Science.gov

Sample records for accelerator center represent

  1. Accelerated Schools: The Satellite Center Project.

    ERIC Educational Resources Information Center

    McCarthy, Jane

    The Accelerated Schools model attempts to restructure schools with high at-risk student populations and mainstream these students by the end of elementary school. A 6-year process of collaborative unity is used to identify challenge areas and move the school toward individualized solutions. The Accelerated Schools Satellite Center Project emerged…

  2. GPU accelerating technique for rendering implicitly represented vasculatures.

    PubMed

    Hong, Qingqi; Wang, Beizhan; Li, Qingde; Li, Yan; Wu, Qingqiang

    2014-01-01

    With the flooding datasets of medical Computed Tomography (CT) and Magnetic Resonance Imaging (MRI), implicit modeling techniques are increasingly applied to reconstruct the human organs, especially the vasculature. However, displaying implicitly represented geometric objects arises heavy computational burden. In this study, a Graphics Processing Unit (GPU) accelerating technique was developed for high performance rendering of implicitly represented objects, especially the vasculatures. The experimental results suggested that the rendering performance was greatly enhanced via exploiting the advantages of modern GPUs.

  3. LIONs at the Stanford Linear Accelerator Center

    SciTech Connect

    Constant, T.N.; Zdarko, R.W.; Simmons, R.H.; Bennett, B.M.

    1998-01-01

    The term LION is an acronym for Long Ionization Chamber. This is a distributed ion chamber which is used to monitor secondary ionization along the shield walls of a beam line resulting from incorrectly steered charged particle beams in lieu of the use of many discrete ion chambers. A cone of ionizing radiation emanating from a point source as a result of incorrect steering intercepts a portion of 1-5/8 inch Heliax cable (about 100 meters in length) filled with Argon gas at 20 psi and induces a pulsed current which is proportional to the ionizing charge. This signal is transmitted via the cable to an integrator circuit whose output is directed to an electronic comparators, which in turn is used to turn off the accelerated primary beam when preset limits are exceeded. This device is used in the Stanford Linear Accelerator Center (SLAC) Beam Containment System (BCS) to prevent potentially hazardous ionizing radiation resulting from incorrectly steered beams in areas that might be occupied by people. This paper describes the design parameters and experience in use in the Final Focus Test Beam (FFTB) area of the Stanford Linear Accelerator Center.

  4. Detector design studies for Turkish Accelerator Center

    NASA Astrophysics Data System (ADS)

    Aksu, Burçin; Piliçer, Ercan

    2017-02-01

    The proposed Particle Factory detector at Turkish Accelerator Center (TAC-PF) aims to search for charm physics, CP violation and mixing of D0 mesons as well as new physics effects by investigating head-on collisions of 1 GeV electron from Energy Recovery Linac (ERL) with 3.56 GeV positrons from synchrotron storage ring. In this work, we constructed the TAC-PF detector design by using a recently developed framework namely Detector Description for High Energy Physics (DD4hep). The baseline TAC-PF detector design and its qualifications were summarized, followed by a general description.

  5. Positron program at the Idaho Accelerator Center

    SciTech Connect

    Stancari, Giulio

    2009-09-02

    Positron physics is an important part of the research activities at the Idaho Accelerator Center (IAC). With positron annihilation spectroscopy, maps of nanodefects in materials have been obtained. For this purpose, positrons are generated by radioactive decay, photoactivation, or pair production. Preliminary tests of positron sources in the MeV range based on electron linacs have also been carried out at the IAC, and an expansion of this program is planned. A similar positron beam at Jefferson Lab would greatly improve our knowledge of the inner structure of the proton. In this paper, research with positrons at the IAC is reviewed. After a description of the Center's facilities, results from positron annihilation spectroscopy are discussed, together with future plans for testing a prototype positron source for CEBAF.

  6. Rail accelerator research at Lewis Research Center

    NASA Technical Reports Server (NTRS)

    Kerslake, W. R.; Cybyk, B. Z.

    1982-01-01

    A rail accelerator was chosen for study as an electromagnetic space propulsion device because of its simplicity and existing technology base. The results of a mission feasibility study using a large rail accelerator for direct launch of ton-size payloads from the Earth's surface to space, and the results of initial tests with a small, laboratory rail accelerator are presented. The laboratory rail accelerator has a bore of 3 by 3 mm and has accelerated 60 mg projectiles to velocities of 300 to 1000 m/s. Rail materials of Cu, W, and Mo were tested for efficiency and erosion rate.

  7. 28. REPRESENTATIVE CENTER WEDGE. BALANCE WHEELS ON TRACK, WITH RACK ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    28. REPRESENTATIVE CENTER WEDGE. BALANCE WHEELS ON TRACK, WITH RACK TO OUTSIDE, SHOWN TO RIGHT OF THE WEDGE. PHOTO TAKEN AT SOUTH SWING SPAN. - George P. Coleman Memorial Bridge, Spanning York River at U.S. Route 17, Yorktown, York County, VA

  8. Representing Audiences in Writing Center Consultation: A Discourse Analysis

    ERIC Educational Resources Information Center

    Brown, Robert

    2010-01-01

    One of the virtues of writing centers is that they compensate for the alienation of writing. If the canonical literate encounter is one where writer and reader meet only through the medium of the text, then the writing center consultation restores immediacy to written communication. Like an author-attended rehearsal, writing center consultation…

  9. 48 CFR 19.403 - Small Business Administration breakout procurement center representatives.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... procurement center representatives and technical advisors security clearances required by the contracting... business technical advisors. Assigned SBA breakout procurement center representatives and technical advisors are required to comply with the contracting agency's directives governing the conduct...

  10. 48 CFR 19.403 - Small Business Administration breakout procurement center representatives.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... procurement center representatives and technical advisors security clearances required by the contracting... business technical advisors. Assigned SBA breakout procurement center representatives and technical advisors are required to comply with the contracting agency's directives governing the conduct...

  11. 48 CFR 19.403 - Small Business Administration breakout procurement center representatives.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... procurement center representatives and technical advisors security clearances required by the contracting... business technical advisors. Assigned SBA breakout procurement center representatives and technical advisors are required to comply with the contracting agency's directives governing the conduct...

  12. 48 CFR 19.403 - Small Business Administration breakout procurement center representatives.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... procurement center representatives and technical advisors security clearances required by the contracting... business technical advisors. Assigned SBA breakout procurement center representatives and technical advisors are required to comply with the contracting agency's directives governing the conduct...

  13. Linac-Based Photonuclear Applications at the Idaho Accelerator Center

    NASA Astrophysics Data System (ADS)

    Mamtimin, Mayir; Starovoitova, Valeriia N.; Harmon, Frank

    2014-02-01

    In this paper, current Idaho Accelerator Center (IAC) activities based on the exploitation of high energy bremsstrahlung photons generated by linear electron accelerators will be reviewed. These beams are used to induce photonuclear interactions for a wide variety of applications in materials science, activation analysis, medical research, and nuclear technology. Most of the exploited phenomena are governed by the familiar giant dipole resonance cross section in nuclei. By proper target and converter design, optimization of photon and photoneutron production can be achieved, allowing radiation fields produced with both photons and neutrons to be used for medical isotope production and for fission product transmutation. The latter provides a specific application example that supports long-term fission product waste management. Using high-energy, highpower electron accelerators, we can demonstrate transmutation of radio-toxic, long-lived fission products (LLFP) such as 99Tc and 129I into short lived species. The latest experimental and simulation results will be presented.

  14. An organizational survey of the Stanford Linear Accelerator Center

    SciTech Connect

    Shurberg, D.A.; Haber, S.B.

    1991-11-01

    At the request of the Department of Energy, an Organizational Survey (OS) was administered at the Stanford Accelerator Center (SLAC). The OS measured employees` opinions on subjects such as organizational culture, communication, commitment, group cohesion, coordination, safety, environmental issues, and job satisfaction. The result of this work was a quantitative measure of the notion of culture at the SLAC site. This report presents these results and discusses their interpretation.

  15. Organizational cultural survey of the Stanford Linear Accelerator Center

    SciTech Connect

    Not Available

    1991-11-01

    At the request of the Department of Energy, an Organizational Survey (OS) was administered at the Stanford Accelerator Center (SLAC). The OS measured employees' opinions on subjects such as organizational culture, communication, commitment, group cohesion, coordination, safety, environmental issues, and job satisfaction. The result of this work was a quantitative measure of the notion of culture at the SLAC site. This report presents these results and discusses their interpretation.

  16. Organizational cultural survey of the Stanford Linear Accelerator Center

    SciTech Connect

    Not Available

    1991-11-01

    At the request of the Department of Energy, an Organizational Survey (OS) was administered at the Stanford Linear Accelerator Center (SLAC). The OS measured employees' opinions on subjects such as organizational culture, communication, commitment, group cohesion, coordination, safety, environmental issues, and job satisfaction. The result of this work was a quantitative measure of the notion of culture at the SLAC site. This report presents these results and discusses their interpretation.

  17. An organizational survey of the Stanford Linear Accelerator Center

    SciTech Connect

    Shurberg, D.A.; Haber, S.B.

    1991-11-01

    At the request of the Department of Energy, an Organizational Survey (OS) was administered at the Stanford Accelerator Center (SLAC). The OS measured employees' opinions on subjects such as organizational culture, communication, commitment, group cohesion, coordination, safety, environmental issues, and job satisfaction. The result of this work was a quantitative measure of the notion of culture at the SLAC site. This report presents these results and discusses their interpretation.

  18. 48 CFR 19.402 - Small Business Administration procurement center representatives.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... FEDERAL ACQUISITION REGULATION SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS Cooperation With the Small... representatives security clearances required by the contracting agency. (2) If a SBA procurement center... acquisition and security regulations, contracting officers shall give SBA procurement center...

  19. 48 CFR 19.403 - Small Business Administration breakout procurement center representatives.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... System FEDERAL ACQUISITION REGULATION SOCIOECONOMIC PROGRAMS SMALL BUSINESS PROGRAMS Cooperation With the... procurement center representatives and technical advisors security clearances required by the contracting... the level of such representative's approved security clearance classification; (6) Receive...

  20. The Galactic Center: A Petaelectronvolt Cosmic-ray Acceleration Factory

    NASA Astrophysics Data System (ADS)

    Guo, Yi-Qing; Tian, Zhen; Wang, Zhen; Li, Hai-Jin; Chen, Tian-Lu

    2017-02-01

    The multiteraelectronvolt γ-rays from the galactic center (GC) have a cutoff at tens of teraelectronvolts, whereas the diffuse emission has no such cutoff, which is regarded as an indication of petaelectronvolt proton acceleration by the HESS experiment. It is important to understand the inconsistency and study the possibility that petaelectronvolt cosmic-ray acceleration could account for the apparently contradictory point and diffuse γ-ray spectra. In this work, we propose that the cosmic rays are accelerated up to greater than petaelectronvolts in the GC. The interaction between cosmic rays and molecular clouds is responsible for the multiteraelectronvolt γ-ray emissions from both the point and diffuse sources today. Enhanced by the small volume filling factor (VFF) of the clumpy structure, the absorption of the γ-rays leads to a sharp cutoff spectrum at tens of teraelectronvolts produced in the GC. Away from the GC, the VFF grows, and the absorption enhancement becomes negligible. As a result, the spectra of γ-ray emissions for both point and diffuse sources can be successfully reproduced under such a self-consistent picture. In addition, a “surviving tail” at ∼100 TeV is expected from the point source, which can be observed by future projects CTA and LHAASO. Neutrinos are simultaneously produced during proton-proton (PP) collision. With 5–10 years of observations, the KM3Net experiment will be able to detect the petaelectronvolt source according to our calculation.

  1. 48 CFR 619.402 - Small Business Administration procurement center representatives.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Administration 619.402 Small Business Administration procurement center representatives. ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Small Business Administration procurement center representatives. 619.402 Section 619.402 Federal Acquisition Regulations...

  2. 48 CFR 19.402 - Small Business Administration procurement center representatives.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Business Administration 19.402 Small Business Administration procurement center representatives. (a)(1) The... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Small Business Administration procurement center representatives. 19.402 Section 19.402 Federal Acquisition Regulations...

  3. Tiger Team Assessment of the Stanford Linear Accelerator Center

    SciTech Connect

    Not Available

    1991-11-01

    This report documents the Tiger Team Assessment of the buildings, facilities, and activities at the Stanford Linear Accelerator Center (SLAC) and the Stanford Synchrotron Radiation Laboratory (SSRL) near San Francisco, California. SLAC/SSRL is the twenty-eighth DOE site to be assessed by a Tiger Team. SLAC and SSRL are single-purpose laboratories. SLAC is dedicated to experimental and theoretical research in elementary particle physics and to the development of new techniques in high-energy accelerators and elementary particle detectors. SSRL is dedicated to research in atomic and solid-state physics, chemistry, biology, and medicine. The purpose of the SLAC/SSRL Tiger Team Assessment is to provide the Secretary of Energy with concise information on the following: current ES&H compliance status at the site and the vulnerabilities associated with that compliance status; root causes for noncompliance; adequacy of DOE and SLAC/SSRL ES&H management programs; response actions to address identified problem areas; and effectiveness of self-assessment.

  4. Tiger Team Assessment of the Stanford Linear Accelerator Center

    SciTech Connect

    Not Available

    1991-11-01

    This report documents the Tiger Team Assessment of the buildings, facilities, and activities at the Stanford Linear Accelerator Center (SLAC) and the Stanford Synchrotron Radiation Laboratory (SSRL) near San Francisco, California. SLAC/SSRL is the twenty-eighth DOE site to be assessed by a Tiger Team. SLAC and SSRL are single-purpose laboratories. SLAC is dedicated to experimental and theoretical research in elementary particle physics and to the development of new techniques in high-energy accelerators and elementary particle detectors. SSRL is dedicated to research in atomic and solid-state physics, chemistry, biology, and medicine. The purpose of the SLAC/SSRL Tiger Team Assessment is to provide the Secretary of Energy with concise information on the following: current ES H compliance status at the site and the vulnerabilities associated with that compliance status; root causes for noncompliance; adequacy of DOE and SLAC/SSRL ES H management programs; response actions to address identified problem areas; and effectiveness of self-assessment.

  5. The ADVANCE network: accelerating data value across a national community health center network

    PubMed Central

    DeVoe, Jennifer E; Gold, Rachel; Cottrell, Erika; Bauer, Vance; Brickman, Andrew; Puro, Jon; Nelson, Christine; Mayer, Kenneth H; Sears, Abigail; Burdick, Tim; Merrell, Jonathan; Matthews, Paul; Fields, Scott

    2014-01-01

    The ADVANCE (Accelerating Data Value Across a National Community Health Center Network) clinical data research network (CDRN) is led by the OCHIN Community Health Information Network in partnership with Health Choice Network and Fenway Health. The ADVANCE CDRN will ‘horizontally’ integrate outpatient electronic health record data for over one million federally qualified health center patients, and ‘vertically’ integrate hospital, health plan, and community data for these patients, often under-represented in research studies. Patient investigators, community investigators, and academic investigators with diverse expertise will work together to meet project goals related to data integration, patient engagement and recruitment, and the development of streamlined regulatory policies. By enhancing the data and research infrastructure of participating organizations, the ADVANCE CDRN will serve as a ‘community laboratory’ for including disadvantaged and vulnerable patients in patient-centered outcomes research that is aligned with the priorities of patients, clinics, and communities in our network. PMID:24821740

  6. Turkish Accelerator Center (TAC) Project: Status and Regional Importance

    SciTech Connect

    Yavas, Oe.

    2010-01-21

    The Turkish Accelerator Center (TAC) Project was started in 1997 with support of the State Planning Organization (SPO) of Turkey under Ankara University's coordination. After completing Feasibility Report (FR, 2000) and Conceptual Design Repot (CDR, 2005), third phase of the project was started in 2006 as an inter-university project with support of SPO. Third phase of the project has two main scientific goals: to write Technical Design Report (TDR) of TAC and to establish an Infrared Free Electron Laser (IR FEL) facility as a first step. The first facility and TDR studies are planned to be completed in 2012. Construction phase of TAC will cover 2013-2023. TAC collaboration include ten Turkish Universities: Ankara, Gazi, Istanbul, Bogazici, Dogus, Uludag, Dumlupmar, Nigde, Erciyes and S. Demirel Universities. It was planned that the first facility will be an IR FEL and Bremsstrahlung laboratory based on 15-40 MeV electron linac and two optical cavities with 2.5 and 9 cm undulators to scan 2-250 microns wavelength range. Main purpose of the facility is to use IR FEL for research in material science, nonlinear optics, semiconductors, biotechnology, medicine and photochemical processes. In this study; aims, regional importance, main parts and main parameters of TAC and TAC IR FEL and Bremsstrahlung facility are explained. Road map of the TAC project is given. National and international collaborations are explained.

  7. Environmental Survey preliminary report, Stanford Linear Accelerator Center, Stanford, California

    SciTech Connect

    Not Available

    1988-07-01

    This report presents the preliminary findings from the first phase of the Survey of the US Department of Energy (DOE) Stanford Linear Accelerator Center (SLAC) at Stanford, California, conducted February 29 through March 4, 1988. The Survey is being conducted by an interdisciplinary team of environmental specialists, led and managed by the Office of Environment, Safety and Health's Office of Environmental Audit. Individual team components are being supplied by a private contractor. The objective of the Survey is to identify environmental problems and areas of environmental risk associated with the SLAC. The Survey covers all environmental media and all areas of environmental regulation and is being performed in accordance with the DOE Environmental Survey Manual. This phase of the Survey involves the review of existing site environmental data, observations of the operations at the SLAC, and interviews with site personnel. The Survey team is developing a Sampling and Analysis Plan to assist in further assessing certain of the environmental problems identified during its on-site activities. The Sampling and Analysis Plan will be executed by a DOE National Laboratory or a support contractor. When completed, the results will be incorporated into the Environmental Survey Interim Report for the SLAC facility. The Interim Report will reflect the final determinations of the SLAC Survey. 95 refs., 25 figs., 25 tabs.

  8. Turkish Accelerator Center (TAC) Project: Status and Regional Importance

    NASA Astrophysics Data System (ADS)

    Yavaş, Ö.

    2010-01-01

    The Turkish Accelerator Center (TAC) Project was started in 1997 with support of the State Planning Organization (SPO) of Turkey under Ankara University's coordination. After completing Feasibility Report (FR, 2000) and Conceptual Design Repot (CDR, 2005), third phase of the project was started in 2006 as an inter-university project with support of SPO. Third phase of the project has two main scientific goals: to write Technical Design Report (TDR) of TAC and to establish an Infrared Free Electron Laser (IR FEL) facility as a first step. The first facility and TDR studies are planned to be completed in 2012. Construction phase of TAC will cover 2013-2023. TAC collaboration include ten Turkish Universities: Ankara, Gazi, İstanbul, Boğaziçi, Doğuş, Uludağ, Dumlupmar, Niğde, Erciyes and S. Demirel Universities. It was planned that the first facility will be an IR FEL & Bremsstrahlung laboratory based on 15-40 MeV electron linac and two optical cavities with 2.5 and 9 cm undulators to scan 2-250 microns wavelength range. Main purpose of the facility is to use IR FEL for research in material science, nonlinear optics, semiconductors, biotechnology, medicine and photochemical processes. In this study; aims, regional importance, main parts and main parameters of TAC and TAC IR FEL & Bremsstrahlung facility are explained. Road map of the TAC project is given. National and international collaborations are explained.

  9. Energy Frontier Research Centers: A View from Senior EFRC Representatives (2011 EFRC Summit, panel session)

    ScienceCinema

    Drell, Persis (SLAC); Armstrong, Neal (University of Arizona); Carter, Emily (Princeton University); DePaolo, Don (Lawrence Berkeley National Laboratory); Gunnoe, Brent (University of Virginia)

    2016-07-12

    A distinguished panel of scientists from the EFRC community provide their perspective on the importance of EFRCs for addressing critical energy needs at the 2011 EFRC Summit. Persis Drell, Director at SLAC, served as moderator. Panel members are Neal Armstrong (Director of the Center for Interface Science: Solar Electric Materials, led by the University of Arizona), Emily Carter (Co-Director of the Combustion EFRC, led by Princeton University. She is also Team Leader of the Heterogeneous Functional Materials Center, led by the University of South Caroline), Don DePaolo (Director of the Center for Nanoscale Control of Geologic CO2, led by LBNL), and Brent Gunnoe (Director of the Center for Catalytic Hydrocarbon Functionalization, led by the University of Virginia). The 2011 EFRC Summit and Forum brought together the EFRC community and science and policy leaders from universities, national laboratories, industry and government to discuss "Science for our Nation's Energy Future." In August 2009, the Office of Science established 46 Energy Frontier Research Centers. The EFRCs are collaborative research efforts intended to accelerate high-risk, high-reward fundamental research, the scientific basis for transformative energy technologies of the future. These Centers involve universities, national laboratories, nonprofit organizations, and for-profit firms, singly or in partnerships, selected by scientific peer review. They are funded at $2 to $5 million per year for a total planned DOE commitment of $777 million over the initial five-year award period, pending Congressional appropriations. These integrated, multi-investigator Centers are conducting fundamental research focusing on one or more of several “grand challenges” and use-inspired “basic research needs” recently identified in major strategic planning efforts by the scientific community. The purpose of the EFRCs is to integrate the talents and expertise of leading scientists in a setting

  10. Solving the problem of negative populations in approximate accelerated stochastic simulations using the representative reaction approach.

    PubMed

    Kadam, Shantanu; Vanka, Kumar

    2013-02-15

    Methods based on the stochastic formulation of chemical kinetics have the potential to accurately reproduce the dynamical behavior of various biochemical systems of interest. However, the computational expense makes them impractical for the study of real systems. Attempts to render these methods practical have led to the development of accelerated methods, where the reaction numbers are modeled by Poisson random numbers. However, for certain systems, such methods give rise to physically unrealistic negative numbers for species populations. The methods which make use of binomial variables, in place of Poisson random numbers, have since become popular, and have been partially successful in addressing this problem. In this manuscript, the development of two new computational methods, based on the representative reaction approach (RRA), has been discussed. The new methods endeavor to solve the problem of negative numbers, by making use of tools like the stochastic simulation algorithm and the binomial method, in conjunction with the RRA. It is found that these newly developed methods perform better than other binomial methods used for stochastic simulations, in resolving the problem of negative populations.

  11. The polarized electron source of the Stanford Linear Accelerator Center

    SciTech Connect

    Schultz, D.; Alley, R.; Clendenin, J.; Frisch, J.; Mulhollan, G.; Saez, P.; Tang, H.; Witte, K.

    1994-08-01

    The Stanford Linear Accelerator has been running with polarized electrons both in the collider (SLC) mode and in the fixed target mode. The accelerators polarized electron source is based on a thin, strained GaAs photocathode, which is held at a negative high voltage and illuminated by a Titanium Sapphire laser. The reliability of the source was better than 95% during the eight-month-long 1993 SLC run. A beam polarization of 63% was measured by the SLD experiment at the SLC interaction point in the 1993 data run. The fixed-target experiment E143 measured a beam polarization of 85% in its 1993--94 run. These polarization measurements, made at high energy, are in good agreement with measurements made at low energy on a calibrated Mott polarimeter. The higher beam polarization in the fixed target experiment is due to a thinner, more highly strained GaAs photocathode than had been used earlier, and to the experiment`s low beam current requirements. The SLC is now running with the high polarization photocathode. Details of the source, and experience with the high polarization strained GaAs photocathodes on the accelerator in the current SLC run, will be presented.

  12. Evaluation of Dosimetric Consequences of Seroma Contour Variability in Accelerated Partial Breast Irradiation Using a Constructed Representative Seroma Contour

    SciTech Connect

    Kosztyla, Robert; Olson, Robert; Carolan, Hannah; Balkwill, Susan; Moiseenko, Vitali; Kwan, Winkle

    2012-10-01

    Purpose: Contouring variability of the seroma can have important implications in the planning and delivery of accelerated partial breast irradiation (APBI). This study aimed to quantify the dosimetric impact of these interobserver and intraobserver contouring variations by construction of a representative seroma contour (RSC). Methods and Materials: Twenty-one patients with a seroma suitable for APBI underwent four computed tomography (CT) scans: one planning CT and three additional CTs on the first, third, and fifth days of treatment. Three radiation oncologists contoured the seroma on each CT scan. For 3 patients, oncologists repeated contouring twice to assess intraobserver variations. Seroma contour variability was quantified by construction of an RSC. In addition, the percent volume overlap (PVO) was calculated. Root-mean-square (RMS) differences in seroma volume, size, and center of mass position compared to those of the RSC were calculated. Treatment fields from the original plan were applied to the repeated CTs by using the same isocenter shifts as the original plan. The dosimetric impact of the contour variations was assessed using V{sub 95} (volume receiving at least 95% of the prescribed dose) and equivalent uniform dose (EUD). Results: Interobserver RMS volume differences were, on average, 5.6 times larger than intraobserver differences. The median interobserver RMS seroma volume difference was 1.48 cm{sup 3}. The median PVO was 51.6%. V{sub 95} and EUD of the seroma contours were similar for all patients. The median RMS differences of the seroma V{sub 95} and EUD were 0.01% (range, 0%-3.99%) and 0.05 Gy (range, 0-0.98 Gy). Conclusions: Construction of the RSC showed that interobserver variations were most responsible for contour variations of the seroma. Current planning margins provided adequate dose coverage of the seroma despite these contour variations.

  13. Developments and applications of accelerator system at the Wakasa Wan Energy Research Center

    NASA Astrophysics Data System (ADS)

    Hatori, S.; Kurita, T.; Hayashi, Y.; Yamada, M.; Yamada, H.; Mori, J.; Hamachi, H.; Kimura, S.; Shimoda, T.; Hiroto, M.; Hashimoto, T.; Shimada, M.; Yamamoto, H.; Ohtani, N.; Yasuda, K.; Ishigami, R.; Sasase, M.; Ito, Y.; Hatashita, M.; Takagi, K.; Kume, K.; Fukuda, S.; Yokohama, N.; Kagiya, G.; Fukumoto, S.; Kondo, M.

    2005-12-01

    At the Wakasa Wan Energy Research Center (WERC), an accelerator system with a 5 MV tandem accelerator and a 200 MeV proton synchrotron is used for ion beam analyses and irradiation experiments. The study of cancer therapy with a proton beam is also performed. Therefore, the stable operation and efficient sharing of beam time of the system are required, based on the treatment standard. Recent developments and the operation status of the system put stress on the tandem accelerator operation, magnifying the problems.

  14. Pre-Implementation and Performance Plan for the Latino Development and Technology Accelerator Center

    SciTech Connect

    Quiroga, Marcelo

    2007-03-30

    This report discusses the Latino Development and Technology Accelerator Center (Center) and its innovative economic development program. The chapters describe the organization and the operations of a two-pillar model for training and business acceleration and how the program focuses on the economic development of a disadvantaged Chicago, Illinois, Hispanic community located in Humboldt Park. The Humboldt Park community is located 3 miles west of Chicago's affluent downtown. Humboldt Park residents have income levels below the poverty line and unemployment rates twice the national average.

  15. Sensitivity Upgrades to the Idaho Accelerator Center Neutron Time of Flight Spectrometer

    SciTech Connect

    Thompson, S. J.; Kinlaw, M. T.; Harmon, J. F.; Wells, D. P.; Hunt, A. W.

    2007-10-26

    Past experiments have shown that discrimination between between fissionable and non-fissionable materials is possible using an interrogation technique that monitors for high energy prompt fission neutrons. Several recent upgrades have been made to the neutron time of flight spectrometer at the Idaho Accelerator Center with the intent of increasing neutron detection sensitivity, allowing for system use in nonproliferation and security applications.

  16. Natural and Accelerated Bioremediation Research (NABIR) Field Research Center (FRC) Management Plan

    SciTech Connect

    Watson, D.B.

    2002-02-28

    The Environmental Sciences Division at Oak Ridge National Laboratory has established a Field Research Center (FRC) to support the Natural and Accelerated Bioremediation Research (NABIR) Program on the U.S. Department of Energy (DOE) Oak Ridge Reservation in Oak Ridge, Tennessee for the DOE Headquarters Office of Biological and Environmental Research within the Office of Science.

  17. DYNAMICS: Teaching the Concepts of Acceleration Center and Virtual Work in Dynamics.

    ERIC Educational Resources Information Center

    Jong, I. C.; Rogers, B. G.

    1989-01-01

    The main advantage of using these concepts lies in the reduction of algebraic work involved in solving certain dynamics problems. A brief analytical treatment of the acceleration center and a description of a virtual work principle for equipollent systems in the kinetics of rigid bodies are provided. (MVL)

  18. (Stanford Linear Accelerator Center) annual environmental monitoring report, January--December 1989

    SciTech Connect

    Not Available

    1990-05-01

    This progress report discusses environmental monitoring activities at the Stanford Linear Accelerator Center for 1989. Topics include climate, site geology, site water usage, land use, demography, unusual events or releases, radioactive and nonradioactive releases, compliance summary, environmental nonradiological program information, environmental radiological program information, groundwater protection monitoring ad quality assurance. 5 figs., 7 tabs. (KJD)

  19. Impact of Center-of-Mass Acceleration on the Performance of Ultramarathon Runners

    PubMed Central

    Lin, Shun-Ping; Sung, Wen-Hsu; Kuo, Fon-Chu; Kuo, Terry B.J.; Chen, Jin-Jong

    2014-01-01

    Ultramarathon races are rapidly gaining popularity in several countries, raising interest for the improvement of training programs. The aim of this study was to use a triaxial accelerometer to compare the three-dimensional center-of-mass accelerations of two groups of ultramarathon runners with distinct performances during different running speeds and distances. Ten runners who participated in the 12-h Taipei International Ultramarathon Race underwent laboratory treadmill testing one month later. They were divided into an elite group (EG; n = 5) and a sub-elite group (SG; n = 5). The triaxial center-of-mass acceleration recorded during a level-surface progressive intensity running protocol (3, 6, 8, 9, 10, and 12 km/h; 5 min each) was used for correlation analyses with running distance during the ultramarathon. The EG showed negative correlations between mediolateral (ML) acceleration (r = −0.83 to −0.93, p < 0.05), and between anterior–posterior (AP) acceleration and running distance (r = −0.8953 to −0.9653, p < 0.05), but not for vertical control of the center of mass. This study suggests that runners reduce stride length to minimize mediolateral sway and the effects of braking on the trunk; moreover, cadence must be increased to reduce braking effects and enhance impetus. Consequently, the competition level of ultramarathons can be elevated. PMID:25713664

  20. Use of accelerating clinical improvement in reorganization of care: the Dartmouth-Hitchcock Medical Center experience.

    PubMed

    Kobokovich, L J

    1997-01-01

    Accelerating clinical improvement is a unique strategic method for accelerating the rate and effectiveness of improvements in strategically important clinical services. It promotes real reduction in the cost of service while preserving the quality and value within the system. Based on the components of process, value, benchmarking, change, and learning, the method can be used in any system or setting to produce value-driven change. Accelerating clinical improvement is being used within the Obstetrical Department of Dartmouth-Hitchcock Medical Center to decrease postpartum length of stay for families with spontaneous vaginal delivery. Familiarity with the method led to additional and ongoing improvements in the system. This method is important for nurses because it is continuous, multidisciplinary, addresses values of concern to families and providers, and is easily incorporated by nurse providers in any clinical setting.

  1. Exploring defocus matting: nonparametric acceleration, super-resolution, and off-center matting.

    PubMed

    Joshi, Neel; Matusik, Wojciech; Avidan, Shai; Pfister, Hanspeter; Freeman, William T

    2007-01-01

    Defocus matting is a fully automatic and passive method for pulling mattes from video captured with coaxial cameras that have different depths of field and planes of focus. Nonparametric sampling can accelerate the video-matting process from minutes to seconds per frame. In addition a super-resolution technique efficiently bridges the gap between mattes from high-resolution video cameras and those from low-resolution cameras. Off-center matting pulls mattes for an external high-resolution camera that doesn't share the same center of projection as the low-resolution cameras used to capture the defocus matting data.

  2. Center of pressure velocity reflects body acceleration rather than body velocity during quiet standing.

    PubMed

    Masani, Kei; Vette, Albert H; Abe, Masaki O; Nakazawa, Kimitaka

    2014-03-01

    The purpose of this study was to test the hypothesis that the center of pressure (COP) velocity reflects the center of mass (COM) acceleration due to a large derivative gain in the neural control system during quiet standing. Twenty-seven young (27.2±4.5 years) and twenty-three elderly (66.2±5.0 years) subjects participated in this study. Each subject was requested to stand quietly on a force plate for five trials, each 90 s long. The COP and COM displacements, the COP and COM velocities, and the COM acceleration were acquired via a force plate and a laser displacement sensor. The amount of fluctuation of each variable was quantified using the root mean square. Following the experimental study, a simulation study was executed to investigate the experimental findings. The experimental results revealed that the COP velocity was correlated with the COM velocity, but more highly correlated with the COM acceleration. The equation of motion of the inverted pendulum model, however, accounts only for the correlation between the COP and COM velocities. These experimental results can be meaningfully explained by the simulation study, which indicated that the neural motor command presumably contains a significant portion that is proportional to body velocity. In conclusion, the COP velocity fluctuation reflects the COM acceleration fluctuation rather than the COM velocity fluctuation, implying that the neural motor command controlling quiet standing posture contains a significant portion that is proportional to body velocity.

  3. The Dust Accelerator Facility of the Colorado Center for Lunar Dust and Atmospheric Studies

    SciTech Connect

    Horanyi, M.; Colette, A.; Drake, K.; Gruen, E.; Kempf, S.; Munsat, T.; Robertson, S.; Shu, A.; Sternovsky, Z.; Wang, X.

    2011-11-29

    The NASA Lunar Institute's Colorado Center for Lunar Dust and Atmospheric Studies has recently completed the construction of a new experimental facility to study hypervelocity dust impacts. The installation includes a 3 MV Pelletron, accelerating small particles in the size range of 0.1 to few microns to velocities in the range of 1 to 100 km/s. Here we report the capabilities of our facility, and the results of our first experiments.

  4. Center of Mass Acceleration Feedback Control for Standing by Functional Neuromuscular Stimulation – a Simulation Study

    PubMed Central

    Audu, Musa L.; Kirsch, Robert F.; Triolo, Ronald J.

    2013-01-01

    The potential efficacy of total body center of mass (COM) acceleration for feedback control of standing balance by functional neuromuscular stimulation (FNS) following spinal cord injury (SCI) was investigated. COM acceleration may be a viable alternative to conventional joint kinematics due to its rapid responsiveness, focal representation of COM dynamics, and ease of measurement. A computational procedure was developed using an anatomically-realistic, three-dimensional, bipedal biomechanical model to determine optimal patterns of muscle excitations to produce targeted effects upon COM acceleration from erect stance. The procedure was verified with electromyographic data collected from standing able-bodied subjects undergoing systematic perturbations. Using 16 muscle groups targeted by existing implantable neuroprostheses, data were generated to train an artificial neural network (ANN)-based controller in simulation. During forward simulations, proportional feedback of COM acceleration drove the ANN to produce muscle excitation patterns countering the effects of applied perturbations. Feedback gains were optimized to minimize upper extremity (UE) loading required to stabilize against disturbances. Compared to the clinical case of maximum constant excitation, the controller reduced UE loading by 43% in resisting external perturbations and by 51% during simulated one-arm reaching. Future work includes performance assessment against expected measurement errors and developing user-specific control systems. PMID:22773529

  5. A history of thyratron lifetimes at the Stanford Linear Accelerator Center

    SciTech Connect

    Ficklin, D.B. Jr.

    1994-12-01

    The Stanford Linear Accelerator Center (SLAC) has been in almost continuous operation since the middle 1960s, providing a remarkable opportunity to amass thyratron data. This paper reviews the history of this thyratron usage, focusing primarily on data collected during the last ten years of accelerator operation. There have been two distinct operating conditions during the history of operation at SLAC. Prior to 1985, the fundamental thyratron operating points were 46 kV anode voltage (Epy), 4.2 kA peak current, 3.8 {mu}s equivalent square pulse (esp), with a maximum repetition rate of 360 pulses per second (pps). The accelerator was upgraded during 1985, and the thyratron operating points are now 46 kV Epy, 6.3 kA, 5.4 {mu}s esp, with a maximum repetition rate of 120 pps. The SLAC high-energy physics research program requires that each of the available modulator klystron units provide a stable microwave energy source. Within these constraints, this paper explores historical thyratron lifetimes at SLAC, reviewing the available data to determine how long these thyratrons can be expected to operate before failure currently or recently used in the 243 accelerator modulators.

  6. Radiation Safety System of the B-Factory at the Stanford Linear Accelerator Center

    SciTech Connect

    Liu, James C.

    1998-10-12

    The radiation safety system (RSS) of the B-Factory accelerator facility at the Stanford Linear Accelerator Center (SLAC) is described. The RSS, which is designed to protect people from prompt radiation exposure due to beam operation, consists of the access control system (ACS) and the radiation containment system (RCS). The ACS prevents people from being exposed to the very high radiation levels inside a beamline shielding housing. The ACS consists of barriers, a standard entry module at every entrance, and beam stoppers. The RCS prevents people from being exposed to the radiation outside a shielding housing, due to either normal or abnormal operation. The RCS consists of power limiting devices, shielding, dump/collimator, and an active radiation monitor system. The inter-related system elements for the ACS and RCS, as well as the associated interlock network, are described. The policies and practices in setting up the RSS are also compared with the regulatory requirements.

  7. High energy focused ion beam technology and applications at the Louisiana Accelerator Center

    NASA Astrophysics Data System (ADS)

    Glass, G. A.; Dymnikov, A. D.; Rout, B.; Zachry, D. P.

    2007-07-01

    The high energy focused ion beam (HEFIB) system at the Louisiana Accelerator Center (LAC) of the University of Louisiana at Lafayette, Lafayette, USA, is constructed on one of the beamlines of a National Electrostatics Corporation 1.7 MV 5SDH-2 tandem accelerator. The HEFIB system has several components, including a versatile magnetic quadrupole sextuplet lens focusing system defined as the Russian magnetic sextuplet (RMS) system having the same demagnifications, the same focal lengths and the same positions of the focal points in xz and yz planes as the Russian quadruplet and a one-piece concrete supporting base and integrated endstation with air isolation. A review of recent microlithography and HEFIB system developments at LAC are presented, as well as new results using heavy ion (HI) beam lithography on crystalline silicon.

  8. 3 MV hypervelocity dust accelerator at the Colorado Center for Lunar Dust and Atmospheric Studies.

    PubMed

    Shu, Anthony; Collette, Andrew; Drake, Keith; Grün, Eberhard; Horányi, Mihály; Kempf, Sascha; Mocker, Anna; Munsat, Tobin; Northway, Paige; Srama, Ralf; Sternovsky, Zoltán; Thomas, Evan

    2012-07-01

    A hypervelocity dust accelerator for studying micrometeorite impacts has been constructed at the Colorado Center for Lunar Dust and Atmospheric Studies (CCLDAS) at the University of Colorado. Based on the Max-Planck-Institüt für Kernphysik (MPI-K) accelerator, this accelerator is capable of emitting single particles of a specific mass and velocity selected by the user. The accelerator consists of a 3 MV Pelletron generator with a dust source, four image charge pickup detectors, and two interchangeable target chambers: a large high-vacuum test bed and an ultra-high vacuum impact study chamber. The large test bed is a 1.2 m diameter, 1.5 m long cylindrical vacuum chamber capable of pressures as low as 10(-7) torr while the ultra-high vacuum chamber is a 0.75 m diameter, 1.1 m long chamber capable of pressures as low as 10(-10) torr. Using iron dust of up to 2 microns in diameter, final velocities have been measured up to 52 km/s. The spread of the dust particles and the effect of electrostatic focusing have been measured using a long exposure CCD and a quartz target. Furthermore, a new technique of particle selection is being developed using real time digital filtering techniques. Signals are digitized and then cross-correlated with a shaped filter, resulting in a suppressed noise floor. Improvements over the MPI-K design, which include a higher operating voltage and digital filtering for detection, increase the available parameter space of dust emitted by the accelerator. The CCLDAS dust facility is a user facility open to the scientific community to assist with instrument calibrations and experiments.

  9. 3 MV hypervelocity dust accelerator at the Colorado Center for Lunar Dust and Atmospheric Studies

    SciTech Connect

    Shu, Anthony; Horanyi, Mihaly; Kempf, Sascha; Thomas, Evan; Collette, Andrew; Drake, Keith; Northway, Paige; Gruen, Eberhard; Mocker, Anna; Munsat, Tobin; Srama, Ralf; and others

    2012-07-15

    A hypervelocity dust accelerator for studying micrometeorite impacts has been constructed at the Colorado Center for Lunar Dust and Atmospheric Studies (CCLDAS) at the University of Colorado. Based on the Max-Planck-Instituet fuer Kernphysik (MPI-K) accelerator, this accelerator is capable of emitting single particles of a specific mass and velocity selected by the user. The accelerator consists of a 3 MV Pelletron generator with a dust source, four image charge pickup detectors, and two interchangeable target chambers: a large high-vacuum test bed and an ultra-high vacuum impact study chamber. The large test bed is a 1.2 m diameter, 1.5 m long cylindrical vacuum chamber capable of pressures as low as 10{sup -7} torr while the ultra-high vacuum chamber is a 0.75 m diameter, 1.1 m long chamber capable of pressures as low as 10{sup -10} torr. Using iron dust of up to 2 microns in diameter, final velocities have been measured up to 52 km/s. The spread of the dust particles and the effect of electrostatic focusing have been measured using a long exposure CCD and a quartz target. Furthermore, a new technique of particle selection is being developed using real time digital filtering techniques. Signals are digitized and then cross-correlated with a shaped filter, resulting in a suppressed noise floor. Improvements over the MPI-K design, which include a higher operating voltage and digital filtering for detection, increase the available parameter space of dust emitted by the accelerator. The CCLDAS dust facility is a user facility open to the scientific community to assist with instrument calibrations and experiments.

  10. Trying differently: A relationship-centered approach to representing clients with cognitive challenges.

    PubMed

    Boulding, David M; Brooks, Susan L

    2010-01-01

    This article demonstrates the usefulness of an innovative framework called "Relationship-Centered Lawyering" to enhancing real world legal practice. It uses the example of lawyers, particularly criminal defense lawyers, who often deal with clients with cognitive challenges. The article developed out of a series of workshops conducted jointly by the co-authors, an American law professor with a social work background, and a Canadian criminal defense lawyer and family mediator who is an international expert on Fetal Alcohol Spectrum Disorder and other Neuro-Behavioral Disorders (FA/NB). The paper describes the relational theory Brooks developed (along with Robert Madden), along with the science of cognitive impairments, with a specific focus on FA/NB. The paper provides two illustrations of the relational framework by explaining Boulding's strategy of creating what is called the "external brain" and his techniques of relational interviewing.

  11. Transverse Beam Emittance Measurements of a 16 MeV Linac at the Idaho Accelerator Center

    SciTech Connect

    S. Setiniyaz, T.A. Forest, K. Chouffani, Y. Kim, A. Freyberger

    2012-07-01

    A beam emittance measurement of the 16 MeV S-band High Repetition Rate Linac (HRRL) was performed at Idaho State University's Idaho Accelerator Center (IAC). The HRRL linac structure was upgraded beyond the capabilities of a typical medical linac so it can achieve a repetition rate of 1 kHz. Measurements of the HRRL transverse beam emittance are underway that will be used to optimize the production of positrons using HRRL's intense electron beam on a tungsten converter. In this paper, we describe a beam imaging system using on an OTR screen and a digital CCD camera, a MATLAB tool to extract beamsize and emittance, detailed measurement procedures, and the measured transverse emittances for an arbitrary beam energy of 15 MeV.

  12. Accelerating Energy Efficiency in Indian Data Centers. Final Report for Phase I Activities

    SciTech Connect

    Ganguly, Suprotim; Raje, Sanyukta; Kumar, Satish; Sartor, Dale; Greenberg, Steve

    2016-01-01

    This report documents Phase 1 of the “Accelerating Energy Efficiency in Indian Data Centers” initiative to support the development of an energy efficiency policy framework for Indian data centers. The initiative is being led by the Confederation of Indian Industry (CII), in collaboration with Lawrence Berkeley National Laboratory (LBNL)-U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy, and under the guidance of Bureau of Energy Efficiency (BEE). It is also part of the larger Power and Energy Efficiency Working Group of the US-India Bilateral Energy Dialogue. The initiative consists of two phases: Phase 1 (November 2014 – September 2015) and Phase 2 (October 2015 – September 2016).

  13. A new world of biomedical research - the Center for Accelerator Mass Spectrometry

    SciTech Connect

    Holloway, C.

    1997-11-01

    Lawrence Livermore`s Center for Accelerator Mass Spectrometry (AMS) is one of the leading AMS facilities in the world, performing about 25% of all AMS analyses. It is also at the forefront of the emerging field of AMS as applied to biomedical research. AMS is so sensitive that it can identify just a few molecules of a substance among trillions of molecules. This sensitivity makes possible for the first time the study of toxins, dietary nutrients, drugs, and other substances in dosages that are relevant to humans. Work with volunteer subjects indicates that a chemical that is produced when meat is cooked adversely affects human DNA more than it does the DNA of laboratory animals. This research supports the need to pursue additional human biological risk assessment using AMS. Livermore is also performing studies of the human metabolism of calcium, which are difficult without AMS.

  14. The Family Medicine Accelerated Track at Texas Tech University Health Sciences Center.

    PubMed

    Jones, Betsy Goebel; Berk, Steven L

    2016-02-01

    Meeting Texas' future health care needs will be challenging, including the goal for a physician workforce more balanced toward primary care. To help expand the primary care physician workforce, Texas Tech University Health Sciences Center (TTUHSC) School of Medicine developed the Family Medicine Accelerated Track (FMAT), a three-year curriculum that culminates in the MD degree and links medical students to family medicine residency programs at TTUHSC campuses in Lubbock, Amarillo, or the Permian Basin (Odessa and Midland). Twenty current family medicine residents are graduates of the FMAT program, and 30 medical students are enrolled in the program, which is charting a path for curricular innovation in medical education that will be increasingly competency-based.

  15. The development of seismic guidelines for the Stanford Linear Accelerator Center

    SciTech Connect

    Huggins, R.

    1996-08-01

    This paper describes the development of Seismic Guidelines for the Stanford Linear Accelerator Center (SLAC). Although structures have always been built conservatively, SLAC management decided to review and update their seismic guidelines. SLAC is about mid-way between the epicenters of the 8.3 Richter magnitude 1906 San Francisco and the 7.2 Loma Prieta Earthquakes. The west end of the two mile long electron/positron particle accelerator lies a half mile from the large San Andreas Fault. Suggestions for seismic planning processes were solicited from local computer manufacturing firms, universities, and federal laboratories. A Committee of the various stakeholders in SLAC`s seismic planning retained an internationally known Seismic Planning Consultant and reviewed relevant standards and drafted Guidelines. A panel of seismic experts was convened to help define the hazard, site response spectra, probabilistic analysis of shaking, and near field effects. The Facility`s structures were assigned to seismic classes of importance, and an initial assessment of a sample of a dozen buildings conducted. This assessment resulted in emergency repairs to one structure, and provided a {open_quotes}reality basis{close_quotes} for establishing the final Guidelines and Administrative Procedures, and a program to evaluate remaining buildings, shielding walls, tunnels, and other special structures.

  16. Representing Value as Digital Object: A Discussion of Transferability and Anonymity; Digital Library Initiatives of the Deutsche Forschungsgemeinschaft; CrossRef Turns One; Fermi National Accelerator Laboratory (Fermilab).

    ERIC Educational Resources Information Center

    Kahn, Robert E.; Lyons, Patrice A.; Brahms, Ewald; Brand, Amy; van den Bergen, Mieke

    2001-01-01

    Includes four articles that discuss the use of digital objects to represent value in a network environment; digital library initiatives at the central public funding organization for academic research in Germany; an application of the Digital Object Identifier System; and the Web site of the Fermi National Accelerator Laboratory. (LRW)

  17. Radiation Pressure Forces, the Anomalous Acceleration, and Center of Mass Motion for the TOPEX/POSEIDON Spacecraft

    NASA Technical Reports Server (NTRS)

    Kubitschek, Daniel G.; Born, George H.

    2000-01-01

    Shortly after launch of the TOPEX/POSEIDON (T/P) spacecraft (s/c), the Precision Orbit Determination (POD) Team at NASA's Goddard Space Flight Center (GSFC) and the Center for Space Research at the University of Texas, discovered residual along-track accelerations, which were unexpected. Here, we describe the analysis of radiation pressure forces acting on the T/P s/c for the purpose of understanding and providing an explanation for the anomalous accelerations. The radiation forces acting on the T/P solar army, which experiences warping due to temperature gradients between the front and back surfaces, are analyzed and the resulting along-track accelerations are determined. Characteristics similar to those of the anomalous acceleration are seen. This analysis led to the development of a new radiation form model, which includes solar array warping and a solar array deployment deflection of as large as 2 deg. As a result of this new model estimates of the empirical along-track acceleration are reduced in magnitude when compared to the GSFC tuned macromodel and are less dependent upon beta(prime), the location of the Sun relative to the orbit plane. If these results we believed to reflect the actual orientation of the T/P solar array then motion of the solar array must influence the location of the s/c center of mass. Preliminary estimates indicate that the center of mass can vary by as much as 3 cm in the radial component of the s/c's position due to rotation of the deflected, warped solar array panel .The altimeter measurements rely upon accurate knowledge of the center of mass location relative to the s/c frame of reference. Any radial motion of the center of mass directly affects the altimeter measurements.

  18. Relative Humidity in Limited Streamer Tubes for Stanford Linear Accelerator Center's BaBar Detector

    SciTech Connect

    Lang, M.I.; Convery, M.; Menges, W.; /Queen Mary, U. of London

    2005-12-15

    The BABAR Detector at the Stanford Linear Accelerator Center studies the decay of B mesons created in e{sup +}e{sup -} collisions. The outermost layer of the detector, used to detect muons and neutral hadrons created during this process, is being upgraded from Resistive Plate Chambers (RPCs) to Limited Streamer Tubes (LSTs). The standard-size LST tube consists of eight cells, where a silver-plated wire runs down the center of each. A large potential difference is placed between the wires and ground. Gas flows through a series of modules connected with tubing, typically four. LSTs must be carefully tested before installation, as it will be extremely difficult to repair any damage once installed in the detector. In the testing process, the count rate in most modules showed was stable and consistent with cosmic ray rate over an approximately 500 V operating range between 5400 to 5900 V. The count in some modules, however, was shown to unexpectedly spike near the operation point. In general, the modules through which the gas first flows did not show this problem, but those further along the gas chain were much more likely to do so. The suggestion was that this spike was due to higher humidity in the modules furthest from the fresh, dry inflowing gas, and that the water molecules in more humid modules were adversely affecting the modules' performance. This project studied the effect of humidity in the modules, using a small capacitive humidity sensor (Honeywell). The sensor provided a humidity-dependent output voltage, as well as a temperature measurement from a thermistor. A full-size hygrometer (Panametrics) was used for testing and calibrating the Honeywell sensors. First the relative humidity of the air was measured. For the full calibration, a special gas-mixing setup was used, where relative humidity of the LST gas mixture could be varied from almost dry to almost fully saturated. With the sensor calibrated, a set of sensors was used to measure humidity vs. time

  19. Modeling the Gamma-Ray Emission in the GALACTIC CENTER with a Fading Cosmic-ray Accelerator

    NASA Astrophysics Data System (ADS)

    Liu, Ruo-Yu; Wang, Xiang-Yu; Prosekin, Anton; Chang, Xiao-Chuan

    2016-12-01

    Recent HESS observations of the ∼200 pc scale diffuse gamma-ray emission from the central molecular zone (CMZ) suggest the presence of a PeV cosmic-ray accelerator (PeVatron) located in the inner 10 pc region of the Galactic center. Interestingly, the gamma-ray spectrum of the point-like source (HESS J1745-290) in the Galactic center shows a cutoff at ∼10 TeV, implying a cutoff around 100 TeV in the cosmic-ray proton spectrum. Here we propose that the gamma-ray emission from the inner and the outer regions may be explained self-consistently by run-away protons from a single yet fading accelerator. In this model, gamma-rays from the CMZ region are produced by protons injected in the past, while gamma-rays from the inner region are produced by protons injected more recently. We suggest that the blast wave formed in a tidal disruption event (TDE) caused by the supermassive black hole (Sgr A*) could serve as such a fading accelerator. With typical parameters of the TDE blast wave, gamma-ray spectra of both the CMZ region and HESS J1745-290 can be reproduced simultaneously. Meanwhile, we find that the cosmic-ray energy density profile in the CMZ region may also be reproduced in the fading accelerator model when appropriate combinations of the particle injection history and the diffusion coefficient of cosmic rays are adopted.

  20. Comparing joint kinematics and center of mass acceleration as feedback for control of standing balance by functional neuromuscular stimulation

    PubMed Central

    2012-01-01

    Background The purpose of this study was to determine the comparative effectiveness of feedback control systems for maintaining standing balance based on joint kinematics or total body center of mass (COM) acceleration, and assess their clinical practicality for standing neuroprostheses after spinal cord injury (SCI). Methods In simulation, controller performance was measured according to the upper extremity effort required to stabilize a three-dimensional model of bipedal standing against a variety of postural disturbances. Three cases were investigated: proportional-derivative control based on joint kinematics alone, COM acceleration feedback alone, and combined joint kinematics and COM acceleration feedback. Additionally, pilot data was collected during external perturbations of an individual with SCI standing with functional neuromuscular stimulation (FNS), and the resulting joint kinematics and COM acceleration data was analyzed. Results Compared to the baseline case of maximal constant muscle excitations, the three control systems reduced the mean upper extremity loading by 51%, 43% and 56%, respectively against external force-pulse perturbations. Controller robustness was defined as the degradation in performance with increasing levels of input errors expected with clinical deployment of sensor-based feedback. At error levels typical for body-mounted inertial sensors, performance degradation due to sensor noise and placement were negligible. However, at typical tracking error levels, performance could degrade as much as 86% for joint kinematics feedback and 35% for COM acceleration feedback. Pilot data indicated that COM acceleration could be estimated with a few well-placed sensors and efficiently captures information related to movement synergies observed during perturbed bipedal standing following SCI. Conclusions Overall, COM acceleration feedback may be a more feasible solution for control of standing with FNS given its superior robustness and small

  1. Accelerate!

    PubMed

    Kotter, John P

    2012-11-01

    The old ways of setting and implementing strategy are failing us, writes the author of Leading Change, in part because we can no longer keep up with the pace of change. Organizational leaders are torn between trying to stay ahead of increasingly fierce competition and needing to deliver this year's results. Although traditional hierarchies and managerial processes--the components of a company's "operating system"--can meet the daily demands of running an enterprise, they are rarely equipped to identify important hazards quickly, formulate creative strategic initiatives nimbly, and implement them speedily. The solution Kotter offers is a second system--an agile, networklike structure--that operates in concert with the first to create a dual operating system. In such a system the hierarchy can hand off the pursuit of big strategic initiatives to the strategy network, freeing itself to focus on incremental changes to improve efficiency. The network is populated by employees from all levels of the organization, giving it organizational knowledge, relationships, credibility, and influence. It can Liberate information from silos with ease. It has a dynamic structure free of bureaucratic layers, permitting a level of individualism, creativity, and innovation beyond the reach of any hierarchy. The network's core is a guiding coalition that represents each level and department in the hierarchy, with a broad range of skills. Its drivers are members of a "volunteer army" who are energized by and committed to the coalition's vividly formulated, high-stakes vision and strategy. Kotter has helped eight organizations, public and private, build dual operating systems over the past three years. He predicts that such systems will lead to long-term success in the 21st century--for shareholders, customers, employees, and companies themselves.

  2. NINR Centers of Excellence: A logic model for sustainability, leveraging resources and collaboration to accelerate cross-disciplinary science

    PubMed Central

    Dorsey, Susan G.; Schiffman, Rachel; Redeker, Nancy S.; Heitkemper, Margaret; McCloskey, Donna Jo; Weglicki, Linda S.; Grady, Patricia A.

    2014-01-01

    The NINR Centers of Excellence program is a catalyst enabling institutions to develop infrastructure and administrative support for creating cross-disciplinary teams that bring multiple strategies and expertise to bear on common areas of science. Centers are increasingly collaborative with campus partners and reflect an integrated team approach to advance science and promote the development of scientists in these areas. The purpose of this paper is to present a NINR Logic Model for Center Sustainability. The components of the logic model were derived from the presentations and robust discussions at the 2013 NINR Center Directors’ meeting focused on best practices for leveraging resources and collaboration as methods to promote center sustainability. Collaboration through development and implementation of cross-disciplinary research teams is critical to accelerate the generation of new knowledge for solving fundamental health problems. Sustainability of centers as a long-term outcome beyond the initial funding can be enhanced by thoughtful planning of inputs, activities, and leveraging resources across multiple levels. PMID:25085328

  3. Restoration of accelerator facilities damaged by Great East Japan Earthquake at Cyclotron and Radioisotope Center, Tohoku University.

    PubMed

    Wakui, Takashi; Itoh, Masatoshi; Shimada, Kenzi; Yoshida, Hidetomo P; Shinozuka, Tsutomu; Sakemi, Yasuhiro

    2014-01-01

    The Cyclotron and Radioisotope Center (CYRIC) of Tohoku University is a joint-use institution for education and research in a wide variety of fields ranging from physics to medicine. Accelerator facilities at the CYRIC provide opportunities for implementing a broad research program, including medical research using positron emission tomography (PET), with accelerated ions and radioisotopes. At the Great East Japan Earthquake on March 11, 2011, no human injuries occurred and a smooth evacuation was made in the CYRIC, thanks to the anti-earthquake measures such as the renovation of the cyclotron building in 2009 mainly to provide seismic strengthening, fixation of shelves to prevent the falling of objects, and securement of the width of the evacuation route. The preparation of an emergency response manual was also helpful. However, the accelerator facilities were damaged because of strong shaking that continued for a few minutes. For example, two columns on which a 930 cyclotron was placed were damaged, and thereby the 930 cyclotron was inclined. All the elements of beam transport lines were deviated from the beam axis. Some peripheral devices in a HM12 cyclotron were broken. Two shielding doors fell from the carriage onto the floor and blocked the entrances to the rooms. The repair work on the accelerator facilities was started at the end of July 2011. During the repair work, the joint use of the accelerator facilities was suspended. After the repair work was completed, the joint use was re-started at October 2012, one and a half years after the earthquake.

  4. Non-actively controlled double-inverted-pendulum-like dynamics can minimize center of mass acceleration during human quiet standing.

    PubMed

    Suzuki, Yasuyuki; Morimoto, Hiroki; Kiyono, Ken; Morasso, Pietro; Nomura, Taishin

    2015-08-01

    Multiple joint movements during human quiet standing exhibit characteristic inter-joint coordination, shortly referred to as reciprocal relationship, in which angular acceleration of the hip joint is linearly and negatively correlated with that of the ankle joint (antiphase coordination) and, moreover, acceleration of the center of mass (CoM) of the double-inverted-pendulum (DIP) model of the human body is close to zero constantly. A question considered in this study is whether the reciprocal relationship is established by active neural control of the posture, or rather it is a biomechanical consequence of non-actively controlled body dynamics. To answer this question, we consider a DIP model of quiet standing, and show that the reciprocal relationship always holds by Newton's second law applied to the DIP model with human anthropometric dimensions, regardless of passive and active joint torque patterns acting on the ankle and hip joints. We then show that characteristic frequencies included in experimental sway trajectories with the reciprocal relationship match with harmonics of the eigenfrequency of the stable antiphase eigenmode of the non-actively controlled DIP-like unstable body dynamics. The results suggest that non-actively controlled DIP-like mechanical dynamics is a major cause of the minimization of the CoM acceleration during quiet standing, which is consistent with a type of control strategy that allows switching off active neural control intermittently for suitable periods of time during quiet standing.

  5. Joining Forces: How Student Success Centers Are Accelerating Statewide Community College Improvement Efforts

    ERIC Educational Resources Information Center

    Couturier, Lara K.

    2013-01-01

    There's an emerging trend in the national college completion movement. A group of small but powerful Student Success Centers is creating statewide impact in states traditionally devoid of a strong centralized tradition of community college governance. Growing directly out of a decade of hard work to dramatically boost student completion rates in…

  6. Evaluation of DoD Information Analysis Centers Program: Representative Sample Study - Benefits to DoD from Use of DoD Information Analysis Centers

    DTIC Science & Technology

    1990-06-01

    I A. History ........................................................................................ I B. IDA Tasking...8 / 1. REPORT BACKGROUND AND INTRODUCTION A. HISTORY The Department of Defense operates 22 Centers for the Analysis of Scientific and Technical...Department of Defettse (Alexandria, VA: Defense Logistics Agency, DTICITR.87/17, 1987), pp. 13-17, for a br’ef history of the DoD Information Analysis

  7. A projection-free method for representing plane-wave DFT results in an atom-centered basis

    SciTech Connect

    Dunnington, Benjamin D.; Schmidt, J. R.

    2015-09-14

    Plane wave density functional theory (DFT) is a powerful tool for gaining accurate, atomic level insight into bulk and surface structures. Yet, the delocalized nature of the plane wave basis set hinders the application of many powerful post-computation analysis approaches, many of which rely on localized atom-centered basis sets. Traditionally, this gap has been bridged via projection-based techniques from a plane wave to atom-centered basis. We instead propose an alternative projection-free approach utilizing direct calculation of matrix elements of the converged plane wave DFT Hamiltonian in an atom-centered basis. This projection-free approach yields a number of compelling advantages, including strict orthonormality of the resulting bands without artificial band mixing and access to the Hamiltonian matrix elements, while faithfully preserving the underlying DFT band structure. The resulting atomic orbital representation of the Kohn-Sham wavefunction and Hamiltonian provides a gateway to a wide variety of analysis approaches. We demonstrate the utility of the approach for a diverse set of chemical systems and example analysis approaches.

  8. Accelerating change: Fostering innovation in healthcare delivery at academic medical centers.

    PubMed

    Ostrovsky, Andrey; Barnett, Michael

    2014-03-01

    Academic medical centers (AMCs) have the potential to be leaders in the era of healthcare delivery reform, but most have yet to display a commitment to delivery innovation on par with their commitment to basic research. Several institutional factors impede delivery innovation including the paucity of adequate training in design and implementation of new delivery models and the lack of established pathways for academic career advancement outside of research. This paper proposes two initiatives to jumpstart disruptive innovation at AMCs: an institutional "innovation incubator" program and a clinician-innovator career track coupled with innovation training programs.

  9. The design of the electron beam dump unit of Turkish Accelerator Center (TAC)

    NASA Astrophysics Data System (ADS)

    Cite, L. H.; Yilmaz, M.

    2016-03-01

    The required simulations of the electron beam interactions for the design of electron beam dump unit for an accelerator which will operate to get two Infra-Red Free Electron Lasers (IR-FEL) covering the range of 3-250 microns is presented in this work. Simulations have been carried out to understand the interactions of a bulk of specially shaped of four different and widely used materials for the dump materials for a 77 pC, 40 MeV, 13 MHz repetition rate e-beam. In the simulation studies dump materials are chosen to absorb the 99% of the beam energy and to restrict the radio-isotope production in the bulk of the dump. A Lead shielding also designed around the dump core to prevent the leakage out of the all the emitted secondary radiations, e.g., neutrons, photons. The necessary dump material requirements, for the overall design considerations and the possible radiation originated effects on the dump unit, are discussed and presented.

  10. Routine Use of Continuous, Hyperfractionated, Accelerated Radiotherapy for Non-Small-Cell Lung Cancer: A Five-Center Experience

    SciTech Connect

    Din, Omar S. Lester, Jason; Cameron, Alison; Ironside, Janet; Gee, Amanda; Falk, Stephen; Morgan, Sally A.; Worvill, Jackie; Hatton, Matthew Q.F.

    2008-11-01

    Purpose: To report the results from continuous, hyperfractionated, accelerated radiotherapy (CHART) used as the standard fractionation for radical RT in the management of non-small cell lung cancer (NSCLC) in five United Kingdom centers. Methods and Materials: In 2005, the CHART consortium identified six U.K. centers that had continued to use CHART after the publication of the CHART study in 1997. All centers had been using CHART for >5 years and agreed to use a common database to audit their results. Patients treated with CHART between 1998 and December 2003 were identified to allow a minimum of 2 years of follow-up. Patient demographics, tumor characteristics, treatment details, and survival were recorded retrospectively. Five centers completed the data collection. Results: A total of 583 patients who had received CHART were identified. Of these patients, 69% were male, with a median age of 68 years (range, 31-89); 83% had performance status 0 or 1; and 43% had Stage I or II disease. Of the 583 patients, 99% received the prescribed dose. In only 4 patients was any Grade 4-5 toxicity documented. The median survival from the start of RT was 16.2 months, and the 2-year survival rate of 34% was comparable to that reported in the original study. Conclusion: The results of this unselected series have confirmed that CHART is deliverable in routine clinical practice, with low levels of toxicity. Importantly, this series has demonstrated that the results of CHART reported from the randomized trial can be reproduced in routine clinical practice.

  11. Natural and Accelerated Bioremediation Research (NABIR) Field Research Center (FRC), Oak Ridge Tennessee

    SciTech Connect

    Watson, David; Jardine, Philip; Gu, Baohua; Parker, Jack; Brandt, Craig; Holladay, Susan; Wolfe, Amy; Bogle, Mary Anna; Lowe, Kenneth; Hyder, Kirk

    2006-06-01

    The Field Research Center (FRC) in Oak Ridge (Fig. 1), Tennessee supports the U.S. Department of Energy's (DOE's) Environmental Remediation Sciences Program (ERSP) goal of understanding the complex physical, chemical, and biological properties of contaminated sites for new solutions to environmental remediation and long-term stewardship. In particular, the FRC provides the opportunity for researchers to conduct studies that promote the understanding of the processes that influence the transport and fate of subsurface contaminants, the effectiveness and long-term consequences of existing remediation options, and the development of improved remediation strategies. It offers a series of contaminated sites around the former S-3 Waste Disposal Ponds and uncontaminated sites in which investigators and students conduct field research or collect samples for laboratory analysis. FRC research also spurs the development of new and improved characterization and monitoring tools. Site specific knowledge gained from research conducted at the FRC also provides the DOE-Oak Ridge Office of Environmental Management (EM) the critical scientific knowledge needed to make cleanup decisions for the S-3 Ponds and other sites on the Oak Ridge Reservation (ORR).

  12. Final Environmental Assessment for the construction and operation of an office building at the Stanford Linear Accelerator Center. Part 2

    SciTech Connect

    1995-08-01

    The Department of Energy (DOE) has prepared an Environmental Assessment (EA), DOE/EA-1107, analyzing the environmental effects relating to the construction and operation of an office building at the Stanford Linear Accelerator Center (SLAC). SLAC is a national facility operated by Stanford University, California, under contract with DOE. The center is dedicated to research in elementary particle physics and in those fields that make use of its synchrotron facilities. The objective for the construction and operation of an office building is to provide adequate office space for existing SLAC Waste Management (WM) personnel, so as to centralize WM personnel and to make WM operations more efficient and effective. Based on the analyses in the EA, the DOE has determined that the proposed action does not constitute a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act of 1969 (NEPA). Therefore, the preparation of an Environmental Impact Statement is not required. This report contains the Environmental Assessment, as well as the Finding of No Significant Impact (FONSI).

  13. Measuring the wobble of radiation field centers during gantry rotation and collimator movement on a linear accelerator

    SciTech Connect

    Du, Weiliang; Gao, Song

    2011-08-15

    Purpose: The isocenter accuracy of a linear accelerator is often assessed with star-shot films. This approach is limited in its ability to quantify three dimensional wobble of radiation field centers (RFCs). The authors report a Winston-Lutz based method to measure the 3D wobble of RFCs during gantry rotation, collimator rotation, and collimator field size change. Methods: A stationary ball-bearing phantom was imaged using multileaf collimator-shaped radiation fields at various gantry angles, collimator angles, and field sizes. The center of the ball-bearing served as a reference point, to which all RFCs were localized using a computer algorithm with subpixel accuracy. Then, the gantry rotation isocenter and the collimator rotation axis were derived from the coordinates of these RFCs. Finally, the deviation or wobble of the individual RFC from the derived isocenter or rotation axis was quantified. Results: The results showed that the RFCs were stable as the field size of the multileaf collimator was varied. The wobble of RFCs depended on the gantry angle and the collimator angle and was reproducible, indicating that the mechanical imperfections of the linac were mostly systematic and quantifiable. It was found that the 3D wobble of RFCs during gantry rotation was reduced after compensating for a constant misalignment of the multileaf collimator. Conclusions: The 3D wobble of RFCs can be measured with submillimeter precision using the proposed method. This method provides a useful tool for checking and adjusting the radiation isocenter tightness of a linac.

  14. Difference in Postural Control during Quiet Standing between Young Children and Adults: Assessment with Center of Mass Acceleration.

    PubMed

    Oba, Naoko; Sasagawa, Shun; Yamamoto, Akio; Nakazawa, Kimitaka

    2015-01-01

    The development of upright postural control has often been investigated using time series of center of foot pressure (COP), which is proportional to the ankle joint torque (i.e., the motor output of a single joint). However, the center of body mass acceleration (COMacc), which can reflect joint motions throughout the body as well as multi-joint coordination, is useful for the assessment of the postural control strategy at the whole-body level. The purpose of the present study was to investigate children's postural control during quiet standing by using the COMacc. Ten healthy children and 15 healthy young adults were instructed to stand upright quietly on a force platform with their eyes open or closed. The COMacc as well as the COP in the anterior-posterior direction was obtained from ground reaction force measurement. We found that both the COMacc and COP could clearly distinguish the difference between age groups and visual conditions. We also found that the sway frequency of COMacc in children was higher than that in adults, for which differences in biomechanical and/or neural factors between age groups may be responsible. Our results imply that the COMacc can be an alternative force platform measure for assessing developmental changes in upright postural control.

  15. Metabolic control in a nationally representative diabetic elderly sample in Costa Rica: patients at community health centers vs. patients at other health care settings

    PubMed Central

    Brenes-Camacho, Gilbert; Rosero-Bixby, Luis

    2008-01-01

    Background Costa Rica, like other developing countries, is experiencing an increasing burden of chronic conditions such as diabetes mellitus (DM), especially among its elderly population. This article has two goals: (1) to assess the level of metabolic control among the diabetic population age ≥ 60 years old in Costa Rica, and (2) to test whether diabetic elderly patients of community health centers differ from patients in other health care settings in terms of the level of metabolic control. Methods Data come from the project CRELES, a nationally representative study of people aged 60 and over in Costa Rica. This article analyzes a subsample of 542 participants in CRELES with self-reported diagnosis of diabetes mellitus. Odds ratios of poor levels of metabolic control at different health care settings are computed using logistic regressions. Results Lack of metabolic control among elderly diabetic population in Costa Rica is described as follows: 37% have glycated hemoglobin ≥ 7%; 78% have systolic blood pressure ≥ 130 mmHg; 66% have diastolic blood pressure ≥ 80 mmHg; 48% have triglycerides ≥ 150 mg/dl; 78% have LDL ≥ 100 mg/dl; 70% have HDL ≤ 40 mg/dl. Elevated levels of triglycerides and LDL were higher in patients of community health centers than in patients of other clinical settings. There were no statistical differences in the other metabolic control indicators across health care settings. Conclusion Levels of metabolic control among elderly population with DM in Costa Rica are not that different from those observed in industrialized countries. Elevated levels of triglycerides and LDL at community health centers may indicate problems of dyslipidemia treatment among diabetic patients; these problems are not observed in other health care settings. The Costa Rican health care system should address this problem, given that community health centers constitute a means of democratizing access to primary health care to underserved and poor areas. PMID

  16. Minimum acceleration with constraints of center of mass: a unified model for arm movements and object manipulation.

    PubMed

    Leib, Raz; Karniel, Amir

    2012-09-01

    Daily interaction with the environment consists of moving with or without objects. Increasing interest in both types of movements drove the creation of computational models to describe reaching movements and, later, to describe a simplified version of object manipulation. The previously suggested models for object manipulation rely on the same optimization criteria as models for reaching movements, yet there is no single model accounting for both tasks that does not require reminimization of the criterion for each environment. We suggest a unified model for both cases: minimum acceleration with constraints for the center of mass (MACM). For point-to-point reaching movement, the model predicts the typical rectilinear path and bell-shaped speed profile as previous criteria. We have derived the predicted trajectories for the case of manipulating a mass-on-spring and show that the predicted trajectories match the observations of a few independent previous experimental studies of human arm movement during a mass-on-spring manipulation. Moreover, the previously reported "unusual" trajectories are also well accounted for by the proposed MACM. We have tested the predictions of the MACM model in 3 experiments with 12 subjects, where we demonstrated that the MACM model is equal or better (Wilcoxon sign-rank test, P < 0.001) in accounting for the data than three other previously proposed models in the conditions tested. Altogether, the MACM model is currently the only model accounting for reaching movements with or without external degrees of freedom. Moreover, it provides predictions about the intermittent nature of the neural control of movements and about the dominant control variable.

  17. SU-E-J-137: Image Registration Tool for Patient Setup in Korea Heavy Ion Medical Accelerator Center

    SciTech Connect

    Kim, M; Suh, T; Cho, W; Jung, W

    2015-06-15

    Purpose: A potential validation tool for compensating patient positioning error was developed using 2D/3D and 3D/3D image registration. Methods: For 2D/3D registration, digitally reconstructed radiography (DRR) and three-dimensional computed tomography (3D-CT) images were applied. The ray-casting algorithm is the most straightforward method for generating DRR. We adopted the traditional ray-casting method, which finds the intersections of a ray with all objects, voxels of the 3D-CT volume in the scene. The similarity between the extracted DRR and orthogonal image was measured by using a normalized mutual information method. Two orthogonal images were acquired from a Cyber-Knife system from the anterior-posterior (AP) and right lateral (RL) views. The 3D-CT and two orthogonal images of an anthropomorphic phantom and head and neck cancer patient were used in this study. For 3D/3D registration, planning CT and in-room CT image were applied. After registration, the translation and rotation factors were calculated to position a couch to be movable in six dimensions. Results: Registration accuracies and average errors of 2.12 mm ± 0.50 mm for transformations and 1.23° ± 0.40° for rotations were acquired by 2D/3D registration using an anthropomorphic Alderson-Rando phantom. In addition, registration accuracies and average errors of 0.90 mm ± 0.30 mm for transformations and 1.00° ± 0.2° for rotations were acquired using CT image sets. Conclusion: We demonstrated that this validation tool could compensate for patient positioning error. In addition, this research could be the fundamental step for compensating patient positioning error at the first Korea heavy-ion medical accelerator treatment center.

  18. Environmental Assessment for Selection and Operation of the Proposed Field Research Centers for the Natural and Accelerated Bioremediation Research (NABIR) Program

    SciTech Connect

    N /A

    2000-04-18

    The US Department of Energy (DOE) Office of Biological and Environmental Research (OBER), within the Office of Science (SC), proposes to add a Field Research Center (FRC) component to the existing Natural and Accelerated Bioremediation Research (NABIR) Program. The NABIR Program is a ten-year fundamental research program designed to increase the understanding of fundamental biogeochemical processes that would allow the use of bioremediation approaches for cleaning up DOE's contaminated legacy waste sites. An FRC would be integrated with the existing and future laboratory and field research and would provide a means of examining the fundamental biogeochemical processes that influence bioremediation under controlled small-scale field conditions. The NABIR Program would continue to perform fundamental research that might lead to promising bioremediation technologies that could be demonstrated by other means in the future. For over 50 years, DOE and its predecessor agencies have been responsible for the research, design, and production of nuclear weapons, as well as other energy-related research and development efforts. DOE's weapons production and research activities generated hazardous, mixed, and radioactive waste products. Past disposal practices have led to the contamination of soils, sediments, and groundwater with complex and exotic mixtures of compounds. This contamination and its associated costs and risks represents a major concern to DOE and the public. The high costs, long duration, and technical challenges associated with remediating the subsurface contamination at DOE sites present a significant need for fundamental research in the biological, chemical, and physical sciences that will contribute to new and cost-effective solutions. One possible low-cost approach for remediating the subsurface contamination of DOE sites is through the use of a technology known as bioremediation. Bioremediation has been defined as the use of microorganisms to biodegrade or

  19. Study of acceleration of center of mass during sit-to-stand and stand-to-sit in patients with stroke

    PubMed Central

    Na, Eunjin; Hwang, Hyesun; Woo, Youngkeun

    2016-01-01

    [Purpose] The purpose of this study was to compare the center of mass during sit-to-stand and stand-to-sit activities in the timed up and go test between healthy subjects and patients with stroke. [Subjects and Methods] Thirty healthy participants and thirty patients with stroke volunteered for this study. Acceleration of the center of mass was measured using a wireless tri-axial accelerometer during sit-to-stand and stand-to-sit activities in the timed up and go test. Accelerometer data were analyzed using BTS G-studio software. [Results] The phase duration was significantly longer and the anterior-posterior, mediolateral, and vertical acceleration ranges were significantly lower during sit-to-stand for patients with stroke than for healthy controls. Further, phase duration and the mediolateral acceleration range during stand-to-sit differed significantly between healthy controls and subjects with stroke. [Conclusions] During training for the sit-to-stand activity, the focus should be all three balance dimensions, but during training for the stand-to-sit activity, the focus should be on improving mediolateral balance and asymmetrical foot positioning should be recommended. PMID:27799669

  20. LINEAR ACCELERATOR

    DOEpatents

    Christofilos, N.C.; Polk, I.J.

    1959-02-17

    Improvements in linear particle accelerators are described. A drift tube system for a linear ion accelerator reduces gap capacity between adjacent drift tube ends. This is accomplished by reducing the ratio of the diameter of the drift tube to the diameter of the resonant cavity. Concentration of magnetic field intensity at the longitudinal midpoint of the external sunface of each drift tube is reduced by increasing the external drift tube diameter at the longitudinal center region.

  1. Production and isolation of homologs of flerovium and element 115 at the Lawrence Livermore National Laboratory Center for Accelerator Mass Spectrometry

    SciTech Connect

    Despotopulos, John D.; Kmak, Kelly N.; Gharibyan, Narek; Brown, Thomas A.; Grant, Patrick M.; Henderson, Roger A.; Moody, Kent J.; Tumey, Scott J.; Shaughnessy, Dawn A.; Sudowe, Ralf

    2015-10-01

    Here, new procedures have been developed to isolate no-carrier-added (NCA) radionuclides of the homologs and pseudo-homologs of flerovium (Hg, Sn) and element 115 (Sb), produced by 12–15 MeV proton irradiation of foil stacks with the tandem Van-de-Graaff accelerator at the Lawrence Livermore National Laboratory Center for Accelerator Mass Spectrometry (CAMS) facility. The separation of 113Sn from natIn foil was performed with anion-exchange chromatography from hydrochloric and nitric acid matrices. A cation-exchange chromatography method based on hydrochloric and mixed hydrochloric/hydroiodic acids was used to separate 124Sb from natSn foil. A procedure using Eichrom TEVA resin was developed to separate 197Hg from Au foil. These results demonstrate the suitability of using the CAMS facility to produce NCA radioisotopes for studies of transactinide homologs.

  2. Production and isolation of homologs of flerovium and element 115 at the Lawrence Livermore National Laboratory Center for Accelerator Mass Spectrometry

    DOE PAGES

    Despotopulos, John D.; Kmak, Kelly N.; Gharibyan, Narek; ...

    2015-10-01

    Here, new procedures have been developed to isolate no-carrier-added (NCA) radionuclides of the homologs and pseudo-homologs of flerovium (Hg, Sn) and element 115 (Sb), produced by 12–15 MeV proton irradiation of foil stacks with the tandem Van-de-Graaff accelerator at the Lawrence Livermore National Laboratory Center for Accelerator Mass Spectrometry (CAMS) facility. The separation of 113Sn from natIn foil was performed with anion-exchange chromatography from hydrochloric and nitric acid matrices. A cation-exchange chromatography method based on hydrochloric and mixed hydrochloric/hydroiodic acids was used to separate 124Sb from natSn foil. A procedure using Eichrom TEVA resin was developed to separate 197Hg frommore » Au foil. These results demonstrate the suitability of using the CAMS facility to produce NCA radioisotopes for studies of transactinide homologs.« less

  3. Oversight on NIOSH: Educational Resource Centers. Hearing before the Subcommittee on Education and Labor. House of Representatives, Ninety-Ninth Congress, First Session, June 18, 1985.

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. House Committee on Education and Labor.

    Educational Resource Centers (ERC), which are funded by the National Institute for Occupational Safety and Health, are considered in these hearings. Attention is directed to how four centers are fulfilling their mission, special programs at the centers, and possible future projects. ERCs, which are located at 15 regional public and private…

  4. Preliminary design report of a relativistic-Klystron two-beam-accelerator based power source for a 1 TeV center-of-mass next linear collider

    SciTech Connect

    Yu, S.; Goffeney, N.; Henestroza, E.

    1995-02-22

    A preliminary point design for an 11.4 GHz power source for a 1 TeV center-of-mass Next Linear Collider (NLC) based on the Relativistic-Klystron Two-Beam-Accelerator (RK-TBA) concept is presented. The present report is the result of a joint LBL-LLNL systems study. consisting of three major thrust areas: physics, engineering, and costing. The new RK-TBA point design, together with our findings in each of these areas, are reported.

  5. Accelerator Mass Spectrometric (AMS) Measurements of Plutonium Activity Concentrations and 240Pu/239Pu Atom Ratios In Soil Extracts Supplied by the Carlsbad Environmental Monitoring & Research Center

    SciTech Connect

    Hamilton, T F; Brown, T A; Marchetti, A A; Martinelli, R E; Kehl, S R

    2005-02-28

    Plutonium-239 ({sup 239}Pu) and plutonium-239+240 ({sup 239+240}Pu) activities concentrations and {sup 240}Pu/{sup 239}Pu atom ratios are reported for a series of chemically purified soil extracts received from the Carlsbad Environmental Monitoring & Research Center (CEMRC) in New Mexico. Samples were analyzed without further purification at the Lawrence Livermore National Laboratory (LLNL) using accelerator mass spectrometry (AMS). This report also includes a brief description of the AMS system and internal laboratory procedures used to ensure the quality and reliability of the measurement data.

  6. Solar Technology Acceleration Center (SolarTAC): Cooperative Research and Development Final Report, CRADA Number CRD-07-259

    SciTech Connect

    Kramer, W.

    2011-10-01

    This agreement allowed NREL to serve as an advisor on SolarTAC - a collaborative effort between Xcel Energy, NREL, and the University of Colorado at Boulder. The collaboration was formed to accelerate pre-commercial and early commercial solar energy technologies to the marketplace. Through this CRADA, NREL participated in the deployment of solar energy generation technologies and related solar equipment for research, testing, validation, and demonstration purposes.

  7. The NASA Short-term Prediction Research and Transition (SPoRT) Center: A Collaborative Model for Accelerating Research into Operations

    NASA Technical Reports Server (NTRS)

    Goodman, S. J.; Lapenta, W.; Jedlovec, G.; Dodge, J.; Bradshaw, T.

    2003-01-01

    The NASA Short-term Prediction Research and Transition (SPoRT) Center in Huntsville, Alabama was created to accelerate the infusion of NASA earth science observations, data assimilation and modeling research into NWS forecast operations and decision-making. The principal focus of experimental products is on the regional scale with an emphasis on forecast improvements on a time scale of 0-24 hours. The SPoRT Center research is aligned with the regional prediction objectives of the US Weather Research Program dealing with 0-1 day forecast issues ranging from convective initiation to 24-hr quantitative precipitation forecasting. The SPoRT Center, together with its other interagency partners, universities, and the NASA/NOAA Joint Center for Satellite Data Assimilation, provides a means and a process to effectively transition NASA Earth Science Enterprise observations and technology to National Weather Service operations and decision makers at both the global/national and regional scales. This paper describes the process for the transition of experimental products into forecast operations, current products undergoing assessment by forecasters, and plans for the future.

  8. Federally Supported Centers Provide Needed Services for Runaways and Homeless Youths. Report to the Chairman, Subcommittee on Human Resources, Committee on Education and Labor, House of Representatives.

    ERIC Educational Resources Information Center

    General Accounting Office, Washington, DC. Div. of Human Resources.

    The Runaway and Homeless Youth Act authorizes funds under the Juvenile Justice and Delinquency Prevention Act of 1974 for community-based centers that serve the shelter needs of runaway or homeless youths. To examine the effectiveness of the programs and the characteristics of program participants, the Government Accounting Office (GAO) visited 17…

  9. Health Care: School-Based Health Centers Can Expand Access for Children. Report to the Chairman, Committee on Government Operations, House of Representatives.

    ERIC Educational Resources Information Center

    General Accounting Office, Washington, DC. Health, Education, and Human Services Div.

    This report reviews the role of school-based health centers (SBHCs) in expanding children's access to health care, and examines financial and other obstacles SBHCs must overcome. The report is based on a literature review; interviews with officials; and case studies conducted at eight SBHCs in California, New Mexico, and New York. The study found…

  10. Representing Curriculum

    ERIC Educational Resources Information Center

    Gaztambide-Fernandez, Ruben

    2009-01-01

    Handbooks denote representative authority, which gives their content normative value and through which editors and authors can emphasize certain views and orientations within a field. The representative authority of a handbook is reinforced in various ways, both obvious and subtle. The "SAGE Handbook of Curriculum and Instruction" is no exception…

  11. Angular Acceleration without Torque?

    ERIC Educational Resources Information Center

    Kaufman, Richard D.

    2012-01-01

    Hardly. Just as Robert Johns qualitatively describes angular acceleration by an internal force in his article "Acceleration Without Force?" here we will extend the discussion to consider angular acceleration by an internal torque. As we will see, this internal torque is due to an internal force acting at a distance from an instantaneous center.

  12. Harnessing person-generated health data to accelerate patient-centered outcomes research: the Crohn's and Colitis Foundation of America PCORnet Patient Powered Research Network (CCFA Partners).

    PubMed

    Chung, Arlene E; Sandler, Robert S; Long, Millie D; Ahrens, Sean; Burris, Jessica L; Martin, Christopher F; Anton, Kristen; Robb, Amber; Caruso, Thomas P; Jaeger, Elizabeth L; Chen, Wenli; Clark, Marshall; Myers, Kelly; Dobes, Angela; Kappelman, Michael D

    2016-05-01

    The Crohn's and Colitis Foundation of America Partners Patient-Powered Research Network (PPRN) seeks to advance and accelerate comparative effectiveness and translational research in inflammatory bowel diseases (IBDs). Our IBD-focused PCORnet PPRN has been designed to overcome the major obstacles that have limited patient-centered outcomes research in IBD by providing the technical infrastructure, patient governance, and patient-driven functionality needed to: 1) identify, prioritize, and undertake a patient-centered research agenda through sharing person-generated health data; 2) develop and test patient and provider-focused tools that utilize individual patient data to improve health behaviors and inform health care decisions and, ultimately, outcomes; and 3) rapidly disseminate new knowledge to patients, enabling them to improve their health. The Crohn's and Colitis Foundation of America Partners PPRN has fostered the development of a community of citizen scientists in IBD; created a portal that will recruit, retain, and engage members and encourage partnerships with external scientists; and produced an efficient infrastructure for identifying, screening, and contacting network members for participation in research.

  13. Calculation of Transactinide Homolog Isotope Production Reactions Possible with the Center for Accelerator Mass Spectrometry (CAMS) at Lawrence Livermore National Laboratory

    SciTech Connect

    Moody, K J; Shaughnessy, D A; Gostic, J M

    2011-11-29

    The LLNL heavy element group has been investigating the chemical properties of the heaviest elements over the past several years. The properties of the transactinides (elements with Z > 103) are often unknown due to their low production rates and short half-lives, which require lengthy cyclotron irradiations in order to make enough atoms for statistically significant evaluations of their chemistry. In addition, automated chemical methods are often required to perform consistent and rapid chemical separations on the order of minutes for the duration of the experiment, which can last from weeks to months. Separation methods can include extraction chromatography, liquid-liquid extraction, or gas-phase chromatography. Before a lengthy transactinide experiment can be performed at an accelerator, a large amount of preparatory work must be done both to ensure the successful application of the chosen chemical system to the transactinide chemistry problem being addressed, and to evaluate the behavior of the lighter elemental homologs in the same chemical system. Since transactinide chemistry is literally performed on one single atom, its chemical properties cannot be determined from bulk chemical matrices, but instead must be inferred from the behavior of the lighter elements that occur in its chemical group and in those of its neighboring elements. By first studying the lighter group homologs in a particular chemical system, when the same system is applied to the transactinide element under investigation, its decay properties can be directly compared to those of the homologues, thereby allowing an inference of its own chemistry. The Center for Accelerator Mass Spectrometry (CAMS) at Lawrence Livermore National Laboratory (LLNL) includes a 1 MV Tandem accelerator, capable of accelerating light ions such as protons to energies of roughly 15 MeV. By using the CAMS beamline, tracers of transactinide homolog elements can be produced both for development of chemical systems and

  14. Using the PubMatrix literature-mining resource to accelerate student-centered learning in a veterinary problem-based learning curriculum.

    PubMed

    David, John; Irizarry, Kristopher J L

    2009-01-01

    Problem-based learning (PBL) creates an atmosphere in which veterinary students must take responsibility for their own education. Unlike a traditional curriculum where students receive discipline-specific information by attending formal lectures, PBL is designed to elicit self-directed, student-centered learning such that each student determines (1) what he/she does not know (learning issues), (2) what he/she needs to learn, (3) how he/she will learn it, and (4) what resources he/she will use. One of the biggest challenges facing students in a PBL curriculum is efficient time management while pursuing learning issues. Bioinformatics resources, such as the PubMatrix literature-mining tool, allow access to tremendous amounts of information almost instantaneously. To accelerate student-centered learning it is necessary to include resources that enhance the rate at which students can process biomedical information. Unlike using the PubMed interface directly, the PubMatrix tool enables users to automate queries, allowing up to 1,000 distinct PubMed queries to be executed per single PubMatrix submission. Users may submit multiple PubMatrix queries per session, resulting in the ability to execute tens of thousands of PubMed queries in a single day. The intuitively organized results, which remain accessible from PubMatrix user accounts, enable students to rapidly assimilate and process hundreds of thousands of individual publication records as they relate to the student's specific learning issues and query terms. Subsequently, students can explore substantially more of the biomedical publication landscape per learning issue and spend a greater fraction of their time actively engaged in resolving their learning issues.

  15. Representing dispositions

    PubMed Central

    2011-01-01

    Dispositions and tendencies feature significantly in the biomedical domain and therefore in representations of knowledge of that domain. They are not only important for specific applications like an infectious disease ontology, but also as part of a general strategy for modelling knowledge about molecular interactions. But the task of representing dispositions in some formal ontological systems is fraught with several problems, which are partly due to the fact that Description Logics can only deal well with binary relations. The paper will discuss some of the results of the philosophical debate about dispositions, in order to see whether the formal relations needed to represent dispositions can be broken down to binary relations. Finally, we will discuss problems arising from the possibility of the absence of realizations, of multi-track or multi-trigger dispositions and offer suggestions on how to deal with them. PMID:21995952

  16. Mantle Heterogeneities and Crustal Processes of the Cascade Arc Represented by Basalts of the Poison Lake Chain, Lassen Volcanic Center, California

    NASA Astrophysics Data System (ADS)

    Wenner, J. M.; Teasdale, R.; Hiebing, M. S.; Lenz, Q. A.; Kroeninger, K.

    2013-12-01

    Basalts in the Poison Lake chain (PLC) include eight chemically distinct groups of primitive calc-alkaline basalts (defined by major element geochemistry and mineralogy). Located east of the Lassen Volcanic Center, PLC primitive basalts span the range of basalt compositions exposed throughout the entire Cascade arc (e.g. Ba: 100-1000 ppm; (Sr/P)n: 1.3 - 3.8; La/Yb: 4-26). PLC groups have trace-element and isotope ratios that show little evidence of direct genetic relationships among groups or a common source. Major, trace element and isotope ratios show evidence of contributions from multiple mantle sources including MORB, fluid rich subduction component and subduction-related sediment. Some groups record compositional variations from multiple mantle sources with minimal crustal processing. Similarly, preliminary probe data for olivine-spinel pairs suggest that some PLC groups are derived from heterogeneous mantle sources. Geochemical evidence indicates that other groups have petrogenetic histories that include crustal processes such as fractional crystallization, mixing or crustal contamination. Isotope ratios, major and trace element compositions and crystal compositions provide insights into the extent of source heterogeneities versus the degree of crustal processing. The broad range of compositional variations in basalts of PLC provides the opportunity to examine the extent of mantle heterogeneities and crustal processing in a small geographic area (50km2) for rocks that are nearly the same age (100-110 ka). The diverse primitive compositions erupted in the constrained time and space of the Poison Lake chain and the lack of genetic relationship among groups make it the ideal place to investigate the small scale nature of mantle domains and the roles of subduction and modification processes in the generation of basaltic compositions in arcs such as the Cascades, Mexico, Japan.

  17. Laser acceleration

    NASA Astrophysics Data System (ADS)

    Tajima, T.; Nakajima, K.; Mourou, G.

    2017-02-01

    The fundamental idea of Laser Wakefield Acceleration (LWFA) is reviewed. An ultrafast intense laser pulse drives coherent wakefield with a relativistic amplitude robustly supported by the plasma. While the large amplitude of wakefields involves collective resonant oscillations of the eigenmode of the entire plasma electrons, the wake phase velocity ˜ c and ultrafastness of the laser pulse introduce the wake stability and rigidity. A large number of worldwide experiments show a rapid progress of this concept realization toward both the high-energy accelerator prospect and broad applications. The strong interest in this has been spurring and stimulating novel laser technologies, including the Chirped Pulse Amplification, the Thin Film Compression, the Coherent Amplification Network, and the Relativistic Mirror Compression. These in turn have created a conglomerate of novel science and technology with LWFA to form a new genre of high field science with many parameters of merit in this field increasing exponentially lately. This science has triggered a number of worldwide research centers and initiatives. Associated physics of ion acceleration, X-ray generation, and astrophysical processes of ultrahigh energy cosmic rays are reviewed. Applications such as X-ray free electron laser, cancer therapy, and radioisotope production etc. are considered. A new avenue of LWFA using nanomaterials is also emerging.

  18. Linear Accelerators

    NASA Astrophysics Data System (ADS)

    Sidorin, Anatoly

    2010-01-01

    In linear accelerators the particles are accelerated by either electrostatic fields or oscillating Radio Frequency (RF) fields. Accordingly the linear accelerators are divided in three large groups: electrostatic, induction and RF accelerators. Overview of the different types of accelerators is given. Stability of longitudinal and transverse motion in the RF linear accelerators is briefly discussed. The methods of beam focusing in linacs are described.

  19. Quality Assurance Plan for Field Activities at the Natural and Accelerated Bioremediation Research (NABIR) Field Research Center (FRC), Oak Ridge, Tennessee

    SciTech Connect

    Brandt, C.C.

    2002-02-28

    The Environmental Sciences Division (ESD) at Oak Ridge National Laboratory (ORNL) has established a Natural and Accelerated Bioremediation Research (NABIR) program Field Research Center (FRC) for the U.S. Department of Energy (DOE) Office of Biological and Environmental Research. The FRC is located in Bear Creek Valley within the Y-12 Plant area of responsibility on DOE's Oak Ridge Reservation in Tennessee. The NABIR program is a long-term effort designed to increase the understanding of fundamental biogeochemical processes that would allow the use of bioremediation approaches for cleaning up DOE's contaminated legacy waste sites. The FRC provides a site for investigators in the NABIR program to conduct research and obtain samples related to in situ bioremediation. The FRC is integrated with existing and future laboratory and field research and provides a means of examining the biogeochemical processes that influence bioremediation under controlled small-scale field conditions. This Quality Assurance Plan (QAP) documents the quality assurance protocols for field and laboratory activities performed by the FRC staff. It supplements the requirements in the ORNL Nuclear Quality Assurance Program and the ESD Quality Assurance Program. The QAP addresses the requirements in Title 10 CFR, Part 830 Subpart A, ''Quality Assurance Requirements'', using a graded approach appropriate for Research and Development projects based on guidance from ''Implementation Guide for Quality Assurance Programs for Basic and Applied Research'' (DOE-ER-STD-6001-92). It also supports the NABIR FRC Management Plan (Watson and Quarles 2000a) which outlines the overall procedures, roles and responsibilities for conducting research at the FRC. The QAP summarizes the organization, work activities, and qualify assurance and quality control protocols that will be used to generate scientifically defensible data at the FRC. The QAP pertains to field measurements and sample collection conducted by the

  20. Regional Instrumentation Centers.

    ERIC Educational Resources Information Center

    Cromie, William J.

    1980-01-01

    Focuses on the activities of regional instrumentation centers that utilize the state-of-the-art instruments and methodology in basic scientific research. The emphasis is on the centers involved in mass spectroscopy, magnetic resonance spectroscopy, lasers, and accelerators. (SA)

  1. Can Accelerators Accelerate Learning?

    NASA Astrophysics Data System (ADS)

    Santos, A. C. F.; Fonseca, P.; Coelho, L. F. S.

    2009-03-01

    The 'Young Talented' education program developed by the Brazilian State Funding Agency (FAPERJ) [1] makes it possible for high-schools students from public high schools to perform activities in scientific laboratories. In the Atomic and Molecular Physics Laboratory at Federal University of Rio de Janeiro (UFRJ), the students are confronted with modern research tools like the 1.7 MV ion accelerator. Being a user-friendly machine, the accelerator is easily manageable by the students, who can perform simple hands-on activities, stimulating interest in physics, and getting the students close to modern laboratory techniques.

  2. Liquid Methane Conditioning Capabilities Developed at the NASA Glenn Research Center's Small Multi- Purpose Research Facility (SMiRF) for Accelerated Lunar Surface Storage Thermal Testing

    NASA Technical Reports Server (NTRS)

    Bamberger, Helmut H.; Robinson, R. Craig; Jurns, John M.; Grasl, Steven J.

    2011-01-01

    Glenn Research Center s Creek Road Cryogenic Complex, Small Multi-Purpose Research Facility (SMiRF) recently completed validation / checkout testing of a new liquid methane delivery system and liquid methane (LCH4) conditioning system. Facility checkout validation was conducted in preparation for a series of passive thermal control technology tests planned at SMiRF in FY10 using a flight-like propellant tank at simulated thermal environments from 140 to 350K. These tests will validate models and provide high quality data to support consideration of LCH4/LO2 propellant combination option for a lunar or planetary ascent stage.An infrastructure has been put in place which will support testing of large amounts of liquid methane at SMiRF. Extensive modifications were made to the test facility s existing liquid hydrogen system for compatibility with liquid methane. Also, a new liquid methane fluid conditioning system will enable liquid methane to be quickly densified (sub-cooled below normal boiling point) and to be quickly reheated to saturation conditions between 92 and 140 K. Fluid temperatures can be quickly adjusted to compress the overall test duration. A detailed trade study was conducted to determine an appropriate technique to liquid conditioning with regard to the SMiRF facility s existing infrastructure. In addition, a completely new roadable dewar has been procured for transportation and temporary storage of liquid methane. A new spherical, flight-representative tank has also been fabricated for integration into the vacuum chamber at SMiRF. The addition of this system to SMiRF marks the first time a large-scale liquid methane propellant test capability has been realized at Glenn.This work supports the Cryogenic Fluid Management Project being conducted under the auspices of the Exploration Technology Development Program, providing focused cryogenic fluid management technology efforts to support NASA s future robotic or human exploration missions.

  3. PARTICLE ACCELERATOR

    DOEpatents

    Teng, L.C.

    1960-01-19

    ABS>A combination of two accelerators, a cyclotron and a ring-shaped accelerator which has a portion disposed tangentially to the cyclotron, is described. Means are provided to transfer particles from the cyclotron to the ring accelerator including a magnetic deflector within the cyclotron, a magnetic shield between the ring accelerator and the cyclotron, and a magnetic inflector within the ring accelerator.

  4. [Projects to accelerate the practical use of innovative medical devices to collaborate with TWIns, Center for Advanced Biomedical Sciences, Waseda University and School of Engineering, The University of Tokyo].

    PubMed

    Niimi, Shingo; Umezu, Mitsuo; Iseki, Hiroshi; Harada, Hiroshi Kasanuki Noboru; Mitsuishi, Mamoru; Kitamori, Takehiko; Tei, Yuichi; Nakaoka, Ryusuke; Haishima, Yuji

    2014-01-01

    Division of Medical Devices has been conducting the projects to accelerate the practical use of innovative medical devices to collaborate with TWIns, Center for Advanced Biomedical Sciences, Waseda University and School of Engineering, The University of Tokyo. The TWIns has been studying to aim at establishment of preclinical evaluation methods by "Engineering Based Medicine", and established Regulatory Science Institute for Medical Devices. School of Engineering, The University of Tokyo has been studying to aim at establishment of assessment methodology for innovative minimally invasive therapeutic devices, materials, and nanobio diagnostic devices. This report reviews the exchanges of personnel, the implement systems and the research progress of these projects.

  5. Accelerating the Understanding and Development of Hydrogen Storage Materials: A Review of the Five-Year Efforts of the Three DOE Hydrogen Storage Materials Centers of Excellence

    NASA Astrophysics Data System (ADS)

    Klebanoff, Leonard E.; Ott, Kevin C.; Simpson, Lin J.; O'Malley, Kathleen; Stetson, Ned T.

    2014-06-01

    A technical review of the progress achieved in hydrogen storage materials development through the U.S. Department of Energy's (DOE) Fuel Cell Technologies Office and the three Hydrogen Storage Materials Centers of Excellence (CoEs), which ran from 2005 to 2010 is presented. The three CoEs were created to develop reversible metal hydrides, chemical hydrogen storage materials, and high-specific-surface-area (SSA) hydrogen sorbents. For each CoE, the approach taken is specified, key outcomes and accomplishments identified, and recommendations for future work are suggested. The Metal Hydride Center of Excellence addresses work on destabilized hydrides, including the LiBH/Mg2NiH4 system, borohydrides, amides, and alanes; and compares the best materials to DOE targets. The Chemical Hydrogen Storage Center of Excellence discusses the classes of materials studied for chemical hydrogen storage, focusing on ammonia borane and examines the progress in developing efficient regeneration schemes. The Hydrogen Sorption Center of Excellence describes the progress in developing high-SSA sorbents and pathways for developing improved materials capable of achieving DOE targets. The phenomenon of spillover is also observed and its importance to ensuring improved measurements is discussed. Through the five-year effort of the Hydrogen Storage Materials Centers of Excellence, significant progress was achieved in developing and understanding hydrogen storage materials.

  6. Future accelerators (?)

    SciTech Connect

    John Womersley

    2003-08-21

    I describe the future accelerator facilities that are currently foreseen for electroweak scale physics, neutrino physics, and nuclear structure. I will explore the physics justification for these machines, and suggest how the case for future accelerators can be made.

  7. FPGA Verification Accelerator (FVAX)

    NASA Technical Reports Server (NTRS)

    Oh, Jane; Burke, Gary

    2008-01-01

    Is Verification Acceleration Possible? - Increasing the visibility of the internal nodes of the FPGA results in much faster debug time - Forcing internal signals directly allows a problem condition to be setup very quickly center dot Is this all? - No, this is part of a comprehensive effort to improve the JPL FPGA design and V&V process.

  8. A positive family history of hypertension might be associated with an accelerated onset of type 2 diabetes: Results from the National Center Diabetes Database (NCDD-02).

    PubMed

    Yamamoto-Honda, Ritsuko; Takahashi, Yoshihiko; Mori, Yasumichi; Yamashita, Shigeo; Yoshida, Yoko; Kawazu, Shoji; Iwamoto, Yasuhiko; Kajio, Hiroshi; Yanai, Hidekatsu; Mishima, Shuichi; Handa, Nobuhiro; Shimokawa, Kotaro; Yoshida, Akiko; Watanabe, Hiroki; Ohe, Kazuhiko; Shimbo, Takuro; Noda, Mitsuhiko

    2017-03-18

    Type 2 diabetes, which is characterized by a combination of decreased insulin secretion and decreased insulin sensitivity, can be delayed or prevented by healthy lifestyle behaviors. Therefore, it is important that the population in general understands their personal risk at an early age to reduce their chances of ever developing the disease. A family history of hypertension is known to be associated with insulin resistance, but the effect of a family history of hypertension on the onset of type 2 diabetes has not well been examined. We performed a retrospective study examining patient age at the time of the diagnosis of type 2 diabetes by analyzing a dataset of 1,299 patients (1,021 men and 278 women) who had been diagnosed as having type 2 diabetes during a health checkup. The mean ± standard deviation of the patient age at the time of the diagnosis of diabetes was 49.1 ± 10.4 years for patients with a family history of hypertension and 51.8 ± 11.4 years for patients without a family history of hypertension (p < 0.001). A multivariate linear regression analysis showed a significant association between a family history of hypertension and a younger age at the time of the diagnosis of type 2 diabetes, independent of a family history of diabetes mellitus and a male sex, suggesting that a positive family history of hypertension might be associated with the accelerated onset of type 2 diabetes.

  9. Dedicated Linear Accelerator Radiosurgery for Trigeminal Neuralgia: A Single-Center Experience in 179 Patients With Varied Dose Prescriptions and Treatment Plans

    SciTech Connect

    Smith, Zachary A.; Gorgulho, Alessandra A.; Bezrukiy, Nikita; McArthur, David; Agazaryan, Nzhde; Selch, Michael T.; De Salles, Antonio A.F.

    2011-09-01

    Purpose: Dedicated linear accelerator radiosurgery (D-LINAC) has become an important treatment for trigeminal neuralgia (TN). Although the use of gamma knife continues to be established, few large series exist using D-LINAC. The authors describe their results, comparing the effects of varied target and dose regimens. Methods and Materials: Between August 1995 and January 2008, 179 patients were treated with D-LINAC radiosurgery. Ten patients (5.58%) had no clinical follow-up. The median age was 74.0 years (range, 32-90 years). A total of 39 patients had secondary or atypical pain, and 130 had idiopathic TN. Initially, 28 patients received doses between 70 and 85 Gy, with the 30% isodose line (IDL) touching the brainstem. Then, using 90 Gy, 82 consecutive patients were treated with a 30% IDL and 59 patients with a 50% IDL tangential to the pons. Results: Of 169 patients, 134 (79.3%) experienced significant relief at a mean of 28.8 months (range, 5-142 months). Average time to relief was 1.92 months (range, immediate to 6 months). A total of 31 patients (19.0%) had recurrent pain at 13.5 months. Of 87 patients with idiopathic TN without prior procedures, 79 (90.8%) had initial relief. Among 28 patients treated with 70 Gy and 30% IDL, 18 patients (64.3%) had significant relief, and 10 (35.7%) had numbness. Of the patients with 90 Gy and 30% IDL at the brainstem, 59 (79.0%) had significant relief and 48.9% had numbness. Among 59 consecutive patients with similar dose but the 50% isodoseline at the brainstem, 49 patients (88.0%) had excellent/good relief. Numbness, averaging 2.49 on a subjective scale of 1 to 5, was experienced by 49.7% of the patients, Conclusions: Increased radiation dose and volume of brainstem irradiation may improve clinical outcomes with the trade-off of trigeminal dysfunction. Further study of the implications of dose and target are needed to optimize outcomes and to minimize complications.

  10. Biomedical accelerator mass spectrometry

    NASA Astrophysics Data System (ADS)

    Freeman, Stewart P. H. T.; Vogel, John S.

    1995-05-01

    Ultrasensitive SIMS with accelerator based spectrometers has recently begun to be applied to biomedical problems. Certain very long-lived radioisotopes of very low natural abundances can be used to trace metabolism at environmental dose levels ( [greater-or-equal, slanted] z mol in mg samples). 14C in particular can be employed to label a myriad of compounds. Competing technologies typically require super environmental doses that can perturb the system under investigation, followed by uncertain extrapolation to the low dose regime. 41Ca and 26Al are also used as elemental tracers. Given the sensitivity of the accelerator method, care must be taken to avoid contamination of the mass spectrometer and the apparatus employed in prior sample handling including chemical separation. This infant field comprises the efforts of a dozen accelerator laboratories. The Center for Accelerator Mass Spectrometry has been particularly active. In addition to collaborating with groups further afield, we are researching the kinematics and binding of genotoxins in-house, and we support innovative uses of our capability in the disciplines of chemistry, pharmacology, nutrition and physiology within the University of California. The field can be expected to grow further given the numerous potential applications and the efforts of several groups and companies to integrate more the accelerator technology into biomedical research programs; the development of miniaturized accelerator systems and ion sources capable of interfacing to conventional HPLC and GMC, etc. apparatus for complementary chemical analysis is anticipated for biomedical laboratories.

  11. LINEAR ACCELERATOR

    DOEpatents

    Colgate, S.A.

    1958-05-27

    An improvement is presented in linear accelerators for charged particles with respect to the stable focusing of the particle beam. The improvement consists of providing a radial electric field transverse to the accelerating electric fields and angularly introducing the beam of particles in the field. The results of the foregoing is to achieve a beam which spirals about the axis of the acceleration path. The combination of the electric fields and angular motion of the particles cooperate to provide a stable and focused particle beam.

  12. Acceleration switch

    DOEpatents

    Abbin, Jr., Joseph P.; Devaney, Howard F.; Hake, Lewis W.

    1982-08-17

    The disclosure relates to an improved integrating acceleration switch of the type having a mass suspended within a fluid filled chamber, with the motion of the mass initially opposed by a spring and subsequently not so opposed.

  13. Acceleration switch

    DOEpatents

    Abbin, J.P. Jr.; Devaney, H.F.; Hake, L.W.

    1979-08-29

    The disclosure relates to an improved integrating acceleration switch of the type having a mass suspended within a fluid filled chamber, with the motion of the mass initially opposed by a spring and subsequently not so opposed.

  14. ION ACCELERATOR

    DOEpatents

    Bell, J.S.

    1959-09-15

    An arrangement for the drift tubes in a linear accelerator is described whereby each drift tube acts to shield the particles from the influence of the accelerating field and focuses the particles passing through the tube. In one embodiment the drift tube is splii longitudinally into quadrants supported along the axis of the accelerator by webs from a yoke, the quadrants. webs, and yoke being of magnetic material. A magnetic focusing action is produced by energizing a winding on each web to set up a magnetic field between adjacent quadrants. In the other embodiment the quadrants are electrically insulated from each other and have opposite polarity voltages on adjacent quadrants to provide an electric focusing fleld for the particles, with the quadrants spaced sufficienily close enough to shield the particles within the tube from the accelerating electric field.

  15. Seclusions and Restraints: Selected Cases of Death and Abuse at Public and Private Schools and Treatment Centers. Testimony Before the Committee on Education and Labor, House of Representatives. GAO-09-719T

    ERIC Educational Resources Information Center

    Kutz, Gregory D.

    2009-01-01

    The Government Accountability Office (GAO) recently testified before the Committee on Education and Labor, House of Representatives, regarding allegations of death and abuse at residential programs for troubled teens. The document presents the statement of Gregory D. Kutz, Managing Director, Forensic Audits and Special Investigations. Recent…

  16. idaho Accelerator Center Advanced Fuel Cycle Research

    SciTech Connect

    Wells, Douglas; Dale, Dan

    2011-10-20

    The technical effort has been in two parts called; Materials Science and Instrumentation Development. The Materials Science technical program has been based on a series of research and development achievements in Positron-Annihilation Spectroscopy (PAS) for defect detection in structural materials. This work is of particular importance in nuclear power and its supporting systems as the work included detection of defects introduced by mechanical and thermal phenomena as well as those caused by irradiation damage. The second part of the program has focused on instrumentation development using active interrogation techniques supporting proliferation resistant recycling methodologies and nuclear material safeguards. This effort has also lead to basic physics studies of various phenomena relating to photo-fission. Highlights of accomplishments and facility improvement legacies in these areas over the program period include

  17. Acceleration Studies

    NASA Technical Reports Server (NTRS)

    Rogers, Melissa J. B.

    1993-01-01

    Work to support the NASA MSFC Acceleration Characterization and Analysis Project (ACAP) was performed. Four tasks (analysis development, analysis research, analysis documentation, and acceleration analysis) were addressed by parallel projects. Work concentrated on preparation for and implementation of near real-time SAMS data analysis during the USMP-1 mission. User support documents and case specific software documentation and tutorials were developed. Information and results were presented to microgravity users. ACAP computer facilities need to be fully implemented and networked, data resources must be cataloged and accessible, future microgravity missions must be coordinated, and continued Orbiter characterization is necessary.

  18. Dielectric laser accelerators

    NASA Astrophysics Data System (ADS)

    England, R. Joel; Noble, Robert J.; Bane, Karl; Dowell, David H.; Ng, Cho-Kuen; Spencer, James E.; Tantawi, Sami; Wu, Ziran; Byer, Robert L.; Peralta, Edgar; Soong, Ken; Chang, Chia-Ming; Montazeri, Behnam; Wolf, Stephen J.; Cowan, Benjamin; Dawson, Jay; Gai, Wei; Hommelhoff, Peter; Huang, Yen-Chieh; Jing, Chunguang; McGuinness, Christopher; Palmer, Robert B.; Naranjo, Brian; Rosenzweig, James; Travish, Gil; Mizrahi, Amit; Schachter, Levi; Sears, Christopher; Werner, Gregory R.; Yoder, Rodney B.

    2014-10-01

    The use of infrared lasers to power optical-scale lithographically fabricated particle accelerators is a developing area of research that has garnered increasing interest in recent years. The physics and technology of this approach is reviewed, which is referred to as dielectric laser acceleration (DLA). In the DLA scheme operating at typical laser pulse lengths of 0.1 to 1 ps, the laser damage fluences for robust dielectric materials correspond to peak surface electric fields in the GV /m regime. The corresponding accelerating field enhancement represents a potential reduction in active length of the accelerator between 1 and 2 orders of magnitude. Power sources for DLA-based accelerators (lasers) are less costly than microwave sources (klystrons) for equivalent average power levels due to wider availability and private sector investment. Because of the high laser-to-particle coupling efficiency, required pulse energies are consistent with tabletop microJoule class lasers. Combined with the very high (MHz) repetition rates these lasers can provide, the DLA approach appears promising for a variety of applications, including future high-energy physics colliders, compact light sources, and portable medical scanners and radiative therapy machines.

  19. Particle acceleration

    NASA Technical Reports Server (NTRS)

    Vlahos, L.; Machado, M. E.; Ramaty, R.; Murphy, R. J.; Alissandrakis, C.; Bai, T.; Batchelor, D.; Benz, A. O.; Chupp, E.; Ellison, D.

    1986-01-01

    Data is compiled from Solar Maximum Mission and Hinothori satellites, particle detectors in several satellites, ground based instruments, and balloon flights in order to answer fundamental questions relating to: (1) the requirements for the coronal magnetic field structure in the vicinity of the energization source; (2) the height (above the photosphere) of the energization source; (3) the time of energization; (4) transistion between coronal heating and flares; (5) evidence for purely thermal, purely nonthermal and hybrid type flares; (6) the time characteristics of the energization source; (7) whether every flare accelerates protons; (8) the location of the interaction site of the ions and relativistic electrons; (9) the energy spectra for ions and relativistic electrons; (10) the relationship between particles at the Sun and interplanetary space; (11) evidence for more than one acceleration mechanism; (12) whether there is single mechanism that will accelerate particles to all energies and also heat the plasma; and (13) how fast the existing mechanisms accelerate electrons up to several MeV and ions to 1 GeV.

  20. Plasma accelerator

    DOEpatents

    Wang, Zhehui; Barnes, Cris W.

    2002-01-01

    There has been invented an apparatus for acceleration of a plasma having coaxially positioned, constant diameter, cylindrical electrodes which are modified to converge (for a positive polarity inner electrode and a negatively charged outer electrode) at the plasma output end of the annulus between the electrodes to achieve improved particle flux per unit of power.

  1. Accelerated Achievement

    ERIC Educational Resources Information Center

    Ford, William J.

    2010-01-01

    This article focuses on the accelerated associate degree program at Ivy Tech Community College (Indiana) in which low-income students will receive an associate degree in one year. The three-year pilot program is funded by a $2.3 million grant from the Lumina Foundation for Education in Indianapolis and a $270,000 grant from the Indiana Commission…

  2. ACCELERATION INTEGRATOR

    DOEpatents

    Pope, K.E.

    1958-01-01

    This patent relates to an improved acceleration integrator and more particularly to apparatus of this nature which is gyrostabilized. The device may be used to sense the attainment by an airborne vehicle of a predetermined velocitv or distance along a given vector path. In its broad aspects, the acceleration integrator utilizes a magnetized element rotatable driven by a synchronous motor and having a cylin drical flux gap and a restrained eddy- current drag cap deposed to move into the gap. The angular velocity imparted to the rotatable cap shaft is transmitted in a positive manner to the magnetized element through a servo feedback loop. The resultant angular velocity of tae cap is proportional to the acceleration of the housing in this manner and means may be used to measure the velocity and operate switches at a pre-set magnitude. To make the above-described dcvice sensitive to acceleration in only one direction the magnetized element forms the spinning inertia element of a free gyroscope, and the outer housing functions as a gimbal of a gyroscope.

  3. Particle Accelerators in China

    NASA Astrophysics Data System (ADS)

    Zhang, Chuang; Fang, Shouxian

    As the special machines that can accelerate charged particle beams to high energy by using electromagnetic fields, particle accelerators have been widely applied in scientific research and various areas of society. The development of particle accelerators in China started in the early 1950s. After a brief review of the history of accelerators, this article describes in the following sections: particle colliders, heavy-ion accelerators, high-intensity proton accelerators, accelerator-based light sources, pulsed power accelerators, small scale accelerators, accelerators for applications, accelerator technology development and advanced accelerator concepts. The prospects of particle accelerators in China are also presented.

  4. Compact accelerator

    DOEpatents

    Caporaso, George J.; Sampayan, Stephen E.; Kirbie, Hugh C.

    2007-02-06

    A compact linear accelerator having at least one strip-shaped Blumlein module which guides a propagating wavefront between first and second ends and controls the output pulse at the second end. Each Blumlein module has first, second, and third planar conductor strips, with a first dielectric strip between the first and second conductor strips, and a second dielectric strip between the second and third conductor strips. Additionally, the compact linear accelerator includes a high voltage power supply connected to charge the second conductor strip to a high potential, and a switch for switching the high potential in the second conductor strip to at least one of the first and third conductor strips so as to initiate a propagating reverse polarity wavefront(s) in the corresponding dielectric strip(s).

  5. BICEP's acceleration

    SciTech Connect

    Contaldi, Carlo R.

    2014-10-01

    The recent Bicep2 [1] detection of, what is claimed to be primordial B-modes, opens up the possibility of constraining not only the energy scale of inflation but also the detailed acceleration history that occurred during inflation. In turn this can be used to determine the shape of the inflaton potential V(φ) for the first time — if a single, scalar inflaton is assumed to be driving the acceleration. We carry out a Monte Carlo exploration of inflationary trajectories given the current data. Using this method we obtain a posterior distribution of possible acceleration profiles ε(N) as a function of e-fold N and derived posterior distributions of the primordial power spectrum P(k) and potential V(φ). We find that the Bicep2 result, in combination with Planck measurements of total intensity Cosmic Microwave Background (CMB) anisotropies, induces a significant feature in the scalar primordial spectrum at scales k∼ 10{sup -3} Mpc {sup -1}. This is in agreement with a previous detection of a suppression in the scalar power [2].

  6. Acceleration display system for aircraft zero-gravity research

    NASA Technical Reports Server (NTRS)

    Millis, Marc G.

    1987-01-01

    The features, design, calibration, and testing of Lewis Research Center's acceleration display system for aircraft zero-gravity research are described. Specific circuit schematics and system specifications are included as well as representative data traces from flown trajectories. Other observations learned from developing and using this system are mentioned where appropriate. The system, now a permanent part of the Lewis Learjet zero-gravity program, provides legible, concise, and necessary guidance information enabling pilots to routinely fly accurate zero-gravity trajectories. Regular use of this system resulted in improvements of the Learjet zero-gravity flight techniques, including a technique to minimize later accelerations. Lewis Gates Learjet trajectory data show that accelerations can be reliably sustained within 0.01 g for 5 consecutive seconds, within 0.02 g for 7 consecutive seconds, and within 0.04 g for up to 20 second. Lewis followed the past practices of acceleration measurement, yet focussed on the acceleration displays. Refinements based on flight experience included evolving the ranges, resolutions, and frequency responses to fit the pilot and the Learjet responses.

  7. A diode for accelerating hydrogen nuclides with electron conductivity suppressed by an internal ring magnet

    NASA Astrophysics Data System (ADS)

    Shikanov, A. E.; Vovchenko, E. D.; Kozlovskii, K. I.; Shatokhin, V. L.

    2015-05-01

    We present new experimental data on the acceleration of deuterons in a small-size magnetically insulated diode. Plasma containing deuterons was created at the anode during irradiation of a TiD target by a focused laser beam with a wavelength of 1.06 μm. The accelerating voltage pulse was formed by an Arkadiev-Marx generator. A circular cathode was arranged symmetrically relative to the anode and represented a permanent ring magnet with an inner radius not exceeding 0.02 m and a magnetic induction of up to 0.4 T at the center, which ensured magnetic insulation of the accelerating gap. The experiments showed that the current of accelerated deuterons with energies of up to 300 eV can reach a level of 0.5 kA at pulse durations of ≤0.5 μs.

  8. Summary Report of Mission Acceleration Measurements for STS-65, Launched 8 July 1994

    NASA Technical Reports Server (NTRS)

    Rogers, Melissa J. B.; Delombard, Richard

    1995-01-01

    The second flight of the International Microgravity Laboratory (IML-2) payload on board the STS-65 mission was supported by three accelerometer instruments: The Orbital Acceleration Research Experiment (OARE) located close to the orbiter center of mass; the Quasi-Steady Acceleration Measurement experiment, and the Space Acceleration Measurement System (SAMS), both in the Spacelab module. A fourth accelerometer, the Microgravity Measuring Device recorded data in the middeck in support of exercise isolation tests.Data collected by OARE and SAMS during IML-2 are displayed in this report. The OARE data represent the microgravity environment below 1 Hz. The SAMS data represent the environment in the 0.01 Hz to 100 Hz range. Variations in the environment caused by unique activities are presented. Specific events addressed are: crew activity, crew exercise, experiment component mixing activities, experiment centrifuge operations, refrigerator/freezer operations and circulation pump operations. The analyses included in this report complement analyses presented in other mission summary reports.

  9. Representing Substantive Structures.

    ERIC Educational Resources Information Center

    Finley, Fred N.; Stewart, James

    1982-01-01

    Discusses the meaning of Schwab's "substantive structures" of a discipline in terms of science philosophy. Presents three techniques for representing substantive structures and discusses some of their uses in science education research. (SK)

  10. Accelerating Commercial Remote Sensing

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Through the Visiting Investigator Program (VIP) at Stennis Space Center, Community Coffee was able to use satellites to forecast coffee crops in Guatemala. Using satellite imagery, the company can produce detailed maps that separate coffee cropland from wild vegetation and show information on the health of specific crops. The data can control coffee prices and eventually may be used to optimize application of fertilizers, pesticides and irrigation. This would result in maximal crop yields, minimal pollution and lower production costs. VIP is a mechanism involving NASA funding designed to accelerate the growth of commercial remote sensing by promoting general awareness and basic training in the technology.

  11. Accelerated Innovation Pilot

    NASA Technical Reports Server (NTRS)

    Davis, Jeffrey

    2012-01-01

    Opportunities: I. Engage NASA team (examples) a) Research and technology calls . provide suggestions to AES, HRP, OCT. b) Use NASA@Work to solicit other ideas; (possibly before R+D calls). II. Stimulate collaboration (examples) a) NHHPC. b) Wharton Mack Center for Technological Innovation (Feb 2013). c) International ] DLR ] :envihab (July 2013). d) Accelerated research models . NSF, Myelin Repair Foundation. III. Engage public Prizes (open platform: InnoCentive, yet2.com, NTL; Rice Business Plan, etc.) IV. Use same methods to engage STEM.

  12. Advanced concepts for acceleration

    SciTech Connect

    Keefe, D.

    1986-07-01

    Selected examples of advanced accelerator concepts are reviewed. Such plasma accelerators as plasma beat wave accelerator, plasma wake field accelerator, and plasma grating accelerator are discussed particularly as examples of concepts for accelerating relativistic electrons or positrons. Also covered are the pulsed electron-beam, pulsed laser accelerator, inverse Cherenkov accelerator, inverse free-electron laser, switched radial-line accelerators, and two-beam accelerator. Advanced concepts for ion acceleration discussed include the electron ring accelerator, excitation of waves on intense electron beams, and two-wave combinations. (LEW)

  13. Accelerators and the Accelerator Community

    SciTech Connect

    Malamud, Ernest; Sessler, Andrew

    2008-06-01

    In this paper, standing back--looking from afar--and adopting a historical perspective, the field of accelerator science is examined. How it grew, what are the forces that made it what it is, where it is now, and what it is likely to be in the future are the subjects explored. Clearly, a great deal of personal opinion is invoked in this process.

  14. NASA Space Day in Mississippi - House of Representatives

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Astronaut Michael Foale (center) and Stennis Space Center officials met with Mississippi House of Representatives Gulf Coast delegation, including Speaker William 'Billy' McCoy (far right), during NASA Space Day in Mississippi on January 30.

  15. Impact accelerations

    NASA Technical Reports Server (NTRS)

    Vongierke, H. E.; Brinkley, J. W.

    1975-01-01

    The degree to which impact acceleration is an important factor in space flight environments depends primarily upon the technology of capsule landing deceleration and the weight permissible for the associated hardware: parachutes or deceleration rockets, inflatable air bags, or other impact attenuation systems. The problem most specific to space medicine is the potential change of impact tolerance due to reduced bone mass and muscle strength caused by prolonged weightlessness and physical inactivity. Impact hazards, tolerance limits, and human impact tolerance related to space missions are described.

  16. Representing properties locally.

    PubMed

    Solomon, K O; Barsalou, L W

    2001-09-01

    Theories of knowledge such as feature lists, semantic networks, and localist neural nets typically use a single global symbol to represent a property that occurs in multiple concepts. Thus, a global symbol represents mane across HORSE, PONY, and LION. Alternatively, perceptual theories of knowledge, as well as distributed representational systems, assume that properties take different local forms in different concepts. Thus, different local forms of mane exist for HORSE, PONY, and LION, each capturing the specific form that mane takes in its respective concept. Three experiments used the property verification task to assess whether properties are represented globally or locally (e.g., Does a PONY have mane?). If a single global form represents a property, then verifying it in any concept should increase its accessibility and speed its verification later in any other concept. Verifying mane for PONY should benefit as much from having verified mane for LION earlier as from verifying mane for HORSE. If properties are represented locally, however, verifying a property should only benefit from verifying a similar form earlier. Verifying mane for PONY should only benefit from verifying mane for HORSE, not from verifying mane for LION. Findings from three experiments strongly supported local property representation and ruled out the interpretation that object similarity was responsible (e.g., the greater overall similarity between HORSE and PONY than between LION and PONY). The findings further suggest that property representation and verification are complicated phenomena, grounded in sensory-motor simulations.

  17. The Orbital Acceleration Research Experiment

    NASA Technical Reports Server (NTRS)

    Blanchard, R. C.; Hendrix, M. K.; Fox, J. C.; Thomas, D. J.; Nicholson, J.

    1986-01-01

    The hardware and software of NASA's proposed Orbital Acceleration Research Experiment (OARE) are described. The OARE is to provide aerodynamic acceleration measurements along the Orbiter's principal axis in the free-molecular flow-flight regime at orbital attitude and in the transition regime during reentry. Models considering the effects of electromagnetic effects, solar radiation pressure, orbiter mass attraction, gravity gradient, orbital centripetal acceleration, out-of-orbital-plane effects, orbiter angular velocity, structural noise, mass expulsion signal sources, crew motion, and bias on acceleration are examined. The experiment contains an electrostatically balanced cylindrical proofmass accelerometer sensor with three orthogonal sensing axis outputs. The components and functions of the experimental calibration system and signal processor and control subsystem are analyzed. The development of the OARE software is discussed. The experimental equipment will be enclosed in a cover assembly that will be mounted in the Orbiter close to the center of gravity.

  18. Neurodegeneration in accelerated aging.

    PubMed

    Scheibye-Knudsen, Moren

    2016-11-01

    The growing proportion of elderly people represents an increasing economic burden, not least because of age-associated diseases that pose a significant cost to the health service. Finding possible interventions to age-associated disorders therefore have wide ranging implications. A number of genetically defined accelerated aging diseases have been characterized that can aid in our understanding of aging. Interestingly, all these diseases are associated with defects in the maintenance of our genome. A subset of these disorders, Cockayne syndrome, Xeroderma pigmentosum group A and ataxia-telangiectasia, show neurological involvement reminiscent of what is seen in primary human mitochondrial diseases. Mitochondria are the power plants of the cells converting energy stored in oxygen, sugar, fat, and protein into ATP, the energetic currency of our body. Emerging evidence has linked this organelle to aging and finding mitochondrial dysfunction in accelerated aging disorders thereby strengthens the mitochondrial theory of aging. This theory states that an accumulation of damage to the mitochondria may underlie the process of aging. Indeed, it appears that some accelerated aging disorders that show neurodegeneration also have mitochondrial dysfunction. The mitochondrial alterations may be secondary to defects in nuclear DNA repair. Indeed, nuclear DNA damage may lead to increased energy consumption, alterations in mitochondrial ATP production and defects in mitochondrial recycling, a term called mitophagy. These changes may be caused by activation of poly-ADP-ribose-polymerase 1 (PARP1), an enzyme that responds to DNA damage. Upon activation PARP1 utilizes key metabolites that attenuate pathways that are normally protective for the cell. Notably, pharmacological inhibition of PARP1 or reconstitution of the metabolites rescues the changes caused by PARP1 hyperactivation and in many cases reverse the phenotypes associated with accelerated aging. This implies that modulation

  19. Environmental representative program

    SciTech Connect

    McLeod, B.P.

    1984-05-01

    As new pollution regulations are created and existing regulations are made more complex, it is becoming more important for plant personnel to have a knowlege of the environment. The Environmental Representative Program is designed to train plant personnel and is aimed at preventing fines, citations, and negative publicity. The goal of the program is on-going daily compliance assurance, and is divided into two segments: 1) program initiation (general considerations, representative selection, and authorization by management); and 2) program implementation (requirements training, responsibilities development, incorporation into annual goals, and program maintenance). A discussion of how each part of the program is accomplished is presented.

  20. Berkeley Proton Linear Accelerator

    DOE R&D Accomplishments Database

    Alvarez, L. W.; Bradner, H.; Franck, J.; Gordon, H.; Gow, J. D.; Marshall, L. C.; Oppenheimer, F. F.; Panofsky, W. K. H.; Richman, C.; Woodyard, J. R.

    1953-10-13

    A linear accelerator, which increases the energy of protons from a 4 Mev Van de Graaff injector, to a final energy of 31.5 Mev, has been constructed. The accelerator consists of a cavity 40 feet long and 39 inches in diameter, excited at resonance in a longitudinal electric mode with a radio-frequency power of about 2.2 x 10{sup 6} watts peak at 202.5 mc. Acceleration is made possible by the introduction of 46 axial "drift tubes" into the cavity, which is designed such that the particles traverse the distance between the centers of successive tubes in one cycle of the r.f. power. The protons are longitudinally stable as in the synchrotron, and are stabilized transversely by the action of converging fields produced by focusing grids. The electrical cavity is constructed like an inverted airplane fuselage and is supported in a vacuum tank. Power is supplied by 9 high powered oscillators fed from a pulse generator of the artificial transmission line type.

  1. Ultra-Accelerated Natural Sunlight Exposure Testing Facilities

    DOEpatents

    Lewandowski, Allan A.; Jorgensen, Gary J.

    2004-11-23

    A multi-faceted concentrator apparatus for providing ultra-accelerated natural sunlight exposure testing for sample materials under controlled weathering conditions comprising: facets that receive incident natural sunlight, transmits VIS/NIR and reflects UV/VIS onto a secondary reflector that delivers a uniform flux of UV/VIS onto a sample exposure plane located near a center of a facet array in a chamber that provide concurrent levels of temperature and/or relative humidity at high levels of up to 100.times. of natural sunlight that allow sample materials to be subjected to accelerated irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth representative weathering of sample materials.

  2. Ultra-accelerated natural sunlight exposure testing facilities

    DOEpatents

    Lewandowski, Allan A.; Jorgensen, Gary J.

    2003-08-12

    A multi-faceted concentrator apparatus for providing ultra-accelerated natural sunlight exposure testing for sample materials under controlled weathering conditions comprising: facets that receive incident natural sunlight, transmits VIS/NIR and reflects UV/VIS to deliver a uniform flux of UV/VIS onto a sample exposure plane located near a center of a facet array in chamber means that provide concurrent levels of temperature and/or relative humidity at high levels of up to 100.times. of natural sunlight that allow sample materials to be subjected to accelerated irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth representative weathering of sample materials.

  3. VLHC accelerator physics

    SciTech Connect

    Michael Blaskiewicz et al.

    2001-11-01

    A six-month design study for a future high energy hadron collider was initiated by the Fermilab director in October 2000. The request was to study a staged approach where a large circumference tunnel is built that initially would house a low field ({approx}2 T) collider with center-of-mass energy greater than 30 TeV and a peak (initial) luminosity of 10{sup 34} cm{sup -2}s{sup -1}. The tunnel was to be scoped, however, to support a future upgrade to a center-of-mass energy greater than 150 TeV with a peak luminosity of 2 x 10{sup 34} cm{sup -2} sec{sup -1} using high field ({approx} 10 T) superconducting magnet technology. In a collaboration with Brookhaven National Laboratory and Lawrence Berkeley National Laboratory, a report of the Design Study was produced by Fermilab in June 2001. 1 The Design Study focused on a Stage 1, 20 x 20 TeV collider using a 2-in-1 transmission line magnet and leads to a Stage 2, 87.5 x 87.5 TeV collider using 10 T Nb{sub 3}Sn magnet technology. The article that follows is a compilation of accelerator physics designs and computational results which contributed to the Design Study. Many of the parameters found in this report evolved during the study, and thus slight differences between this text and the Design Study report can be found. The present text, however, presents the major accelerator physics issues of the Very Large Hadron Collider as examined by the Design Study collaboration and provides a basis for discussion and further studies of VLHC accelerator parameters and design philosophies.

  4. Accelerator system and method of accelerating particles

    NASA Technical Reports Server (NTRS)

    Wirz, Richard E. (Inventor)

    2010-01-01

    An accelerator system and method that utilize dust as the primary mass flux for generating thrust are provided. The accelerator system can include an accelerator capable of operating in a self-neutralizing mode and having a discharge chamber and at least one ionizer capable of charging dust particles. The system can also include a dust particle feeder that is capable of introducing the dust particles into the accelerator. By applying a pulsed positive and negative charge voltage to the accelerator, the charged dust particles can be accelerated thereby generating thrust and neutralizing the accelerator system.

  5. Progress of Laser-Driven Plasma Accelerators

    SciTech Connect

    Nakajima, Kazuhisa

    2007-07-11

    There is a great interest worldwide in plasma accelerators driven by ultra-intense lasers which make it possible to generate ultra-high gradient acceleration and high quality particle beams in a much more compact size compared with conventional accelerators. A frontier research on laser and plasma accelerators is focused on high energy electron acceleration and ultra-short X-ray and Tera Hertz radiations as their applications. These achievements will provide not only a wide range of sciences with benefits of a table-top accelerator but also a basic science with a tool of ultrahigh energy accelerators probing an unknown extremely microscopic world.Harnessing the recent advance of ultra-intense ultra-short pulse lasers, the worldwide research has made a tremendous breakthrough in demonstrating high-energy high-quality particle beams in a compact scale, so called ''dream beams on a table top'', which represents monoenergetic electron beams from laser wakefield accelerators and GeV acceleration by capillary plasma-channel laser wakefield accelerators. This lecture reviews recent progress of results on laser-driven plasma based accelerator experiments to quest for particle acceleration physics in intense laser-plasma interactions and to present new outlook for the GeV-range high-energy laser plasma accelerators.

  6. Redesigning roles for patient-centered care. The hospitality representative.

    PubMed

    O'Malley, J; Serpico-Thompson, D

    1992-01-01

    Nurses cannot always meet patients' expectations for nonclinical care. The authors describe the operational redesign of several hotel-related functions to enhance the provision of nonclinical care. This system enhances care delivery to better balance patients' perceptions of the clinical with the non-clinical components of care.

  7. Problems in Urban Centers. Oversight Hearings before the Committee on the District of Columbia. House of Representatives, Ninety-Sixth Congress, Second Session on Problems in Urban Centers, Washington, D.C., and the Federal Government Role (June 25, 26, 27, July 23, 24, 30, and September 30, 1980). [Volume I]. Serial No. 96-16.

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. House Committee on the District of Columbia.

    This is a transcript which documents 1980 hearings of the House of Representatives Committee on the District of Columbia. The transcript compares past and present conditions in Washington, D.C. and other American cities; surveys how Federal assistance has helped or hindered the ability of cities to confront urban problems; and explores how Federal…

  8. Accelerated Schools Project Technical Document.

    ERIC Educational Resources Information Center

    Johnson, Janet L.; Donley, Jan

    The North Carolina Partnership for Accelerated Schools includes nine schools in five counties in North Carolina. Representatives from the state Department of Education, the local school agencies, and the teacher educators from North Carolina State University and East Carolina University have worked together to implement the project, which works to…

  9. Centralized digital control of accelerators

    SciTech Connect

    Melen, R.E.

    1983-09-01

    In contrasting the title of this paper with a second paper to be presented at this conference entitled Distributed Digital Control of Accelerators, a potential reader might be led to believe that this paper will focus on systems whose computing intelligence is centered in one or more computers in a centralized location. Instead, this paper will describe the architectural evolution of SLAC's computer based accelerator control systems with respect to the distribution of their intelligence. However, the use of the word centralized in the title is appropriate because these systems are based on the use of centralized large and computationally powerful processors that are typically supported by networks of smaller distributed processors.

  10. Acceleration modules in linear induction accelerators

    NASA Astrophysics Data System (ADS)

    Wang, Shao-Heng; Deng, Jian-Jun

    2014-05-01

    The Linear Induction Accelerator (LIA) is a unique type of accelerator that is capable of accelerating kilo-Ampere charged particle current to tens of MeV energy. The present development of LIA in MHz bursting mode and the successful application into a synchrotron have broadened LIA's usage scope. Although the transformer model is widely used to explain the acceleration mechanism of LIAs, it is not appropriate to consider the induction electric field as the field which accelerates charged particles for many modern LIAs. We have examined the transition of the magnetic cores' functions during the LIA acceleration modules' evolution, distinguished transformer type and transmission line type LIA acceleration modules, and re-considered several related issues based on transmission line type LIA acceleration module. This clarified understanding should help in the further development and design of LIA acceleration modules.

  11. OSMOSE experiment representativity studies.

    SciTech Connect

    Aliberti, G.; Klann, R.; Nuclear Engineering Division

    2007-10-10

    The OSMOSE program aims at improving the neutronic predictions of advanced nuclear fuels through measurements in the MINERVE facility at the CEA-Cadarache (France) on samples containing the following separated actinides: Th-232, U-233, U-234, U-235, U-236, U-238, Np-237, Pu-238, Pu-239, Pu-240, Pu-241, Pu-242, Am-241, Am-243, Cm-244 and Cm-245. The goal of the experimental measurements is to produce a database of reactivity-worth measurements in different neutron spectra for the separated heavy nuclides. This database can then be used as a benchmark for integral reactivity-worth measurements to verify and validate reactor analysis codes and integral cross-section values for the isotopes tested. In particular, the OSMOSE experimental program will produce very accurate sample reactivity-worth measurements for a series of actinides in various spectra, from very thermalized to very fast. The objective of the analytical program is to make use of the experimental data to establish deficiencies in the basic nuclear data libraries, identify their origins, and provide guidelines for nuclear data improvements in coordination with international programs. To achieve the proposed goals, seven different neutron spectra can be created in the MINERVE facility: UO2 dissolved in water (representative of over-moderated LWR systems), UO2 matrix in water (representative of LWRs), a mixed oxide fuel matrix, two thermal spectra containing large epithermal components (representative of under-moderated reactors), a moderated fast spectrum (representative of fast reactors which have some slowing down in moderators such as lead-bismuth or sodium), and a very hard spectrum (representative of fast reactors with little moderation from reactor coolant). The different spectra are achieved by changing the experimental lattice within the MINERVE reactor. The experimental lattice is the replaceable central part of MINERVE, which establishes the spectrum at the sample location. This configuration

  12. Radiation from violently accelerated bodies

    NASA Astrophysics Data System (ADS)

    Gerlach, Ulrich H.

    2001-11-01

    A determination is made of the radiation emitted by a linearly uniformly accelerated uncharged dipole transmitter. It is found that, first of all, the radiation rate is given by the familiar Larmor formula, but it is augmented by an amount which becomes dominant for sufficiently high acceleration. For an accelerated dipole oscillator, the criterion is that the center of mass motion become relativistic within one oscillation period. The augmented formula and the measurements which it summarizes presuppose an expanding inertial observation frame. A static inertial reference frame will not do. Secondly, it is found that the radiation measured in the expanding inertial frame is received with 100% fidelity. There is no blueshift or redshift due to the accelerative motion of the transmitter. Finally, it is found that a pair of coherently radiating oscillators accelerating (into opposite directions) in their respective causally disjoint Rindler-coordinatized sectors produces an interference pattern in the expanding inertial frame. Like the pattern of a Young double slit interferometer, this Rindler interferometer pattern has a fringe spacing which is inversely proportional to the proper separation and the proper frequency of the accelerated sources. The interferometer, as well as the augmented Larmor formula, provide a unifying perspective. It joins adjacent Rindler-coordinatized neighborhoods into a single spacetime arena for scattering and radiation from accelerated bodies.

  13. Progress on plasma accelerators

    SciTech Connect

    Chen, P.

    1986-05-01

    Several plasma accelerator concepts are reviewed, with emphasis on the Plasma Beat Wave Accelerator (PBWA) and the Plasma Wake Field Accelerator (PWFA). Various accelerator physics issues regarding these schemes are discussed, and numerical examples on laboratory scale experiments are given. The efficiency of plasma accelerators is then revealed with suggestions on improvements. Sources that cause emittance growth are discussed briefly.

  14. Rail accelerator technology and applications

    NASA Technical Reports Server (NTRS)

    Zana, L. M.; Kerslake, W. R.

    1985-01-01

    Rail accelerators offer a viable means of launching ton-size payloads from the Earth's surface to space. The results of two mission studies which indicate that an Earth-to-Space Rail Launcher (ESRL) system is not only technically feasible but also economically beneficial, particularly when large amounts of bulk cago are to be delivered to space are given. An in-house experimental program at the Lewis Research Center (LeRC) was conducted in parallel with the mission studies with the objective of examining technical feasibility issues. A 1 m long - 12.5 by 12.5 mm bore rail accelerator as designed with clear polycarbonate sidewalls to visually observe the plasma armature acceleration. The general character of plasma/projectile dynamics is described for a typical test firing.

  15. Excellence in Minority Health Education and Care Act. Hearing on H.R. 954, A Bill to Amend the Public Health Service Act to Authorize Assistance for Centers for Minority Medical Education, Minority Pharmacy Education, Minority Veterinary Medicine Education, and Minority Dentistry Education, before the Subcommittee on Health and the Environment of the Committee on Energy and Commerce, House of Representatives, One Hundredth Congress, First Session.

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. House Committee on Energy and Commerce.

    This document comprises testimony and materials presented at a hearing on H.R. 954, a bill which would provide assistance for centers for minority education in medicine, pharmacy, veterinary medicine, and dentistry. The following individuals presented testimony: (1) Lindy Boggs, a Representative from Louisiana; (2) William Hill Boner, a…

  16. Naked singularities as particle accelerators

    SciTech Connect

    Patil, Mandar; Joshi, Pankaj S.

    2010-11-15

    We investigate here the particle acceleration by naked singularities to arbitrarily high center of mass energies. Recently it has been suggested that black holes could be used as particle accelerators to probe the Planck scale physics. We show that the naked singularities serve the same purpose and probably would do better than their black hole counterparts. We focus on the scenario of a self-similar gravitational collapse starting from a regular initial data, leading to the formation of a globally naked singularity. It is seen that when particles moving along timelike geodesics interact and collide near the Cauchy horizon, the energy of collision in the center of mass frame will be arbitrarily high, thus offering a window to Planck scale physics.

  17. Center Size and Center Performance.

    ERIC Educational Resources Information Center

    Helburn, Suzanne; Morris, John

    1996-01-01

    Examined the impact of child care center size on cost, quality, and profits per child. Examined centers ranging from 40 to 80 children and found total cost and revenue per child were similar for small, medium, and large centers. Found profits per child were highest in large centers and that there was no relationship between center quality and…

  18. "Infotonics Technology Center"

    SciTech Connect

    Fritzemeier, L.; Boysel, M. B.; Smith, D. R.

    2004-09-30

    During this grant period July 15, 2002 thru September 30, 2004, the Infotonics Technology Center developed the critical infrastructure and technical expertise necessary to accelerate the development of sensors, alternative lighting and power sources, and other specific subtopics of interest to Department of Energy. Infotonics fosters collaboration among industry, universities and government and operates as a national center of excellence to drive photonics and microsystems development and commercialization. A main goal of the Center is to establish a unique, world-class research and development facility. A state-of-the-art microsystems prototype and pilot fabrication facility was established to enable rapid commercialization of new products of particular interest to DOE. The Center has three primary areas of photonics and microsystems competency: device research and engineering, packaging and assembly, and prototype and pilot-scale fabrication. Center activities focused on next generation optical communication networks, advanced imaging and information sensors and systems, micro-fluidic systems, assembly and packaging technologies, and biochemical sensors. With targeted research programs guided by the wealth of expertise of Infotonics business and scientific staff, the fabrication and packaging facility supports and accelerates innovative technology development of special interest to DOE in support of its mission and strategic defense, energy, and science goals.

  19. 42 CFR 422.674 - Authority of representatives.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 3 2011-10-01 2011-10-01 false Authority of representatives. 422.674 Section 422.674 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES....674 Authority of representatives. (a) A representative appointed and qualified in accordance...

  20. 42 CFR 422.674 - Authority of representatives.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Authority of representatives. 422.674 Section 422.674 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES....674 Authority of representatives. (a) A representative appointed and qualified in accordance...

  1. Industry Invests in Research Centers.

    ERIC Educational Resources Information Center

    Ploch, Margie

    1983-01-01

    Universities and industry are forging new relationships to support academic research and industrial research and development, including the establishment of university/cooperative research centers. Discusses various cooperative projects at these research centers. Includes a list of representative R&D centers in biotechnology, building…

  2. Future accelerator technology

    SciTech Connect

    Sessler, A.M.

    1986-05-01

    A general discussion is presented of the acceleration of particles. Upon this foundation is built a categorization scheme into which all accelerators can be placed. Special attention is devoted to accelerators which employ a wake-field mechanism and a restricting theorem is examined. It is shown how the theorem may be circumvented. Comments are made on various acceleration schemes.

  3. ACCELERATION AND THE GIFTED.

    ERIC Educational Resources Information Center

    GIBSON, ARTHUR R.; STEPHANS, THOMAS M.

    ACCELERATION OF PUPILS AND SUBJECTS IS CONSIDERED A MEANS OF EDUCATING THE ACADEMICALLY GIFTED STUDENT. FIVE INTRODUCTORY ARTICLES PROVIDE A FRAMEWORK FOR THINKING ABOUT ACCELERATION. FIVE PROJECT REPORTS OF ACCELERATED PROGRAMS IN OHIO ARE INCLUDED. ACCELERATION IS NOW BEING REGARDED MORE FAVORABLY THAN FORMERLY, BECAUSE METHODS HAVE BEEN…

  4. Laser driven ion accelerator

    DOEpatents

    Tajima, Toshiki

    2005-06-14

    A system and method of accelerating ions in an accelerator to optimize the energy produced by a light source. Several parameters may be controlled in constructing a target used in the accelerator system to adjust performance of the accelerator system. These parameters include the material, thickness, geometry and surface of the target.

  5. Laser driven ion accelerator

    DOEpatents

    Tajima, Toshiki

    2006-04-18

    A system and method of accelerating ions in an accelerator to optimize the energy produced by a light source. Several parameters may be controlled in constructing a target used in the accelerator system to adjust performance of the accelerator system. These parameters include the material, thickness, geometry and surface of the target.

  6. Automating linear accelerator quality assurance

    SciTech Connect

    Eckhause, Tobias; Thorwarth, Ryan; Moran, Jean M.; Al-Hallaq, Hania; Farrey, Karl; Ritter, Timothy; DeMarco, John; Pawlicki, Todd; Kim, Gwe-Ya; Popple, Richard; Sharma, Vijeshwar; Park, SungYong; Perez, Mario; Booth, Jeremy T.

    2015-10-15

    Purpose: The purpose of this study was 2-fold. One purpose was to develop an automated, streamlined quality assurance (QA) program for use by multiple centers. The second purpose was to evaluate machine performance over time for multiple centers using linear accelerator (Linac) log files and electronic portal images. The authors sought to evaluate variations in Linac performance to establish as a reference for other centers. Methods: The authors developed analytical software tools for a QA program using both log files and electronic portal imaging device (EPID) measurements. The first tool is a general analysis tool which can read and visually represent data in the log file. This tool, which can be used to automatically analyze patient treatment or QA log files, examines the files for Linac deviations which exceed thresholds. The second set of tools consists of a test suite of QA fields, a standard phantom, and software to collect information from the log files on deviations from the expected values. The test suite was designed to focus on the mechanical tests of the Linac to include jaw, MLC, and collimator positions during static, IMRT, and volumetric modulated arc therapy delivery. A consortium of eight institutions delivered the test suite at monthly or weekly intervals on each Linac using a standard phantom. The behavior of various components was analyzed for eight TrueBeam Linacs. Results: For the EPID and trajectory log file analysis, all observed deviations which exceeded established thresholds for Linac behavior resulted in a beam hold off. In the absence of an interlock-triggering event, the maximum observed log file deviations between the expected and actual component positions (such as MLC leaves) varied from less than 1% to 26% of published tolerance thresholds. The maximum and standard deviations of the variations due to gantry sag, collimator angle, jaw position, and MLC positions are presented. Gantry sag among Linacs was 0.336 ± 0.072 mm. The

  7. BIOCONAID System (Bionic Control of Acceleration Induced Dimming). Final Report.

    ERIC Educational Resources Information Center

    Rogers, Dana B.; And Others

    The system described represents a new technique for enhancing the fidelity of flight simulators during high acceleration maneuvers. This technique forces the simulator pilot into active participation and energy expenditure similar to the aircraft pilot undergoing actual accelerations. The Bionic Control of Acceleration Induced Dimming (BIOCONAID)…

  8. Future HEP Accelerators: The US Perspective

    SciTech Connect

    Bhat, Pushpalatha; Shiltsev, Vladimir

    2015-11-02

    Accelerator technology has advanced tremendously since the introduction of accelerators in the 1930s, and particle accelerators have become indispensable instruments in high energy physics (HEP) research to probe Nature at smaller and smaller distances. At present, accelerator facilities can be classified into Energy Frontier colliders that enable direct discoveries and studies of high mass scale particles and Intensity Frontier accelerators for exploration of extremely rare processes, usually at relatively low energies. The near term strategies of the global energy frontier particle physics community are centered on fully exploiting the physics potential of the Large Hadron Collider (LHC) at CERN through its high-luminosity upgrade (HL-LHC), while the intensity frontier HEP research is focused on studies of neutrinos at the MW-scale beam power accelerator facilities, such as Fermilab Main Injector with the planned PIP-II SRF linac project. A number of next generation accelerator facilities have been proposed and are currently under consideration for the medium- and long-term future programs of accelerator-based HEP research. In this paper, we briefly review the post-LHC energy frontier options, both for lepton and hadron colliders in various regions of the world, as well as possible future intensity frontier accelerator facilities.

  9. Acceleration Environment of the International Space Station

    NASA Technical Reports Server (NTRS)

    McPherson, Kevin; Kelly, Eric; Keller, Jennifer

    2009-01-01

    Measurement of the microgravity acceleration environment on the International Space Station has been accomplished by two accelerometer systems since 2001. The Microgravity Acceleration Measurement System records the quasi-steady microgravity environment, including the influences of aerodynamic drag, vehicle rotation, and venting effects. Measurement of the vibratory/transient regime, comprised of vehicle, crew, and equipment disturbances, has been accomplished by the Space Acceleration Measurement System-II. Until the arrival of the Columbus Orbital Facility and the Japanese Experiment Module, the location of these sensors, and therefore, the measurement of the microgravity acceleration environment, has been limited to within the United States Laboratory. Japanese Aerospace Exploration Agency has developed a vibratory acceleration measurement system called the Microgravity Measurement Apparatus which will be deployed within the Japanese Experiment Module to make distributed measurements of the Japanese Experiment Module's vibratory acceleration environment. Two Space Acceleration Measurement System sensors from the United States Laboratory will be re-deployed to support vibratory acceleration data measurement within the Columbus Orbital Facility. The additional measurement opportunities resulting from the arrival of these new laboratories allows Principal Investigators with facilities located in these International Space Station research laboratories to obtain microgravity acceleration data in support of their sensitive experiments. The Principal Investigator Microgravity Services project, at NASA Glenn Research Center, in Cleveland, Ohio, has supported acceleration measurement systems and the microgravity scientific community through the processing, characterization, distribution, and archival of the microgravity acceleration data obtained from the International Space Station acceleration measurement systems. This paper summarizes the PIMS capabilities available

  10. Center for Beam Physics, 1993

    SciTech Connect

    Not Available

    1994-05-01

    The Center for Beam Physics is a multi-disciplinary research and development unit in the Accelerator and Fusion Research Division at Lawrence Berkeley Laboratory. At the heart of the Center`s mission is the fundamental quest for mechanisms of acceleration, radiation and focusing of energy. Dedicated to exploring the frontiers of the physics of (and with) particle and photon beams, its primary mission is to promote the science and technology of the production, manipulation, storage and control systems of charged particles and photons. The Center serves this mission via conceptual studies, theoretical and experimental research, design and development, institutional project involvement, external collaborations, association with industry and technology transfer. This roster provides a glimpse at the scientists, engineers, technical support, students, and administrative staff that make up this team and a flavor of their multifaceted activities during 1993.

  11. Personal computers in accelerator control

    NASA Astrophysics Data System (ADS)

    Anderssen, P. S.

    1988-07-01

    The advent of the personal computer has created a popular movement which has also made a strong impact on science and engineering. Flexible software environments combined with good computational performance and large storage capacities are becoming available at steadily decreasing costs. Of equal importance, however, is the quality of the user interface offered on many of these products. Graphics and screen interaction is available in ways that were only possible on specialized systems before. Accelerator engineers were quick to pick up the new technology. The first applications were probably for controllers and data gatherers for beam measurement equipment. Others followed, and today it is conceivable to make personal computer a standard component of an accelerator control system. This paper reviews the experience gained at CERN so far and describes the approach taken in the design of the common control center for the SPS and the future LEP accelerators. The design goal has been to be able to integrate personal computers into the accelerator control system and to build the operator's workplace around it.

  12. Crystal structure of the NaCa(Fe{sup 2+}, Al, Mn){sub 5}[Si{sub 8}O{sub 19}(OH)](OH){sub 7} {center_dot} 5H{sub 2}O mineral: A new representative of the palygorskite group

    SciTech Connect

    Rastsvetaeva, R. K. Aksenov, S. M.; Verin, I. A.

    2012-01-15

    A specimen of a new representative of the palygorskite-sepiolite family from Aris phonolite (Namibia) is studied by single-crystal X-ray diffraction. The parameters of the triclinic (pseudomonoclinic) unit cell are as follows: a = 5.2527(2) Angstrom-Sign , b = 17.901(1) Angstrom-Sign , c = 13.727(1) Angstrom-Sign , {alpha} = 90.018(3) Degree-Sign , {beta} = 97.278(4) Degree-Sign , and {gamma} = 89.952(3) Degree-Sign . The structure is solved by the direct methods in space group P1-bar and refined to R = 5.5% for 4168 |F| > 7{sigma}(F) with consideration for twinning by the plane perpendicular to y (the ratio of the twin components is 0.52: 0.48). The crystal chemical formula (Z = 1) is (Na{sub 1.6}K{sub 0.2}Ca{sub 0.2})[Ca{sub 2}(Fe{sub 3.6}{sup 2+}Al{sub 1.6}Mn{sub 0.8})(OH){sub 9}(H{sub 2}O){sub 2}][(Fe{sub 3.9}{sup 2+}Ti{sub 0.1})(OH){sub 5} (H{sub 2}O){sub 2}][Si{sub 16}O{sub 38}(OH){sub 2}] {center_dot} 6H{sub 2}O, where the compositions of two ribbons of octahedra and a layer of Si tetrahedra are enclosed in brackets. A number of specific chemical, symmetrical, and structural features distinguish this mineral from other minerals of this family, in particular, from tuperssuatsiaite and kalifersite, which are iron-containing representatives with close unit cell parameters.

  13. 42 CFR 422.672 - Appointment of representatives.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Appointment of representatives. 422.672 Section 422.672 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES... prohibited by law....

  14. 42 CFR 422.672 - Appointment of representatives.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 3 2012-10-01 2012-10-01 false Appointment of representatives. 422.672 Section 422.672 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES... prohibited by law....

  15. 42 CFR 423.656 - Appointment of representatives.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Appointment of representatives. 423.656 Section 423.656 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES... otherwise prohibited by law....

  16. The Radiological Research Accelerator Facility

    SciTech Connect

    Hall, E.J.; Marino, S.A.

    1993-05-01

    The Radiological Research Accelerator Facility (RARAF) is based on a 4-MV Van de Graaff accelerator, which is used to generate a variety of well-characterized radiation beams for research in radiobiology, radiological physics, and radiation chemistry. It is part of the Center for Radiological Research (CRR) - formerly the Radiological Research Laboratory of Columbia University, and its operation is supported as a National Facility by the US Department of Energy (DOE). As such, RARAF is available to all potential users on an equal basis and scientists outside the CRR are encouraged to submit proposals for experiments at RARAF. The operation of the Van de Graaff is supported by the DOE, but the research projects themselves must be supported separately. This report provides a listing and brief description of experiments performed at RARAF during the May 1, 1992 through April 30, 1993.

  17. The Radiological Research Accelerator Facility

    SciTech Connect

    Hall, E.J.

    1992-05-01

    The Radiological Research Accelerator Facility (RARAF) is based on a 4-MV Van de Graaff accelerator, which is used to generate a variety of well-characterized radiation beams for research in radiobiology, radiological physics, and radiation chemistry. It is part of the Center for Radiological Research (CRR) -- formerly the Radiological Research Laboratory (RRL) -- of Columbia University, and its operation is supported as a National Facility by the US Department of Energy (DOE). As such, RARAF is available to all potential users on an equal basis, and scientists outside the CRR are encouraged to submit proposals for experiments at RARAF. The operation of the Van de Graaff is supported by the DOE, but the research projects themselves must be supported separately. Experiments performed from May 1991--April 1992 are described.

  18. Accelerating Particles with Plasma

    ScienceCinema

    Litos, Michael; Hogan, Mark

    2016-07-12

    Researchers at SLAC explain how they use plasma wakefields to accelerate bunches of electrons to very high energies over only a short distance. Their experiments offer a possible path for the future of particle accelerators.

  19. Peak acceleration limiter

    NASA Technical Reports Server (NTRS)

    Chapman, C. P.

    1972-01-01

    Device is described that limits accelerations by shutting off shaker table power very rapidly in acceleration tests. Absolute value of accelerometer signal is used to trigger electronic switch which terminates test and sounds alarm.

  20. Linear Accelerator (LINAC)

    MedlinePlus

    ... equipment? How is safety ensured? What is this equipment used for? A linear accelerator (LINAC) is the ... Therapy (SBRT) . top of page How does the equipment work? The linear accelerator uses microwave technology (similar ...

  1. Accelerating Particles with Plasma

    SciTech Connect

    Litos, Michael; Hogan, Mark

    2014-11-05

    Researchers at SLAC explain how they use plasma wakefields to accelerate bunches of electrons to very high energies over only a short distance. Their experiments offer a possible path for the future of particle accelerators.

  2. Improved plasma accelerator

    NASA Technical Reports Server (NTRS)

    Cheng, D. Y.

    1971-01-01

    Converging, coaxial accelerator electrode configuration operates in vacuum as plasma gun. Plasma forms by periodic injections of high pressure gas that is ionized by electrical discharges. Deflagration mode of discharge provides acceleration, and converging contours of plasma gun provide focusing.

  3. Accelerator Technology Division

    NASA Astrophysics Data System (ADS)

    1992-04-01

    In fiscal year (FY) 1991, the Accelerator Technology (AT) division continued fulfilling its mission to pursue accelerator science and technology and to develop new accelerator concepts for application to research, defense, energy, industry, and other areas of national interest. This report discusses the following programs: The Ground Test Accelerator Program; APLE Free-Electron Laser Program; Accelerator Transmutation of Waste; JAERI, OMEGA Project, and Intense Neutron Source for Materials Testing; Advanced Free-Electron Laser Initiative; Superconducting Super Collider; The High-Power Microwave Program; (Phi) Factory Collaboration; Neutral Particle Beam Power System Highlights; Accelerator Physics and Special Projects; Magnetic Optics and Beam Diagnostics; Accelerator Design and Engineering; Radio-Frequency Technology; Free-Electron Laser Technology; Accelerator Controls and Automation; Very High-Power Microwave Sources and Effects; and GTA Installation, Commissioning, and Operations.

  4. Kinematics of transition during human accelerated sprinting

    PubMed Central

    Nagahara, Ryu; Matsubayashi, Takeo; Matsuo, Akifumi; Zushi, Koji

    2014-01-01

    ABSTRACT This study investigated kinematics of human accelerated sprinting through 50 m and examined whether there is transition and changes in acceleration strategies during the entire acceleration phase. Twelve male sprinters performed a 60-m sprint, during which step-to-step kinematics were captured using 60 infrared cameras. To detect the transition during the acceleration phase, the mean height of the whole-body centre of gravity (CG) during the support phase was adopted as a measure. Detection methods found two transitions during the entire acceleration phase of maximal sprinting, and the acceleration phase could thus be divided into initial, middle, and final sections. Discriminable kinematic changes were found when the sprinters crossed the detected first transition—the foot contacting the ground in front of the CG, the knee-joint starting to flex during the support phase, terminating an increase in step frequency—and second transition—the termination of changes in body postures and the start of a slight decrease in the intensity of hip-joint movements, thus validating the employed methods. In each acceleration section, different contributions of lower-extremity segments to increase in the CG forward velocity—thigh and shank for the initial section, thigh, shank, and foot for the middle section, shank and foot for the final section—were verified, establishing different acceleration strategies during the entire acceleration phase. In conclusion, there are presumably two transitions during human maximal accelerated sprinting that divide the entire acceleration phase into three sections, and different acceleration strategies represented by the contributions of the segments for running speed are employed. PMID:24996923

  5. Parametric approach to linear induction accelerator design

    SciTech Connect

    Bresie, D.A.; Andrews, J.A.; Ingram, S.W. . Center for Electromechanics)

    1991-01-01

    Past work on the design of linear induction accelerators has centered on the development of computer codes to analyze accelerator designs, using the current filament method. While these filament models are a very valuable tool for evaluating the performance of an induction launcher design, they provide little insight into the selection of dimensions, materials, and operation points for accelerators with interesting performance. Described in this paper is a parametric approach to defining effective accelerator designs. This method uses a computer optimization routine to iteratively seek out effective designs. The optimization routine is forced to search within a parameter space restricted to interesting and realistic parameters such as size, weight, voltage, and temperature rises. A filament model is used as the filter for the optimizer. Several linear induction accelerators have been designed using this method. The accelerators designed all used a switched capacitor power supply. While the run time of this code on The University of Texas' CRAY XMP-24 computer is moderately long, the resulting designs have good predicted performance. With realistic power supplies and materials, accelerator efficiencies in the 20 to 40% range were easily obtained. This paper describes the effect of armature diameter, length-to-diameter ratio, and weight, as well as other parameters, on the optimum accelerator design.

  6. Accelerators, Colliders, and Snakes

    NASA Astrophysics Data System (ADS)

    Courant, Ernest D.

    2003-12-01

    The author traces his involvement in the evolution of particle accelerators over the past 50 years. He participated in building the first billion-volt accelerator, the Brookhaven Cosmotron, which led to the introduction of the "strong-focusing" method that has in turn led to the very large accelerators and colliders of the present day. The problems of acceleration of spin-polarized protons are also addressed, with discussions of depolarizing resonances and "Siberian snakes" as a technique for mitigating these resonances.

  7. Under-Representation in Nationally Representative Secondary Data

    ERIC Educational Resources Information Center

    Frederick, Karen; Barnard-Brak, Lucy; Sulak, Tracey

    2012-01-01

    There has been a significant increase in the use of secondary data sets. Many such data sets purport to be nationally representative. Secondary data sets include research commissioned by the National Center for Education Statistics, the Centers for Disease Control, and other public entities. Research increasingly utilizes these secondary data in…

  8. View northeast of model board representing northern portion of trackage ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View northeast of model board representing northern portion of trackage monitored by the Philadelphia poer directors center; free-standing cabinet at far right center of photograph is an early computer which supplanted operator control from Lamokin Tower in the 1980's; switchboard console #1 for controlling indicating lights is at lower right - Thirtieth Street Station, Power Director Center, Thirtieth & Market Streets in Amtrak Railroad Station, Philadelphia, Philadelphia County, PA

  9. Compact plasma accelerator

    NASA Technical Reports Server (NTRS)

    Foster, John E. (Inventor)

    2004-01-01

    A compact plasma accelerator having components including a cathode electron source, an anodic ionizing gas source, and a magnetic field that is cusped. The components are held by an electrically insulating body having a central axis, a top axial end, and a bottom axial end. The cusped magnetic field is formed by a cylindrical magnet having an axis of rotation that is the same as the axis of rotation of the insulating body, and magnetized with opposite poles at its two axial ends; and an annular magnet coaxially surrounding the cylindrical magnet, magnetized with opposite poles at its two axial ends such that a top axial end has a magnetic polarity that is opposite to the magnetic polarity of a top axial end of the cylindrical magnet. The ionizing gas source is a tubular plenum that has been curved into a substantially annular shape, positioned above the top axial end of the annular magnet such that the plenum is centered in a ring-shaped cusp of the magnetic field generated by the magnets. The plenum has one or more capillary-like orifices spaced around its top such that an ionizing gas supplied through the plenum is sprayed through the one or more orifices. The plenum is electrically conductive and is positively charged relative to the cathode electron source such that the plenum functions as the anode; and the cathode is positioned above and radially outward relative to the plenum.

  10. Acceleration: It's Elementary

    ERIC Educational Resources Information Center

    Willis, Mariam

    2012-01-01

    Acceleration is one tool for providing high-ability students the opportunity to learn something new every day. Some people talk about acceleration as taking a student out of step. In actuality, what one is doing is putting a student in step with the right curriculum. Whole-grade acceleration, also called grade-skipping, usually happens between…

  11. Accelerated test design

    NASA Technical Reports Server (NTRS)

    Mcdermott, P. P.

    1980-01-01

    The design of an accelerated life test program for electric batteries is discussed. A number of observations and suggestions on the procedures and objectives for conducting an accelerated life test program are presented. Equations based on nonlinear regression analysis for predicting the accelerated life test parameters are discussed.

  12. Systems and methods for the magnetic insulation of accelerator electrodes in electrostatic accelerators

    DOEpatents

    Grisham, Larry R

    2013-12-17

    The present invention provides systems and methods for the magnetic insulation of accelerator electrodes in electrostatic accelerators. Advantageously, the systems and methods of the present invention improve the practically obtainable performance of these electrostatic accelerators by addressing, among other things, voltage holding problems and conditioning issues. The problems and issues are addressed by flowing electric currents along these accelerator electrodes to produce magnetic fields that envelope the accelerator electrodes and their support structures, so as to prevent very low energy electrons from leaving the surfaces of the accelerator electrodes and subsequently picking up energy from the surrounding electric field. In various applications, this magnetic insulation must only produce modest gains in voltage holding capability to represent a significant achievement.

  13. NREL National Bioenergy Center Overview

    SciTech Connect

    Foust, Thomas; Pienkos, Phil; Sluiter, Justin; Magrini, Kim; McMillan, Jim

    2014-07-28

    The demand for clean, sustainable, secure energy is growing... and the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) is answering the call. NREL's National Bioenergy Center is pioneering biofuels research and development and accelerating the pace these technologies move into the marketplace.

  14. NREL National Bioenergy Center Overview

    ScienceCinema

    Foust, Thomas; Pienkos, Phil; Sluiter, Justin; Magrini, Kim; McMillan, Jim

    2016-07-12

    The demand for clean, sustainable, secure energy is growing... and the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) is answering the call. NREL's National Bioenergy Center is pioneering biofuels research and development and accelerating the pace these technologies move into the marketplace.

  15. The underground electromagnetic pulse: Four representative models

    SciTech Connect

    Wouters, L.F.

    1989-06-01

    I describe four phenomenological models by which an underground nuclear explosion may generate electromagnetic pulses: Compton current asymmetry (or ''Compton dipole''); Uphole conductor currents (or ''casing currents''); Diamagnetic cavity plasma (or ''magnetic bubble''); and Large-scale ground motion (or ''magneto-acoustic wave''). I outline the corresponding analytic exercises and summarize the principal results of the computations. I used a 10-kt contained explosion as the fiducial case. Each analytic sequence developed an equivalent source dipole and calculated signal waveforms at representative ground-surface locations. As a comparative summary, the Compton dipole generates a peak source current moment of about 12,000 A/center dot/m in the submicrosecond time domain. The casing-current source model obtains an equivalent peak moment of about 2 /times/ 10/sup 5/ A/center dot/m in the 10- to 30-/mu/s domain. The magnetic bubble produces a magnetic dipole moment of about 7 /times/ 10/sup 6/ A/center dot/m/sup 2/, characterized by a 30-ms time structure. Finally, the magneto-acoustic wave corresponds to a magnetic dipole moment of about 600 A/center dot/m/sup 2/, with a waveform showing 0.5-s periodicities. 8 refs., 35 figs., 7 tabs.

  16. Fiber Accelerating Structures

    SciTech Connect

    Hammond, Andrew P.; /Reed Coll. /SLAC

    2010-08-25

    One of the options for future particle accelerators are photonic band gap (PBG) fiber accelerators. PBG fibers are specially designed optical fibers that use lasers to excite an electric field that is used to accelerate electrons. To improve PBG accelerators, the basic parameters of the fiber were tested to maximize defect size and acceleration. Using the program CUDOS, several accelerating modes were found that maximized these parameters for several wavelengths. The design of multiple defects, similar to having closely bound fibers, was studied to find possible coupling or the change of modes. The amount of coupling was found to be dependent on distance separated. For certain distances accelerating coupled modes were found and examined. In addition, several non-periodic fiber structures were examined using CUDOS. The non-periodic fibers produced several interesting results and promised more modes given time to study them in more detail.

  17. High brightness electron accelerator

    DOEpatents

    Sheffield, Richard L.; Carlsten, Bruce E.; Young, Lloyd M.

    1994-01-01

    A compact high brightness linear accelerator is provided for use, e.g., in a free electron laser. The accelerator has a first plurality of acclerating cavities having end walls with four coupling slots for accelerating electrons to high velocities in the absence of quadrupole fields. A second plurality of cavities receives the high velocity electrons for further acceleration, where each of the second cavities has end walls with two coupling slots for acceleration in the absence of dipole fields. The accelerator also includes a first cavity with an extended length to provide for phase matching the electron beam along the accelerating cavities. A solenoid is provided about the photocathode that emits the electons, where the solenoid is configured to provide a substantially uniform magnetic field over the photocathode surface to minimize emittance of the electons as the electrons enter the first cavity.

  18. An accelerated line-by-line option for MODTRAN combining on-the-fly generation of line center absorption within 0.1 cm-1 bins and pre-computed line tails

    NASA Astrophysics Data System (ADS)

    Berk, Alexander; Conforti, Patrick; Hawes, Fred

    2015-05-01

    A Line-By-Line (LBL) option is being developed for MODTRAN6. The motivation for this development is two-fold. Firstly, when MODTRAN is validated against an independent LBL model, it is difficult to isolate the source of discrepancies. One must verify consistency between pressure, temperature and density profiles, between column density calculations, between continuum and particulate data, between spectral convolution methods, and more. Introducing a LBL option directly within MODTRAN will insure common elements for all calculations other than those used to compute molecular transmittances. The second motivation for the LBL upgrade is that it will enable users to compute high spectral resolution transmittances and radiances for the full range of current MODTRAN applications. In particular, introducing the LBL feature into MODTRAN will enable first-principle calculations of scattered radiances, an option that is often not readily available with LBL models. MODTRAN will compute LBL transmittances within one 0.1 cm-1 spectral bin at a time, marching through the full requested band pass. The LBL algorithm will use the highly accurate, pressure- and temperature-dependent MODTRAN Padé approximant fits of the contribution from line tails to define the absorption from all molecular transitions centered more than 0.05 cm-1 from each 0.1 cm-1 spectral bin. The beauty of this approach is that the on-the-fly computations for each 0.1 cm-1 bin will only require explicit LBL summing of transitions centered within a 0.2 cm-1 spectral region. That is, the contribution from the more distant lines will be pre-computed via the Padé approximants. The status of the LBL effort will be presented. This will include initial thermal and solar radiance calculations, validation calculations, and self-validations of the MODTRAN band model against its own LBL calculations.

  19. 42 CFR 422.1008 - Appointment of representatives.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 3 2012-10-01 2012-10-01 false Appointment of representatives. 422.1008 Section 422.1008 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN... Secretary or otherwise prohibited by law. (b) If the representative appointed is not an attorney, the...

  20. 42 CFR 423.1008 - Appointment of representatives.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 3 2012-10-01 2012-10-01 false Appointment of representatives. 423.1008 Section 423.1008 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN... proceedings before the Secretary or otherwise prohibited by law. (b) If the representative appointed is not...

  1. 42 CFR 498.10 - Appointment of representatives.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 5 2013-10-01 2013-10-01 false Appointment of representatives. 498.10 Section 498.10 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES... representative in proceedings before the Secretary or otherwise prohibited by law. (b) If the...

  2. 42 CFR 441.735 - Definition of individual's representative.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 4 2014-10-01 2014-10-01 false Definition of individual's representative. 441.735 Section 441.735 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN... representative, the individual will lead the service planning process to the extent possible. (b) Any...

  3. Acceleration in astrophysics

    SciTech Connect

    Colgate, S.A.

    1993-12-31

    The origin of cosmic rays and applicable laboratory experiments are discussed. Some of the problems of shock acceleration for the production of cosmic rays are discussed in the context of astrophysical conditions. These are: The presumed unique explanation of the power law spectrum is shown instead to be a universal property of all lossy accelerators; the extraordinary isotropy of cosmic rays and the limited diffusion distances implied by supernova induced shock acceleration requires a more frequent and space-filling source than supernovae; the near perfect adiabaticity of strong hydromagnetic turbulence necessary for reflecting the accelerated particles each doubling in energy roughly 10{sup 5} to {sup 6} scatterings with negligible energy loss seems most unlikely; the evidence for acceleration due to quasi-parallel heliosphere shocks is weak. There is small evidence for the expected strong hydromagnetic turbulence, and instead, only a small number of particles accelerate after only a few shock traversals; the acceleration of electrons in the same collisionless shock that accelerates ions is difficult to reconcile with the theoretical picture of strong hydromagnetic turbulence that reflects the ions. The hydromagnetic turbulence will appear adiabatic to the electrons at their much higher Larmor frequency and so the electrons should not be scattered incoherently as they must be for acceleration. Therefore the electrons must be accelerated by a different mechanism. This is unsatisfactory, because wherever electrons are accelerated these sites, observed in radio emission, may accelerate ions more favorably. The acceleration is coherent provided the reconnection is coherent, in which case the total flux, as for example of collimated radio sources, predicts single charge accelerated energies much greater than observed.

  4. Accelerator & Fusion Research Division 1991 summary of activities

    SciTech Connect

    Not Available

    1991-12-01

    This report discusses research projects in the following areas: Heavy-ion fusion accelerator research; magnetic fusion energy; advanced light source; center for x-ray optics; exploratory studies; superconducting magnets; and bevalac operations.

  5. Accelerator Fusion Research Division 1991 summary of activities

    SciTech Connect

    Berkner, Klaus H.

    1991-12-01

    This report discusses research projects in the following areas: Heavy-ion fusion accelerator research; magnetic fusion energy; advanced light source; center for x-ray optics; exploratory studies; superconducting magnets; and bevalac operations.

  6. Accelerator and fusion research division. 1992 Summary of activities

    SciTech Connect

    Not Available

    1992-12-01

    This report contains brief discussions on research topics in the following area: Heavy-Ion Fusion Accelerator Research; Magnetic Fusion Energy; Advanced Light Source; Center for Beam Physics; Superconducting Magnets; and Bevalac Operations.

  7. Representing Tactical Land Navigation Expertise

    DTIC Science & Technology

    2000-09-01

    they adjust and recalibrate tools dynamically; and (4) they visualize spatial information. Finally, a multi - agent system computationally represents the route planning portion of the performance model.

  8. Accelerator and Fusion Research Division: Summary of activities, 1986

    SciTech Connect

    Not Available

    1987-04-15

    This report contains a summary of activities at the Lawrence Berkeley Laboratory's Accelerator and Fusion Research Division for the year 1986. Topics and facilities investigated in individual papers are: 1-2 GeV Synchrotron Radiation Source, the Center for X-Ray Optics, Accelerator Operations, High-Energy Physics Technology, Heavy-Ion Fusion Accelerator Research and Magnetic Fusion Energy. Six individual papers have been indexed separately. (LSP)

  9. Accelerator and Fusion Research Division 1989 summary of activities

    SciTech Connect

    Not Available

    1990-06-01

    This report discusses the research being conducted at Lawrence Berkeley Laboratory's Accelerator and Fusion Research Division. The main topics covered are: heavy-ion fusion accelerator research; magnetic fusion energy; advanced light source; center for x-ray optics; exploratory studies; high-energy physics technology; and bevalac operations.

  10. Representing operations procedures using temporal dependency networks

    NASA Technical Reports Server (NTRS)

    Fayyad, Kristina E.; Cooper, Lynne P.

    1993-01-01

    DSN Link Monitor & Control (LMC) operations consist primarily of executing procedures to configure, calibrate, test, and operate a communications link between an interplanetary spacecraft and its mission control center. Currently the LMC operators are responsible for integrating procedures into an end-to-end series of steps. The research presented in this paper is investigating new ways of specifying operations procedures that incorporate the insight of operations, engineering, and science personnel to improve mission operations. The paper describes the rationale for using Temporal Dependency Networks (TDN's) to represent the procedures, a description of how the data is acquired, and the knowledge engineering effort required to represent operations procedures. Results of operational tests of this concept, as implemented in the LMC Operator Assistant Prototype (LMCOA), are also presented.

  11. An introduction to acceleration mechanisms

    SciTech Connect

    Palmer, R.B.

    1987-05-01

    This paper discusses the acceleration of charged particles by electromagnetic fields, i.e., by fields that are produced by the motion of other charged particles driven by some power source. The mechanisms that are discussed include: Ponderamotive Forces, Acceleration, Plasma Beat Wave Acceleration, Inverse Free Electron Laser Acceleration, Inverse Cerenkov Acceleration, Gravity Acceleration, 2D Linac Acceleration and Conventional Iris Loaded Linac Structure Acceleration. (LSP)

  12. [Proton therapy and particle accelerators].

    PubMed

    Fukumoto, Sadayoshi

    2012-01-01

    Since the high energy accelerator plan was changed from a 40 GeV direct machine to a 12GeV cascade one, a 500 MeV rapid cycling booster synchrotron was installed between the injector linac and the 12 GeV main ring at KEK, National Lab. for High Energy Physics. The booster beams were used not only for injection to the main ring but also for medical use. Their energy was reduced to 250 MeV by a graphite block for clinical trial of cancer therapy. In 1970's, pi(-) or heavy ions were supposed to be promising. Although advantage of protons with Bragg Peak was pointed out earlier, they seemed effective only for eye melanoma at that time. In early 1980's, it was shown that they were effective for deep-seated tumor by Tsukuba University with KEK beams. The first dedicated facility was built at Loma Linda University Medical Center. Its synchrotron was made by Fermi National Accelerator Lab. Since a non-resonant accelerating rf cavity was installed, operation of the synchrotron became much easier. Later, innovation of the cyclotron was achieved. Its weight was reduced from 1,000 ton to 200 ton. Some of the cyclotrons are equipped with superconducting coils.

  13. Schooling in Times of Acceleration

    ERIC Educational Resources Information Center

    Buddeberg, Magdalena; Hornberg, Sabine

    2017-01-01

    Modern societies are characterised by forms of acceleration, which influence social processes. Sociologist Hartmut Rosa has systematised temporal structures by focusing on three categories of social acceleration: technical acceleration, acceleration of social change, and acceleration of the pace of life. All three processes of acceleration are…

  14. Iowa Acceleration Scale Manual: A Guide for Whole-Grade Acceleration K-8. (3rd Edition, Manual)

    ERIC Educational Resources Information Center

    Assouline, Susan G.; Colangelo, Nicholas; Lupkowski-Shoplik, Ann; Forstadt, Leslie; Lipscomb, Jonathon

    2009-01-01

    Feedback from years of nationwide use has resulted in a 3rd Edition of this unique, systematic, and objective guide to considering and implementing academic acceleration. Developed and tested by the Belin-Blank Center at the University of Iowa, the IAS ensures that acceleration decisions are systematic, thoughtful, well reasoned, and defensible.…

  15. Uniformly accelerated black holes

    NASA Astrophysics Data System (ADS)

    Letelier, Patricio S.; Oliveira, Samuel R.

    2001-09-01

    The static and stationary C metric are examined in a generic framework and their interpretations studied in some detail, especially those with two event horizons, one for the black hole and another for the acceleration. We find that (i) the spacetime of an accelerated static black hole is plagued by either conical singularities or a lack of smoothness and compactness of the black hole horizon, (ii) by using standard black hole thermodynamics we show that accelerated black holes have a higher Hawking temperature than Unruh temperature of the accelerated frame, and (iii) the usual upper bound on the product of the mass and acceleration parameters (<1/27) is just a coordinate artifact. The main results are extended to accelerated rotating black holes with no significant changes.

  16. The Dielectric Wall Accelerator

    SciTech Connect

    Caporaso, George J.; Chen, Yu-Jiuan; Sampayan, Stephen E.

    2009-01-01

    The Dielectric Wall Accelerator (DWA), a class of induction accelerators, employs a novel insulating beam tube to impress a longitudinal electric field on a bunch of charged particles. The surface flashover characteristics of this tube may permit the attainment of accelerating gradients on the order of 100 MV/m for accelerating pulses on the order of a nanosecond in duration. A virtual traveling wave of excitation along the tube is produced at any desired speed by controlling the timing of pulse generating modules that supply a tangential electric field to the tube wall. Because of the ability to control the speed of this virtual wave, the accelerator is capable of handling any charge to mass ratio particle; hence it can be used for electrons, protons and any ion. The accelerator architectures, key technologies and development challenges will be described.

  17. Applications of the Strategic Defense Initiative's compact accelerators

    NASA Technical Reports Server (NTRS)

    Montanarelli, Nick; Lynch, Ted

    1991-01-01

    The Strategic Defense Initiative's (SDI) investment in particle accelerator technology for its directed energy weapons program has produced breakthroughs in the size and power of new accelerators. These accelerators, in turn, have produced spinoffs in several areas: the radio frequency quadrupole linear accelerator (RFQ linac) was recently incorporated into the design of a cancer therapy unit at the Loma Linda University Medical Center, an SDI-sponsored compact induction linear accelerator may replace Cobalt-60 radiation and hazardous ethylene-oxide as a method for sterilizing medical products, and other SDIO-funded accelerators may be used to produce the radioactive isotopes oxygen-15, nitrogen-13, carbon-11, and fluorine-18 for positron emission tomography (PET). Other applications of these accelerators include bomb detection, non-destructive inspection, decomposing toxic substances in contaminated ground water, and eliminating nuclear waste.

  18. Optically pulsed electron accelerator

    DOEpatents

    Fraser, J.S.; Sheffield, R.L.

    1985-05-20

    An optically pulsed electron accelerator can be used as an injector for a free electron laser and comprises a pulsed light source, such as a laser, for providing discrete incident light pulses. A photoemissive electron source emits electron bursts having the same duration as the incident light pulses when impinged upon by same. The photoemissive electron source is located on an inside wall of a radiofrequency-powered accelerator cell which accelerates the electron burst emitted by the photoemissive electron source.

  19. Optically pulsed electron accelerator

    DOEpatents

    Fraser, John S.; Sheffield, Richard L.

    1987-01-01

    An optically pulsed electron accelerator can be used as an injector for a free electron laser and comprises a pulsed light source, such as a laser, for providing discrete incident light pulses. A photoemissive electron source emits electron bursts having the same duration as the incident light pulses when impinged upon by same. The photoemissive electron source is located on an inside wall of a radio frequency powered accelerator cell which accelerates the electron burst emitted by the photoemissive electron source.

  20. ACCELERATION RESPONSIVE SWITCH

    DOEpatents

    Chabrek, A.F.; Maxwell, R.L.

    1963-07-01

    An acceleration-responsive device with dual channel capabilities whereby a first circuit is actuated upon attainment of a predetermined maximum acceleration level and when the acceleration drops to a predetermined minimum acceleriltion level another circuit is actuated is described. A fluid-damped sensing mass slidably mounted in a relatively frictionless manner on a shaft through the intermediation of a ball bushing and biased by an adjustable compression spring provides inertially operated means for actuating the circuits. (AEC)

  1. The foxhole accelerating structure

    SciTech Connect

    Fernow, R.C.; Claus, J.

    1992-07-17

    This report examines some properties of a new type of open accelerating structure. It consists of a series of rectangular cavities, which we call foxholes, joined by a beam channel. The power for accelerating the particles comes from an external radiation source and enters the cavities through their open upper surfaces. Analytic and computer calculations are presented showing that the foxhole is a suitable structure for accelerating relativistic electrons.

  2. Particle acceleration in flares

    NASA Technical Reports Server (NTRS)

    Benz, Arnold O.; Kosugi, Takeo; Aschwanden, Markus J.; Benka, Steve G.; Chupp, Edward L.; Enome, Shinzo; Garcia, Howard; Holman, Gordon D.; Kurt, Victoria G.; Sakao, Taro

    1994-01-01

    Particle acceleration is intrinsic to the primary energy release in the impulsive phase of solar flares, and we cannot understand flares without understanding acceleration. New observations in soft and hard X-rays, gamma-rays and coherent radio emissions are presented, suggesting flare fragmentation in time and space. X-ray and radio measurements exhibit at least five different time scales in flares. In addition, some new observations of delayed acceleration signatures are also presented. The theory of acceleration by parallel electric fields is used to model the spectral shape and evolution of hard X-rays. The possibility of the appearance of double layers is further investigated.

  3. Charged particle accelerator grating

    DOEpatents

    Palmer, Robert B.

    1986-01-01

    A readily disposable and replaceable accelerator grating for a relativistic particle accelerator. The grating is formed for a plurality of liquid droplets that are directed in precisely positioned jet streams to periodically dispose rows of droplets along the borders of a predetermined particle beam path. A plurality of lasers are used to direct laser beams into the droplets, at predetermined angles, thereby to excite the droplets to support electromagnetic accelerating resonances on their surfaces. Those resonances operate to accelerate and focus particles moving along the beam path. As the droplets are distorted or destroyed by the incoming radiation, they are replaced at a predetermined frequency by other droplets supplied through the jet streams.

  4. Charged particle accelerator grating

    DOEpatents

    Palmer, Robert B.

    1986-09-02

    A readily disposable and replaceable accelerator grating for a relativistic particle accelerator. The grating is formed for a plurality of liquid droplets that are directed in precisely positioned jet streams to periodically dispose rows of droplets along the borders of a predetermined particle beam path. A plurality of lasers are used to direct laser beams into the droplets, at predetermined angles, thereby to excite the droplets to support electromagnetic accelerating resonances on their surfaces. Those resonances operate to accelerate and focus particles moving along the beam path. As the droplets are distorted or destroyed by the incoming radiation, they are replaced at a predetermined frequency by other droplets supplied through the jet streams.

  5. Accelerator-based BNCT.

    PubMed

    Kreiner, A J; Baldo, M; Bergueiro, J R; Cartelli, D; Castell, W; Thatar Vento, V; Gomez Asoia, J; Mercuri, D; Padulo, J; Suarez Sandin, J C; Erhardt, J; Kesque, J M; Valda, A A; Debray, M E; Somacal, H R; Igarzabal, M; Minsky, D M; Herrera, M S; Capoulat, M E; Gonzalez, S J; del Grosso, M F; Gagetti, L; Suarez Anzorena, M; Gun, M; Carranza, O

    2014-06-01

    The activity in accelerator development for accelerator-based BNCT (AB-BNCT) both worldwide and in Argentina is described. Projects in Russia, UK, Italy, Japan, Israel, and Argentina to develop AB-BNCT around different types of accelerators are briefly presented. In particular, the present status and recent progress of the Argentine project will be reviewed. The topics will cover: intense ion sources, accelerator tubes, transport of intense beams, beam diagnostics, the (9)Be(d,n) reaction as a possible neutron source, Beam Shaping Assemblies (BSA), a treatment room, and treatment planning in realistic cases.

  6. High Gradient Accelerator Research

    SciTech Connect

    Temkin, Richard

    2016-07-12

    The goal of the MIT program of research on high gradient acceleration is the development of advanced acceleration concepts that lead to a practical and affordable next generation linear collider at the TeV energy level. Other applications, which are more near-term, include accelerators for materials processing; medicine; defense; mining; security; and inspection. The specific goals of the MIT program are: • Pioneering theoretical research on advanced structures for high gradient acceleration, including photonic structures and metamaterial structures; evaluation of the wakefields in these advanced structures • Experimental research to demonstrate the properties of advanced structures both in low-power microwave cold test and high-power, high-gradient test at megawatt power levels • Experimental research on microwave breakdown at high gradient including studies of breakdown phenomena induced by RF electric fields and RF magnetic fields; development of new diagnostics of the breakdown process • Theoretical research on the physics and engineering features of RF vacuum breakdown • Maintaining and improving the Haimson / MIT 17 GHz accelerator, the highest frequency operational accelerator in the world, a unique facility for accelerator research • Providing the Haimson / MIT 17 GHz accelerator facility as a facility for outside users • Active participation in the US DOE program of High Gradient Collaboration, including joint work with SLAC and with Los Alamos National Laboratory; participation of MIT students in research at the national laboratories • Training the next generation of Ph. D. students in the field of accelerator physics.

  7. FFAGS for rapid acceleration

    SciTech Connect

    Carol J. Johnstone and Shane Koscielniak

    2002-09-30

    When large transverse and longitudinal emittances are to be transported through a circular machine, extremely rapid acceleration holds the advantage that the beam becomes immune to nonlinear resonances because there is insufficient time for amplitudes to build up. Uncooled muon beams exhibit large emittances and require fast acceleration to avoid decay losses and would benefit from this style of acceleration. The approach here employs a fixed-field alternating gradient or FFAG magnet structure and a fixed frequency acceleration system. Acceptance is enhanced by the use only of linear lattice elements, and fixed-frequency rf enables the use of cavities with large shunt resistance and quality factor.

  8. Acceleration of polarized protons in circular accelerators

    SciTech Connect

    Courant, E.D.; Ruth, R.D.

    1980-09-12

    The theory of depolarization in circular accelerators is presented. The spin equation is first expressed in terms of the particle orbit and then converted to the equivalent spinor equation. The spinor equation is then solved for three different situations: (1) a beam on a flat top near a resonance, (2) uniform acceleration through an isolated resonance, and (3) a model of a fast resonance jump. Finally, the depolarization coefficient, epsilon, is calculated in terms of properties of the particle orbit and the results are applied to a calculation of depolarization in the AGS.

  9. Representing Learning With Graphical Models

    NASA Technical Reports Server (NTRS)

    Buntine, Wray L.; Lum, Henry, Jr. (Technical Monitor)

    1994-01-01

    Probabilistic graphical models are being used widely in artificial intelligence, for instance, in diagnosis and expert systems, as a unified qualitative and quantitative framework for representing and reasoning with probabilities and independencies. Their development and use spans several fields including artificial intelligence, decision theory and statistics, and provides an important bridge between these communities. This paper shows by way of example that these models can be extended to machine learning, neural networks and knowledge discovery by representing the notion of a sample on the graphical model. Not only does this allow a flexible variety of learning problems to be represented, it also provides the means for representing the goal of learning and opens the way for the automatic development of learning algorithms from specifications.

  10. Energy efficient data centers

    SciTech Connect

    Tschudi, William; Xu, Tengfang; Sartor, Dale; Koomey, Jon; Nordman, Bruce; Sezgen, Osman

    2004-03-30

    study findings, and participation in data center industry meetings and workshops. Industry partners enthusiastically provided valuable insight into current practice, and helped to identify areas where additional public interest research could lead to significant efficiency improvement. This helped to define and prioritize the research agenda. The interaction involved industry representatives with expertise in all aspects of data center facilities, including specialized facility infrastructure systems and computing equipment. In addition to the input obtained through industry workshops, LBNL's participation in a three-day, comprehensive design ''charrette'' hosted by the Rocky Mountain Institute (RMI) yielded a number of innovative ideas for future research.

  11. ILC Reference Design Report: Accelerator Executive Summary

    SciTech Connect

    Phinney, Nan; /SLAC

    2007-12-14

    a proposal for a 500 GeV center-of-mass linear collider in 2001 [2]. The concurrent (competing) design work on a normal conducting collider (NLC with X-band [3] and GLC with X- or C-Band [4]), has advanced the design concepts for the ILC injectors, Damping Rings (DR) and Beam Delivery System (BDS), as well as addressing overall operations, machine protection and availability issues. The X- and C-band R&D has led to concepts for the RF power source that may eventually produce either cost and/or performance benefits. Finally, the European XFEL [5] to be constructed at DESY, Hamburg, Germany, will make use of the TESLA linac technology, and represents a significant on-going R&D effort which remains of great benefit for the ILC. The current ILC baseline assumes an accelerating gradient of 31.5 MV/m to achieve a centre-of-mass energy of 500 GeV. The high luminosity requires the use of high power and small emittance beams. The choice of 1.3 GHz SCRF is well suited to the requirements, primarily because the very low power loss in the SCRF cavity walls allows the use of long RF pulses, relaxing the requirements on the peak-power generation, and ultimately leading to high wall-plug to beam transfer efficiency. The primary cost drivers are the SCRF Main Linac technology and the Conventional Facilities (including civil engineering). The choice of gradient is a key cost and performance parameter, since it dictates the length of the linacs, while the cavity quality factor (Q{sub 0}) relates to the required cryogenic cooling power. The achievement of 31.5 MV/m as the baseline average operational accelerating gradient--requiring a minimum performance of 35 MV/m during cavity mass-production acceptance testing--represents the primary challenge to the global ILC R&D With the completion of the RDR, the GDE will shortly begin an engineering design study, closely coupled with a prioritized R&D program. The goal is to produce an Engineering Design Report (EDR) demonstrating readiness

  12. Scaling FFAG accelerator for muon acceleration

    SciTech Connect

    Lagrange, JB.; Planche, T.; Mori, Y.

    2011-10-06

    Recent developments in scaling fixed field alternating gradient (FFAG) accelerators have opened new ways for lattice design, with straight sections, and insertions like dispersion suppressors. Such principles and matching issues are detailed in this paper. An application of these new concepts is presented to overcome problems in the PRISM project.

  13. Scaling FFAG accelerator for muon acceleration

    NASA Astrophysics Data System (ADS)

    Lagrange, JB.; Planche, T.; Mori, Y.

    2011-10-01

    Recent developments in scaling fixed field alternating gradient (FFAG) accelerators have opened new ways for lattice design, with straight sections, and insertions like dispersion suppressors. Such principles and matching issues are detailed in this paper. An application of these new concepts is presented to overcome problems in the PRISM project.

  14. Angular velocities, angular accelerations, and coriolis accelerations

    NASA Technical Reports Server (NTRS)

    Graybiel, A.

    1975-01-01

    Weightlessness, rotating environment, and mathematical analysis of Coriolis acceleration is described for man's biological effective force environments. Effects on the vestibular system are summarized, including the end organs, functional neurology, and input-output relations. Ground-based studies in preparation for space missions are examined, including functional tests, provocative tests, adaptive capacity tests, simulation studies, and antimotion sickness.

  15. A Concept for Directly Coupled Pulsed Electromagnetic Acceleration of Plasmas

    NASA Technical Reports Server (NTRS)

    Thio, Y.C. Francis; Cassibry, Jason T.; Eskridge, Richard; Smith, James; Wu, S. T.; Rodgers, Stephen L. (Technical Monitor)

    2001-01-01

    Plasma jets with high momentum flux density are required for a variety of applications in propulsion research. Methods of producing these plasma jets are being investigated at NASA Marshall Space Flight Center. The experimental goal in the immediate future is to develop plasma accelerators which are capable of producing plasma jets with momentum flux density represented by velocities up to 200 km/s and ion density up to 10(exp 24) per cu m, with sufficient precision and reproducibility in their properties, and with sufficiently high efficiency. The jets must be sufficiently focused to allow them to be transported over several meters. A plasma accelerator concept is presented that might be able to meet these requirements. It is a self-switching, shaped coaxial pulsed plasma thruster, with focusing of the plasma flow by shaping muzzle current distribution as in plasma focus devices, and by mechanical tapering of the gun walls. Some 2-D MHD modeling in support of the conceptual design will be presented.

  16. Center for Space Construction

    NASA Technical Reports Server (NTRS)

    Su, Renjeng

    1998-01-01

    The Center for Space Construction (CSC) at University of Colorado at Boulder is one of eight University Space Engineering Research Centers established by NASA in 1988. The mission of the Center is to conduct research into space technology and to directly contribute to space engineering education. The Center reports to the Department of Aerospace Engineering Sciences and resides in the College of Engineering and Applied Sciences. The College has a long and successful track record of cultivating multi-disciplinary research and education programs. The Center for Space Construction represents prominent evidence of this record. The basic concept on which the Center was founded is the in-space construction of large space systems, such as space stations, interplanetary space vehicles, and extraterrestrial space structures. Since 1993, the scope of CSC research has evolved to include the design and construction of all spacecraft, large and small. With the broadened scope our research projects seek to impact the technological basis for spacecraft such as remote sensing satellites, communication satellites and other special-purpose spacecraft, as well as large space platforms. A summary of accomplishments, including student participation and degrees awarded, during the contract period is presented.

  17. Induction linear accelerators

    NASA Astrophysics Data System (ADS)

    Birx, Daniel

    1992-03-01

    Among the family of particle accelerators, the Induction Linear Accelerator is the best suited for the acceleration of high current electron beams. Because the electromagnetic radiation used to accelerate the electron beam is not stored in the cavities but is supplied by transmission lines during the beam pulse it is possible to utilize very low Q (typically<10) structures and very large beam pipes. This combination increases the beam breakup limited maximum currents to of order kiloamperes. The micropulse lengths of these machines are measured in 10's of nanoseconds and duty factors as high as 10-4 have been achieved. Until recently the major problem with these machines has been associated with the pulse power drive. Beam currents of kiloamperes and accelerating potentials of megavolts require peak power drives of gigawatts since no energy is stored in the structure. The marriage of liner accelerator technology and nonlinear magnetic compressors has produced some unique capabilities. It now appears possible to produce electron beams with average currents measured in amperes, peak currents in kiloamperes and gradients exceeding 1 MeV/meter, with power efficiencies approaching 50%. The nonlinear magnetic compression technology has replaced the spark gap drivers used on earlier accelerators with state-of-the-art all-solid-state SCR commutated compression chains. The reliability of these machines is now approaching 1010 shot MTBF. In the following paper we will briefly review the historical development of induction linear accelerators and then discuss the design considerations.

  18. Accelerator Science: Why RF?

    SciTech Connect

    Lincoln, Don

    2016-12-21

    Particle accelerators can fire beams of subatomic particles at near the speed of light. The accelerating force is generated using radio frequency technology and a whole lot of interesting features. In this video, Fermilab’s Dr. Don Lincoln explains how it all works.

  19. Particle Acceleration in Jets

    NASA Technical Reports Server (NTRS)

    Nishikawa, Ken-Ichi

    2005-01-01

    Nonthermal radiation observed from astrophysical systems containing relativistic jets and shocks, e.g., active galactic nuclei (AGNs), gamma ray burst (GRBs), and Galactic microquasar systems usually have power-law emission spectra. Fermi acceleration is the mechanism usually assumed for the acceleration of particles in astrophysical environments.

  20. Accelerators Beyond The Tevatron?

    SciTech Connect

    Lach, Joseph; /Fermilab

    2010-07-01

    Following the successful operation of the Fermilab superconducting accelerator three new higher energy accelerators were planned. They were the UNK in the Soviet Union, the LHC in Europe, and the SSC in the United States. All were expected to start producing physics about 1995. They did not. Why?

  1. Accelerators (3/5)

    ScienceCinema

    None

    2016-07-12

    1a) Introduction and motivation 1b) History and accelerator types 2) Transverse beam dynamics 3a) Longitudinal beam dynamics 3b) Figure of merit of a synchrotron/collider 3c) Beam control 4) Main limiting factors 5) Technical challenges Prerequisite knowledge: Previous knowledge of accelerators is not required.

  2. Diagnostics for induction accelerators

    SciTech Connect

    Fessenden, T.J.

    1996-04-01

    The induction accelerator was conceived by N. C. Christofilos and first realized as the Astron accelerator that operated at LLNL from the early 1960`s to the end of 1975. This accelerator generated electron beams at energies near 6 MeV with typical currents of 600 Amperes in 400 ns pulses. The Advanced Test Accelerator (ATA) built at Livermore`s Site 300 produced 10,000 Ampere beams with pulse widths of 70 ns at energies approaching 50 MeV. Several other electron and ion induction accelerators have been fabricated at LLNL and LBNL. This paper reviews the principal diagnostics developed through efforts by scientists at both laboratories for measuring the current, position, energy, and emittance of beams generated by these high current, short pulse accelerators. Many of these diagnostics are closely related to those developed for other accelerators. However, the very fast and intense current pulses often require special diagnostic techniques and considerations. The physics and design of the more unique diagnostics developed for electron induction accelerators are presented and discussed in detail.

  3. Accelerators (4/5)

    ScienceCinema

    None

    2016-07-12

    1a) Introduction and motivation 1b) History and accelerator types 2) Transverse beam dynamics 3a) Longitudinal beam dynamics 3b) Figure of merit of a synchrotron/collider 3c) Beam control 4) Main limiting factors 5) Technical challenges Prerequisite knowledge: Previous knowledge of accelerators is not required.

  4. Measuring Model Rocket Acceleration.

    ERIC Educational Resources Information Center

    Jenkins, Randy A.

    1993-01-01

    Presents an experiment that measures the acceleration and velocity of a model rocket. Lift-off information is transmitted to a computer that creates a graph of the velocity. Discusses the analysis of the computer-generated data and differences between calculated and experimental velocity and acceleration of several rocket types. (MDH)

  5. Microscale acceleration history discriminators

    DOEpatents

    Polosky, Marc A.; Plummer, David W.

    2002-01-01

    A new class of micromechanical acceleration history discriminators is claimed. These discriminators allow the precise differentiation of a wide range of acceleration-time histories, thereby allowing adaptive events to be triggered in response to the severity (or lack thereof) of an external environment. Such devices have applications in airbag activation, and other safety and surety applications.

  6. Accelerators (5/5)

    ScienceCinema

    None

    2016-07-12

    1a) Introduction and motivation 1b) History and accelerator types 2) Transverse beam dynamics 3a) Longitudinal beam dynamics 3b) Figure of merit of a synchrotron/collider 3c) Beam control 4) Main limiting factors 5) Technical challenges Prerequisite knowledge: Previous knowledge of accelerators is not required.

  7. Accelerators Beyond The Tevatron?

    SciTech Connect

    Lach, Joseph

    2010-07-29

    Following the successful operation of the Fermilab superconducting accelerator three new higher energy accelerators were planned. They were the UNK in the Soviet Union, the LHC in Europe, and the SSC in the United States. All were expected to start producing physics about 1995. They did not. Why?.

  8. Accelerators, Beams And Physical Review Special Topics - Accelerators And Beams

    SciTech Connect

    Siemann, R.H.; /SLAC

    2011-10-24

    Accelerator science and technology have evolved as accelerators became larger and important to a broad range of science. Physical Review Special Topics - Accelerators and Beams was established to serve the accelerator community as a timely, widely circulated, international journal covering the full breadth of accelerators and beams. The history of the journal and the innovations associated with it are reviewed.

  9. Center for Healthcare Technologies

    SciTech Connect

    Carrano, A.V.

    1994-03-01

    In the U.S., we now spend about 13% of the gross domestic product (CDP) on healthcare. This figure represents nearly $3000 per year per man, woman, and child. Moreover, this expenditure is projected to grow to about 20% of the GDP by the year 2000. Medical research and development accounts for only about 3% of national healthcare spending, and technology development represents only a small fraction of that 3%. New technologies that are far more cost-effective than previous ones - such as minimally invasive surgical procedures, advanced automated diagnostics, and better information systems - could save the nation billions of dollars per year to say nothing of the potential reductions in pain and suffering. A center is described that will coordinate ongoing Laboratory research aimed at developing more cost-effective tools for use by the healthcare community. The new Center for Healthcare Technologies will have many long-term benefits for the region and the nation.

  10. The Future of Accelerator Physics. The Tamura Symposium Proceedings

    SciTech Connect

    Tajima, T.

    1996-04-01

    These proceedings represent the papers presented at the Tamura symposium on accelerator physics. The topics discussed include many novel ideas for future exploration, for example, 30TeV X 30TeV collider, Moebius accelerator, new magnets, new table{minus}top terawatt (T3) lasers, free space accelerators, advanced cooling of beams, including optical cooling,etc.. There were 30 papers presented at the symposium and 28 have been abstracted for the Energy Science and Technology database.(AIP)

  11. Rail accelerators for space transportation: An experimental investigation

    NASA Technical Reports Server (NTRS)

    Zana, L. M.; Kerslake, W. R.; Sturman, J. L.

    1986-01-01

    An experimental program was conducted at the Lewis Research Center with the objective of investigating the technical feasibility of rail accelerators for propulsion applications. Single-stage, plasma driven rail accelerators of small (4 by 6 mm) and medium (12.5 by 12.5 mm) bores were tested at peak accelerating currents of 50 to 450 kA. Streak-camera photography was used to provide a qualitative description of plasma armature acceleration. The effects of plasma blowby and varying bore pressure on the behavior of plasma armatures were studied.

  12. Accelerating the commercialization of university technologies for military healthcare applications: the role of the proof of concept process

    NASA Astrophysics Data System (ADS)

    Ochoa, Rosibel; DeLong, Hal; Kenyon, Jessica; Wilson, Eli

    2011-06-01

    The von Liebig Center for Entrepreneurism and Technology Advancement at UC San Diego (vonliebig.ucsd.edu) is focused on accelerating technology transfer and commercialization through programs and education on entrepreneurism. Technology Acceleration Projects (TAPs) that offer pre-venture grants and extensive mentoring on technology commercialization are a key component of its model which has been developed over the past ten years with the support of a grant from the von Liebig Foundation. In 2010, the von Liebig Entrepreneurism Center partnered with the U.S. Army Telemedicine and Advanced Technology Research Center (TATRC), to develop a regional model of Technology Acceleration Program initially focused on military research to be deployed across the nation to increase awareness of military medical needs and to accelerate the commercialization of novel technologies to treat the patient. Participants to these challenges are multi-disciplinary teams of graduate students and faculty in engineering, medicine and business representing universities and research institutes in a region, selected via a competitive process, who receive commercialization assistance and funding grants to support translation of their research discoveries into products or services. To validate this model, a pilot program focused on commercialization of wireless healthcare technologies targeting campuses in Southern California has been conducted with the additional support of Qualcomm, Inc. Three projects representing three different universities in Southern California were selected out of forty five applications from ten different universities and research institutes. Over the next twelve months, these teams will conduct proof of concept studies, technology development and preliminary market research to determine the commercial feasibility of their technologies. This first regional program will help build the needed tools and processes to adapt and replicate this model across other regions in the

  13. Representing and Acquiring Geographic Knowledge.

    DTIC Science & Technology

    1984-01-01

    Management, Inc. 5 copies 1300 Wilson Boulevard, Suite 102 Arlington, Virginia 22209 Ms. Robin Dillard 1 copy Naval Ocean System Center C2 Information...the road. Conceivably, it could curl round and come closer to *the pond at some other point. We mus,. therefore ask for the minimal distance between...both of th’se. There is no general scheme for resolving these interactions. Rather, we must simply decide priorities , and force the lower priority

  14. Principal Investigator Microgravity Services Role in ISS Acceleration Data Distribution

    NASA Technical Reports Server (NTRS)

    McPherson, Kevin

    1999-01-01

    Measurement of the microgravity acceleration environment on the International Space Station will be accomplished by two accelerometer systems. The Microgravity Acceleration Measurement System will record the quasi-steady microgravity environment, including the influences of aerodynamic drag, vehicle rotation, and venting effects. Measurement of the vibratory/transient regime comprised of vehicle, crew, and equipment disturbances will be accomplished by the Space Acceleration Measurement System-II. Due to the dynamic nature of the microgravity environment and its potential to influence sensitive experiments, Principal Investigators require distribution of microgravity acceleration in a timely and straightforward fashion. In addition to this timely distribution of the data, long term access to International Space Station microgravity environment acceleration data is required. The NASA Glenn Research Center's Principal Investigator Microgravity Services project will provide the means for real-time and post experiment distribution of microgravity acceleration data to microgravity science Principal Investigators. Real-time distribution of microgravity environment acceleration data will be accomplished via the World Wide Web. Data packets from the Microgravity Acceleration Measurement System and the Space Acceleration Measurement System-II will be routed from onboard the International Space Station to the NASA Glenn Research Center's Telescience Support Center. Principal Investigator Microgravity Services' ground support equipment located at the Telescience Support Center will be capable of generating a standard suite of acceleration data displays, including various time domain and frequency domain options. These data displays will be updated in real-time and will periodically update images available via the Principal Investigator Microgravity Services web page.

  15. Large electrostatic accelerators

    SciTech Connect

    Jones, C.M.

    1984-01-01

    The increasing importance of energetic heavy ion beams in the study of atomic physics, nuclear physics, and materials science has partially or wholly motivated the construction of a new generation of large electrostatic accelerators designed to operate at terminal potentials of 20 MV or above. In this paper, the author briefly discusses the status of these new accelerators and also discusses several recent technological advances which may be expected to further improve their performance. The paper is divided into four parts: (1) a discussion of the motivation for the construction of large electrostatic accelerators, (2) a description and discussion of several large electrostatic accelerators which have been recently completed or are under construction, (3) a description of several recent innovations which may be expected to improve the performance of large electrostatic accelerators in the future, and (4) a description of an innovative new large electrostatic accelerator whose construction is scheduled to begin next year. Due to time and space constraints, discussion is restricted to consideration of only tandem accelerators.

  16. Representing and acquiring geographic knowledge

    SciTech Connect

    Davis, E.

    1986-01-01

    Intended for researchers and students in AI, cognitive psychology, and computational geometry, this work presents an original theory of how knowledge of a large-scale neighborhood can be represented symbolically in a computer program, accessed for use, and increased by experience. The discussion analyzes related work in the field, presents an actual computer implementation, and suggests areas for further research.

  17. Representing and acquiring geographic knowledge

    SciTech Connect

    Davis, E.

    1986-01-01

    This book presents a theory of how knowledge of a large-scale neighborhood can be represented symbolically in a computer program, accessed for use, and increased by experience. The discussion analyzes related work in the field, presents an actual computer implementation, and suggests areas for further research.

  18. Hastings Center

    MedlinePlus

    ... on, and advocacy for, wiser health care and science policy. In addition to her leadership role at The Hastings Center, she is a professor at Harvard Medical School, where she directs the school’s Fellowship in Bioethics, a program that ...

  19. Vacuum Beat Wave Accelerator

    NASA Astrophysics Data System (ADS)

    Moore, C. I.; Hafizi, B.; Ting, A.; Burris, H. R.; Sprangle, P.; Esarey, E.; Ganguly, A.; Hirshfield, J. L.

    1997-11-01

    The Vacuum Beat Wave Accelerator (VBWA) is a particle acceleration scheme which uses the non-linear ponderomotive beating of two different frequency laser beams to accelerate electrons. A proof-of-principle experiment to demonstrate the VBWA is underway at the Naval Research Laboratory (NRL). This experiment will use the beating of a 1054 nm and 527 nm laser pulse from the NRL T-cubed laser to generate the beat wave and a 4.5 MeV RF electron gun as the electron source. Simulation results and the experimental design will be presented. The suitability of using axicon or higher order Gaussian laser beams will also be discussed.

  20. Ion beam accelerator system

    NASA Technical Reports Server (NTRS)

    Aston, Graeme (Inventor)

    1984-01-01

    A system is described that combines geometrical and electrostatic focusing to provide high ion extraction efficiency and good focusing of an accelerated ion beam. The apparatus includes a pair of curved extraction grids (16, 18) with multiple pairs of aligned holes positioned to direct a group of beamlets (20) along converging paths. The extraction grids are closely spaced and maintained at a moderate potential to efficiently extract beamlets of ions and allow them to combine into a single beam (14). An accelerator electrode device (22) downstream from the extraction grids, is at a much lower potential than the grids to accelerate the combined beam.

  1. Ion beam accelerator system

    NASA Technical Reports Server (NTRS)

    Aston, G. (Inventor)

    1981-01-01

    A system is described that combines geometrical and electrostatic focusing to provide high ion extraction efficiency and good focusing of an accelerated ion beam. The apparatus includes a pair of curved extraction grids with multiple pairs of aligned holes positioned to direct a group of beamlets along converging paths. The extraction grids are closely spaced and maintained at a moderate potential to efficiently extract beamlets of ions and allow them to combine into a single beam. An accelerator electrode device downstream from the extraction grids is at a much lower potential than the grids to accelerate the combined beam. The application of the system to ion implantation is mentioned.

  2. Centrifuge Study of Pilot Tolerance to Acceleration and the Effects of Acceleration on Pilot Performance

    NASA Technical Reports Server (NTRS)

    Creer, Brent Y.; Smedal, Harald A.; Wingrove, Rodney C.

    1960-01-01

    A research program the general objective of which was to measure the effects of various sustained accelerations on the control performance of pilots, was carried out on the Aviation Medical Acceleration Laboratory centrifuge, U.S. Naval Air Development Center, Johnsville, PA. The experimental setup consisted of a flight simulator with the centrifuge in the control loop. The pilot performed his control tasks while being subjected to acceleration fields such as might be encountered by a forward-facing pilot flying an atmosphere entry vehicle. The study was divided into three phases. In one phase of the program, the pilots were subjected to a variety of sustained linear acceleration forces while controlling vehicles with several different sets of longitudinal dynamics. Here, a randomly moving target was displayed to the pilot on a cathode-ray tube. For each combination of acceleration field and vehicle dynamics, pilot tracking accuracy was measured and pilot opinion of the stability and control characteristics was recorded. Thus, information was obtained on the combined effects of complexity of control task and magnitude and direction of acceleration forces on pilot performance. These tests showed that the pilot's tracking performance deteriorated markedly at accelerations greater than about 4g when controlling a lightly damped vehicle. The tentative conclusion was also reached that regardless of the airframe dynamics involved, the pilot feels that in order to have the same level of control over the vehicle, an increase in the vehicle dynamic stability was required with increases in the magnitudes of the acceleration impressed upon the pilot. In another phase, boundaries of human tolerance of acceleration were established for acceleration fields such as might be encountered by a pilot flying an orbital vehicle. A special pilot restraint system was developed to increase human tolerance to longitudinal decelerations. The results of the tests showed that human tolerance

  3. The Fermilab Particle Astrophysics Center

    SciTech Connect

    Not Available

    2004-11-01

    The Particle Astrophysics Center was established in fall of 2004. Fermilab director Michael S. Witherell has named Fermilab cosmologist Edward ''Rocky'' Kolb as its first director. The Center will function as an intellectual focus for particle astrophysics at Fermilab, bringing together the Theoretical and Experimental Astrophysics Groups. It also encompasses existing astrophysics projects, including the Sloan Digital Sky Survey, the Cryogenic Dark Matter Search, and the Pierre Auger Cosmic Ray Observatory, as well as proposed projects, including the SuperNova Acceleration Probe to study dark energy as part of the Joint Dark Energy Mission, and the ground-based Dark Energy Survey aimed at measuring the dark energy equation of state.

  4. Computational Meso-Scale Study of Representative Unit Cubes for Inert Spheres Subject to Intense Shocks

    NASA Astrophysics Data System (ADS)

    Stewart, Cameron; Najjar, Fady; Stewart, D. Scott; Bdzil, John

    2012-11-01

    Modern-engineered high explosive (HE) materials can consist of a matrix of solid, inert particles embedded into an HE charge. When this charge is detonated, intense shock waves are generated. As these intense shocks interact with the inert particles, large deformations occur in the particles while the incident shock diffracts around the particle interface. We will present results from a series of 3-D DNS of an intense shock interacting with unit-cube configurations of inert particles embedded into nitromethane. The LLNL multi-physics massively parallel hydrodynamics code ALE3D is used to carry out high-resolution (4 million nodes) simulations. Three representative unit-cube configurations are considered: primitive cubic, face-centered and body-centered cubic for two particle material types of varying impedance ratios. Previous work has only looked at in-line particles configurations. We investigate the time evolution of the unit cell configurations, vorticity being generated by the shock interaction, as well as the velocity and acceleration of the particles until they reach the quasi-steady regime. LLNL-ABS-567694. CSS was supported by a summer internship through the HEDP program at LLNL. FMN's work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  5. A New Control Room for SLAC Accelerators

    SciTech Connect

    Erickson, Roger; Guerra, E.; Stanek, M.; Hoover, Z.Van; Warren, J.; /SLAC

    2012-06-04

    We are planning to construct a new control room at SLAC to unify and improve the operation of the LCLS, SPEAR3, and FACET accelerator facilities, and to provide the space and flexibility needed to support the LCLS-II and proposed new test beam facilities. The existing control rooms for the linac and SPEAR3 have been upgraded in various ways over the last decade, but their basic features have remained unchanged. We propose to build a larger modern Accelerator Control Room (ACR) in the new Research Support Building (RSB) which is currently under construction at SLAC. Shifting the center of control for the accelerator facilities entails both technical and administrative challenges. In this paper, we describe the history, concept, and status of this project.

  6. Trends in accelerator technology for hadron therapy

    NASA Astrophysics Data System (ADS)

    Kostromin, S. A.; Syresin, E. M.

    2013-12-01

    Hadron therapy with protons and carbon ions is one of the most effective branches in radiation oncology. It has advantages over therapy using gamma radiation and electron beams. Fifty thousand patients a year need such treatment in Russia. A review of the main modern trends in the development of accelerators for therapy and treatment techniques concerned with respiratory gated irradiation and scanning with the intensity modulated pencil beams is given. The main stages of formation, time structure, and the main parameters of the beams used in proton therapy, as well as the requirements for medicine accelerators, are considered. The main results of testing with the beam of the C235-V3 cyclotron for the first Russian specialized hospital proton therapy center in Dimitrovgrad are presented. The use of superconducting accelerators and gantry systems for hadron therapy is considered.

  7. Gas Filled Coaxial Accelerator with Compression Coil

    NASA Technical Reports Server (NTRS)

    Espy, Patrick N. (Inventor)

    1976-01-01

    A self-energized plasma compressor which compresses plasma discharged from a coaxial plasma generator. The device includes a helical shaped coil which is coaxially aligned with the center axis of the coaxial plasma generator. The plasma generator creates a current through the helical coil which, in turn, generates a time varying magnetic field that generates a force which acts radially upon the plasma. A seal is carried on the end of the coaxial plasma generator for containing gas therein. As the plasma is accelerated out the outer end of the generator, it forces the gas outwardly also compressing such. Beads are carried adjacent the small end of the helical shaped coil for being accelerated to hypervelocities by the plasma and gas. As a result of utilizing gas in the coaxial plasma generator, such minimizes ablation of the beads as well as accelerates such to higher velocities.

  8. Proceedings of: 2005 Particle Acceleration Confence

    SciTech Connect

    Henderson, Stuart

    2006-01-01

    The 21st Particle Accelerator Conference, PAC05, took place at the Knoxville Convention Center (KCC) from Monday through Friday, May 16-20, 2005. Sponsored by the American Physical Society (APS), the Institute of Electrics and Electronics Engineers (IEEE) with its subdivision of Nuclear and Plasma Sciences Society (NPSS), the conference was hosted by the Oak Ridge National Laboratory (ORNL) Spallation Neutron Source (SNS) Project and Thomas Jefferson National Accelerator Facility (JLab). The conference was chaired by Norbert Holtkamp, and the Local Organizing Committee was made up of staff from the ORNL SNS Project under the chairmanship of Stuart Henderson. The conference welcomed over 1400 delegates from the United States, Europe, Asia, the Middle East, South America and from as far away as Australia. Almost 1400 papers where processed during the conference and will be published on the Joint Accelerator Conferences Website (JACoW) page.

  9. NCI Technology Transfer Center | TTC

    Cancer.gov

    The National Cancer Institute’s Technology Transfer Center (TTC) facilitates partnerships between the NIH research laboratories and external partners. With specialized teams, TTC guides the interactions of our partners from the point of discovery to patenting, from invention development to licensing. We play a key role in helping to accelerate development of cutting-edge research by connecting our partners to NIH’s world-class researchers, facilities, and knowledge.

  10. The Learning Technology Center at Vanderbilt University.

    ERIC Educational Resources Information Center

    Bransford, John

    1994-01-01

    Describes the Vanderbilt University (Tennessee) Learning Technology Center, including profile of the center's personnel; description of representative projects, such as the Jasper-Woodbury Problem Solving Series, a multimedia literacy program for grades K-3, and the Adult Literacy Program; and a list of 14 representative publications by center…

  11. CLASHING BEAM PARTICLE ACCELERATOR

    DOEpatents

    Burleigh, R.J.

    1961-04-11

    A charged-particle accelerator of the proton synchrotron class having means for simultaneously accelerating two separate contra-rotating particle beams within a single annular magnet structure is reported. The magnet provides two concentric circular field regions of opposite magnetic polarity with one field region being of slightly less diameter than the other. The accelerator includes a deflector means straddling the two particle orbits and acting to collide the two particle beams after each has been accelerated to a desired energy. The deflector has the further property of returning particles which do not undergo collision to the regular orbits whereby the particles recirculate with the possibility of colliding upon subsequent passages through the deflector.

  12. Vibration control in accelerators

    SciTech Connect

    Montag, C.

    2011-01-01

    In the vast majority of accelerator applications, ground vibration amplitudes are well below tolerable magnet jitter amplitudes. In these cases, it is necessary and sufficient to design a rigid magnet support structure that does not amplify ground vibration. Since accelerator beam lines are typically installed at an elevation of 1-2m above ground level, special care has to be taken in order to avoid designing a support structure that acts like an inverted pendulum with a low resonance frequency, resulting in untolerable lateral vibration amplitudes of the accelerator components when excited by either ambient ground motion or vibration sources within the accelerator itself, such as cooling water pumps or helium flow in superconducting magnets. In cases where ground motion amplitudes already exceed the required jiter tolerances, for instance in future linear colliders, passive vibration damping or active stabilization may be considered.

  13. Dielectric assist accelerating structure

    NASA Astrophysics Data System (ADS)

    Satoh, D.; Yoshida, M.; Hayashizaki, N.

    2016-01-01

    A higher-order TM02 n mode accelerating structure is proposed based on a novel concept of dielectric loaded rf cavities. This accelerating structure consists of ultralow-loss dielectric cylinders and disks with irises which are periodically arranged in a metallic enclosure. Unlike conventional dielectric loaded accelerating structures, most of the rf power is stored in the vacuum space near the beam axis, leading to a significant reduction of the wall loss, much lower than that of conventional normal-conducting linac structures. This allows us to realize an extremely high quality factor and a very high shunt impedance at room temperature. A simulation of a 5 cell prototype design with an existing alumina ceramic indicates an unloaded quality factor of the accelerating mode over 120 000 and a shunt impedance exceeding 650 M Ω /m at room temperature.

  14. Wake field acceleration experiments

    SciTech Connect

    Simpson, J.D.

    1988-01-01

    Where and how will wake field acceleration devices find use for other than, possibly, accelerators for high energy physics. I don't know that this can be responsibly answered at this time. What I can do is describe some recent results from an ongoing experimental program at Argonne which support the idea that wake field techniques and devices are potentially important for future accelerators. Perhaps this will spawn expanded interest and even new ideas for the use of this new technology. The Argonne program, and in particular the Advanced Accelerator Test Facility (AATF), has been reported in several fairly recent papers and reports. But because this is a substantially new audience for the subject, I will include a brief review of the program and the facility before describing experiments. 10 refs., 7 figs.

  15. Accelerator on a Chip

    SciTech Connect

    England, Joel

    2014-06-30

    SLAC's Joel England explains how the same fabrication techniques used for silicon computer microchips allowed their team to create the new laser-driven particle accelerator chips. (SLAC Multimedia Communications)

  16. Charged particle accelerator grating

    DOEpatents

    Palmer, R.B.

    1985-09-09

    A readily disposable and replaceable accelerator grating for a relativistic particle accelerator is described. The grating is formed for a plurality of liquid droplets that are directed in precisely positioned jet streams to periodically dispose rows of droplets along the borders of a predetermined particle beam path. A plurality of lasers are used to direct laser beams onto the droplets, at predetermined angles, thereby to excite the droplets to support electromagnetic accelerating resonances on their surfaces. Those resonances operate to accelerate and focus particles moving along the beam path. As the droplets are distorted or destroyed by the incoming radiation, they are replaced at a predetermined frequency by other droplets supplied through the jet streams.

  17. HEAVY ION LINEAR ACCELERATOR

    DOEpatents

    Van Atta, C.M.; Beringer, R.; Smith, L.

    1959-01-01

    A linear accelerator of heavy ions is described. The basic contributions of the invention consist of a method and apparatus for obtaining high energy particles of an element with an increased charge-to-mass ratio. The method comprises the steps of ionizing the atoms of an element, accelerating the resultant ions to an energy substantially equal to one Mev per nucleon, stripping orbital electrons from the accelerated ions by passing the ions through a curtain of elemental vapor disposed transversely of the path of the ions to provide a second charge-to-mass ratio, and finally accelerating the resultant stripped ions to a final energy of at least ten Mev per nucleon.

  18. Principles of Induction Accelerators

    NASA Astrophysics Data System (ADS)

    Briggs*, Richard J.

    The basic concepts involved in induction accelerators are introduced in this chapter. The objective is to provide a foundation for the more detailed coverage of key technology elements and specific applications in the following chapters. A wide variety of induction accelerators are discussed in the following chapters, from the high current linear electron accelerator configurations that have been the main focus of the original developments, to circular configurations like the ion synchrotrons that are the subject of more recent research. The main focus in the present chapter is on the induction module containing the magnetic core that plays the role of a transformer in coupling the pulsed power from the modulator to the charged particle beam. This is the essential common element in all these induction accelerators, and an understanding of the basic processes involved in its operation is the main objective of this chapter. (See [1] for a useful and complementary presentation of the basic principles in induction linacs.)

  19. Accelerator on a Chip

    ScienceCinema

    England, Joel

    2016-07-12

    SLAC's Joel England explains how the same fabrication techniques used for silicon computer microchips allowed their team to create the new laser-driven particle accelerator chips. (SLAC Multimedia Communications)

  20. DIELECTRIC WALL ACCELERATOR TECHNOLOGY

    SciTech Connect

    Sampayan, S; Caporaso, G; Chen, Y; Harris, J; Hawkins, S; Holmes, C; Nelson, S; Poole, B; Rhodes, M; Sanders, D; Sullivan, J; Wang, L; Watson, J

    2007-10-18

    The dielectric wall accelerator (DWA) is a compact pulsed power device where the pulse forming lines, switching, and vacuum wall are integrated into a single compact geometry. For this effort, we initiated a extensive compact pulsed power development program and have pursued the study of switching (gas, oil, laser induced surface flashover and photoconductive), dielectrics (ceramics and nanoparticle composites), pulse forming line topologies (asymmetric and symmetric Blumleins and zero integral pulse forming lines), and multilayered vacuum insulator (HGI) technology. Finally, we fabricated an accelerator cell for test on ETAII (a 5.5 MeV, 2 kA, 70 ns pulsewidth electron beam accelerator). We review our past results and report on the progress of accelerator cell testing.

  1. Flight representative positive isolation disconnect

    NASA Technical Reports Server (NTRS)

    Rosener, A. A.; Jonkoniec, T. G.

    1977-01-01

    Resolutions were developed for each problem encountered and a tradeoff analysis was performed to select a final configuration for a flight representative PID (Positive Isolation Disconnect) that is reduced in size and comparable in weight and pressure drop to the developmental PID. A 6.35 mm (1/4-inch) line size PID was fabricated and tested. The flight representative PID consists of two coupled disconnect halves, each capable of fluid isolation with essentially zero clearance between them for zero leakage upon disconnect half disengagement. An interlocking foolproofing technique prevents uncoupling of disconnect halves prior to fluid isolation. Future development efforts for the Space Shuttle subsystems that would benefit from the use of the positive isolation disconnect are also recommended. Customary units were utilized for principal measurements and calculations with conversion factors being inserted in equations to convert the results to the international system of units.

  2. Representing videos in tangible products

    NASA Astrophysics Data System (ADS)

    Fageth, Reiner; Weiting, Ralf

    2014-03-01

    Videos can be taken with nearly every camera, digital point and shoot cameras, DSLRs as well as smartphones and more and more with so-called action cameras mounted on sports devices. The implementation of videos while generating QR codes and relevant pictures out of the video stream via a software implementation was contents in last years' paper. This year we present first data about what contents is displayed and how the users represent their videos in printed products, e.g. CEWE PHOTOBOOKS and greeting cards. We report the share of the different video formats used, the number of images extracted out of the video in order to represent the video, the positions in the book and different design strategies compared to regular books.

  3. High-efficiency acceleration of an electron beam in a plasma wakefield accelerator.

    PubMed

    Litos, M; Adli, E; An, W; Clarke, C I; Clayton, C E; Corde, S; Delahaye, J P; England, R J; Fisher, A S; Frederico, J; Gessner, S; Green, S Z; Hogan, M J; Joshi, C; Lu, W; Marsh, K A; Mori, W B; Muggli, P; Vafaei-Najafabadi, N; Walz, D; White, G; Wu, Z; Yakimenko, V; Yocky, G

    2014-11-06

    High-efficiency acceleration of charged particle beams at high gradients of energy gain per unit length is necessary to achieve an affordable and compact high-energy collider. The plasma wakefield accelerator is one concept being developed for this purpose. In plasma wakefield acceleration, a charge-density wake with high accelerating fields is driven by the passage of an ultra-relativistic bunch of charged particles (the drive bunch) through a plasma. If a second bunch of relativistic electrons (the trailing bunch) with sufficient charge follows in the wake of the drive bunch at an appropriate distance, it can be efficiently accelerated to high energy. Previous experiments using just a single 42-gigaelectronvolt drive bunch have accelerated electrons with a continuous energy spectrum and a maximum energy of up to 85 gigaelectronvolts from the tail of the same bunch in less than a metre of plasma. However, the total charge of these accelerated electrons was insufficient to extract a substantial amount of energy from the wake. Here we report high-efficiency acceleration of a discrete trailing bunch of electrons that contains sufficient charge to extract a substantial amount of energy from the high-gradient, nonlinear plasma wakefield accelerator. Specifically, we show the acceleration of about 74 picocoulombs of charge contained in the core of the trailing bunch in an accelerating gradient of about 4.4 gigavolts per metre. These core particles gain about 1.6 gigaelectronvolts of energy per particle, with a final energy spread as low as 0.7 per cent (2.0 per cent on average), and an energy-transfer efficiency from the wake to the bunch that can exceed 30 per cent (17.7 per cent on average). This acceleration of a distinct bunch of electrons containing a substantial charge and having a small energy spread with both a high accelerating gradient and a high energy-transfer efficiency represents a milestone in the development of plasma wakefield acceleration into a

  4. Representative shuttle evaporative heat sink

    NASA Technical Reports Server (NTRS)

    Hixon, C. W.

    1978-01-01

    The design, fabrication, and testing of a representative shuttle evaporative heat sink (RSEHS) system which vaporizes an expendable fluid to provide cooling for the shuttle heat transport fluid loop is reported. The optimized RSEHS minimum weight design meets or exceeds the shuttle flash evaporator system requirements. A cold trap which cryo-pumps flash evaporator exhaust water from the CSD vacuum chamber test facility to prevent water contamination of the chamber pumping equipment is also described.

  5. Amps particle accelerator definition study

    NASA Technical Reports Server (NTRS)

    Sellen, J. M., Jr.

    1975-01-01

    The Particle Accelerator System of the AMPS (Atmospheric, Magnetospheric, and Plasmas in Space) payload is a series of charged particle accelerators to be flown with the Space Transportation System Shuttle on Spacelab missions. In the configuration presented, the total particle accelerator system consists of an energetic electron beam, an energetic ion accelerator, and both low voltage and high voltage plasma acceleration devices. The Orbiter is illustrated with such a particle accelerator system.

  6. Designing reliability into accelerators

    NASA Astrophysics Data System (ADS)

    Hutton, A.

    1992-07-01

    Future accelerators will have to provide a high degree of reliability. Quality must be designed in right from the beginning and must remain a central theme throughout the project. The problem is similar to the problems facing US industry today, and examples of the successful application of quality engineering will be given. Different aspects of an accelerator project will be addressed: Concept, Design, Motivation, Management Techniques, and Fault Diagnosis. The importance of creating and maintaining a coherent team will be stressed.

  7. Microgravity Acceleration Measurement System

    NASA Technical Reports Server (NTRS)

    Foster, William

    2009-01-01

    Microgravity Acceleration Measurement System (MAMS) is an ongoing study of the small forces (vibrations and accelerations) on the ISS that result from the operation of hardware, crew activities, as well as dockings and maneuvering. Results will be used to generalize the types of vibrations affecting vibration-sensitive experiments. Investigators seek to better understand the vibration environment on the space station to enable future research.

  8. CEBAF Accelerator Achievements

    NASA Astrophysics Data System (ADS)

    Chao, Y. C.; Drury, M.; Hovater, C.; Hutton, A.; Krafft, G. A.; Poelker, M.; Reece, C.; Tiefenback, M.

    2011-05-01

    In the past decade, nuclear physics users of Jefferson Lab's Continuous Electron Beam Accelerator Facility (CEBAF) have benefited from accelerator physics advances and machine improvements. As of early 2011, CEBAF operates routinely at 6 GeV, with a 12 GeV upgrade underway. This article reports highlights of CEBAF's scientific and technological evolution in the areas of cryomodule refurbishment, RF control, polarized source development, beam transport for parity experiments, magnets and hysteresis handling, beam breakup, and helium refrigerator operational optimization.

  9. Breakthrough: Fermilab Accelerator Technology

    ScienceCinema

    None

    2016-07-12

    There are more than 30,000 particle accelerators in operation around the world. At Fermilab, scientists are collaborating with other laboratories and industry to optimize the manufacturing processes for a new type of powerful accelerator that uses superconducting niobium cavities. Experimenting with unique polishing materials, a Fermilab team has now developed an efficient and environmentally friendly way of creating cavities that can propel particles with more than 30 million volts per meter.

  10. Rolamite acceleration sensor

    DOEpatents

    Abbin, Joseph P.; Briner, Clifton F.; Martin, Samuel B.

    1993-01-01

    A rolamite acceleration sensor which has a failsafe feature including a housing, a pair of rollers, a tension band wrapped in an S shaped fashion around the rollers, wherein the band has a force-generation cut out and a failsafe cut out or weak portion. The failsafe cut out or weak portion breaks when the sensor is subjected to an excessive acceleration so that the sensor fails in an open circuit (non-conducting) state permanently.

  11. Rolamite acceleration sensor

    DOEpatents

    Abbin, J.P.; Briner, C.F.; Martin, S.B.

    1993-12-21

    A rolamite acceleration sensor is described which has a failsafe feature including a housing, a pair of rollers, a tension band wrapped in an S shaped fashion around the rollers, wherein the band has a force-generation cut out and a failsafe cut out or weak portion. The failsafe cut out or weak portion breaks when the sensor is subjected to an excessive acceleration so that the sensor fails in an open circuit (non-conducting) state permanently. 6 figures.

  12. Collective field accelerator

    DOEpatents

    Luce, John S.

    1978-01-01

    A collective field accelerator which operates with a vacuum diode and utilizes a grooved cathode and a dielectric anode that operates with a relativistic electron beam with a .nu./.gamma. of .about. 1, and a plurality of dielectric lenses having an axial magnetic field thereabout to focus the collectively accelerated electrons and ions which are ejected from the anode. The anode and lenses operate as unoptimized r-f cavities which modulate and focus the beam.

  13. Accelerators for America's Future

    NASA Astrophysics Data System (ADS)

    Bai, Mei

    2016-03-01

    Particle accelerator, a powerful tool to energize beams of charged particles to a desired speed and energy, has been the working horse for investigating the fundamental structure of matter and fundermental laws of nature. Most known examples are the 2-mile long Stanford Linear Accelerator at SLAC, the high energy proton and anti-proton collider Tevatron at FermiLab, and Large Hadron Collider that is currently under operation at CERN. During the less than a century development of accelerator science and technology that led to a dazzling list of discoveries, particle accelerators have also found various applications beyond particle and nuclear physics research, and become an indispensible part of the economy. Today, one can find a particle accelerator at almost every corner of our lives, ranging from the x-ray machine at the airport security to radiation diagnostic and therapy in hospitals. This presentation will give a brief introduction of the applications of this powerful tool in fundermental research as well as in industry. Challenges in accelerator science and technology will also be briefly presented

  14. Hearing on National Centers for Personal Computers in Education. Hearing before the Subcommittee on Elementary, Secondary and Vocational Education of the Committee on Education and Labor, House of Representatives, Ninety-Eighth Congress, First Session on H.R. 1134 to Amend Title III of the Elementary and Secondary Education Act of 1965 to Provide for One or More National Centers for Personal Computers in Education.

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. House Committee on Education and Labor.

    This hearing presents the text of House Resolution 1134, related testimony, prepared statements, and supplementary materials. A statement by Tom Downey, a congressional representative from New York State and the introducer of the bill, is followed by a prepared statement, two articles, and testimony by Ludwig Braun of the Computer Science…

  15. Accelerated partial breast irradiation utilizing brachytherapy: patient selection and workflow

    PubMed Central

    Wobb, Jessica; Manyam, Bindu; Khan, Atif; Vicini, Frank

    2016-01-01

    Accelerated partial breast irradiation (APBI) represents an evolving technique that is a standard of care option in appropriately selected woman following breast conserving surgery. While multiple techniques now exist to deliver APBI, interstitial brachytherapy represents the technique used in several randomized trials (National Institute of Oncology, GEC-ESTRO). More recently, many centers have adopted applicator-based brachytherapy to deliver APBI due to the technical complexities of interstitial brachytherapy. The purpose of this article is to review methods to evaluate and select patients for APBI, as well as to define potential workflow mechanisms that allow for the safe and effective delivery of APBI. Multiple consensus statements have been developed to guide clinicians on determining appropriate candidates for APBI. However, recent studies have demonstrated that these guidelines fail to stratify patients according to the risk of local recurrence, and updated guidelines are expected in the years to come. Critical elements of workflow to ensure safe and effective delivery of APBI include a multidisciplinary approach and evaluation, optimization of target coverage and adherence to normal tissue guideline constraints, and proper quality assurance methods. PMID:26985202

  16. Representing culture in interstellar messages

    NASA Astrophysics Data System (ADS)

    Vakoch, Douglas A.

    2008-09-01

    As scholars involved with the Search for Extraterrestrial Intelligence (SETI) have contemplated how we might portray humankind in any messages sent to civilizations beyond Earth, one of the challenges they face is adequately representing the diversity of human cultures. For example, in a 2003 workshop in Paris sponsored by the SETI Institute, the International Academy of Astronautics (IAA) SETI Permanent Study Group, the International Society for the Arts, Sciences and Technology (ISAST), and the John Templeton Foundation, a varied group of artists, scientists, and scholars from the humanities considered how to encode notions of altruism in interstellar messages . Though the group represented 10 countries, most were from Europe and North America, leading to the group's recommendation that subsequent discussions on the topic should include more globally representative perspectives. As a result, the IAA Study Group on Interstellar Message Construction and the SETI Institute sponsored a follow-up workshop in Santa Fe, New Mexico, USA in February 2005. The Santa Fe workshop brought together scholars from a range of disciplines including anthropology, archaeology, chemistry, communication science, philosophy, and psychology. Participants included scholars familiar with interstellar message design as well as specialists in cross-cultural research who had participated in the Symposium on Altruism in Cross-cultural Perspective, held just prior to the workshop during the annual conference of the Society for Cross-cultural Research . The workshop included discussion of how cultural understandings of altruism can complement and critique the more biologically based models of altruism proposed for interstellar messages at the 2003 Paris workshop. This paper, written by the chair of both the Paris and Santa Fe workshops, will explore the challenges of communicating concepts of altruism that draw on both biological

  17. Collaboration tools for the global accelerator network: Workshop Report

    SciTech Connect

    Agarwal, Deborah; Olson, Gary; Olson, Judy

    2002-09-15

    The concept of a ''Global Accelerator Network'' (GAN) has been put forward as a means for inter-regional collaboration in the operation of internationally constructed and operated frontier accelerator facilities. A workshop was held to allow representatives of the accelerator community and of the collaboratory development community to meet and discuss collaboration tools for the GAN environment. This workshop, called the Collaboration Tools for the Global Accelerator Network (GAN) Workshop, was held on August 26, 2002 at Lawrence Berkeley National Laboratory. The goal was to provide input about collaboration tools in general and to provide a strawman for the GAN collaborative tools environment. The participants at the workshop represented accelerator physicists, high-energy physicists, operations, technology tool developers, and social scientists that study scientific collaboration.

  18. Judgments of and by Representativeness

    DTIC Science & Technology

    1981-05-15

    Keprt 0 Judgments Of and By Representativeness,,I Jan. , *80agoAprO &1 i, 7. A. COPATaNRA ___ N00014-79-C-0077 Am;os /ftversky - ail hea S . PERFORMING...value and a variable; ..4 an instance and a category; I& a sample and a population; 4(1 an effect and a cause. The principles of representativenes...reduces it probability. Several studies of judgment are reported in which naive and sophi- DD I FjA017 1473 ITorION OF I Nov S IIS isoSOLETE Unclassified S

  19. Workforce Investment Act: Coordination between TANF Programs and One-Stop Centers Is Increasing, but Challenges Remain. Statement of Sigurd R. Nilsen, Director, Education, Workforce, and Income Security Issues [to the] Subcommittee on 21st Century Competitiveness, Committee on Education and the Workforce, House of Representatives.

    ERIC Educational Resources Information Center

    Nilsen, Sigurd R.

    The General Accounting Office assessed the extent to which states were coordinating their Temporary Assistance for Needy Families (TANF) services with their one-stop centers. Data were gathered through the following activities: (1) an autumn 2001 survey of workforce development agency officials in all 50 states and a similar survey conducted in…

  20. Radiobiological effectiveness of laser accelerated electrons in comparison to electron beams from a conventional linear accelerator.

    PubMed

    Laschinsky, Lydia; Baumann, Michael; Beyreuther, Elke; Enghardt, Wolfgang; Kaluza, Malte; Karsch, Leonhard; Lessmann, Elisabeth; Naumburger, Doreen; Nicolai, Maria; Richter, Christian; Sauerbrey, Roland; Schlenvoigt, Hans-Peter; Pawelke, Jörg

    2012-01-01

    The notable progress in laser particle acceleration technology promises potential medical application in cancer therapy through compact and cost effective laser devices that are suitable for already existing clinics. Previously, consequences on the radiobiological response by laser driven particle beams characterised by an ultra high peak dose rate have to be investigated. Therefore, tumour and non-malignant cells were irradiated with pulsed laser accelerated electrons at the JETI facility for the comparison with continuous electrons of a conventional therapy LINAC. Dose response curves were measured for the biological endpoints clonogenic survival and residual DNA double strand breaks. The overall results show no significant differences in radiobiological response for in vitro cell experiments between laser accelerated pulsed and clinical used electron beams. These first systematic in vitro cell response studies with precise dosimetry to laser driven electron beams represent a first step toward the long term aim of the application of laser accelerated particles in radiotherapy.

  1. 42 CFR 422.1010 - Authority of representatives.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 3 2012-10-01 2012-10-01 false Authority of representatives. 422.1010 Section 422.1010 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES... law in any proceedings affecting that party to the same extent as the party; and (3)...

  2. 42 CFR 423.657 - Authority of representatives.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 3 2012-10-01 2012-10-01 false Authority of representatives. 423.657 Section 423.657 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES... to facts and law in any proceedings affecting that party; and (3) Obtains information to the...

  3. 42 CFR 422.674 - Authority of representatives.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 3 2012-10-01 2012-10-01 false Authority of representatives. 422.674 Section 422.674 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES... and law in any proceedings affecting that party; and (3) Obtains information to the same extent as...

  4. 42 CFR 423.656 - Appointment of representatives.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 3 2012-10-01 2012-10-01 false Appointment of representatives. 423.656 Section 423.656 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES... or otherwise prohibited by law....

  5. 42 CFR 405.871 - Qualifications of representatives.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Qualifications of representatives. 405.871 Section 405.871 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES MEDICARE PROGRAM FEDERAL HEALTH INSURANCE FOR THE AGED AND DISABLED Appeals Under the...

  6. Center for beam physics 1996-1997

    SciTech Connect

    1997-02-01

    The Center for Beam Physics (CBP) is a multidisciplinary research and development unit in the Accelerator and Fusion Research Division at the Ernest Orlando Lawrence Berkeley National Laboratory of the University of California. At the heart of the Center`s mission is the fundamental quest for mechanisms of acceleration, radiation, transport, and focusing of energy and information. Special features of the Center`s program include addressing R&D issues needing long development time and providing a platform for conception, initiation, and support of institutional projects based on beams. The Center brings to bear a significant amount of diverse, complementary, and self-sufficient expertise in accelerator physics, synchrotron radiation, advanced microwave techniques, plasma physics, optics, and lasers on the forefront R&D issues in particle and photon beam research. In addition to functioning as a clearinghouse for novel ideas and concepts and related R&D (e.g., various theoretical and experimental studies in beam physics such as nonlinear dynamics, phase space control, laser-beam-plasma interaction, free-electron lasers, optics, and instrumentation), the Center provides significant support to Laboratory facilities and initiatives. This roster and annual report provides a glimpse of the scientists, engineers, technical support, students, and administrative staff that make up the CBP`s outstanding team and gives a flavor of their multifaceted activities during 1996 and 1997.

  7. Evidence for particle acceleration during magnetospheric substorms

    NASA Technical Reports Server (NTRS)

    Lopez, Ramon E.; Baker, Daniel N.

    1994-01-01

    Magnetospheric substorms represent the episodic dissipation of energy stored in the geomagnetic tail that was previously extracted from the solar wind. This energy release produces activity throughout the entire magnetosphere-ionosphere system, and it results in a wide variety of phenomena such as auroral intensifications and the generation of new current systems. All of these phenomena involve the acceleration of particles, sometimes up to several MeV. We present a brief overview of substorm phenomenology. We then review some of the evidence for particle acceleration in Earth's magnetosphere during substorms. Such in-situ observations in this most accessible of all cosmic plasma domains may hold important clues to understanding acceleration processes in more distant astrophysical systems.

  8. Laser Ion Acceleration Control

    NASA Astrophysics Data System (ADS)

    Kawata, Shigeo; Nagashima, T.; Izumiyama, T.; Sato, D.; Takano, M.; Barada, D.; Ma, Y. Y.; Gu, Y. J.; Kong, Q.; Wang, P. X.; Wang, W. M.

    2013-10-01

    An intense femtosecond pulsed laser is employed to accelerate ions. The issues in the laser ion accelerator include the energy efficiency from the laser to the ions, the ion beam collimation, the ion energy spectrum control, the ion beam bunching, the ion particle energy control, etc. In the study particle computer simulations were performed to solve the issues, and each component was designed to control the ion beam quality. When an intense laser illuminates a target, electrons in the target are accelerated and leave from the target; temporarily a strong electric field is formed between the high-energy electrons and the target ions, and the target ions are accelerated. The energy efficiency from the laser to ions was improved by using a solid target with a fine sub-wavelength structure or by a near critical density gas plasma. The ion beam collimation was realized by holes behind the solid target. The control of the ion energy spectrum and the ion particle energy, and the ion beam bunching were successfully realized by a multi-stage laser-target interaction. The present study proposed a novel concept for a future compact laser ion accelerator, based on each component study required to control the ion beam quality and parameters. Partly supported by JSPS, MEXT, CORE, Japan/US Cooperation program, ASHULA and ILE/Osaka University.

  9. Electrostatic Plasma Accelerator (EPA)

    NASA Technical Reports Server (NTRS)

    Brophy, John R.; Aston, Graeme

    1989-01-01

    The Electrostatic Plasma Accelerator (EPA) is a thruster concept which promises specific impulse levels between low power arcjets and those of the ion engine while retaining the relative simplicity of the arcjet. The EPA thruster produces thrust through the electrostatic acceleration of a moderately dense plasma. No accelerating electrodes are used and the specific impulse is a direct function of the applied discharge voltage and the propellant atomic mass. The goal of the present program is to demonstrate feasibility of the EPA thruster concept through experimental and theoretical investigations of the EPA acceleration mechanism and discharge chamber performance. Experimental investigations will include operating the test bed ion (TBI) engine as an EPA thruster and parametrically varying the thruster geometry and operating conditions to quantify the electrostatic plasma acceleration effect. The theoretical investigations will include the development of a discharge chamber model which describes the relationships between the engine size, plasma properties, and overall performance. For the EPA thruster to be a viable propulsion concept, overall thruster efficiencies approaching 30% with specific impulses approaching 1000 s must be achieved.

  10. Advanced accelerator theory development

    SciTech Connect

    Sampayan, S.E.; Houck, T.L.; Poole, B.; Tishchenko, N.; Vitello, P.A.; Wang, I.

    1998-02-09

    A new accelerator technology, the dielectric wall accelerator (DWA), is potentially an ultra compact accelerator/pulsed power driver. This new accelerator relies on three new components: the ultra-high gradient insulator, the asymmetric Blumlein and low jitter switches. In this report, we focused our attention on the first two components of the DWA system the insulators and the asymmetric Blumlein. First, we sought to develop the necessary design tools to model and scale the behavior of the high gradient insulator. To perform this task we concentrated on modeling the discharge processes (i.e., initiation and creation of the surface discharge). In addition, because these high gradient structures exhibit favorable microwave properties in certain accelerator configurations, we performed experiments and calculations to determine the relevant electromagnetic properties. Second, we performed circuit modeling to understand energy coupling to dynamic loads by the asymmetric Blumlein. Further, we have experimentally observed a non-linear coupling effect in certain asymmetric Blumlein configurations. That is, as these structures are stacked into a complete module, the output voltage does not sum linearly and a lower than expected output voltage results. Although we solved this effect experimentally, we performed calculations to understand this effect more fully to allow better optimization of this DWA pulse-forming line system.

  11. Core Research Center

    USGS Publications Warehouse

    Hicks, Joshua; Adrian, Betty

    2009-01-01

    The Core Research Center (CRC) of the U.S. Geological Survey (USGS), located at the Denver Federal Center in Lakewood, Colo., currently houses rock core from more than 8,500 boreholes representing about 1.7 million feet of rock core from 35 States and cuttings from 54,000 boreholes representing 238 million feet of drilling in 28 States. Although most of the boreholes are located in the Rocky Mountain region, the geologic and geographic diversity of samples have helped the CRC become one of the largest and most heavily used public core repositories in the United States. Many of the boreholes represented in the collection were drilled for energy and mineral exploration, and many of the cores and cuttings were donated to the CRC by private companies in these industries. Some cores and cuttings were collected by the USGS along with other government agencies. Approximately one-half of the cores are slabbed and photographed. More than 18,000 thin sections and a large volume of analytical data from the cores and cuttings are also accessible. A growing collection of digital images of the cores are also becoming available on the CRC Web site Internet http://geology.cr.usgs.gov/crc/.

  12. Field Work Proposal: PUBLIC OUTREACH EVENT FOR ACCELERATOR STEWARDSHIP TEST FACILITY PILOT PROGRAM

    SciTech Connect

    Hutton, Andrew; Areti, Hari

    2015-03-05

    Jefferson Lab’s outreach efforts towards the goals of Accelerator Stewardship Test Facility Pilot Program consist of the lab’s efforts in three venues. The first venue, at the end of March is to meet with the members of Virginia Tech Corporate Research Center (VTCRC) (http://www.vtcrc.com/tenant-directory/) in Blacksburg, Virginia. Of the nearly 160 members, we expect that many engineering companies (including mechanical, electrical, bio, software) will be present. To this group, we will describe the capabilities of Jefferson Lab’s accelerator infrastructure. The description will include not only the facilities but also the intellectual expertise. No funding is requested for this effort. The second venue is to reach the industrial exhibitors at the 6th International Particle Accelerator Conference (IPAC’15). Jefferson Lab will host a booth at the conference to reach out to the >75 industrial exhibitors (https://www.jlab.org/conferences/ipac2015/SponsorsExhibitors.php) who represent a wide range of technologies. A number of these industries could benefit if they can access Jefferson Lab’s accelerator infrastructure. In addition to the booth, where written material will be available, we plan to arrange a session A/V presentation to the industry exhibitors. The booth will be hosted by Jefferson Lab’s Public Relations staff, assisted on a rotating basis by the lab’s scientists and engineers. The budget with IPAC’15 designations represents the request for funds for this effort. The third venue is the gathering of Southeastern Universities Research Association (SURA) university presidents. Here we plan to reach the research departments of the universities who can benefit by availing themselves to the infrastructure (material sciences, engineering, medical schools, material sciences, to name a few). Funding is requested to allow for attendance at the SURA Board Meeting. We are coordinating with DOE regarding these costs to raise the projected conference

  13. Plasma-based accelerator structures

    SciTech Connect

    Schroeder, Carl B.

    1999-12-01

    Plasma-based accelerators have the ability to sustain extremely large accelerating gradients, with possible high-energy physics applications. This dissertation further develops the theory of plasma-based accelerators by addressing three topics: the performance of a hollow plasma channel as an accelerating structure, the generation of ultrashort electron bunches, and the propagation of laser pulses is underdense plasmas.

  14. Perturbations for transient acceleration

    SciTech Connect

    Vargas, Cristofher Zuñiga; Zimdahl, Winfried; Hipólito-Ricaldi, Wiliam S. E-mail: hipolito@ceunes.ufes.br

    2012-04-01

    According to the standard ΛCDM model, the accelerated expansion of the Universe will go on forever. Motivated by recent observational results, we explore the possibility of a finite phase of acceleration which asymptotically approaches another period of decelerated expansion. Extending an earlier study on a corresponding homogeneous and isotropic dynamics, in which interactions between dark matter and dark energy are crucial, the present paper also investigates the dynamics of the matter perturbations both on the Newtonian and General Relativistic (GR) levels and quantifies the potential relevance of perturbations of the dark-energy component. In the background, the model is tested against the Supernova type Ia (SNIa) data of the Constitution set and on the perturbative level against growth rate data, among them those of the WiggleZ survey, and the data of the 2dFGRS project. Our results indicate that a transient phase of accelerated expansion is not excluded by current observations.

  15. Uniform acceleration in general relativity

    NASA Astrophysics Data System (ADS)

    Friedman, Yaakov; Scarr, Tzvi

    2015-10-01

    We extend de la Fuente and Romero's (Gen Relativ Gravit 47:33, 2015) defining equation for uniform acceleration in a general curved spacetime from linear acceleration to the full Lorentz covariant uniform acceleration. In a flat spacetime background, we have explicit solutions. We use generalized Fermi-Walker transport to parallel transport the Frenet basis along the trajectory. In flat spacetime, we obtain velocity and acceleration transformations from a uniformly accelerated system to an inertial system. We obtain the time dilation between accelerated clocks. We apply our acceleration transformations to the motion of a charged particle in a constant electromagnetic field and recover the Lorentz-Abraham-Dirac equation.

  16. Microelectromechanical acceleration-sensing apparatus

    DOEpatents

    Lee, Robb M.; Shul, Randy J.; Polosky, Marc A.; Hoke, Darren A.; Vernon, George E.

    2006-12-12

    An acceleration-sensing apparatus is disclosed which includes a moveable shuttle (i.e. a suspended mass) and a latch for capturing and holding the shuttle when an acceleration event is sensed above a predetermined threshold level. The acceleration-sensing apparatus provides a switch closure upon sensing the acceleration event and remains latched in place thereafter. Examples of the acceleration-sensing apparatus are provided which are responsive to an acceleration component in a single direction (i.e. a single-sided device) or to two oppositely-directed acceleration components (i.e. a dual-sided device). A two-stage acceleration-sensing apparatus is also disclosed which can sense two acceleration events separated in time. The acceleration-sensing apparatus of the present invention has applications, for example, in an automotive airbag deployment system.

  17. Diffusive Shock Acceleration

    NASA Astrophysics Data System (ADS)

    Baring, Matthew

    2003-04-01

    The process of diffusive acceleration of charged particles in shocked plasmas is widely invoked in astrophysics to account for the ubiquitous presence of signatures of non-thermal relativistic electrons and ions in the universe. This statistical energization mechanism, manifested in turbulent media, was first posited by Enrico Fermi in 1949 to explain the observed cosmic ray population, which exhibits an almost power-law distribution in rigidity. The absence of a momentum scale is a key characteristic of diffusive shock acceleration, and astrophysical systems generally only impose scales at the injection (low energy) and loss (high energy) ends of the particle spectrum. The existence of structure in the cosmic ray spectrum (the "knee") at around 3000 TeV has promoted contentions that there are at least two origins for cosmic rays, a galactic one supplying those up to the knee, and perhaps an extragalactic one that can explain even the ultra-high energy cosmic rays (UHECRs) seen at 1-300 EeV. Accounting for the UHECRs with familiar astrophysical sites of acceleration has historically proven difficult due to the need to assume high magnetic fields in order to reduce the shortest diffusive acceleration timescale, the ion gyroperiod, to meaningful values. Yet active galaxies and gamma-ray bursts remain strong and interesting candidate sources for UHECRs, turning the theoretical focus to relativistic shocks. This review summarizes properties of diffusive shock acceleration that are salient to the issue of UHECR generation. These include spectral indices, anisotropies, acceleration efficencies and timescales, as functions of the shock speed and mean field orientation, and also the degree of field turbulence. Astrophysical sites for UHECR production are also critiqued.

  18. Liquid cooled data center design selection

    SciTech Connect

    Chainer, Timothy J.; Iyengar, Madhusudan K.; Parida, Pritish R.

    2016-09-13

    Input data, specifying aspects of a thermal design of a liquid cooled data center, is obtained. The input data includes data indicative of ambient outdoor temperature for a location of the data center; and/or data representing workload power dissipation for the data center. The input data is evaluated to obtain performance of the data center thermal design. The performance includes cooling energy usage; and/or one pertinent temperature associated with the data center. The performance of the data center thermal design is output.

  19. 'Light Sail' Acceleration Reexamined

    SciTech Connect

    Macchi, Andrea; Veghini, Silvia; Pegoraro, Francesco

    2009-08-21

    The dynamics of the acceleration of ultrathin foil targets by the radiation pressure of superintense, circularly polarized laser pulses is investigated by analytical modeling and particle-in-cell simulations. By addressing self-induced transparency and charge separation effects, it is shown that for 'optimal' values of the foil thickness only a thin layer at the rear side is accelerated by radiation pressure. The simple 'light sail' model gives a good estimate of the energy per nucleon, but overestimates the conversion efficiency of laser energy into monoenergetic ions.

  20. HIGH GRADIENT INDUCTION ACCELERATOR

    SciTech Connect

    Caporaso, G J; Sampayan, S; Chen, Y; Blackfield, D; Harris, J; Hawkins, S; Holmes, C; Krogh, M; Nelson, S; Nunnally, W; Paul, A; Poole, B; Rhodes, M; Sanders, D; Selenes, K; Sullivan, J; Wang, L; Watson, J

    2007-06-21

    A new type of compact induction accelerator is under development at the Lawrence Livermore National Laboratory that promises to increase the average accelerating gradient by at least an order of magnitude over that of existing induction machines. The machine is based on the use of high gradient vacuum insulators, advanced dielectric materials and switches and is stimulated by the desire for compact flash x-ray radiography sources. Research describing an extreme variant of this technology aimed at proton therapy for cancer will be described. Progress in applying this technology to several applications will be reviewed.

  1. "Light sail" acceleration reexamined.

    PubMed

    Macchi, Andrea; Veghini, Silvia; Pegoraro, Francesco

    2009-08-21

    The dynamics of the acceleration of ultrathin foil targets by the radiation pressure of superintense, circularly polarized laser pulses is investigated by analytical modeling and particle-in-cell simulations. By addressing self-induced transparency and charge separation effects, it is shown that for "optimal" values of the foil thickness only a thin layer at the rear side is accelerated by radiation pressure. The simple "light sail" model gives a good estimate of the energy per nucleon, but overestimates the conversion efficiency of laser energy into monoenergetic ions.

  2. High intensity hadron accelerators

    SciTech Connect

    Teng, L.C.

    1989-05-01

    This rapporteur report consists mainly of two parts. Part I is an abridged review of the status of all High Intensity Hadron Accelerator projects in the world in semi-tabulated form for quick reference and comparison. Part II is a brief discussion of the salient features of the different technologies involved. The discussion is based mainly on my personal experiences and opinions, tempered, I hope, by the discussions I participated in in the various parallel sessions of the workshop. In addition, appended at the end is my evaluation and expression of the merits of high intensity hadron accelerators as research facilities for nuclear and particle physics.

  3. Superdense Coding with Uniformly Accelerated Particle

    NASA Astrophysics Data System (ADS)

    Farahmand, Mehrnoosh; Mohammadzadeh, Hosein; Mehri-Dehnavi, Hossein; Rahimi, Robabeh

    2017-03-01

    We study superdense coding with uniformly accelerated particle in single mode approximation and beyond single mode approximation. We use four different functions, the capacity of superdense coding, negativity, discord and the probability of success for evaluating the final results. In single mode approximation, all the four functions behave as expected, however in beyond single mode approximation, except the probability of success, the other three functions represent peculiar behaviors at least for special ranges where the beyond single mode approximation is strong.

  4. Want change? Call your representative

    NASA Astrophysics Data System (ADS)

    Fischhoff, Ilya R.

    2011-07-01

    During my tenure as an AGU Congressional Science Fellow, which began in September 2010 and continues until November 2011, my time has been shared between working with the U.S. House of Representatives Natural Resource Committee Democratic staff and in the office of Rep. Ed Markey (D-Mass., ranking Democrat on the committee). I appreciate getting to work with staff, fellows, and interns who inspire me, make me laugh, and know their issues cold. Much of my work on the committee is related to fish, wildlife, oceans, lands, and water issues and is directly related to my background in ecology and evolutionary biology (I studied zebra ecology and behavior in Kenya). My assignments have included asking the Environmental Protection Agency (EPA) about why it has not changed the allowed usage of certain pesticides that the National Marine Fisheries Service has found to jeopardize the recovery of endangered Pacific salmon; helping to identify research needs and management options to combat the swiftly spreading and catastrophic white nose syndrome in North American bats; and inquiring as to whether a captive-ape welfare bill, if passed without amendment, could thwart development of a vaccine to stop the Ebola virus from continuing to cause mass mortality in endangered wild apes.

  5. Particle accelerations and current structures of Weibel and Filamentation instabilities

    NASA Astrophysics Data System (ADS)

    Ryu, C. M.; Huynh, C. T.

    2015-12-01

    Particle accelerations of the Wibel instability (WI) and the Filamentation instability(FI) are studied by using PIC simuations, comparing them side-by-side. Although two instabilities are almost identical in the linear growth phase, significant differences are found in the nonlinear phase in their particle accelerations and current structures. The FI shows enhanced electron acceleration, whereas particle acceleration is almost absent in the WI. The different particle accelerations between the FI and the WI seem to be associated with their different current structures; a hollow electron current structure for the FI and a center filled current structure for that of the WI. Different electron distributions seem to bring in different current filament structures, eventually leading to different magnetic characteristics.

  6. Radioisotope Dating with Accelerators.

    ERIC Educational Resources Information Center

    Muller, Richard A.

    1979-01-01

    Explains a new method of detecting radioactive isotopes by counting their accelerated ions rather than the atoms that decay during the counting period. This method increases the sensitivity by several orders of magnitude, and allows one to find the ages of much older and smaller samples. (GA)

  7. Accelerated Management Development

    ERIC Educational Resources Information Center

    Munn, Kenn

    1974-01-01

    Western Electric's accelerated management development program for hand picked college graduate students consists of a high risk training project in which the management candidate accomplishes his task or is terminated. The success of such projects puts candidates in third level management in seven years or half the normal time. (DS)

  8. Combined generating-accelerating buncher for compact linear accelerators

    NASA Astrophysics Data System (ADS)

    Savin, E. A.; Matsievskiy, S. V.; Sobenin, N. P.; Sokolov, I. D.; Zavadtsev, A. A.

    2016-09-01

    Described in the previous article [1] method of the power extraction from the modulated electron beam has been applied to the compact standing wave electron linear accelerator feeding system, which doesnt require any connection waveguides between the power source and the accelerator itself [2]. Generating and accelerating bunches meet in the hybrid accelerating cell operating at TM020 mode, thus the accelerating module is placed on the axis of the generating module, which consists from the pulsed high voltage electron sources and electrons dumps. This combination makes the accelerator very compact in size which is very valuable for the modern applications such as portable inspection sources. Simulations and geometry cold tests are presented.

  9. Systems and methods for cylindrical hall thrusters with independently controllable ionization and acceleration stages

    DOEpatents

    Diamant, Kevin David; Raitses, Yevgeny; Fisch, Nathaniel Joseph

    2014-05-13

    Systems and methods may be provided for cylindrical Hall thrusters with independently controllable ionization and acceleration stages. The systems and methods may include a cylindrical channel having a center axial direction, a gas inlet for directing ionizable gas to an ionization section of the cylindrical channel, an ionization device that ionizes at least a portion of the ionizable gas within the ionization section to generate ionized gas, and an acceleration device distinct from the ionization device. The acceleration device may provide an axial electric field for an acceleration section of the cylindrical channel to accelerate the ionized gas through the acceleration section, where the axial electric field has an axial direction in relation to the center axial direction. The ionization section and the acceleration section of the cylindrical channel may be substantially non-overlapping.

  10. Measurement of Electron Clouds in Large Accelerators by Microwave Dispersion

    SciTech Connect

    De Santis, S.; Byrd, J.M.; Caspers, F.; Krasnykh, A.; Kroyer, T.; Pivi, M.T.F.; Sonnad, K.G.; /LBL, Berkeley

    2008-03-19

    Clouds of low energy electrons in the vacuum beam pipes of accelerators of positively charged particle beams present a serious limitation for operation at high currents. Furthermore, it is difficult to probe their density over substantial lengths of the beam pipe. We have developed a novel technique to directly measure the electron cloud density via the phase shift induced in a TE wave transmitted over a section of the accelerator and used it to measure the average electron cloud density over a 50 m section in the positron ring of the PEP-II collider at the Stanford Linear Accelerator Center.

  11. Measurement of electron clouds in large accelerators by microwave dispersion.

    PubMed

    De Santis, S; Byrd, J M; Caspers, F; Krasnykh, A; Kroyer, T; Pivi, M T F; Sonnad, K G

    2008-03-07

    Clouds of low energy electrons in the vacuum beam pipes of accelerators of positively charged particle beams present a serious limitation for operation at high currents. Furthermore, it is difficult to probe their density over substantial lengths of the beam pipe. We have developed a novel technique to directly measure the electron cloud density via the phase shift induced in a TE wave transmitted over a section of the accelerator and used it to measure the average electron cloud density over a 50 m section in the positron ring of the PEP-II collider at the Stanford Linear Accelerator Center.

  12. Accelerated simulation methods for plasma kinetics

    NASA Astrophysics Data System (ADS)

    Caflisch, Russel

    2016-11-01

    Collisional kinetics is a multiscale phenomenon due to the disparity between the continuum (fluid) and the collisional (particle) length scales. This paper describes a class of simulation methods for gases and plasmas, and acceleration techniques for improving their speed and accuracy. Starting from the Landau-Fokker-Planck equation for plasmas, the focus will be on a binary collision model that is solved using a Direct Simulation Monte Carlo (DSMC) method. Acceleration of this method is achieved by coupling the particle method to a continuum fluid description. The velocity distribution function f is represented as a combination of a Maxwellian M (the thermal component) and a set of discrete particles fp (the kinetic component). For systems that are close to (local) equilibrium, this reduces the number N of simulated particles that are required to represent f for a given level of accuracy. We present two methods for exploiting this representation. In the first method, equilibration of particles in fp, as well as disequilibration of particles from M, due to the collision process, is represented by a thermalization/dethermalization step that employs an entropy criterion. Efficiency of the representation is greatly increased by inclusion of particles with negative weights. This significantly complicates the simulation, but the second method is a tractable approach for negatively weighted particles. The accelerated simulation method is compared with standard PIC-DSMC method for both spatially homogeneous problems such as a bump-on-tail and inhomogeneous problems such as nonlinear Landau damping.

  13. Menopause accelerates biological aging

    PubMed Central

    Levine, Morgan E.; Lu, Ake T.; Chen, Brian H.; Hernandez, Dena G.; Singleton, Andrew B.; Ferrucci, Luigi; Bandinelli, Stefania; Salfati, Elias; Manson, JoAnn E.; Quach, Austin; Kusters, Cynthia D. J.; Kuh, Diana; Wong, Andrew; Teschendorff, Andrew E.; Widschwendter, Martin; Ritz, Beate R.; Absher, Devin; Assimes, Themistocles L.; Horvath, Steve

    2016-01-01

    Although epigenetic processes have been linked to aging and disease in other systems, it is not yet known whether they relate to reproductive aging. Recently, we developed a highly accurate epigenetic biomarker of age (known as the “epigenetic clock”), which is based on DNA methylation levels. Here we carry out an epigenetic clock analysis of blood, saliva, and buccal epithelium using data from four large studies: the Women's Health Initiative (n = 1,864); Invecchiare nel Chianti (n = 200); Parkinson's disease, Environment, and Genes (n = 256); and the United Kingdom Medical Research Council National Survey of Health and Development (n = 790). We find that increased epigenetic age acceleration in blood is significantly associated with earlier menopause (P = 0.00091), bilateral oophorectomy (P = 0.0018), and a longer time since menopause (P = 0.017). Conversely, epigenetic age acceleration in buccal epithelium and saliva do not relate to age at menopause; however, a higher epigenetic age in saliva is exhibited in women who undergo bilateral oophorectomy (P = 0.0079), while a lower epigenetic age in buccal epithelium was found for women who underwent menopausal hormone therapy (P = 0.00078). Using genetic data, we find evidence of coheritability between age at menopause and epigenetic age acceleration in blood. Using Mendelian randomization analysis, we find that two SNPs that are highly associated with age at menopause exhibit a significant association with epigenetic age acceleration. Overall, our Mendelian randomization approach and other lines of evidence suggest that menopause accelerates epigenetic aging of blood, but mechanistic studies will be needed to dissect cause-and-effect relationships further. PMID:27457926

  14. Stacked insulator induction accelerator gaps

    SciTech Connect

    Houck, T.I.; Westenskow, G.A.; Kim, J.S.; Eylon, S.; Henestroza, E.; Yu, S.S.; Vanecek, D.

    1997-05-01

    Stacked insulators, with alternating layers of insulating material and conducting film, have been shown to support high surface electrical field stresses. We have investigated the application of the stacked insulator technology to the design of induction accelerator modules for the Relativistic-Klystron Two-Beam Accelerator program. The rf properties of the accelerating gaps using stacked insulators, particularly the impedance at frequencies above the beam pipe cutoff frequency, are investigated. Low impedance is critical for Relativistic-Klystron Two-Beam Accelerator applications where a high current, bunched beam is trsnsported through many accelerating gaps. An induction accelerator module designs using a stacked insulator is presented.

  15. The FAST (FRC Acceleration Space Thruster) Experiment

    NASA Technical Reports Server (NTRS)

    Martin, Adam; Eskridge, R.; Lee, M.; Richeson, J.; Smith, J.; Thio, Y. C. F.; Slough, J.; Rodgers, Stephen L. (Technical Monitor)

    2001-01-01

    The Field Reverse Configuration (FRC) is a magnetized plasmoid that has been developed for use in magnetic confinement fusion. Several of its properties suggest that it may also be useful as a thruster for in-space propulsion. The FRC is a compact toroid that has only poloidal field, and is characterized by a high plasma beta = (P)/(B (sup 2) /2Mu0), the ratio of plasma pressure to magnetic field pressure, so that it makes efficient use of magnetic field to confine a plasma. In an FRC thruster, plasmoids would be repetitively formed and accelerated to high velocity; velocities of = 250 km/s (Isp = 25,000s) have already been achieved in fusion experiments. The FRC is inductively formed and accelerated, and so is not subject to the problem of electrode erosion. As the plasmoid may be accelerated over an extended length, it can in principle be made very efficient. And the achievable jet powers should be scalable to the MW range. A 10 kW thruster experiment - FAST (FRC Acceleration Space Thruster) has just started at the Marshall Space Flight Center. The design of FAST and the status of construction and operation will be presented.

  16. Fluid Physics in a Fluctuating Acceleration Environment

    NASA Technical Reports Server (NTRS)

    Thomson, J. Ross; Drolet, Francois; Vinals, Jorge

    1996-01-01

    We summarize several aspects of an ongoing investigation of the effects that stochastic residual accelerations (g-jitter) onboard spacecraft can have on experiments conducted in a microgravity environment. The residual acceleration field is modeled as a narrow band noise, characterized by three independent parameters: intensity (g(exp 2)), dominant angular frequency Omega, and characteristic correlation time tau. Realistic values for these parameters are obtained from an analysis of acceleration data corresponding to the SL-J mission, as recorded by the SAMS instruments. We then use the model to address the random motion of a solid particle suspended in an incompressible fluid subjected to such random accelerations. As an extension, the effect of jitter on coarsening of a solid-liquid mixture is briefly discussed, and corrections to diffusion controlled coarsening evaluated. We conclude that jitter will not be significant in the experiment 'Coarsening of solid-liquid mixtures' to be conducted in microgravity. Finally, modifications to the location of onset of instability in systems driven by a random force are discussed by extending the standard reduction to the center manifold to the stochastic case. Results pertaining to time-modulated oscillatory convection are briefly discussed.

  17. About TTC | NCI Technology Transfer Center | TTC

    Cancer.gov

    The National Cancer Institute’s Technology Transfer Center (TTC) facilitates partnerships between the NIH research laboratories and external partners, and helping to accelerate development of cutting-edge research by connecting our partners to NIH’s world-class facilities, resources, and discoveries. Contact us to learn more. | [google6f4cd5334ac394ab.html

  18. Mass spectrometry with accelerators.

    PubMed

    Litherland, A E; Zhao, X-L; Kieser, W E

    2011-01-01

    As one in a series of articles on Canadian contributions to mass spectrometry, this review begins with an outline of the history of accelerator mass spectrometry (AMS), noting roles played by researchers at three Canadian AMS laboratories. After a description of the unique features of AMS, three examples, (14)C, (10)Be, and (129)I are given to illustrate the methods. The capabilities of mass spectrometry have been extended by the addition of atomic isobar selection, molecular isobar attenuation, further ion acceleration, followed by ion detection and ion identification at essentially zero dark current or ion flux. This has been accomplished by exploiting the techniques and accelerators of atomic and nuclear physics. In 1939, the first principles of AMS were established using a cyclotron. In 1977 the selection of isobars in the ion source was established when it was shown that the (14)N(-) ion was very unstable, or extremely difficult to create, making a tandem electrostatic accelerator highly suitable for assisting the mass spectrometric measurement of the rare long-lived radioactive isotope (14)C in the environment. This observation, together with the large attenuation of the molecular isobars (13)CH(-) and (12)CH 2(-) during tandem acceleration and the observed very low background contamination from the ion source, was found to facilitate the mass spectrometry of (14)C to at least a level of (14)C/C ~ 6 × 10(-16), the equivalent of a radiocarbon age of 60,000 years. Tandem Accelerator Mass Spectrometry, or AMS, has now made possible the accurate radiocarbon dating of milligram-sized carbon samples by ion counting as well as dating and tracing with many other long-lived radioactive isotopes such as (10)Be, (26)Al, (36)Cl, and (129)I. The difficulty of obtaining large anion currents with low electron affinities and the difficulties of isobar separation, especially for the heavier mass ions, has prompted the use of molecular anions and the search for alternative

  19. Expanding wave solutions of the Einstein equations that induce an anomalous acceleration into the Standard Model of Cosmology.

    PubMed

    Temple, Blake; Smoller, Joel

    2009-08-25

    We derive a system of three coupled equations that implicitly defines a continuous one-parameter family of expanding wave solutions of the Einstein equations, such that the Friedmann universe associated with the pure radiation phase of the Standard Model of Cosmology is embedded as a single point in this family. By approximating solutions near the center to leading order in the Hubble length, the family reduces to an explicit one-parameter family of expanding spacetimes, given in closed form, that represents a perturbation of the Standard Model. By introducing a comoving coordinate system, we calculate the correction to the Hubble constant as well as the exact leading order quadratic correction to the redshift vs. luminosity relation for an observer at the center. The correction to redshift vs. luminosity entails an adjustable free parameter that introduces an anomalous acceleration. We conclude (by continuity) that corrections to the redshift vs. luminosity relation observed after the radiation phase of the Big Bang can be accounted for, at the leading order quadratic level, by adjustment of this free parameter. The next order correction is then a prediction. Since nonlinearities alone could actuate dissipation and decay in the conservation laws associated with the highly nonlinear radiation phase and since noninteracting expanding waves represent possible time-asymptotic wave patterns that could result, we propose to further investigate the possibility that these corrections to the Standard Model might be the source of the anomalous acceleration of the galaxies, an explanation not requiring the cosmological constant or dark energy.

  20. NASA New England Outreach Center

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The NASA New England Outreach Center in Nashua, New Hampshire was established to serve as a catalyst for heightening regional business awareness of NASA procurement, technology and commercialization opportunities. Emphasis is placed on small business participation, with the highest priority given to small disadvantaged businesses, women-owned businesses, HUBZone businesses, service disabled veteran owned businesses, and historically black colleges and universities and minority institutions. The Center assists firms and organizations to understand NASA requirements and to develop strategies to capture NASA related procurement and technology opportunities. The establishment of the NASA Outreach Center serves to stimulate business in a historically underserved area. NASA direct business awards have traditionally been highly present in the West, Midwest, South, and Southeast areas of the United States. The Center guides and assists businesses and organizations in the northeast to target opportunities within NASA and its prime contractors and capture business and technology opportunities. The Center employs an array of technology access, one-on-one meetings, seminars, site visits, and targeted conferences to acquaint Northeast firms and organizations with representatives from NASA and its prime contractors to learn about and discuss opportunities to do business and access the inventory of NASA technology. This stimulus of interaction also provides firms and organizations the opportunity to propose the use of their developed technology and ideas for current and future requirements at NASA. The Center provides a complement to the NASA Northeast Regional Technology Transfer Center in developing prospects for commercialization of NASA technology. In addition, the Center responds to local requests for assistance and NASA material and documents, and is available to address immediate concerns and needs in assessing opportunities, timely support to interact with NASA Centers on

  1. Review of ion accelerators

    SciTech Connect

    Alonso, J.

    1990-06-01

    The field of ion acceleration to higher energies has grown rapidly in the last years. Many new facilities as well as substantial upgrades of existing facilities have extended the mass and energy range of available beams. Perhaps more significant for the long-term development of the field has been the expansion in the applications of these beams, and the building of facilities dedicated to areas outside of nuclear physics. This review will cover many of these new developments. Emphasis will be placed on accelerators with final energies above 50 MeV/amu. Facilities such as superconducting cyclotrons and storage rings are adequately covered in other review papers, and so will not be covered here.

  2. Accelerator research studies

    SciTech Connect

    Not Available

    1992-01-01

    The Accelerator Research Studies program at the University of Maryland, sponsored by the Department of Energy under grant number DE-FG05-91ER40642, is currently in the first year of a three-year funding cycle. The program consists of the following three tasks: TASK A, Study of Transport and Longitudinal Compression of Intense, High-Brightness Beams, TASK B, Study of Collective Ion Acceleration by Intense Electron Beams and Pseudospark Produced High Brightness Electron Beams; TASK C, Study of a Gyroklystron High-power Microwave Source for Linear Colliders. In this report we document the progress that has been made during the past year for each of the three tasks.

  3. Commissioning the GTA accelerator

    SciTech Connect

    Sander, O.R.; Atkins, W.H.; Bolme, G.O.; Bowling, S.; Brown, S.; Cole, R.; Gilpatrick, J.D.; Garnett, R.; Guy, F.W.; Ingalls, W.B.; Johnson, K.F.; Kerstiens, D.; Little, C.; Lohsen, R.A.; Lloyd, S.; Lysenko, W.P.; Mottershead, C.T.; Neuschaefer, G.; Power, J.; Rusthoi, D.P.; Sandoval, D.P. Stevens, R.R. Jr.; Vaughn, G.; Wadlinger, E.A.; Yuan, V.; Connolly, R.; Weiss, R.; Saadatmand, K.

    1992-09-01

    The Ground Test Accelerator (GTA) is supported by the Strategic Defense command as part of their Neutral Particle Beam (NPB) program. Neutral particles have the advantage that in space they are unaffected by the earth`s magnetic field and travel in straight lines unless they enter the earth`s atmosphere and become charged by stripping. Heavy particles are difficult to stop and can probe the interior of space vehicles; hence, NPB can function as a discriminator between warheads and decoys. We are using GTA to resolve the physics and engineering issues related to accelerating, focusing, and steering a high-brightness, high-current H{sup -} beam and then neutralizing it. Our immediate goal is to produce a 24-MeV, 50mA device with a 2% duty factor.

  4. Commissioning the GTA accelerator

    SciTech Connect

    Sander, O.R.; Atkins, W.H.; Bolme, G.O.; Bowling, S.; Brown, S.; Cole, R.; Gilpatrick, J.D.; Garnett, R.; Guy, F.W.; Ingalls, W.B.; Johnson, K.F.; Kerstiens, D.; Little, C.; Lohsen, R.A.; Lloyd, S.; Lysenko, W.P.; Mottershead, C.T.; Neuschaefer, G.; Power, J.; Rusthoi, D.P.; Sandoval, D.P. Stevens, R.R. Jr.; Vaughn, G.; Wadlinger, E.A.; Yuan, V. ); Connolly, R.; Weiss, R. (Gr

    1992-01-01

    The Ground Test Accelerator (GTA) is supported by the Strategic Defense command as part of their Neutral Particle Beam (NPB) program. Neutral particles have the advantage that in space they are unaffected by the earth's magnetic field and travel in straight lines unless they enter the earth's atmosphere and become charged by stripping. Heavy particles are difficult to stop and can probe the interior of space vehicles; hence, NPB can function as a discriminator between warheads and decoys. We are using GTA to resolve the physics and engineering issues related to accelerating, focusing, and steering a high-brightness, high-current H{sup -} beam and then neutralizing it. Our immediate goal is to produce a 24-MeV, 50mA device with a 2% duty factor.

  5. Auroral ion acceleration

    NASA Astrophysics Data System (ADS)

    Shalimov, S. L.

    From the altitude of 500 km to 15 R sub E everywhere conic like distributions of H+, O+, He+ ions are moving upwards from the ionosphere along the geomagnetic field lines in the auroral zone. The distributed ions suggest the existence of ion transverse acceleration mechanisms (ITAM) acting below the observation point. The more plausible mechanisms are connected with the resonance of the type wave particle between ions and the observed EIC and LH waves and are also due to the existence of the local transverse electric fields in the ionoshere and the magnetosphere. The known ion transverse acceleration mechanisms were complemented by new results. The conical distributions of ionospheric ions at different altitudes in the auroral zone are pointed out.

  6. Review of accelerator instrumentation

    SciTech Connect

    Pellegrin, J.L.

    1980-05-01

    Some of the problems associated with the monitoring of accelerator beams, particularly storage rings' beams, are reviewed along with their most common solutions. The various electrode structures used for the measurement of beam current, beam position, and the detection of the bunches' transverse oscillations, yield pulses with sub-nanosecond widths. The electronics for the processing of these short pulses involves wide band techniques and circuits usually not readily available from industry or the integrated circuit market: passive or active, successive integrations, linear gating, sample-and-hold circuits with nanosecond acquisition time, etc. This report also presents the work performed recently for monitoring the ultrashort beams of colliding linear accelerators or single-pass colliders. To minimize the beam emittance, the beam position must be measured with a high resolution, and digitized on a pulse-to-pulse basis. Experimental results obtained with the Stanford two-mile Linac single bunches are included.

  7. Hardware Accelerated Simulated Radiography

    SciTech Connect

    Laney, D; Callahan, S; Max, N; Silva, C; Langer, S; Frank, R

    2005-04-12

    We present the application of hardware accelerated volume rendering algorithms to the simulation of radiographs as an aid to scientists designing experiments, validating simulation codes, and understanding experimental data. The techniques presented take advantage of 32 bit floating point texture capabilities to obtain validated solutions to the radiative transport equation for X-rays. An unsorted hexahedron projection algorithm is presented for curvilinear hexahedra that produces simulated radiographs in the absorption-only regime. A sorted tetrahedral projection algorithm is presented that simulates radiographs of emissive materials. We apply the tetrahedral projection algorithm to the simulation of experimental diagnostics for inertial confinement fusion experiments on a laser at the University of Rochester. We show that the hardware accelerated solution is faster than the current technique used by scientists.

  8. Adaptive control for accelerators

    DOEpatents

    Eaton, Lawrie E.; Jachim, Stephen P.; Natter, Eckard F.

    1991-01-01

    An adaptive feedforward control loop is provided to stabilize accelerator beam loading of the radio frequency field in an accelerator cavity during successive pulses of the beam into the cavity. A digital signal processor enables an adaptive algorithm to generate a feedforward error correcting signal functionally determined by the feedback error obtained by a beam pulse loading the cavity after the previous correcting signal was applied to the cavity. Each cavity feedforward correcting signal is successively stored in the digital processor and modified by the feedback error resulting from its application to generate the next feedforward error correcting signal. A feedforward error correcting signal is generated by the digital processor in advance of the beam pulse to enable a composite correcting signal and the beam pulse to arrive concurrently at the cavity.

  9. Pulsed electromagnetic gas acceleration

    NASA Technical Reports Server (NTRS)

    Jahn, R. G.; Vonjaskowsky, W. F.; Clark, K. E.

    1971-01-01

    Experimental data were combined with one-dimensional conservation relations to yield information on the energy deposition ratio in a parallel-plate accelerator, where the downstream flow was confined to a constant area channel. Approximately 70% of the total input power was detected in the exhaust flow, of which only about 20% appeared as directed kinetic energy, thus implying that a downstream expansion to convert chamber enthalpy into kinetic energy must be an important aspect of conventional high power MPD arcs. Spectroscopic experiments on a quasi-steady MPD argon accelerator verified the presence of A(III) and the absence of A(I), and indicated an azimuthal structure in the jet related to the mass injection locations. Measurements of pressure in the arc chamber and impact pressure in the exhaust jet using a piezocrystal backed by a Plexiglas rod were in good agreement with the electromagnetic thrust model.

  10. Pulsed Drift Tube Accelerator

    SciTech Connect

    Faltens, A.

    2004-10-25

    The pulsed drift-tube accelerator (DTA) concept was revived by Joe Kwan and John Staples and is being considered for the HEDP/WDM application. It could be used to reach the full energy or as an intermediate accelerator between the diode and a high gradient accelerator such as multi-beam r.f. In the earliest LBNL HIF proposals and conceptual drivers it was used as an extended injector to reach energies where an induction linac with magnetic quadrupoles is the best choice. For HEDP, because of the very short pulse duration, the DTA could provide an acceleration rate of about 1MV/m. This note is divided into two parts: the first, a design based on existing experience; the second, an optimistic extrapolation. The first accelerates 16 parallel K{sup +} beams at a constant line charge density of 0.25{micro} C/m per beam to 10 MeV; the second uses a stripper and charge selector at around 4MeV followed by further acceleration to reach 40 MeV. Both benefit from more compact sources than the present 2MV injector source, although that beam is the basis of the first design and is a viable option. A pulsed drift-tube accelerator was the first major HIF experiment at LBNL. It was designed to produce a 2{micro}s rectangular 1 Ampere C{sub s}{sup +} beam at 2MeV. It ran comfortably at 1.6MeV for several years, then at lower voltages and currents for other experiments, and remnants of that experiment are in use in present experiments, still running 25 years later. The 1A current, completely equivalent to 1.8A K{sup +}, was chosen to be intermediate between the beamlets appropriate for a multi-beam accelerator, and a single beam of, say, 10A, at injection energies. The original driver scenarios using one large beam on each side of the reactor rapidly fell out of favor because of the very high transverse and longitudinal fields from the beam space charge, circa 1MV/cm and 250 kV/cm respectively, near the chamber and because of aberrations in focusing a large diameter beam down to a 1

  11. SUPERDIFFUSIVE SHOCK ACCELERATION

    SciTech Connect

    Perri, S.; Zimbardo, G.

    2012-05-10

    The theory of diffusive shock acceleration is extended to the case of superdiffusive transport, i.e., when the mean square deviation grows proportionally to t{sup {alpha}}, with {alpha} > 1. Superdiffusion can be described by a statistical process called Levy random walk, in which the propagator is not a Gaussian but it exhibits power-law tails. By using the propagator appropriate for Levy random walk, it is found that the indices of energy spectra of particles are harder than those obtained where a normal diffusion is envisaged, with the spectral index decreasing with the increase of {alpha}. A new scaling for the acceleration time is also found, allowing substantially shorter times than in the case of normal diffusion. Within this framework we can explain a number of observations of flat spectra in various astrophysical and heliospheric contexts, for instance, for the Crab Nebula and the termination shock of the solar wind.

  12. Accelerators for Cancer Therapy

    DOE R&D Accomplishments Database

    Lennox, Arlene J.

    2000-05-30

    The vast majority of radiation treatments for cancerous tumors are given using electron linacs that provide both electrons and photons at several energies. Design and construction of these linacs are based on mature technology that is rapidly becoming more and more standardized and sophisticated. The use of hadrons such as neutrons, protons, alphas, or carbon, oxygen and neon ions is relatively new. Accelerators for hadron therapy are far from standardized, but the use of hadron therapy as an alternative to conventional radiation has led to significant improvements and refinements in conventional treatment techniques. This paper presents the rationale for radiation therapy, describes the accelerators used in conventional and hadron therapy, and outlines the issues that must still be resolved in the emerging field of hadron therapy.

  13. Advanced Accelerator Concepts: Seventh Workshop. Proceedings

    SciTech Connect

    Chattopadhyay, S.; McCullough, J.; Dahl, P.

    1997-09-01

    These proceedings are based on the Seventh Workshop on Advanced Accelerator Concepts held in October, 1996 at Lake Tahoe, California. This workshop was sponsored by the US Department of Energy(High Energy Physics Division, Advanced Technology Branch) and by the center for Beam Physics at the Lawrence Berkeley National Laboratory of the University of California. A wide range of applications was covered at the workshop, from high energy colliders to synchrotron radiation sources. This scope included topics such as new methods of particle acceleration, production of ultrahigh gradient electromagnetic fields, diagnostics and control of particle/photon beams in ultrashort dimensions and ultrafast time scales, and various energy and beam sources. There were 87 papers presented at the workshop and out of these, 65 have been abstracted for the Energy Science and Technology database.(AIP)

  14. Observation of particle acceleration in laboratory magnetosphere

    SciTech Connect

    Kawazura, Y.; Yoshida, Z.; Nishiura, M.; Saitoh, H.; Yano, Y.; Nogami, T.; Sato, N.; Yamasaki, M.; Kashyap, A.; Mushiake, T.

    2015-11-15

    The self-organization of magnetospheric plasma is brought about by inward diffusion of magnetized particles. Not only creating a density gradient toward the center of a dipole magnetic field, the inward diffusion also accelerates particles and provides a planetary radiation belt with high energy particles. Here, we report the first experimental observation of a “laboratory radiation belt” created in the ring trap 1 device. By spectroscopic measurement, we found an appreciable anisotropy in the ion temperature, proving the betatron acceleration mechanism which heats particles in the perpendicular direction with respect to the magnetic field when particles move inward. The energy balance model, including the heating mechanism, explains the observed ion temperature profile.

  15. Analysis of acceleration signals using wavelet transform.

    PubMed

    Sekine, M; Tamura, T; Akay, M; Togawa, T; Fukui, Y

    2000-06-01

    In this study, we attempted to discriminate the acceleration signal for horizontal level and stairway walking using wavelet-based fractal analysis method. The acceleration signal was measured close to the center of gravity of the body, while the subjects walked continuously in the corridor and up and down the stairs. We used the wavelet-based fractal analysis method to discriminate walking pattern. The parameter H which is related directly to the fractal dimension was estimated by the wavelet coefficient and was changed into low value during walking upstairs. By manually setting the threshold level for individual, it was possible to discriminate walking upstairs from the other walking type. However, the common feature among subjects was not shown between level walking and walking downstairs.

  16. Accelerated plate tectonics.

    PubMed

    Anderson, D L

    1975-03-21

    The concept of a stressed elastic lithospheric plate riding on a viscous asthenosphere is used to calculate the recurrence interval of great earthquakes at convergent plate boundaries, the separation of decoupling and lithospheric earthquakes, and the migration pattern of large earthquakes along an arc. It is proposed that plate motions accelerate after great decoupling earthquakes and that most of the observed plate motions occur during short periods of time, separated by periods of relative quiescence.

  17. Linear induction accelerator

    DOEpatents

    Buttram, M.T.; Ginn, J.W.

    1988-06-21

    A linear induction accelerator includes a plurality of adder cavities arranged in a series and provided in a structure which is evacuated so that a vacuum inductance is provided between each adder cavity and the structure. An energy storage system for the adder cavities includes a pulsed current source and a respective plurality of bipolar converting networks connected thereto. The bipolar high-voltage, high-repetition-rate square pulse train sets and resets the cavities. 4 figs.

  18. Compact pulsed accelerator

    SciTech Connect

    Rhee, M.J.; Schneider, R.F.

    1983-01-01

    The formation of fast pulses from a current charged transmission line and opening switch is described. By employing a plasma focus as an opening switch and diode in the prototype device, a proton beam of peak energy 250 keV is produced. The time integrated energy spectrum of the beam is constructed from a Thomson spectrograph. Applications of this device as an inexpensive and portable charged particle accelerator are discussed. 7 refs., 5 figs., 1 tab.

  19. ION ACCELERATION SYSTEM

    DOEpatents

    Luce, J.S.; Martin, J.A.

    1960-02-23

    Well focused, intense ion beams are obtained by providing a multi- apertured source grid in front of an ion source chamber and an accelerating multi- apertured grid closely spaced from and in alignment with the source grid. The longest dimensions of the elongated apertures in the grids are normal to the direction of the magnetic field used with the device. Large ion currents may be withdrawn from the source, since they do not pass through any small focal region between the grids.

  20. Frontiers of accelerator instrumentation

    SciTech Connect

    Ross, M.

    1992-08-01

    New technology has permitted significant performance improvements of established instrumentation techniques including beam position and profile monitoring. Fundamentally new profile monitor strategies are required for the next generation of accelerators, especially linear colliders (LC). Beams in these machines may be three orders of magnitude smaller than typical beams in present colliders. In this paper we review both the present performance levels achieved by conventional systems and present some new ideas for future colliders.

  1. Accelerator simulation using computers

    SciTech Connect

    Lee, M.; Zambre, Y.; Corbett, W.

    1992-01-01

    Every accelerator or storage ring system consists of a charged particle beam propagating through a beam line. Although a number of computer programs exits that simulate the propagation of a beam in a given beam line, only a few provide the capabilities for designing, commissioning and operating the beam line. This paper shows how a multi-track'' simulation and analysis code can be used for these applications.

  2. Accelerator simulation using computers

    SciTech Connect

    Lee, M.; Zambre, Y.; Corbett, W.

    1992-01-01

    Every accelerator or storage ring system consists of a charged particle beam propagating through a beam line. Although a number of computer programs exits that simulate the propagation of a beam in a given beam line, only a few provide the capabilities for designing, commissioning and operating the beam line. This paper shows how a ``multi-track`` simulation and analysis code can be used for these applications.

  3. Report on accelerated corrosion studies.

    SciTech Connect

    Mowry, Curtis Dale; Glass, Sarah Jill; Sorensen, Neil Robert

    2011-03-01

    Sandia National Laboratories (SNL) conducted accelerated atmospheric corrosion testing for the U.S. Consumer Product Safety Commission (CPSC) to help further the understanding of the development of corrosion products on conductor materials in household electrical components exposed to environmental conditions representative of homes constructed with problem drywall. The conditions of the accelerated testing were chosen to produce corrosion product growth that would be consistent with long-term exposure to environments containing humidity and parts per billion (ppb) levels of hydrogen sulfide (H{sub 2}S) that are thought to have been the source of corrosion in electrical components from affected homes. This report documents the test set-up, monitoring of electrical performance of powered electrical components during the exposure, and the materials characterization conducted on wires, screws, and contact plates from selected electrical components. No degradation in electrical performance (measured via voltage drop) was measured during the course of the 8-week exposure, which was approximately equivalent to 40 years of exposure in a light industrial environment. Analyses show that corrosion products consisting of various phases of copper sulfide, copper sulfate, and copper oxide are found on exposed surfaces of the conductor materials including wires, screws, and contact plates. The morphology and the thickness of the corrosion products showed a range of character. In some of the copper wires that were observed, corrosion product had flaked or spalled off the surface, exposing fresh metal to the reaction with the contaminant gasses; however, there was no significant change in the wire cross-sectional area.

  4. Projectile Combustion Effects on Ram Accelerator Performance

    NASA Astrophysics Data System (ADS)

    Chitale, Saarth Anjali

    University of Washington Abstract Projectile Combustion Effects on Ram Accelerator Performance Saarth Anjali Chitale Chair of the Supervisory Committee: Prof. Carl Knowlen William E. Boeing Department of Aeronautics and Astronautics The ram accelerator facility at the University of Washington is used to propel projectiles at supersonic velocities. This concept is similar to an air-breathing ramjet engine in that sub-caliber projectiles, shaped like the ramjet engine center-body, are shot through smooth-bore steel-walled tubes having an internal diameter of 38 mm. The ram accelerator propulsive cycles operate between Mach 2 to 10 and have the potential to accelerate projectile to velocities greater than 8 km/s. The theoretical thrust versus Mach number characteristics can be obtained using knowledge of gas dynamics and thermodynamics that goes into the design of the ram accelerator. The corresponding velocity versus distance profiles obtained from the test runs at the University of Washington, however, are often not consistent with the theoretical predictions after the projectiles reach in-tube Mach numbers greater than 4. The experimental velocities are typically greater than the expected theoretical predictions; which has led to the proposition that the combustion process may be moving up onto the projectile. An alternative explanation for higher than predicted thrust, which is explored here, is that the performance differences can be attributed to the ablation of the projectile body which results in molten metal being added to the flow of the gaseous combustible mixture around the projectile. This molten metal is assumed to mix uniformly and react with the gaseous propellant; thereby enhancing the propellant energy release and altering the predicted thrust-Mach characteristics. This theory predicts at what Mach number the projectile will first experience enhanced thrust and the corresponding velocity-distance profile. Preliminary results are in good agreement

  5. Accelerated Profile HMM Searches.

    PubMed

    Eddy, Sean R

    2011-10-01

    Profile hidden Markov models (profile HMMs) and probabilistic inference methods have made important contributions to the theory of sequence database homology search. However, practical use of profile HMM methods has been hindered by the computational expense of existing software implementations. Here I describe an acceleration heuristic for profile HMMs, the "multiple segment Viterbi" (MSV) algorithm. The MSV algorithm computes an optimal sum of multiple ungapped local alignment segments using a striped vector-parallel approach previously described for fast Smith/Waterman alignment. MSV scores follow the same statistical distribution as gapped optimal local alignment scores, allowing rapid evaluation of significance of an MSV score and thus facilitating its use as a heuristic filter. I also describe a 20-fold acceleration of the standard profile HMM Forward/Backward algorithms using a method I call "sparse rescaling". These methods are assembled in a pipeline in which high-scoring MSV hits are passed on for reanalysis with the full HMM Forward/Backward algorithm. This accelerated pipeline is implemented in the freely available HMMER3 software package. Performance benchmarks show that the use of the heuristic MSV filter sacrifices negligible sensitivity compared to unaccelerated profile HMM searches. HMMER3 is substantially more sensitive and 100- to 1000-fold faster than HMMER2. HMMER3 is now about as fast as BLAST for protein searches.

  6. Acceleration during magnetic reconnection

    SciTech Connect

    Beresnyak, Andrey; Li, Hui

    2015-07-16

    The presentation begins with colorful depictions of solar x-ray flares and references to pulsar phenomena. Plasma reconnection is complex, could be x-point dominated or turbulent, field lines could break due to either resistivity or non-ideal effects, such as electron pressure anisotropy. Electron acceleration is sometimes observed, and sometimes not. One way to study this complex problem is to have many examples of the process (reconnection) and compare them; the other way is to simplify and come to something robust. Ideal MHD (E=0) turbulence driven by magnetic energy is assumed, and the first-order acceleration is sought. It is found that dissipation in big (length >100 ion skin depths) current sheets is universal and independent on microscopic resistivity and the mean imposed field; particles are regularly accelerated while experiencing curvature drift in flows driven by magnetic tension. One example of such flow is spontaneous reconnection. This explains hot electrons with a power-law tail in solar flares, as well as ultrashort time variability in some astrophysical sources.

  7. Accelerator mass spectrometry.

    PubMed

    Hellborg, Ragnar; Skog, Göran

    2008-01-01

    In this overview the technique of accelerator mass spectrometry (AMS) and its use are described. AMS is a highly sensitive method of counting atoms. It is used to detect very low concentrations of natural isotopic abundances (typically in the range between 10(-12) and 10(-16)) of both radionuclides and stable nuclides. The main advantages of AMS compared to conventional radiometric methods are the use of smaller samples (mg and even sub-mg size) and shorter measuring times (less than 1 hr). The equipment used for AMS is almost exclusively based on the electrostatic tandem accelerator, although some of the newest systems are based on a slightly different principle. Dedicated accelerators as well as older "nuclear physics machines" can be found in the 80 or so AMS laboratories in existence today. The most widely used isotope studied with AMS is 14C. Besides radiocarbon dating this isotope is used in climate studies, biomedicine applications and many other fields. More than 100,000 14C samples are measured per year. Other isotopes studied include 10Be, 26Al, 36Cl, 41Ca, 59Ni, 129I, U, and Pu. Although these measurements are important, the number of samples of these other isotopes measured each year is estimated to be less than 10% of the number of 14C samples.

  8. Electrostatic Plasma Accelerator (EPA)

    NASA Technical Reports Server (NTRS)

    Brophy, John R.; Aston, Graeme

    1995-01-01

    The application of electric propulsion to communications satellites, however, has been limited to the use of hydrazine thrusters with electric heaters for thrust and specific impulse augmentation. These electrothermal thrusters operate at specific impulse levels of approximately 300 s with heater powers of about 500 W. Low power arcjets (1-3 kW) are currently being investigated as a way to increase specific impulse levels to approximately 500 s. Ion propulsion systems can easily produce specific impulses of 3000 s or greater, but have yet to be applied to communications satellites. The reasons most often given for not using ion propulsion systems are their high level of overall complexity, low thrust with long burn times, and the difficulty of integrating the propulsion system into existing commercial spacecraft busses. The Electrostatic Plasma Accelerator (EPA) is a thruster concept which promises specific impulse levels between low power arcjets and those of the ion engine while retaining the relative simplicity of the arcjet. The EPA thruster produces thrust through the electrostatic acceleration of a moderately dense plasma. No accelerating electrodes are used and the specific impulse is a direct function of the applied discharge voltage and the propellant atomic mass.

  9. ACCELERATION INTEGRATING MEANS

    DOEpatents

    Wilkes, D.F.

    1961-08-29

    An acceleration responsive device is described. A housing has at one end normally open electrical contacts and contains a piston system with a first part of non-magnetic material having metering orifices in the side walls for forming an air bearing between it and the walls of the housing; this first piston part is normally held against the other end of the housing from the noted contacts by a second piston or reset part. The reset part is of partly magnetic material, is separable from the flrst piston part, and is positioned within the housing intermediate the contacts and the first piston part. A magnet carried by the housing imposes a retaining force upon the reset part, along with a helical compression spring that is between the reset part and the end with the contacts. When a predetermined acceleration level is attained, the reset part overcomes the bias or retaining force provided by the magnet and the spring'' snaps'' into a depression in the housing adjacent the contacts. The first piston part is then free to move toward the contacts with its movement responsive tc acceleration forces and the metering orifices. (AEC)

  10. French nuclear physics accelerator opens

    NASA Astrophysics Data System (ADS)

    Dumé, Belle

    2016-12-01

    A new €140m particle accelerator for nuclear physics located at the French Large Heavy Ion National Accelerator (GANIL) in Caen was inaugurated last month in a ceremony attended by French president François Hollande.

  11. Gait analysis using gravitational acceleration measured by wearable sensors.

    PubMed

    Takeda, Ryo; Tadano, Shigeru; Todoh, Masahiro; Morikawa, Manabu; Nakayasu, Minoru; Yoshinari, Satoshi

    2009-02-09

    A novel method for measuring human gait posture using wearable sensor units is proposed. The sensor units consist of a tri-axial acceleration sensor and three gyro sensors aligned on three axes. The acceleration and angular velocity during walking were measured with seven sensor units worn on the abdomen and the lower limb segments (both thighs, shanks and feet). The three-dimensional positions of each joint are calculated from each segment length and joint angle. Joint angle can be estimated mechanically from the gravitational acceleration along the anterior axis of the segment. However, the acceleration data during walking includes three major components; translational acceleration, gravitational acceleration and external noise. Therefore, an optimization analysis was represented to separate only the gravitational acceleration from the acceleration data. Because the cyclic patterns of acceleration data can be found during constant walking, a FFT analysis was applied to obtain some characteristic frequencies in it. A pattern of gravitational acceleration was assumed using some parts of these characteristic frequencies. Every joint position was calculated from the pattern under the condition of physiological motion range of each joint. An optimized pattern of the gravitational acceleration was selected as a solution of an inverse problem. Gaits of three healthy volunteers were measured by walking for 20s on a flat floor. As a result, the acceleration data of every segment was measured simultaneously. The characteristic three-dimensional walking could be shown by the expression using a stick figure model. In addition, the trajectories of the knee joint in the horizontal plane could be checked by visual imaging on a PC. Therefore, this method provides important quantitive information for gait diagnosis.

  12. Suprathermal Charged Particle Acceleration by Small-scale Flux Ropes.

    NASA Astrophysics Data System (ADS)

    Zank, G. P.; le Roux, J. A.; Webb, G. M.

    2015-12-01

    We consider different limits of our recently developed kinetic transport theory to investigate the potential of super-Alvenic solar wind regions containing several small-scale flux ropes to explain the acceleration of suprathermal ions to power-law spectra as observations show. Particle acceleration is modeled in response to flux-rope activity involving contraction, merging (reconnection), and collisions in the limit where the particle gyoradius is smaller than the characteristic flux-rope scale length. The emphasis is mainly on the statistical variance in the electric fields induced by flux-rope dynamics rather than on the mean electric field induced by multiple flux ropes whose acceleration effects are discussed elsewhere. Our steady-state analytical solutions suggest that particle drift acceleration by flux ropes, irrespective of whether displaying incompressible or compressible behavior, can yield power laws asymptotically at higher energies whereas an exponential spectral rollover results asymptotically when field-aligned guiding center motion acceleration occur by reconnection electric fields from merging flux ropes. This implies that at sufficiently high particle energies, drift acceleration might dominate. We also expect compressive flux ropes to yield harder power-law spectra than incompressible flux ropes. Preliminary results will be discussed to illustrate how particle acceleration might be affected when both diffusive shock and small-scale flux acceleration occur simultaneously at interplanetary shocks.

  13. Effect of gasoline octane quality on vehicle acceleration performance

    SciTech Connect

    Not Available

    1991-07-01

    A study was conducted under the auspices of the Coordinating Research Council, Inc. (CRC) to assess the potential effects of gasoline octane quality on vehicle acceleration performance. Twelve participating laboratories, representing both the oil and the automotive industries, tested a total of 182 vehicles as part of the 1989 CRC Octane Number Requirement Survey. The vehicles consisted of 78 with electronic knock control systems and 104 without. All testing was performed using the 1989/1990 CRC FBRU fuel series. The results showed that acceleration performance of vehicles with knock sensors was significantly affected by gasoline octane quality. Octane effects on acceleration performance were most pronounced at maximum-throttle (detent) conditions and at octane levels below the vehicles' octane requirements; however, some knock-sensor vehicles did show improved acceleration performance with fuels at octane levels above the octane number requirement. Acceleration performance in non-knock sensor vehicles was unaffected by octane quality.

  14. Mississippi Technology Transfer Center

    NASA Technical Reports Server (NTRS)

    1987-01-01

    The Mississippi Technology Transfer Center at the John C. Stennis Space Center in Hancock County, Miss., was officially dedicated in 1987. The center is home to several state agencies as well as the Center For Higher Learning.

  15. Plasma accelerator experiments in Yugoslavia

    NASA Astrophysics Data System (ADS)

    Purić, J.; Astashynski, V. M.; Kuraica, M. M.; Dojčinovié, I. P.

    2002-12-01

    An overview is given of the results obtained in the Plasma Accelerator Experiments in Belgrade, using quasi-stationary high current plasma accelerators constructed within the framework of the Yugoslavia-Belarus Joint Project. So far, the following plasma accelerators have been realized: Magnetoplasma Compressor type (MPC); MPC Yu type; one stage Erosive Plasma Dynamic System (EPDS) and, in final stage of construction two stage Quasi-Stationary High Current Plasma Accelerator (QHPA).

  16. Science and Technology of Accelerators

    NASA Astrophysics Data System (ADS)

    Valerio Lizarraga, Cristhian; Castilla Loaeza, Alejandro; Guillermo Cantón, Gerardo; Duarte, Carlos; Chavez Valenzuela, Daniel; Hernández Chahín, Karim; Cuna, Humberto Maury; Medina Medrano, Luis; Reyes Herrera, Juan; Sosa Güitrón, Salvador; Valdivia García, Alan; Rendón, Bruce Yee

    2016-10-01

    The Mexican Particle Accelerator Community (CMAP) was created in 2015 and currently its members participate in different experiments around the world. Using their expertise, they are working in the development of the particle accelerators area in Mexico. This paper provides a summary of the research done by its members and presents the preliminary design of an electron linear particle accelerator (eLINAC). This proposal will be the first accelerator designed and created in Mexico.

  17. Joint Center for Artificial Photosynthesis

    ScienceCinema

    Koval, Carl; Lee, Kenny; Houle, Frances; Lewis, Nate

    2016-07-12

    The Joint Center for Artificial Photosynthesis (JCAP) is the nation's largest research program dedicated to the development of an artificial solar-fuel generation technology. Established in 2010 as a U.S. Department of Energy (DOE) Energy Innovation Hub, JCAP aims to find a cost-effective method to produce fuels using only sunlight, water, and carbon dioxide as inputs. JCAP brings together more than 140 top scientists and researchers from the California Institute of Technology and its lead partner, Berkeley Lab, along with collaborators from the SLAC National Accelerator Laboratory, and the University of California campuses at Irvine and San Diego.

  18. Joint Center for Artificial Photosynthesis

    SciTech Connect

    Koval, Carl; Lee, Kenny; Houle, Frances; Lewis, Nate

    2013-12-10

    The Joint Center for Artificial Photosynthesis (JCAP) is the nation's largest research program dedicated to the development of an artificial solar-fuel generation technology. Established in 2010 as a U.S. Department of Energy (DOE) Energy Innovation Hub, JCAP aims to find a cost-effective method to produce fuels using only sunlight, water, and carbon dioxide as inputs. JCAP brings together more than 140 top scientists and researchers from the California Institute of Technology and its lead partner, Berkeley Lab, along with collaborators from the SLAC National Accelerator Laboratory, and the University of California campuses at Irvine and San Diego.

  19. Accelerator Science: Proton vs. Electron

    ScienceCinema

    Lincoln, Don

    2016-10-19

    Particle accelerators are one of the most powerful ways to study the fundamental laws that govern the universe. However, there are many design considerations that go into selecting and building a particular accelerator. In this video, Fermilab’s Dr. Don Lincoln explains the pros and cons of building an accelerator that collides pairs of protons to one that collides electrons.

  20. Accelerator Science: Circular vs. Linear

    ScienceCinema

    Lincoln, Don

    2016-12-14

    Particle accelerator are scientific instruments that allow scientists to collide particles together at incredible energies to study the secrets of the universe. However, there are many manners in which particle accelerators can be constructed. In this video, Fermilab’s Dr. Don Lincoln explains the pros and cons of circular and linear accelerators.

  1. Accelerator Science: Circular vs. Linear

    SciTech Connect

    Lincoln, Don

    2016-11-10

    Particle accelerator are scientific instruments that allow scientists to collide particles together at incredible energies to study the secrets of the universe. However, there are many manners in which particle accelerators can be constructed. In this video, Fermilab’s Dr. Don Lincoln explains the pros and cons of circular and linear accelerators.

  2. Accelerator Science: Proton vs. Electron

    SciTech Connect

    Lincoln, Don

    2016-10-11

    Particle accelerators are one of the most powerful ways to study the fundamental laws that govern the universe. However, there are many design considerations that go into selecting and building a particular accelerator. In this video, Fermilab’s Dr. Don Lincoln explains the pros and cons of building an accelerator that collides pairs of protons to one that collides electrons.

  3. Center for Beam Physics: 1994--95

    SciTech Connect

    1995-05-01

    The Center for Beam Physics is a multidisciplinary research and development unit in the Accelerator and Fusion Research Division at the Lawrence Berkeley Laboratory of the University of California. At the heart of the Center`s mission is a fundamental quest for mechanisms of acceleration, radiation, transport, and focusing of energy and information. Dedicated to exploring the frontiers of particle and photon beam physics, its primary mission is to promote the science and technology of the production, manipulation, storage, and control of systems of charged particles and photons. This roster and annual report provides a glimpse of the scientists, engineers, technical support, students, and administrative staff that make up the CBP`s team and gives a brief review of the multifaceted activities during 1994 and 1995.

  4. Accelerate Climate Models with the IBM Cell Processor

    NASA Astrophysics Data System (ADS)

    Zhou, S.; Duffy, D.; Clune, T.; Williams, S.; Suarez, M.; Halem, M.

    2008-12-01

    Ever increasing model resolutions and physical processes in climate models demand continual computing power increases. The IBM Cell processor's order-of- magnitude peak performance increase over conventional processors makes it very attractive for fulfilling this requirement. However, the Cell's characteristics: 256KB local memory per SPE and the new low-level communication mechanism, make it very challenging to port an application. We selected the solar radiation component of the NASA GEOS-5 climate model, which: (1) is representative of column physics components (~50% total computation time), (2) has a high computational load relative to data traffic to/from main memory, and (3) performs independent calculations across multiple columns. We converted the baseline code (single-precision, Fortran code) to C and ported it to an IBM BladeCenter QS20, manually SIMDizing 4 independent columns, and found that a Cell with 8 SPEs can process more than 3000 columns per second. Compared with the baseline results, the Cell is ~6.76x, ~8.91x, ~9.85x faster than a core on Intel's Xeon Woodcrest, Dempsey, and Itanium2 respectively. Our analysis shows that the Cell could also speed up the dynamics component (~25% total computation time). We believe this dramatic performance improvement makes the Cell processor very competitive, at least as an accelerator. We will report our experience in porting both the C and Fortran codes and will discuss our work in porting other climate model components.

  5. Integrating functional genomics to accelerate mechanistic personalized medicine

    PubMed Central

    Tyner, Jeffrey W.

    2017-01-01

    The advent of deep sequencing technologies has resulted in the deciphering of tremendous amounts of genetic information. These data have led to major discoveries, and many anecdotes now exist of individual patients whose clinical outcomes have benefited from novel, genetically guided therapeutic strategies. However, the majority of genetic events in cancer are currently undrugged, leading to a biological gap between understanding of tumor genetic etiology and translation to improved clinical approaches. Functional screening has made tremendous strides in recent years with the development of new experimental approaches to studying ex vivo and in vivo drug sensitivity. Numerous discoveries and anecdotes also exist for translation of functional screening into novel clinical strategies; however, the current clinical application of functional screening remains largely confined to small clinical trials at specific academic centers. The intersection between genomic and functional approaches represents an ideal modality to accelerate our understanding of drug sensitivities as they relate to specific genetic events and further understand the full mechanisms underlying drug sensitivity patterns. PMID:28299357

  6. Integrating functional genomics to accelerate mechanistic personalized medicine.

    PubMed

    Tyner, Jeffrey W

    2017-03-01

    The advent of deep sequencing technologies has resulted in the deciphering of tremendous amounts of genetic information. These data have led to major discoveries, and many anecdotes now exist of individual patients whose clinical outcomes have benefited from novel, genetically guided therapeutic strategies. However, the majority of genetic events in cancer are currently undrugged, leading to a biological gap between understanding of tumor genetic etiology and translation to improved clinical approaches. Functional screening has made tremendous strides in recent years with the development of new experimental approaches to studying ex vivo and in vivo drug sensitivity. Numerous discoveries and anecdotes also exist for translation of functional screening into novel clinical strategies; however, the current clinical application of functional screening remains largely confined to small clinical trials at specific academic centers. The intersection between genomic and functional approaches represents an ideal modality to accelerate our understanding of drug sensitivities as they relate to specific genetic events and further understand the full mechanisms underlying drug sensitivity patterns.

  7. A HIGH REPETITION PLASMA MIRROR FOR STAGED ELECTRON ACCELERATION

    SciTech Connect

    Sokollik, Thomas; Shiraishi, Satomi; Osterhoff, Jens; Evans, Eugene; Gonsalves, Anthony; Nakamura, Kei; vanTilborg, Jeroen; Lin, Chen; Toth, Csaba; Leemans, Wim

    2011-07-22

    In order to build a compact, staged laser plasma accelerator the in-coupling of the laser beam to the different stages represents one of the key issues. To limit the spatial foot print and thus to realize a high overall acceleration gradient, a concept has to be found which realizes this in-coupling within a few centimeters. We present experiments on a tape-drive based plasma mirror which could be used to reflect the focused laser beam into the acceleration stage.

  8. 42 CFR 405.910 - Appointed representatives.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... the party and the appointed representative. (2) To initiate an appeal within the 1-year time frame... representative. (j) Effect of notice or request to an appointed representative. A notice or request sent to the appointed representative has the same force and effect as if was sent to the party. (k)...

  9. Very fast kicker for accelerator applications

    SciTech Connect

    Grishanov, B.I.; Podgorny, F.V.; Ruemmler, J.; Shiltsev, V.D.

    1996-11-01

    We describe a very fast counter traveling wave kicker with a full pulse width of about 7 ns. Successful test experiment has been done with hi-tech semiconductor technology FET pulse generator with a MHz- range repetition rates and maximum kick strength of the order of 3 G{center_dot}m. Further. increase of the strength seems to be quite possible with the FET pursers, that makes the kicker to be very useful tool for bunch-by-bunch injection/extraction and other accelerator applications.

  10. The long-term acceleration of waste glass corrosion: A preliminary review

    SciTech Connect

    Kielpinski, A.L.

    1995-07-01

    Whereas a prior conception of glass dissolution assumed a relatively rapid initial dissolution which then slowed to a smaller, fairly constant longer-term rate, some recent work suggests that these two stages are followed by a third phase of dissolution, in which the dissolution rate is accelerated with respect to what had previously been thought of as the final long-term rate. The goals of the present study are to compile experimental data which may have a bearing on this phenomena, and to provide an initial assessment of these data. The Savannah River Technology Center (SRTC) is contracted to develop glass formulation models for vitrification of Hanford low-level waste (LLW), in support of the Hanford Tank Waste Remediation System Technology Development Program. The phenomenon of an increase in corrosion rate, following a period characterized by a low corrosion rate, has been observed by a number of researchers on a number of waste glass compositions. Despite inherent ambiguities arising from SA/V (glass surface area to solution volume ratio) and other effects, valid comparisons can be made in which accelerated corrosion was observed in one test, but not in another. Some glass compositions do not appear to attain a plateau region; it may be that the observation of continued, non-negligible corrosion in these glasses represents a passage from the initial rate to the accelerated rate. The long-term corrosion is a function of the interaction between the glass and its environment, including the leaching solution and the surrounding materials. Reaction path modeling and stability field considerations have been used with some success to predict the changes in corrosion rate over time, due to these interactions. The accelerated corrosion phenomenon highlights the need for such integrated corrosion modeling and the scenario-specific nature of a particular glass composition`s durability.

  11. Using Corrosion Design Models to Accelerate the Transition of Alternatives

    DTIC Science & Technology

    2012-08-01

    Corrosion Design Models • All moving to incorporate light metals, composites and other aviation materials • Maturation includes effect of...Using Corrosion Design Models to Accelerate the Transition of Alternatives Craig Matzdorf Materials Engineering Division Naval Air...TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Naval Air Warfare Center, Materials Engineering Division,22347

  12. APT accelerator. Topical report

    SciTech Connect

    Lawrence, G.; Rusthoi, D.

    1995-03-01

    The Accelerator Production of Tritium (APT) project, sponsored by Department of Energy Defense Programs (DOE/DP), involves the preconceptual design of an accelerator system to produce tritium for the nation`s stockpile of nuclear weapons. Tritium is an isotope of hydrogen used in nuclear weapons, and must be replenished because of radioactive decay (its half-life is approximately 12 years). Because the annual production requirements for tritium has greatly decreased since the end of the Cold War, an alternative approach to reactors for tritium production, based on a linear accelerator, is now being seriously considered. The annual tritium requirement at the time this study was undertaken (1992-1993) was 3/8 that of the 1988 goal, usually stated as 3/8-Goal. Continued reduction in the number of weapons in the stockpile has led to a revised (lower) production requirement today (March, 1995). The production requirement needed to maintain the reduced stockpile, as stated in the recent Nuclear Posture Review (summer 1994) is approximately 3/16-Goal, half the previous level. The Nuclear Posture Review also requires that the production plant be designed to accomodate a production increase (surge) to 3/8-Goal capability within five years, to allow recovery from a possible extended outage of the tritium plant. A multi-laboratory team, collaborating with several industrial partners, has developed a preconceptual APT design for the 3/8-Goal, operating at 75% capacity. The team has presented APT as a promising alternative to the reactor concepts proposed for Complex-21. Given the requirements of a reduced weapons stockpile, APT offers both significant safety, environmental, and production-fexibility advantages in comparison with reactor systems, and the prospect of successful development in time to meet the US defense requirements of the 21st Century.

  13. Recent Advances in Plasma Acceleration

    SciTech Connect

    Hogan, Mark

    2007-03-19

    The costs and the time scales of colliders intended to reach the energy frontier are such that it is important to explore new methods of accelerating particles to high energies. Plasma-based accelerators are particularly attractive because they are capable of producing accelerating fields that are orders of magnitude larger than those used in conventional colliders. In these accelerators a drive beam, either laser or particle, produces a plasma wave (wakefield) that accelerates charged particles. The ultimate utility of plasma accelerators will depend on sustaining ultra-high accelerating fields over a substantial length to achieve a significant energy gain. More than 42 GeV energy gain was achieved in an 85 cm long plasma wakefield accelerator driven by a 42 GeV electron drive beam in the Final Focus Test Beam (FFTB) Facility at SLAC. Most of the beam electrons lose energy to the plasma wave, but some electrons in the back of the same beam pulse are accelerated with a field of {approx}52 GV/m. This effectively doubles their energy, producing the energy gain of the 3 km long SLAC accelerator in less than a meter for a small fraction of the electrons in the injected bunch. Prospects for a drive-witness bunch configuration and high-gradient positron acceleration experiments planned for the SABER facility will be discussed.

  14. A National Network of Neurotechnology Centers for the BRAIN Initiative

    PubMed Central

    Alivisatos, A. Paul; Chun, Miyoung; Church, George M.; Greenspan, Ralph J.; Roukes, Michael L.; Yuste, Rafael

    2017-01-01

    We propose the creation of a national network of neurotechnology centers to enhance and accelerate the BRAIN Initiative and optimally leverage the effort and creativity of individual laboratories involved in it. As “brain observatories,” these centers could provide the critical interdisciplinary environment both for realizing ambitious and complex technologies and for providing individual investigators with access to them. PMID:26481036

  15. A National Network of Neurotechnology Centers for the BRAIN Initiative.

    PubMed

    Alivisatos, A Paul; Chun, Miyoung; Church, George M; Greenspan, Ralph J; Roukes, Michael L; Yuste, Rafael

    2015-11-04

    We propose the creation of a national network of neurotechnology centers to enhance and accelerate the BRAIN Initiative and optimally leverage the effort and creativity of individual laboratories involved in it. As "brain observatories," these centers could provide the critical interdisciplinary environment both for realizing ambitious and complex technologies and for providing individual investigators with access to them.

  16. Accelerating Gallstone Dissolution

    PubMed Central

    Tao, J. C.; Cussler, E. L.; Evans, D. F.

    1974-01-01

    The dissolution rates of cholesterol in model bile salt solutions are controlled by diffusion in slowly flowing bile and by interfacial kinetics in rapidly flowing bile. At low flow, dissolution varies with the square root of bile flow and can be predicted, a priori, from existing correlations of mass transfer. At high bile flow, dissolution is independent of bile flow and is probably dominated by the rate of micelle adsorption. These results show that cholesterol gallstone dissolution, a potential nonsurgical therapy for cholelithiasis, can be accelerated little in slow bile, but more significantly in rapidly flowing bile. PMID:4530271

  17. The Accelerating Universe

    NASA Astrophysics Data System (ADS)

    Schmidt, Brian P.

    2012-05-01

    In 1998 two teams traced back the expansion of the universe over billions of years and discovered that it was accelerating, a startling discovery that suggests that more than 70% of the cosmos is contained in a previously unknown form of matter, called Dark Energy. The 2011 Nobel Laureate for Physics, Brian Schmidt, leader of the High-Redshift Supernova Search Team, will describe this discovery and explain how astronomers have used observations to trace our universe's history back more than 13 billion years, leading them to ponder the ultimate fate of the cosmos.

  18. Ultra-accelerated natural sunlight exposure testing

    DOEpatents

    Jorgensen, Gary J.; Bingham, Carl; Goggin, Rita; Lewandowski, Allan A.; Netter, Judy C.

    2000-06-13

    Process and apparatus for providing ultra accelerated natural sunlight exposure testing of samples under controlled weathering without introducing unrealistic failure mechanisms in exposed materials and without breaking reciprocity relationships between flux exposure levels and cumulative dose that includes multiple concurrent levels of temperature and relative humidity at high levels of natural sunlight comprising: a) concentrating solar flux uniformly; b) directing the controlled uniform sunlight onto sample materials in a chamber enclosing multiple concurrent levels of temperature and relative humidity to allow the sample materials to be subjected to accelerated irradiance exposure factors for a sufficient period of time in days to provide a corresponding time of about at least a years worth of representative weathering of the sample materials.

  19. IDEA Clean Energy Application Center

    SciTech Connect

    Thornton, Robert

    2013-09-30

    The DOE Clean Energy Application Centers were launched with a goal of focusing on important aspects of our nation’s energy supply including Efficiency, Reliability and Resiliency. Clean Energy solutions based on Combined Heat & Power (CHP), District Energy and Waste Heat Recovery are at the core of ensuring a reliable and efficient energy infrastructure for campuses, communities, and industry and public enterprises across the country. IDEA members which include colleges and universities, hospitals, airports, downtown utilities as well as manufacturers, suppliers and service providers have long-standing expertise in the planning, design, construction and operations of Clean Energy systems. They represent an established base of successful projects and systems at scale and serve important and critical energy loads. They also offer experience, lessons learned and best practices which are of immense value to the sustained growth of the Clean Energy sector. IDEA has been able to leverage the funds from the project award to raise the visibility, improve the understanding and increase deployment CHP, District Energy and Waste Heat Recovery solutions across the regions of our nation, in collaboration with the regional CEAC’s. On August 30, 2012, President Obama signed an Executive Order to accelerate investments in industrial energy efficiency (EE), including CHP and set a national goal of 40 GW of new CHP installation over the next decade IDEA is pleased to have been able to support this Executive Order in a variety of ways including raising awareness of the goal through educational workshops and Conferences and recognizing the installation of large scale CHP and district energy systems A supporting key area of collaboration has involved IDEA providing technical assistance on District Energy/CHP project screenings and feasibility to the CEAC’s for multi building, multi-use projects. The award was instrumental in the development of a first-order screening

  20. COMPUTATIONAL SCIENCE CENTER

    SciTech Connect

    DAVENPORT, J.

    2006-11-01

    Computational Science is an integral component of Brookhaven's multi science mission, and is a reflection of the increased role of computation across all of science. Brookhaven currently has major efforts in data storage and analysis for the Relativistic Heavy Ion Collider (RHIC) and the ATLAS detector at CERN, and in quantum chromodynamics. The Laboratory is host for the QCDOC machines (quantum chromodynamics on a chip), 10 teraflop/s computers which boast 12,288 processors each. There are two here, one for the Riken/BNL Research Center and the other supported by DOE for the US Lattice Gauge Community and other scientific users. A 100 teraflop/s supercomputer will be installed at Brookhaven in the coming year, managed jointly by Brookhaven and Stony Brook, and funded by a grant from New York State. This machine will be used for computational science across Brookhaven's entire research program, and also by researchers at Stony Brook and across New York State. With Stony Brook, Brookhaven has formed the New York Center for Computational Science (NYCCS) as a focal point for interdisciplinary computational science, which is closely linked to Brookhaven's Computational Science Center (CSC). The CSC has established a strong program in computational science, with an emphasis on nanoscale electronic structure and molecular dynamics, accelerator design, computational fluid dynamics, medical imaging, parallel computing and numerical algorithms. We have been an active participant in DOES SciDAC program (Scientific Discovery through Advanced Computing). We are also planning a major expansion in computational biology in keeping with Laboratory initiatives. Additional laboratory initiatives with a dependence on a high level of computation include the development of hydrodynamics models for the interpretation of RHIC data, computational models for the atmospheric transport of aerosols, and models for combustion and for energy utilization. The CSC was formed to bring together

  1. Proceedings of a workshop on Applications of Accelerators

    SciTech Connect

    Herrmannsfeldt, W.B.; Sessler, A.M.; Alonso, J.R.

    1994-01-31

    This document is a compilation of material collected as the results of a workshop, Applications of Accelerators, held at the Stanford Linear Accelerator Center, 1--2 December 1993. The material collected here has been edited for style and to minimize duplication. Footnotes will identify the original source of the material. We believe that the reader will find that this document has something for every interest. There are applications in the fields of health, food preservation, energy, environmental monitoring and protection, and industrial processing. Man y of the examples discussed have already passed the demonstration stage. Most of the others are the subject of active accelerator research. Taken as a whole, the particle accelerator field contains a wealth of application opportunities, some already in use, and many more ready to be exploited.

  2. Solvent-free cleaning using a centrifugal cryogenic pellet accelerator

    SciTech Connect

    Haines, J.R.; Fisher, P.W.; Foster, C.A.

    1995-06-01

    An advanced centrifuge that accelerates frozen CO{sub 2} pellets to high speeds for surface cleaning and paint removal is being developed at the Oak Ridge National Laboratory. The centrifuge-based accelerator was designed, fabricated, and tested under a program sponsored by the Warner Robins Air Logistics Center, Robins Air Force Base, Georgia. In comparison to the more conventional compressed air ``sandblast`` pellet accelerators, the centrifugal accelerator system can achieve higher pellet speeds, has precise speed control, and is more than ten times as energy efficient. Furthermore, the use of frozen CO{sub 2} pellets instead of conventional metal, plastic, sand, or other abrasive materials that remain solid at room temperature, minimizes the waste stream. This apparatus has been used to demonstrate cleaning of various surfaces, including removal of paint, oxide coatings, metal coatings, organic coatings, and oil and grease coatings from a variety of surfaces. The design and operation of the apparatus is discussed.

  3. The gravitational acceleration of antimatter

    SciTech Connect

    Holzscheiter, M.H.

    1994-06-01

    We have proposed measuring the acceleration of antiprotons in the Earth`s gravitational field by launching antiprotons from a thermal distribution at 4 K upwards against the force of gravity and measuring their time-of-flight (TOF). The TOF distribution thus obtained will exhibit a cut-off representing the minimum kinetic energy necessary to reach the detector at the top of the experiment. The cut-off time is independent of the inertial mass of the particles and is a direct measure of g for the particles studied. We propose to compare the cut-off time, and thereby g, of negative hydrogen ions and antiprotons. The single most difficult problem to be solved for this method consists of shielding all stray-electric fields to a level where the force of gravity is dominating force acting on the particle. Alternative methods for reducing the effect of stray-electric fields are discussed and a brief analysis of experimental possibilities using neutral antihydrogen atoms is presented.

  4. Development of High-Gradient Dielectric Laser-Driven Particle Accelerator Structures

    SciTech Connect

    Byer, Robert L.

    2013-11-07

    The thrust of Stanford's program is to conduct research on high-gradient dielectric accelerator structures driven with high repetition-rate, tabletop infrared lasers. The close collaboration between Stanford and SLAC (Stanford Linear Accelerator Center) is critical to the success of this project, because it provides a unique environment where prototype dielectric accelerator structures can be rapidly fabricated and tested with a relativistic electron beam.

  5. Acceleration in Linear and Circular Motion

    ERIC Educational Resources Information Center

    Kellington, S. H.; Docherty, W.

    1975-01-01

    Describes the construction of a simple accelerometer and explains its use in demonstrating acceleration, deceleration, constant speed, measurement of acceleration, acceleration and the inclined plane and angular and radial acceleration. (GS)

  6. AT2 DS II - Accelerator System Design (Part II) - CCC Video Conference

    SciTech Connect

    2010-12-17

    Discussion Session - Accelerator System Design (Part II) Tutors: C. Darve, J. Weisend II, Ph. Lebrun, A. Dabrowski, U. Raich Video Conference with the CERN Control Center. Experts in the field of Accelerator science will be available to answer the students questions. This session will link the CCC and SA (using Codec VC).

  7. AT2 DS II - Accelerator System Design (Part II) - CCC Video Conference

    ScienceCinema

    None

    2016-07-12

    Discussion Session - Accelerator System Design (Part II) Tutors: C. Darve, J. Weisend II, Ph. Lebrun, A. Dabrowski, U. Raich Video Conference with the CERN Control Center. Experts in the field of Accelerator science will be available to answer the students questions. This session will link the CCC and SA (using Codec VC).

  8. Timescale Correlation between Marine Atmospheric Exposure and Accelerated Corrosion Testing

    NASA Technical Reports Server (NTRS)

    Montgomery, Eliza L.; Calle, Luz Marina; Curran, Jerone C.; Kolody, Mark R.

    2011-01-01

    Evaluation of metal-based structures has long relied on atmospheric exposure test sites to determine corrosion resistance in marine environments. Traditional accelerated corrosion testing relies on mimicking the exposure conditions, often incorporating salt spray and ultraviolet (UV) radiation, and exposing the metal to continuous or cyclic conditions of the corrosive environment. Their success for correlation to atmospheric exposure is often a concern when determining the timescale to which the accelerated tests can be related. Accelerated laboratory testing, which often focuses on the electrochemical reactions that occur during corrosion conditions, has yet to be universally accepted as a useful tool in predicting the long term service life of a metal despite its ability to rapidly induce corrosion. Although visual and mass loss methods of evaluating corrosion are the standard and their use is imperative, a method that correlates timescales from atmospheric exposure to accelerated testing would be very valuable. This work uses surface chemistry to interpret the chemical changes occurring on low carbon steel during atmospheric and accelerated corrosion conditions with the objective of finding a correlation between its accelerated and long-term corrosion performance. The current results of correlating data from marine atmospheric exposure conditions at the Kennedy Space Center beachside corrosion test site, alternating seawater spray, and immersion in typical electrochemical laboratory conditions, will be presented. Key words: atmospheric exposure, accelerated corrosion testing, alternating seawater spray, marine, correlation, seawater, carbon steel, long-term corrosion performance prediction, X-ray photoelectron spectroscopy.

  9. Mechanical power output during running accelerations in wild turkeys.

    PubMed

    Roberts, Thomas J; Scales, Jeffrey A

    2002-05-01

    We tested the hypothesis that the hindlimb muscles of wild turkeys (Meleagris gallopavo) can produce maximal power during running accelerations. The mechanical power developed during single running steps was calculated from force-plate and high-speed video measurements as turkeys accelerated over a trackway. Steady-speed running steps and accelerations were compared to determine how turkeys alter their running mechanics from a low-power to a high-power gait. During maximal accelerations, turkeys eliminated two features of running mechanics that are characteristic of steady-speed running: (i) they produced purely propulsive horizontal ground reaction forces, with no braking forces, and (ii) they produced purely positive work during stance, with no decrease in the mechanical energy of the body during the step. The braking and propulsive forces ordinarily developed during steady-speed running are important for balance because they align the ground reaction force vector with the center of mass. Increases in acceleration in turkeys correlated with decreases in the angle of limb protraction at toe-down and increases in the angle of limb retraction at toe-off. These kinematic changes allow turkeys to maintain the alignment of the center of mass and ground reaction force vector during accelerations when large propulsive forces result in a forward-directed ground reaction force. During the highest accelerations, turkeys produced exclusively positive mechanical power. The measured power output during acceleration divided by the total hindlimb muscle mass yielded estimates of peak instantaneous power output in excess of 400 W kg(-1) hindlimb muscle mass. This value exceeds estimates of peak instantaneous power output of turkey muscle fibers. The mean power developed during the entire stance phase increased from approximately zero during steady-speed runs to more than 150 W kg(-1) muscle during the highest accelerations. The high power outputs observed during accelerations

  10. Adaptive and accelerated tracking-learning-detection

    NASA Astrophysics Data System (ADS)

    Guo, Pengyu; Li, Xin; Ding, Shaowen; Tian, Zunhua; Zhang, Xiaohu

    2013-08-01

    An improved online long-term visual tracking algorithm, named adaptive and accelerated TLD (AA-TLD) based on Tracking-Learning-Detection (TLD) which is a novel tracking framework has been introduced in this paper. The improvement focuses on two aspects, one is adaption, which makes the algorithm not dependent on the pre-defined scanning grids by online generating scale space, and the other is efficiency, which uses not only algorithm-level acceleration like scale prediction that employs auto-regression and moving average (ARMA) model to learn the object motion to lessen the detector's searching range and the fixed number of positive and negative samples that ensures a constant retrieving time, but also CPU and GPU parallel technology to achieve hardware acceleration. In addition, in order to obtain a better effect, some TLD's details are redesigned, which uses a weight including both normalized correlation coefficient and scale size to integrate results, and adjusts distance metric thresholds online. A contrastive experiment on success rate, center location error and execution time, is carried out to show a performance and efficiency upgrade over state-of-the-art TLD with partial TLD datasets and Shenzhou IX return capsule image sequences. The algorithm can be used in the field of video surveillance to meet the need of real-time video tracking.

  11. Utilizing GPUs to Accelerate Turbomachinery CFD Codes

    NASA Technical Reports Server (NTRS)

    MacCalla, Weylin; Kulkarni, Sameer

    2016-01-01

    GPU computing has established itself as a way to accelerate parallel codes in the high performance computing world. This work focuses on speeding up APNASA, a legacy CFD code used at NASA Glenn Research Center, while also drawing conclusions about the nature of GPU computing and the requirements to make GPGPU worthwhile on legacy codes. Rewriting and restructuring of the source code was avoided to limit the introduction of new bugs. The code was profiled and investigated for parallelization potential, then OpenACC directives were used to indicate parallel parts of the code. The use of OpenACC directives was not able to reduce the runtime of APNASA on either the NVIDIA Tesla discrete graphics card, or the AMD accelerated processing unit. Additionally, it was found that in order to justify the use of GPGPU, the amount of parallel work being done within a kernel would have to greatly exceed the work being done by any one portion of the APNASA code. It was determined that in order for an application like APNASA to be accelerated on the GPU, it should not be modular in nature, and the parallel portions of the code must contain a large portion of the code's computation time.

  12. Simulations for Plasma and Laser Acceleration

    NASA Astrophysics Data System (ADS)

    Vay, Jean-Luc; Lehe, Rémi

    Computer simulations have had a profound impact on the design and understanding of past and present plasma acceleration experiments, and will be a key component for turning plasma accelerators from a promising technology into a mainstream scientific tool. In this article, we present an overview of the numerical techniques used with the most popular approaches to model plasma-based accelerators: electromagnetic particle-in-cell, quasistatic and ponderomotive guiding center. The material that is presented is intended to serve as an introduction to the basics of those approaches, and to advances (some of them very recent) that have pushed the state of the art, such as the optimal Lorentz-boosted frame, advanced laser envelope solvers and the elimination of numerical Cherenkov instability. The particle-in-cell method, which has broader interest and is more standardized, is presented in more depth. Additional topics that are cross-cutting, such as azimuthal Fourier decomposition or filtering, are also discussed, as well as potential challenges and remedies in the initialization of simulations and output of data. Examples of simulations using the techniques that are presented have been left out of this article for conciseness, and because simulation results are best understood when presented together, and contrasted with theoretical and/or experimental results, as in other articles of this volume.

  13. Charged spinning black holes as accelerators of spinning particles

    NASA Astrophysics Data System (ADS)

    Zhang, Yu-Peng; Gu, Bao-Min; Wei, Shao-Wen; Yang, Jie; Liu, Yu-Xiao

    2016-12-01

    It is well known that some black holes can act as accelerators for particles without spin. Recently, some works have considered the collision of two spinning particles in the background of Schwarzschild and Kerr black holes and it has been shown that the center-of-mass energy of the test particles is related to the spin. In this paper we extend the results to some more general cases. We consider Kerr-Newman black holes as accelerators for spinning particles. We derive the center-of-mass energy of the spinning particles and use numerical method to investigate how the center-of-mass energy is affected by the properties of the black holes and spinning particles.

  14. Space Acceleration Measurement System (SAMS)/Orbital Acceleration Research Experiment (OARE)

    NASA Technical Reports Server (NTRS)

    Hakimzadeh, Roshanak

    1998-01-01

    The Life and Microgravity Spacelab (LMS) payload flew on the Orbiter Columbia on mission STS-78 from June 20th to July 7th, 1996. The LMS payload on STS-78 was dedicated to life sciences and microgravity experiments. Two accelerometer systems managed by the NASA Lewis Research Center (LERC) flew to support these experiments, namely the Orbital Acceleration Research Experiment (OARE) and the Space Acceleration Measurements System (SAMS). In addition, the Microgravity Measurement Assembly (NOAA), managed by the European Space Research and Technology Center (ESA/ESTEC), and sponsored by NASA, collected acceleration data in support of the experiments on-board the LMS mission. OARE downlinked real-time quasi-steady acceleration data, which was provided to the investigators. The SAMS recorded higher frequency data on-board for post-mission analysis. The MMA downlinked real-time quasi-steady as well as higher frequency acceleration data, which was provided to the investigators. The Principal Investigator Microgravity Services (PIMS) project at NASA LERC supports principal investigators of microgravity experiments as they evaluate the effects of varying acceleration levels on their experiments. A summary report was prepared by PIMS to furnish interested experiment investigators with a guide to evaluate the acceleration environment during STS-78, and as a means of identifying areas which require further study. The summary report provides an overview of the STS-78 mission, describes the accelerometer systems flown on this mission, discusses some specific analyses of the accelerometer data in relation to the various activities which occurred during the mission, and presents plots resulting from these analyses as a snapshot of the environment during the mission. Numerous activities occurred during the STS-78 mission that are of interest to the low-gravity community. Specific activities of interest during this mission were crew exercise, radiator deployment, Vernier Reaction

  15. Radiosurgery with a linear accelerator. Methodological aspects.

    PubMed

    Betti, O O; Galmarini, D; Derechinsky, V

    1991-01-01

    Based on the concepts of Leksell and on recommendations of different Swedish physicists on the use of linear accelerator for radiosurgical use, we developed a new methodology coupling the Talairach stereotactic system with a commercial linac. Anatomical facts encouraged us to use coronal angles of irradiation employing the angular displacement of the linac above the horizontal plane. Different coronal planes are obtained by rotation of the stereotactic frame. The center of the irradiated target coincides with the irradiation and rotation center of the linear accelerator. Multiple targets can be irradiated in the same session. We use as recommended a secondary collimator in heavy alloy. Special software was prepared after different dosimetric controls. The use of a PC allows us to employ 1-6 targets and different collimators to displace the isocenters in order to obtain geometrical isodose modification, and to change the value of each irradiation arc or portions of each arc in some minutes. Simple or sophisticated neurosurgical strategies can be applied in the treatment of frequently irregular shape and volume AVMs.

  16. Ion Accelerator With Negatively Biased Decelerator Grid

    NASA Technical Reports Server (NTRS)

    Brophy, John R.

    1994-01-01

    Three-grid ion accelerator in which accelerator grid is biased at negative potential and decelerator grid downstream of accelerator grid biased at smaller negative potential. This grid and bias arrangement reduces frequency of impacts, upon accelerator grid, of charge-exchange ions produced downstream in collisions between accelerated ions and atoms and molecules of background gas. Sputter erosion of accelerator grid reduced.

  17. 50 CFR 1.2 - Authorized representative.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR GENERAL PROVISIONS DEFINITIONS § 1.2 Authorized representative. Authorized representative means the subordinate... matters. The Director, U.S. Fish and Wildlife Service is frequently the authorized representative of...

  18. 29 CFR 1201.6 - Representatives.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 4 2012-07-01 2012-07-01 false Representatives. 1201.6 Section 1201.6 Labor Regulations Relating to Labor (Continued) NATIONAL MEDIATION BOARD DEFINITIONS § 1201.6 Representatives. The term representative means any person or persons, labor union, organization, or corporation designated either by...

  19. 29 CFR 1201.6 - Representatives.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 4 2014-07-01 2014-07-01 false Representatives. 1201.6 Section 1201.6 Labor Regulations Relating to Labor (Continued) NATIONAL MEDIATION BOARD DEFINITIONS § 1201.6 Representatives. The term representative means any person or persons, labor union, organization, or corporation designated either by...

  20. 29 CFR 1201.6 - Representatives.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 4 2010-07-01 2010-07-01 false Representatives. 1201.6 Section 1201.6 Labor Regulations Relating to Labor (Continued) NATIONAL MEDIATION BOARD DEFINITIONS § 1201.6 Representatives. The term representative means any person or persons, labor union, organization, or corporation designated either by...

  1. 29 CFR 1201.6 - Representatives.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 4 2013-07-01 2013-07-01 false Representatives. 1201.6 Section 1201.6 Labor Regulations Relating to Labor (Continued) NATIONAL MEDIATION BOARD DEFINITIONS § 1201.6 Representatives. The term representative means any person or persons, labor union, organization, or corporation designated either by...

  2. 29 CFR 1201.6 - Representatives.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 4 2011-07-01 2011-07-01 false Representatives. 1201.6 Section 1201.6 Labor Regulations Relating to Labor (Continued) NATIONAL MEDIATION BOARD DEFINITIONS § 1201.6 Representatives. The term representative means any person or persons, labor union, organization, or corporation designated either by...

  3. 45 CFR 2400.11 - Faculty representatives.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Faculty representatives. 2400.11 Section 2400.11... FOUNDATION FELLOWSHIP PROGRAM REQUIREMENTS Application § 2400.11 Faculty representatives. Each college and university that chooses to do so may annually appoint or reappoint a faculty representative who will be...

  4. Advanced Accelerators for Medical Applications

    NASA Astrophysics Data System (ADS)

    Uesaka, Mitsuru; Koyama, Kazuyoshi

    We review advanced accelerators for medical applications with respect to the following key technologies: (i) higher RF electron linear accelerator (hereafter “linac”); (ii) optimization of alignment for the proton linac, cyclotron and synchrotron; (iii) superconducting magnet; (iv) laser technology. Advanced accelerators for medical applications are categorized into two groups. The first group consists of compact medical linacs with high RF, cyclotrons and synchrotrons downsized by optimization of alignment and superconducting magnets. The second group comprises laser-based acceleration systems aimed of medical applications in the future. Laser plasma electron/ion accelerating systems for cancer therapy and laser dielectric accelerating systems for radiation biology are mentioned. Since the second group has important potential for a compact system, the current status of the established energy and intensity and of the required stability are given.

  5. Accelerator simulation of astrophysical processes

    NASA Technical Reports Server (NTRS)

    Tombrello, T. A.

    1983-01-01

    Phenomena that involve accelerated ions in stellar processes that can be simulated with laboratory accelerators are described. Stellar evolutionary phases, such as the CNO cycle, have been partially explored with accelerators, up to the consumption of He by alpha particle radiative capture reactions. Further experimentation is indicated on reactions featuring N-13(p,gamma)O-14, O-15(alpha, gamma)Ne-19, and O-14(alpha,p)F-17. Accelerated beams interacting with thin foils produce reaction products that permit a determination of possible elemental abundances in stellar objects. Additionally, isotopic ratios observed in chondrites can be duplicated with accelerator beam interactions and thus constraints can be set on the conditions producing the meteorites. Data from isotopic fractionation from sputtering, i.e., blasting surface atoms from a material using a low energy ion beam, leads to possible models for processes occurring in supernova explosions. Finally, molecules can be synthesized with accelerators and compared with spectroscopic observations of stellar winds.

  6. Laser acceleration and its future

    PubMed Central

    Tajima, Toshiki

    2010-01-01

    Laser acceleration is based on the concept to marshal collective fields that may be induced by laser. In order to exceed the material breakdown field by a large factor, we employ the broken-down matter of plasma. While the generated wakefields resemble with the fields in conventional accelerators in their structure (at least qualitatively), it is their extreme accelerating fields that distinguish the laser wakefield from others, amounting to tiny emittance and compact accelerator. The current research largely falls on how to master the control of acceleration process in spatial and temporal scales several orders of magnitude smaller than the conventional method. The efforts over the last several years have come to a fruition of generating good beam properties with GeV energies on a table top, leading to many applications, such as ultrafast radiolysis, intraoperative radiation therapy, injection to X-ray free electron laser, and a candidate for future high energy accelerators. PMID:20228616

  7. Accelerating Spectrum Sharing Technologies

    SciTech Connect

    Juan D. Deaton; Lynda L. Brighton; Rangam Subramanian; Hussein Moradi; Jose Loera

    2013-09-01

    Spectrum sharing potentially holds the promise of solving the emerging spectrum crisis. However, technology innovators face the conundrum of developing spectrum sharing technologies without the ability to experiment and test with real incumbent systems. Interference with operational incumbents can prevent critical services, and the cost of deploying and operating an incumbent system can be prohibitive. Thus, the lack of incumbent systems and frequency authorization for technology incubation and demonstration has stymied spectrum sharing research. To this end, industry, academia, and regulators all require a test facility for validating hypotheses and demonstrating functionality without affecting operational incumbent systems. This article proposes a four-phase program supported by our spectrum accountability architecture. We propose that our comprehensive experimentation and testing approach for technology incubation and demonstration will accelerate the development of spectrum sharing technologies.

  8. Accelerated Decay of Radioisotopes

    DTIC Science & Technology

    2013-01-01

    00-01 -2013 Technical June20 l l-June 2012 4 . TITLE AND SUBTITLE Sa. CONTRACT NUMBER DTRA MIPR 11-2362M Accelerated Decay of Radioisotopes Sb...268 x E +2 4.788 026 x E -2 6.894 757 4.535 924 x E -1 4.214 011 x E -2 1.601 846 x E +1 1.000 000 x E -2 2.579 760 x E - 4 1.000 000 x E -8...c a y o f R a d i o i s o t o p e s " P r o p o s a l # B R C A L L 0 7 - N - 2 - 0 0 4 7 I l l u s t r a t i o n o f \\ P F R P a s p o

  9. Understanding projectile acceleration.

    PubMed

    Hecht, H; Bertamini, M

    2000-04-01

    Throwing and catching balls or other objects is a generally highly practiced skill; however, conceptual as well as perceptual understanding of the mechanics that underlie this skill is surprisingly poor. In 5 experiments, we investigated conceptual and perceptual understanding of simple ballistic motion. Paper-and-pencil tests revealed that up to half of all participants mistakenly believed that a ball would continue to accelerate after it left the thrower's hand. Observers also showed a remarkable tolerance for anomalous trajectory shapes. Perceptual judgments based on graphics animations replicated these erroneous beliefs for shallow release angles. Observers' tolerance for anomalies tended to decrease with their distance from the actor. The findings are at odds with claims of the naive physics literature that liken intuitive understanding to Aristotelian or medieval physics theories. Instead, observers seem to project their intentions to the ball itself (externalization) or even feel that they have power over the ball when it is still close.

  10. Pulsed Plasma Accelerator Modeling

    NASA Technical Reports Server (NTRS)

    Goodman, M.; Kazeminezhad, F.; Owens, T.

    2009-01-01

    This report presents the main results of the modeling task of the PPA project. The objective of this task is to make major progress towards developing a new computational tool with new capabilities for simulating cylindrically symmetric 2.5 dimensional (2.5 D) PPA's. This tool may be used for designing, optimizing, and understanding the operation of PPA s and other pulsed power devices. The foundation for this task is the 2-D, cylindrically symmetric, magnetohydrodynamic (MHD) code PCAPPS (Princeton Code for Advanced Plasma Propulsion Simulation). PCAPPS was originally developed by Sankaran (2001, 2005) to model Lithium Lorentz Force Accelerators (LLFA's), which are electrode based devices, and are typically operated in continuous magnetic field to the model, and implementing a first principles, self-consistent algorithm to couple the plasma and power circuit that drives the plasma dynamics.

  11. Pulsed electromagnetic acceleration

    NASA Technical Reports Server (NTRS)

    Jahn, R. G.; Vonjaskowsky, W. F.; Clark, K. E.

    1973-01-01

    Direct measurements of the power deposited in the anode of a multimegawatt MPD accelerator using thermocouples attached to a thin shell anode reveal a dramatic decrease in the fractional anode power from 50% at 200 KW input power to less than 10% at 20 MW power. The corresponding local power flux peak at a value of 10,000 W/sq cm at the lip of the anode exhaust orifice, a distribution traced to a corresponding peak in the local current density at the anode. A comparison of voltage-current characteristics and spectral photographs of the MPD discharge using quartz, boron nitride and plexiglas insulators with various mass injection configurations led to the identification of different voltage modes and regions of ablation free operation. The technique of piezoelectric impact pressure measurement in the MPD exhaust flow was refined to account for the effects due to probe yaw angle.

  12. Linac-accelerator-radiosurgery.

    PubMed

    Sturm, V; Schlegel, W; Pastyr, O; Treuer, H; Voges, J; Müller, R P; Lorenz, W J

    1993-01-01

    A survey is given of the actual possibilities and limitations of the use of linear accelerators (Linac radiosurgery systems) for intra = cranial radiosurgery. Depending on the collimator size, spherical fields from 5-54 mm in diameter can be irradiated with dose gradients from 10% (large fields) to 20% (small fields) per millimeter distance between surface and treatment volume. This is comparable to the possibilities of Gamma-Knife and Proton-irradiation. Optimal mechanical adjustment of gantry and linac table are necessary for the required stability of the isocenter. Mechanical inaccuracy should be smaller than 0.8 mm. Advanced computerized 3D-treatment planning systems are indispensable prerequisites for accurate treatment and use of the flexibility of the linac system. Future developments are outlined.

  13. Network acceleration techniques

    NASA Technical Reports Server (NTRS)

    Crowley, Patricia (Inventor); Awrach, James Michael (Inventor); Maccabe, Arthur Barney (Inventor)

    2012-01-01

    Splintered offloading techniques with receive batch processing are described for network acceleration. Such techniques offload specific functionality to a NIC while maintaining the bulk of the protocol processing in the host operating system ("OS"). The resulting protocol implementation allows the application to bypass the protocol processing of the received data. Such can be accomplished this by moving data from the NIC directly to the application through direct memory access ("DMA") and batch processing the receive headers in the host OS when the host OS is interrupted to perform other work. Batch processing receive headers allows the data path to be separated from the control path. Unlike operating system bypass, however, the operating system still fully manages the network resource and has relevant feedback about traffic and flows. Embodiments of the present disclosure can therefore address the challenges of networks with extreme bandwidth delay products (BWDP).

  14. Paraelectric gas flow accelerator

    NASA Technical Reports Server (NTRS)

    Sherman, Daniel M. (Inventor); Wilkinson, Stephen P. (Inventor); Roth, J. Reece (Inventor)

    2001-01-01

    A substrate is configured with first and second sets of electrodes, where the second set of electrodes is positioned asymmetrically between the first set of electrodes. When a RF voltage is applied to the electrodes sufficient to generate a discharge plasma (e.g., a one-atmosphere uniform glow discharge plasma) in the gas adjacent to the substrate, the asymmetry in the electrode configuration results in force being applied to the active species in the plasma and in turn to the neutral background gas. Depending on the relative orientation of the electrodes to the gas, the present invention can be used to accelerate or decelerate the gas. The present invention has many potential applications, including increasing or decreasing aerodynamic drag or turbulence, and controlling the flow of active and/or neutral species for such uses as flow separation, altering heat flow, plasma cleaning, sterilization, deposition, etching, or alteration in wettability, printability, and/or adhesion.

  15. Lectures in accelerator theory

    SciTech Connect

    Month, M

    1980-01-01

    Lecture I deals with the behavior of particles in the nonlinear field arising from the electromagnetic interaction of colliding beams. The case treated, that of counter-rotating proton beams crossing each other at a non-zero angle, has the simple feature that the force between the beam is one dimensional. In lecture II, an analysis of the development of traveling waves on particle beams is presented. The situation studied is that of a uniform beam current in a circular accelerator and the excitation for the coherent motion is induced by the resistivity of the vacuum chamber wall. Finally, in lecture III, a description of the current accumulation process used at the proton storage rings at CERN (The ISR) is given. Particle pulses of rather low average current are injected and stored along the length and width of the vacuum chamber. The efficiency is very high and large currents (over 40 amperes) have been achieved.

  16. HIGH ENERGY PARTICLE ACCELERATOR

    DOEpatents

    Courant, E.D.; Livingston, M.S.; Snyder, H.S.

    1959-04-14

    An improved apparatus is presented for focusing charged particles in an accelerator. In essence, the invention includes means for establishing a magnetic field in discrete sectors along the path of moving charged particles, the magnetic field varying in each sector in accordance with the relation. B = B/ sub 0/ STAln (r-r/sub 0/)/r/sub 0/!, where B/sub 0/ is the value of the magnetic field at the equilibrium orbit of radius r/sub 0/ of the path of the particles, B equals the magnetic field at the radius r of the chamber and n equals the magnetic field gradient index, the polarity of n being abruptly reversed a plurality of times as the particles travel along their arcuate path. With this arrangement, the particles are alternately converged towards the axis of their equillbrium orbit and diverged therefrom in successive sectors with a resultant focusing effect.

  17. Acceleration tests of a 3 GHz proton linear accelerator (LIBO) for hadrontherapy

    NASA Astrophysics Data System (ADS)

    De Martinis, C.; Giove, D.; Amaldi, U.; Berra, P.; Crandall, K.; Mauri, M.; Weiss, M.; Zennaro, R.; Rosso, E.; Szeless, B.; Vretenar, M.; Masullo, M. R.; Vaccaro, V.; Calabretta, L.; Rovelli, A.

    2012-07-01

    This paper describes the acceleration tests performed at the Catania LNS Laboratory on a 3 GHz linac module of the side coupled type, which boosts the proton energy of a beam extracted from a cyclotron from 62 to 72 MeV. The output proton energy was measured with two devices: a NaI(Tl) crystal and a bending magnet. The experimental spectra are in good agreement with the calculated ones. From their shape it is obtained that (18±3.0)% of the transmitted protons fall in a ±2 MeV interval centered around 72 MeV. This result is in good agreement with the 20% value derived from the simulation of the acceleration process. The measured energy of the accelerated protons was used to check that the shunt impedance of the structure is equal to the computed one within 3%. This was the first time that a 3 GHz structure has been used to accelerate protons, and the results of the tests have demonstrated that a high frequency linac can be used as a cyclotron booster.

  18. High-gradient compact linear accelerator

    DOEpatents

    Carder, Bruce M.

    1998-01-01

    A high-gradient linear accelerator comprises a solid-state stack in a vacuum of five sets of disc-shaped Blumlein modules each having a center hole through which particles are sequentially accelerated. Each Blumlein module is a sandwich of two outer conductive plates that bracket an inner conductive plate positioned between two dielectric plates with different thicknesses and dielectric constants. A third dielectric core in the shape of a hollow cylinder forms a casing down the series of center holes, and it has a dielectric constant different that the two dielectric plates that sandwich the inner conductive plate. In operation, all the inner conductive plates are charged to the same DC potential relative to the outer conductive plates. Next, all the inner conductive plates are simultaneously shorted to the outer conductive plates at the outer diameters. The signal short will propagate to the inner diameters at two different rates in each Blumlein module. A faster wave propagates quicker to the third dielectric core across the dielectric plates with the closer spacing and lower dielectric constant. When the faster wave reaches the inner extents of the outer and inner conductive plates, it reflects back outward and reverses the field in that segment of the dielectric core. All the field segments in the dielectric core are then in unipolar agreement until the slower wave finally propagates to the third dielectric core across the dielectric plates with the wider spacing and higher dielectric constant. During such unipolar agreement, particles in the core are accelerated with gradients that exceed twenty megavolts per meter.

  19. High-gradient compact linear accelerator

    DOEpatents

    Carder, B.M.

    1998-05-26

    A high-gradient linear accelerator comprises a solid-state stack in a vacuum of five sets of disc-shaped Blumlein modules each having a center hole through which particles are sequentially accelerated. Each Blumlein module is a sandwich of two outer conductive plates that bracket an inner conductive plate positioned between two dielectric plates with different thicknesses and dielectric constants. A third dielectric core in the shape of a hollow cylinder forms a casing down the series of center holes, and it has a dielectric constant different that the two dielectric plates that sandwich the inner conductive plate. In operation, all the inner conductive plates are charged to the same DC potential relative to the outer conductive plates. Next, all the inner conductive plates are simultaneously shorted to the outer conductive plates at the outer diameters. The signal short will propagate to the inner diameters at two different rates in each Blumlein module. A faster wave propagates quicker to the third dielectric core across the dielectric plates with the closer spacing and lower dielectric constant. When the faster wave reaches the inner extents of the outer and inner conductive plates, it reflects back outward and reverses the field in that segment of the dielectric core. All the field segments in the dielectric core are then in unipolar agreement until the slower wave finally propagates to the third dielectric core across the dielectric plates with the wider spacing and higher dielectric constant. During such unipolar agreement, particles in the core are accelerated with gradients that exceed twenty megavolts per meter. 10 figs.

  20. Naked singularities as particle accelerators. II

    SciTech Connect

    Patil, Mandar; Joshi, Pankaj S.; Malafarina, Daniele

    2011-03-15

    We generalize here our earlier results on particle acceleration by naked singularities. We showed recently [M. Patil and P. S. Joshi, Phys. Rev. D 82, 104049 (2010).] that the naked singularities that form due to the gravitational collapse of massive stars provide a suitable environment where particles could get accelerated and collide at arbitrarily high center-of-mass energies. However, we focused there only on the spherically symmetric gravitational collapse models, which were also assumed to be self-similar. In this paper, we broaden and generalize the result to all gravitational collapse models leading to the formation of a naked singularity as the final state of collapse, evolving from a regular initial data, without making any prior restrictive assumptions about the spacetime symmetries such as above. We show that, when the particles interact and collide near the Cauchy horizon, the energy of collision in the center-of-mass frame will be arbitrarily high, thus offering a window to the Planck scale physics. We also consider the issue of various possible physical mechanisms of generation of such very high-energy particles from the vicinity of naked singularity. We then construct a model of gravitational collapse to a timelike naked singularity to demonstrate the working of these ideas, where the pressure is allowed to be negative, but the energy conditions are respected. We show that a finite amount of mass-energy density has to be necessarily radiated away from the vicinity of the naked singularity as the collapse evolves. Therefore, the nature of naked singularities, both at the classical and quantum level, could play an important role in the process of particle acceleration, explaining the occurrence of highly energetic outgoing particles in the vicinity of the Cauchy horizon that participate in extreme high-energy collisions.

  1. High-gradient compact linear accelerator

    SciTech Connect

    Carder, B.M.

    1995-12-31

    A high-gradient linear accelerator comprises a solid-state stack in a vacuum of five sets of disc-shaped Blumlein modules each having a center hole through which particles are sequentially accelerated. Each Blumlein module is a sandwich of two outer conductive plates that bracket an inner conductive plate positioned between two dielectric plates with different thicknesses and dielectric constants. A third dielectric core in the shape of a hollow cylinder forms a casing down the series of center holes, and it has a dielectric constant different that the two dielectric plates that sandwich the inner conductive plate. In operation, all the inner conductive plates are charged to the same DC potential relative to the outer conductive plates. Next, all the inner conductive plates are simultaneously shorted to the outer conductive plates at the outer diameters. The signal short will propagate to the inner diameters at two different rates in each Blumlein module. A faster wave propagates quicker to the third dielectric core across the dielectric plates with the closer spacing and lower dielectric constant. When the faster wave reaches the inner extents of the outer and inner conductive plates, it reflects back outward and reverses the field in that segment of the dielectric core. All the field segments in the dielectric core are then in unipolar agreement until the slower wave finally propagates to the third dielectric core across the dielectric plates with the wider spacing and higher dielectric constant. During such unipolar agreement, particles in the core are accelerated with gradients that exceed twenty megavolts per meter.

  2. Cast dielectric composite linear accelerator

    DOEpatents

    Sanders, David M.; Sampayan, Stephen; Slenes, Kirk; Stoller, H. M.

    2009-11-10

    A linear accelerator having cast dielectric composite layers integrally formed with conductor electrodes in a solventless fabrication process, with the cast dielectric composite preferably having a nanoparticle filler in an organic polymer such as a thermosetting resin. By incorporating this cast dielectric composite the dielectric constant of critical insulating layers of the transmission lines of the accelerator are increased while simultaneously maintaining high dielectric strengths for the accelerator.

  3. NIIEFA accelerators for applied purposes

    NASA Astrophysics Data System (ADS)

    Vorogushin, M. F.; Strokach, A. P.; Filatov, O. G.

    2016-12-01

    Since the foundation of the institute, we have designed and delivered more than three hundred different accelerators to Russia and abroad: cyclotrons, linear accelerators, and neutron generators. The technical characteristics of our equipment makes it competitive on the international market. Here we present the application, main parameters, and status of accelerators manufactured by NIIEFA, as well as prospects for the development of electrophysical systems for applied purposes.

  4. Collective accelerator for electron colliders

    SciTech Connect

    Briggs, R.J.

    1985-05-13

    A recent concept for collective acceleration and focusing of a high energy electron bunch is discussed, in the context of its possible applicability to large linear colliders in the TeV range. The scheme can be considered to be a member of the general class of two-beam accelerators, where a high current, low voltage beam produces the acceleration fields for a trailing high energy bunch.

  5. Basic concepts in plasma accelerators.

    PubMed

    Bingham, Robert

    2006-03-15

    In this article, we present the underlying physics and the present status of high gradient and high-energy plasma accelerators. With the development of compact short pulse high-brightness lasers and electron and positron beams, new areas of studies for laser/particle beam-matter interactions is opening up. A number of methods are being pursued vigorously to achieve ultra-high-acceleration gradients. These include the plasma beat wave accelerator (PBWA) mechanism which uses conventional long pulse ( approximately 100 ps) modest intensity lasers (I approximately 10(14)-10(16) W cm(-2)), the laser wakefield accelerator (LWFA) which uses the new breed of compact high-brightness lasers (<1 ps) and intensities >10(18) W cm(-2), self-modulated laser wakefield accelerator (SMLWFA) concept which combines elements of stimulated Raman forward scattering (SRFS) and electron acceleration by nonlinear plasma waves excited by relativistic electron and positron bunches the plasma wakefield accelerator. In the ultra-high intensity regime, laser/particle beam-plasma interactions are highly nonlinear and relativistic, leading to new phenomenon such as the plasma wakefield excitation for particle acceleration, relativistic self-focusing and guiding of laser beams, high-harmonic generation, acceleration of electrons, positrons, protons and photons. Fields greater than 1 GV cm(-1) have been generated with monoenergetic particle beams accelerated to about 100 MeV in millimetre distances recorded. Plasma wakefields driven by both electron and positron beams at the Stanford linear accelerator centre (SLAC) facility have accelerated the tail of the beams.

  6. Understanding and Representing Natural Language Meaning.

    DTIC Science & Technology

    1982-05-01

    lobby waste basket of the crowded Pompidou Center in exchange for the girl. Asking that the police not intervene, Boullard arranged for the delivery of...perception," Tech. Rept3. 91 and 95, Center for Human Information Processing, USCD. Minsky, M. 1980. "K-lines: A theory of memory," C Sciencg, vol. 4, pp. 117

  7. Accelerated vaccine development against emerging infectious diseases.

    PubMed

    Leblanc, Pierre R; Yuan, Jianping; Brauns, Tim; Gelfand, Jeffrey A; Poznansky, Mark C

    2012-07-01

    Emerging and re-emerging infectious diseases represent a major challenge to vaccine development since it involves two seemingly contradictory requirements. Rapid and flexible vaccine generation while using technologies and processes that can facilitate accelerated regulatory review. Development in the "-omics" in combination with advances in vaccinology offer novel opportunities to meet these requirements. Here we describe how a consortium of five different organizations from academia and industry is addressing these challenges. This novel approach has the potential to become the new standard in vaccine development allowing timely deployment to avert potential pandemics.

  8. Children's cancer centers

    MedlinePlus

    Pediatric cancer center; Pediatric oncology center; Comprehensive cancer center ... Treating childhood cancer is not the same as treating adult cancer. The cancers are different. So are the treatments and the ...

  9. The Watergate Learning Center

    ERIC Educational Resources Information Center

    Training in Business and Industry, 1971

    1971-01-01

    The Watergate Learning Center, recently opened by Sterling Learning Center in Washington, D. C., blueprints the plan established by Sterling and Marriott Hotels for a national chain of learning centers with much the same facilities. (EB)

  10. Compact accelerator for medical therapy

    DOEpatents

    Caporaso, George J.; Chen, Yu-Jiuan; Hawkins, Steven A.; Sampayan, Stephen E.; Paul, Arthur C.

    2010-05-04

    A compact accelerator system having an integrated particle generator-linear accelerator with a compact, small-scale construction capable of producing an energetic (.about.70-250 MeV) proton beam or other nuclei and transporting the beam direction to a medical therapy patient without the need for bending magnets or other hardware often required for remote beam transport. The integrated particle generator-accelerator is actuable as a unitary body on a support structure to enable scanning of a particle beam by direction actuation of the particle generator-accelerator.

  11. Accelerator based epithermal neutron source

    NASA Astrophysics Data System (ADS)

    Taskaev, S. Yu.

    2015-11-01

    We review the current status of the development of accelerator sources of epithermal neutrons for boron neutron capture therapy (BNCT), a promising method of malignant tumor treatment. Particular attention is given to the source of epithermal neutrons on the basis of a new type of charged particle accelerator: tandem accelerator with vacuum insulation and lithium neutron-producing target. It is also shown that the accelerator with specialized targets makes it possible to generate fast and monoenergetic neutrons, resonance and monoenergetic gamma-rays, alpha-particles, and positrons.

  12. High field gradient particle accelerator

    DOEpatents

    Nation, John A.; Greenwald, Shlomo

    1989-01-01

    A high electric field gradient electron accelerator utilizing short duration, microwave radiation, and capable of operating at high field gradients for high energy physics applications or at reduced electric field gradients for high average current intermediate energy accelerator applications. Particles are accelerated in a smooth bore, periodic undulating waveguide, wherein the period is so selected that the particles slip an integral number of cycles of the r.f. wave every period of the structure. This phase step of the particles produces substantially continuous acceleration in a traveling wave without transverse magnetic or other guide means for the particle.

  13. High field gradient particle accelerator

    DOEpatents

    Nation, J.A.; Greenwald, S.

    1989-05-30

    A high electric field gradient electron accelerator utilizing short duration, microwave radiation, and capable of operating at high field gradients for high energy physics applications or at reduced electric field gradients for high average current intermediate energy accelerator applications is disclosed. Particles are accelerated in a smooth bore, periodic undulating waveguide, wherein the period is so selected that the particles slip an integral number of cycles of the r.f. wave every period of the structure. This phase step of the particles produces substantially continuous acceleration in a traveling wave without transverse magnetic or other guide means for the particle. 10 figs.

  14. Accelerators for research and applications

    SciTech Connect

    Alonso, J.R.

    1990-06-01

    The newest particle accelerators are almost always built for extending the frontiers of research, at the cutting edge of science and technology. Once these machines are operating and these technologies mature, new applications are always found, many of which touch our lives in profound ways. The evolution of accelerator technologies will be discussed, with descriptions of accelerator types and characteristics. The wide range of applications of accelerators will be discussed, in fields such as nuclear science, medicine, astrophysics and space-sciences, power generation, airport security, materials processing and microcircuit fabrication. 13 figs.

  15. ADS Based on Linear Accelerators

    NASA Astrophysics Data System (ADS)

    Pan, Weimin; Dai, Jianping

    An accelerator-driven system (ADS), which combines a particle accelerator with a subcritical core, is commonly regarded as a promising device for the transmutation of nuclear waste, as well as a potential scheme for thorium-based energy production. So far the predominant choice of the accelerator for ADS is a superconducting linear accelerator (linac). This article gives a brief overview of ADS based on linacs, including the motivation, principle, challenges and research activities around the world. The status and future plan of the Chinease ADS (C-ADS) project will be highlighted and discussed in depth as an example.

  16. Representing Identity and Equivalence for Scientific Data

    NASA Astrophysics Data System (ADS)

    Wickett, K. M.; Sacchi, S.; Dubin, D.; Renear, A. H.

    2012-12-01

    Matters of equivalence and identity are central to the stewardship of scientific data. In order to properly prepare for and manage the curation, preservation and sharing of digitally-encoded data, data stewards must be able to characterize and assess the relationships holding between data-carrying digital resources. However, identity-related questions about resources and their information content may not be straightforward to answer: for example, what exactly does it mean to say that two files contain the same data, but in different formats? Information content is frequently distinguished from particular representations, but there is no adequately developed shared understanding of what this really means and how the relationship between content and its representations hold. The Data Concepts group at the Center for Informatics Research in Science and Scholarship (CIRSS), University of Illinois at Urbana Champaign, is developing a logic-based framework of fundamental concepts related to scientific data to support curation and integration. One project goal is to develop precise accounts of information resources carrying the same data. We present two complementary conceptual models for information representation: the Basic Representation Model (BRM) and the Systematic Assertion Model (SAM). We show how these models provide an analytical account of digitally-encoded scientific data and a precise understanding of identity and equivalence. The Basic Representation Model identifies the core entities and relationships involved in representing information carried by digital objects. In BRM, digital objects are symbol structures that express propositional content, and stand in layered encoding relationships. For example, an RDF description may be serialized as either XML or N3, and those expressions in turn may be encoded as either UTF-8 or UTF-16 sequences. Defining this encoding stack reveals distinctions necessary for a precise account of identity and equivalence

  17. SHORT ACCELERATION TIMES FROM SUPERDIFFUSIVE SHOCK ACCELERATION IN THE HELIOSPHERE

    SciTech Connect

    Perri, S.; Zimbardo, G.

    2015-12-10

    The analysis of time profiles of particles accelerated at interplanetary shocks allows particle transport properties to be inferred. The frequently observed power-law decay upstream, indeed, implies a superdiffusive particle transport when the level of magnetic field variance does not change as the time interval from the shock front increases. In this context, a superdiffusive shock acceleration (SSA) theory has been developed, allowing us to make predictions of the acceleration times. In this work we estimate for a number of interplanetary shocks, including the solar wind termination shock, the acceleration times for energetic protons in the framework of SSA and we compare the results with the acceleration times predicted by standard diffusive shock acceleration. The acceleration times due to SSA are found to be much shorter than in the classical model, and also shorter than the interplanetary shock lifetimes. This decrease of the acceleration times is due to the scale-free nature of the particle displacements in the framework of superdiffusion. Indeed, very long displacements are possible, increasing the probability for particles far from the front of the shock to return, and short displacements have a high probability of occurrence, increasing the chances for particles close to the front to cross the shock many times.

  18. Electron Acceleration in Contracting Magnetic Islands during Solar Flares

    NASA Astrophysics Data System (ADS)

    Borovikov, D.; Tenishev, V.; Gombosi, T. I.; Guidoni, S. E.; DeVore, C. R.; Karpen, J. T.; Antiochos, S. K.

    2017-01-01

    Electron acceleration in solar flares is well known to be efficient at generating energetic particles that produce the observed bremsstrahlung X-ray spectra. One mechanism proposed to explain the observations is electron acceleration within contracting magnetic islands formed by magnetic reconnection in the flare current sheet. In a previous study, a numerical magnetohydrodynamic simulation of an eruptive solar flare was analyzed to estimate the associated electron acceleration due to island contraction. That analysis used a simple analytical model for the island structure and assumed conservation of the adiabatic invariants of particle motion. In this paper, we perform the first-ever rigorous integration of the guiding-center orbits of electrons in a modeled flare. An initially isotropic distribution of particles is seeded in a contracting island from the simulated eruption, and the subsequent evolution of these particles is followed using guiding-center theory. We find that the distribution function becomes increasingly anisotropic over time as the electrons’ energy increases by up to a factor of five, in general agreement with the previous study. In addition, we show that the energized particles are concentrated on the Sunward side of the island, adjacent to the reconnection X-point in the flare current sheet. Furthermore, our analysis demonstrates that the electron energy gain is dominated by betatron acceleration in the compressed, strengthened magnetic field of the contracting island. Fermi acceleration by the shortened field lines of the island also contributes to the energy gain, but it is less effective than the betatron process.

  19. Summary Report of Mission Acceleration Measurements for STS-89

    NASA Technical Reports Server (NTRS)

    Hrovat, Kenneth; McPherson, Kevin

    1999-01-01

    Support of microgravity research on the 89th flight of the Space Transportation System (STS-89) and a continued effort to characterize the acceleration environment of the Space Shuttle Orbiter and the Mir Space Station form the basis for this report. For the STS-89 mission, the Space Shuttle Endeavour was equipped with a Space Acceleration Measurement System (SAMS) unit, which collected more than a week's worth of data. During docked operations with Mir, a second SAMS unit collected approximately a day's worth of data yielding the only set of acceleration measurements recorded simultaneously on the two spacecraft. Based on the data acquired by these SAMS units, this report serves to characterize a number of acceleration events and quantify their impact on the local nature of the accelerations experienced at the Mechanics of Granular Materials (MGM) experiment location. Crew activity was shown to nearly double the median root-mean-square (RMS) acceleration level calculated below 10 Hz, while the Enhanced Orbiter Refrigerator/Freezer operating at about 22 Hz was a strong acceleration source in the vicinity of the MGM location. The MGM science requirement that the acceleration not exceed plus or minus 1 mg was violated numerous times during their experiment runs; however, no correlation with sample instability has been found to this point. Synchronization between the SAMS data from Endeavour and from Mir was shown to be close much of the time, but caution with respect to exact timing should be exercised when comparing these data. When orbiting as a separate vehicle prior to docking, Endeavour had prominent structural modes above 3 Hz, while Mir exhibited a cluster of modes around 1 Hz. When mated, a transition to common modes was apparent in the two SAMS data sets. This report is not a comprehensive analysis of the acceleration data, so those interested in further details should contact the Principal Investigator Microgravity Services team at the National Aeronautics

  20. Intrinsic normalized emittance growth in laser-driven electron accelerators

    NASA Astrophysics Data System (ADS)

    Migliorati, M.; Bacci, A.; Benedetti, C.; Chiadroni, E.; Ferrario, M.; Mostacci, A.; Palumbo, L.; Rossi, A. R.; Serafini, L.; Antici, P.

    2013-01-01

    Laser-based electron sources are attracting strong interest from the conventional accelerator community due to their unique characteristics in terms of high initial energy, low emittance, and significant beam current. Extremely strong electric fields (up to hundreds of GV/m) generated in the plasma allow accelerating gradients much higher than in conventional accelerators and set the basis for achieving very high final energies in a compact space. Generating laser-driven high-energy electron beam lines therefore represents an attractive challenge for novel particle accelerators. In this paper we show that laser-driven electrons generated by the nowadays consolidated TW laser systems, when leaving the interaction region, are subject to a very strong, normalized emittance worsening which makes them quickly unusable for any beam transport. Furthermore, due to their intrinsic beam characteristics, controlling and capturing the full beam current can only be achieved improving the source parameters.

  1. Distribution of the background gas in the MITICA accelerator

    NASA Astrophysics Data System (ADS)

    Sartori, E.; Dal Bello, S.; Serianni, G.; Sonato, P.

    2013-02-01

    MITICA is the ITER neutral beam test facility to be built in Padova for the generation of a 40A D- ion beam with a 16×5×16 array of 1280 beamlets accelerated to 1MV. The background gas pressure distribution and the particle flows inside MITICA accelerator are critical aspects for stripping losses, generation of secondary particles and beam non-uniformities. To keep the stripping losses in the extraction and acceleration stages reasonably low, the source pressure should be 0.3 Pa or less. The gas flow in MITICA accelerator is being studied using a 3D Finite Element code, named Avocado. The gas-wall interaction model is based on the cosine law, and the whole vacuum system geometry is represented by a view factor matrix based on surface discretization and gas property definitions. Pressure distribution and mutual fluxes are then solved linearly. In this paper the result of a numerical simulation is presented, showing the steady-state pressure distribution inside the accelerator when gas enters the system at room temperature. The accelerator model is limited to a horizontal slice 400 mm high (1/4 of the accelerator height). The pressure profile at solid walls and through the beamlet axis is obtained, allowing the evaluation and the discussion of the background gas distribution and nonuniformity. The particle flux at the inlet and outlet boundaries (namely the grounded grid apertures and the lateral conductances respectively) will be discussed.

  2. Numerical and laboratory simulations of auroral acceleration

    SciTech Connect

    Gunell, H.; De Keyser, J.; Mann, I.

    2013-10-15

    The existence of parallel electric fields is an essential ingredient of auroral physics, leading to the acceleration of particles that give rise to the auroral displays. An auroral flux tube is modelled using electrostatic Vlasov simulations, and the results are compared to simulations of a proposed laboratory device that is meant for studies of the plasma physical processes that occur on auroral field lines. The hot magnetospheric plasma is represented by a gas discharge plasma source in the laboratory device, and the cold plasma mimicking the ionospheric plasma is generated by a Q-machine source. In both systems, double layers form with plasma density gradients concentrated on their high potential sides. The systems differ regarding the properties of ion acoustic waves that are heavily damped in the magnetosphere, where the ion population is hot, but weakly damped in the laboratory, where the discharge ions are cold. Ion waves are excited by the ion beam that is created by acceleration in the double layer in both systems. The efficiency of this beam-plasma interaction depends on the acceleration voltage. For voltages where the interaction is less efficient, the laboratory experiment is more space-like.

  3. Fermilab Tevatron high level RF accelerating systems

    NASA Astrophysics Data System (ADS)

    Kerns, Q.; Kerns, C.; Miller, H.; Tawser, S.; Reid, J.; Webber, R.; Wildman, D.

    1985-06-01

    Eight tuned RF cavities have been installed and operated in the F0 straight section of the Tevatron. Their mechanical placement along the beam line enables them to be operated for colliding beams as two independent groups of four cavities, group 1-4 accelerating antiprotons and group 5-8 accelerating protons. The only difference is that the spacing between cavities 4 and 5 was increased to stay clear of the F0 colliding point. The cavities can easily be rephased by switching cables in a low-level distribution system (fan-out) so that the full accelerating capability of all eight cavities can be used during a fixed target operations. Likewise, the cables from capacitive probes on each cavity gap can be switched to proper lengths and summed in a fan-back system to give an RF signal representing the amplitude and phase as seen by the beam separately for protons and antiprotons. Such signals have been used to phase lock the Tevatron to the Main Ring for synchronous transfer.

  4. Electrokinetic acceleration of DNA hybridization in microsystems.

    PubMed

    Lei, Kin Fong; Wang, Yun-Hsiang; Chen, Huai-Yi; Sun, Jia-Hong; Cheng, Ji-Yen

    2015-06-01

    In this work, electrokinetic acceleration of DNA hybridization was investigated by different combinations of frequencies and amplitudes of actuating electric signals. Because the frequencies from low to high can induce different kinds of electrokinetic forces, i.e., electroosmotic to electrothermal forces, this work provides an in-depth investigation of electrokinetic enhanced hybridization. Concentric circular Cr/Au microelectrodes of 350 µm in diameter were fabricated on a glass substrate and probe DNA was immobilized on the electrode surface. Target DNA labeled with fluorescent dyes suspending in solution was then applied to the electrode. Different electrokinetic forces were induced by the application of different electric signals to the circular microelectrodes. Local microfluidic vortexes were generated to increase the collision efficiency between the target DNA suspending in solution and probe DNA immobilized on the electrode surface. DNA hybridization on the electrode surface could be accelerated by the electrokinetic forces. The level of hybridization was represented by the fluorescent signal intensity ratio. Results revealed that such 5-min dynamic hybridization increased 4.5 fold of signal intensity ratio as compared to a 1-h static hybridization. Moreover, dynamic hybridization was found to have better differentiation ability between specific and non-specific target DNA. This study provides a strategy to accelerate DNA hybridization in microsystems.

  5. Optimization of the factors that accelerate leaching

    SciTech Connect

    Fuhrmann, M.; Pietrzak, R.F.; Franz, E.M.; Heiser, J.H. III; Colombo, P.

    1989-03-01

    The prediction of long-term leachability of low-level radioactive waste forms is an essential element of disposal-site performance assessment. This report describes experiments and modeling techniques used to develop an accelerated leach test that meets this need. The acceleration in leaching rates caused by the combinations of two or more factors were experimentally determined. These factors were identified earlier as being able to individually accelerate leaching. They are: elevated temperature, the size of the waste form, the ratio of the volume of leachant to the surface area of the waste form, and the frequency of replacement of the leachant. The solidification agents employed were ones that are currently used to treat low-level radioactive wastes, namely portland type I cement, bitumen, and vinyl ester-styrene. The simulated wastes, sodium sulfate, sodium tetraborate, and incinerator ash, are simplified representatives of typical low-level waste streams. Experiments determined the leaching behavior of the radionuclides of cesium (Cs-137), strontium (Sr-85), and cobalt (Co-60 or Co-57) from several different formulations of solidification agents and waste types. Leaching results were based upon radiochemical and elemental analyses of aliquots of the leachate, and on its total alkalinity and pH at various times during the experiment (up to 120 days). Solid phase analyses were carried out by Scanning/Electron Microscopy and Energy Dispersive Spectroscopy on the waste forms before and after some leaching experiments. 43 refs., 96 figs., 16 tabs.

  6. A Potential Role of Double Layers on Solar Wind Acceleration

    NASA Astrophysics Data System (ADS)

    Parks, G. K.; McCarthy, M.; Lee, E.; Hong, J.

    2012-12-01

    The distribution function of solar wind (SW) is non-Maxwellian and often includes field-aligned beams. Recently, electrostatic solitary waves (ESW) have been observed in the SW and they have been interpreted as double layers. Taking a cue from Earth's auroral observations that large-scale electric field parallel to magnetic field may be due to many double layers distributed along the geomagnetic field, we have looked at the potential role double layers could play in SW acceleration. This picture would suggest that the halo component of the SW represents a beam that has been accelerated by parallel electric field. The core electrons come from secondaries produced by the beam going through the solar coronal atmosphere. The source of the super-halo component is not known and we speculate that it could represent the field-aligned non-thermal high-energy halo electrons that have been accelerated to ``runaway" energies.

  7. Argonne's Laboratory computing center - 2007 annual report.

    SciTech Connect

    Bair, R.; Pieper, G. W.

    2008-05-28

    Argonne National Laboratory founded the Laboratory Computing Resource Center (LCRC) in the spring of 2002 to help meet pressing program needs for computational modeling, simulation, and analysis. The guiding mission is to provide critical computing resources that accelerate the development of high-performance computing expertise, applications, and computations to meet the Laboratory's challenging science and engineering missions. In September 2002 the LCRC deployed a 350-node computing cluster from Linux NetworX to address Laboratory needs for mid-range supercomputing. This cluster, named 'Jazz', achieved over a teraflop of computing power (1012 floating-point calculations per second) on standard tests, making it the Laboratory's first terascale computing system and one of the 50 fastest computers in the world at the time. Jazz was made available to early users in November 2002 while the system was undergoing development and configuration. In April 2003, Jazz was officially made available for production operation. Since then, the Jazz user community has grown steadily. By the end of fiscal year 2007, there were over 60 active projects representing a wide cross-section of Laboratory expertise, including work in biosciences, chemistry, climate, computer science, engineering applications, environmental science, geoscience, information science, materials science, mathematics, nanoscience, nuclear engineering, and physics. Most important, many projects have achieved results that would have been unobtainable without such a computing resource. The LCRC continues to foster growth in the computational science and engineering capability and quality at the Laboratory. Specific goals include expansion of the use of Jazz to new disciplines and Laboratory initiatives, teaming with Laboratory infrastructure providers to offer more scientific data management capabilities, expanding Argonne staff use of national computing facilities, and improving the scientific reach and

  8. Using inverted indices for accelerating LINGO calculations.

    PubMed

    Kristensen, Thomas G; Nielsen, Jesper; Pedersen, Christian N S

    2011-03-28

    The ever growing size of chemical databases calls for the development of novel methods for representing and comparing molecules. One such method called LINGO is based on fragmenting the SMILES string representation of molecules. Comparison of molecules can then be performed by calculating the Tanimoto coefficient, which is called LINGOsim when used on LINGO multisets. This paper introduces a verbose representation for storing LINGO multisets, which makes it possible to transform them into sparse fingerprints such that fingerprint data structures and algorithms can be used to accelerate queries. The previous best method for rapidly calculating the LINGOsim similarity matrix required specialized hardware to yield a significant speedup over existing methods. By representing LINGO multisets in the verbose representation and using inverted indices, it is possible to calculate LINGOsim similarity matrices roughly 2.6 times faster than existing methods without relying on specialized hardware.

  9. Inclined Planes and Motion Detectors: A Study of Acceleration.

    ERIC Educational Resources Information Center

    Tracy, Dyanne M.

    2001-01-01

    Presents an activity in which students work in cooperative groups and roll balls down inclined planes, collect data with the help of an electronic motion detector, and represent data with a graphing calculator to explore concepts such as mass, gravity, velocity, and acceleration. (Contains 12 references.) (Author/ASK)

  10. Experiment to Detect Accelerating Modes in a Photonic Bandgap Fiber

    SciTech Connect

    England, R.J.; Colby, E.R.; Ischebeck, R.; McGuinness, C.M.; Noble, R.; Plettner, T.; Sears, C.M.S.; Siemann, R.H.; Spencer, J.E.; Walz, D.; /SLAC

    2011-11-21

    An experimental effort is currently underway at the E-163 test beamline at Stanford Linear Accelerator Center to use a hollow-core photonic bandgap (PBG) fiber as a high-gradient laser-based accelerating structure for electron bunches. For the initial stage of this experiment, a 50pC, 60 MeV electron beam will be coupled into the fiber core and the excited modes will be detected using a spectrograph to resolve their frequency signatures in the wakefield radiation generated by the beam. They will describe the experimental plan and recent simulation studies of candidate fibers.

  11. Experiment to Detect Accelerating Modes in a Photonic Bandgap Fiber

    SciTech Connect

    England, R. J.; Colby, E. R.; McGuinness, C. M.; Noble, R.; Plettner, T.; Siemann, R. H.; Spencer, J. E.; Walz, D.; Ischebeck, R.; Sears, C. M. S.

    2009-01-22

    An experimental effort is currently underway at the E-163 test beamline at Stanford Linear Accelerator Center to use a hollow-core photonic bandgap (PBG) fiber as a high-gradient laser-based accelerating structure for electron bunches. For the initial stage of this experiment, a 50 pC, 60 MeV electron beam will be coupled into the fiber core and the excited modes will be detected using a spectrograph to resolve their frequency signatures in the wakefield radiation generated by the beam. We will describe the experimental plan and recent simulation studies of candidate fibers.

  12. Directionality of Flare-Accelerated Alpha Particles at the Sun

    DTIC Science & Technology

    2003-01-01

    Directionality of Flare-Accelerated α Particles at the Sun Gerald H. Share, Ronald J. Murphy E.O. Hulburt Center for Space Research, Naval Research...2003 2. REPORT TYPE 3. DATES COVERED 00-00-2003 to 00-00-2003 4. TITLE AND SUBTITLE Directionality of Flare-Accelerated a Particles at the Sun 5a...one which is isotropic in the hemisphere towards the solar surface and has no component away from the Sun ) exhibits a broad struc- – 4 – ture from

  13. Teaching and Research with Accelerators at Tarleton State University

    SciTech Connect

    Marble, Daniel K.

    2009-03-10

    Tarleton State University students began performing both research and laboratory experiments using accelerators in 1998 through visitation programs at the University of North Texas, US Army Research Laboratory, and the Naval Surface Warfare Center at Carderock. In 2003, Tarleton outfitted its new science building with a 1 MV pelletron that was donated by the California Institution of Technology. The accelerator has been upgraded and supports a wide range of classes for both the Physics program and the ABET accredited Engineering Physics program as well as supplying undergraduate research opportunities on campus. A discussion of various laboratory activities and research projects performed by Tarleton students will be presented.

  14. Thomas Edison Accelerated Elementary School.

    ERIC Educational Resources Information Center

    Levin, Henry M.; Chasin, Gene

    This paper describes early outcomes of a Sacramento, California, elementary school that participated in the Accelerated Schools Project. The school, which serves many minority and poor students, began training for the project in 1992. Accelerated Schools were designed to advance the learning rate of students through a gifted and talented approach,…

  15. Natural Acceleration: Supporting Creative Trajectories

    ERIC Educational Resources Information Center

    Cohen, LeoNora M.

    2011-01-01

    "Natural acceleration" happens through an internal fire that burns to learn and may transcend school boundaries. Based on their passionate interests and connections with a domain, children who hunger for domain understandings outside school curricula require different types of acceleration, motivated by these interests. The lifeworks,…

  16. COMPASS Accelerator Design Technical Overview

    SciTech Connect

    Nanni, Emilio; Dolgashev, Valery; Tantawi, Sami; Neilson, Jeff

    2016-03-14

    This report is a survey of technical options for generating a MeV-class accelerator for space based science applications. The survey was performed focusing on the primary technical requirements of the accelerator in the context of a satellite environment with its unique challenges of limited electrical power (PE), thermal isolation, dimensions, payload requirement and electrical isolation.

  17. Switching mechanism senses angular acceleration

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Switching mechanism actuates an electrical circuit when a predetermined angular acceleration and displacement are reached. A rotor in the mechanism overcomes the restraint of a magnetic detent when the case in which the detent is mounted reaches the predetermined angular acceleration.

  18. General purpose programmable accelerator board

    DOEpatents

    Robertson, Perry J.; Witzke, Edward L.

    2001-01-01

    A general purpose accelerator board and acceleration method comprising use of: one or more programmable logic devices; a plurality of memory blocks; bus interface for communicating data between the memory blocks and devices external to the board; and dynamic programming capabilities for providing logic to the programmable logic device to be executed on data in the memory blocks.

  19. EXOTIC MAGNETS FOR ACCELERATORS.

    SciTech Connect

    WANDERER, P.

    2005-09-18

    Over the last few years, several novel magnet designs have been introduced to meet the requirements of new, high performance accelerators and beam lines. For example, the FAIR project at GSI requires superconducting magnets ramped at high rates ({approx} 4 T/s) in order to achieve the design intensity. Magnets for the RIA and FAIR projects and for the next generation of LHC interaction regions will need to withstand high doses of radiation. Helical magnets are required to maintain and control the polarization of high energy protons at RHIC. In other cases, novel magnets have been designed in response to limited budgets and space. For example, it is planned to use combined function superconducting magnets for the 50 GeV proton transport line at J-PARC to satisfy both budget and performance requirements. Novel coil winding methods have been developed for short, large aperture magnets such as those used in the insertion region upgrade at BEPC. This paper will highlight the novel features of these exotic magnets.

  20. Energy Innovation Acceleration Program

    SciTech Connect

    Wolfson, Johanna

    2015-06-15

    The Energy Innovation Acceleration Program (IAP) – also called U-Launch – has had a significant impact on early stage clean energy companies in the Northeast and on the clean energy economy in the Northeast, not only during program execution (2010-2014), but continuing into the future. Key results include: Leverage ratio of 105:1; $105M in follow-on funding (upon $1M investment by EERE); At least 19 commercial products launched; At least 17 new industry partnerships formed; At least $6.5M in revenue generated; >140 jobs created; 60% of assisted companies received follow-on funding within 1 year of program completion; In addition to the direct measurable program results summarized above, two primary lessons emerged from our work executing Energy IAP:; Validation and demonstration awards have an outsized, ‘tipping-point’ effect for startups looking to secure investments and strategic partnerships. An ecosystem approach is valuable, but an approach that evaluates the needs of individual companies and then draws from diverse ecosystem resources to fill them, is most valuable of all.

  1. Pulsars and Acceleration Sites

    NASA Technical Reports Server (NTRS)

    Harding, Alice

    2008-01-01

    Rotation-powered pulsars are excellent laboratories for the studying particle acceleration as well as fundamental physics of strong gravity, strong magnetic fields and relativity. But even forty years after their discovery, we still do not understand their pulsed emission at any wavelength. I will review both the basic physics of pulsars as well as the latest developments in understanding their high-energy emission. Special and general relativistic effects play important roles in pulsar emission, from inertial frame-dragging near the stellar surface to aberration, time-of-flight and retardation of the magnetic field near the light cylinder. Understanding how these effects determine what we observe at different wavelengths is critical to unraveling the emission physics. Fortunately the Gamma-Ray Large Area Space Telescope (GLAST), with launch in May 2008 will detect many new gamma-ray pulsars and test the predictions of these models with unprecedented sensitivity and energy resolution for gamma-rays in the range of 30 MeV to 300 GeV.

  2. RFQ accelerator tuning system

    DOEpatents

    Bolie, Victor W.

    1990-01-01

    A cooling system is provided for maintaining a preselected operating temperature in a device, which may be an RFQ accelerator, having a variable heat removal requirement, by circulating a cooling fluid through a cooling system remote from the device. Internal sensors in the device enable an estimated error signal to be generated from parameters which are indicative of the heat removal requirement from the device. Sensors are provided at predetermined locations in the cooling system for outputting operational temperature signals. Analog and digital computers define a control signal functionally related to the temperature signals and the estimated error signal, where the control signal is defined effective to return the device to the preselected operating temperature in a stable manner. The cooling system includes a first heat sink responsive to a first portion of the control signal to remove heat from a major portion of the circulating fluid. A second heat sink is responsive to a second portion of the control signal to remove heat from a minor portion of the circulating fluid. The cooled major and minor portions of the circulating fluid are mixed in response to a mixing portion of the control signal, which is effective to proportion the major and minor portions of the circulating fluid to establish a mixed fluid temperature which is effective to define the preselected operating temperature for the remote device. In an RFQ environment the stable temperature control enables the resonant frequency of the device to be maintained at substantially a predetermined value during transient operations.

  3. RFQ accelerator tuning system

    DOEpatents

    Bolie, V.W.

    1990-07-03

    A cooling system is provided for maintaining a preselected operating temperature in a device, which may be an RFQ accelerator, having a variable heat removal requirement, by circulating a cooling fluid through a cooling system remote from the device. Internal sensors in the device enable an estimated error signal to be generated from parameters which are indicative of the heat removal requirement from the device. Sensors are provided at predetermined locations in the cooling system for outputting operational temperature signals. Analog and digital computers define a control signal functionally related to the temperature signals and the estimated error signal, where the control signal is defined effective to return the device to the preselected operating temperature in a stable manner. The cooling system includes a first heat sink responsive to a first portion of the control signal to remove heat from a major portion of the circulating fluid. A second heat sink is responsive to a second portion of the control signal to remove heat from a minor portion of the circulating fluid. The cooled major and minor portions of the circulating fluid are mixed in response to a mixing portion of the control signal, which is effective to proportion the major and minor portions of the circulating fluid to establish a mixed fluid temperature which is effective to define the preselected operating temperature for the remote device. In an RFQ environment the stable temperature control enables the resonant frequency of the device to be maintained at substantially a predetermined value during transient operations. 3 figs.

  4. Is Global Warming Accelerating?

    NASA Astrophysics Data System (ADS)

    Shukla, J.; Delsole, T. M.; Tippett, M. K.

    2009-12-01

    A global pattern that fluctuates naturally on decadal time scales is identified in climate simulations and observations. This newly discovered component, called the Global Multidecadal Oscillation (GMO), is related to the Atlantic Meridional Oscillation and shown to account for a substantial fraction of decadal fluctuations in the observed global average sea surface temperature. IPCC-class climate models generally underestimate the variance of the GMO, and hence underestimate the decadal fluctuations due to this component of natural variability. Decomposing observed sea surface temperature into a component due to anthropogenic and natural radiative forcing plus the GMO, reveals that most multidecadal fluctuations in the observed global average sea surface temperature can be accounted for by these two components alone. The fact that the GMO varies naturally on multidecadal time scales implies that it can be predicted with some skill on decadal time scales, which provides a scientific rationale for decadal predictions. Furthermore, the GMO is shown to account for about half of the warming in the last 25 years and hence a substantial fraction of the recent acceleration in the rate of increase in global average sea surface temperature. Nevertheless, in terms of the global average “well-observed” sea surface temperature, the GMO can account for only about 0.1° C in transient, decadal-scale fluctuations, not the century-long 1° C warming that has been observed during the twentieth century.

  5. Accelerated Adaptive Integration Method

    PubMed Central

    2015-01-01

    Conformational changes that occur upon ligand binding may be too slow to observe on the time scales routinely accessible using molecular dynamics simulations. The adaptive integration method (AIM) leverages the notion that when a ligand is either fully coupled or decoupled, according to λ, barrier heights may change, making some conformational transitions more accessible at certain λ values. AIM adaptively changes the value of λ in a single simulation so that conformations sampled at one value of λ seed the conformational space sampled at another λ value. Adapting the value of λ throughout a simulation, however, does not resolve issues in sampling when barriers remain high regardless of the λ value. In this work, we introduce a new method, called Accelerated AIM (AcclAIM), in which the potential energy function is flattened at intermediate values of λ, promoting the exploration of conformational space as the ligand is decoupled from its receptor. We show, with both a simple model system (Bromocyclohexane) and the more complex biomolecule Thrombin, that AcclAIM is a promising approach to overcome high barriers in the calculation of free energies, without the need for any statistical reweighting or additional processors. PMID:24780083

  6. Accelerated shallow water modeling

    NASA Astrophysics Data System (ADS)

    Gandham, Rajesh; Medina, David; Warburton, Timothy

    2015-04-01

    ln this talk we will describe our ongoing developments in accelerated numerical methods for modeling tsunamis, and oceanic fluid flows using two dimensional shallow water model and/or three dimensional incompressible Navier Stokes model discretized with high order discontinuous Galerkin methods. High order discontinuous Galerkin methods can be computationally demanding, requiring extensive computational time to simulate real time events on traditional CPU architectures. However, recent advances in computing architectures and hardware aware algorithms make it possible to reduce simulation time and provide accurate predictions in a timely manner. Hence we tailor these algorithms to take advantage of single instruction multiple data (SIMD) architecture that is seen in modern many core compute devices such as GPUs. We will discuss our unified and extensive many-core programming library OCCA that alleviates the need to completely re-design the solvers to keep up with constantly evolving parallel programming models and hardware architectures. We will present performance results for the flow simulations demonstrating performance leveraging multiple different multi-threading APIs on GPU and CPU targets.

  7. Hot Spot Cosmic Accelerators

    NASA Astrophysics Data System (ADS)

    2002-11-01

    length of more than 3 million light-years, or no less than one-and-a-half times the distance from the Milky Way to the Andromeda galaxy, this structure is indeed gigantic. The region where the jets collide with the intergalactic medium are known as " hot spots ". Superposing the intensity contours of the radio emission from the southern "hot spot" on a near-infrared J-band (wavelength 1.25 µm) VLT ISAAC image ("b") shows three distinct emitting areas; they are even better visible on the I-band (0.9 µm) FORS1 image ("c"). This emission is obviously associated with the shock front visible on the radio image. This is one of the first times it has been possible to obtain an optical/near-IR image of synchrotron emission from such an intergalactic shock and, thanks to the sensitivity and image sharpness of the VLT, the most detailed view of its kind so far . The central area (with the strongest emission) is where the plasma jet from the galaxy centre hits the intergalactic medium. The light from the two other "knots", some 10 - 15,000 light-years away from the central "hot spot", is also interpreted as synchrotron emission. However, in view of the large distance, the astronomers are convinced that it must be caused by electrons accelerated in secondary processes at those sites . The new images thus confirm that electrons are being continuously accelerated in these "knots" - hence called "cosmic accelerators" - far from the galaxy and the main jets, and in nearly empty space. The exact physical circumstances of this effect are not well known and will be the subject of further investigations. The present VLT-images of the "hot spots" near 3C 445 may not have the same public appeal as some of those beautiful images that have been produced by the same instruments during the past years. But they are not less valuable - their unusual importance is of a different kind, as they now herald the advent of fundamentally new insights into the mysteries of this class of remote and active

  8. Touch Accelerates Visual Awareness

    PubMed Central

    Lo Verde, Luca; Alais, David

    2017-01-01

    To efficiently interact with the external environment, our nervous system combines information arising from different sensory modalities. Recent evidence suggests that cross-modal interactions can be automatic and even unconscious, reflecting the ecological relevance of cross-modal processing. Here, we use continuous flash suppression (CFS) to directly investigate whether haptic signals can interact with visual signals outside of visual awareness. We measured suppression durations of visual gratings rendered invisible by CFS either during visual stimulation alone or during visuo-haptic stimulation. We found that active exploration of a haptic grating congruent in orientation with the suppressed visual grating reduced suppression durations both compared with visual-only stimulation and to incongruent visuo-haptic stimulation. We also found that the facilitatory effect of touch on visual suppression disappeared when the visual and haptic gratings were mismatched in either spatial frequency or orientation. Together, these results demonstrate that congruent touch can accelerate the rise to consciousness of a suppressed visual stimulus and that this unconscious cross-modal interaction depends on visuo-haptic congruency. Furthermore, since CFS suppression is thought to occur early in visual cortical processing, our data reinforce the evidence suggesting that visuo-haptic interactions can occur at the earliest stages of cortical processing. PMID:28210486

  9. Dryden Flight Research Center: Center Overview

    NASA Technical Reports Server (NTRS)

    Ratnayake, Nalin

    2009-01-01

    This viewgraph presentation describes a general overview of Dryden Flight Research Center. Strategic partnerships, Dryden's mission activity, exploration systems and aeronautics research programs are also described.

  10. Electron cyclotron harmonic wave acceleration

    NASA Technical Reports Server (NTRS)

    Karimabadi, H.; Menyuk, C. R.; Sprangle, P.; Vlahos, L.

    1987-01-01

    A nonlinear analysis of particle acceleration in a finite bandwidth, obliquely propagating electromagnetic cyclotron wave is presented. It has been suggested by Sprangle and Vlahos in 1983 that the narrow bandwidth cyclotron radiation emitted by the unstable electron distribution inside a flaring solar loop can accelerate electrons outside the loop by the interaction of a monochromatic wave propagating along the ambient magnetic field with the ambient electrons. It is shown here that electrons gyrating and streaming along a uniform, static magnetic field can be accelerated by interacting with the fundamental or second harmonic of a monochromatic, obliquely propagating cyclotron wave. It is also shown that the acceleration is virtually unchanged when a wave with finite bandwidth is considered. This acceleration mechanism can explain the observed high-energy electrons in type III bursts.

  11. Shear Acceleration in Expanding Flows

    NASA Astrophysics Data System (ADS)

    Rieger, F. M.; Duffy, P.

    2016-12-01

    Shear flows are naturally expected to occur in astrophysical environments and potential sites of continuous non-thermal Fermi-type particle acceleration. Here we investigate the efficiency of expanding relativistic outflows to facilitate the acceleration of energetic charged particles to higher energies. To this end, the gradual shear acceleration coefficient is derived based on an analytical treatment. The results are applied to the context of the relativistic jets from active galactic nuclei. The inferred acceleration timescale is investigated for a variety of conical flow profiles (i.e., power law, Gaussian, Fermi-Dirac) and compared to the relevant radiative and non-radiative loss timescales. The results exemplify that relativistic shear flows are capable of boosting cosmic-rays to extreme energies. Efficient electron acceleration, on the other hand, requires weak magnetic fields and may thus be accompanied by a delayed onset of particle energization and affect the overall jet appearance (e.g., core, ridge line, and limb-brightening).

  12. The ISAC post-accelerator

    NASA Astrophysics Data System (ADS)

    Laxdal, R. E.; Marchetto, M.

    2014-01-01

    The acceleration chain of the ISAC facility boosts the energy of both radioactive and stable light and heavy ions for beam delivery to both a medium energy area in ISAC-I and a high energy area in ISAC-II. The post-accelerator comprises a 35.4 MHz RFQ to accelerate beams of A/q ≤ 30 from 2 keV/u to 150 keV/u and a post stripper, 106.1 MHz variable energy drift tube linac (DTL) to accelerate ions of A/q ≤ 6 to a final energy between 0.15 MeV/u to 1.5 MeV/u. A 40 MV superconducting linac further accelerates beam from 1.5 MeV/u to energies above the Coulomb barrier. All linacs operate cw to preserve beam intensity.

  13. Critical Issues in Plasma Accelerator

    NASA Astrophysics Data System (ADS)

    Uesaka, M.; Hosokai, T.

    2004-10-01

    Updated achievements and critical issues in plasma accelerators are summarized. As to laser plasma accelerators, we cover the results of plasma cathodes by U.Michigan, LBNL, LOA and U.Tokyo. Although many new results of accelerated electrons have been reported, the electrons do not yet form a bunch with narrow energy spread. Several injection schemes and measurements to verify ultrashort bunch (tens fs) with narrow energy spread, low emittance and many charges are planned. E-162 experiments by UCLA / USC / SLAC and a newly proposed experiment on density transition trapping are introduced for electron beam driven plasma accelerators. Their main purpose is realization of GeV plasma accelerator, but application to pump-and-probe analysis for investigation of ultrafast quantum phenomena is also promising.

  14. THE IMPORTANCE OF NEGATIVE ACCELERATION OF THE LOAD IN FREE-STYLE LIFTING.

    PubMed

    Trafimow, Jordan; Xaygnaraj, Joseph; Trafimow, David; Aruin, Alexander S

    2015-08-01

    Lifters may use negative acceleration in lifting a very light load. Body kinematic data were recorded in 10 participants lifting a 114 g box. Vertical position and acceleration of the center of mass and angle of the thigh to a vertical line were calculated. Acceleration data between the positions of the body when the thighs were horizontal and as the knees extended to an angle of 45° indicated that negative acceleration was present at 68.9% of time points, more than predicted by chance.

  15. Two-stage acceleration of protons from relativistic laser-solid interaction

    SciTech Connect

    Liu Jinlu; Sheng, Z. M.; Zheng, J.; Wang, W. M.; Yu, M. Y.; Liu, C. S.; Zhang, J.

    2012-12-21

    A two-stage proton acceleration scheme using present-day intense lasers and a unique target design is proposed. The target system consists of a hollow cylinder, inside which is a hollow cone, which is followed by the main target with a flat front and dish-like flared rear surface. At the center of the latter is a tapered proton layer, which is surrounded by outer proton layers at an angle to it. In the first acceleration stage, protons in both layers are accelerated by target normal sheath acceleration. The center-layer protons are accelerated forward along the axis and the side protons are accelerated and focused towards them. As a result, the side-layer protons radially compress as well as axially further accelerate the front part of the accelerating center-layer protons in the second stage, which are also radially confined and guided by the field of the fast electrons surrounding them. Two-dimensional particle-incell simulation shows that a 79fs 8.5 Multiplication-Sign 10{sup 20} W/cm{sup 2} laser pulse can produce a proton bunch with {approx} 267MeV maximum energy and {approx} 9.5% energy spread, which may find many applications, including cancer therapy.

  16. Student Success Center Toolkit

    ERIC Educational Resources Information Center

    Jobs For the Future, 2014

    2014-01-01

    "Student Success Center Toolkit" is a compilation of materials organized to assist Student Success Center directors as they staff, launch, operate, and sustain Centers. The toolkit features materials created and used by existing Centers, such as staffing and budgeting templates, launch materials, sample meeting agendas, and fundraising…

  17. Accelerating Star Formation in Clusters and Associations

    NASA Astrophysics Data System (ADS)

    Palla, Francesco; Stahler, Steven W.

    2000-09-01

    We use our own, recently developed pre-main-sequence evolutionary tracks to investigate the star formation histories of relatively nearby associations and clusters. We first employ published luminosities and effective temperatures to place the known members of each region in the H-R diagram. We then construct age histograms detailing that region's history. The groups studied include Taurus-Auriga, Lupus, Chamaeleon, ρ Ophiuchi, Upper Scorpius, IC 348, and NGC 2264. This study is the first to analyze a large number of star-forming regions with the same set of theoretical tracks. Our investigation corroborates and extends our previous results on the Orion Nebula Cluster. In all cases, we find that star formation began at a relatively low level some 107 yr in the past and has more recently undergone a steep acceleration. This acceleration, which lasts several million years, is usually continuing through the present epoch. The one clear exception is the OB association Upper Scorpius, where the formation rate climbed upward, peaked, and has now died off. Significantly, this is also the only region of our list that has been largely stripped of molecular gas. The acceleration represents a true physical phenomenon that cannot be explained away by incompleteness of the samples; nor is the pattern of stellar births significantly affected by observational errors or the presence of unresolved binaries. We speculate that increasing star formation activity arises from contraction of the parent cloud. Despite the short timescale for acceleration, the cloud is likely to evolve quasi-statically. Star formation itself appears to be a critical phenomenon, occurring only in locations exceeding some threshold density. The cloud's contraction must reverse itself, and the remnant gas dissipate, in less than 107 yr, even for aggregates containing no massive stars. In this case, molecular outflows from the stars themselves presumably accomplish the task, but the actual dispersal mechanism

  18. Effects of acceleration on gait measures in three horse gaits.

    PubMed

    Nauwelaerts, Sandra; Zarski, Lila; Aerts, Peter; Clayton, Hilary

    2015-05-01

    Animals switch gaits according to locomotor speed. In terrestrial locomotion, gaits have been defined according to footfall patterns or differences in center of mass (COM) motion, which characterizes mechanisms that are more general and more predictive than footfall patterns. This has generated different variables designed primarily to evaluate steady-speed locomotion, which is easier to standardize in laboratory conditions. However, in the ecology of an animal, steady-state conditions are rare and the ability to accelerate, decelerate and turn is essential. Currently, there are no data available that have tested whether COM variables can be used in accelerative or decelerative conditions. This study used a data set of kinematics and kinetics of horses using three gaits (walk, trot, canter) to evaluate the effects of acceleration (both positive and negative) on commonly used gait descriptors. The goal was to identify variables that distinguish between gaits both at steady state and during acceleration/deceleration. These variables will either be unaffected by acceleration or affected by it in a predictable way. Congruity, phase shift and COM velocity angle did not distinguish between gaits when the dataset included trials in unsteady conditions. Work (positive and negative) and energy recovery distinguished between gaits and showed a clear relationship with acceleration. Hodographs are interesting graphical representations to study COM mechanics, but they are descriptive rather than quantitative. Force angle, collision angle and collision fraction showed a U-shaped relationship with acceleration and seem promising tools for future research in unsteady conditions.

  19. Evidence for current sheet acceleration in the geomagnetic tail

    SciTech Connect

    Lyons, L.R.; Speiser, T.W.

    1982-04-01

    The existence of the current sheet and the dawn to dusk electric field in the geomagnetic tail implies there is particle energization in the tail current sheet of the order 2--10% of the total solar wind energy incident upon the dayside magnetopause. In this paper we determine that ion acceleration in a current sheet with a small magnetic field across the sheet, via single-particle motion which violates the guiding center approximation, can account for this large energization in the tail. We calculate the distribution of accelerated ions which result from the urrent sheet acceleration and compare the results with distributions of accelerated ions frequently observed flowing earthwards along the outer boundary of the plasma sheet. The comparison indicates that the observed earthward flowing ions result from current sheet acceleration. Comparison with measurements of auroral ion predictions at low precipitation at low altitudes implies that the accelerated ions ejected from the current sheet are also an important source of auroral ion precipitation. In addition, these acceletated ions may be an important source of plasma sheet ions.

  20. Accelerated Aging in Electrolytic Capacitors for Prognostics

    NASA Technical Reports Server (NTRS)

    Celaya, Jose R.; Kulkarni, Chetan; Saha, Sankalita; Biswas, Gautam; Goebel, Kai Frank

    2012-01-01

    The focus of this work is the analysis of different degradation phenomena based on thermal overstress and electrical overstress accelerated aging systems and the use of accelerated aging techniques for prognostics algorithm development. Results on thermal overstress and electrical overstress experiments are presented. In addition, preliminary results toward the development of physics-based degradation models are presented focusing on the electrolyte evaporation failure mechanism. An empirical degradation model based on percentage capacitance loss under electrical overstress is presented and used in: (i) a Bayesian-based implementation of model-based prognostics using a discrete Kalman filter for health state estimation, and (ii) a dynamic system representation of the degradation model for forecasting and remaining useful life (RUL) estimation. A leave-one-out validation methodology is used to assess the validity of the methodology under the small sample size constrain. The results observed on the RUL estimation are consistent through the validation tests comparing relative accuracy and prediction error. It has been observed that the inaccuracy of the model to represent the change in degradation behavior observed at the end of the test data is consistent throughout the validation tests, indicating the need of a more detailed degradation model or the use of an algorithm that could estimate model parameters on-line. Based on the observed degradation process under different stress intensity with rest periods, the need for more sophisticated degradation models is further supported. The current degradation model does not represent the capacitance recovery over rest periods following an accelerated aging stress period.