Together, the antennae and filters enable each spatial pixel to observe in all four bands simultaneously. MKIDs are highly multiplexable background-limited photon detectors. Readout of the MKID array will be done with software-defined radio (See poster by Max-Moerbeck et al.). This camera will provide an order-of-magnitude larger mapping speed than existing instruments and will be comparable to SCUBA 2 in terms of the detection rate for dusty sources, but complementary to SCUBA 2 in terms of wavelength coverage. We present results from an engineering run with a demonstration array, the baseline design for the science array, and the status of instrument design, construction, and testing. We anticipate the camera will be available at the CSO in 2010. This work has been supported by NASA ROSES APRA grants NNG06GG16G and NNG06GC71G, the NASA JPL Research and Technology Development Program, and the Gordon and Betty Moore Foundation.

COMMITTEES: LISA 7 Science Organizing Committee and Local Organizing Committee LISA 7 Science Organizing Committee and Local Organizing Committee

NASA Astrophysics Data System (ADS)

2009-05-01

Science Organising Committee (SOC) Pierre Binetruy, APC - College de France Massimo Cerdonio, University of Padova Karsten Danzmann, AEI/University of Hannover Mike Cruise, University of Birmingham Jim Hough, University of Glasgow Oliver Jennrich, ESTEC Philippe Jetzer, University Zurich Alberto Lobo (Chair), ICE-CSIC and IEEC Yannick Mellier, IAP, Paris Bernard Schutz, AEI Potsdam Tim Sumner, Imperial College, London Jean-Yves Vinet, OCA, Nice Stefano Vitale, University of Trento Peter Bender, University of Colorado Sasha Buchman, Stanford University Joan Centrella, NASA/Goddard Neil Cornish, Montana State University Curt Cutler, NASA/JPL Sam Finn, Penn State University Jens Gundlach, NPL Craig Hogan, University of Washington Scott Hughes, MIT Piero Madau, Lick Observatory Tom Prince, NASA/JPL Sterl Phinney, Caltech Doug Richstone, University of Michigan Tuck Stebbins, NASA/Goddard Kip Thorne, Caltech Roger Blandford, Stanford University Eugenio Coccia, University of Roma-2 Carlos F Sopuerta,ICE-CSIC and IEEC Enrique Garcia-Berro, Universitat Politècnica de Catalunya, Barcelona Seiji Kawamura, National Observatory, Japan Jay Marx, LIGO Laboratory Stephen Merkowitz, NASA/Goddard Benoit Mours, Laboratoire d'Annec Gijs Nelemans, IMAPP, Nijmegen Enric Verdaguer, University of Barcelona Clifford M Will, Washington University, St Louis Local Organising Committee (LOC) Anna Bertolín (IEEC) Priscilla Cañizares (ICE-CSIC and IEEC) Carlos F Sopuerta (ICE-CSIC and IEEC) Ivan Lloro (ICE-CSIC and IEEC),Chair Alberto Lobo (ICE-CSIC and IEEC) Nacho Mateos (ICE-CSIC and IEEC) Pilar Montes (IEEC) Miquel Nofrarias (IEEC) Juan Ramos-Castro (Universitat Politècnica de Catalunya) Josep Sanjuán (IEEC)

Shock Experiments on Basalt - Ferric Sulfate Mixes at 21 GPa & 49 GPa and their Relevance to Martian Meteorite Impact Glasses

NASA Technical Reports Server (NTRS)

Rao, M. N.; Ross, D. K.; See, T. H.; Nyquist, L. E.; Sutton, S.; Asimow, P.

2013-01-01

Large abundance of Martian atmospheric gases and neutron-induced isotopic excesses as well as Rb-Sr isotopic variations determined in some impact glasses in basaltic shergottites (e.g., Shergotty #DBS, Zagami #H1 and EET79001 #27, #8 and #104) provide definitive evidence for the occurrence of a Martian regolith component in their constituent mineral assemblages. Some of these glass-es, known as gas-rich impact-melts (GRIM), contain numerous micron-sized iron sulfide blebs along with minor amounts of iron sulfate particulates. As these GRIM glasses contain a Martian regolith component and as iron sulfates (but not sulfides) are found to occur abundantly on the Mars surface, we suggested that the sulfide blebs in GRIMs were likely generated by shock-reduction of the parental iron sulfate bearing regolith material that had been incorporated into the cavities/crevices of basaltic host rock prior to the impact event on Mars. To test whether the sulfates could be reduced to sulfides by impact shock, we carried out laboratory shock experiments on a basalt plus ferric sulfate mixture at 49 GPa at the Caltech Shock Wave Laboratory and at 21 GPa at Johnson Space Center (JSC) Experimental Impact Laboratory. The experimental details and the preliminary results for the Caltech 49 GPa experiment were presented at LPSC last year. Here, we report the results for the 21 GPa experiment at JSC and compare these results to obtain further insight into the mechanism of the bleb formation in the GRIM glasses.

Satellite Radar Detects Damage from Sept. 19, 2017 Raboso, Mexico, Quake

NASA Image and Video Library

2017-09-20

The Advanced Rapid Imaging and Analysis (ARIA) team at NASA's Jet Propulsion Laboratory in Pasadena, California, and Caltech, also in Pasadena, created this Damage Proxy Map (DPM) depicting areas of Central Mexico, including Mexico City, that are likely damaged (shown by red and yellow pixels) from the magnitude 7.1 Raboso earthquake of Sept. 19, 2017 (local time). The map is derived from synthetic aperture radar (SAR) images from the Copernicus Sentinel-1A and Sentinel-1B satellites, operated by the European Space Agency (ESA). The images were taken before (Sept. 8, 2017) and after (Sept. 20, 2017) the earthquake. The map covers an area of 109 by 106 miles (175 by 170 kilometers). Each pixel measures about 33 yards (30 meters) across. The color variation from yellow to red indicates increasingly more significant ground and building surface change. Preliminary validation was done by comparing the DPM to a crowd-sourced Google Map (https://www.google.com/maps/d/u/0/viewer?mid=1_-V97lbdgLFHpx-CtqhLWlJAnYY&ll=19.41452166501326%2C-99.16498240436704&z=16). This damage proxy map should be used as guidance to identify damaged areas, and may be less reliable over vegetated areas. Sentinel-1 data were accessed through the Copernicus Open Access Hub. The image contains modified Copernicus Sentinel data (2017), processed by ESA and analyzed by the NASA-JPL/Caltech ARIA team. This research was carried out at JPL under contract with NASA. https://photojournal.jpl.nasa.gov/catalog/PIA21963

Numerical simulation of runaway electrons: 3-D effects on synchrotron radiation and impurity-based runaway current dissipation

NASA Astrophysics Data System (ADS)

del-Castillo-Negrete, D.; Carbajal, L.; Spong, D.; Izzo, V.

2018-05-01

Numerical simulations of runaway electrons (REs) with a particular emphasis on orbit dependent effects in 3-D magnetic fields are presented. The simulations were performed using the recently developed Kinetic Orbit Runaway electron Code (KORC) that computes the full-orbit relativistic dynamics in prescribed electric and magnetic fields including radiation damping and collisions. The two main problems of interest are synchrotron radiation and impurity-based RE dissipation. Synchrotron radiation is studied in axisymmetric fields and in 3-D magnetic configurations exhibiting magnetic islands and stochasticity. For passing particles in axisymmetric fields, neglecting orbit effects might underestimate or overestimate the total radiation power depending on the direction of the radial shift of the drift orbits. For trapped particles, the spatial distribution of synchrotron radiation exhibits localized "hot" spots at the tips of the banana orbits. In general, the radiation power per particle for trapped particles is higher than the power emitted by passing particles. The spatial distribution of synchrotron radiation in stochastic magnetic fields, obtained using the MHD code NIMROD, is strongly influenced by the presence of magnetic islands. 3-D magnetic fields also introduce a toroidal dependence on the synchrotron spectra, and neglecting orbit effects underestimates the total radiation power. In the presence of magnetic islands, the radiation damping of trapped particles is larger than the radiation damping of passing particles. Results modeling synchrotron emission by RE in DIII-D quiescent plasmas are also presented. The computation uses EFIT reconstructed magnetic fields and RE energy distributions fitted to the experimental measurements. Qualitative agreement is observed between the numerical simulations and the experiments for simplified RE pitch angle distributions. However, it is noted that to achieve quantitative agreement, it is necessary to use pitch angle distributions that depart from simplified 2-D Fokker-Planck equilibria. Finally, using the guiding center orbit model (KORC-GC), a preliminary study of pellet mitigated discharges in DIII-D is presented. The dependence of RE energy decay and current dissipation on initial energy and ionization levels of neon impurities is studied. The computed decay rates are within the range of experimental observations.

Despite Appearances, Cosmic Explosions Have Common Origin, Astronomers Discover

NASA Astrophysics Data System (ADS)

2003-11-01

A Fourth of July fireworks display features bright explosions that light the sky with different colors, yet all have the same cause. They just put their explosive energy into different colors of light. Similarly, astronomers have discovered, a variety of bright cosmic explosions all have the same origin and the same amount of total energy. This is the conclusion of an international team of astronomers that used the National Science Foundation's Very Large Array (VLA) radio telescope to study the closest known gamma-ray burst earlier this year. Artist's conception of burst Artist's Conception of Twin Jets in Energetic Cosmic Explosion CREDIT: Dana Berry, SkyWorks Digital (Click on Image for Larger Version) "For some reason we don't yet understand, these explosions put greatly varying percentages of their explosive energy into the gamma-ray portion of their output," said Dale Frail, of the National Radio Astronomy Observatory (NRAO) in Socorro, NM. That means, he said, that both strong and weak gamma-ray bursts, along with X-ray flashes, which emit almost no gamma rays, are just different forms of the same cosmic beast. The research team reported their results in the November 13 issue of the scientific journal Nature. The scientists trained the VLA on a gamma-ray burst discovered using NASA's HETE-2 satellite last March 29. This burst, dubbed GRB 030329, was the closest such burst yet seen, about 2.6 billion light-years from Earth. Because of this relative proximity, the burst was bright, with visible light from its explosion reaching a level that could be seen in amateur telescopes. As the burst faded, astronomers noted an underlying distinctive signature of a supernova explosion, confirming that the event was associated with the death of a massive star. Since 1999, astronomers have known that the strong outbursts of gamma rays, X-rays, visible light and radio waves from these bursts form beams, like those from a flashlight, rather than spreading in all directions, like light from a bare bulb. The surprising result from the VLA studies of GRB 030329 is that there are two beams, not one. The scientists found that the gamma rays and the early visible-light and X-ray emission were coming from a narrow beam, while the radio waves and later visible-light emission came from another, wider beam. "The strange thing is that some explosions seem to put most of their energy into the narrow beam, while others put most or nearly all their energy into the wider beam," Frail said. "This is telling us something very fundamental about the inner workings that drive these explosions," Frail added. The mechanism producing these explosions is what scientists call a collapsar, which occurs when a giant star collapses of its own weight at the end of its normal, nuclear fusion-powered lifetime. In an ordinary supernova, such a collapse produces a neutron star. A collapsar, however, marks the death of a more-massive star and results in a black hole, a concentration of mass so dense that not even light can escape it. After the black hole forms, its powerful gravitational pull sucks the star's remaining material toward it. This material forms a spinning disk around the black hole that lasts only a few seconds. During that time, the disk ejects material outward from its poles. A jet of material moving at nearly the speed of light emits gamma rays; slower material emits radio waves and visible light. "Despite the differences in how much energy comes out in gamma rays, all these things seem to be caused by the same basic mechanism," said Edo Berger, a graduate student at Caltech and lead author of the Nature paper. "Our observations now give the data that will help us understand what causes the differences," he added. "It was astounding to suddenly realize that these apparently very different cosmic beasts all are really the same thing," said Berger. The next job, Frail said, is to learn if there are, in fact, two jets, or a single jet in which the central part encounters less resistance and thus can move outward at greater speeds. Frail pointed out that the radio observations alone had the ability to show the total energy output of the burst, thus providing the breakthrough in understanding the common thread among the different types of explosions. "The key fact is that the optical, X-Ray and gamma-ray telescopes missed 90 percent of the energy put out by this burst," Frail added. "As the VLA Expansion Project progresses and the sensitivity of the VLA improves in the coming years, it will become an even more important tool in unravelling this mystery," Frail said. "The exciting part of this new discovery is that explosions that we once thought were quite different now appear to all have a common origin," Frail concluded. "That insight, of course, gives us the new challenge of explaining how a single mechanism can make itself look so different," he added. In addition to Berger and Frail, the other authors of the paper are Professor Shri Kulkarni of Caltech; Guy Pooley of Cambridge University's Mullard Radio Astronomy Observatory; Vince McIntyre and Robin Wark, both of the Australia Telescope National Facility; Re'em Sari, associate professor of astrophysics and planetary science at Caltech; Derek Fox, a postdoctoral scholar in astronomy at Caltech; Alicia Soderberg, a graduate student in astrophysics at Caltech; Sarah Yost, a graduate student in physics at Caltech; and Paul Price, a postdoctoral scholar at the University of Hawaii's Institute for Astronomy. Berger and Soderberg earlier worked on gamma-ray-burst studies as summer students at NRAO. The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Synchrotron X-ray CT characterization of titanium parts fabricated by additive manufacturing. Part I. Morphology.

PubMed

Scarlett, Nicola Vivienne Yorke; Tyson, Peter; Fraser, Darren; Mayo, Sheridan; Maksimenko, Anton

2016-07-01

Synchrotron X-ray tomography has been applied to the study of titanium parts fabricated by additive manufacturing (AM). The AM method employed here was the Arcam EBM(®) (electron beam melting) process which uses powdered titanium alloy, Ti64 (Ti alloy with approximately 6%Al and 4%V), as the feed and an electron beam for the sintering/welding. The experiment was conducted on the Imaging and Medical Beamline of the Australian Synchrotron. Samples were chosen to examine the effect of build direction and complexity of design on the surface morphology and final dimensions of the piece.

Synchrotron FTIR Imaging For The Identification Of Cell Types Within Human Tissues

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walsh, Michael J.; Pounder, F. Nell; Nasse, Michael J.

2010-02-03

The use of synchrotron Fourier Transform Infrared spectroscopy (S-FTIR) has been shown to be a very promising tool for biomedical research. S-FTIR spectroscopy allows for the fast acquisition of infrared (IR) spectra at a spatial resolution approaching the IR diffraction limit. The development of the Infrared Environmental Imaging (IRENI) beamline at the Synchrotron Radiation Center (SRC) at the University of Wisconsin-Madison has allowed for diffraction limited imaging measurements of cells in human prostate and breast tissues. This has allowed for the identification of cell types within tissues that would otherwise not have been resolvable using conventional FTIR sources.

Discovery of an optical synchrotron jet in 3C 264

NASA Technical Reports Server (NTRS)

Crane, P.; Peletier, R.; Baxter, D.; Sparks, W. B.; Albrecht, R.; Barbieri, C.; Blades, J. C.; Boksenberg, A.; Deharveng, J. M.; Disney, M. J.

1993-01-01

Observations with the Faint Object Camera on board the Hubble Space Telescope have revealed a new optical jet in the core of the elliptical galaxy NGC 3862 (3C 264). Morphologically, this jet is similar to the synchrotron jets seen in other galaxies, as it shows knots and bifurcations. The optical spectral index is also similar to that found in other jets. Thus, the nucleus of NGC 3862 appears to contain the fifth known example of an optical synchrotron jet. Since NGC 3862 is a typical radio-loud elliptical galaxy, it seems likely that many nonthermal jets found in the radio continuum may also have optical counterparts.

Evaluation of the UFXC32k photon-counting detector for pump-probe experiments using synchrotron radiation.

PubMed

Koziol, Anna; Bordessoule, Michel; Ciavardini, Alessandra; Dawiec, Arkadiusz; Da Silva, Paulo; Desjardins, Kewin; Grybos, Pawel; Kanoute, Brahim; Laulhe, Claire; Maj, Piotr; Menneglier, Claude; Mercere, Pascal; Orsini, Fabienne; Szczygiel, Robert

2018-03-01

This paper presents the performance of a single-photon-counting hybrid pixel X-ray detector with synchrotron radiation. The camera was evaluated with respect to time-resolved experiments, namely pump-probe-probe experiments held at SOLEIL. The UFXC camera shows very good energy resolution of around 1.5 keV and allows the minimum threshold setting to be as low as 3 keV keeping the high-count-rate capabilities. Measurements of a synchrotron characteristic filling mode prove the proper separation of an isolated bunch of photons and the usability of the detector in time-resolved experiments.

SYNCHROTRON RADIO FREQUENCY PHASE CONTROL SYSTEM

DOEpatents

Plotkin, M.; Raka, E.C.; Snyder, H.S.

1963-05-01

A system for canceling varying phase changes introduced by connecting cables and control equipment in an alternating gradient synchrotron is presented. In a specific synchrotron embodiment twelve spaced accelerating stations for the proton bunches are utilized. In order to ensure that the protons receive their boost or kick at the exact instant necessary it is necessary to compensate for phase changes occurring in the r-f circuitry over the wide range of frequencies dictated by the accelerated velocities of the proton bunches. A constant beat frequency is utilized to transfer the r-f control signals through the cables and control equipment to render the phase shift constant and readily compensable. (AEC)

Examination for optimization of synchrotron radiation spectrum for the x ray depth lithography

NASA Astrophysics Data System (ADS)

Dany, Raimund

1992-06-01

The effect of reducing the vertical distribution of synchrotron radiation on its spectral distribution is examined through resin irradiation. The resulting filter effect is compared to that of absorption filters. Transmission coefficients of titanium, gold, and polyamide were calculated from linear absorption coefficients with the Beer law. The use of a diaphragm in X-ray depth lithography, which is the first step of the LIGA (Lithography Galvanoforming Molding) process, is discussed. A calorimetric device for determining the synchrotron radiation power and distribution was developed and tested. Measurements at the ELSA storage ring show a strong dependence of the vertical emittance on the electron current.

Observation of superradiant synchrotron radiation in the terahertz region

NASA Astrophysics Data System (ADS)

Billinghurst, B. E.; Bergstrom, J. C.; Dallin, L.; de Jong, M.; May, T. E.; Vogt, J. M.; Wurtz, W. A.

2013-06-01

We report the first high-resolution measurement of superradiance, using coherent synchrotron radiation in the terahertz region from the Canadian Light Source synchrotron and a Michelson interferometer with a nominal frequency resolution of 0.00096cm-1. Superradiance arises when a high degree of phase coherence exists between the radiation fields of the individual electron bunches, and manifests itself as a series of narrow spectral peaks at harmonics of the bunch frequency. We observe an enhancement factor of 16 at the spectral peaks, limited by the interferometer resolution. The spectral distribution and relative amplitudes of the superradiant peaks are modified by altering the pattern of bunches along the bunch train.

Non-Destructive Trace Element Tomography Using Europe's Brightest Synchrotron Sources (ESRF-Grenoble, DESY-Hamburg) — Towards a Better Understanding of Martian Samples

NASA Astrophysics Data System (ADS)

Brenker, F. E.; Vincze, L.; Vekemans, B.; de Poulle, E.

2018-04-01

Synchrotron sources are valuable tools to measure the main and trace element content of extraterrestrial samples. The non-destructive measurements will allow to identify important geological processes within the martian mantle and crust.

Elemental Composition of Mars Return Samples Using X-Ray Fluorescence Imaging at the National Synchrotron Light Source II

NASA Astrophysics Data System (ADS)

Thieme, J.; Hurowitz, J. A.; Schoonen, M. A.; Fogelqvist, E.; Gregerson, J.; Farley, K. A.; Sherman, S.; Hill, J.

2018-04-01

NSLS-II at BNL provides a unique and critical capability to perform assessments of the elemental composition and the chemical state of Mars returned samples using synchrotron radiation X-ray fluorescence imaging and X-ray absorption spectroscopy.

Plastique: A synchrotron radiation beamline for time resolved fluorescence in the frequency domain

NASA Astrophysics Data System (ADS)

De Stasio, Gelsomina; Zema, N.; Antonangeli, F.; Savoia, A.; Parasassi, T.; Rosato, N.

1991-06-01

PLASTIQUE is the only synchrotron radiation beamline in the world that performs time resolved fluorescence experiments in frequency domain. These experiments are extremely valuable sources of information on the structure and dynamics of molecules. We describe the beamline and some initial data.

78 FR 58569 - Notice of Meeting; NSF Synchrotron Subcommittee of the Advisory Committee for Mathematical and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-24

... NATIONAL SCIENCE FOUNDATION Notice of Meeting; NSF Synchrotron Subcommittee of the Advisory Committee for Mathematical and Physical Sciences The National Science Foundation (NSF) announces the...--Patricia Dehmer, DOE 3. Biology/biomaterials talk--importance of materials research facilities--Pupa...

Synchrotron micro-scale measurement of metal distributions in Phragmites australis and Typha latifolia root tissue from an urban brownfield site

DOE PAGES

Feng, Huan; Qian, Yu; Gallagher, Frank J.; ...

2015-11-01

Liberty State Park in New Jersey, USA, is a “brownfield” site containing various levels of contaminants. To investigate metal uptake and distributions in plants on the brownfield site, Phragmites australis and Typha latifolia were collected in Liberty State Park during the growing season (May–September) in 2011 at two sites with the high and low metal loads, respectively. The objective of this study was to understand the metal (Fe, Mn, Cu, Pb and Zn) concentration and spatial distributions in P. australis and T. latifolia root systems with micro-meter scale resolution using synchrotron X-ray microfluorescence (μXRF) and synchrotron X-ray computed microtomography (μCMT)more » techniques. The root structure measurement by synchrotron μCMT showed that high X-ray attenuation substance appeared in the epidermis. Synchrotron μXRF measurement showed that metal concentrations and distributions in the root cross-section between epidermis and vascular tissue were statistically different. Significant correlations were found between metals (Cu, Mn, Pb and Zn) and Fe in the epidermis, implying that metals were scavenged by Fe oxides. The results from this study suggest that the expression of metal transport and accumulation within the root systems may be element specific. The information derived from this study can improve our current knowledge of the wetland plant ecological function in brownfield remediation.« less

Fracture mechanics by three-dimensional crack-tip synchrotron X-ray microscopy

PubMed Central

Withers, P. J.

2015-01-01

To better understand the relationship between the nucleation and growth of defects and the local stresses and phase changes that cause them, we need both imaging and stress mapping. Here, we explore how this can be achieved by bringing together synchrotron X-ray diffraction and tomographic imaging. Conventionally, these are undertaken on separate synchrotron beamlines; however, instruments capable of both imaging and diffraction are beginning to emerge, such as ID15 at the European Synchrotron Radiation Facility and JEEP at the Diamond Light Source. This review explores the concept of three-dimensional crack-tip X-ray microscopy, bringing them together to probe the crack-tip behaviour under realistic environmental and loading conditions and to extract quantitative fracture mechanics information about the local crack-tip environment. X-ray diffraction provides information about the crack-tip stress field, phase transformations, plastic zone and crack-face tractions and forces. Time-lapse CT, besides providing information about the three-dimensional nature of the crack and its local growth rate, can also provide information as to the activation of extrinsic toughening mechanisms such as crack deflection, crack-tip zone shielding, crack bridging and crack closure. It is shown how crack-tip microscopy allows a quantitative measure of the crack-tip driving force via the stress intensity factor or the crack-tip opening displacement. Finally, further opportunities for synchrotron X-ray microscopy are explored. PMID:25624521

PROBING THE TRANSITION BETWEEN THE SYNCHROTRON AND INVERSE-COMPTON SPECTRAL COMPONENTS OF 1ES 1959+650

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bottacini, E.; Schady, P.; Rau, A.

1ES 1959+650 is one of the most remarkable high-peaked BL Lacertae objects (HBL). In 2002, it exhibited a TeV {gamma}-ray flare without a similar brightening of the synchrotron component at lower energies. This orphan TeV flare remained a mystery. We present the results of a multifrequency campaign, triggered by the INTEGRAL IBIS detection of 1ES 1959+650. Our data range from the optical to hard X-ray energies, thus covering the synchrotron and inverse-Compton components simultaneously. We observed the source with INTEGRAL, the Swift X-Ray Telescope, and the UV-Optical Telescope, and nearly simultaneously with a ground-based optical telescope. The steep spectral componentmore » at X-ray energies is most likely due to synchrotron emission, while at soft {gamma}-ray energies the hard spectral index may be interpreted as the onset of the high-energy component of the blazar spectral energy distribution (SED). This is the first clear measurement of a concave X-ray-soft {gamma}-ray spectrum for an HBL. The SED can be well modeled with a leptonic synchrotron self-Compton model. When the SED is fitted this model requires a very hard electron spectral index of q {approx} 1.85, possibly indicating the relevance of second-order Fermi acceleration.« less

Multi-scale full-orbit analysis on phase-space behavior of runaway electrons in tokamak fields with synchrotron radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Yulei; Liu, Jian, E-mail: jliuphy@ustc.edu.cn; Key Laboratory of Geospace Environment, CAS, Hefei, Anhui 230026

In this paper, the secular full-orbit simulations of runaway electrons with synchrotron radiation in tokamak fields are carried out using a relativistic volume-preserving algorithm. Detailed phase-space behaviors of runaway electrons are investigated in different dynamical timescales spanning 11 orders. In the small timescale, i.e., the characteristic timescale imposed by Lorentz force, the severely deformed helical trajectory of energetic runaway electron is witnessed. A qualitative analysis of the neoclassical scattering, a kind of collisionless pitch-angle scattering phenomena, is provided when considering the coupling between the rotation of momentum vector and the background magnetic field. In large timescale up to 1 s,more » it is found that the initial condition of runaway electrons in phase space globally influences the pitch-angle scattering, the momentum evolution, and the loss-gain ratio of runaway energy evidently. However, the initial value has little impact on the synchrotron energy limit. It is also discovered that the parameters of tokamak device, such as the toroidal magnetic field, the loop voltage, the safety factor profile, and the major radius, can modify the synchrotron energy limit and the strength of neoclassical scattering. The maximum runaway energy is also proved to be lower than the synchrotron limit when the magnetic field ripple is considered.« less

A Summer Research Program of NASA/Faculty Fellowships at the Jet Propulsion Laboratory

NASA Technical Reports Server (NTRS)

Albee, Arden

2004-01-01

The NASA Faculty Fellowship Program (NFFP) is designed to give college and university faculty members a rewarding personal as well as enriching professional experience. Fellowships are awarded to engineering and science faculty for work on collaborative research projects of mutual interest to the fellow and his or her JPL host colleague. The Jet Propulsion Laboratory (JPL) and the California Institute of Technology (Caltech) have participated in the NASA Faculty Fellowship Program for more than 25 years. Administrative offices are maintained both at the Caltech Campus and at JPL; however, most of the activity takes place at JPL. The Campus handles all fiscal matters. The duration of the program is ten continuous weeks. Fellows are required to conduct their research on-site. To be eligible to participate in the program, fellows must be a U.S. citizen and hold a teaching or research appointment at a U.S. university or college. The American Society of Engineering Education (ASEE) contracts with NASA and manages program recruitment. Over the past several years, we have made attempts to increase the diversity of the participants in the NFFP Program. A great deal of attention has been given to candidates from minority-serving institutions. There were approximately 100 applicants for the 34 positions in 2002. JPL was the first-choice location for more than half of them. Faculty from 16 minority-serving institutions participated as well as four women. The summer began with an orientation meeting that included introduction of key program personnel, and introduction of the fellows to each other. During this welcome, the fellows were briefed on their obligations to the program and to their JPL colleagues. They were also given a short historical perspective on JPL and its relationship to Caltech and NASA. All fellows received a package, which included information on administrative procedures, roster of fellows, seminar program, housing questionnaire, directions to JPL, maps of the local area, and a copy of the JPL Universe (a JPL newsletter). A calendar of events for the 2002 NFFP Program was designed to expose the fellows to the full range of JPL activities, seminars, tours, and trips to NASA Dryden, Goldstone, and Palomar Observatory. Weekly brown-bag lunches were also scheduled. The lunches provided a time for airing problems that may have arisen during the previous week, soliciting suggestions for program enhancement, announcements, and general socializing. Professor and Mrs. Albee also hosted the annual Summer Faculty Welcome Party at their home. During their ten-week tenure at JPL, the visiting faculty carried out projects in a wide variety of JPL's science, engineering, and technology disciplines, including communication, planetary science, materials research, reliability and quality assurance, astronomy, guidance and control, and micro-sensors. At the end of the NFFP Program, all fellows were required to complete a one-page summary of their summer s work. This was in addition to any documentation required by their host organization. Distribution of the final paycheck was dependent upon submission of this one-page summary and completion of NASA's NFFP evaluation in the EdCATS system. Fellows were also asked to complete a questionnaire for JPL, which enables the program administrators to make any appropriate changes to make the program more beneficial and effective for all involved. The 2002 NFFP Program at JPUCaltech was considered unanimously highly successful by both fellows and JPL colleagues. It provided a significant experience to most faculty members and fresh ideas to JPL researchers. Each year, suggestions for improvement include expansion of the program, longer terms, larger stipends, funds to support graduate students, and funds to continue collaborative research. The NASA Faculty Fellowship Program continues to occupy a significant place in JPL programs and serves to strengthen the ties between NASA, JPL, Caltech, and t academic community. This program is an important part of NASA's commitment to education. No inventions or patents were created during this program.

Obituary: Leonard Searle (1930-2010)

NASA Astrophysics Data System (ADS)

Preston, George

2011-12-01

Leonard Searle, Astronomer and Director Emeritus of Carnegie Observatories, died at his home on July 2, 2010, in Pasadena, CA, in the midst of a busy retirement that followed a long, distinguished scientific career. Searle was born on October 23, 1930, in the London suburb of Mitcham to parents of modest means. He received his Bachelor of Science degree from University of Saint Andrews in Scotland, and his PhD from Princeton University, where he met his future wife, Eleanor Millard. They were married in Princeton in 1952. Eleanor, his lifelong companion, was a distinguished medieval historian who joined the Division of the Humanities and Social Sciences at Caltech as professor in 1979. She died in 1999. Leonard joined the faculty at University of Toronto in 1953, resigning that position in 1960 to become a Senior Research Fellow at Caltech, where he worked with Jesse Greenstein and Wallace Sargent on the chemical compositions of stars. The Caltech appointment marked the beginning of a fruitful association with Sargent, with whom he published 25 papers. In 1963 Searle left Caltech to join the faculty of the Mount Stromlo Observatory in Australia. Then in 1968 he returned to Pasadena to join the staff of Carnegie Observatories, his final academic home. Several themes punctuate Searle's academic career. One of the most persistent was the abundance of helium in the very early universe, a quantity whose numerical value is of great importance for cosmology. He pursued this topic with Sargent, first in the study of old evolved "horizontal branch" stars. Later, convinced that such stars could not provide a satisfactory answer, he and Sargent turned to certain small galaxies which provided more reliable estimates of the important helium-to-hydrogen abundance ratio. In the pursuit of this answer they devised the "simple model" of chemical evolution, a formalism used by astronomers to this day. He worked with the Dutch astronomer Piet van der Kruit to construct successful models of certain spiral galaxies by careful measurements of surface brightness, and later he worked with colleagues in Pasadena to derive the abundances of chemical elements in primordial stars of our Milky Way Galaxy. His most successful venture was the formulation of a scheme for the assembly of the Milky Way Galaxy from "primordial fragments." This work, which he undertook with then-Carnegie Fellow Robert Zinn, has withstood the test of time. It has been quoted more than 1000 times since it was published in 1978. Searle accepted the Directorship of Carnegie Observatories in 1989 at a signal time in its history. Under his leadership an initial plan to build a single 8.4 meter telescope evolved finally into the construction of two 6.5 meter telescopes, operated since 2000 by a 5-institution consortium at Carnegie's Las Campanas Observatory in Chile. Searle's vital contribution to the Magellan project was his shrewd ability to hire good experts, and then to delegate authority in ways that invited their fruitful participation. All the while, Searle managed to maintain the Observatories' tradition of academic excellence, even as it was plunging into a new world of big-telescope technology. He pursued a visiting scholars program, and he used the important telescope time-allocation process to promote the intellectual growth of Carnegie scientists. His sympathy for the plight of financially strapped Eastern European astronomers took the form of support for the Polish OGLE telescope, to this day a shining success story at Carnegie's Las Campanas Observatory. Following retirement in 1996, Searle continued to follow the progress of the Observatories by frequent contact with his colleagues of many years. He and Eleanor wintered in Pasadena, and during hot Pasadena summers they escaped to their home at Somerset in the south of England. Searle maintained an avid interest in both British and American politics. He has no surviving relatives.

A Dedicated Micro-Tomography Beamline For The Australian Synchrotron

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mayo, Sheridan C.; Stevenson, Andrew W.; Wilkins, Stephen W.

2010-07-23

A dedicated micro-tomography beamline is proposed for the Australian Synchrotron. It will enable high-resolution micro-tomography with resolution below a micron and supporting phase-contrast imaging modes. A key feature of the beamline will be high-throughput/high-speed operation enabling near real-time micro-tomography.

Program for Continued Development and Use of Ocean Acoustic/GPS Geodetic Techniques

NASA Technical Reports Server (NTRS)

Spiess, Fred N.

1997-01-01

Under prior NASA grants our group, with collaboration from scientists at the CalTech Jet Propulsion Lab (JPL), visualized and carried out the initial development of a combined GPS and underwater acoustic (GPS/A) method for determining the location of points on the deep sea floor with accuracy relevant to studies of crustal deformation. Under an immediately preceding grant we built, installed and surveyed a set of the necessary seafloor marker precision transponders just seaward of the Cascadia Subduction Zone off British Columbia. The JPL group carried out processing of the GPS data.

MonALISA, an agent-based monitoring and control system for the LHC experiments

NASA Astrophysics Data System (ADS)

Balcas, J.; Kcira, D.; Mughal, A.; Newman, H.; Spiropulu, M.; Vlimant, J. R.

2017-10-01

MonALISA, which stands for Monitoring Agents using a Large Integrated Services Architecture, has been developed over the last fifteen years by California Insitute of Technology (Caltech) and its partners with the support of the software and computing program of the CMS and ALICE experiments at the Large Hadron Collider (LHC). The framework is based on Dynamic Distributed Service Architecture and is able to provide complete system monitoring, performance metrics of applications, Jobs or services, system control and global optimization services for complex systems. A short overview and status of MonALISA is given in this paper.

Shark as viewed by Sojourner Rover

NASA Technical Reports Server (NTRS)

1998-01-01

This close-up image of Shark, in the Bookshelf at the back of the Rock Garden, was taken by Sojourner Rover on Sol 75. Also in the image are Half Dome (right) and Desert Princess (lower right). At the bottom left, a thin 'crusty' soil layer has been disturbed by the rover wheels.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

Simulation of the transport of halogen species from the equatorial and mid-latitude stratosphere to the polar stratosphere in a two-dimensional model

NASA Technical Reports Server (NTRS)

Yung, Yuk L.; Shia, R. L.; Allen, M.; Zurek, R. W.; Crisp, D.; Wen, J. S.

1988-01-01

The bulk of O sub 3 destruction in the Antarctic stratosphere takes place in the lower stratosphere between 15 and 25 km. Both O sub 3 and the halogen reservoir species have their origins in the higher altitude region (20 to 30 km) in the equatorial and mid-latitude stratosphere. Using the Caltech-JPL two-dimensional residual circulation model, researchers investigate the growth of stratospheric halogen due to the increase of CFCl sub 3 and CF sub 2 Cl sub 2.

Rock Garden Mosaic

NASA Technical Reports Server (NTRS)

1997-01-01

This image mosaic of part of the 'Rock Garden' was taken by the Sojourner rover's left front camera on Sol 71 (September 14). The rock 'Shark' is at left center and 'Half Dome' is at right. Fine-scale textures on the rocks are clearly seen. Broken crust-like material is visible at bottom center.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

MINERVA: Small Telescopes, Small Planets

NASA Astrophysics Data System (ADS)

Wright, Jason; Johnson, J. A.; McCrady, N.; Swift, J.; Muirhead, P. S.; Zhao, M.; Plavchan, P.; Bottom, M.; Wittenmyer, R. A.

2014-01-01

MINERVA is four, dedicated, robotic 0.7-m telescopes at Mt. Hopkins that will use fiber optic cables to simultaneously feed a stable spectrograph to perform an intense campaign of precise velocimetry on the 80 brightest, nearest, Sun-like stars. Our strategy is to overcome astrophysical noise from stars though at-least-nightly observation, and to overcome instrumental noise limitations by combining temperature and pressure stability with an iodine calibration cell. The first telescope is being commissioned at Caltech, and site preparation at Mt. Hopkins is underway. The telescopes will also be outfitted with cameras for stellar photometric work and education and public outreach efforts.

Experiments in a Combustion-Driven Shock Tube with an Area Change

NASA Astrophysics Data System (ADS)

Schmidt, B. E.; Bobbitt, B.; Parziale, N. J.; Shepherd, J. E.

Shock tubes are versatile and useful tools for studying high temperature gas dynamics and the production of hypervelocity flows. High shock speeds are desirable for creating higher enthalpy, pressure, and temperature in the test gas which makes the study of thermo-chemical effects on fluid dynamics possible. Independent of construction and operational cost, free-piston drivers, such as the one used in the T5 facility at Caltech, give the best performance [3]. The high operational cost and long turnaround time of such a facility make a more economical option desirable for smaller-scale testing.

New theory insights and experimental opportunities in Majorana wires

NASA Astrophysics Data System (ADS)

Alicea, Jason

Over the past decade, the quest for Majorana zero modes in exotic superconductors has undergone transformational advances on the design, fabrication, detection, and characterization fronts. The field now seems primed for a new era aimed at Majorana control and readout. This talk will survey intertwined theory and experimental developments that illuminate a practical path toward these higher-level goals. In particular, I will highlight near-term opportunities for testing fundamentals of topological quantum computing and longer-term strategies for building scalable hardware. Supported by the National Science Foundation (DMR-1341822), Institute for Quantum Information and Matter, and Walter Burke Institute at Caltech.

Jessica Watkins/NASA 2017 Astronaut Candidate

NASA Image and Video Library

2017-08-22

The ranks of America’s Astronaut Corps grew by a dozen today! The twelve new NASA Astronaut Candidates have reported for duty at the Johnson Space Center in Houston to begin two years of training. Before they got to Houston we video-chatted with them all; Caltech postdoctoral fellow Jessica Watkins talks about how she became interested in science, technology, engineering and math, why she wanted to become an astronaut and where she was when she got the news that she’d achieved her dream. Learn more about the new space heroes right here: nasa.gov/2017astronauts

Modular Matrix Multiplication on a Linear Array.

DTIC Science & Technology

1983-11-01

is fl(n2). 2 Case e Irl __ (see Figure 5.2) 2 2 ,1 Y, " X2v- ’ Y2 -. x= -- ~ Y4 "i; Yin Figure 5Ŗ At t--xi, either all Gk, such that IkEA , have n...nat and Image Proceuing, IEEE Transactions on Computers, Vol. C-31, No. 10 22 (October, 1982), pp. IO0oo09. [41 H.T. Kung, Let’s Design Algorithms for...VLSI Systems, Proc. Caltech Conf. on Very Large Scale Integration: Architecture, Design , Fabrication (January, 1979), pp. 65. 90. 151 H.T. Kung, and

HUBBLE REVEALS THE HEART OF THE WHIRLPOOL GALAXY

NASA Technical Reports Server (NTRS)

2002-01-01

New images from NASA's Hubble Space Telescope are helping researchers view in unprecedented detail the spiral arms and dust clouds of a nearby galaxy, which are the birth sites of massive and luminous stars. The Whirlpool galaxy, M51, has been one of the most photogenic galaxies in amateur and professional astronomy. Easily photographed and viewed by smaller telescopes, this celestial beauty is studied extensively in a range of wavelengths by large ground- and space-based observatories. This Hubble composite image shows visible starlight as well as light from the emission of glowing hydrogen, which is associated with the most luminous young stars in the spiral arms. M51, also known as NGC 5194, is having a close encounter with a nearby companion galaxy, NGC 5195, just off the upper edge of this image. The companion's gravitational pull is triggering star formation in the main galaxy, as seen in brilliant detail by numerous, luminous clusters of young and energetic stars. The bright clusters are highlighted in red by their associated emission from glowing hydrogen gas. This Wide Field Planetary Camera 2 image enables a research group, led by Nick Scoville (Caltech), to clearly define the structure of both the cold dust clouds and the hot hydrogen and link individual clusters to their parent dust clouds. Team members include M. Polletta (U. Geneva); S. Ewald and S. Stolovy (Caltech); R. Thompson and M. Rieke (U. of Arizona). Intricate structure is also seen for the first time in the dust clouds. Along the spiral arms, dust 'spurs' are seen branching out almost perpendicular to the main spiral arms. The regularity and large number of these features suggests to astronomers that previous models of 'two-arm' spiral galaxies may need to be revisited. The new images also reveal a dust disk in the nucleus, which may provide fuel for a nuclear black hole. The team is also studying this galaxy at near-infrared wavelengths with the NICMOS instrument onboard Hubble. At these wavelengths, the dusty clouds are more transparent and the true distribution of stars is more easily seen. In addition, regions of star formation that are obscured in the optical images are newly revealed in the near-infrared images. This image was composed by the Hubble Heritage Team from Hubble archival data of M51 and is superimposed onto ground-based data taken by Travis Rector (NOAO) at the 0.9-meter telescope at the National Science Foundation's Kitt Peak National Observatory (NOAO/AURA) in Tucson, AZ. Image Credit: NASA and The Hubble Heritage Team (STScI/AURA) Acknowledgment: N. Scoville (Caltech) and T. Rector (NOAO)

The Guggenheim Aeronautics Laboratory at Caltech and the creation of the modern rocket motor (1936-1946): How the dynamics of rocket theory became reality

NASA Astrophysics Data System (ADS)

Zibit, Benjamin Seth

This thesis explores and unfolds the story of discovery in rocketry at The California Institute of Technology---specifically at Caltech's Guggenheim Aeronautics Laboratory---in the 1930s and 1940s. Caltech was home to a small group of engineering students and experimenters who, beginning in the winter of 1935--1936, formed a study and research team destined to change the face of rocket science in the United States. The group, known as the Guggenheim Aeronautics Laboratory (GALCIT, for short) Rocket Research Group, invented a new type of solid-rocket propellant, made distinct and influential discoveries in the theory of rocket combustion and design, founded the Jet Propulsion Laboratory, and incorporated the first American industrial concern devoted entirely to rocket motor production: The Aerojet Corporation. The theoretical work of team members, Frank Malina, Hsueh-shen Tsien, Homer J. Stewart, and Mark Mills, is examined in this thesis in detail. The author scrutinizes Frank Malina's doctoral thesis (both its assumptions and its mathematics), and finds that, although Malina's key assertions, his formulae, hold, his work is shown to make key assumptions about rocket dynamics which only stand the test of validity if certain approximations, rather than exact measurements, are accepted. Malina studied the important connection between motor-nozzle design and thrust; in his Ph.D. thesis, he developed mathematical statements which more precisely defined the design/thrust relation. One of Malina's colleagues on the Rocket Research Team, John Whiteside Parsons, created a new type of solid propellant in the winter of 1941--1942. This propellant, known as a composite propellant (because it simply was a relatively inert amalgam of propellant and oxidizer in non-powder form), became the forerunner of all modern solid propellants, and has become one of the seminal discoveries in the field of Twentieth Century rocketry. The latter chapters of this dissertation discuss the creation of the jet Propulsion Laboratory, the founding of the Aerojet Corporation, and emphasizes the issue of JPL's close relation to military development of the rocket becomes a core subject of this thesis. Cooperation between engineers in an academic setting and the military was not merely inevitable in the 1940s---it was actively fostered and proved quite profitable to all concerned. The deep relationship between the Guggenheim Aeronautics Laboratory and the Army Air Force was one model of the evolution of a permanent institutional edifice, weaving academic research and military end-use together. The dissertation concludes that what began as a modest effort to understand rocket theory in greater depth led within ten years to both research and development tracks which have profoundly altered the technological and military definition of modern history.

Development of Si-APD Timing Detectors for Nuclear Resonant Scattering using High-energy Synchrotron X-rays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kishimoto, Shunji; Zhang Xiaowei; Yoda, Yoshitaka

2007-01-19

A timing detector with silicon avalanche photodiodes (Si-APDs) has been developed for nuclear resonant scattering using synchrotron x-rays. The detector had four pairs of a germanium plate 0.1mm thick and a Si-APD (3 mm in dia., a depletion layer of 30-{mu}m thickness). Using synchrotron x-rays of 67.4 keV, the efficiency increased to 1.5% for the incident beam, while the efficiency was 0.76 % without the germanium converters. A measurement of SR-PAC on Ni-61 was executed by using the detector. Some other types of timing detectors are planned for x-rays of E>20 keV.

The Jovian electron spectrum and synchrotron radiation at 375 cm

NASA Technical Reports Server (NTRS)

Birmingham, T. J.

1975-01-01

The synchrotron radiation expected at Earth from the region L=2.9-5 R sub J of Jupiter's magnetosphere is calculated using the Pioneer 10 electron model. The result is approximately 21 flux units (f.u.). This value is to be compared with 6.0 + or - 0.7 f.u., the flux density of synchrotron radiation measured from Jupiter's entire magnetosphere in ground-based radio observations. Most of the radiation at 375 cm is emitted by electrons in the 1 to 10 MeV range. If the electron model used for calculations is cut off below 10 MeV, the calculated flux is reduced to approximately 4 f.u., a level compatible with the radio observations.

Local reconstruction in computed tomography of diffraction enhanced imaging

NASA Astrophysics Data System (ADS)

Huang, Zhi-Feng; Zhang, Li; Kang, Ke-Jun; Chen, Zhi-Qiang; Zhu, Pei-Ping; Yuan, Qing-Xi; Huang, Wan-Xia

2007-07-01

Computed tomography of diffraction enhanced imaging (DEI-CT) based on synchrotron radiation source has extremely high sensitivity of weakly absorbing low-Z samples in medical and biological fields. The authors propose a modified backprojection filtration(BPF)-type algorithm based on PI-line segments to reconstruct region of interest from truncated refraction-angle projection data in DEI-CT. The distribution of refractive index decrement in the sample can be directly estimated from its reconstruction images, which has been proved by experiments at the Beijing Synchrotron Radiation Facility. The algorithm paves the way for local reconstruction of large-size samples by the use of DEI-CT with small field of view based on synchrotron radiation source.

The relativistic foundations of synchrotron radiation.

PubMed

Margaritondo, Giorgio; Rafelski, Johann

2017-07-01

Special relativity (SR) determines the properties of synchrotron radiation, but the corresponding mechanisms are frequently misunderstood. Time dilation is often invoked among the causes, whereas its role would violate the principles of SR. Here it is shown that the correct explanation of the synchrotron radiation properties is provided by a combination of the Doppler shift, not dependent on time dilation effects, contrary to a common belief, and of the Lorentz transformation into the particle reference frame of the electromagnetic field of the emission-inducing device, also with no contribution from time dilation. Concluding, the reader is reminded that much, if not all, of our argument has been available since the inception of SR, a research discipline of its own standing.

Rapid cycling medical synchrotron and beam delivery system

DOEpatents

Peggs, Stephen G [Port Jefferson, NY; Brennan, J Michael [East Northport, NY; Tuozzolo, Joseph E [Sayville, NY; Zaltsman, Alexander [Commack, NY

2008-10-07

A medical synchrotron which cycles rapidly in order to accelerate particles for delivery in a beam therapy system. The synchrotron generally includes a radiofrequency (RF) cavity for accelerating the particles as a beam and a plurality of combined function magnets arranged in a ring. Each of the combined function magnets performs two functions. The first function of the combined function magnet is to bend the particle beam along an orbital path around the ring. The second function of the combined function magnet is to focus or defocus the particle beam as it travels around the path. The radiofrequency (RF) cavity is a ferrite loaded cavity adapted for high speed frequency swings for rapid cycling acceleration of the particles.

SUNY beamline facilities at the National Synchrotron Light Source (Final Report)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coppens, Philip

2003-06-22

The DOE sponsored SUNY synchrotron project has involved close cooperation among faculty at several SUNY campuses. A large number of students and postdoctoral associates have participated in its operation which was centered at the X3 beamline of the National Synchrotron Light Source at Brookhaven National Laboratory. Four stations with capabilities for Small Angle Scattering, Single Crystal and Powder and Surface diffraction and EXAFS were designed and operated with capability to perform experiments at very low as well as elevated temperatures and under high vacuum. A large amount of cutting-edge science was performed at the facility, which in addition provided excellentmore » training for students and postdoctoral scientists in the field.« less

Longitudinal phase-space coating of beam in a storage ring

NASA Astrophysics Data System (ADS)

Bhat, C. M.

2014-06-01

In this Letter, I report on a novel scheme for beam stacking without any beam emittance dilution using a barrier rf system in synchrotrons. The general principle of the scheme called longitudinal phase-space coating, validation of the concept via multi-particle beam dynamics simulations applied to the Fermilab Recycler, and its experimental demonstration are presented. In addition, it has been shown and illustrated that the rf gymnastics involved in this scheme can be used in measuring the incoherent synchrotron tune spectrum of the beam in barrier buckets and in producing a clean hollow beam in longitudinal phase space. The method of beam stacking in synchrotrons presented here is the first of its kind.

Synchrotron X-ray powder diffraction data of LASSBio-1515: A new N-acylhydrazone derivative compound

NASA Astrophysics Data System (ADS)

Costa, F. N.; Braz, D.; Ferreira, F. F.; da Silva, T. F.; Barreiro, E. J.; Lima, L. M.; Colaço, M. V.; Kuplich, L.; Barroso, R. C.

2014-02-01

In this work, synchrotron X-ray powder diffraction data allowed for a successful indexing of LASSBio-1515 compound, candidate to analgesic and anti-inflammatory activity. X-ray powder diffraction data collected in transmission and high-throughput geometries were used to analyze this compound. The X-ray wavelength of the synchrotron radiation used in this study was determined to be λ=1.55054 Å. LASSBio-1515 was found to be monoclinic with space group P21/c and unit cell parameters a=11.26255(16) Å, b=12.59785(16) Å, c=8.8540(1) Å, β=90.5972(7)° and V=1256.17(3) Å3.

On the Possibility of Acceleration of Polarized Protons in the Synchrotron Nuclotron

NASA Astrophysics Data System (ADS)

Shatunov, Yu. M.; Koop, I. A.; Otboev, A. V.; Mane, S. P.; Shatunov, P. Yu.

2018-05-01

One of the main tasks of the NICA project is to produce colliding beams of polarized protons. It is planned to accelerate polarized protons from the source to the maximum energy in the existing proton synchrotron. We consider all depolarizing spin resonances in the Nuclotron and propose methods to overcome them.

Bringing Physics, Synchrotron Light and Probing Neutrons to the Public: A Collaborative Outreach

ERIC Educational Resources Information Center

Micklavzina, Stanley; Almqvist, Monica; Sörensen, Stacey L.

2014-01-01

Stanley Micklavzina, a US physics educator on sabbatical, teams up with a Swedish national research laboratory, a synchrotron radiation experimental group and a university science centre to develop and create educational and public outreach projects. Descriptions of the physics, science centre displays and public demonstrations covering the…

Synchrotron Radiation Workshop (SRW)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chubar, O.; Elleaume, P.

2013-03-01

"Synchrotron Radiation Workshop" (SRW) is a physical optics computer code for calculation of detailed characteristics of Synchrotron Radiation (SR) generated by relativistic electrons in magnetic fields of arbitrary configuration and for simulation of the radiation wavefront propagation through optical systems of beamlines. Frequency-domain near-field methods are used for the SR calculation, and the Fourier-optics based approach is generally used for the wavefront propagation simulation. The code enables both fully- and partially-coherent radiation propagation simulations in steady-state and in frequency-/time-dependent regimes. With these features, the code has already proven its utility for a large number of applications in infrared, UV, softmore » and hard X-ray spectral range, in such important areas as analysis of spectral performances of new synchrotron radiation sources, optimization of user beamlines, development of new optical elements, source and beamline diagnostics, and even complete simulation of SR based experiments. Besides the SR applications, the code can be efficiently used for various simulations involving conventional lasers and other sources. SRW versions interfaced to Python and to IGOR Pro (WaveMetrics), as well as cross-platform library with C API, are available.« less

Bioimaging of cells and tissues using accelerator-based sources.

PubMed

Petibois, Cyril; Cestelli Guidi, Mariangela

2008-07-01

A variety of techniques exist that provide chemical information in the form of a spatially resolved image: electron microprobe analysis, nuclear microprobe analysis, synchrotron radiation microprobe analysis, secondary ion mass spectrometry, and confocal fluorescence microscopy. Linear (LINAC) and circular (synchrotrons) particle accelerators have been constructed worldwide to provide to the scientific community unprecedented analytical performances. Now, these facilities match at least one of the three analytical features required for the biological field: (1) a sufficient spatial resolution for single cell (< 1 mum) or tissue (<1 mm) analyses, (2) a temporal resolution to follow molecular dynamics, and (3) a sensitivity in the micromolar to nanomolar range, thus allowing true investigations on biological dynamics. Third-generation synchrotrons now offer the opportunity of bioanalytical measurements at nanometer resolutions with incredible sensitivity. Linear accelerators are more specialized in their physical features but may exceed synchrotron performances. All these techniques have become irreplaceable tools for developing knowledge in biology. This review highlights the pros and cons of the most popular techniques that have been implemented on accelerator-based sources to address analytical issues on biological specimens.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Jingguang; Frenkel, Anatoly; Rodriguez, Jose

Synchrotron spectroscopies offer unique advantages over conventional techniques, including higher detection sensitivity and molecular specificity, faster detection rate, and more in-depth information regarding the structural, electronic and catalytic properties under in-situ reaction conditions. Despite these advantages, synchrotron techniques are often underutilized or unexplored by the catalysis community due to various perceived and real barriers, which will be addressed in the current proposal. Since its establishment in 2005, the Synchrotron Catalysis Consortium (SCC) has coordinated significant efforts to promote the utilization of cutting-edge catalytic research under in-situ conditions. The purpose of the current renewal proposal is aimed to provide assistance, andmore » to develop new sciences/techniques, for the catalysis community through the following concerted efforts: Coordinating the implementation of a suite of beamlines for catalysis studies at the new NSLS-II synchrotron source; Providing assistance and coordination for catalysis users at an SSRL catalysis beamline during the initial period of NSLS to NSLS II transition; Designing in-situ reactors for a variety of catalytic and electrocatalytic studies; Assisting experimental set-up and data analysis by a dedicated research scientist; Offering training courses and help sessions by the PIs and co-PIs.« less

Gamma-Ray Burst Spectral Indices: Evidence for Deceleration of Synchrotron Shocks

NASA Technical Reports Server (NTRS)

Preece, R. D.; Briggs, M. S.; Giblin, T.; Mallozzi, R. S.; Pendleton, G. N.; Paciesas, W. S.; Band, D. L.

2000-01-01

The current scenario for gamma-ray bursts (GRBs) involves internal shocks for the prompt GRB emission phase and external shocks for the afterglow phase. Assuming synchrotron emission from energetic shocked electrons. GRB spectra observed with a low-energy power-law spectral index greater than -2/3 (for positive photon number indices E(sup alpha) indicate a problem with this model. The remaining spectra can test the synchrotron shock model prediction that the emission from a single distribution of electrons, cooling rapidly, is responsible for both the low-energy and high-energy power-low portions of the spectra. We find that the inferred relationship between the two spectral indices of observed GRB spectra is inconsistent with the constraints from the model, posing another problem for the synchrotron shock emission model. To overcome this problem, we describe a model where the average of -1, rather than the value of -3/2 predicted for cooling electrons. Situations where this might arise have been discussed in other contexts, and involve deceleration of the internal shocks during the GRB phase.

Specific chemical and structural damage to proteins produced by synchrotron radiation.

PubMed

Weik, M; Ravelli, R B; Kryger, G; McSweeney, S; Raves, M L; Harel, M; Gros, P; Silman, I; Kroon, J; Sussman, J L

2000-01-18

Radiation damage is an inherent problem in x-ray crystallography. It usually is presumed to be nonspecific and manifested as a gradual decay in the overall quality of data obtained for a given crystal as data collection proceeds. Based on third-generation synchrotron x-ray data, collected at cryogenic temperatures, we show for the enzymes Torpedo californica acetylcholinesterase and hen egg white lysozyme that synchrotron radiation also can cause highly specific damage. Disulfide bridges break, and carboxyl groups of acidic residues lose their definition. Highly exposed carboxyls, and those in the active site of both enzymes, appear particularly susceptible. The catalytic triad residue, His-440, in acetylcholinesterase, also appears to be much more sensitive to radiation damage than other histidine residues. Our findings have direct practical implications for routine x-ray data collection at high-energy synchrotron sources. Furthermore, they provide a direct approach for studying the radiation chemistry of proteins and nucleic acids at a detailed, structural level and also may yield information concerning putative "weak links" in a given biological macromolecule, which may be of structural and functional significance.

Recent Advances and Applications in Synchrotron X-Ray Protein Footprinting for Protein Structure and Dynamics Elucidation.

PubMed

Gupta, Sayan; Feng, Jun; Chance, Mark; Ralston, Corie

2016-01-01

Synchrotron X-ray Footprinting is a powerful in situ hydroxyl radical labeling method for analysis of protein structure, interactions, folding and conformation change in solution. In this method, water is ionized by high flux density broad band synchrotron X-rays to produce a steady-state concentration of hydroxyl radicals, which then react with solvent accessible side-chains. The resulting stable modification products are analyzed by liquid chromatography coupled to mass spectrometry. A comparative reactivity rate between known and unknown states of a protein provides local as well as global information on structural changes, which is then used to develop structural models for protein function and dynamics. In this review we describe the XF-MS method, its unique capabilities and its recent technical advances at the Advanced Light Source. We provide a comparison of other hydroxyl radical and mass spectrometry based methods with XFMS. We also discuss some of the latest developments in its usage for studying bound water, transmembrane proteins and photosynthetic protein components, and the synergy of the method with other synchrotron based structural biology methods.

An angle-resolved, wavelength-dispersive x-ray fluorescence spectrometer for depth profile analysis of ion-implanted semiconductors using synchrotron radiation

NASA Astrophysics Data System (ADS)

Schmitt, W.; Hormes, J.; Kuetgens, U.; Gries, W. H.

1992-01-01

An apparatus for angle-resolved, wavelength-dispersive x-ray fluorescence spectroscopy with synchrotron radiation has been built and tested at the beam line BN2 of the Bonn electron stretcher and accelerator (ELSA). The apparatus is to be used for nondestructive depth profile analysis of ion-implanted semiconductors as part of the multinational Versailles Project of Advanced Materials and Standards (VAMAS) project on ion-implanted reference materials. In particular, the centroid depths of depth profiles of various implants is to be determined by use of the angle-resolved signal ratio technique. First results of measurements on implants of phosphorus (100 keV, 1016 cm-2) and sulfur (200 keV, 1014 cm-2) in silicon wafers using ``white'' synchrotron radiation are presented and suggest that it should be generally possible to measure the centroid depth of an implant at dose densities as low as 1014 cm-2. Some of the apparative and technical requirements are discussed which are peculiar to the use of synchrotron radiation in general and to the use of nonmonochromatized radiation in particular.

MICROANALYSIS OF MATERIALS USING SYNCHROTRON RADIATION.

DOE Office of Scientific and Technical Information (OSTI.GOV)

JONES,K.W.; FENG,H.

2000-12-01

High intensity synchrotron radiation produces photons with wavelengths that extend from the infrared to hard x rays with energies of hundreds of keV with uniquely high photon intensities that can be used to determine the composition and properties of materials using a variety of techniques. Most of these techniques represent extensions of earlier work performed with ordinary tube-type x-ray sources. The properties of the synchrotron source such as the continuous range of energy, high degree of photon polarization, pulsed beams, and photon flux many orders of magnitude higher than from x-ray tubes have made possible major advances in the possiblemore » chemical applications. We describe here ways that materials analyses can be made using the high intensity beams for measurements with small beam sizes and/or high detection sensitivity. The relevant characteristics of synchrotron x-ray sources are briefly summarized to give an idea of the x-ray parameters to be exploited. The experimental techniques considered include x-ray fluorescence, absorption, and diffraction. Examples of typical experimental apparatus used in these experiments are considered together with descriptions of actual applications.« less

Synchrotron/crystal sample preparation

NASA Technical Reports Server (NTRS)

Johnson, R. Barry

1993-01-01

The Center for Applied Optics (CAO) of the University of Alabama in Huntsville (UAH) prepared this final report entitled 'Synchrotron/Crystal Sample Preparation' in completion of contract NAS8-38609, Delivery Order No. 53. Hughes Danbury Optical Systems (HDOS) is manufacturing the Advanced X-ray Astrophysics Facility (AXAF) mirrors. These thin-walled, grazing incidence, Wolter Type-1 mirrors, varying in diameter from 1.2 to 0.68 meters, must be ground and polished using state-of-the-art techniques in order to prevent undue stress due to damage or the presence of crystals and inclusions. The effect of crystals on the polishing and grinding process must also be understood. This involves coating special samples of Zerodur and measuring the reflectivity of the coatings in a synchrotron system. In order to gain the understanding needed on the effect of the Zerodur crystals by the grinding and polishing process, UAH prepared glass samples by cutting, grinding, etching, and polishing as required to meet specifications for witness bars for synchrotron measurements and for investigations of crystals embedded in Zerodur. UAH then characterized these samples for subsurface damage and surface roughness and figure.

Dynamic full-field infrared imaging with multiple synchrotron beams

PubMed Central

Stavitski, Eli; Smith, Randy J.; Bourassa, Megan W.; Acerbo, Alvin S.; Carr, G. L.; Miller, Lisa M.

2013-01-01

Microspectroscopic imaging in the infrared (IR) spectral region allows for the examination of spatially resolved chemical composition on the microscale. More than a decade ago, it was demonstrated that diffraction limited spatial resolution can be achieved when an apertured, single pixel IR microscope is coupled to the high brightness of a synchrotron light source. Nowadays, many IR microscopes are equipped with multi-pixel Focal Plane Array (FPA) detectors, which dramatically improve data acquisition times for imaging large areas. Recently, progress been made toward efficiently coupling synchrotron IR beamlines to multi-pixel detectors, but they utilize expensive and highly customized optical schemes. Here we demonstrate the development and application of a simple optical configuration that can be implemented on most existing synchrotron IR beamlines in order to achieve full-field IR imaging with diffraction-limited spatial resolution. Specifically, the synchrotron radiation fan is extracted from the bending magnet and split into four beams that are combined on the sample, allowing it to fill a large section of the FPA. With this optical configuration, we are able to oversample an image by more than a factor of two, even at the shortest wavelengths, making image restoration through deconvolution algorithms possible. High chemical sensitivity, rapid acquisition times, and superior signal-to-noise characteristics of the instrument are demonstrated. The unique characteristics of this setup enabled the real time study of heterogeneous chemical dynamics with diffraction-limited spatial resolution for the first time. PMID:23458231

Synchrotron Radiation Therapy from a Medical Physics point of view

NASA Astrophysics Data System (ADS)

Prezado, Y.; Adam, J. F.; Berkvens, P.; Martinez-Rovira, I.; Fois, G.; Thengumpallil, S.; Edouard, M.; Vautrin, M.; Deman, P.; Bräuer-Krisch, E.; Renier, M.; Elleaume, H.; Estève, F.; Bravin, A.

2010-07-01

Synchrotron radiation (SR) therapy is a promising alternative to treat brain tumors, whose management is limited due to the high morbidity of the surrounding healthy tissues. Several approaches are being explored by using SR at the European Synchrotron Radiation Facility (ESRF), where three techniques are under development Synchrotron Stereotactic Radiation Therapy (SSRT), Microbeam Radiation Therapy (MRT) and Minibeam Radiation Therapy (MBRT). The sucess of the preclinical studies on SSRT and MRT has paved the way to clinical trials currently in preparation at the ESRF. With this aim, different dosimetric aspects from both theoretical and experimental points of view have been assessed. In particular, the definition of safe irradiation protocols, the beam energy providing the best balance between tumor treatment and healthy tissue sparing in MRT and MBRT, the special dosimetric considerations for small field dosimetry, etc will be described. In addition, for the clinical trials, the definition of appropiate dosimetry protocols for patients according to the well established European Medical Physics recommendations will be discussed. Finally, the state of the art of the MBRT technical developments at the ESRF will be presented. In 2006 A. Dilmanian and collaborators proposed the use of thicker microbeams (0.36-0.68 mm). This new type of radiotherapy is the most recently implemented technique at the ESRF and it has been called MBRT. The main advantage of MBRT with respect to MRT is that it does not require high dose rates. Therefore it can be more easily applied and extended outside synchrotron sources in the future.

LATTICE/hor ellipsis/a beam transport program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Staples, J.

1987-06-01

LATTICE is a computer program that calculates the first order characteristics of synchrotrons and beam transport systems. The program uses matrix algebra to calculate the propagation of the betatron (Twiss) parameters along a beam line. The program draws on ideas from several older programs, notably Transport and Synch, adds many new ones and incorporates them into an interactive, user-friendly program. LATTICE will calculate the matched functions of a synchrotron lattice and display them in a number of ways, including a high resolution Tektronix graphics display. An optimizer is included to adjust selected element parameters so the beam meets a setmore » of constraints. LATTICE is a first order program, but the effect of sextupoles on the chromaticity of a synchrotron lattice is included, and the optimizer will set the sextupole strengths for zero chromaticity. The program will also calculate the characteristics of beam transport systems. In this mode, the beam parameters, defined at the start of the transport line, are propagated through to the end. LATTICE has two distinct modes: the lattice mode which finds the matched functions of a synchrotron, and the transport mode which propagates a predefined beam through a beam line. However, each mode can be used for either type of problem: the transport mode may be used to calculate an insertion for a synchrotron lattice, and the lattice mode may be used to calculate the characteristics of a long periodic beam transport system.« less

Signature of inverse Compton emission from blazars

NASA Astrophysics Data System (ADS)

Gaur, Haritma; Mohan, Prashanth; Wierzcholska, Alicja; Gu, Minfeng

2018-01-01

Blazars are classified into high-, intermediate- and low-energy-peaked sources based on the location of their synchrotron peak. This lies in infra-red/optical to ultra-violet bands for low- and intermediate-peaked blazars. The transition from synchrotron to inverse Compton emission falls in the X-ray bands for such sources. We present the spectral and timing analysis of 14 low- and intermediate-energy-peaked blazars observed with XMM-Newton spanning 31 epochs. Parametric fits to X-ray spectra help constrain the possible location of transition from the high-energy end of the synchrotron to the low-energy end of the inverse Compton emission. In seven sources in our sample, we infer such a transition and constrain the break energy in the range 0.6-10 keV. The Lomb-Scargle periodogram is used to estimate the power spectral density (PSD) shape. It is well described by a power law in a majority of light curves, the index being flatter compared to general expectation from active galactic nuclei, ranging here between 0.01 and 1.12, possibly due to short observation durations resulting in an absence of long-term trends. A toy model involving synchrotron self-Compton and external Compton (EC; disc, broad line region, torus) mechanisms are used to estimate magnetic field strength ≤0.03-0.88 G in sources displaying the energy break and infer a prominent EC contribution. The time-scale for variability being shorter than synchrotron cooling implies steeper PSD slopes which are inferred in these sources.

Design and Evaluation of a Clock Multiplexing Circuit for the SSRL Booster Accelerator Timing System - Oral Presentation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Araya, Million

2015-08-25

SPEAR3 is a 234 m circular storage ring at SLAC’s synchrotron radiation facility (SSRL) in which a 3 GeV electron beam is stored for user access. Typically the electron beam decays with a time constant of approximately 10hr due to electron lose. In order to replenish the lost electrons, a booster synchrotron is used to accelerate fresh electrons up to 3GeV for injection into SPEAR3. In order to maintain a constant electron beam current of 500mA, the injection process occurs at 5 minute intervals. At these times the booster synchrotron accelerates electrons for injection at a 10Hz rate. A 10Hzmore » 'injection ready' clock pulse train is generated when the booster synchrotron is operating. Between injection intervalswhere the booster is not running and hence the 10 Hz ‘injection ready’ signal is not present-a 10Hz clock is derived from the power line supplied by Pacific Gas and Electric (PG&E) to keep track of the injection timing. For this project I constructed a multiplexing circuit to 'switch' between the booster synchrotron 'injection ready' clock signal and PG&E based clock signal. The circuit uses digital IC components and is capable of making glitch-free transitions between the two clocks. This report details construction of a prototype multiplexing circuit including test results and suggests improvement opportunities for the final design.« less

Design and Evaluation of a Clock Multiplexing Circuit for the SSRL Booster Accelerator Timing System - Final Paper

DOE Office of Scientific and Technical Information (OSTI.GOV)

Araya, Million

2015-08-21

SPEAR3 is a 234 m circular storage ring at SLAC’s synchrotron radiation facility (SSRL) in which a 3 GeV electron beam is stored for user access. Typically the electron beam decays with a time constant of approximately 10hr due to electron lose. In order to replenish the lost electrons, a booster synchrotron is used to accelerate fresh electrons up to 3GeV for injection into SPEAR3. In order to maintain a constant electron beam current of 500mA, the injection process occurs at 5 minute intervals. At these times the booster synchrotron accelerates electrons for injection at a 10Hz rate. A 10Hzmore » 'injection ready' clock pulse train is generated when the booster synchrotron is operating. Between injection intervals-where the booster is not running and hence the 10 Hz ‘injection ready’ signal is not present-a 10Hz clock is derived from the power line supplied by Pacific Gas and Electric (PG&E) to keep track of the injection timing. For this project I constructed a multiplexing circuit to 'switch' between the booster synchrotron 'injection ready' clock signal and PG&E based clock signal. The circuit uses digital IC components and is capable of making glitch-free transitions between the two clocks. This report details construction of a prototype multiplexing circuit including test results and suggests improvement opportunities for the final design.« less

Characterization of ion-induced radiation effects in nuclear materials using synchrotron x-ray techniques

DOE PAGES

Lang, Maik; Tracy, Cameron L.; Palomares, Raul I.; ...

2015-05-01

Recent efforts to characterize the nanoscale structural and chemical modifications induced by energetic ion irradiation in nuclear materials have greatly benefited from the application of synchrotron-based x-ray diffraction (XRD) and x-ray absorption spectroscopy (XAS) techniques. Key to the study of actinide-bearing materials has been the use of small sample volumes, which are particularly advantageous, as the small quantities minimize the level of radiation exposure at the ion-beam and synchrotron user facility. This approach utilizes energetic heavy ions (energy range: 100 MeV–3 GeV) that pass completely through the sample thickness and deposit an almost constant energy per unit length along theirmore » trajectory. High energy x-rays (25–65 keV) from intense synchrotron light sources are then used in transmission geometry to analyze ion-induced structural and chemical modifications throughout the ion tracks. We describe in detail the experimental approach for utilizing synchrotron radiation (SR) to study the radiation response of a range of nuclear materials (e.g., ThO 2 and Gd 2Ti xZr 2–xO 7). Also addressed is the use of high-pressure techniques, such as the heatable diamond anvil cell, as a new means to expose irradiated materials to well-controlled high-temperature (up to 1000 °C) and/or high-pressure (up to 50 GPa) conditions. Furthermore, this is particularly useful for characterizing the annealing kinetics of irradiation-induced material modifications.« less

Time-resolved GRB spectra in the complex radiation of synchrotron and Compton processes

NASA Astrophysics Data System (ADS)

Jiang, Y. G.; Hu, S. M.; Chen, X.; Li, K.; Guo, D. F.; Li, Y. T.; Li, H. Z.; Zhao, Y. Y.; Lin, H. N.; Chang, Z.

2016-03-01

Under the steady-state condition, the spectrum of electrons is investigated by solving the continuity equation under the complex radiation of both the synchrotron and Compton processes. The resulted gamma-ray burst (GRB) spectrum is a broken power law in both the fast and slow cooling phases. On the basis of this electron spectrum, the spectral indices of the Band function in four different phases are presented. In the complex radiation frame, the detail investigation on physical parameters reveals that three models can answer the α ˜ -1 problem, which are the synchrotron plus synchrotron self-Compton in the internal and the external shock models, and the synchrotron plus the external Compton processes in the external shock model. A possible marginal to fast cooling phase transition in GRB 080916C is discussed. The time-resolved spectra in different main pulses of GRB 100724B, GRB 100826A and GRB 130606B are investigated. We found that the flux is proportional to the peak energy in almost all main pulses. A significant (5σ) correlation for Fp ˜ Ep is evident the first main pulse of GRB 100826A, and three marginally significant (3σ) correlations Fp ˜ Ep are found in main pulses of GRB 100826A and GRB 130606B. The correlation between spectral index and Ep at 3 ˜ 4σ level are observed in the first main pulse of GRB 100826A. Such correlations are possible explained in the complex radiation scenario.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kagan, Daniel; Nakar, Ehud; Piran, Tsvi, E-mail: daniel.kagan@mail.huji.ac.il

The maximum synchrotron burnoff limit of 160 MeV represents a fundamental limit to radiation resulting from electromagnetic particle acceleration in one-zone ideal plasmas. In magnetic reconnection, however, particle acceleration and radiation are decoupled because the electric field is larger than the magnetic field in the diffusion region. We carry out two-dimensional particle-in-cell simulations to determine the extent to which magnetic reconnection can produce synchrotron radiation above the burnoff limit. We use the test particle comparison (TPC) method to isolate the effects of cooling by comparing the trajectories and acceleration efficiencies of test particles incident on such a reconnection region withmore » and without cooling them. We find that the cooled and uncooled particle trajectories are typically similar during acceleration in the reconnection region, and derive an effective limit on particle acceleration that is inversely proportional to the average magnetic field experienced by the particle during acceleration. Using the calculated distribution of this average magnetic field as a function of uncooled final particle energy, we find analytically that cooling does not affect power-law particle energy spectra except at energies far above the synchrotron burnoff limit. Finally, we compare fully cooled and uncooled simulations of reconnection, confirming that the synchrotron burnoff limit does not produce a cutoff in the particle energy spectrum. Our results indicate that the TPC method accurately predicts the effects of cooling on particle acceleration in relativistic reconnection, and that, even far above the burnoff limit, the synchrotron energy of radiation produced in reconnection is not limited by cooling.« less

Synchrotron X-ray Analytical Techniques for Studying Materials Electrochemistry in Rechargeable Batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Feng; Liu, Yijin; Yu, Xiqian

Rechargeable battery technologies have ignited major breakthroughs in contemporary society, including but not limited to revolutions in transportation, electronics, and grid energy storage. The remarkable development of rechargeable batteries is largely attributed to in-depth efforts to improve battery electrode and electrolyte materials. There are, however, still intimidating challenges of lower cost, longer cycle and calendar life, higher energy density, and better safety for large scale energy storage and vehicular applications. Further progress with rechargeable batteries may require new chemistries (lithium ion batteries and beyond) and better understanding of materials electrochemistry in the various battery technologies. In the past decade, advancementmore » of battery materials has been complemented by new analytical techniques that are capable of probing battery chemistries at various length and time scales. Synchrotron X-ray techniques stand out as one of the most effective methods that allows for nearly nondestructive probing of materials characteristics such as electronic and geometric structures with various depth sensitivities through spectroscopy, scattering, and imaging capabilities. This article begins with the discussion of various rechargeable batteries and associated important scientific questions in the field, followed by a review of synchrotron X-ray based analytical tools (scattering, spectroscopy and imaging) and their successful applications (ex situ, in situ, and in operando) in gaining fundamental insights into these scientific questions. Furthermore, electron microscopy and spectroscopy complement the detection length scales of synchrotron X-ray tools, and are also discussed towards the end. We highlight the importance of studying battery materials by combining analytical techniques with complementary length sensitivities, such as the combination of X-ray absorption spectroscopy and electron spectroscopy with spatial resolution, because a sole technique may lead to biased and inaccurate conclusions. We then discuss the current progress of experimental design for synchrotron experiments and methods to mitigate beam effects. Finally, a perspective is provided to elaborate how synchrotron techniques can impact the development of next-generation battery chemistries.« less

Synchrotron X-ray Analytical Techniques for Studying Materials Electrochemistry in Rechargeable Batteries

DOE PAGES

Lin, Feng; Liu, Yijin; Yu, Xiqian; ...

2017-08-30

Rechargeable battery technologies have ignited major breakthroughs in contemporary society, including but not limited to revolutions in transportation, electronics, and grid energy storage. The remarkable development of rechargeable batteries is largely attributed to in-depth efforts to improve battery electrode and electrolyte materials. There are, however, still intimidating challenges of lower cost, longer cycle and calendar life, higher energy density, and better safety for large scale energy storage and vehicular applications. Further progress with rechargeable batteries may require new chemistries (lithium ion batteries and beyond) and better understanding of materials electrochemistry in the various battery technologies. In the past decade, advancementmore » of battery materials has been complemented by new analytical techniques that are capable of probing battery chemistries at various length and time scales. Synchrotron X-ray techniques stand out as one of the most effective methods that allows for nearly nondestructive probing of materials characteristics such as electronic and geometric structures with various depth sensitivities through spectroscopy, scattering, and imaging capabilities. This article begins with the discussion of various rechargeable batteries and associated important scientific questions in the field, followed by a review of synchrotron X-ray based analytical tools (scattering, spectroscopy and imaging) and their successful applications (ex situ, in situ, and in operando) in gaining fundamental insights into these scientific questions. Furthermore, electron microscopy and spectroscopy complement the detection length scales of synchrotron X-ray tools, and are also discussed towards the end. We highlight the importance of studying battery materials by combining analytical techniques with complementary length sensitivities, such as the combination of X-ray absorption spectroscopy and electron spectroscopy with spatial resolution, because a sole technique may lead to biased and inaccurate conclusions. We then discuss the current progress of experimental design for synchrotron experiments and methods to mitigate beam effects. Finally, a perspective is provided to elaborate how synchrotron techniques can impact the development of next-generation battery chemistries.« less

SOLEIL shining on the solution-state structure of biomacromolecules by synchrotron X-ray footprinting at the Metrology beamline.

PubMed

Baud, A; Aymé, L; Gonnet, F; Salard, I; Gohon, Y; Jolivet, P; Brodolin, K; Da Silva, P; Giuliani, A; Sclavi, B; Chardot, T; Mercère, P; Roblin, P; Daniel, R

2017-05-01

Synchrotron X-ray footprinting complements the techniques commonly used to define the structure of molecules such as crystallography, small-angle X-ray scattering and nuclear magnetic resonance. It is remarkably useful in probing the structure and interactions of proteins with lipids, nucleic acids or with other proteins in solution, often better reflecting the in vivo state dynamics. To date, most X-ray footprinting studies have been carried out at the National Synchrotron Light Source, USA, and at the European Synchrotron Radiation Facility in Grenoble, France. This work presents X-ray footprinting of biomolecules performed for the first time at the X-ray Metrology beamline at the SOLEIL synchrotron radiation source. The installation at this beamline of a stopped-flow apparatus for sample delivery, an irradiation capillary and an automatic sample collector enabled the X-ray footprinting study of the structure of the soluble protein factor H (FH) from the human complement system as well as of the lipid-associated hydrophobic protein S3 oleosin from plant seed. Mass spectrometry analysis showed that the structural integrity of both proteins was not affected by the short exposition to the oxygen radicals produced during the irradiation. Irradiated molecules were subsequently analysed using high-resolution mass spectrometry to identify and locate oxidized amino acids. Moreover, the analyses of FH in its free state and in complex with complement C3b protein have allowed us to create a map of reactive solvent-exposed residues on the surface of FH and to observe the changes in oxidation of FH residues upon C3b binding. Studies of the solvent accessibility of the S3 oleosin show that X-ray footprinting offers also a unique approach to studying the structure of proteins embedded within membranes or lipid bodies. All the biomolecular applications reported herein demonstrate that the Metrology beamline at SOLEIL can be successfully used for synchrotron X-ray footprinting of biomolecules.

Understanding the Differences in Molecular Conformation of Carbohydrate and Protein in Endosperm Tissues of Grains with Different Biodegradation Kinetics Using Advanced Synchrotron Technology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, P.; Block, H; Doiron, K

Conventional 'wet' chemical analyses rely heavily on the use of harsh chemicals and derivatization, thereby altering native seed structures leaving them unable to detect any original inherent structures within an intact tissue sample. A synchrotron is a giant particle accelerator that turns electrons into light (million times brighter than sunlight) which can be used to study the structure of materials at the molecular level. Synchrotron radiation-based Fourier transform IR microspectroscopy (SR-FTIRM) has been developed as a rapid, direct, non-destructive and bioanalytical technique. This technique, taking advantage of the brightness of synchrotron light and a small effective source size, is capablemore » of exploring the molecular chemistry within the microstructures of a biological tissue without the destruction of inherent structures at ultraspatial resolutions within cellular dimensions. This is in contrast to traditional 'wet' chemical methods, which, during processing for analysis, often result in the destruction of the intrinsic structures of feeds. To date there has been very little application of this technique to the study of plant seed tissue in relation to nutrient utilization. The objective of this study was to use novel synchrotron radiation-based technology (SR-FTIRM) to identify the differences in the molecular chemistry and conformation of carbohydrate and protein in various plant seed endosperms within intact tissues at cellular and subcellular level from grains with different biodegradation kinetics. Barley grain (cv. Harrington) with a high rate (31.3%/h) and extent (78%), corn grain (cv. Pioneer) with a low rate (9.6%/h) and extent of (57%), and wheat grain (cv. AC Barrie) with an intermediate rate (23%/h) and extent (72%) of ruminal DM degradation were selected for evaluation. SR-FTIRM evaluations were performed at the National Synchrotron Light Source at the Brookhaven National Laboratory (Brookhaven, NY). These results suggest that SR-FTIRM plus the multivariate analyses can be used to identify spectral features associated with the molecular structure of endosperm from grains with different biodegradation kinetics, especially in relation to protein structure. The Novel synchrotron radiation-based bioanalytical technique provides a new approach for plant seed structural molecular studies at ultraspatial resolution and within intact tissue in relation to nutrient availability.« less

6th international conference on biophysics and synchrotron radiation. Program/Abstracts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pittroff, Connie; Strasser, Susan Barr

1999-08-03

This STI product consists of the Program/Abstracts book that was prepared for the participants in the Sixth International Conference on Biophysics and Synchrotron Radiation that was held August 4-8, 1998, at the Advanced Photon Source, Argonne National Laboratory. This book contains the full conference program and abstracts of the scientific presentations.

X-ray diffraction imaging (topography) of electroopticcrystals by synchrotron radiation

NASA Technical Reports Server (NTRS)

Steiner, Bruce; Kuriyama, Masao; Dobbyn, Ronald C.; Laor, Uri

1988-01-01

Information of special interest to crystal growers and device physicists now available from monochromatic synchrotron diffraction imaging (topography) is reviewed. Illustrations are taken from a variety of electro-optic crystals. Aspects of the detailed understanding of crystal growth processes obtainable from carefully selected samples are described. Finally, new experimental opportunities now available for exploitation are indicated.

Assessment of Mechanisms for Jovian Synchrotron Variability Associated with Comet SL-9

NASA Technical Reports Server (NTRS)

Bolton, S. J.; Thorne, R. M.

1995-01-01

The impact comet SL-9 with Jupiter induced a number of variations in Jupiter's synchrotron radiation, including an increase in emission intensity, spectral changes, and a possible broadening in the latitudinal distribution of the emission. Considered are three potential mechanisms for inducing such effects (electron acceleration, radial diffusion, and pitch-angle scattering), and their consequences.

Polarized e-bunch acceleration at Cornell RCS: Tentative tracking simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meot, F.; Ptitsyn, V.; Ranjbar, V.

2017-10-19

An option as an injector into eRHIC electron storage ring is a rapid-cyclic synchrotron (RCS). Rapid acceleration of polarized electron bunches has never been done, Cornell synchrotron might lend itself to dedicated tests, which is to be first explored based on numerical investigations. This paper is a very preliminary introduction to the topic.

National Synchrotron Light Source II

ScienceCinema

Hill, John; Dooryhee, Eric; Wilkins, Stuart; Miller, Lisa; Chu, Yong

2018-01-16

NSLS-II is a synchrotron light source helping researchers explore solutions to the grand energy challenges faced by the nation, and open up new regimes of scientific discovery that will pave the way to discoveries in physics, chemistry, and biology — advances that will ultimately enhance national security and help drive the development of abundant, safe, and clean energy technologies.

Major Facilities for Materials Research and Related Disciplines.

ERIC Educational Resources Information Center

National Academy of Sciences - National Research Council, Washington, DC. Commission on Physical Sciences, Mathematics, and Resources.

This report presents priorities for new facilities and new capabilities at existing facilities with initial costs of at least $5 million. The new facilities in order of priority are: (1) a 6 GeV synchrotron radiation facility; (2) an advanced steady state neutron facility; (3) a 1 to 2 GeV synchrotron radiation facility; and (4) a high intensity…

Practical application of noise diffusion in U-70 synchrotron

NASA Astrophysics Data System (ADS)

Ivanov, S. V.; Lebedev, O. P.

2016-12-01

This paper briefly outlines the physical substantiation and the engineering implementation of technological systems in the U-70 synchrotron based on controllable noise diffusion of the beam. They include two systems of stochastic slow beam extraction (for high and intermediate energy) and the system of longitudinal noise RF gymnastics designated for flattening the bunch distribution over the azimuth.

Coherent synchrotron radiation by electrons moving on circular orbits

DOE PAGES

Cai, Yunhai

2017-06-14

Here, we study coherent synchrotron radiation by electrons in the Frenet-Serret coordinate system with a constant curvature 1/ρ. Based on the Hamiltonian in the Courant-Synder theory of particle accelerators, we find in general that the transverse force is essentially the Lorentz force but with a substitution of the transverse magnetic field B x,y → (1+x/ρ)B x,y, where x and y are the transverse positions. The curvature term provides us a key to derive the point-charge wakefield explicitly in terms of the incomplete elliptic integrals of the first and second kind, resulting in a steady-state theory of the coherent synchrotron radiationmore » in two-dimensional free space.« less

Medical imaging with synchrotron radiation

NASA Astrophysics Data System (ADS)

Rubenstein, Edward

1984-05-01

The present methods of detecting coronary artery disease before it causes serious heart damage or sudden death are unsatisfactory, because of the insensitivity of the screening tests and excessive risks and costs of the invasive coronary arteriographic technique. A number of other diagnostic approaches have been tried, but none has succeeded to date in providing the needed detailed information about the status of the coronary circulation. The intensity, monochromaticity and tunability of synchrotron radiation are well-suited for iodine K edge dichromographic angiography. In vivo images of the left anterior descending coronary artery of the dog have been recorded using synchrotron X-ray beams in this manner. Beams wide enough to record the image of the entire human heart in a single scanned swath are now under design.

Synchrotron Radiation from Outer Space and the Chandra X-Ray Observatory

NASA Technical Reports Server (NTRS)

Weisskopf, M. C.

2006-01-01

The universe provides numerous extremely interesting astrophysical sources of synchrotron X radiation. The Chandra X-ray Observatory and other X-ray missions provide powerful probes of these and other cosmic X-ray sources. Chandra is the X-ray component of NASA's Great Observatory Program which also includes the Hubble Space telescope, the Spitzer Infrared Telescope Facility, and the now defunct Compton Gamma-Ray Observatory. The Chandra X-Ray Observatory provides the best angular resolution (sub-arcsecond) of any previous, current, or planned (for the foreseeable near future) space-based X-ray instrumentation. We present here a brief overview of the technical capability of this X-Ray observatory and some of the remarkable discoveries involving cosmic synchrotron sources.

Pure-type superconducting permanent-magnet undulator.

PubMed

Tanaka, Takashi; Tsuru, Rieko; Kitamura, Hideo

2005-07-01

A novel synchrotron radiation source is proposed that utilizes bulk-type high-temperature superconductors (HTSCs) as permanent magnets (PMs) by in situ magnetization. Arrays of HTSC blocks magnetized by external magnetic fields are placed below and above the electron path instead of conventional PMs, generating a periodic magnetic field with an offset. Two methods are presented to magnetize the HTSCs and eliminate the field offset, enabling the HTSC arrays to work as a synchrotron radiation source. An analytical formula to calculate the peak field achieved in a device based on this scheme is derived in a two-dimensional form for comparison with synchrotron radiation sources using conventional PMs. Experiments were performed to demonstrate the principle of the proposed scheme and the results have been found to be very promising.

Nuclear Bragg scattering studies in [sup 57]Fe with synchrotron radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haustein, P.E.

1993-01-01

Studies of nuclear Bragg x-ray scattering of synchrotron radiation, using crystals of [alpha]-[sup 57]Fe[sub 2]O[sub 3], have been carried out at the NSLS at Brookhaven National Laboratory and at the Cornell University CHESS facility. These studies have demonstrated that nuclear resonance states can be used to produce filtered x-ray beams which have extremely narrow bandwidth, small angular divergence and unique polarization and temporal properties. this combination of characteristics, unobtainable with radioactive sources, makes synchrotron-based Moessbauer spectroscopy feasible and is an important complement to existing methods. A review of the experimental methodology is presented. As well as come suggestions for fullermore » exploitation of this new technique.« less

Nuclear Bragg scattering studies in {sup 57}Fe with synchrotron radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haustein, P.E.

1993-03-01

Studies of nuclear Bragg x-ray scattering of synchrotron radiation, using crystals of {alpha}-{sup 57}Fe{sub 2}O{sub 3}, have been carried out at the NSLS at Brookhaven National Laboratory and at the Cornell University CHESS facility. These studies have demonstrated that nuclear resonance states can be used to produce filtered x-ray beams which have extremely narrow bandwidth, small angular divergence and unique polarization and temporal properties. this combination of characteristics, unobtainable with radioactive sources, makes synchrotron-based Moessbauer spectroscopy feasible and is an important complement to existing methods. A review of the experimental methodology is presented. As well as come suggestions for fullermore » exploitation of this new technique.« less

Time-resolved structural studies at synchrotrons and X-ray free electron lasers: opportunities and challenges

PubMed Central

Neutze, Richard; Moffat, Keith

2012-01-01

X-ray free electron lasers (XFELs) are potentially revolutionary X-ray sources because of their very short pulse duration, extreme peak brilliance and high spatial coherence, features that distinguish them from today’s synchrotron sources. We review recent time-resolved Laue diffraction and time-resolved wide angle X-ray scattering (WAXS) studies at synchrotron sources, and initial static studies at XFELs. XFELs have the potential to transform the field of time-resolved structural biology, yet many challenges arise in devising and adapting hardware, experimental design and data analysis strategies to exploit their unusual properties. Despite these challenges, we are confident that XFEL sources are poised to shed new light on ultrafast protein reaction dynamics. PMID:23021004

Angular behavior of synchrotron radiation harmonics.

PubMed

Bagrov, V G; Bulenok, V G; Gitman, D M; Jara, Jose Acosta; Tlyachev, V B; Jarovoi, A T

2004-04-01

The detailed analysis of angular dependence of the synchrotron radiation (SR) is presented. Angular distributions of linear and circular polarization integrated over all harmonics, well known for relativistic electron energies, are extended to include radiation from electrons that are not fully relativistic. In particular, we analyze the angular dependence of the integral SR intensity and peculiarities of the angular dependence of the first harmonics SR. Studying spectral SR intensities, we have discovered their unexpected angular behavior, completely different from that of the integral SR intensity; namely, for any given synchrotron frequency, maxima of the spectral SR intensities recede from the orbit plane with increasing particle energy. Thus, in contrast with the integral SR intensity, the spectral ones have the tendency to deconcentrate themselves on the orbit plane.

Multielemental analysis of samples from patients with dermatological pathologies using synchrotron radiation

NASA Astrophysics Data System (ADS)

Soares, J. C. A. C. R.; Canellas, C. G. L.; Anjos, M. J.; Lopes, R. T.

2014-02-01

Using synchrotron radiation total X-ray fluorescence (SRTXRF) technique, the concentrations of trace elements were measured in four skin lesions: seborrheic keratosis, fibroepithelial polyp, cherry angioma and dermatosis papulosa nigra. The concentrations of P, S, K, Ca, Fe, Cu, Zn and Rb were evaluated in 62 pairs of lesions and healthy samples, each one having been collected from the same patient. The results revealed significant differences of P, Ca, K, Fe and Cu levels as well as a common trend in their variations between lesion and control samples among the skin diseases. This study revealed a powerful tool that can be useful for skin disorders research. The measurements were conducted at Brazilian National Synchrotron Light Laboratory (LNLS).

SYNCHROTRON ORIGIN OF THE TYPICAL GRB BAND FUNCTION—A CASE STUDY OF GRB 130606B

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Bin-Bin; Briggs, Michael S.; Uhm, Z. Lucas

2016-01-10

We perform a time-resolved spectral analysis of GRB 130606B within the framework of a fast-cooling synchrotron radiation model with magnetic field strength in the emission region decaying with time, as proposed by Uhm and Zhang. The data from all time intervals can be successfully fit by the model. The same data can be equally well fit by the empirical Band function with typical parameter values. Our results, which involve only minimal physical assumptions, offer one natural solution to the origin of the observed GRB spectra and imply that, at least some, if not all, Band-like GRB spectra with typical Bandmore » parameter values can indeed be explained by synchrotron radiation.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feng, Huan; Zhang, Weiguo; Qian, Yu

This study investigates the distributions of Br, Ca, Cl, Cr, Cu, K, Fe, Mn, Pb, Ti, V and Zn inPhragmites australisroot system and the function of Fe nanoparticles in scavenging metals in the root epidermis using synchrotron X-ray microfluorescence, synchrotron transmission X-ray microscope measurement and synchrotron X-ray absorption near-edge structure techniques. The purpose of this study is to understand the mobility of metals in wetland plant root systems after their uptake from rhizosphere soils.Phragmites australissamples were collected in the Yangtze River intertidal zone in July 2013. The results indicate that Fe nanoparticles are present in the root epidermis and thatmore » other metals correlate significantly with Fe, suggesting that Fe nanoparticles play an important role in metal scavenging in the epidermis.« less

New synchrotron powder diffraction facility for long-duration experiments

PubMed Central

Murray, Claire A.; Potter, Jonathan; Day, Sarah J.; Baker, Annabelle R.; Thompson, Stephen P.; Kelly, Jon; Morris, Christopher G.; Tang, Chiu C.

2017-01-01

A new synchrotron X-ray powder diffraction instrument has been built and commissioned for long-duration experiments on beamline I11 at Diamond Light Source. The concept is unique, with design features to house multiple experiments running in parallel, in particular with specific stages for sample environments to study slow kinetic systems or processes. The instrument benefits from a high-brightness X-ray beam and a large area detector. Diffraction data from the commissioning work have shown that the objectives and criteria are met. Supported by two case studies, the results from months of measurements have demonstrated the viability of this large-scale instrument, which is the world’s first dedicated facility for long-term studies (weeks to years) using synchrotron radiation. PMID:28190992

Three-dimensional monochromatic x-ray computed tomography using synchrotron radiation

NASA Astrophysics Data System (ADS)

Saito, Tsuneo; Kudo, Hiroyuki; Takeda, Tohoru; Itai, Yuji; Tokumori, Kenji; Toyofuku, Fukai; Hyodo, Kazuyuki; Ando, Masami; Nishimura, Katsuyuki; Uyama, Chikao

1998-08-01

We describe a technique of 3D computed tomography (3D CT) using monochromatic x rays generated by synchrotron radiation, which performs a direct reconstruction of a 3D volume image of an object from its cone-beam projections. For the development, we propose a practical scanning orbit of the x-ray source to obtain complete 3D information on an object, and its corresponding 3D image reconstruction algorithm. The validity and usefulness of the proposed scanning orbit and reconstruction algorithm were confirmed by computer simulation studies. Based on these investigations, we have developed a prototype 3D monochromatic x-ray CT using synchrotron radiation, which provides exact 3D reconstruction and material-selective imaging by using the K-edge energy subtraction technique.

The synchrotron-self-Compton process in spherical geometries. I - Theoretical framework

NASA Technical Reports Server (NTRS)

Band, D. L.; Grindlay, J. E.

1985-01-01

Both spatial and spectral accuracies are stressed in the present method for the calculation of the synchrotron-self-Compton model in spherical geometries, especially in the partially opaque regime of the synchrotron spectrum of inhomogeneous sources that can span a few frequency decades and contribute a significant portion of the scattered flux. A formalism is developed that permits accurate calculation of incident photon density throughout an optically thin sphere. An approximation to the Klein-Nishina cross section is used to model the effects of variable electron and incident photon cutoffs, as well as the decrease in the cross section at high energies. General results are derived for the case of inhomogeneous sources with power law profiles in both electron density and magnetic field.

Mixed Dimensional Van der Waals Heterostructures for Opto-Electronics.

NASA Astrophysics Data System (ADS)

Jariwala, Deep

The isolation of a growing number of two-dimensional (2D) materials has inspired worldwide efforts to integrate distinct 2D materials into van der Waals (vdW) heterostructures. While a tremendous amount of research activity has occurred in assembling disparate 2D materials into ``all-2D'' van der Waals heterostructures, this concept is not limited to 2D materials alone. Given that any passivated, dangling bond-free surface will interact with another via vdW forces, the vdW heterostructure concept can be extended to include the integration of 2D materials with non-2D materials that adhere primarily through noncovalent interactions. In the first part of this talk I will present our work on emerging mixed-dimensional (2D + nD, where n is 0, 1 or 3) heterostructure devices performed at Northwestern University. I will present two distinct examples of gate-tunable p-n heterojunctions 1. Single layer n-type MoS2\\ (2D) combined with p-type semiconducting single walled carbon nanotubes (1D) and 2. Single layer MoS2 combined with 0D molecular semiconductor, pentacene. I will present the unique electrical properties, underlying charge transport mechanisms and photocurrent responses in both the above systems using a variety of scanning probe microscopy techniques as well as computational analysis. This work shows that van der Waals interactions are robust across different dimensionalities of materials and can allow fabrication of semiconductor devices with unique geometries and properties unforeseen in bulk semiconductors. Finally, I will briefly discuss our recent work from Caltech on near-unity absorption in atomically-thin photovoltaic devices. This work is supported by the Materials Research Center at Northwestern University, funded by the National Science Foundation (NSF DMR-1121262) and the Resnick Sustainability Institute at Caltech.

HUBBLE AND KECK DISCOVER GALAXY BUILDING BLOCK

NASA Technical Reports Server (NTRS)

2002-01-01

This NASA Hubble Space Telescope image shows a very small, faint galaxy 'building block' newly discovered by a unique collaboration between ground- and space-based telescopes. Hubble and the 10-meter Keck Telescopes in Hawaii joined forces, using a galaxy cluster which acts as gravitational lens to detect what scientists believe is one of the smallest very distant objects ever found. The galaxy cluster Abell 2218 was used by a team of European and American astronomers led by Richard Ellis (Caltech) in their systematic search for intrinsically faint distant star-forming systems. Without help from Abell 2218's exceptional magnifying power to make objects appear about 30 times brighter, the galaxy building block would have been undetectable. In the image to the right, the object is seen distorted into two nearly identical, very red 'images' by the gravitational lens. The image pair represents the magnified result of a single background object gravitationally lensed by Abell 2218 and viewed at a distance of 13.4 billion light-years. The intriguing object contains only one million stars, far fewer than a mature galaxy, and scientists believe it is very young. Such young star-forming systems of low mass at early cosmic times are likely to be the objects from which present-day galaxies have formed. In the image to the left, the full overview of the galaxy cluster Abell 2218 is seen. This image was taken by Hubble in 1999 at the completion of Hubble Servicing Mission 3A. Credit: NASA, ESA, Richard Ellis (Caltech) and Jean-Paul Kneib (Observatoire Midi-Pyrenees, France) Acknowledgment: NASA, A. Fruchter and the ERO Team (STScI and ST-ECF)

EVN observations of eleven GHz-Peaked-Spectrum radio sources at 2.3/8.4 GHz

NASA Astrophysics Data System (ADS)

Xiang, L.; Dallacasa, D.; Cassaro, P.; Jiang, D.; Reynolds, C.

2005-04-01

We present results of EVN observations of eleven GHz-Peaked-Spectrum (GPS) radio sources at 2.3/8.4 GHz. These sources are from the classical "bright" GPS source samples with peak flux densities > 0.2 Jy and spectral indices α < -0.2 (S ∝ ν-α) in the optically thick regime of their convex spectra. Most of the target sources did not have VLBI images at the time this project started. The aim of the work is to find Compact Symmetric Object (CSO) candidates from the "bright" GPS samples. These CSOs play a key role in understanding the very early stage of the evolution of individual radio galaxies. The reason for investigating GPS source samples is that CSO candidates are more frequently found among this class of radio sources. In fact both classes, GPS and CSO, represent a small fraction of the flux limited and flat-spectrum samples like PR+CJ1 (PR: Pearson-Readhead survey, CJ1: the first Caltech-Jodrell Bank survey) and CJF (the Caltech-Jodrell Bank flat spectrum source survey) with a single digit percentage progressively decreasing with decreasing flux density limit. Our results, with at least 3, but possibly more CSO sources detected among a sample of 11, underline the effectiveness of our approach. The three confirmed CSO sources (1133+432, 1824+271, and 2121-014) are characterized by a symmetric pair of resolved components, each with steep spectral indices. Five further sources (0144+209, 0554-026, 0904+039, 0914+114 and 2322-040) can be considered likely CSO candidates. The remaining three sources (0159+839, 0602+780 and 0802+212) are either of core-jet type or dominated by a single component at both frequencies.

The NuSTAR Education and Public Outreach Program

NASA Astrophysics Data System (ADS)

Cominsky, Lynn R.; McLin, K. M.; NuSTAR Team

2010-01-01

The Nuclear Spectroscopic Telescope Array (NuSTAR) is a NASA Small Explorer mission led by Caltech, managed by JPL, and implemented by an international team of scientists and engineers, under the direction of CalTech Professor Fiona Harrison, principal investigator. NuSTAR is a pathfinder mission that will open the high-energy X-ray sky for sensitive study for the first time. By focusing X-rays at higher energies (up to 79 keV) NuSTAR will answer fundamental questions about the Universe: How are black holes distributed through the cosmos? How were the elements that compose our bodies and the Earth forged in the explosions of massive stars? What powers the most extreme active galaxies? Perhaps most exciting is the opportunity to fill a blank map with wonders we have not yet dreamed of: NuSTAR offers the opportunity to explore our Universe in an entirely new way. The purpose of the NuSTAR E/PO program is to increase student and public understanding of the science of the high-energy Universe, by capitalizing on the synergy of existing high-energy astrophysics E/PO programs to support the mission's objectives. Our goals are to: facilitate understanding of the nature of collapsed objects, develop awareness of the role of supernovae in creating the chemical elements and to facilitate understanding of the physical properties of the extreme Universe. We will do this through a program that includes educator workshops through NASA's Astrophysics Educator Ambassador program, by writing articles for Physics Teacher and Science Scope magazines to reach a broader community of educators, and by working with informal educators through museums and planetaria to develop an exhibit that includes a model of NuSTAR and describes the mission's science objectives. We will also develop printed materials such as a mission factsheet that describes the mission.

The NuSTAR Education and Public Outreach Program

NASA Astrophysics Data System (ADS)

Cominsky, Lynn R.; McLin, K. M.; NuSTAR Team

2010-03-01

NuSTAR is a NASA Small Explorer mission led by Caltech, managed by JPL, and implemented by an international team of scientists and engineers, under the direction of CalTech Professor Fiona Harrison, principal investigator. NuSTAR is a pathfinder mission that will open the high-energy X-ray sky for sensitive study for the first time. By focusing X-rays at higher energies (up to 79 keV) NuSTAR will answer fundamental questions about the Universe: How are black holes distributed through the cosmos? How were the elements that compose our bodies and the Earth forged in the explosions of massive stars? What powers the most extreme active galaxies? Perhaps most exciting is the opportunity to fill a blank map with wonders we have not yet dreamed of: NuSTAR offers the opportunity to explore our Universe in an entirely new way. The purpose of the NuSTAR E/PO program is to increase student and public understanding of the science of the high-energy Universe, by capitalizing on the synergy of existing high-energy astrophysics E/PO programs to support the mission's objectives. Our goals are to: facilitate understanding of the nature of collapsed objects, develop awareness of the role of supernovae in creating the chemical elements and to facilitate understanding of the physical properties of the extreme Universe. We will do this through a program that includes educator workshops through NASA's Astrophysics Educator Ambassador program, by writing articles for Physics Teacher and Science Scope magazines to reach a broader community of educators, and by working with informal educators through museums and planetaria to develop an exhibit that includes a model of NuSTAR and describes the mission's science objectives. We will also develop printed materials such as a mission factsheet that describes the mission.

Solar System Studies with the Space Infrared Telescope Facility (SIRTF)

NASA Technical Reports Server (NTRS)

Cruikshank, Dale P.; DeVincenzi, Donald L. (Technical Monitor)

1998-01-01

SIRTF (Space Infrared Telescope Facility) is the final element in NASA's 'Great Observatories' program. It consists of an 85-cm cryogenically-cooled observatory for infrared astronomy from space. SIRTF is scheduled for launch in late 2001 or early 2002 on a Delta rocket into a heliocentric orbit trailing the Earth. Data from SIRTF will be processed and disseminated to the community through the SIRTF Science Center (SSC) located at the Infrared Processing and Analysis Center (IPAC) at Caltech. Some 80/% of the total observing time (estimated at a minimum of 7500 hours of integration time per year for the mission lifetime of about 4 years) will be available to the scientific community at large through a system of refereed proposals. Three basic instruments are located in the SIRTF focal plane. The Multiband Imaging Photometer (MIPS), the Infrared Array Camera (IRAC), and the Infrared Spectrometer (IRS), taken together, provide imaging and spectroscopy from 3.5 to 160 microns. Among the solar system studies suited to SIRTF are the following: 1) spectroscopy and radiometry of small bodies from the asteroid main belt, through the Trojan clouds, to the Kuiper Disk; 2) dust distribution in the zodiacal cloud and the Earth's heliocentric dust ring; 3) spectroscopy and radiometry of comets; and 4) spectroscopy and radiometry of planets and their satellites. Searches for, and studies of dust disks around other stars, brown dwarfs, and superplanets will also be conducted with SIRTF. The SORTIE web site (http://ssc.ipac.caltech.edu/sirtf) contains important details and documentation on the project, the spacecraft, the telescope, instruments, and observing procedures. A community-wide workshop for solar system studies with SIRTF is in the planning stages by the author and Martha S. Hanner for the summer of 1999.

Night OH In The Mesosphere Of Venus and Earth: A Comparative Planetology Perspective

NASA Astrophysics Data System (ADS)

Parkinson, Chris; Brecht, A.; Bougher, S.; Mills, F.; Yung, Y.

2009-09-01

Satellite measurements of the terrestrial nightside mesosphere from the MLS/Aura MLS instrument show a layer of OH near 82 km. This layer confirms earlier measurements by ground-based UVFTS. The MLS and UVFTS observations measure OH in the lowest vibrational state and are distinct, but related chemically, from vibrationally-excited emission from the OH Meinel bands in the near infrared. The Caltech 1-D KINETICS model has been extended to include vibrational dependence of OH reactions and shows good agreement with MLS OH data and with observations of the Meinel bands. The model shows a chemical lifetime of HOx that increases from less than a day at 80 km to over a month at 87 km. Above this altitude transport processes become an important part of HOx chemistry. The model predicts that ground state OH represents 99% of the total OH up to 84 km. Similarly, Venus airglow emissions detected at wave-lengths of 1.40-1.49 and 2.6-3.14 μm in limb obser-vations by the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) on the Venus Express space-craft are attributed to the OH (2-0) and (1-0) Meinel band transitions as well. The integrated emission rates for the OH (2-0) and (1-0) bands were measured to be 100±40 and 880±90 kR respectively, both peaking at an altitude of 96±2 km near midnight local time for the considered orbit. We use the same Caltech 1-D KINETICS model to model these observations for Venus as was used for the Earth and discuss the conclusions from a comparative planetology perspective, highlighting the similarities and differences between Venus and Earth.

The role of iron in neurodegenerative disorders: insights and opportunities with synchrotron light

PubMed Central

Collingwood, Joanna F.; Davidson, Mark R.

2014-01-01

There is evidence for iron dysregulation in many forms of disease, including a broad spectrum of neurodegenerative disorders. In order to advance our understanding of the pathophysiological role of iron, it is helpful to be able to determine in detail the distribution of iron as it relates to metabolites, proteins, cells, and tissues, the chemical state and local environment of iron, and its relationship with other metal elements. Synchrotron light sources, providing primarily X-ray beams accompanied by access to longer wavelengths such as infra-red, are an outstanding tool for multi-modal non-destructive analysis of iron in these systems. The micro- and nano-focused X-ray beams that are generated at synchrotron facilities enable measurement of iron and other transition metal elements to be performed with outstanding analytic sensitivity and specificity. Recent developments have increased the scope for methods such as X-ray fluorescence mapping to be used quantitatively rather than semi-quantitatively. Burgeoning interest, coupled with technical advances and beamline development at synchrotron facilities, has led to substantial improvements in resources and methodologies in the field over the past decade. In this paper we will consider how the field has evolved with regard to the study of iron in proteins, cells, and brain tissue, and identify challenges in sample preparation and analysis. Selected examples will be used to illustrate the contribution, and future potential, of synchrotron X-ray analysis for the characterization of iron in model systems exhibiting iron dysregulation, and for human cases of neurodegenerative disorders including Alzheimer’s disease, Parkinson’s disease, Friedreich’s ataxia, and amyotrophic lateral sclerosis. PMID:25191270

Non-destructive trace element microanalysis of as-received cometary nucleus samples using synchrotron x ray fluorescence

NASA Technical Reports Server (NTRS)

Sutton, S. R.

1989-01-01

The Synchrotron X ray Fluorescence (SXRF) microprobe at the National Synchrotron Light Source (NSLS), Brookhaven National Laboratory, will be an excellent instrument for non-destructive trace element analyses of cometary nucleus samples. Trace element analyses of as-received cometary nucleus material will also be possible with this technique. Bulk analysis of relatively volatile elements will be important in establishing comet formation conditions. However, as demonstrated for meteorites, microanalyses of individual phases in their petrographic context are crucial in defining the histories of particular components in unequilibrated specimens. Perhaps most informative in comparing cometary material with meteorites will be the halogens and trace metals. In-situ, high spatial resolution microanalyses will be essential in establishing host phases for these elements and identifying terrestrial (collection/processing) overprints. The present SXRF microprobe is a simple, yet powerful, instrument in which specimens are excited with filtered, continuum synchrotron radiation from a bending magnet on a 2.5 GeV electron storage ring. A refrigerated cell will be constructed to permit analyses at low temperatures. The cell will consist essentially of an air tight housing with a cold stage. Kapton windows will be used to allow the incident synchrotron beam to enter the cell and fluorescent x rays to exit it. The cell will be either under vacuum or continuous purge by ultrapure helium during analyses. Several other improvements of the NSLS microprobe will be made prior to the cometary nucleus sample return mission that will greatly enhance the sensitivity of the technique.

The behavior of beams of relativistic non-thermal electrons under the influence of collisions and synchrotron losses

NASA Technical Reports Server (NTRS)

Mctiernan, James M.; Petrosian, Vahe

1989-01-01

For many astrophysical situations, such as in solar flares or cosmic gamma-ray bursts, continuum gamma rays with energies up to hundreds of MeV were observed, and can be interpreted to be due to bremsstrahlung radiation by relativistic electrons. The region of acceleration for these particles is not necessarily the same as the region in which the radiation is produced, and the effects of the transport of the electrons must be included in the general problem. Hence it is necessary to solve the kinetic equation for relativistic electrons, including all the interactions and loss mechanisms relevant at such energies. The resulting kinetic equation for non-thermal electrons, including the effects of Coulomb collisions and losses due to synchrotron emission, was solved analytically in some simple limiting cases, and numerically for the general cases including constant and varying background plasma density and magnetic field. New approximate analytic solutions are presented for collision dominated cases, for small pitch angles and all energies, synchrotron dominated cases, both steady-state and time dependent, for all pitch angles and energies, and for cases when both synchrotron and collisional energy losses are important, but for relativistic electrons. These analytic solutions are compared to the full numerical results in the proper limits. These results will be useful for calculation of spectra and angular distribution of the radiation (x rays, gamma-rays, and microwaves) emitted via synchrotron or bremsstrahlung processes by the electrons. These properties and their relevance to observations will be observed in subsequent papers.

γ-Ray And Parsec-Scale Jet Properties Of A Complete Sample Of Blazars From The Mojave Program

DOE PAGES

Lister, M. L.

2011-11-02

We investigate the Fermi LAT -ray and 15 GHz VLBA radio properties of a joint -ray- and radio-selected sample of AGNs obtained during the first 11 months of the Fermi mission (2008 Aug 4 - 2009 Jul 5). Our sample contains the brightest 173 AGNs in these bands above declination -30° during this period, and thus probes the full range of -ray loudness ( -ray to radio band luminosity ratio) in the bright blazar population. The latter quantity spans at least four orders ofmagnitude, reflecting a wide range of spectral energy distribution (SED) parameters in the bright blazar population. Themore » BL Lac objects, however, display a linear correlation of increasing -ray loudness with synchrotron SED peak frequency, suggesting a universal SED shape for objects of this class. The synchrotron self-Compton model is favored for the -ray emission in these BL Lacs over external seed photon models, since the latter predict a dependence of Compton dominance on Doppler factor that would destroy any observed synchrotron SED peak - -ray loudness correlation. The high-synchrotron peaked (HSP) BL Lac objects are distinguished by lower than average radio core brightness temperatures, and none display large radio modulation indices or high linear core polarization levels. No equivalent trends are seen for the flat-spectrum radio quasars (FSRQ) in our sample. Given the association of such properties with relativistic beaming, we suggest that the HSP BL Lacs have generally lower Doppler factors than the lower-synchrotron peaked BL Lacs or FSRQs in our sample.« less

Gamma-Ray and Parsec-Scale Jet Properties of a Complete Sample of Blazars from the MOJAVE Program

NASA Technical Reports Server (NTRS)

Lister, M.L.; Aller, M.; Aller, H.; Hovatta, T.; Kellermann, K. I.; Kovalev, Y. Y.; Meyer, E. T.; Pushkarev, A. B.; Ros, E.; Ackermann, M.;

6th International Conference on Biophysics & Synchrotron Radiation. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moffat, Keith

1999-08-03

The 6th International Conference on Biophysics and Synchrotron Rdiation was held at the Advanced Photon Source, Argonne National Laboratory, from August 4-8, 1998, with pre-conference activities on August 3. Over 300 attendees and 65 presenters participated in the conference that was collaboratively hosted by the University of Chicago, Center for Advanced Radiation Sources and the Advanced Photon Source.

X-ray and synchrotron methods in studies of cultural heritage sites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koval’chuk, M. V.; Yatsishina, E. B.; Blagov, A. E.

2016-09-15

X-ray and synchrotron methods that are most widely used in studies of cultural heritage objects (including archaeological sites)—X-ray diffraction analysis, X-ray spectroscopy, and visualization techniques— have been considered. The reported examples show high efficiency and informativeness of natural science studies when solving most diverse problems of archaeology, history, the study of art, museology, etc.

Synchrotron x-ray modification of nanoparticle superlattice formation

NASA Astrophysics Data System (ADS)

Lu, Chenguang; Akey, Austin J.; Herman, Irving P.

2012-09-01

The synchrotron x-ray radiation used to perform small angle x-ray scattering (SAXS) during the formation of three-dimensional nanoparticle superlattices by drop casting nanoparticle solutions affects the structure and the local crystalline order of the resulting films. The domain size decreases due to the real-time SAXS analysis during drying and more macroscopic changes are visible to the eye.

X-Ray Data Booklet

Science.gov Websites

X-RAY DATA BOOKLET Center for X-ray Optics and Advanced Light Source Lawrence Berkeley National Laboratory Introduction X-Ray Properties of Elements Electron Binding Energies X-Ray Energy Emission Energies Table of X-Ray Properties Synchrotron Radiation Characteristics of Synchrotron Radiation History of X

Synchrotron-based X-ray Fluorescence Microscopy in Conjunction with Nanoindentation to Study Molecular-Scale Interactions of Phenol–Formaldehyde in Wood Cell Walls

Treesearch

Joseph E. Jakes; Christopher G. Hunt; Daniel J. Yelle; Linda Lorenz; Kolby Hirth; Sophie-Charlotte Gleber; Stefan Vogt; Warren Grigsby; Charles R. Frihart

2015-01-01

Understanding and controlling molecular-scale interactions between adhesives and wood polymers are critical to accelerate the development of improved adhesives for advanced wood-based materials. The submicrometer resolution of synchrotron-based X-ray fluorescence microscopy (XFM) was found capable of mapping and quantifying infiltration of Br-labeled phenol−...

Using Synchrotron Radiation Microtomography to Investigate Multi-scale Three-dimensional Microelectronic Packages

DOE PAGES

Carlton, Holly D.; Elmer, John W.; Li, Yan; ...

2016-04-13

For this study synchrotron radiation micro-­tomography, a non-destructive three-dimensional imaging technique, is employed to investigate an entire microelectronic package with a cross-sectional area of 16 x 16 mm. Due to the synchrotron’s high flux and brightness the sample was imaged in just 3 minutes with an 8.7 μm spatial resolution.

National Synchrotron Light Source

ScienceCinema

BNL

2017-12-09

A tour of Brookhaven's National Synchrotron Light Source (NSLS), hosted by Associate Laboratory Director for Light Sources, Stephen Dierker. The NSLS is one of the world's most widely used scientific research facilities, hosting more than 2,500 guest researchers each year. The NSLS provides intense beams of infrared, ultraviolet, and x-ray light for basic and applied research in physics, chemistry, medicine, geophysics, environmental, and materials sciences.

Nsls-II Boster

NASA Astrophysics Data System (ADS)

Gurov, S. M.; Akimov, A. V.; Akimov, V. E.; Anashin, V. V.; Anchugov, O. V.; Baranov, G. N.; Batrakov, A. M.; Belikov, O. V.; Bekhtenev, E. A.; Blum, E.; Bulatov, A. V.; Burenkov, D. B.; Cheblakov, P. B.; Chernyakin, A. D.; Cheskidov, V. G.; Churkin, I. N.; Davidsavier, M.; Derbenev, A. A.; Erokhin, A. I.; Fliller, R. P.; Fulkerson, M.; Gorchakov, K. M.; Ganetis, G.; Gao, F.; Gurov, D. S.; Hseuh, H.; Hu, Y.; Johanson, M.; Kadyrov, R. A.; Karnaev, S. E.; Karpov, G. V.; Kiselev, V. A.; Kobets, V. V.; Konstantinov, V. M.; Kolmogorov, V. V.; Korepanov, A. A.; Kramer, S.; Krasnov, A. A.; Kremnev, A. A.; Kuper, E. A.; Kuzminykh, V. S.; Levichev, E. B.; Li, Y.; Long, J. De; Makeev, A. V.; Mamkin, V. R.; Medvedko, A. S.; Meshkov, O. I.; Nefedov, N. B.; Neyfeld, V. V.; Okunev, I. N.; Ozaki, S.; Padrazo, D.; Petrov, V. V.; Petrichenkov, M. V.; Philipchenko, A. V.; Polyansky, A. V.; Pureskin, D. N.; Rakhimov, A. R.; Rose, J.; Ruvinskiy, S. I.; Rybitskaya, T. V.; Sazonov, N. V.; Schegolev, L. M.; Semenov, A. M.; Semenov, E. P.; Senkov, D. V.; Serdakov, L. E.; Serednyakov, S. S.; Shaftan, T. V.; Sharma, S.; Shichkov, D. S.; Shiyankov, S. V.; Shvedov, D. A.; Simonov, E. A.; Singh, O.; Sinyatkin, S. V.; Smaluk, V. V.; Sukhanov, A. V.; Tian, Y.; Tsukanova, L. A.; Vakhrushev, R. V.; Vobly, P. D.; Utkin, A. V.; Wang, G.; Wahl, W.; Willeke, F.; Yaminov, K. R.; Yong, H.; Zhuravlev, A.; Zuhoski, P.

The National Synchrotron Light Source II is a third generation light source, which was constructed at Brookhaven National Laboratory. This project includes a highly-optimized 3 GeV electron storage ring, linac preinjector, and full-energy synchrotron injector. Budker Institute of Nuclear Physics built and delivered the booster for NSLS-II. The commissioning of the booster was successfully completed. This paper reviews fulfilled work by participants.

Current advances in synchrotron radiation instrumentation for MX experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Owen, Robin L.; Juanhuix, Jordi; Fuchs, Martin

2016-07-01

Following pioneering work 40 years ago, synchrotron beamlines dedicated to macromolecular crystallography (MX) have improved in almost every aspect as instrumentation has evolved. Beam sizes and crystal dimensions are now on the single micron scale while data can be collected from proteins with molecular weights over 10 MDa and from crystals with unit cell dimensions over 1000 Å. Furthermore it is possible to collect a complete data set in seconds, and obtain the resulting structure in minutes. The impact of MX synchrotron beamlines and their evolution is reflected in their scientific output, and MX is now the method of choicemore » for a variety of aims from ligand binding to structure determination of membrane proteins, viruses and ribosomes, resulting in a much deeper understanding of the machinery of life. A main driving force of beamline evolution have been advances in almost every aspect of the instrumentation comprising a synchrotron beamline. In this review we aim to provide an overview of the current status of instrumentation at modern MX experiments. The most critical optical components are discussed, as are aspects of endstation design, sample delivery, visualisation and positioning, the sample environment, beam shaping, detectors and data acquisition and processing.« less

Current advances in synchrotron radiation instrumentation for MX experiments.

PubMed

Owen, Robin L; Juanhuix, Jordi; Fuchs, Martin

2016-07-15

Following pioneering work 40 years ago, synchrotron beamlines dedicated to macromolecular crystallography (MX) have improved in almost every aspect as instrumentation has evolved. Beam sizes and crystal dimensions are now on the single micron scale while data can be collected from proteins with molecular weights over 10 MDa and from crystals with unit cell dimensions over 1000 Å. Furthermore it is possible to collect a complete data set in seconds, and obtain the resulting structure in minutes. The impact of MX synchrotron beamlines and their evolution is reflected in their scientific output, and MX is now the method of choice for a variety of aims from ligand binding to structure determination of membrane proteins, viruses and ribosomes, resulting in a much deeper understanding of the machinery of life. A main driving force of beamline evolution have been advances in almost every aspect of the instrumentation comprising a synchrotron beamline. In this review we aim to provide an overview of the current status of instrumentation at modern MX experiments. The most critical optical components are discussed, as are aspects of endstation design, sample delivery, visualisation and positioning, the sample environment, beam shaping, detectors and data acquisition and processing. Copyright © 2016. Published by Elsevier Inc.

ALICE—An advanced reflectometer for static and dynamic experiments in magnetism at synchrotron radiation facilities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abrudan, R.; Helmholtz-Zentrum-Berlin for Materials and Energy, 12489 Berlin; Brüssing, F.

2015-06-15

We report on significant developments of a high vacuum reflectometer (diffractometer) and spectrometer for soft x-ray synchrotron experiments which allows conducting a wide range of static and dynamic experiments. Although the chamber named ALICE was designed for the analysis of magnetic hetero- and nanostructures via resonant magnetic x-ray scattering, the instrument is not limited to this technique. The versatility of the instrument was testified by a series of pilot experiments. Static measurements involve the possibility to use scattering and spectroscopy synchrotron based techniques (photon-in photon-out, photon-in electron-out, and coherent scattering). Dynamic experiments require either laser or magnetic field pulses tomore » excite the spin system followed by x-ray probe in the time domain from nano- to femtosecond delay times. In this temporal range, the demagnetization/remagnetization dynamics and magnetization precession in a number of magnetic materials (metals, alloys, and magnetic multilayers) can be probed in an element specific manner. We demonstrate here the capabilities of the system to host a variety of experiments, featuring ALICE as one of the most versatile and demanded instruments at the Helmholtz Center in Berlin-BESSY II synchrotron center in Berlin, Germany.« less

Bio-metals imaging and speciation in cells using proton and synchrotron radiation X-ray microspectroscopy

PubMed Central

Ortega, Richard; Devès, Guillaume; Carmona, Asunción

2009-01-01

The direct detection of biologically relevant metals in single cells and of their speciation is a challenging task that requires sophisticated analytical developments. The aim of this article is to present the recent achievements in the field of cellular chemical element imaging, and direct speciation analysis, using proton and synchrotron radiation X-ray micro- and nano-analysis. The recent improvements in focusing optics for MeV-accelerated particles and keV X-rays allow application to chemical element analysis in subcellular compartments. The imaging and quantification of trace elements in single cells can be obtained using particle-induced X-ray emission (PIXE). The combination of PIXE with backscattering spectrometry and scanning transmission ion microscopy provides a high accuracy in elemental quantification of cellular organelles. On the other hand, synchrotron radiation X-ray fluorescence provides chemical element imaging with less than 100 nm spatial resolution. Moreover, synchrotron radiation offers the unique capability of spatially resolved chemical speciation using micro-X-ray absorption spectroscopy. The potential of these methods in biomedical investigations will be illustrated with examples of application in the fields of cellular toxicology, and pharmacology, bio-metals and metal-based nano-particles. PMID:19605403

Synchrotron based planar imaging and digital tomosynthesis of breast and biopsy phantoms using a CMOS active pixel sensor.

PubMed

Szafraniec, Magdalena B; Konstantinidis, Anastasios C; Tromba, Giuliana; Dreossi, Diego; Vecchio, Sara; Rigon, Luigi; Sodini, Nicola; Naday, Steve; Gunn, Spencer; McArthur, Alan; Olivo, Alessandro

2015-03-01

The SYRMEP (SYnchrotron Radiation for MEdical Physics) beamline at Elettra is performing the first mammography study on human patients using free-space propagation phase contrast imaging. The stricter spatial resolution requirements of this method currently force the use of conventional films or specialized computed radiography (CR) systems. This also prevents the implementation of three-dimensional (3D) approaches. This paper explores the use of an X-ray detector based on complementary metal-oxide-semiconductor (CMOS) active pixel sensor (APS) technology as a possible alternative, for acquisitions both in planar and tomosynthesis geometry. Results indicate higher quality of the images acquired with the synchrotron set-up in both geometries. This improvement can be partly ascribed to the use of parallel, collimated and monochromatic synchrotron radiation (resulting in scatter rejection, no penumbra-induced blurring and optimized X-ray energy), and partly to phase contrast effects. Even though the pixel size of the used detector is still too large - and thus suboptimal - for free-space propagation phase contrast imaging, a degree of phase-induced edge enhancement can clearly be observed in the images. Copyright © 2014 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Current advances in synchrotron radiation instrumentation for MX experiments

PubMed Central

Owen, Robin L.; Juanhuix, Jordi; Fuchs, Martin

2017-01-01

Following pioneering work 40 years ago, synchrotron beamlines dedicated to macromolecular crystallography (MX) have improved in almost every aspect as instrumentation has evolved. Beam sizes and crystal dimensions are now on the single micron scale while data can be collected from proteins with molecular weights over 10 MDa and from crystals with unit cell dimensions over 1000 Å. Furthermore it is possible to collect a complete data set in seconds, and obtain the resulting structure in minutes. The impact of MX synchrotron beamlines and their evolution is reflected in their scientific output, and MX is now the method of choice for a variety of aims from ligand binding to structure determination of membrane proteins, viruses and ribosomes, resulting in a much deeper understanding of the machinery of life. A main driving force of beamline evolution have been advances in almost every aspect of the instrumentation comprising a synchrotron beamline. In this review we aim to provide an overview of the current status of instrumentation at modern MX experiments. The most critical optical components are discussed, as are aspects of endstation design, sample delivery, visualization and positioning, the sample environment, beam shaping, detectors and data acquisition and processing. PMID:27046341

The influence of the ionized medium on synchrotron emission in interstellar space.

NASA Technical Reports Server (NTRS)

Ramaty, R.

1972-01-01

The effect of the ionized gas on synchrotron emission in the interstellar medium is investigated. A detailed calculation of the synchrotron emissivity of cosmic electrons, assumed to have an isotropic pitch-angle distribution in a uniform magnetic field, is made as a function of frequency and observation angle with respect to the field. The results are presented both as a local emissivity and as an intensity, the latter obtained by neglecting free-free absorption in the interstellar medium and by assuming that the emissivity is constant along the line of sight. The comparison of these results with previous studies on the nature of the low-frequency turnover of the galactic nonthermal radio background reveals that, except if the component perpendicular to the line of sight of the interstellar magnetic field is small (less than 1 microgauss), or if the cosmic-ray electron spectrum is cut off at energies below a few hundred MeV, the suppression of synchrotron emission by the ambient electrons has in general a lesser effect than free-free absorption by these electrons, and that in some cases this suppression effect is almost entirely negligible.

Role of Synchrotron infra red microspectroscopy in studying epidermotropism of cutaneous T-cell lymphoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

El Bedewi, A.; El Anany, G; El Mofty, M

2010-01-01

The molecular mechanisms of epidermotropism in mycosis fungoides (MF) are not well understood to date. The aim of this study was to differentiate between epidermal and dermal lymphocytes within the skin of MF patients. This study was done on 10 MF patients with a mean age of 50 years diagnosed clinically in the Department of Dermatology, Cairo University, Egypt. A 6 mm biopsy was taken from each patient in order to confirm the diagnosis. Skin biopsies were cut, put on low e-slides and then stained with H&E. Further examination with Synchrotron infrared (IR) microspectroscopy was done in National Synchrotron Lightmore » Source - Brookhaven National Laboratory, New York, USA. Immunophenotyping using antibodies CD3, CD4, CD8, CD20 and CD30 was also done. Statistical analysis was done by Student's t-test and cluster analysis. Both epidermal and dermal lymphocytes were clustered separately. Also, Amide I and RNA and DNA within the lymphocytes were significantly different between the epidermis and the dermis. The biochemical analysis of protein, RNA and DNA with Synchrotron IR microspectroscopy is a promising tool for studying epidermotropism in cutaneous T-cell lymphoma.« less

Synchrotron X-ray diffraction study of the Ba{sub 1−x}SrSnO{sub 3} solid solution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prodjosantoso, Anti K., E-mail: Prodjosantoso@yahoo.com; Zhou, Qingdi; Kennedy, Brendan J.

At room temperature the sequence of phases with increasing amounts of strontium in the stannate perovskite system Ba{sub 1−x}SrSnO{sub 3} has been established from high resolution synchrotron X-ray powder diffraction. The observed sequence orthorhombic (Pbnm), orthorhombic (Ibmm), tetragonal (I4/mcm), and cubic (Pm3-bar m) is a consequence of the sequential introduction of cooperative tilting of the corner sharing SnO{sub 6} octahedra. The cell volume changes smoothly across the series with no obvious discontinuities associated with the phase transitions. - Graphical abstract: Portions of the synchrotron X-ray diffraction profiles (λ=0.82453 Å) from selected Ba{sub 1−x}Sr{sub x}SnO{sub 3} samples together with the resultsmore » of fitting by the Rietveld method. Highlights: ► Structures of the stannate perovskites Ba{sub 1−x}SrSnO{sub 3} refined from synchrotron XRD. ► The sequence Pm3-bar m→I4/mcm→Ibmm→Pbnm results from tilting of the octahedra. ► The tilting maintains optimal bonding of the cations seen from the BVS analysis.« less

Main functions, recent updates, and applications of Synchrotron Radiation Workshop code

NASA Astrophysics Data System (ADS)

Chubar, Oleg; Rakitin, Maksim; Chen-Wiegart, Yu-Chen Karen; Chu, Yong S.; Fluerasu, Andrei; Hidas, Dean; Wiegart, Lutz

2017-08-01

The paper presents an overview of the main functions and new application examples of the "Synchrotron Radiation Workshop" (SRW) code. SRW supports high-accuracy calculations of different types of synchrotron radiation, and simulations of propagation of fully-coherent radiation wavefronts, partially-coherent radiation from a finite-emittance electron beam of a storage ring source, and time-/frequency-dependent radiation pulses of a free-electron laser, through X-ray optical elements of a beamline. An extended library of physical-optics "propagators" for different types of reflective, refractive and diffractive X-ray optics with its typical imperfections, implemented in SRW, enable simulation of practically any X-ray beamline in a modern light source facility. The high accuracy of calculation methods used in SRW allows for multiple applications of this code, not only in the area of development of instruments and beamlines for new light source facilities, but also in areas such as electron beam diagnostics, commissioning and performance benchmarking of insertion devices and individual X-ray optical elements of beamlines. Applications of SRW in these areas, facilitating development and advanced commissioning of beamlines at the National Synchrotron Light Source II (NSLS-II), are described.

Current advances in synchrotron radiation instrumentation for MX experiments

DOE PAGES

Owen, Robin L.; Juanhuix, Jordi; Fuchs, Martin

2016-04-01

Following pioneering work 40 years ago, synchrotron beamlines dedicated to macromolecular crystallography (MX) have improved in almost every aspect as instrumentation has evolved. Beam sizes and crystal dimensions are now on the single micron scale while data can be collected from proteins with molecular weights over 10 MDa and from crystals with unit cell dimensions over 1000 Å. Moreover, it is possible to collect a complete data set in seconds, and obtain the resulting structure in minutes. The impact of MX synchrotron beamlines and their evolution is reflected in their scientific output, and MX is now the method of choicemore » for a variety of aims from ligand binding to structure determination of membrane proteins, viruses and ribosomes, resulting in a much deeper understanding of the machinery of life. One main driving force of beamline evolution have been advances in almost every aspect of the instrumentation comprising a synchrotron beamline. In this review we aim to provide an overview of the current status of instrumentation at modern MX experiments. Furthermore, we discuss the most critical optical components, aspects of endstation design, sample delivery, visualisation and positioning, the sample environment, beam shaping, detectors and data acquisition and processing.« less

Radiological implications of top-off operation at national synchrotron light source-II

NASA Astrophysics Data System (ADS)

Job, P. K.; Casey, W. R.

2011-08-01

High current and low emittance have been specified to achieve ultra high brightness in the third generation medium energy Synchrotron Radiation Sources. This leads to the electron beam lifetime limited by Touschek scattering, and after commissioning may settle in at as low as ∼3 h. It may well be less in the early days of operation. At the same time, the intensity stability specified by the user community for the synchrotron beam is 1% or better. Given the anticipated lifetime of the beam, incremental filling called top-off injection at intervals on the order of ∼1 min will be required to maintain this beam stability. It is judged to be impractical to make these incremental fills by closing the beam shutters at each injection. In addition, closing the front end beam shutters during each injection will adversely affect the stability of beamline optics due to thermal cycling. Hence the radiological consequences of injection with front end beam shutters open must be evaluated. This paper summarizes results of radiological analysis carried out for the proposed top-off injection at National Synchrotron Light Source-II (NSLS-II) with beam shutters open.

Synchrotron X-ray topographic study on nature of threading mixed dislocations in 4H–SiC crystals grown by PVT method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guo, Jianqiu; Yang, Yu; Wu, Fangzhen

Synchrotron X-ray Topography is a powerful technique to study defects structures particularly dislocation configurations in single crystals. Complementing this technique with geometrical and contrast analysis can enhance the efficiency of quantitatively characterizing defects. In this study, the use of Synchrotron White Beam X-ray Topography (SWBXT) to determine the line directions of threading dislocations in 4H–SiC axial slices (sample cut parallel to the growth axis from the boule) is demonstrated. This technique is based on the fact that the projected line directions of dislocations on different reflections are different. Another technique also discussed is the determination of the absolute Burgers vectorsmore » of threading mixed dislocations (TMDs) using Synchrotron Monochromatic Beam X-ray Topography (SMBXT). This technique utilizes the fact that the contrast from TMDs varies on SMBXT images as their Burgers vectors change. By comparing observed contrast with the contrast from threading dislocations provided by Ray Tracing Simulations, the Burgers vectors can be determined. Thereafter the distribution of TMDs with different Burgers vectors across the wafer is mapped and investigated.« less

Insights into the varnishes of historical musical instruments using synchrotron micro-analytical methods

NASA Astrophysics Data System (ADS)

Echard, J.-P.; Cotte, M.; Dooryhee, E.; Bertrand, L.

2008-07-01

Though ancient violins and other stringed instruments are often revered for the beauty of their varnishes, the varnishing techniques are not much known. In particular, very few detailed varnish analyses have been published so far. Since 2002, a research program at the Musée de la musique (Paris) is dedicated to a detailed description of varnishes on famous ancient musical instruments using a series of novel analytical methods. For the first time, results are presented on the study of the varnish from a late 16th century Venetian lute, using synchrotron micro-analytical methods. Identification of both organic and inorganic compounds distributed within the individual layers of a varnish microsample has been performed using spatially resolved synchrotron Fourier transform infrared microscopy. The univocal identification of the mineral phases is obtained through synchrotron powder X-ray diffraction. The materials identified may be of utmost importance to understand the varnishing process and its similarities with some painting techniques. In particular, the proteinaceous binding medium and the calcium sulfate components (bassanite and anhydrite) that have been identified in the lower layers of the varnish microsample could be related, to a certain extent, to the ground materials of earlier Italian paintings.

Application of synchrotron radiation computed microtomography for quantification of bone microstructure in human and rat bones

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parreiras Nogueira, Liebert; Barroso, Regina Cely; Pereira de Almeida, Andre

2012-05-17

This work aims to evaluate histomorphometric quantification by synchrotron radiation computed microto-mography in bones of human and rat specimens. Bones specimens are classified as normal and pathological (for human samples) and irradiated and non-irradiated samples (for rat ones). Human bones are specimens which were affected by some injury, or not. Rat bones are specimens which were irradiated, simulating radiotherapy procedures, or not. Images were obtained on SYRMEP beamline at the Elettra Synchrotron Laboratory in Trieste, Italy. The system generated 14 {mu}m tomographic images. The quantification of bone structures were performed directly by the 3D rendered images using a home-made software.more » Resolution yielded was excellent what facilitate quantification of bone microstructures.« less

Physics of compact nonthermal sources. III - Energetic considerations. [electron synchrotron radiation

NASA Technical Reports Server (NTRS)

Burbidge, G. R.; Jones, T. W.; Odell, S. L.

1974-01-01

The energy content of the compact incoherent electron-synchrotron sources 3C 84, 3C 120, 3C 273, 3C 279, 3C 454.3, CTA 102, 3C 446, PKS 2134+004, VRO 42.22.01 and OJ 287 is calculated on the assumption that the low-frequency turnovers in the radio spectrum are due to self-absorption and that the electron distribution is isotropic. The dependence of the source parameters on various modifications of the standard assumptions is determined. These involve relativistic motions, alternate explanations for the low-frequency turnover, proton-synchrotron radiation, and distance to the source. The canonical interpretation is found to be accurate in many respects; some of the difficulties and ways of dealing with them are discussed in detail.

Synchrotron radiation-induced contamination on LiF window: Characterization by Raman spectroscopy

NASA Astrophysics Data System (ADS)

Yadav, P. K.; Swami, M. K.

2016-05-01

Characterization of synchrotron induced contamination on optical elements and their cleaning are serious issues in beam lines. We used Raman spectroscopy for characterization of synchrotron induced contamination layer on LiF window (used in high resolution vacuum ultra violet beam line). Three peaks at 1035 cm-1 (corresponding to C-C sp3 vibrations), 1563 cm-1 and 1375 cm-1 (corresponding to G and D bands of carbon) are observed. By data fitting I(D)/I(G) ratio (0.84) and FWHM(G)=124 cm-1 was obtained. Comparison with available literature indicates that the carbon might be present in the form of rings of hydrogenated amorphous carbon a-C:H (GLHC) with atomic hydrogen concentration about 15% with both sp2 and sp3 hybridization.

Virtual dissection of Thoropa miliaris tadpole using phase-contrast synchrotron microtomography

NASA Astrophysics Data System (ADS)

Fidalgo, G.; Colaço, M. V.; Nogueira, L. P.; Braz, D.; Silva, H. R.; Colaço, G.; Barroso, R. C.

2018-05-01

In this work, in-line phase-contrast synchrotron microtomography was used in order to study the external and internal morphology of Thoropa miliaris tadpoles. Whole-specimens of T. miliaris in larval stages of development 28, 37 and 42, collected in the municipality of Mangaratiba (Rio de Janeiro, Brazil) were used for the study. The samples were scanned in microtomography beamline (IMX) at the Brazilian Synchrotron Light Laboratory (LNLS). The phase-contrast technique allowed us to obtain high quality images which made possible the structures segmentation on the rendered volume by the Avizo graphic image editing software. The combination of high quality images and segmentation process provides adequate visualization of different organs and soft (liver, notochord, brain, crystalline, cartilages) and hard (elements of the bone skeleton) tissues.

Time domain analysis of coherent terahertz synchrotron radiation

NASA Astrophysics Data System (ADS)

Hübers, H.-W.; Semenov, A.; Holldack, K.; Schade, U.; Wüstefeld, G.; Gol'tsman, G.

2005-10-01

The time structure of coherent terahertz synchrotron radiation at the electron storage ring of the Berliner Elektronensynchrotron und Speicherring Gesellschaft has been analyzed with a fast superconducting hot-electron bolometer. The emission from a single bunch of electrons was found to last ˜1500ps at frequencies around 0.4THz, which is much longer than the length of an electron bunch in the time domain (˜5ps). It is suggested that this is caused by multiple reflections at the walls of the beam line. The quadratic increase of the power with the number of electrons in the bunch as predicted for coherent synchrotron radiation and the transition from stable to bursting radiation were determined from a single storage ring fill pattern of bunches with different populations.

Radiation reaction and pitch-angle changes for a charge undergoing synchrotron losses

NASA Astrophysics Data System (ADS)

Singal, Ashok K.

2016-05-01

In the derivation of synchrotron radiation formulae, it has been assumed that the pitch angle of a charge remains constant during the radiation process. However, from the radiation reaction formula, while the component of the velocity vector perpendicular to the magnetic field reduces in magnitude due to radiative losses, the parallel component does not undergo any change during radiation. Therefore, there is a change in the ratio of the two components, implying a change in the pitch angle. We derive the exact formula for the change in energy of radiating electrons by taking into account the change of the pitch angle due to radiative losses. From this, we derive the characteristic decay time of synchrotron electrons over which they turn from highly relativistic into mildly relativistic ones.

Studies of LSO:Tb radio-luminescence properties using white beam hard X-ray synchrotron irradiation

NASA Astrophysics Data System (ADS)

Cecilia, A.; Rack, A.; Pelliccia, D.; Douissard, P.-A.; Martin, T.; Couchaud, M.; Dupré, K.; Baumbach, T.

A radio-luminescence set-up was installed at the synchrotron light source ANKA to characterise scintillators under the high X-ray photon flux density of white beam synchrotron radiation. The system allows for investigating the radio-luminescence spectrum of the material under study as well as analysing in situ changes of its scintillation behaviour (e.g. under heat load and/or intensive ionising radiation). In this work we applied the radio-luminescence set-up for investigating the radiation damage effects on the luminescence properties of a new kind of thin single crystal scintillator for high resolution X-ray imaging based on a layer of modified Lu2SiO5 grown by liquid phase epitaxy on a dedicated substrate within the framework of an EC project (SCINTAX).

Cosmic Rays and Their Radiative Processes in Numerical Cosmology

NASA Technical Reports Server (NTRS)

Ryu, Dongsu; Miniati, Francesco; Jones, Tom W.; Kang, Hyesung

2000-01-01

A cosmological hydrodynamic code is described, which includes a routine to compute cosmic ray acceleration and transport in a simplified way. The routine was designed to follow explicitly diffusive, acceleration at shocks, and second-order Fermi acceleration and adiabatic loss in smooth flows. Synchrotron cooling of the electron population can also be followed. The updated code is intended to be used to study the properties of nonthermal synchrotron emission and inverse Compton scattering from electron cosmic rays in clusters of galaxies, in addition to the properties of thermal bremsstrahlung emission from hot gas. The results of a test simulation using a grid of 128 (exp 3) cells are presented, where cosmic rays and magnetic field have been treated passively and synchrotron cooling of cosmic ray electrons has not been included.

Phase contrast portal imaging using synchrotron radiation

NASA Astrophysics Data System (ADS)

Umetani, K.; Kondoh, T.

2014-07-01

Microbeam radiation therapy is an experimental form of radiation treatment with great potential to improve the treatment of many types of cancer. We applied a synchrotron radiation phase contrast technique to portal imaging to improve targeting accuracy for microbeam radiation therapy in experiments using small animals. An X-ray imaging detector was installed 6.0 m downstream from an object to produce a high-contrast edge enhancement effect in propagation-based phase contrast imaging. Images of a mouse head sample were obtained using therapeutic white synchrotron radiation with a mean beam energy of 130 keV. Compared to conventional portal images, remarkably clear images of bones surrounding the cerebrum were acquired in an air environment for positioning brain lesions with respect to the skull structure without confusion with overlapping surface structures.

Methodological challenges of optical tweezers-based X-ray fluorescence imaging of biological model organisms at synchrotron facilities.

PubMed

Vergucht, Eva; Brans, Toon; Beunis, Filip; Garrevoet, Jan; Bauters, Stephen; De Rijcke, Maarten; Deruytter, David; Janssen, Colin; Riekel, Christian; Burghammer, Manfred; Vincze, Laszlo

2015-07-01

Recently, a radically new synchrotron radiation-based elemental imaging approach for the analysis of biological model organisms and single cells in their natural in vivo state was introduced. The methodology combines optical tweezers (OT) technology for non-contact laser-based sample manipulation with synchrotron radiation confocal X-ray fluorescence (XRF) microimaging for the first time at ESRF-ID13. The optical manipulation possibilities and limitations of biological model organisms, the OT setup developments for XRF imaging and the confocal XRF-related challenges are reported. In general, the applicability of the OT-based setup is extended with the aim of introducing the OT XRF methodology in all research fields where highly sensitive in vivo multi-elemental analysis is of relevance at the (sub)micrometre spatial resolution level.

Synchrotron X-ray fluorescence analyses of stratospheric cosmic dust - New results for chondritic and low-nickel particles

NASA Technical Reports Server (NTRS)

Flynn, G. J.; Sutton, S. R.

1990-01-01

Trace element abundance determinations were performed using synchrotron X-ray fluorescence on nine particles collected from the stratosphere and classified as cosmic. Improvements to the Synchrotron Light Source allowed the detection of all elements between Cr and Mo, with the exceptions of Co and As, in our largest particle. The minor and trace element abundance patterns of three Ni-depleted particles were remarkably similar to those of extraterrestrial igneous rocks. Fe/Ni and Fe/Mn ratios suggest that one of these may be of lunar origin. All nine particles exhibited an enrichment in Br, ranging from 1.3 to 38 times the C1 concentration. Br concentrations were uncorrelated with particle size, as would be expected for a surface correlated component acquires from the stratosphere.

Cosmic Rays and Their Radiative Processes in Numerical Cosmology

NASA Astrophysics Data System (ADS)

Ryu, D.; Miniati, F.; Jones, T. W.; Kang, H.

2000-05-01

A cosmological hydrodynamic code is described, which includes a routine to compute cosmic ray acceleration and transport in a simplified way. The routine was designed to follow explicitly diffusive acceleration at shocks, and second-order Fermi acceleration and adiabatic loss in smooth flows. Synchrotron cooling of the electron population can also be followed. The updated code is intended to be used to study the properties of nonthermal synchrotron emission and inverse Compton scattering from electron cosmic rays in clusters of galaxies, in addition to the properties of thermal bremsstrahlung emission from hot gas. The results of a test simulation using a grid of 1283 cells are presented, where cosmic rays and magnetic field have been treated passively and synchrotron cooling of cosmic ray electrons has not been included.

Experimental studies of systematic multiple-energy operation at HIMAC synchrotron

NASA Astrophysics Data System (ADS)

Mizushima, K.; Katagiri, K.; Iwata, Y.; Furukawa, T.; Fujimoto, T.; Sato, S.; Hara, Y.; Shirai, T.; Noda, K.

2014-07-01

Multiple-energy synchrotron operation providing carbon-ion beams with various energies has been used for scanned particle therapy at NIRS. An energy range from 430 to 56 MeV/u and about 200 steps within this range are required to vary the Bragg peak position for effective treatment. The treatment also demands the slow extraction of beam with highly reliable properties, such as spill, position and size, for all energies. We propose an approach to generating multiple-energy operation meeting these requirements within a short time. In this approach, the device settings at most energy steps are determined without manual adjustments by using systematic parameter tuning depending on the beam energy. Experimental verification was carried out at the HIMAC synchrotron, and its results proved that this approach can greatly reduce the adjustment period.

Performance of the HIMAC beam control system using multiple-energy synchrotron operation

NASA Astrophysics Data System (ADS)

Mizushima, K.; Furukawa, T.; Iwata, Y.; Hara, Y.; Saotome, N.; Saraya, Y.; Tansho, R.; Sato, S.; Fujimoto, T.; Shirai, T.; Noda, K.

2017-09-01

Multiple-energy synchrotron operation was developed to realize fast 3D scanning irradiation for carbon-ion radiotherapy. This type of operation can output various carbon-ion beams with different energies in a single synchrotron cycle. The beam control system used in this kind of operation was developed to quickly provide the beam energy and intensity required from the irradiation control system. The performance of the system was verified by experimental tests. The system could output beams of 197 different energies in 63 s. The beam intensity could be controlled for all the output beams without large ripples or overshooting. The experimental test of irradiation for prostate cancer treatment was also successfully performed, and the test results proved that our system can greatly reduce the irradiation time.

Submillimeter (Lambda < 1 mm) Continuum Imaging at CSO: A Retrospective

NASA Technical Reports Server (NTRS)

Dowell, C. Darren

2009-01-01

This contribution is submitted on behalf of all students, postdocs, and staff inspired and supported by Tom Phillips to build an instrument and then wait for low precipitable water vapor. Over the 20 plus years of its existence, the Caltech Submillimeter Observatory (CSO) has seen a succession of ever more powerful detectors to measure continuum emission in the shortest submillimeter bands available from Mauna Kea. These instruments have been trained on the nearest solar systems, the most distant galaxies, and objects in between. I show several images collected over the 5 plus year history of the SHARC II camera and anecdotal comparison with past work.

Pebbles, Cobbles, and Sockets

NASA Technical Reports Server (NTRS)

1997-01-01

This Rover image of 'Shark' (upper left center), 'Half Dome' (upper right), and a small rock (right foreground) reveal textures and structures not visible in lander camera images. These rocks are interpreted as conglomerates because their surfaces have rounded protrusions up to several centimeters in size. It is suggested that the protrusions are pebbles and granules.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

Sojourner Rover View of Sockets and Pebbles

NASA Technical Reports Server (NTRS)

1997-01-01

Well-rounded objects, like the ones in this image, were not seen at the Viking sites. These are thought to be pebbles liberated from sedimentary rocks composed of cemented silts, sands and rounded fragments; such rocks are called conglomerates. The 'sockets' could be the former sites of such pebbles.

NOTE: original caption as published in Science Magazine

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

Construction of the GAMCIT gamma-ray burst detector (G-056)

NASA Technical Reports Server (NTRS)

Coward, Michael H.; Grunsfeld, John M.; Mccall, Benjamin J.; Ratner, Albert

1995-01-01

The GAMCIT (Gamma-ray Astrophysics Mission, California Institute of Technology) payload is a Get-Away-Special payload designed to search for high-energy gamma-ray bursts and any associated optical transients. This paper presents details on the development and construction of the GAMCIT payload. In addition, this paper will reflect upon the unique challenges involved in bringing the payload close to completion, as the project has been designed, constructed, and managed entirely by undergraduate members of the Caltech SEDS (Students for the Exploration and Development of Space). Our experience will definitely be valuable to other student groups interested in undertaking a challenge such as a Get-Away-Special payload.

Wind Tails Near Chimp

NASA Technical Reports Server (NTRS)

1997-01-01

This image of the rock 'Chimp' was taken by the Sojourner rover's right front camera on Sol 72 (September 15). Fine-scale texture on Chimp and other rocks is clearly visible. Wind tails, oriented from lower right to upper left, are seen next to small pebbles in the foreground. These were most likely produced by wind action.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

Stereo Images of Wind Tails Near Chimp

NASA Technical Reports Server (NTRS)

1997-01-01

This stereo image pair of the rock 'Chimp' was taken by the Sojourner rover's front cameras on Sol 72 (September 15). Fine-scale texture on Chimp and other rocks is clearly visible. Wind tails, oriented from lower right to upper left, are seen next to small pebbles in the foreground. These were most likely produced by wind action.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

Numerical time evolution of ETH spin chains by means of matrix product density operators

NASA Astrophysics Data System (ADS)

White, Christopher; Zaletel, Michael; Mong, Roger; Refael, Gil

We introduce a method for approximating density operators of 1D systems that, when combined with a standard framework for time evolution (TEBD), makes possible simulation of the dynamics of strongly thermalizing systems to arbitrary times. We demonstrate that the method works on both near-equilibrium initial states (Gibbs states with spatially varying temperatures) and far-from-equilibrium initial states, including quenches across phase transitions and pure states. This work was supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE \\x901144469 and by the Caltech IQIM, an NSF Physics Frontiers Center with support of the Gordon and Betty Moore.

The Visual Orbit of the 1.1 Day Spectroscopic Binary Sigma2 Coronae Borealis From Interferometry at the Chara Array

DTIC Science & Technology

2009-01-01

UBV bands from Grenier et al. (1985) and Perryman & ESA (1997), and JHKS bands from the Two Micron All Sky Survey9 ( 2MASS ) and transformed them to...calibrated 9 http://www.ipac.caltech.edu/ 2mass No. 1, 2009 σ 2 CrB VISUAL ORBIT 397 Table 2 Interferometric Visibilities for σ 2 CrB HJD Measured V σV...that a 10% change inΔK ′ for σ 2 CrB results in only 0.1% change in visibility. This, along with the poor-quality K magnitude listed in 2MASS (for σ 2

Detection of explosives, nerve agents, and illicit substances by zero-energy electron attachment

NASA Technical Reports Server (NTRS)

Chutjian, A.; Darrach, M. R.

2000-01-01

The Reversal Electron Attachment Detection (READ) method, developed at JPL/Caltech, has been used to detect a variety of substances which have electron-attachment resonances at low and intermediate electron energies. In the case of zero-energy resonances, the cross section (hence attachment probability and instrument sensitivity) is mediated by the so-called s-wave phenomenon, in which the cross sections vary as the inverse of the electron velocity. Hence this is, in the limit of zero electron energy or velocity, one of the rare cases in atomic and molecular physics where one carries out detection via infinite cross sections.

Dense modifiable interconnections utilizing photorefractive volume holograms

NASA Astrophysics Data System (ADS)

Psaltis, Demetri; Qiao, Yong

1990-11-01

This report describes an experimental two-layer optical neural network built at Caltech. The system uses photorefractive volume holograms to implement dense, modifiable synaptic interconnections and liquid crystal light valves (LCVS) to perform nonlinear thresholding operations. Kanerva's Sparse, Distributed Memory was implemented using this network and its ability to recognize handwritten character-alphabet (A-Z) has been demonstrated experimentally. According to Kanerva's model, the first layer has fixed, random weights of interconnections and the second layer is trained by sum-of-outer-products rule. After training, the recognition rates of the network on the training set (104 patterns) and test set (520 patterns) are 100 and 50 percent, respectively.

Disturbing Pop-Tart

NASA Technical Reports Server (NTRS)

1997-01-01

The Sojourner rover's front right camera imaged Pop-tart, a small rock or indurated soil material which was pushed out of the surrounding drift material by Sojourner's front left wheel during a soil mechanics experiment.

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

Minerva: A Dedicated Observatory for the Detection of Small Planets in the Solar Neighborhood

NASA Astrophysics Data System (ADS)

Hogstrom, Kristina; Johnson, J. A.; Wright, J.; McCrady, N.; Swift, J.; Muirhead, P.; Bottom, M.; Plavchan, P.; Zhao, M.; Riddle, R. L.

2013-01-01

Minerva is an array of 0.7m aperture robotic telescopes to be built atop Palomar Mountain outfitted for both photometry and high-resolution spectroscopy. It will be the first U.S. observatory dedicated to exoplanetary science capable of both precise radial velocimetry and transit studies. The multi-telescope concept will be implemented to either observe separate targets or a single target with a larger effective aperture. The flexibility of the observatory will maximize scientific potential and also provide ample opportunities for education and public outreach. The design and implementation of Minerva will be carried out by postdoctoral and student researchers at Caltech.

Extreme ultra-violet movie camera for imaging microsecond time scale magnetic reconnection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chai, Kil-Byoung; Bellan, Paul M.

2013-12-15

An ultra-fast extreme ultra-violet (EUV) movie camera has been developed for imaging magnetic reconnection in the Caltech spheromak/astrophysical jet experiment. The camera consists of a broadband Mo:Si multilayer mirror, a fast decaying YAG:Ce scintillator, a visible light block, and a high-speed visible light CCD camera. The camera can capture EUV images as fast as 3.3 × 10{sup 6} frames per second with 0.5 cm spatial resolution. The spectral range is from 20 eV to 60 eV. EUV images reveal strong, transient, highly localized bursts of EUV radiation when magnetic reconnection occurs.

Obituary: Jesse Greenstein, 1909-2002

NASA Astrophysics Data System (ADS)

Gunn, James Edward

2003-12-01

On the 21 October 2002, with the death of Jesse Greenstein, many of us in astronomy lost a beloved adopted father and astronomy lost one of its most influential leaders of the postwar era. Truly a giant is gone; it is easy to say that they don't make the likes of Greenstein, Spitzer, and Scharwarzschild any more, but it is unfortunately only the truth. The field has changed and grown enormously in the more than 50 years spanned by Jesse's career with no small part of this traceable directly to his efforts. His growth was shaped very much by world events. He enjoyed a quite comfortable childhood; he was born on 15 October 1909 to successful immigrant parents, Maurice and Leah, who indulged his early interests in astronomy, radio, and science in general; these interests were to remain with him the rest of his life. As a boy he thought physics dull and chemistry exciting, though later he was to be influential in the transformation of astronomy into astrophysics in this country. He was something of a prodigy, entering the Horace Mann School for boys (an excellent private high school) at age 11 and Harvard at age 16 (in 1926). He met and became close friends with Cecilia Payne, with whom he shared cultural and scientific passions. She was certainly the greatest female astronomer of the era but largely shunned and ignored by her colleagues. Thus began a curious ambivalence in his relationship with women in the field; in fact and in action he was highly supportive but much less so in word. He graduated with a BA in astronomy in October 1929, on the eve of the stock market crash. He stayed for one more year and obtained a Master's degree, prevented by ill health from a planned one-year visit to Oxford. His family had always assumed that he would forego his interest in research and take his place in the family's successful business and real estate endeavors and the seriousness of the market collapse impelled him, very much against his will, to do just that. He proved himself to be a capable manager, able to deal with difficult times and circumstances, and the family business prospered. However, his itch to be an astronomer did not falter, and in 1934, when he was convinced that the family business would survive without him, he returned to Harvard - over the objection of director Harlow Shapely who tried to persuade him that the field had advanced too far in his four-year absence for him ever to catch up! This same year he married his childhood sweetheart Naomi Kitay, whom he ever after affectionately called 'Kitty.' Naomi nourished the already-strong humanist streak in Jesse. Interested in, and passionate about, art and the theater, life in general, and whatever it was that absorbed her interest at the moment, she was a wonderful foil for Jesse's self-deprecatory and sometimes depressive moods. She died a few months before Jesse did; they had been married 66 years. At Harvard he pursued a very successful and prescient thesis on the scattering of light by interstellar grains, begun perhaps partly in an endeavor to alleviate his failure during a Master's research project to recognize the existence of dust absorption and reddening in the face of quite convincing data. His last days at Harvard were premonitory of things to come in his career. He and Fred Whipple wrote a paper attempting, quite unsuccessfully, to explain Karl Jansky's detection of strong radio emission from the center of the Galaxy as thermal emission; this was long before the existence of magnetic fields and relativistic electrons were even suspected. The problem was to wait 15 years for a solution. But Jansky's, and later Grote Reber's, observations resonated with Jesse's early interest in radio and presaged his later decisive support for radio astronomy in the U.S. In 1937 he was awarded a NRC fellowship, which he took to Yerkes Observatory. Attracted by the innovative and productive group assembled there by Otto Struve, he flourished. Still working on dust and the interstellar medium, he began a long and productive collaboration with theorist Louis Henyey. He also began his career in stellar spectroscopy at Struve's urging and did the first analysis of the peculiar hydrogen-poor object upsilon Sagittarii, thus beginning a love affair with peculiar stars and their compositions which was to last the rest of his career. During the war he and Henyey, as well as a number of other astronomers, managed to stay at Yerkes, largely putting aside astronomical research to work on the war effort. He and Henyey learned optics in the face of great difficulty (modern optical design techniques at the time being almost exclusively both proprietary and German) and produced many optical designs for the military, among which is the beautiful wide-angle, Henyey-Greenstein camera. After the war Jesse became very interested in, and supportive of, the vast changes to the field wrought by the technological developments during the war, including infrared detectors, photomultipliers, sensitive radio receivers, and rockets. Astronomy clearly stood on the threshold of a new and wonderful era, which he was determined to help usher in. The astronomical community had already recognized Jesse's genius and in 1948 he received an invitation he could not possibly refuse. He was invited to come to Caltech to build a department to do science with the soon to be completed 200-inch Hale telescope, by far the largest and most ambitious telescope project to that date. The family (there were now two sons, George and Peter) moved from the little town of Williams Bay, Wisconsin to the bustle of postwar Pasadena, California. One may well ask whether anyone, given an opportunity of this magnitude, could have failed to be great but the answer, I am certain, is that it would have been very easy indeed. It took all of Jesse's hard-won ability as a manager, his wonderful personal touch, his ease with moneyed supporters, and above all his unimpeachable scientific and personal integrity to build what is universally recognized as one of the finest departments in the world. The arcane political arrangements with the Carnegie Institution, which ran Mount Wilson and would later run both Mount Wilson and Palomar jointly with Caltech, were hammered out with Jesse's guidance before he had a chance to build the department. In the beginning the only two astronomers at Caltech were Jesse and Fritz Zwicky; Zwicky was a genius but personally incredibly difficult and Jesse was very much alone in navigating the difficult political waters. His view of the way to build the department, which time has certainly vindicated, was to hire the best international theorists he could find. He was convinced they were the smartest people being trained at that time and convinced as well that the lure of the great telescope would transform them into capable observers who would soon understand their data from an astrophysical perspective. This was wildly successful. He built a postdoctoral program around stellar abundance determinations, funded by the Air Force and aided by the many military contacts he had made during and after the war. He managed, in his tiny department, to lure the most able students in the field. The list of names among the early students and the ``graduates" of the abundance project is a who's who of astronomy: Allan Sandage, Helmut Abt, George Wallerstein, Halton Arp, Wallace Sargent, Leonard Searle, to name only a representative few. His own research continued unabated; he returned to the subject of dust with Leverett Davis and, in 1951, they proposed the magnetic alignment mechanism to explain interstellar polarization that survives essentially unchanged to the present - certainly one of the longest-lived theoretical results in the field. At Caltech's Kellogg Radiation Laboratory, there was much interest in the nuclear reactions that provide stars their energy and potentially result in observable abundance changes. This work fit hand-in-glove with Jesse's interest in stars of peculiar abundance and he forged close scientific ties with the Kellogg team, particularly Willy Fowler. Jesse arranged a controversial visit to Caltech by Fred Hoyle (Hoyle's steady state cosmology was not popular among Caltech physicists) and Hoyle's protégés Geoff and Margaret Burbidge. Their classic work with Fowler on nucleosynthesis arose from this visit. Later his research turned increasingly toward understanding the denizens of the lower left of the Hertzsprung-Russell diagram - white dwarfs, blue subdwarfs, and nuclei of planetary nebulae. He became the observational authority on such stars, and much of our current understanding of these objects is a direct outgrowth of his work. In the course of this work he obtained several spectra of faint blue objects with weak, broad emission lines that were not readily identifiable. The realization that compact stars could have very strong magnetic fields was then current, and he felt that most of these objects could be explained by peculiar Zeeman and pressure effects on the spectra of intrinsically faint degenerate objects. The quasar story has been told many times, but the realization by Maarten Schmidt in 1963 that the spectrum of 3C273 was consistent with a redshift of 16 percent led them to reassess Jesse's work on 3C48, a quasi-stellar radio source with a spectrum similar to some of the peculiar blue "stars" in his library of spectra: this turned out to be the second QSO redshift recognized, with a value of 0.37. In 1960, Jesse had obtained a spectrum of Ton 202, which he had confidently identified as a peculiar DC white dwarf 40 pc distant. When he went through his library of spectra with an eye toward new possibilities, it turned out to be a QSO with a redshift of 0.37, continuing his penchant for being right almost all the time, but with the occasional really spectacular mistake. He characterized his research and the rather frequent and profound changes of direction in a very characteristic way - he very actively wanted to skim the cream off new subjects and establish correct directions for research, but he did not care for pedantic detail. It is clear from his record that this did not mean that he was ill equipped to dig deeply; his work on dust in particular was very difficult stuff. He simply felt that he had the tools at his disposal to help at the very frontiers of astronomical research and preferred to leave the details to others. Even before he came to Caltech in 1948, Jesse was convinced by the work of Jansky and Reber, and later the British and Australians, that radio astronomy was of vast importance to the field, and he was determined that Caltech should be a center. He fought for the founding of a radio astronomy group by first gaining institutional acceptance - which was not easy - and then obtaining federal funding for the Owens Valley Radio Observatory (OVRO) in 1954 from the Office of Naval Research. In this context, it is important to note that astronomy in the U.S. had been, for a very long time, almost exclusively privately funded and the Caltech abundance project and the radio astronomy observatory were among the first large departures from this norm. Jesse's task was made even more difficult by the connection with the Carnegie Institution, which at the time had specific rules against seeking federal funds. He gradually built Caltech astronomy into the powerhouse it has been for many years. Along the way he fostered and welcomed promising new technology, beginning with photomultipliers, through radio astronomy techniques, vidicons, CCDs, and computers. His views on computers as tools for doing theory, namely that they basically trivialize theoretical research (he would not have said it ``exactly" that way) would certainly be very unpopular today. Jesse's role on the national scene was profound and controversial. He was instrumental in persuading the Navy and Air Force to fund astronomical research and he was active in the founding of the National Science Foundation; he chaired the first NSF advisory committee in astronomy. He served on countless government advisory committees and worked with other Caltech physicists in highly classified research until well after such work became highly unpopular on campuses. He pushed very hard for the founding of the national observatories, particularly NRAO. He was one of the organizers of the conference in 1954, which was explicitly aimed at convincing the government to establish NRAO - the same year he obtained funds from the Navy to build Caltech's private OVRO, which was for a long time in direct competition with the national observatory. He was also influential in the founding of the national optical observatory at Kitt Peak, though this was to be a very contentious issue later. He was chosen in 1970 to lead the second National Academy decade review of astronomy, after the ground breaking Whitford report a decade earlier. It is generally conceded that the Greenstein report was the most successful of these efforts to date in the face of a rather austere funding climate; this effort was aided by the cohesive spirit of the community, but also because of the wisdom that he brought to the enterprise. His view on the best way to conduct science was explicitly and very frankly intellectually elitist. The very best people at the very best institutions, he thought, should be supported to the fullest extent possible with money and technological support wherever it could be found. He had built the Caltech department from a gleam in George Ellery Hale's eye to one of the preeminent astronomical research institution in the world, and was proud of it. He felt that the nation owed it to science for its own sake and as a nation to support science fully. He wrote in his memoir, ``An Astronomical Life," in the "Annual Reviews of Astronomy and Astrophysics": ``Human illness and poverty cannot be cured merely by spending money, but the human condition can be ennobled by spending money wisely." He did not think that spending vast amounts of money at Kitt Peak to build giant telescopes for the whole community was the best way to spend said vast amounts of money. He felt that the elite universities had demonstrated the ability both to build big instruments (the 200-inch, the 120-inch) and to attract the astronomical staff to operate them and to do superb science with them. If the federal government were to spend the money, it should clearly go to those universities. In any event, these universities should not be allowed to wither as the national observatories grew. Curiously, his view of NRAO was very different and he personally was enthusiastic about the construction of the VLA; indeed, it was the highest-priority project of the Greenstein report. In any document such as this, one must mention offices and awards. Jesse was awarded and held most of them: the Gold Medal of the RAS, the Russell Lectureship, the Bruce Medal, the Vice Presidency of the AAS, a (controversial) chairmanship of AURA, membership in the National Academy, chairmanship of many of its, and other government, advisory committees as well as chairmanship of the decadal review. He held the first Lee DuBridge chair at Caltech. While he was appreciative of these awards, he felt that awards and honors usually came too late in a scientist's career to be useful. He was a superb scientist and skillful manager and administrator, but no description of Jesse, especially this memorial one, can possibly be complete without some attempt to describe him as a human being. It was shortly before the QSO era, in 1961, that I, as a green graduate student, first met Jesse. I was in awe, of course, but it soon became clear that there was not even a stern exterior to this remarkable man who had built the Caltech department, and who was very much a personification of American astronomy. He cared deeply about everyone in his department and clearly prided himself as an amateur psychologist. He was always available, charming, warm, and open, and eager to discuss and help with personal problems as well as scientific ones with seemingly equal willingness and enthusiasm. Naomi was called in for help with stubborn personal problems and their house on San Pasqual street was a warm, inviting place and the location of countless formal and raucous informal parties and gatherings. I never worked with him directly as a student, but felt that I knew him better than any of the faculty with whom I did work. All of the words I have read in tribute to Jesse mention him as a father; he was certainly mine, and I (and all of his many children) will miss him terribly.

Multifunctional synchrotron spectrometer of the National Research Center "Kurchatov Institute": I. EXAFS in dispersive mode

NASA Astrophysics Data System (ADS)

Aksenov, V. L.; Tyutyunnikov, S. I.; Shalyapin, V. N.; Belyaev, A. D.; Artemiev, A. N.; Artemiev, N. A.; Kirillov, B. F.; Kovalchiuk, M. V.; Demkiv, A. A.; Knyazev, G. A.

2017-01-01

The improved X-ray optical scheme, the system of registration, and the measurement procedure of the multifunctional synchrotron radiation spectrometer in the dispersive EXAFS mode are described. The results of the spectrometer energy resolution measurements are given. The advantages and disadvantages of traditional and dispersive EXAFS spectrometers are analyzed. Examples of EXAFS spectra measured in the dispersive mode are given.

Coherent synchrotron radiation for laminar flows

NASA Astrophysics Data System (ADS)

Schmekel, Bjoern S.; Lovelace, Richard V. E.

2006-11-01

We investigate the effect of shear in the flow of charged particle equilibria that are unstable to the coherent synchrotron radiation (CSR) instability. Shear may act to quench this instability because it acts to limit the size of the region with a fixed phase relation between emitters. The results are important for the understanding of astrophysical sources of coherent radiation where shear in the flow is likely.

Low-pressure Structural Modification of Aluminum Hydride

DTIC Science & Technology

2011-02-01

Acknowledgments Use of the National Synchrotron Light Source (NSLS), Brookhaven National Laboratory ( BNL ) was supported by the U.S. Department of Energy...National Synchrotron Light Source (NSLS) of Brookhaven National Laboratory ( BNL ). The spectral resolution of ±4 cm–1 was used for all IR measurements...12 List of Symbols, Abbreviations, and Acronyms Al aluminum AlH3 aluminum hydride BNL Brookhaven National Laboratory EOS equation of

1994 Activity Report, National Synchrotron Light Source. Annual report, October 1, 1993-September 30, 1994

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rothman, E.Z.

1995-05-01

This report is a summary of activities carried out at the National Synchrotron Light Source during 1994. It consists of sections which summarize the work carried out in differing scientific disciplines, meetings and workshops, operations experience of the facility, projects undertaken for upgrades, administrative reports, and collections of abstracts and publications generated from work done at the facility.

Improvement of the efficient referencing and sample positioning system for micro focused synchrotron X-ray techniques

NASA Astrophysics Data System (ADS)

Spangenberg, T.; Göttlicher, J.; Steininger, R.

2016-05-01

An efficient referencing and sample positioning system is a basic tool for a micro focus beamline at a synchrotron. The seven years ago introduced command line based system was upgraded at SUL-X beamline at ANKA [1]. A new combination of current server client techniques offers direct control and facilitates unexperienced users the handling of this frequently used tool.

An Efficient Referencing And Sample Positioning System To Investigate Heterogeneous Substances With Combined Microfocused Synchrotron X-ray Techniques

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spangenberg, Thomas; Goettlicher, Joerg; Steininger, Ralph

2009-01-29

A referencing and sample positioning system has been developed to transfer object positions measured with an offline microscope to a synchrotron experimental station. The accuracy should be sufficient to deal with heterogeneous samples on micrometer scale. Together with an online fluorescence mapping visualisation the optical alignment helps to optimize measuring procedures for combined microfocused X-ray techniques.

Shining a light on Jarosite: formation, alteration and stability studies using in situ experimental synchrotron and neutron techniques.

NASA Astrophysics Data System (ADS)

Brand, H. E. A.; Scarlett, N. V. Y.; Wilson, S. A.; Frierdich, A. J.; Grey, I. E.

2016-12-01

Jarosites and related minerals are critical to a range of mineral processing and research applications. They are used in the removal of iron species from smelting processes; they occur in metal bioleaching systems, and they are present in acid mine drainage environments. There has been a recent resurgence in interest in jarosites since their detection on Mars. In this context, the presence of jarosite has been recognised as a likely indicator of liquid water at the surface of Mars in the past & it is thought that their study will provide insight into the environmental history of Mars. Acid sulfate soils cover large areas of the Australian coastline and are likely to be a major constituent of the Martian environment. The oxidation of acid sulfate soils, coupled with potential release of heavy metals and acidic groundwaters, can have serious consequences for fragile ecosystems. Understanding these sediments will provide insight into the biogeochemical processes that affect the lifetimes of transient mineral species on Earth, and may be used to better understand soil acidification, contaminant mobility at sites affected by acid and metalliferous drainage, and even constrain past weathering and putative biosignatures on Mars. Knowledge of the behaviour of jarosite minerals under the actual conditions that they are found in is crucial to understanding their potential environmental impacts on both Earth and Mars. To this end, we are engaged in a program to study the formation, stability and alteration of natural and synthetic jarosite minerals using a complementary suite of in situ synchrotron and neutron techniques. There are 3 sections to this work that will introduce the experimental techniques and sample environments that make these measurements possible: Studying the nucleation and growth of jarosites under laboratory conditions. The experimentation consisted of time-resolved synchrotron small angle X-ray scattering and X-ray diffraction. Studying the stability of natural & synthetic jarosites with temperature and pressure using synchrotron and neutron diffraction. Parallel neutron and X-ray imaging at OPAL and the Australian Synchrotron, combined with synchrotron pseudo-microdiffraction to map the mineralogy and structural relationships within naturally occurring jarosite nodules.

Contrast agent choice for intravenous coronary angiography

NASA Astrophysics Data System (ADS)

Zeman, H. D.; Siddons, D. P.

1990-05-01

The screening of the general population for coronary artery disease would be practical if a method existed for visualizing the extent of occlusion after an intravenous injection of contrast agent. Measurements performed with monochromatic synchrotron radiation X-rays and an iodine-containing contrast agent at the Stanford Synchrotron Radiation Laboratory have shown that such an intravenous angiography procedure would be possible with an adequately intense monochromatic X-ray source. Because of the size and cost of synchrotron radiation facilities it would be desirable to make the most efficient use of the intensity available, while reducing as much as possible the radiation dose experienced by the patient. By choosing contrast agents containing elements with a higher atomic number than iodine, it is possible to both improve the image quality and reduce the patient radiation dose, while using the same synchrotron radiation source. By using Si monochromator crystals with a small mosaic spread, it is possible to increase the X-ray flux available for imaging by over an order of magnitude, without any changes in the storage ring or wiggler magnet. The most critical imaging task for intravenous coronary angiography utilizing synchrotron radiation X-rays is visualizing a coronary artery through the left ventricle or aorta which also contain contrast agent. Calculations have been made of the signal to noise ratio expected for this imaging task for various contrast agents with atomic numbers between that of iodine and bismuth. The X-ray energy spectrum of the X-17 superconduction wiggler beam line at the National Synchrotron Light Source at Brookhaven National Laboratory has been used for these calculations. Both perfect Si crystals and Si crystals with a small mosaic spread are considered as monochromators. Contrast agents containing Gd or Yb seem to have about the optimal calculated signal to noise ratio. Gd-DTPA is already approved for use as a contrast agent for magnetic resonance imaging. Experiments have already been performed with Yb-DTPA in animals, and it appears to have a lower toxicity than that of Gd-DTPA. Reported animal experiments with Gd-DOTA contrast agent show no toxicity at all.

Understanding space charge and controlling beam loss in high intensity synchrotrons

NASA Astrophysics Data System (ADS)

Cousineau, Sarah M.

Future high intensity synchrotrons will require unprecedented control of beam loss in order to comply with radiation safety regulations and to allow for safe, hands-on maintenance of machine hardware. A major cause of beam loss in high intensity synchrotrons is the space charge force of the beam, which can lead to beam halo and emittance dilution. This dissertation presents a comprehensive study of space charge effects in high intensity synchrotron beams. Experimental measurements taken at the Proton Storage Ring (PSR) in Los Alamos National Laboratory and detailed simulations of the experiments are used to identify and characterize resonances that affect these beams. The collective motion of the beam is extensively studied and is shown to be more relevant than the single particle dynamics in describing the resonance response. The emittance evolution of the PSR beam and methods for reducing the space-charge-induced emittance growth are addressed. In a separate study, the emittance evolution of an intense space charge beam is experimentally measured at the Cooler Injector Synchrotron (CIS) at Indiana University. This dissertation also investigates the sophisticated two-stage collimation system of the future Spallation Neutron Source (SNS) high intensity accumulator ring. A realistic Monte-Carlo collimation simulation is developed and used to optimize the SNS ring collimation system parameters. The finalized parameters and predicted beam loss distribution around the ring are presented. The collimators will additionally be used in conjunction with a set of fast kickers to remove the beam from the gap region before the rise of the extraction magnets. The gap cleaning process is optimized and the cleaning efficiency versus momentum spread of the beam is examined.

A Study of Short-Term Variations in Jupiter's Synchrotron Emission

NASA Technical Reports Server (NTRS)

Klein, M.J.; Gulkis, S.; Bolton, S. J.; Levin, S. M.

1999-01-01

Earth-based observations of the flux density and polarization of Jupiter's microwave emission provide useful data to test and constrain computational models of synchrotron radio emission from the inner regions of the Jovian magnetosphere. Stimulated by the sudden brightening of the synchrotron emission caused by the impacts of comet Shoemaker-Levy 9 in 1994, the observational techniques of the NASA-JPL Jupiter Patrol were modified to search for other short-term variations unrelated to the SL-9 event. The characteristics of the improved data base are described and the results of the search for variability on timescales of 5 to 100 days are reported. The first results of Jupiter observations from the Goldstone-Apple Valley Radio Telescope (GAVRT) project are reported and included in the data base. GAVRT is a new project in science education that engages middle- and high school students in science research. The paper also includes new observations of Jupiter's rotational beamed emission, commonly known as the "beaming curve", that describes the observed flux density as a function of System III longitude. The shape of the "beaming curve" is known to change with the parameter D(sub E), the declination of the earth relative to Jupiter's rotational equator. While the history of Jupiter's beaming curve exhibits remarkable stability and repeatability as a function of D(sub E), there may be evidence for short term departures from the nominal curves. Data supporting this tentative conclusion are presented. Preliminary results of a study comparing the observations and computer simulations of the synchrotron beaming curve will also be presented and discussed (see companion paper, "Modeling Jupiter's Synchrotron Emission", by Bolton et. al.). The research reported in this paper was performed by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.

High-spatial-resolution mapping of superhydrophobic cicada wing surface chemistry using infrared microspectroscopy and infrared imaging at two synchrotron beamlines.

PubMed

Tobin, Mark J; Puskar, Ljiljana; Hasan, Jafar; Webb, Hayden K; Hirschmugl, Carol J; Nasse, Michael J; Gervinskas, Gediminas; Juodkazis, Saulius; Watson, Gregory S; Watson, Jolanta A; Crawford, Russell J; Ivanova, Elena P

2013-05-01

The wings of some insects, such as cicadae, have been reported to possess a number of interesting and unusual qualities such as superhydrophobicity, anisotropic wetting and antibacterial properties. Here, the chemical composition of the wings of the Clanger cicada (Psaltoda claripennis) were characterized using infrared (IR) microspectroscopy. In addition, the data generated from two separate synchrotron IR facilities, the Australian Synchrotron Infrared Microspectroscopy beamline (AS-IRM) and the Synchrotron Radiation Center (SRC), University of Wisconsin-Madison, IRENI beamline, were analysed and compared. Characteristic peaks in the IR spectra of the wings were assigned primarily to aliphatic hydrocarbon and amide functionalities, which were considered to be an indication of the presence of waxy and proteinaceous components, respectively, in good agreement with the literature. Chemical distribution maps showed that, while the protein component was homogeneously distributed, a significant degree of heterogeneity was observed in the distribution of the waxy component, which may contribute to the self-cleaning and aerodynamic properties of the cicada wing. When comparing the data generated from the two beamlines, it was determined that the SRC IRENI beamline was capable of producing higher-spatial-resolution distribution images in a shorter time than was achievable at the AS-IRM beamline, but that spectral noise levels per pixel were considerably lower on the AS-IRM beamline, resulting in more favourable data where the detection of weak absorbances is required. The data generated by the two complementary synchrotron IR methods on the chemical composition of cicada wings will be immensely useful in understanding their unusual properties with a view to reproducing their characteristics in, for example, industry applications.

ELECTRON ACCELERATION IN PULSAR-WIND TERMINATION SHOCKS: AN APPLICATION TO THE CRAB NEBULA GAMMA-RAY FLARES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kroon, John J.; Becker, Peter A.; Dermer, Charles D.

The γ -ray flares from the Crab Nebula observed by AGILE and Fermi -LAT reaching GeV energies and lasting several days challenge the standard models for particle acceleration in pulsar-wind nebulae because the radiating electrons have energies exceeding the classical radiation-reaction limit for synchrotron. Previous modeling has suggested that the synchrotron limit can be exceeded if the electrons experience electrostatic acceleration, but the resulting spectra do not agree very well with the data. As a result, there are still some important unanswered questions about the detailed particle acceleration and emission processes occurring during the flares. We revisit the problem usingmore » a new analytical approach based on an electron transport equation that includes terms describing electrostatic acceleration, stochastic wave-particle acceleration, shock acceleration, synchrotron losses, and particle escape. An exact solution is obtained for the electron distribution, which is used to compute the associated γ -ray synchrotron spectrum. We find that in our model the γ -ray flares are mainly powered by electrostatic acceleration, but the contributions from stochastic and shock acceleration play an important role in producing the observed spectral shapes. Our model can reproduce the spectra of all the Fermi -LAT and AGILE flares from the Crab Nebula, using magnetic field strengths in agreement with the multi-wavelength observational constraints. We also compute the spectrum and duration of the synchrotron afterglow created by the accelerated electrons, after they escape into the region on the downstream side of the pulsar-wind termination shock. The afterglow is expected to fade over a maximum period of about three weeks after the γ -ray flare.« less

CCD sensors in synchrotron X-ray detectors

NASA Astrophysics Data System (ADS)

Strauss, M. G.; Naday, I.; Sherman, I. S.; Kraimer, M. R.; Westbrook, E. M.; Zaluzec, N. J.

1988-04-01

The intense photon flux from advanced synchrotron light sources, such as the 7-GeV synchrotron being designed at Argonne, require integrating-type detectors. Charge-coupled devices (CCDs) are well suited as synchrotron X-ray detectors. When irradiated indirectly via a phosphor followed by reducing optics, diffraction patterns of 100 cm 2 can be imaged on a 2 cm 2 CCD. With a conversion efficiency of ˜ 1 CCD electron/X-ray photon, a peak saturation capacity of > 10 6 X-rays can be obtained. A programmable CCD controller operating at a clock frequency of 20 MHz has been developed. The readout rate is 5 × 10 6 pixels/s and the shift rate in the parallel registers is 10 6 lines/s. The test detector was evaluated in two experiments. In protein crystallography diffraction patterns have been obtained from a lysozyme crystal using a conventional rotating anode X-ray generator. Based on these results we expect to obtain at a synchrotron diffraction images at a rate of ˜ 1 frame/s or a complete 3-dimensional data set from a single crystal in ˜ 2 min. In electron energy-loss spectroscopy (EELS), the CCD was used in a parallel detection mode which is similar to the mode array detectors are used in dispersive EXAFS. With a beam current corresponding to 3 × 10 9 electron/s on the detector, a series of 64 spectra were recorded on the CCD in a continuous sequence without interruption due to readout. The frame-to-frame pixel signal fluctuations had σ = 0.4% from which DQE = 0.4 was obtained, where the detector conversion efficiency was 2.6 CCD electrons/X-ray photon. These multiple frame series also showed the time-resolved modulation of the electron microscope optics by stray magnetic fields.

γ-Ray and Parsec-scale Jet Properties of a Complete Sample of Blazars From the MOJAVE Program

NASA Astrophysics Data System (ADS)

Lister, M. L.; Aller, M.; Aller, H.; Hovatta, T.; Kellermann, K. I.; Kovalev, Y. Y.; Meyer, E. T.; Pushkarev, A. B.; Ros, E.; MOJAVE Collaboration; Ackermann, M.; Antolini, E.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Boeck, M.; Bonamente, E.; Borgland, A. W.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caraveo, P. A.; Casandjian, J. M.; Cavazzuti, E.; Cecchi, C.; Chang, C. S.; Charles, E.; Chekhtman, A.; Cheung, C. C.; Chiang, J.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Conrad, J.; Cutini, S.; de Palma, F.; Dermer, C. D.; Silva, E. do Couto e.; Drell, P. S.; Drlica-Wagner, A.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Finke, J.; Focke, W. B.; Fortin, P.; Fukazawa, Y.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Germani, S.; Giglietto, N.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Guiriec, S.; Hadasch, D.; Hayashida, M.; Hays, E.; Horan, D.; Hughes, R. E.; Jóhannesson, G.; Johnson, A. S.; Kadler, M.; Katagiri, H.; Kataoka, J.; Knödlseder, J.; Kuss, M.; Lande, J.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Mazziotta, M. N.; McConville, W.; McEnery, J. E.; Mehault, J.; Michelson, P. F.; Mizuno, T.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Naumann-Godo, M.; Nishino, S.; Nolan, P. L.; Norris, J. P.; Nuss, E.; Ohno, M.; Ohsugi, T.; Okumura, A.; Omodei, N.; Orlando, E.; Ozaki, M.; Paneque, D.; Parent, D.; Pesce-Rollins, M.; Pierbattista, M.; Piron, F.; Pivato, G.; Rainò, S.; Readhead, A.; Reimer, A.; Reimer, O.; Richards, J. L.; Ritz, S.; Sadrozinski, H. F.-W.; Sgrò, C.; Shaw, M. S.; Siskind, E. J.; Spandre, G.; Spinelli, P.; Takahashi, H.; Tanaka, T.; Thayer, J. G.; Thayer, J. B.; Thompson, D. J.; Tosti, G.; Tramacere, A.; Troja, E.; Usher, T. L.; Vandenbroucke, J.; Vasileiou, V.; Vianello, G.; Vitale, V.; Waite, A. P.; Wang, P.; Winer, B. L.; Wood, K. S.; Zimmer, S.; Fermi LAT Collaboration

2011-11-01

We investigate the Fermi Large Area Telescope γ-ray and 15 GHz Very Long Baseline Array radio properties of a joint γ-ray and radio-selected sample of active galactic nuclei (AGNs) obtained during the first 11 months of the Fermi mission (2008 August 4-2009 July 5). Our sample contains the brightest 173 AGNs in these bands above declination -30° during this period, and thus probes the full range of γ-ray loudness (γ-ray to radio band luminosity ratio) in the bright blazar population. The latter quantity spans at least 4 orders of magnitude, reflecting a wide range of spectral energy distribution (SED) parameters in the bright blazar population. The BL Lac objects, however, display a linear correlation of increasing γ-ray loudness with synchrotron SED peak frequency, suggesting a universal SED shape for objects of this class. The synchrotron self-Compton model is favored for the γ-ray emission in these BL Lac objects over external seed photon models, since the latter predict a dependence of Compton dominance on Doppler factor that would destroy any observed synchrotron SED-peak-γ-ray-loudness correlation. The high-synchrotron peaked (HSP) BL Lac objects are distinguished by lower than average radio core brightness temperatures, and none display large radio modulation indices or high linear core polarization levels. No equivalent trends are seen for the flat-spectrum radio quasars (FSRQs) in our sample. Given the association of such properties with relativistic beaming, we suggest that the HSP BL Lac objects have generally lower Doppler factors than the lower-synchrotron peaked BL Lac objects or FSRQs in our sample.

Time resolved analysis of Fermi gamma-ray bursts with fast-and slow-cooled synchrotron photon models

DOE PAGES

Burgess, J. M.; Preece, R. D.; Connaughton, V.; ...

2014-02-27

Time-resolved spectroscopy is performed on eight bright, long gamma-ray bursts (GRBs) dominated by single emission pulses that were observed with the Fermi Gamma-Ray Space Telescope. Fitting the prompt radiation of GRBs by empirical spectral forms such as the Band function leads to ambiguous conclusions about the physical model for the prompt radiation. Moreover, the Band function is often inadequate to fit the data. Therefore, the GRB spectrum is modeled with two emission components consisting of optically thin non-thermal synchrotron radiation from relativistic electrons and, when significant, thermal emission from a jet photosphere, which is represented by a blackbody spectrum. Inmore » order to produce an acceptable fit, the addition of a blackbody component is required in five out of the eight cases. We also find that the low-energy spectral index α is consistent with a synchrotron component with α = –0.81 ± 0.1. This value lies between the limiting values of α = –2/3 and α = –3/2 for electrons in the slow- and fast-cooling regimes, respectively, suggesting ongoing acceleration at the emission site. The blackbody component can be more significant when using a physical synchrotron model instead of the Band function, illustrating that the Band function does not serve as a good proxy for a non-thermal synchrotron emission component. The temperature and characteristic emission-region size of the blackbody component are found to, respectively, decrease and increase as power laws with time during the prompt phase. Additionally, we find that the blackbody and non-thermal components have separate temporal behaviors as far as their respective flux and spectral evolutions.« less

Synchrotron IR microspectroscopy for protein structure analysis: Potential and questions

DOE PAGES

Yu, Peiqiang

2006-01-01

Synchrotron radiation-based Fourier transform infrared microspectroscopy (S-FTIR) has been developed as a rapid, direct, non-destructive, bioanalytical technique. This technique takes advantage of synchrotron light brightness and small effective source size and is capable of exploring the molecular chemical make-up within microstructures of a biological tissue without destruction of inherent structures at ultra-spatial resolutions within cellular dimension. To date there has been very little application of this advanced technique to the study of pure protein inherent structure at a cellular level in biological tissues. In this review, a novel approach was introduced to show the potential of the newly developed, advancedmore » synchrotron-based analytical technology, which can be used to localize relatively “pure“ protein in the plant tissues and relatively reveal protein inherent structure and protein molecular chemical make-up within intact tissue at cellular and subcellular levels. Several complex protein IR spectra data analytical techniques (Gaussian and Lorentzian multi-component peak modeling, univariate and multivariate analysis, principal component analysis (PCA), and hierarchical cluster analysis (CLA) are employed to relatively reveal features of protein inherent structure and distinguish protein inherent structure differences between varieties/species and treatments in plant tissues. By using a multi-peak modeling procedure, RELATIVE estimates (but not EXACT determinations) for protein secondary structure analysis can be made for comparison purpose. The issues of pro- and anti-multi-peaking modeling/fitting procedure for relative estimation of protein structure were discussed. By using the PCA and CLA analyses, the plant molecular structure can be qualitatively separate one group from another, statistically, even though the spectral assignments are not known. The synchrotron-based technology provides a new approach for protein structure research in biological tissues at ultraspatial resolutions.« less

Fevers and Chills: Separating thermal and synchrotron components in SNR spectra

NASA Astrophysics Data System (ADS)

Fedor, Emily Elizabeth; Martina-Hood, Hyourin; Stage, Michael D.

2018-06-01

Spatially-resolved spectroscopy is an extremely powerful tool in X-ray analysis of extended sources, but can be computationally difficult if a source exhibits complex morphology. For example, high-resolution Chandra data of bright Galactic supernova remnants (Cas A, Tycho, etc.) allow extractions of high-quality spectra from tens to hundreds of thousands of regions, providing a rich laboratory for localizing emission from processes such as thermal line emission, bremsstrahlung, and synchrotron. This soft-band analysis informs our understanding of the typically nonthermal hard X-ray emission observed with other lower-resolution instruments. The analysis is complicated by both projection effects and the presence of multiple emission mechanisms in some regions. In particular, identifying regions with significant nonthermal emission is critical to understanding acceleration processes in remnants. Fitting tens of thousands of regions with complex, multi-component models can be time-consuming and involve so many free parameters that little constraint can be placed on the values. Previous work by Stage & Allen ('06, '07, '11) on Cas A used a technique to identify regions dominated by the highest-cutoff synchrotron emission by fitting with a simple thermal emission model and identifying regions with anomalously high apparent temperatures (caused by presence of the high-energy tail of the synchrotron emission component). Here, we present a similar technique. We verify the previous approach and, more importantly, expand it to include a method to identify regions containing strong lower-cutoff synchrotron radiation. Such regions might be associated with the reverse-shock of a supernova. Identification of a nonthermal electron population in the interior of an SNR would have significant implications for the energy balance and emission mechanisms producing the high-energy (> 10 keV) spectrum.

Additional Spitzer IRS Spectroscopy of Three Intermediate Polars: The Detection of a Mid-infrared Synchrotron Flare from V1223 Sagittarii

NASA Astrophysics Data System (ADS)

Harrison, Thomas E.; Bornak, Jillian; Rupen, Michael P.; Howell, Steve B.

2010-02-01

We present new Spitzer Infrared Spectrograph (IRS) observations of three intermediate polars: V1223 Sgr, EX Hya, and V603 Aql. We detected a strong, fading flare event from V1223 Sgr. During this event, the flux declined by a factor of 13 in 30 minutes. Given the similarity in the slope of its mid-infrared spectrum during this event to that of AE Aqr, we suggest that this event was caused by transient synchrotron emission. Thus, V1223 Sgr becomes the third cataclysmic variable known to be a synchrotron source. We were unable to confirm the mid-infrared excess noted by Harrison et al. (Paper I) for EX Hya, suggesting that this object is either not a synchrotron source, or is slightly variable. Due to a very high background, V603 Aql was not detected in the long-wavelength regions accessible to the IRS. Given the recent detection of SS Cygni at radio wavelengths during outburst, we extract archival Spitzer IRS spectra for this source obtained during two successive maxima. These spectra do not show a strong excess, but without simultaneous data at shorter wavelengths, it is not possible to determine whether there is any contribution to the mid-infrared fluxes from a synchrotron jet. Includes observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência e Tecnologia (Brazil), and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina).

{gamma}-RAY AND PARSEC-SCALE JET PROPERTIES OF A COMPLETE SAMPLE OF BLAZARS FROM THE MOJAVE PROGRAM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lister, M. L.; Hovatta, T.; Aller, M.

We investigate the Fermi Large Area Telescope {gamma}-ray and 15 GHz Very Long Baseline Array radio properties of a joint {gamma}-ray and radio-selected sample of active galactic nuclei (AGNs) obtained during the first 11 months of the Fermi mission (2008 August 4-2009 July 5). Our sample contains the brightest 173 AGNs in these bands above declination -30 Degree-Sign during this period, and thus probes the full range of {gamma}-ray loudness ({gamma}-ray to radio band luminosity ratio) in the bright blazar population. The latter quantity spans at least 4 orders of magnitude, reflecting a wide range of spectral energy distribution (SED)more » parameters in the bright blazar population. The BL Lac objects, however, display a linear correlation of increasing {gamma}-ray loudness with synchrotron SED peak frequency, suggesting a universal SED shape for objects of this class. The synchrotron self-Compton model is favored for the {gamma}-ray emission in these BL Lac objects over external seed photon models, since the latter predict a dependence of Compton dominance on Doppler factor that would destroy any observed synchrotron SED-peak-{gamma}-ray-loudness correlation. The high-synchrotron peaked (HSP) BL Lac objects are distinguished by lower than average radio core brightness temperatures, and none display large radio modulation indices or high linear core polarization levels. No equivalent trends are seen for the flat-spectrum radio quasars (FSRQs) in our sample. Given the association of such properties with relativistic beaming, we suggest that the HSP BL Lac objects have generally lower Doppler factors than the lower-synchrotron peaked BL Lac objects or FSRQs in our sample.« less

Enhanced relativistic harmonics by electron nanobunching

NASA Astrophysics Data System (ADS)

an der Brügge, D.; Pukhov, A.

2010-03-01

It is shown that when a few-cycle, relativistically intense, p-polarized laser pulse is obliquely incident on overdense plasma, the surface electrons may form ultrathin, highly compressed layers with a width of a few nanometers. These electron "nanobunches" emit synchrotron radiation coherently. We calculate the one-dimensional synchrotron spectrum analytically and obtain a slowly decaying power law with an exponent of 4/3 or 6/5. This is much flatter than the 8/3 power of the Baeva-Gordienko-Pukhov spectrum, produced by a relativistically oscillating bulk skin layer. The synchrotron spectrum cutoff frequency is defined either by the electron relativistic γ-factor or by the thickness of the emitting layer. In the numerically demonstrated, locally optimal case, the radiation is emitted in the form of a single attosecond pulse, which contains almost the entire energy of the full optical cycle.

MICROSCANNING XRF, XANES, AND XRD STUDIES OF THEDECORATED SURFACE OF ROMAN TERRA SIGILLATA CERAMICS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mirguet, C.; Sciau, P.; Goudeau, P.

Different microscanning synchrotron techniques were used to better understand the elaboration process and origins of Terra Sigillata potteries from the Roman period. A mixture Gallic slip sample cross-section showing red and yellow colors was studied. The small (micron) size of the X-ray beam available at Stanford Synchrotron Radiation Laboratory (SSRL) and Advanced Light Source (ALS) synchrotron sources, coupled with the use of a sample scanning stage allowed us to spatially resolve the distribution of the constitutive mineral phases related to the chemical composition. Results show that red color is a result of iron-rich hematite crystals and the yellow part ismore » a result of the presence of Ti-rich rutile-type phase (brookite). Volcanic-type clay is at the origin of these marble Terra Sigillata.« less

Constraints on Dark Matter Annihilation by Synchrotron Emission based on Planck Data

NASA Astrophysics Data System (ADS)

Muanglay, Chalit; Wechakama, Maneenate; Cantlay, Brandon K.

2017-09-01

Synchrotron emission can be a good probe for dark matter particles in the Milky Way. We have investigated the production of electrons and positrons in the Milky Way within the context of dark matter annihilation. Upper limits on the relevant cross-section are obtained by comparing synchrotron emission in the microwave bands with Planck data. According to our results, the dark matter annihilation cross-section into electron-positron pairs should not be higher than the canonical value for a thermal relic if the mass of the dark matter candidate is smaller than a few GeV. In addition, we also look for constraints on the inner slope of dark matter density profile in the Milky Way. Our results indicate that the inner slope of dark matter profile is between 1 to 1.5.

UV-Visible Absorption Spectroscopy Enhanced X-ray Crystallography at Synchrotron and X-ray Free Electron Laser Sources.

PubMed

Cohen, Aina E; Doukov, Tzanko; Soltis, Michael S

2016-01-01

This review describes the use of single crystal UV-Visible Absorption micro-Spectrophotometry (UV-Vis AS) to enhance the design and execution of X-ray crystallography experiments for structural investigations of reaction intermediates of redox active and photosensitive proteins. Considerations for UV-Vis AS measurements at the synchrotron and associated instrumentation are described. UV-Vis AS is useful to verify the intermediate state of an enzyme and to monitor the progression of reactions within crystals. Radiation induced redox changes within protein crystals may be monitored to devise effective diffraction data collection strategies. An overview of the specific effects of radiation damage on macromolecular crystals is presented along with data collection strategies that minimize these effects by combining data from multiple crystals used at the synchrotron and with the X-ray free electron laser.

Mix-and-diffuse serial synchrotron crystallography

DOE PAGES

Beyerlein, Kenneth R.; Dierksmeyer, Dennis; Mariani, Valerio; ...

2017-10-09

Unravelling the interaction of biological macromolecules with ligands and substrates at high spatial and temporal resolution remains a major challenge in structural biology. The development of serial crystallography methods at X-ray free-electron lasers and subsequently at synchrotron light sources allows new approaches to tackle this challenge. Here, a new polyimide tape drive designed for mix-and-diffuse serial crystallography experiments is reported. The structure of lysozyme bound by the competitive inhibitor chitotriose was determined using this device in combination with microfluidic mixers. The electron densities obtained from mixing times of 2 and 50 s show clear binding of chitotriose to the enzymemore » at a high level of detail. Here, the success of this approach shows the potential for high-throughput drug screening and even structural enzymology on short timescales at bright synchrotron light sources.« less