Science.gov

Sample records for accelerator experiment operations

  1. Accelerator/Experiment operations - FY 2004

    SciTech Connect

    Bromberg, C.; Conrad, J.; Denisov, D.; Holmes, S.; Louis, W.; Meyer, A.; Moore, Craig D.; Raja, R.; Ramberg, E.; Roser, R.; /Fermilab

    2004-12-01

    This Technical Memorandum (TM) summarizes the accelerator and experiment operations for FY 2004. It is one of a series of annual publications intended to gather information in one place. In this case, the information concerns the FY 2004 Run II at the Tevatron Collider, the MiniBooNE neutrino experiment, and SY 120 activities.

  2. Accelerator/Experiment Operations - FY 2010

    SciTech Connect

    Adamson, M.; Appel, J.A.; Casarsa, M.; Coleman, R.; Denisov, D.; Dixon, R.; Escobar, C.; Ginther, G.; Gruenendahl, S.; Harris, D.; Henderson, S.; /Fermilab

    2010-11-01

    This Technical Memorandum (TM) summarizes the Fermilab accelerator and accelerator experiment operations for FY 2010. It is one of a series of annual publications intended to gather information in one place. In this case, the information concerns the FY 2010 Run II at the Tevatron Collider, the MINOS and MINER?A experiments using the Main Injector Neutrino Beam (NuMI), the MiniBooNE experiment running in the Booster Neutrino Beam (BNB), and the Meson Test Beam (MTest) activities in the 120 GeV external Switchyard beam (SY120). Each section was prepared by the relevant authors, and was somewhat edited for inclusion in this summary.

  3. Accelerator/Experiment Operations - FY 2011

    SciTech Connect

    Adamson, P.; Bernardi, G.; Casarsa, M.; Coleman, R.; Denisov, D.; Dixon, R.; Ginther, G.; Gruenendahl, S.; Hahn, S.; Harris, D.; Henderson, S.

    2011-11-01

    This Technical Memorandum (TM) summarizes the Fermilab accelerator and accelerator experiment operations for FY 2011. It is one of a series of annual publications intended to gather information in one place. In this case, the information concerns the FY 2011 Run II at the Tevatron Collider, the MINOS and MINERvA experiments using the Main Injector Neutrino Beam (NuMI), the MiniBooNE experiment running in the Booster Neutrino Beam (BNB), and the Meson Test Beam (MTest) activities in the 120 GeV external Switchyard beam (SY120).

  4. Accelerator/Experiment Operations - FY 2007

    SciTech Connect

    Brice, S.; Buchanan, N.; Coleman, R.; Convery, M.; Denisov, D.; Ginther, G.; Habig, A.; Holmes, S.; Kissel, W.; Lee, W.; Nakaya, T.; /Fermilab

    2007-10-01

    This Technical Memorandum (TM) summarizes the Fermilab accelerator and accelerator experiment operations for FY 2007. It is one of a series of annual publications intended to gather information in one place. In this case, the information concerns the FY 2007 Run II at the Tevatron Collider, the MiniBooNE and SciBooNE experiments running in the Booster Neutrino Beam (BNB), MINOS using the Main Injector Neutrino Beam (NuMI), and the Meson Test Beam (MTest) activities in the 120 GeV external Switchyard beam (SY120). Each section was prepared by the relevant authors, and was somewhat edited for inclusion in this summary.

  5. Accelerator/Experiment Operations - FY 2008

    SciTech Connect

    Brice, Stephen J.; Buehler, M.; Casarsa, M.; Coleman, R.; Denisov, D.; Ginther, G.; Grinstein, S.; Habig, A.; Holmes, S.; Hylen, J.; Kissel, W.; /Fermilab

    2008-10-01

    This Technical Memorandum (TM) summarizes the Fermilab accelerator and accelerator experiment operations for FY 2008. It is one of a series of annual publications intended to gather information in one place. In this case, the information concerns the FY 2008 Run II at the Tevatron Collider, MINOS using the Main Injector Neutrino Beam (NuMI), the MiniBooNE and SciBooNE experiments running in the Booster Neutrino Beam (BNB), and the Meson Test Beam (MTest) activities in the 120 GeV external Switchyard beam (SY120).

  6. Accelerator/Experiment Operations - FY 2009

    SciTech Connect

    Andrews, M.N; Appel, J.A.; Brice, S.; Casarsa, M.; Coleman, R.; Denisov, d.; Ginther, G.; Gruenendahl, S.; Holmes, S.; Kissel, W.; Lee, W.M.; /Fermilab

    2009-10-01

    This Technical Memorandum (TM) summarizes the Fermilab accelerator and accelerator experiment operations for FY 2009. It is one of a series of annual publications intended to gather information in one place. In this case, the information concerns the FY 2009 Run II at the Tevatron Collider, MINOS using the Main Injector Neutrino Beam (NuMI), the MiniBooNE experiment running in the Booster Neutrino Beam (BNB), and the Meson Test Beam (MTest) activities in the 120 GeV external Switchyard beam (SY120). Each section was prepared by the relevant authors, and was somewhat edited for inclusion in this summary.

  7. Accelerator/Experiment operations - FY 2006

    SciTech Connect

    Brice, S.; Conrad, J.; Denisov, D.; Ginther, G.; Holmes, S.; James, C.; Lee, W.; Louis, W.; Moore, C.; Plunkett, R.; Raja, R.; /Fermilab

    2006-10-01

    This Technical Memorandum (TM) summarizes the Fermilab accelerator and experiment operations for FY 2006. It is one of a series of annual publications intended to gather information in one place. In this case, the information concerns the FY 2006 Run II at the Tevatron Collider, the MiniBooNE experiments running in the Booster Neutrino Beam in neutrino and antineutrino modes, MINOS using the Main Injector Neutrino Beam (NuMI), and SY 120 activities.

  8. Accelerator/Experiment Operations - FY 2015

    SciTech Connect

    Czarapata, P.

    2015-10-01

    This Technical Memorandum summarizes the Fermilab accelerator and experiment operations for FY 2015. It is one of a series of annual publications intended to gather information in one place. In this case, the information concerns the FY 2015 NOvA, MINOS+ and MINERvA experiments using the Main Injector Neutrino Beam (NuMI), the activities in the SciBooNE Hall using the Booster Neutrino Beam (BNB), and the SeaQuest experiment and Meson Test Beam (MTest) activities in the 120 GeV external Switchyard beam (SY120).

  9. Operational experience from a large EPICS-based accelerator facility

    SciTech Connect

    Ciarlette, D.J.; Gerig, R.

    1995-12-31

    The Advanced Photon Source (APS) at Argonne National Laboratory is a third-generation x-ray light source which uses the Experimental Physics and Industrial Control System (EPICS) to operate its linear accelerator, positron accumulator ring, booster synchrotron, and storage ring equipment. EPICS has been used at the APS since the beginning of installation and commissioning. Currently, EPICS controls approximately 100 VME crates containing over 100,000 process variables. With this complexity, the APS has had to review some of the methods originally employed and make changes as necessary. In addition, due to commissioning and operational needs, higher-level operator software needed to be created. EPICS has been flexible enough to allow this.

  10. Operational experience on the Brookhaven National Laboratory Accelerator Test Facility

    SciTech Connect

    Batchelor, K.; Babzien, M.; Ben-Zvi, I.

    1994-09-01

    Brookhaven National Laboratory Accelerator Test Facility is a laser-electron linear accelerator complex designed to provide high brightness beams for testing of advanced acceleration concepts and high power pulsed photon sources. Results of electron beam parameters attained during the commissioning of the nominally 45 MeV energy machine are presented.

  11. Operational experience for coupled operation of the Holifield tandem electrostatic accelerator and isochronous cyclotron

    SciTech Connect

    Martin, J.A.; Dowling, D.T.; Haynes, D.L.; Hudson, E.D.; Jones, C.M.; Juras, R.C.; Lane, S.S.; Ludemann, C.A.; Meigs, M.J.; Milner, W.T.

    1986-10-01

    Coupled operation of the 25 MV tandem accelerator and the Oak Ridge Isochronous Cyclotron of the Holifield Heavy Ion Research Facility began in January 1981. Since that time the use of the cyclotron in this mode has become routine. Thirty-six different ion species in the range from /sup 9/Be to /sup 150/Nd have been accelerated; 106 separate beam setups have been provided. Since the beginning of coupled operation, significant improvement of cyclotron systems, and setup and operating techniques, have been made. The graphite electrostatic deflector septum formerly used for high-current light ion beams has been replaced by a thin molybdenum septum. Extraction system positioning mechanisms have been refined and recalibrated and more precise and reliable position readouts have been provided. The computer-based control system has been improved. The frequency range of the rf system has been increased to eliminate an energy dead-band. Cyclotron setup calculations have been improved and standardized methods have been developed to consistently achieve well-centered orbits, correct beam extraction system positions, and electrostatic and magnetic strengths. A totally new beam bunching system has been installed. The improvements in the phase-lock system of the beam buncher have been especially effective. A large number of obsolete and unreliable power supplies have been replaced. Beam extraction efficiency has been increased from approx.50% to approx.70%. Accuracy of obtaining the desired energy without fine tuning is now approx.1% compared to 2 to 3% in early coupled operation. Beam setup time (tuning) has been reduced by approx.20%. Unscheduled maintenance has been reduced by a factor of two.

  12. Early operating experience with the Brookhaven National Laboratory radio frequency quadrupole accelerator

    SciTech Connect

    Brown, H.; Clifford, T.; Giordano, S.; Khiari, F.; McKenzie-Wilson, R.; Puglisi, M.; Warner, P.

    1984-05-01

    The Brookhaven National Laboratory polarized H/sup -/ injection program for the AGS utilizes a Radio Frequency Quadrupole (RFQ) for acceleration between the polarized H/sup -/ source and the Alvarez Linac. The RFQ accelerator is now in operation with low beam currents. The results of low and high power rf testing will be reported together with initial results of operation in the polarized H/sup -/ beam line.

  13. Construction, commissioning and operational experience of the Advanced Photon Source (APS) linear accelerator

    SciTech Connect

    White, M.; Arnold, N.; Berg, W.

    1996-10-01

    The Advanced Photon Source linear accelerator system consists of a 200 MeV, 2856 MHz S-Band electron linac and a 2-radiation-thick tungsten target followed by a 450 MeV positron linac. The linac system has operated 24 hours per day for the past year to support accelerator commissioning and beam studies and to provide beam for the user experimental program. It achieves the design goal for positron current of 8 mA and produces electron energies up to 650 MeV without the target in place. The linac is described and its operation and performance are discussed.

  14. Operation of the accelerator

    SciTech Connect

    Pardo, R.C.; Batzka, B.; Billquist, P.J.

    1995-08-01

    Fiscal Year 1994 was the first year of seven-day operation since ATLAS became a national user facility in 1985. ATLAS made the most of the opportunity this year by providing 5200 hours of beam on-target to the research program. A record number of 60 experiments were completed and the {open_quotes}facility reliability{close_quotes} remained near the 90% level. Seven-day operation was made possible with the addition to the staff of two operator positions providing single-operator coverage during the weekend period. The normally scheduled coverage was augmented by an on-call list of system experts who respond to emergencies with phone-in advice and return to the Laboratory when necessary. This staffing approach continues but we rearranged our staffing patterns so that we now have one cryogenics engineer working a shift pattern which includes 8-hour daily coverage during the weekend. ATLAS provided a beam mix to users consisting of 26 different isotopic species, 23% of which were for A>100 in FY 1994. Approximately 60% of the beam time was provided by the Positive Ion Injector, slightly less than the usage rate of FY 1993. Experiments using uranium or lead beams accounted for 16.4% of the total beam time. The ECR ion source and high-voltage platform functioned well throughout the year. A new technique for solid material production in the source was developed which uses a sputtering process wherein the sample of material placed near the plasma chamber wall is biased negatively. Plasma ions are accelerated into the sample and material is sputtered from the surface into the plasma. This technique is now used routinely for many elements. Runs of calcium, germanium, nickel, lead, tellurium, and uranium were carried out with this technique.

  15. Cw operation of the FMIT RFQ accelerator

    SciTech Connect

    Cornelius, W.D.

    1985-01-01

    Recently, we have achieved reliable cw operation of the Fusion Materials Irradiation Test (FMIT) radio-frequency quadrupole (RFQ) accelerator. In addition to the operational experiences in achieving this status, some of the modifications of the vacuum system, cooling system, and rf structure are discussed. Preliminary beam-characterization results are presented. 10 refs., 8 figs.

  16. Non-accelerator experiments

    SciTech Connect

    Goldhaber, M.

    1986-01-01

    This report discusses several topics which can be investigated without the use of accelerators. Topics covered are: (1) proton decay, (2) atmospheric neutrinos, (3) neutrino detection, (4) muons from Cygnus X-3, and (5) the double-beta decay.

  17. Operational experience at ELBE

    NASA Astrophysics Data System (ADS)

    Michel, P.; Lehnert, U.; Seidel, W.

    2015-05-01

    The ELBE center for high power radiation sources is the largest user facility in the Helmholtz-Zentrum Dresden- Rossendorf. The facility is based on a 36 MeV superconducting RF Linac which can be operated up to 1.6 mA in cw mode. The electron beam is used to generate secondary radiation, such as infrared light (Free Electron Lasers), coherent THz radiation, MeV-Bremsstrahlung, fast neutrons and positrons for a wide range of basic research like semiconductor physics, nuclear astrophysics and radio biological investigations. Two high power laser systems (500 TW Ti:Sa laser, 2 PW diode pumped laser) are under construction for laser acceleration experiments and X-ray generation by Thomson scattering. The FELs are in operation since 2004 (mid-IR FEL, 4-22μm) and 2006 (far-IF FEL, 20-250μm). The fundamental features of the ELBE IR FELs, the FEL instrumentation and advanced beam diagnostics for the photon beam are described. During ten years of user operation experiences and statistical data were collected.

  18. FXR accelerator cavity impedance experiments

    SciTech Connect

    Avalle, C.A.

    1998-01-05

    One of the goals of the present Flash X-Ray (FXR) accelerator upgrade effort [1][2] at Lawrence Livermore National Laboratory (LLNL) is to reduce the cavity transverse impedance, since it has been shown that beam stability is significantly affected by this parameter [3]. Recently, we have evaluated various techniques and cell modifications to accomplish that, both through lab measurements and computer models. A spare cell, identical in every way to cells in the accelerator, was specially modified for the experiments. The impedance measurements were done without the beam, by applying twin-wire techniques. This report describes the results of these experiments and suggests possible cell modifications to improve their performance. The techniques and modifications which are suggested might also be applicable to AHF and DARHT-2 long-pulse accelerator development.

  19. The FRC Acceleration Space Thruster (FAST) Experiment

    NASA Technical Reports Server (NTRS)

    Martin, Adam; Eskridge, Richard; Houts, Mike; Slough, John; Rodgers, Stephen L. (Technical Monitor)

    2002-01-01

    The objective of the FRC (Field Reversed Configuration) Acceleration Space Thruster (FAST) Experiment is to investigate the use of a repetitive FRC source as a thruster, specifically for an NEP (nuclear electric propulsion) system. The Field Reversed Configuration is a plasmoid with a closed poloidal field line structure, and has been extensively studied as a fusion reactor core. An FRC thruster works by repetitively producing FRCs and accelerating them to high velocity. An FRC thruster should be capable of I(sub sp)'s in the range of 5,000 - 25,000 seconds and efficiencies in the range of 60 - 80 %. In addition, they can have thrust densities as high as 10(exp 6) N/m2, and as they are inductively formed, they do not suffer from electrode erosion. The jet-power should be scalable from the low to the high power regime. The FAST experiment consists of a theta-pinch formation chamber, followed by an acceleration stage. Initially, we will produce and accelerate single FRCs. The initial focus of the experiment will be on the ionization, formation and acceleration of a single plasmoid, so as to determine the likely efficiency and I(sub sp). Subsequently, we will modify the device for repetitive burst-mode operation (5-10 shots). A variety of diagnostics are or will be available for this work, including a HeNe interferometer, high-speed cameras, and a Thomson-scattering system. The status of the experiment will be described.

  20. Accelerator physics experiments at Aladdin

    SciTech Connect

    Chattopadhyay, S.; Cornacchia, M.; Jackson, A.; Zisman, M.S.

    1985-07-01

    The Aladdin accelerator is a 1 GeV synchrotron light source located at the University of Wisconsin. The results of experimental studies of the Aladdin accelerator are described. The primary purpose of the experiments reported was to investigate reported anomalies in the behavior of the linear lattice, particularly in the vertical plane. A second goal was to estimate the ring broadband impedance. Experimental observations and interpretation of the linear properties of the Aladdin ring are described, including the beta function and dispersion measurements. Two experiments are described to measure the ring impedance, the first a measurement of the parasitic mode loss, and the second a measurement of the beam transfer function. Measurements of the longitudinal and transverse emittance at 100 and 200 MeV are described and compared with predictions. 10 refs., 24 figs., 2 tabs. (LEW)

  1. Deuterium accelerator experiments for APT.

    SciTech Connect

    Causey, Rion A. (Sandia National Laboratories, Livermore, CA); Hertz, Kristin L. (Sandia National Laboratories, Livermore, CA); Cowgill, Donald F. (Sandia National Laboratories, Livermore, CA)

    2005-08-01

    Sandia National Laboratories in California initiated an experimental program to determine whether tritium retention in the tube walls and permeation through the tubes into the surrounding coolant water would be a problem for the Accelerator Production of Tritium (APT), and to find ways to mitigate the problem, if it existed. Significant holdup in the tube walls would limit the ability of APT to meet its production goals, and high levels of permeation would require a costly cleanup system for the cooling water. To simulate tritium implantation, a 200 keV accelerator was used to implant deuterium into Al 6061-T and SS3 16L samples at temperatures and particle fluxes appropriate for APT, for times varying between one week and five months. The implanted samples were characterized to determine the deuterium retention and Permeation. During the implantation, the D(d,p)T nuclear reaction was used to monitor the build-up of deuterium in the implant region of the samples. These experiments increased in sophistication, from mono-energetic deuteron implants to multi-energetic deuteron and proton implants, to more accurately reproduce the conditions expected in APT. Micron-thick copper, nickel, and anodized aluminum coatings were applied to the front surface of the samples (inside of the APT walls) in an attempt to lower retention and permeation. The reduction in both retention and permeation produced by the nickel coatings, and the ability to apply them to the inside of the APT tubes, indicate that both nickel-coated Al 6061-T6 and nickel-coated SS3 16L tubes would be effective for use in APT. The results of this work were submitted to the Accelerator Production of Tritium project in document number TPO-E29-Z-TNS-X-00050, APT-MP-01-17.

  2. REMOTE OPERATIONS IN A GLOBAL ACCELERATOR NETWORK.

    SciTech Connect

    PEGGS,S.; SATOGATA,T.; AGARWAL,D.; RICE,D.

    2003-05-12

    The INTRODUCTION to this paper summarizes the history of the Global Accelerator Network (GAN) concept and the recent workshops that discussed the relationship between GAN and Remote Operations. The REMOTE OPERATIONS SCENARIOS section brings out the organizational philosophy embodied in GAN-like and to non-GAN-like scenarios. The set of major TOPICS RAISED AT THE WORKSHOPS are only partially resolved. COLLABORATION TOOLS are described and discussed, followed by examples of REMOTE ACCELERATOR CONTROL PROJECTS around the world.

  3. REMOTE OPERATIONS IN A GLOBAL ACCELERATOR NETWORK

    SciTech Connect

    PEGGS,S.SATOGATA,TAGARWAL,DRICE,D

    2003-05-12

    The INTRODUCTION to this paper summarizes the history of the Global Accelerator Network (GAN) concept and the recent workshops that discussed the relationship between GAN and Remote Operations. The REMOTE OPERATIONS SCENARIOS section brings out the organizational philosophy embodied in GAN-like and to non-GAN-like scenarios. The set of major TOPICS RAISED AT THE WORKSHOPS are only partially resolved. COLLABORATION TOOLS are described and discussed, followed by examples of REMOTE ACCELERATOR CONTROL PROJECTS around the world.

  4. Remote operations in a global accelerator network

    SciTech Connect

    Peggs, Steve; Satogata, Todd; Agarwal, Deborah; Rice, David

    2003-05-08

    The INTRODUCTION to this paper summarizes the history of the Global Accelerator Network (GAN) concept and the recent workshops that discussed the relationship between GAN and Remote Operations. The REMOTE OPERATIONS SCENARIOS section brings out the organizational philosophy embodied in GAN-like and to non-GAN-like scenarios. The set of major TOPICS RAISED AT THE WORKSHOPS are only partially resolved. COLLABORATION TOOLS are described and discussed, followed by examples of REMOTE ACCELERATOR CONTROL PROJECTS around the world.

  5. Fermilab SRF cryomodule operational experience

    SciTech Connect

    Martinez, A.; Klebaner, A.L.; Theilacker, J.C.; DeGraff, B.D.; White, M.; Johnson, G.S.; /Fermilab

    2011-06-01

    Fermi National Accelerator Laboratory is constructing an Advanced Accelerator Research and Development facility at New Muon Lab. The cryogenic infrastructure in support of the initial phase of the facility consists of two Tevatron style standalone refrigerators, cryogenic distribution system as well as an ambient temperature pumping system to achieve 2K operations with supporting purification systems. During this phase of the project a single Type III plus 1.3 GHz cryomodule was installed, cooled and tested. Design constraints of the cryomodule required that the cryomodule individual circuits be cooled at predetermined rates. These constraints required special design solutions to achieve. This paper describes the initial cooldown and operational experience of a 1.3 GHz cryomodule using the New Muon Lab cryogenic system.

  6. Stirling machine operating experience

    NASA Technical Reports Server (NTRS)

    Ross, Brad; Dudenhoefer, James E.

    1991-01-01

    Numerous Stirling machines have been built and operated, but the operating experience of these machines is not well known. It is important to examine this operating experience in detail, because it largely substantiates the claim that Stirling machines are capable of reliable and lengthy lives. The amount of data that exists is impressive, considering that many of the machines that have been built are developmental machines intended to show proof of concept, and were not expected to operate for any lengthy period of time. Some Stirling machines (typically free-piston machines) achieve long life through non-contact bearings, while other Stirling machines (typically kinematic) have achieved long operating lives through regular seal and bearing replacements. In addition to engine and system testing, life testing of critical components is also considered.

  7. Magnet operating experience review for fusion applications

    SciTech Connect

    Cadwallader, L.C.

    1991-11-01

    This report presents a review of magnet operating experiences for normal-conducting and superconducting magnets from fusion, particle accelerator, medical technology, and magnetohydrodynamics research areas. Safety relevant magnet operating experiences are presented to provide feedback on field performance of existing designs and to point out the operational safety concerns. Quantitative estimates of magnet component failure rates and accident event frequencies are also presented, based on field experience and on performance of similar components in other industries.

  8. Development of wide area environment accelerator operation and diagnostics method

    NASA Astrophysics Data System (ADS)

    Uchiyama, Akito; Furukawa, Kazuro

    2015-08-01

    Remote operation and diagnostic systems for particle accelerators have been developed for beam operation and maintenance in various situations. Even though fully remote experiments are not necessary, the remote diagnosis and maintenance of the accelerator is required. Considering remote-operation operator interfaces (OPIs), the use of standard protocols such as the hypertext transfer protocol (HTTP) is advantageous, because system-dependent protocols are unnecessary between the remote client and the on-site server. Here, we have developed a client system based on WebSocket, which is a new protocol provided by the Internet Engineering Task Force for Web-based systems, as a next-generation Web-based OPI using the Experimental Physics and Industrial Control System Channel Access protocol. As a result of this implementation, WebSocket-based client systems have become available for remote operation. Also, as regards practical application, the remote operation of an accelerator via a wide area network (WAN) faces a number of challenges, e.g., the accelerator has both experimental device and radiation generator characteristics. Any error in remote control system operation could result in an immediate breakdown. Therefore, we propose the implementation of an operator intervention system for remote accelerator diagnostics and support that can obviate any differences between the local control room and remote locations. Here, remote-operation Web-based OPIs, which resolve security issues, are developed.

  9. Magnetically accelerated foils for shock wave experiments

    NASA Astrophysics Data System (ADS)

    Neff, Stephan; Ford, Jessica; Martinez, David; Plechaty, Christopher; Wright, Sandra; Presura, Radu

    2008-04-01

    The interaction of shock waves with inhomogeneous media is important in many astrophysical problems, e.g. the role of shock compression in star formation. Using scaled experiments with inhomogeneous foam targets makes it possible to study relevant physics in the laboratory, to better understand the mechanisms of shock compression and to benchmark astrophysical simulation codes. Experiments with flyer-generated shock waves have been performed on the Z machine in Sandia. The Zebra accelerator at the Nevada Terawatt Facility (NTF) allows for complementary experiments with high repetition rate. First experiments on Zebra demonstrated flyer acceleration to sufficiently high velocities (around 2 km/s) and that laser shadowgraphy can image sound fronts in transparent targets. Based on this, we designed an optimized setup to improve the flyer parameters (higher speed and mass) to create shock waves in transparent media. Once x-ray backlighting with the Leopard laser at NTF is operational, we will switch to foam targets with parameters relevant for laboratory astrophysics.

  10. Pulsed Operation of an Ion Accelerator

    NASA Technical Reports Server (NTRS)

    Wirz, Richard; Gamero-Castano, Manuel; Goebel, Dan

    2009-01-01

    Electronic circuitry has been devised to enable operation of an ion accelerator in either a continuous mode or a highpeak power, low-average-power pulsed mode. In the original intended application, the ion accelerator would be used as a spacecraft thruster and the pulse mode would serve to generate small increments of impulse for precise control of trajectories and attitude. The present electronic drive circuitry generates the extraction voltage in pulses. Pulse-width modulation can affect rapid, fine control of time-averaged impulse or ion flux down to a minimum level much lower than that achievable in continuous operation.

  11. Experiment specific processing of residual acceleration data

    NASA Technical Reports Server (NTRS)

    Rogers, Melissa J. B.; Alexander, J. I. D.

    1992-01-01

    To date, most Spacelab residual acceleration data collection projects have resulted in data bases that are overwhelming to the investigator of low-gravity experiments. This paper introduces a simple passive accelerometer system to measure low-frequency accelerations. Model responses for experiments using actual acceleration data are produced and correlations are made between experiment response and the accelerometer time history in order to test the idea that recorded acceleration data and experimental responses can be usefully correlated. Spacelab 3 accelerometer data are used as input to a variety of experiment models, and sensitivity limits are obtained for particular experiment classes. The modeling results are being used to create experiment-specific residual acceleration data processing schemes for interested investigators.

  12. Stirling machine operating experience

    SciTech Connect

    Ross, B.; Dudenhoefer, J.E.

    1994-09-01

    Numerous Stirling machines have been built and operated, but the operating experience of these machines is not well known. It is important to examine this operating experience in detail, because it largely substantiates the claim that stirling machines are capable of reliable and lengthy operating lives. The amount of data that exists is impressive, considering that many of the machines that have been built are developmental machines intended to show proof of concept, and are not expected to operate for lengthy periods of time. Some Stirling machines (typically free-piston machines) achieve long life through non-contact bearings, while other Stirling machines (typically kinematic) have achieved long operating lives through regular seal and bearing replacements. In addition to engine and system testing, life testing of critical components is also considered. The record in this paper is not complete, due to the reluctance of some organizations to release operational data and because several organizations were not contacted. The authors intend to repeat this assessment in three years, hoping for even greater participation.

  13. Space Experiments with Particle Accelerators (SEPAC)

    NASA Technical Reports Server (NTRS)

    Roberts, W. T.

    1985-01-01

    The space experiments with particle accelerators (SEPAC) instruments consist of an electron accelerator, a plasma accelerator, a neutral gas (N2) release device, particle and field diagnostic instruments, and a low light level television system. These instruments are used to accomplish multiple experiments: to study beam particle interactions and other plasma processes; as probes to investigate magnetospheric processes; and as perturbation devices to study energy coupling mechanisms in the magnetosphere, ionosphere, and upper atmosphere.

  14. SLAC accelerator operations report: 1992-1995

    SciTech Connect

    Erickson, R.; Allen, C.W.; Inman, T.K.; Linebarger, W.; Stanek, M.

    1995-05-01

    Operational statistics for the linear accelerator programs at SLAC are presented, including run-time records for the SLC, FFTB, and fixed target programs. Also included are summaries of reliability and maintenance-related statistics and a discussion of the analysis tools used to study error messages generated by the control system.

  15. Space Experiments with Particle Accelerators (SEPAC)

    NASA Technical Reports Server (NTRS)

    Obayashi, T.; Kawashima, N.; Kuriki, K.; Nagatomo, M.; Ninomiya, K.; Sasaki, S.; Ushirokawa, A.; Kudo, I.; Ejiri, M.; Roberts, W. T.

    1982-01-01

    Plans for SEPAC, an instrument array to be used on Spacelab 1 to study vehicle charging and neutralization, beam-plasma interaction in space, beam-atmospheric interaction exciting artificial aurora and airglow, and the electromagnetic-field configuration of the magnetosphere, are presented. The hardware, consisting of electron beam accelerator, magnetoplasma arcjet, neutral-gas plume generator, power supply, diagnostic package (photometer, plasma probes, particle analyzers, and plasma-wave package), TV monitor, and control and data-management unit, is described. The individual SEPAC experiments, the typical operational sequence, and the general outline of the SEPAC follow-on mission are discussed. Some of the experiments are to be joint ventures with AEPI (INS 003) and will be monitored by low-light-level TV.

  16. Magnetically accelerated foils for shock wave experiments

    NASA Astrophysics Data System (ADS)

    Neff, S.; Ford, J.; Wright, S.; Martinez, D.; Plechaty, C.; Presura, R.

    2009-08-01

    Many astrophysical phenomena involve the interaction of a shock wave with an inhomogeneous background medium. Using scaled experiments with inhomogeneous foam targets makes it possible to study relevant physics in the laboratory to better understand the mechanisms of shock compression and to benchmark astrophysical simulation codes. First experiments on Zebra at the Nevada Terawatt Facility (NTF) have demonstrated flyer acceleration to sufficiently high velocities (up to 5 km/s) and that laser shadowgraphy can image sound fronts in transparent targets. Based on this, we designed an optimized setup to improve the flyer parameters (higher speed and mass) to create shock waves in transparent media. Once x-ray backlighting with the Leopard laser at NTF is operational, we will switch to foam targets with parameters relevant for laboratory astrophysics.

  17. Inverse Cerenkov laser acceleration experiment at ATF

    NASA Astrophysics Data System (ADS)

    Wang, X. J.; Pogorelsky, I.; Fernow, R.; Kusche, K. P.; Liu, Y.; Kimura, W. D.; Kim, G. H.; Romea, R. D.; Steinhauer, L. C.

    Inverse Cerenkov laser acceleration was demonstrated using an axicon optical system at the Brookhaven Accelerator Test Facility (ATF). The ATF S-band linac and a high power 10.6 MICROMETERSCO2 laser were used for the experiment. Experimental arrangement and the laser and the electron beams synchronization are discussed. The electrons were accelerated more than 0.7 MeV for a 34 MW CO2 laser power. More than 3.7 MeV acceleration was measured with 0.7 GW CO2 laser power, which is more than 20 times of the previous ICA experiment. The experimental results are compared with computer program TRANSPORT simulations.

  18. HIGH POWER OPERATIONS AT THE LOW ENERGY DEMONSTRATION ACCELERATOR (LEDA)

    SciTech Connect

    M. DURAN; V. R. HARRIS

    2001-01-01

    Recently, the Low-Energy Demonstration Accelerator (LEDA) portion of the Accelerator Production of Tritium (APT) project reached its 100-mA, 8-hr continuous wave (CW) beam operation milestone. The LEDA accelerator is a prototype of the low-energy front-end of the linear accelerator (linac) that would have been used in an APT plant. LEDA consists of a 75-keV proton injector, 6.7-MeV, 350-MHz CW radio-frequency quadrupole (RFQ) with associated high-power and low-level RF systems, a short high-energy beam transport (HEBT) and high-power (670-kW CW) beam dump. Details of the LEDA design features will be discussed along with the operational health physics experiences that occurred during the LEDA commissioning phase.

  19. White Cliffs: Operating Experience

    NASA Technical Reports Server (NTRS)

    Kaneff, S.

    1984-01-01

    The fourteen dish white cliffs solar power station area is remote and subject to extreme environmental conditions, solution of the associated problems required careful and thoughtful attention and the application of resources. Notwithstanding the wide range and harshness of conditions, the difficulties caused by remoteness and the lack of a technological base and the need for relatively rapid demonstration of success, the project has had a very positive outcome. Qualitative and quantitative information and lessons are now available to enable considerable simplifications to be made for a new system, reducing both hardware and operation and maintenance costs. Experience and lessons are presented, particularly in relation to: system performance in various environmental conditions; design philosophies for collectors, the array, control systems, engine and plant; operation and maintenance strategies and cost reducing possibilities. Experience so far gives encouragement for the future of such paraboloidal dish systems in appropriate areas.

  20. GNF2 Operating Experience

    SciTech Connect

    Schardt, John

    2007-07-01

    GNF's latest generation fuel product, GNF2, is designed to deliver improved nuclear efficiency, higher bundle and cycle energy capability, and more operational flexibility. But along with high performance, our customers face a growing need for absolute fuel reliability. This is driven by a general sense in the industry that LWR fuel reliability has plateaued. Too many plants are operating with fuel leakers, and the impact on plant operations and operator focus is unacceptable. The industry has responded by implementing an INPO-coordinated program aimed at achieving leaker-free reliability by 2010. One focus area of the program is the relationship between fuel performance (i.e., duty) and reliability. The industry recognizes that the right balance between performance and problem-free fuel reliability is critical. In the development of GNF2, GNF understood the requirement for a balanced solution and utilized a product development and introduction strategy that specifically addressed reliability: evolutionary design features supported by an extensive experience base; thoroughly tested components; and defense-in-depth mitigation of all identified failure mechanisms. The final proof test that the balance has been achieved is the application of the design, initially through lead use assemblies (LUAs), in a variety of plants that reflect the diversity of the BWR fleet. Regular detailed surveillance of these bundles provides the verification that the proper balance between performance and reliability has been achieved. GNF currently has GNF2 lead use assemblies operating in five plants. Included are plants that have implemented extended power up-rates, plants on one and two-year operating cycles, and plants with and without NobleChem{sup TM} and zinc injection. The leading plant has undergone three pool-side inspections outages to date. This paper reviews the actions taken to insure GNF2's reliability, and the lead use assembly surveillance data accumulated to date to

  1. Laboratory Reconnection Experiments - heating and particle acceleration

    NASA Astrophysics Data System (ADS)

    Ono, Yasushi

    Recent laboratory merging/ reconnection experiments have solved a number of key physics of magnetic reconnection: 1) reconnection heating/ acceleration, 2) fast reconnection mechanisms, 3) plasmoid reconnection, 4) non-steady reconnection and 5) non-thermal particle acceleration using new kinetic interpretations. Especially, significant ion temperatures 1.2keV were documented in the world-largest tokamak merging experiment: MAST after detailed 2D elucidation of ion and electron heating characteristics in TS-3 and 4 merging experiments. The measured 2D contours of ion and electron temperatures in TS-3, 4 and MAST reveal ion heating in the downstream by reconnection outflow and electron heating around the X-point by ohmic heating of current sheet. Their detailed heating mechanisms were further investigated by comparing those results with particle simulations developed by NIFS. The ion acceleration mechanism is mostly parallel acceleration by reconnection electric field and partly perpendicular acceleration by electrostatic potential. The fast shock and ion viscosity are the major dumping (heating) mechanisms for the accelerated ions. We successfully applied the reconnection heating - typically 10-50MW to the high-beta spherical tokamak formation and heating. This paper will review major progresses in those international and interdisciplinary merging tokamak experiments.

  2. Isentropic Compression Experiments on the Z Accelerator

    NASA Astrophysics Data System (ADS)

    Asay, James

    1999-06-01

    Shock compression techniques are the only viable technique for making accurate EOS measurements in the multi-Mbar pressure regime. These experiments provide specific states of pressure, volume and internal energy on the Hugoniot. In many applications, it is necessary to know the off-Hugoniot isentropic loading response of materials to ultra-high pressures. Techniques for measuring isentropic response are challenging. At low pressures, ramp wave generators are used, while at high megabar pressures, graded density impactors are employed. In these latter experiments is a small amplitude shock results in the compression isentrope centered at some initial state. A new technique that is being developed shows promise for performing isentropic experiments with smooth loading to very high pressure. This approach uses the high current densities produced with fast pulsed power accelerators to create continuous magnetic loading to a few hundred kilobars over time intervals of 100-200 ns. The resulting ramp wave propagates through a planar specimen and are measured using time-resolved VISARS. Application of the differential equations of motion over the risetime of the waves determines pressure-volume states continuously. Experiments on copper and iron, have allowed determination of the isentropic compression curve in copper and the evaluation of the kinetic properties of the alpha-epsilon phase transition in iron. In this presentation, I will review previous studies of isentropic compression, discuss the new technique using Z and the results obtained on iron and copper. A perspective on the opportunities for isentropic compression experiments to multi-Mbar pressures, will be given. * Sandia is a multi-program laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under Contract DE-AC04-94AL8500.

  3. Accelerated Application Development: The ORNL Titan Experience

    SciTech Connect

    Joubert, Wayne; Archibald, Richard K.; Berrill, Mark A.; Brown, W. Michael; Eisenbach, Markus; Grout, Ray; Larkin, Jeff; Levesque, John; Messer, Bronson; Norman, Matthew R.; Philip, Bobby; Sankaran, Ramanan; Tharrington, Arnold N.; Turner, John A.

    2015-05-09

    The use of computational accelerators such as NVIDIA GPUs and Intel Xeon Phi processors is now widespread in the high performance computing community, with many applications delivering impressive performance gains. However, programming these systems for high performance, performance portability and software maintainability has been a challenge. In this paper we discuss experiences porting applications to the Titan system. Titan, which began planning in 2009 and was deployed for general use in 2013, was the first multi-petaflop system based on accelerator hardware. To ready applications for accelerated computing, a preparedness effort was undertaken prior to delivery of Titan. In this paper we report experiences and lessons learned from this process and describe how users are currently making use of computational accelerators on Titan.

  4. Accelerated Application Development: The ORNL Titan Experience

    DOE PAGESBeta

    Joubert, Wayne; Archibald, Richard K.; Berrill, Mark A.; Brown, W. Michael; Eisenbach, Markus; Grout, Ray; Larkin, Jeff; Levesque, John; Messer, Bronson; Norman, Matthew R.; et al

    2015-05-09

    The use of computational accelerators such as NVIDIA GPUs and Intel Xeon Phi processors is now widespread in the high performance computing community, with many applications delivering impressive performance gains. However, programming these systems for high performance, performance portability and software maintainability has been a challenge. In this paper we discuss experiences porting applications to the Titan system. Titan, which began planning in 2009 and was deployed for general use in 2013, was the first multi-petaflop system based on accelerator hardware. To ready applications for accelerated computing, a preparedness effort was undertaken prior to delivery of Titan. In this papermore » we report experiences and lessons learned from this process and describe how users are currently making use of computational accelerators on Titan.« less

  5. Inverse Cerenkov laser acceleration experiment at ATF

    SciTech Connect

    Wang, X.J.; Pogorelsky, I.; Fernow, R.; Kusche, K.P.; Liu, Y.; Kimura, W.D.; Kim, G.H.; Romea, R.D.; Steinhauer, L.C.

    1994-09-01

    Inverse Cerenkov laser acceleration was demonstrated using an axicon optical system at the Brookhaven Accelerator Test Facility (ATF). The ATF S-band linac and a high power 10.6 {mu}m CO{sub 2} laser were used for the experiment. Experimental arrangement and the laser and the electron beams synchronization are discussed. The electrons were accelerated more than 0.7 MeV for a 34 MW CO{sub 2} laser power. More than 3.7 MeV acceleration was measured with 0.7 GW CO{sub 2} laser power, which is more than 20 times of the previous ICA experiment. The experimental results are compared with computer program TRANSPORT simulations.

  6. Energy deposition via magnetoplasmadynamic acceleration: I. Experiment

    NASA Astrophysics Data System (ADS)

    Gilland, James; Mikellides, Pavlos; Marriott, Darin

    2009-02-01

    The expansion of a high-temperature fusion plasma through an expanding magnetic field is a process common to most fusion propulsion concepts. The propulsive efficiency of this process has a strong bearing on the overall performance of fusion propulsion. In order to simulate the expansion of a fusion plasma, a concept has been developed in which a high velocity plasma is first stagnated in a converging magnetic field to high (100s of eV) temperatures, then expanded though a converging/diverging magnetic nozzle. As a first step in constructing this experiment, a gigawatt magnetoplasmadynamic plasma accelerator was constructed to generate the initial high velocity plasma and has been characterized. The source is powered by a 1.6 MJ, 1.6 ms pulse forming network. The device has been operated with currents up to 300 kA and power levels up to 200 MWe. These values are among the highest levels reached in an magnetoplasmadynamic thruster. The device operation has been characterized by quasi-steady voltage and current measurements for helium mass flow rates from 0.5 to 27 g s-1. Probe results for downstream plasma density and electron temperature are also presented. The source behavior is examined in terms of current theories for magnetoplasmadynamic thrusters.

  7. Space experiments with particle accelerators: SEPAC

    NASA Technical Reports Server (NTRS)

    Roberts, B.

    1986-01-01

    The SEPAC instruments consist of an electron accelerator, a plasma accelerator, a neutral gas (N2) release device, particle and field diagnostic instruments, and a low light level television system. These instruments are used to accomplish multiple experiments: to study beam-particle interactions and other plasma processes; as probes to investigate magnetospheric processes; and as perturbation devices to study energy coupling mechanisms in the magnetosphere, ionosphere, and upper atmosphere.

  8. Estimates of effects of residual acceleration on USML-1 experiments

    NASA Technical Reports Server (NTRS)

    Naumann, Robert J.

    1995-01-01

    The purpose of this study effort was to develop analytical models to describe the effects of residual accelerations on the experiments to be carried on the first U.S. Microgravity Lab mission (USML-1) and to test the accuracy of these models by comparing the pre-flight predicted effects with the post-flight measured effects. After surveying the experiments to be performed on USML-1, it became evident that the anticipated residual accelerations during the USML-1 mission were well below the threshold for most of the primary experiments and all of the secondary (Glovebox) experiments and that the only set of experiments that could provide quantifiable effects, and thus provide a definitive test of the analytical models, were the three melt growth experiments using the Bridgman-Stockbarger type Crystal Growth Furnace (CGF). This class of experiments is by far the most sensitive to low level quasi-steady accelerations that are unavoidable on space craft operating in low earth orbit. Because of this, they have been the drivers for the acceleration requirements imposed on the Space Station. Therefore, it is appropriate that the models on which these requirements are based are tested experimentally. Also, since solidification proceeds directionally over a long period of time, the solidified ingot provides a more or less continuous record of the effects from acceleration disturbances.

  9. SIMULATING ACCELERATOR STRUCTURE OPERATION AT HIGH POWER

    SciTech Connect

    Ivanov, V

    2004-09-15

    The important limiting factors in high-gradient accelerator structure operation are dark current capture, RF breakdown and electron multipacting. These processes involve both primary and secondary electron field emission and produce plasma and X-rays. To better understand these phenomena, they have simulated dark current generation and transport in a linac structure and a square-bend waveguide, both high power tested at SLAC. For these simulations, they use the parallel, time-domain, unstructured-grid code Tau3P and the particle tracking module Track3P. In this paper, they present numerical results and their comparison with measurements on energy spectrum of electrons transmitted in a 30-cell structure and of X-rays emitted from the square-bend waveguide.

  10. Tevatron accelerator physics and operation highlights

    SciTech Connect

    Valishev, A.; /Fermilab

    2011-03-01

    The performance of the Tevatron collider demonstrated continuous growth over the course of Run II, with the peak luminosity reaching 4 x 10{sup 32} cm{sup -2} s{sup -1}, and the weekly integration rate exceeding 70 pb{sup -1}. This report presents a review of the most important advances that contributed to this performance improvement, including beam dynamics modeling, precision optics measurements and stability control, implementation of collimation during low-beta squeeze. Algorithms employed for optimization of the luminosity integration are presented and the lessons learned from high-luminosity operation are discussed. Studies of novel accelerator physics concepts at the Tevatron are described, such as the collimation techniques using crystal collimator and hollow electron beam, and compensation of beam-beam effects.

  11. Diagnostics for advanced laser acceleration experiments

    SciTech Connect

    Misuri, Alessio

    2002-06-01

    The first proposal for plasma based accelerators was suggested by 1979 by Tajima and Dawson. Since then there has been a tremendous progress both theoretically and experimentally. The theoretical progress is particularly due to the growing interest in the subject and to the development of more accurate numerical codes for the plasma simulations (especially particle-in-cell codes). The experimental progress follows from the development of multi-terawatt laser systems based on the chirped-pulse amplification technique. These efforts have produced results in several experiments world-wide, with the detection of accelerated electrons of tens of MeV. The peculiarity of these advanced accelerators is their ability to sustain extremely large acceleration gradients. In the conventional radio frequency linear accelerators (RF linacs) the acceleration gradients are limited roughly to 100 MV/m; this is partially due to breakdown which occurs on the walls of the structure. The electrical breakdown is originated by the emission of the electrons from the walls of the cavity. The electrons cause an avalanche breakdown when they reach other metal parts of the RF linacs structure.

  12. Space Experiments with Particle Accelerators (SEPAC)

    NASA Technical Reports Server (NTRS)

    Obayashi, Tatsuzo

    1988-01-01

    The purpose of Space Experiments with Particle Accelerators (SEPAC) on the Atmospheric Laboratory for Applications and Science (ATLAS 1) mission, is to carry out active and interactive experiments on and in the earth's ionosphere, atmosphere, and magnetosphere. The instruments to be used are an electron beam accelerator (EBA), plasma contactor, and associated instruments the purpose of which is to perform diagnostic, monitoring, and general data taking functions. Four major classes of investigations are to be performed by SEPAC. They are: beam plasma physics, beam-atmosphere interactions, the use of modulated electron beams as transmitting antennas, and the use of electron beams for remote sensing of electric and magnetic fields. The first class consists mainly of onboard plasma physics experiments to measure the effects of phenomena in the vicinity of the shuttle. The last three are concerned with remote effects and are supported by other ATLAS 1 investigations as well as by ground-based observations.

  13. Space experiments with particle accelerators. [Spacelab

    NASA Technical Reports Server (NTRS)

    Obayashi, T.

    1981-01-01

    The purpose of space experiments with particle accelerators (SEPAC) is to carry out active and interactive experiments on and in the Earth's ionosphere and magnetosphere. It is also intended to make an initial performance test for an overall program of Spacelab/SEPAC experiments. The instruments to be used are an electron beam accelerator, magnetoplasma dynamic arcjet, and associated diagnostic equipment. The accelerators are installed on the pallet, with monitoring and diagnostic observations being made by the gas plume release, beam-monitor TV, and particle-wave measuring instruments also mounted on the pallet. Command and display systems are installed in the module. Three major classes of investigations to be performed are vehicle charge neutralization, beam plasma physics, and beam atmosphere interactions. The first two are mainly onboard plasma physics experiments to measure the effect of phenomena in the vicinity of Spacelab. The last one is concerned with atmospheric modification and is supported by other Spacelab 1 investigations as well as by ground-based, remote sensing observations.

  14. Orbital Acceleration Research Experiment: Calibration Measurements

    NASA Technical Reports Server (NTRS)

    Blanchard, Robert C.; Nicholson, John Y.; Ritter, James R.; Larman, Kevin T.

    1995-01-01

    The Orbital Acceleration Research Experiment (OARE), which has flown on STS-40, STS-50, and STS-58, contains a three-axis accelerometer with a single, nonpendulous, electrostatically suspended proofmass, which can resolve accelerations to the 10(sub -9) g level. The experiment also contains a full calibration station to permit in situ bias and scale-factor calibration. This on-orbit calibration capability eliminates the large uncertainty of ground-based calibrations encountered with accelerometers flown in the past on the Orbiter, and thus provides absolute acceleration measurement accuracy heretofore unachievable. This is the first time accelerometer scale-factor measurements have been performed on orbit. A detailed analysis of the calibration process is given, along with results of the calibration factors from the on-orbit OARE flight measurements on STS-58. In addition, the analysis of OARE flight-maneuver data used to validate the scale-factor measurements in the sensor's most sensitive range are also presented. Estimates on calibration uncertainties are discussed. These uncertainty estimates provides bounds on the STS-58 absolute acceleration measurements for future applications.

  15. Droplet Combustion Experiment Operates

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Fuel ignites and burns in the Droplet Combustion Experiment (DCE) on STS-94 on July 12, 1997, MET:11/07:00 (approximate). DCE used various fuels -- in drops ranging from 1 mm (0.04 inches) to 5 mm (0.2 inches) -- and mixtures of oxidizers and inert gases to learn more about the physics of combustion in the simplest burning configuration, a sphere. The DCE was designed to investigate the fundamental combustion aspects of single, isolated droplets under different pressures and ambient oxygen concentrations for a range of droplet sizes varying between 2 and 5 mm. The experiment elapsed time is shown at the bottom of the composite image. The DCE principal investigator was Forman Williams, University of California, San Diego. The experiment was part of the space research investigations conducted during the Microgravity Science Laboratory-1R mission (STS-94, July 1-17 1997). Advanced combustion experiments will be a part of investigations plarned for the International Space Station. (119KB JPEG, 658 x 982 pixels; downlinked video, higher quality not available) The MPG from which this composite was made is available at http://mix.msfc.nasa.gov/ABSTRACTS/MSFC-0300171.html.

  16. Space Experiments with Particle Accelerators: SEPAC

    NASA Technical Reports Server (NTRS)

    Burch, J. L.; Roberts, W. T.; Taylor, W. W. L.; Kawashima, N.; Marshall, J. A.; Moses, S. L.; Neubert, T.; Mende, S. B.; Choueiri, E. Y.

    1994-01-01

    The Space Experiments with Particle Accelerators (SEPAC), which flew on the Atmospheric Laboratory for Applications and Science (ATLAS) 1 mission, used new techniques to study natural phenomena in the Earth's upper atmosphere, ionosphere and magnetosphere by introducing energetic perturbations into the system from a high power electron beam with known characteristics. Properties of auroras were studied by directing the electron beam into the upper atmosphere while making measurements of optical emissions. Studies were also performed of the critical ionization velocity phenomenon.

  17. Accelerator-based neutrino oscillation experiments

    SciTech Connect

    Harris, Deborah A.; /Fermilab

    2007-12-01

    Neutrino oscillations were first discovered by experiments looking at neutrinos coming from extra-terrestrial sources, namely the sun and the atmosphere, but we will be depending on earth-based sources to take many of the next steps in this field. This article describes what has been learned so far from accelerator-based neutrino oscillation experiments, and then describe very generally what the next accelerator-based steps are. In section 2 the article discusses how one uses an accelerator to make a neutrino beam, in particular, one made from decays in flight of charged pions. There are several different neutrino detection methods currently in use, or under development. In section 3 these are presented, with a description of the general concept, an example of such a detector, and then a brief discussion of the outstanding issues associated with this detection technique. Finally, section 4 describes how the measurements of oscillation probabilities are made. This includes a description of the near detector technique and how it can be used to make the most precise measurements of neutrino oscillations.

  18. The LHCf experiment at the LHC accelerator

    SciTech Connect

    Bonechi, L.; Adriani, O.; Bongi, M.; D'Alessandro, R.; Papini, P.; Castellini, G.; Faus, A.; Velasco, J.; Haguenauer, M.; Itow, Y.; Mase, T.; Masuda, K.; Matsubara, Y.; Matsumoto, H.; Menjo, H.; Muraki, Y.; Sako, T.; Tanaka, K.; Watanabe, H.; Kasahara, K.

    2006-10-27

    The claimed discovery of atmospheric shower induced by cosmic-ray with energy beyond the GZK cutoff by the AGASA experiment in 1994-1995, although not confirmed by other important experiments like Fly's Eye and Hi-Res, together with the poor knowledge of the composition of cosmic rays around and beyond the Knee region, have highlighted the necessity of new experiments that should increase our present knowledge of HECR and UHECR. For this reason big efforts have been addressed to the development of new experiments, like Auger, TA and EUSO, for a systematic study of the UHE atmospheric showers with increased capabilities with respect to the previous experiments. Moreover complementary experiments should allow a precise calibration of the methods used for the reconstruction of cosmic-ray showers in atmosphere. Their aim is the measurement of quantities that are used in these procedures and that are not yet precisely known. Under this perspective the LHCf experiment is a compact experiment which has been proposed for the study of neutral pion and gamma production at high energy in proton-proton interaction in the very forward region of the LHC accelerator. It will help calibrating the algorithms that are used to reconstruct the atmospheric shower events for energy beyond the Knee. The LHCf apparatus and the results of the first beam test, held in 2004, are shortly discussed in this work.

  19. Choosing experiments to accelerate collective discovery

    SciTech Connect

    Rzhetsky, Andrey; Foster, Jacob G.; Foster, Ian T.; Evans, James A.

    2015-11-24

    Scientists perform a tiny subset of all possible experiments. What characterizes the experiments they choose? What are the consequences of those choices for the pace of scientific discovery? We model scientific knowledge as a network and science as a sequence of experiments designed to gradually uncover it. By analyzing millions of biomedical articles published over 30 y, we find that biomedical scientists pursue conservative research strategies exploring the local neighborhood of central, important molecules. Although such strategies probably serve scientific careers, we show that they slow scientific advance, especially in mature fields, where more risk and less redundant experimentation would accelerate discovery of the network. Lastly, we also consider institutional arrangements that could help science pursue these more efficient strategies.

  20. Choosing experiments to accelerate collective discovery

    DOE PAGESBeta

    Rzhetsky, Andrey; Foster, Jacob G.; Foster, Ian T.; Evans, James A.

    2015-11-24

    Scientists perform a tiny subset of all possible experiments. What characterizes the experiments they choose? What are the consequences of those choices for the pace of scientific discovery? We model scientific knowledge as a network and science as a sequence of experiments designed to gradually uncover it. By analyzing millions of biomedical articles published over 30 y, we find that biomedical scientists pursue conservative research strategies exploring the local neighborhood of central, important molecules. Although such strategies probably serve scientific careers, we show that they slow scientific advance, especially in mature fields, where more risk and less redundant experimentation wouldmore » accelerate discovery of the network. Lastly, we also consider institutional arrangements that could help science pursue these more efficient strategies.« less

  1. MIT January Operational Internship Experience

    NASA Technical Reports Server (NTRS)

    Bosanac, Natasha; DeVivero, Charlie; James, Jillian; Perez-Martinez, Carla; Pino, Wendy; Wang, Andrew; Willett, Ezekiel; Williams, Kwami

    2010-01-01

    This viewgraph presentation describes the MIT January Operational Internship Experience (JOIE) program. The topics include: 1) Landing and Recovery; 2) Transportation; 3) Shuttle Processing; 4) Constellation Processing; 5) External Tank; 6) Launch Pad; 7) Ground Operations; 8) Hypergolic Propellants; 9) Environmental; 10) Logistics; 11) Six Sigma; 12) Systems Engineering; and 13) Human Factors.

  2. Pulsed power accelerator for material physics experiments

    NASA Astrophysics Data System (ADS)

    Reisman, D. B.; Stoltzfus, B. S.; Stygar, W. A.; Austin, K. N.; Waisman, E. M.; Hickman, R. J.; Davis, J.-P.; Haill, T. A.; Knudson, M. D.; Seagle, C. T.; Brown, J. L.; Goerz, D. A.; Spielman, R. B.; Goldlust, J. A.; Cravey, W. R.

    2015-09-01

    We have developed the design of Thor: a pulsed power accelerator that delivers a precisely shaped current pulse with a peak value as high as 7 MA to a strip-line load. The peak magnetic pressure achieved within a 1-cm-wide load is as high as 100 GPa. Thor is powered by as many as 288 decoupled and transit-time isolated bricks. Each brick consists of a single switch and two capacitors connected electrically in series. The bricks can be individually triggered to achieve a high degree of current pulse tailoring. Because the accelerator is impedance matched throughout, capacitor energy is delivered to the strip-line load with an efficiency as high as 50%. We used an iterative finite element method (FEM), circuit, and magnetohydrodynamic simulations to develop an optimized accelerator design. When powered by 96 bricks, Thor delivers as much as 4.1 MA to a load, and achieves peak magnetic pressures as high as 65 GPa. When powered by 288 bricks, Thor delivers as much as 6.9 MA to a load, and achieves magnetic pressures as high as 170 GPa. We have developed an algebraic calculational procedure that uses the single brick basis function to determine the brick-triggering sequence necessary to generate a highly tailored current pulse time history for shockless loading of samples. Thor will drive a wide variety of magnetically driven shockless ramp compression, shockless flyer plate, shock-ramp, equation of state, material strength, phase transition, and other advanced material physics experiments.

  3. Catalog of Apollo experiment operations

    NASA Technical Reports Server (NTRS)

    Sullivan, Thomas A.

    1994-01-01

    This catalog reviews Apollo mission reports, preliminary science reports, technical crew debriefings, lunar surface operations plans, and various relevant lunar experiment documents, collecting engineering- and operation-specific information by experiment. It is organized by discrete experimental and equipment items emplaced or operated on the lunar surface or at zero gravity during the Apollo missions. It also attempts to summarize some of the general problems encountered on the surface and provides guidelines for the design of future lunar surface experiments with an eye toward operations. Many of the problems dealt with on the lunar surface originated from just a few novel conditions that manifested themselves in various nasty ways. Low gravity caused cables to stick up and get caught on feet, and also made it easy for instruments to tip over. Dust was a problem and caused abrasion, visibility, and thermal control difficulties. Operating in a pressure suit limited a person's activity, especially in the hands. I hope to capture with this document some of the lessons learned from the Apollo era to make the jobs of future astronauts, principle investigators, engineers, and operators of lunar experiments more productive.

  4. Space Experiments with Particle Accelerators (SEPAC)

    NASA Technical Reports Server (NTRS)

    Taylor, William W. L.

    1994-01-01

    The scientific emphasis of this contract has been on the physics of beam ionosphere interactions, in particular, what are the plasma wave levels stimulated by the Space Experiments with Particle Accelerators (SEPAC) electron beam as it is ejected from the Electron Beam Accelerator (EBA) and passes into and through the ionosphere. There were two different phenomena expected. The first was generation of plasma waves by the interaction of the DC component of the beam with the plasma of the ionosphere, by wave particle interactions. The second was the generation of waves at the pulsing frequency of the beam (AC component). This is referred to as using the beam as a virtual antenna, because the beam of electrons is a coherent electrical current confined to move along the earth's magnetic field. As in a physical antenna, a conductor at a radio or TV station, the beam virtual antenna radiates electromagnetic waves at the frequency of the current variations. These two phenomena were investigated during the period of this contract.

  5. Disk Acceleration Experiment Utilizing Minimal Material (DAXUMM)

    NASA Astrophysics Data System (ADS)

    Biss, Matthew; Lorenz, Thomas; Sutherland, Gerrit

    2015-06-01

    A venture between the US Army Research Laboratory (ARL) and Lawrence Livermore National Laboratory (LLNL) is currently underway in an effort to characterize novel energetic material performance properties using a single, high-precision, gram-range charge. A nearly all-inclusive characterization experiment is proposed by combing LLNL's disk acceleration experiment (DAX) with the ARL explosive evaluation utilizing minimal material (AXEUMM) experiment. Spherical-cap charges fitted with a flat circular metal disk are centrally initiated using an exploding bridgewire detonator while photonic doppler velocimetry is used to probe the metal disk surface velocity and measure its temporal history. The metal disk's jump-off-velocity measurement is combined with conservation equations, material Hugoniots, and select empirical relationships to determine performance properties of the detonation wave (i.e., velocity, pressure, particle velocity, and density). Using the temporal velocity history with the numerical hydrocode CTH, a determination of the energetic material's equation of state and material expansion energy is possible. Initial experimental and computational results for the plastic-bonded energetic formulation PBXN-5 are presented.

  6. Comparison of integrated numerical experiments with accelerator and FEL experiments

    SciTech Connect

    Thode, L.E.; Carlsten, B.E.; Chan, K.C.D.; Cooper, R.K.; Elliott, J.C.; Gitomer, S.J.; Goldstein, J.C.; Jones, M.E.; McVey, B.D.; Schmitt, M.J.; Takeda, H.; Tokar, R.L.; Wang, T.S.; Young, L.M.

    1991-01-01

    Even at the conceptual level the strong coupling between the laser subsystem elements, such as the accelerator, wiggler, optics, and control, greatly complicates the understanding and design of an FEL. Given the requirements for a high-performance FEL, the coupling between the laser subsystems must be included in the design approach. To address the subsystem coupling the concept of an integrated numerical experiment (INEX) has been implemented. Unique features of the INEX approach are consistency and numerical equivalence of experimental diagnostic. The equivalent numerical diagnostics mitigates the major problem of misinterpretation that often occurs when theoretical and experimental data are compared. A complete INEX model has been applied to the 10{mu}m high-extraction-efficiency experiment at Los Alamos and the 0.6-{mu}m Burst Mode experiment at Boeing Aerospace. In addition, various subsets of the INEX model have been compared with a number of other experiments. Overall, the agreement between INEX and the experiments is very good. With the INEX approach, it now appears possible to design high-performance FELS for numerous applications. The first full-scale test of the INEX approach is the Los Alamos HIBAF experiment. The INEX concept, implementation, and validation with experiments are discussed. 28 refs., 13 figs., 1 tab.

  7. Comparing PRAs with operating experience

    SciTech Connect

    Picard, R.R.; Martz, H.F.

    1998-12-01

    Probabilistic Risk Assessment is widely used to estimate the frequencies of rare events, such as nuclear power plant accidents. An obvious question concerns the extent to which PRAs conform to operating experience--that is, do PRAs agree with reality? The authors discuss a formal methodology to address this issue and examine its performance using plant-specific data.

  8. Long-term operating experience for the ATLAS superconducting resonators

    SciTech Connect

    Pardo, R.; Zinkann, G.

    1999-12-21

    Portions of the ATLAS accelerator have been operating now for over 21 years. The facility has accumulated several million resonator-hours of operation at this point and has demonstrated the long-term reliability of RF superconductivity. The overall operating performance of the ATLAS facility has established a level of beam quality, flexibility, and reliability not previously achieved with heavy-ion accelerator facilities. The actual operating experience and maintenance history of ATLAS are presented for ATLAS resonators and associated electronics systems. Solutions to problems that appeared in early operation as well as current problems needing further development are discussed.

  9. Cryogenic supply for accelerators and experiments at FAIR

    SciTech Connect

    Kauschke, M.; Xiang, Y.; Schroeder, C. H.; Streicher, B.; Kollmus, H.

    2014-01-29

    In the coming years the new international accelerator facility FAIR (Facility for Antiproton and Ion Research), one of the largest research projects worldwide, will be built at GSI. In the final construction FAIR consists of synchrotrons and storage rings with up to 1,100 meters in circumference, two linear accelerators and about 3.5 kilometers beam transfer lines. The existing GSI accelerators serve as pre-accelerators. Partly the new machines will consist of superconducting magnets and therefore require a reliable supply with liquid helium. As the requirements for the magnets is depending on the machine and have a high variety, the cooling system is different for each machine; two phase cooling, forced flow cooling and bath cooling respectively. In addition the cold mass of the individual magnets varies between less than 1t up to 80t and some magnets will cause a dynamic heat load due to ramping that is higher than the static loads. The full cryogenic system will be operated above atmospheric pressure. The refrigeration and liquefaction power will be provided by two main cryogenic plants of 8 and 25 kW at 4K and two smaller plants next to the experiments.

  10. Inverse Cerenkov laser accelerator experiment annual report. 1990 Annual report

    SciTech Connect

    Not Available

    1991-03-29

    During the past year further progress was made on preparations for the Spectra Technology, Inc. (STI) inverse Cerenkov acceleration (ICA) experiment to be performed on the Accelerator Test Facility (ATF) at Brookhaven National Laboratory. Major progress was made in the design and fabrication of the experimental apparatus. This includes the gas cell, where the ICA process occurs, and the optical system that converts the CO{sub 2} laser beam into a radially polarized beam. In terms of progress on theoretical work, the authors finished optimizing the ATF ICA design parameters using their Monte Carlo computer simulation. The optimized design predicts for the ATF conditions that over 50% energy gain should be observed. They published a paper on an improved method of performing ICA by operating near the resonance of a gas. They also began analysis of a method of accelerating particles in a vacuum using a radially polarized beam and axicon focusing. Although this new method can no longer be considered ICA, it has the potential of high acceleration gradients without the drawbacks of gas scattering and gas breakdown. Three papers were published and two conference papers were presented during 1990.

  11. Argonne plasma wake-field acceleration experiments

    SciTech Connect

    Rosenzweig, J.B.; Cole, B.; Gai, W.; Konecny, R.; Norem, J.; Schoessow, P.; Simpson, J.

    1989-03-14

    Four years after the initial proposal of the Plasma Wake-field Accelerator (PWFA), it continues to be the object of much investigation, due to the promise of the ultra-high accelerating gradients that can exist in relativistic plasma waves driven in the wake of charged particle beams. These wake-fields are of interest both in the laboratory, for acceleration and focusing of electrons and positrons in future linear colliders, and in nature as a possible cosmic ray acceleration mechanism. The purpose of the present work is to review the recent experimental advances made in PWFA research at Argonne National Laboratory. Some of the topics discussed are: the Argonne Advanced Accelerator Test Facility; linear plasma wake-field theory; measurement of linear plasma wake-fields; review of nonlinear plasma wave theory; and experimental measurement of nonlinear plasma wake-fields. 25 refs., 11 figs.

  12. Space Experiments with Particle Accelerators (SEPAC), status review, 23 September 1980

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The development responsibilities of SEPAC include: accelerator systems, diagnostic systems, power systems, dedicated experiment processor, interface unit, control panel, and all flight software. The operations of SEPAC, including automated experiments under DEP command control and SEPAC manual operations, are outlined. A diagram of the system configuration is presented.

  13. An inverse free electron laser accelerator: Experiment and theoretical interpretation

    SciTech Connect

    Fang, Jyan-Min

    1997-06-01

    Experimental and numerical studies of the Inverse Free Electron Laser using a GW-level 10.6 {mu}m CO{sub 2} laser have been carried out at Brookhaven`s Accelerator Test Facility. An energy gain of 2.5 % ({Delta}E/E) on a 40 MeV electron beam has been observed E which compares well with theory. The effects on IFEL acceleration with respect to the variation of the laser electric field, the input electron beam energy, and the wiggler magnetic field strength were studied, and show the importance of matching the resonance condition in the IFEL. The numerical simulations were performed under various conditions and the importance of the electron bunching in the IFEL is shown. The numerical interpretation of our IFEL experimental results was examined. Although good numerical agreement with the experimental results was obtained, there is a discrepancy between the level of the laser power measured in the experiment and used in the simulation, possibly due to the non-Gaussian profile of the input high power laser beam. The electron energy distribution was studied numerically and a smoothing of the energy spectrum by the space charge effect at the location of the spectrometer was found, compared with the spectrum at the exit of the wiggler. The electron bunching by the IFEL and the possibility of using the IFEL as an electron prebuncher for another laser-driven accelerator were studied numerically. We found that bunching of the electrons at 1 meter downstream from the wiggler can be achieved using the existing facility. The simulation shows that there is a fundamental difference between the operating conditions for using the IFEL as a high gradient accelerator, and as a prebuncher for another accelerator.

  14. The SILEX experiment system operations

    NASA Astrophysics Data System (ADS)

    Demelenne, B.

    1994-11-01

    The European Space Agency is going to conduct an inter orbit link experiment which will connect a low Earth orbiting satellite and a Geostationary satellite via optical terminals. This experiment has been called SILEX (Semiconductor Inter satellite Link EXperiment). Two payloads will be built. One called PASTEL (PASsager de TELecommunication) will be embarked on the French Earth observation satellite SPOT4. The future European experimental data relay satellite ARTEMIS (Advanced Relay and TEchnology MISsion) will carry the OPALE terminal (Optical PAyload Experiment). The principal characteristic of the mission is a 50 Megabits flow of data transmitted via the optical satellite link. The relay satellite will route the data via its feeder link thus permitting a real time reception in the European region of images taken by the observation satellite. The PASTEL terminal has been designed to cover up to 9 communication sessions per day with an average of 5. The number of daily contact opportunities with the low earth orbiting satellite will be increased and the duration will be much longer than the traditional passes over a ground station. The terminals have an autonomy of 24 hours with respect to ground control. Each terminal will contain its own orbit model and that of its counter terminal for orbit prediction and for precise computation of pointing direction. Due to the very narrow field of view of the communication laser beam, the orbit propagation calculation needs to be done with a very high accuracy. The European Space Agency is responsible for the operation of both terminals. A PASTEL Mission Control System (PMCS) is being developed to control the PASTEL terminal on board SPOT4. The PMCS will interface with the SPOT4 Control Centre for the execution of the PASTEL operations. The PMCS will also interface with the ARTEMIS Mission Control System for the planning and the coordination of the operation. It is the first time that laser technology will be used to support

  15. Design and initial operation of LELIA induction accelerator

    NASA Astrophysics Data System (ADS)

    Bardy, J.; Eyharts, P.; Anthouard, P.; Eyl, P.; Labrouche, J.; Launspach, J.; Le Taillandier, P.; de Mascureau, J.; Thevenot, M.

    1991-07-01

    The objective of the LELIA program is to produce a high-brightness and high-average-power electron beam for FEL applications. Therefore a linear induction accelerator is under development at CESTA. As a first step, a prototype induction cell has been constructed and tested in order to check its mechanical design feasibility and experimental electrical response, gap geometry and vacuum technology. Moreover, by the end of 1990, an injector will operate with the following parameters: 1.5 MeV beam energy; 1/5 kA beam current; 60 ns flat-top pulse with a few Hz repetition rate capability. An osmium dispenser cathode will produce the high-current-density electron beam. Numerical simulations have also been processed in order to study the beam cavity coupling, minimize the beam breakup (BBU) instability, and optimize the injector electrode configuration. To drive the induction cells a high-power pulse generator has been developed. It consists of two parts: (i) a command resonant charging system (CRCS), (ii) a pulse-forming and magnetic compression device (MAG). Initially the CRCS was tested with a resistive load and the MAG with a spark-gap driver. These preliminary experiments have been successful and the high-voltage flat top has been further improved by charging the MAG-forming line in the middle. A new generator including a cooling system, designed for high-repetition operation, is now under construction.

  16. Stack Monitor Operating Experience Review

    SciTech Connect

    L. C. Cadwallader; S. A. Bruyere

    2009-05-01

    Stack monitors are used to sense radioactive particulates and gases in effluent air being vented from rooms of nuclear facilities. These monitors record the levels and types of effluents to the environment. This paper presents the results of a stack monitor operating experience review of the U.S. Department of Energy (DOE) Occurrence Reporting and Processing System (ORPS) database records from the past 18 years. Regulations regarding these monitors are briefly described. Operating experiences reported by the U.S. DOE and in engineering literature sources were reviewed to determine the strengths and weaknesses of these monitors. Electrical faults, radiation instrumentation faults, and human errors are the three leading causes of failures. A representative “all modes” failure rate is 1E-04/hr. Repair time estimates vary from an average repair time of 17.5 hours (with spare parts on hand) to 160 hours (without spare parts on hand). These data should support the use of stack monitors in any nuclear facility, including the National Ignition Facility and the international ITER project.

  17. Operational and design aspects of accelerators for medical applications

    NASA Astrophysics Data System (ADS)

    Schippers, Jacobus Maarten; Seidel, Mike

    2015-03-01

    Originally, the typical particle accelerators as well as their associated beam transport equipment were designed for particle and nuclear physics research and applications in isotope production. In the past few decades, such accelerators and related equipment have also been applied for medical use. This can be in the original physics laboratory environment, but for the past 20 years also in hospital-based or purely clinical environments for particle therapy. The most important specific requirements of accelerators for radiation therapy with protons or ions will be discussed. The focus will be on accelerator design, operational, and formal aspects. We will discuss the special requirements to reach a high reliability for patient treatments as well as an accurate delivery of the dose at the correct position in the patient using modern techniques like pencil beam scanning. It will be shown that the technical requirements, safety aspects, and required reliability of the accelerated beam differ substantially from those in a nuclear physics laboratory. It will be shown that this difference has significant implications on the safety and interlock systems. The operation of such a medical facility should be possible by nonaccelerator specialists at different operating sites (treatment rooms). The organization and role of the control and interlock systems can be considered as being the most crucially important issue, and therefore a special, dedicated design is absolutely necessary in a facility providing particle therapy.

  18. Operational experience with CW high gradient and high QL cryomodules

    SciTech Connect

    Hovater, J. Curt; Allison, Trent L.; Bachimanchi, Ramakrishna; Daly, Edward F.; Drury, Michael A.; Lahti, George E.; Mounts, Clyde I.; Nelson, Richard M.; Plawski, Tomasz E.

    2014-12-01

    The Continuous Electron Beam Accelerator Facility (CEBAF) energy upgrade from 6 GeV to 12 GeV includes the installation of ten new 100 MV cryomodules (80 cavities). The superconducting RF cavities are designed to operate CW at an accelerating gradient of 19.3 MV/m with a QL of 3×107. The RF system employs single cavity control using new digital LLRF controls and 13 kW klystrons. Recently, all of the new cryomodules and associated RF hardware and software have been commissioned and operated in the CEBAF accelerator. Electrons at linac currents up to 10 ?A have been successfully accelerated and used for nuclear physics experiments. This paper reports on the commissioning and operation of the cryomodules and RF system.

  19. Accelerated Aging Experiments for Capacitor Health Monitoring and Prognostics

    NASA Technical Reports Server (NTRS)

    Kulkarni, Chetan S.; Celaya, Jose Ramon; Biswas, Gautam; Goebel, Kai

    2012-01-01

    This paper discusses experimental setups for health monitoring and prognostics of electrolytic capacitors under nominal operation and accelerated aging conditions. Electrolytic capacitors have higher failure rates than other components in electronic systems like power drives, power converters etc. Our current work focuses on developing first-principles-based degradation models for electrolytic capacitors under varying electrical and thermal stress conditions. Prognostics and health management for electronic systems aims to predict the onset of faults, study causes for system degradation, and accurately compute remaining useful life. Accelerated life test methods are often used in prognostics research as a way to model multiple causes and assess the effects of the degradation process through time. It also allows for the identification and study of different failure mechanisms and their relationships under different operating conditions. Experiments are designed for aging of the capacitors such that the degradation pattern induced by the aging can be monitored and analyzed. Experimental setups and data collection methods are presented to demonstrate this approach.

  20. Operating experiences of retardant bombers during firefighting operations

    NASA Technical Reports Server (NTRS)

    Jewel, J. W., Jr.; Morris, G. J.; Avery, D. E.

    1974-01-01

    Data are presented on operational practices and maneuver accelerations experienced by two Douglas DC-6B airplanes converted to retardant bombers and used in firefighting operations. The data cover two fire seasons in the mountainous regions of the northwestern United States.

  1. The operation of the LHC accelerator complex (1/2)

    ScienceCinema

    None

    2011-10-06

    These lectures will give an overview of what happens when the LHC is in running mode. They are aimed at students working on the LHC experiments, but all those who are curious about what happens behind the scenes of the LHC are welcomed. You will learn all you always wanted to know about the LHC, and never had the courage to ask! The only pre-requisite is a basic, college-level, knowledge of EM and of the principles that allow to steer charged beams. Topics covered will include, among others: - the description of the injector chain, from the generation of the protons, to the delivery of bunches to the LHC. - the discussion of the steps required to accelerate the beams in the LHC, to bring them into collision, and to control the luminosity at the interaction points. - the description of the monitoring tools available to the LHC operators, and an explanation of the various plots and panels that can be found on the LHC web pages. o Lecture 1: Wednesday April 7, 10-11am o Lecture 2: Friday April 9, 10-11am The lectures will be webcast, recorded and archived. Coffee will be served before the lectures, starting at 9:45

  2. The operation of the LHC accelerator complex (2/2)

    ScienceCinema

    None

    2011-10-06

    These lectures will give an overview of what happens when the LHC is in running mode. They are aimed at students working on the LHC experiments, but all those who are curious about what happens behind the scenes of the LHC are welcomed. You will learn all you always wanted to know about the LHC, and never had the courage to ask! The only pre-requisite is a basic, college-level, knowledge of EM and of the principles that allow to steer charged beams. Topics covered will include, among others: - the description of the injector chain, from the generation of the protons, to the delivery of bunches to the LHC. - the discussion of the steps required to accelerate the beams in the LHC, to bring them into collision, and to control the luminosity at the interaction points. - the description of the monitoring tools available to the LHC operators, and an explanation of the various plots and panels that can be found on the LHC web pages. o Lecture 1: Wednesday April 7, 10-11am o Lecture 2: Friday April 9, 10-11am The lectures will be webcast, recorded and archived. Coffee will be served before the lectures, starting at 9:45

  3. The operation of the LHC accelerator complex (1/2)

    SciTech Connect

    2010-04-07

    These lectures will give an overview of what happens when the LHC is in running mode. They are aimed at students working on the LHC experiments, but all those who are curious about what happens behind the scenes of the LHC are welcomed. You will learn all you always wanted to know about the LHC, and never had the courage to ask! The only pre-requisite is a basic, college-level, knowledge of EM and of the principles that allow to steer charged beams. Topics covered will include, among others: - the description of the injector chain, from the generation of the protons, to the delivery of bunches to the LHC. - the discussion of the steps required to accelerate the beams in the LHC, to bring them into collision, and to control the luminosity at the interaction points. - the description of the monitoring tools available to the LHC operators, and an explanation of the various plots and panels that can be found on the LHC web pages. o Lecture 1: Wednesday April 7, 10-11am o Lecture 2: Friday April 9, 10-11am The lectures will be webcast, recorded and archived. Coffee will be served before the lectures, starting at 9:45

  4. The operation of the LHC accelerator complex (2/2)

    SciTech Connect

    2010-04-09

    These lectures will give an overview of what happens when the LHC is in running mode. They are aimed at students working on the LHC experiments, but all those who are curious about what happens behind the scenes of the LHC are welcomed. You will learn all you always wanted to know about the LHC, and never had the courage to ask! The only pre-requisite is a basic, college-level, knowledge of EM and of the principles that allow to steer charged beams. Topics covered will include, among others: - the description of the injector chain, from the generation of the protons, to the delivery of bunches to the LHC. - the discussion of the steps required to accelerate the beams in the LHC, to bring them into collision, and to control the luminosity at the interaction points. - the description of the monitoring tools available to the LHC operators, and an explanation of the various plots and panels that can be found on the LHC web pages. o Lecture 1: Wednesday April 7, 10-11am o Lecture 2: Friday April 9, 10-11am The lectures will be webcast, recorded and archived. Coffee will be served before the lectures, starting at 9:45

  5. Fire protection system operating experience review for fusion applications

    SciTech Connect

    Cadwallader, L.C.

    1995-12-01

    This report presents a review of fire protection system operating experiences from particle accelerator, fusion experiment, and other applications. Safety relevant operating experiences and accident information are discussed. Quantitative order-of-magnitude estimates of fire protection system component failure rates and fire accident initiating event frequencies are presented for use in risk assessment, reliability, and availability studies. Safety concerns with these systems are discussed, including spurious operation. This information should be useful to fusion system designers and safety analysts, such as the team working on the Engineering Design Activities for the International Thermonuclear Experimental Reactor.

  6. Space Experiments with Particle Accelerators: SEPAC - SEPAC program for First Spacelab Mission

    NASA Astrophysics Data System (ADS)

    Obayashi, T.

    The Space Shuttle/Spacelab Mission Space Experiment with Particle Accelerators (SEPAC) will carry out interactive experiments on, and in, the earth ionosphere and magnetosphere, and comprises an electron beam accelerator, MPD arcjet, and associated diagnostic equipment. The mission Payload Specialist will be responsible for (1) manual control of scientific instruments, (2) monitoring of experiment displays, (3) restructuring of experiment sequence by means of display system keyboard, (4) safety and emergency operations, and (5) voice communications. Attention is given to the configurational and sequential organization of the SEPAC experiments.

  7. Quasi-steady accelerator operation on the ZAP flow Z-pinch

    NASA Astrophysics Data System (ADS)

    Hughes, M. C.; Shumlak, U.; Golingo, R. P.; Nelson, B. A.; Ross, M. P.

    2014-12-01

    The ZaP Flow Z-Pinch Experiment utilizes sheared flows to stabilize an otherwise unstable equilibrium. The sheared flows are maintained by streaming high velocity plasma parallel to the pinch. Previous operations of the machine show depletion of the accelerator's neutral gas supply late in the pulse leading to pinch instability. The current distribution in the accelerator exhibits characteristic modes during this operation, which is corroborated by interferometric signals. The decrease in density precipitates a loss of plasma quiescence in the pinch, which occurs on a timescale related to the flow velocity from the plasma source. To abate the depletion, the geometry of the accelerator is altered to increase the neutral gas supply. The design creates a standing deflagration front in the accelerator that persists for the pulse duration. The new operating mode is characterized by the same diagnostics as the previous mode. The lessons learned in the accelerator operations have been applied to the design of a new experiment, ZaP-HD. This work was supported by grants from the Department of Energy and the National Nuclear Security Administration.

  8. TeV/m Nano-Accelerator: Current Status of CNT-Channeling Acceleration Experiment

    SciTech Connect

    Shin, Young Min; Lumpkin, Alex H.; Thangaraj, Jayakar Charles; Thurman-Keup, Randy Michael; Shiltsev, Vladimir D.

    2014-09-17

    Crystal channeling technology has offered various opportunities in the accelerator community with a viability of ultrahigh gradient (TV/m) acceleration for future HEP collider. The major challenge of channeling acceleration is that ultimate acceleration gradients might require a high power driver in the hard x-ray regime (~ 40 keV). This x-ray energy exceeds those for x-rays as of today, although x-ray lasers can efficiently excite solid plasma and accelerate particles inside a crystal channel. Moreover, only disposable crystal accelerators are possible at such high externally excited fields which would exceed the ionization thresholds destroying the atomic structure, so acceleration will take place only in a short time before full dissociation of the lattice. Carbon-based nanostructures have great potential with a wide range of flexibility and superior physical strength, which can be applied to channeling acceleration. This paper presents a beam- driven channeling acceleration concept with CNTs and discusses feasible experiments with the Advanced Superconducting Test Accelerator (ASTA) in Fermilab.

  9. The electron accelerator for the AWAKE experiment at CERN

    NASA Astrophysics Data System (ADS)

    Pepitone, K.; Doebert, S.; Burt, G.; Chevallay, E.; Chritin, N.; Delory, C.; Fedosseev, V.; Hessler, Ch.; McMonagle, G.; Mete, O.; Verzilov, V.; Apsimon, R.

    2016-09-01

    The AWAKE collaboration prepares a proton driven plasma wakefield acceleration experiment using the SPS beam at CERN. A long proton bunch extracted from the SPS interacts with a high power laser and a 10 m long rubidium vapour plasma cell to create strong wakefields allowing sustained electron acceleration. The electron bunch to probe these wakefields is supplied by a 20 MeV electron accelerator. The electron accelerator consists of an RF-gun and a short booster structure. This electron source should provide beams with intensities between 0.1 and 1 nC, bunch lengths between 0.3 and 3 ps and an emittance of the order of 2 mm mrad. The wide range of parameters should cope with the uncertainties and future prospects of the planned experiments. The layout of the electron accelerator, its instrumentation and beam dynamics simulations are presented.

  10. Operations and maintenance manual for the linear accelerator (sled)

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The Linear Accelerator, a sliding chair which is pulled along a stationary platform in a horizontal axis is described. The driving force is a motor controlled by a velocity loop amplifier, and the mechanical link to the chair is a steel cable. The chair is moved in forward and reverse directions as indicated by the direction of motor rotation. The system operation is described with emphasis on the electronic control and monitoring functions. Line-by-line schematics and wire lists are included.

  11. Numerical and Experimental Investigation of the Effects of Acceleration Disturbances on Microgravity Experiments

    NASA Technical Reports Server (NTRS)

    Ramachandran, Narayanan

    2000-01-01

    Normal vibrational modes on large spacecraft are excited by crew activity, operating machinery, and other mechanical disturbances. Periodic engine burns for maintaining vehicle attitude and random impulse type disturbances also contribute to the acceleration environment of a Spacecraft. Accelerations from these vibrations (often referred to as g-jitter) are several orders of magnitude larger than the residual accelerations from atmospheric drag and gravity gradient effects. Naturally, the effects of such accelerations have been a concern to prospective experimenters wishing to take advantage of the microgravity environment offered by spacecraft operating in low Earth orbit and the topic has been studied extensively, both numerically and analytically. However, these studies have not produced a general theory that predicts the effects of multi-spectral periodic accelerations on a general class of experiments nor have they produced scaling laws that a prospective experimenter could use to assess how his/her experiment might be affected by this acceleration environment. Furthermore, there are no actual flight experimental data that correlates heat or mass transport with measurements of the periodic acceleration environment. The present investigation approaches this problem with carefully conducted terrestrial experiments and rigorous numerical modeling thereby providing comparative theoretical and experimental data. The modeling, it is hoped will provide a predictive tool that can be used for assessing experiment response to Spacecraft vibrations.

  12. Operational Amplifier Experiments for the Chemistry Laboratory.

    ERIC Educational Resources Information Center

    Braun, Robert D.

    1996-01-01

    Provides details of experiments that deal with the use of operational amplifiers and are part of a course in instrumental analysis. These experiments are performed after the completion of a set of electricity and electronics experiments. (DDR)

  13. Jefferson Lab Accelerator Operations Training and Development Program

    SciTech Connect

    Michael A. Epps

    2008-01-23

    The mission of the Jefferson Lab Operations Group is to provide safe and efficient delivery of high quality electron beam for Jefferson Laboratory's nuclear and accelerator physics programs. The Operations staff must be able to setup, transport, maintain, and troubleshoot beam to all three experimental halls in a safe, efficient, and expeditious manner. Due to the nature of shift work, high employee turnover is always as issue. This creates a unique situation where highly trained staff members must quickly be produced and maintained in order to meet the needs of the Laboratory. Some methods used to address this problem will be presented here.

  14. Operational Radiation Protection in High-Energy Physics Accelerators

    SciTech Connect

    Rokni, S.H.; Fasso, A.; Liu, J.C.; /SLAC

    2012-04-03

    An overview of operational radiation protection (RP) policies and practices at high-energy electron and proton accelerators used for physics research is presented. The different radiation fields and hazards typical of these facilities are described, as well as access control and radiation control systems. The implementation of an operational RP programme is illustrated, covering area and personnel classification and monitoring, radiation surveys, radiological environmental protection, management of induced radioactivity, radiological work planning and control, management of radioactive materials and wastes, facility dismantling and decommissioning, instrumentation and training.

  15. Laser Wakefield Acceleration Experiments Using HERCULES Laser

    SciTech Connect

    Matsuoka, T.; McGuffey, C.; Dollar, F.; Bulanov, S. S.; Chvykov, V.; Kalintchenko, G.; Rousseau, P.; Yanovsky, V.; Maksimchuk, A.; Krushelnick, K.; Horovitz, Y.

    2009-07-25

    Laser wakefield acceleration (LWFA) in a supersonic gas-jet using a self-guided laser pulse was studied by changing laser power and plasma electron density. The recently upgraded HERCULES laser facility equipped with wavefront correction enables a peak intensity of 6.1x10{sup 19} W/cm{sup 2} at laser power of 80 TW to be delivered to the gas-jet using F/10 focusing optics. We found that electron beam charge was increased significantly with an increase of laser power from 30 TW to 80 TW and showed density threshold behavior at a fixed laser power. We also studied the influence of laser focusing conditions by changing the f-number of the optics to F/15 and found an increase in density threshold for electron production compared to the F/10 configuration. The analysis of different phenomena such as betatron motion of electrons, side scattering of the laser pulse for different focusing conditions, the influence of plasma density down ramp on LWFA are shown.

  16. Cryogenic system operating experience review for fusion applications

    SciTech Connect

    Cadwallader, L.C.

    1992-01-01

    This report presents a review of cryogenic system operating experiences, from particle accelerator, fusion experiment, space research, and other applications. Safety relevant operating experiences and accident information are discussed. Quantitative order-of-magnitude estimates of cryogenic component failure rates and accident initiating event frequencies are presented for use in risk assessment, reliability, and availability studies. Safety concerns with cryogenic systems are discussed, including ozone formation, effects of spills, and modeling spill behavior. This information should be useful to fusion system designers and safety analysts, such as the team working on the International Thermonuclear Experimental Reactor design.

  17. 14 CFR 135.244 - Operating experience.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Operating experience. 135.244 Section 135.244 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS AND OPERATORS FOR COMPENSATION OR HIRE: CERTIFICATION AND OPERATIONS OPERATING REQUIREMENTS: COMMUTER AND ON DEMAND OPERATIONS AND...

  18. Operational experience with light ions at BNL

    SciTech Connect

    Reece, R.K.; Ahrens, L.A.; Barton, D.S.; Beavis, D.; Benjamin, J.; Foelsche, H.; Gardner, C.; Gill, E.; Raka, E.; Sidhu, S.

    1987-03-01

    A new transfer line has joined the Tandem Van de Graaff facility and the AGS at Brookhaven National Laboratory, permitting the acceleration of light ions (up to sulfur) to 14.5 GeV/nucleon. The Tandem, operating with a pulsed ion source, supplies a fully stripped ion beam at about 7 MeV/nucleon to the AGS. A new low frequency rf system accelerates the beam in the AGS to about 200 MeV/nucleon. The previously existing rf system completes the cycle. High energy ion beams are delivered using standard resonant extraction to four experimental beam lines. Details of techniques and preliminary performance and operational characteristics are discussed.

  19. Quasi-steady accelerator operation on the ZAP flow Z-pinch

    SciTech Connect

    Hughes, M. C. Shumlak, U. Golingo, R. P. Nelson, B. A. Ross, M. P.

    2014-12-15

    The ZaP Flow Z-Pinch Experiment utilizes sheared flows to stabilize an otherwise unstable equilibrium. The sheared flows are maintained by streaming high velocity plasma parallel to the pinch. Previous operations of the machine show depletion of the accelerator’s neutral gas supply late in the pulse leading to pinch instability. The current distribution in the accelerator exhibits characteristic modes during this operation, which is corroborated by interferometric signals. The decrease in density precipitates a loss of plasma quiescence in the pinch, which occurs on a timescale related to the flow velocity from the plasma source. To abate the depletion, the geometry of the accelerator is altered to increase the neutral gas supply. The design creates a standing deflagration front in the accelerator that persists for the pulse duration. The new operating mode is characterized by the same diagnostics as the previous mode. The lessons learned in the accelerator operations have been applied to the design of a new experiment, ZaP-HD. This work was supported by grants from the Department of Energy and the National Nuclear Security Administration.

  20. Ion accelerator systems for high power 30-cm thruster operation

    NASA Technical Reports Server (NTRS)

    Aston, G.

    1982-01-01

    An investigation of two- and three-grid accelerator systems for high power ion thruster operation has been performed. Two-grid translation tests show that overcompensation of the 30-cm thruster SHAG (Small Hole Accelerator Grid) leads to a premature impingement limit. By better matching the SHAG grid set spacing to the 30-cm thruster radial plasma density variation and by incorporating grid compensation only sufficient to maintain grid hole axial alignment, it is shown that beam current gains as large as 50% can be realized. Three-grid translation tests performed with a simulated 30-cm thruster discharge chamber show that substantial beamlet steering can be reliably affected by decelerator grid translation only, at net-to-total voltage ratios as low as 0.05.

  1. Operation and reactivity measurements of an accelerator driven subcritical TRIGA reactor

    NASA Astrophysics Data System (ADS)

    O'Kelly, David Sean

    Experiments were performed at the Nuclear Engineering Teaching Laboratory (NETL) in 2005 and 2006 in which a 20 MeV linear electron accelerator operating as a photoneutron source was coupled to the TRIGA (Training, Research, Isotope production, General Atomics) Mark II research reactor at the University of Texas at Austin (UT) to simulate the operation and characteristics of a full-scale accelerator driven subcritical system (ADSS). The experimental program provided a relatively low-cost substitute for the higher power and complexity of internationally proposed systems utilizing proton accelerators and spallation neutron sources for an advanced ADSS that may be used for the burning of high-level radioactive waste. Various instrumentation methods that permitted ADSS neutron flux monitoring in high gamma radiation fields were successfully explored and the data was used to evaluate the Stochastic Pulsed Feynman method for reactivity monitoring.

  2. Facilitating an accelerated experience-based co-design project.

    PubMed

    Tollyfield, Ruth

    This article describes an accelerated experience-based co-design (AEBCD) quality improvement project that was undertaken in an adult critical care setting and the facilitation of that process. In doing so the aim is to encourage other clinical settings to engage with their patients, carers and staff alike and undertake their own quality improvement project. Patient, carer and staff experience and its place in the quality sphere is outlined and the importance of capturing patient, carer and staff feedback established. Experience-based co-design (EBCD) is described along with the recently tested accelerated version of the process. An overview of the project and outline of the organisational tasks and activities undertaken by the facilitator are given. The facilitation of the process and key outcomes are discussed and reflected on. Recommendations for future undertakings of the accelerated process are given and conclusions drawn. PMID:24526020

  3. Ultrashort laser pulse driven inverse free electron laser accelerator experiment

    NASA Astrophysics Data System (ADS)

    Moody, J. T.; Anderson, S. G.; Anderson, G.; Betts, S.; Fisher, S.; Tremaine, A.; Musumeci, P.

    2016-02-01

    In this paper we discuss the ultrashort pulse high gradient inverse free electron laser accelerator experiment carried out at the Lawrence Livermore National Laboratory which demonstrated gradients exceeding 200 MV /m using a 4 TW 100 fs long 800 nm Ti :Sa laser pulse. Due to the short laser and electron pulse lengths, synchronization was determined to be one of the main challenges in this experiment. This made necessary the implementation of a single-shot, nondestructive, electro-optic sampling based diagnostics to enable time-stamping of each laser accelerator shot with <100 fs accuracy. The results of this experiment are expected to pave the way towards the development of future GeV-class IFEL accelerators.

  4. Operational experience with superconducting synchrotron magnets

    SciTech Connect

    Martin, P.S.

    1987-03-01

    The operational experience with the Fermilab Tevatron is presented, with emphasis on reliability and failure modes. Comprisons are made between the operating efficiencies for the superconducting machine and for he conventional Main Ring.

  5. Choosing experiments to accelerate collective discovery

    PubMed Central

    Rzhetsky, Andrey; Foster, Jacob G.; Foster, Ian T.

    2015-01-01

    A scientist’s choice of research problem affects his or her personal career trajectory. Scientists’ combined choices affect the direction and efficiency of scientific discovery as a whole. In this paper, we infer preferences that shape problem selection from patterns of published findings and then quantify their efficiency. We represent research problems as links between scientific entities in a knowledge network. We then build a generative model of discovery informed by qualitative research on scientific problem selection. We map salient features from this literature to key network properties: an entity’s importance corresponds to its degree centrality, and a problem’s difficulty corresponds to the network distance it spans. Drawing on millions of papers and patents published over 30 years, we use this model to infer the typical research strategy used to explore chemical relationships in biomedicine. This strategy generates conservative research choices focused on building up knowledge around important molecules. These choices become more conservative over time. The observed strategy is efficient for initial exploration of the network and supports scientific careers that require steady output, but is inefficient for science as a whole. Through supercomputer experiments on a sample of the network, we study thousands of alternatives and identify strategies much more efficient at exploring mature knowledge networks. We find that increased risk-taking and the publication of experimental failures would substantially improve the speed of discovery. We consider institutional shifts in grant making, evaluation, and publication that would help realize these efficiencies. PMID:26554009

  6. Ion accelerator systems for high power 30 cm thruster operation

    NASA Technical Reports Server (NTRS)

    Aston, G.

    1982-01-01

    Two and three-grid accelerator systems for high power ion thruster operation were investigated. Two-grid translation tests show that over compensation of the 30 cm thruster SHAG grid set spacing the 30 cm thruster radial plasma density variation and by incorporating grid compensation only sufficient to maintain grid hole axial alignment, it is shown that beam current gains as large as 50% can be realized. Three-grid translation tests performed with a simulated 30 cm thruster discharge chamber show that substantial beamlet steering can be reliably affected by decelerator grid translation only, at net-to-total voltage ratios as low as 0.05.

  7. ACCELERATOR PHYSICS MODEL OF EXPECTED BEAM LOSS ALONG THE SNS ACCELERATOR FACILITY DURING NORMAL OPERATION.

    SciTech Connect

    CATALAN - LASHERAS,N.; COUSINEAU,S.; GALAMBOS,J.; HOLTKAMP,N.; RAPARIA,D.; SHAFER,R.; STAPLES,J.; STOVALL,J.; TANKE,E.; WANGLER,T.; WEI,J.

    2002-06-03

    The most demanding requirement in the design of the SNS accelerator chain is to keep the accelerator complex under hands-on maintenance. This requirement implies a hard limit for residual radiation below 100 mrem/hr at one feet from the vacuum pipe and four hours after shutdown for hundred days of normal operation. It has been shown by measurements as well as simulation [l] that this limit corresponds to 1-2 Watts/meter average beam losses. This loss level is achievable all around the machine except in specific areas where remote handling will be necessary. These areas have been identified and correspond to collimation sections and dumps where a larger amount of controlled beam loss is foreseen. Even if the average level of loss is kept under 1 W/m, there are circumstances under which transient losses occur in the machine. The prompt radiation or potential damage in the accelerator components can not be deduced from an average beam loss of 1 W/m. At the same time, controlled loss areas require a dedicated study to clarify the magnitude and distribution of the beam loss. From the front end to the target, we have estimated the most probable locations for transient losses and given an estimate of their magnitude and frequency. This information is essential to calculate the necessary shielding or determine the safety procedures during machine operation. Losses in controlled areas, and the cleaning systems are the subject of Section 2. The inefficiency of each system will be taken into account for the discussion on Section 3 where n controlled loss is estimated. Section 4 summarizes our findings and presents a global view of the losses along the accelerator chain.

  8. The Drop Tower Bremen -Experiment Operation

    NASA Astrophysics Data System (ADS)

    Könemann, Thorben; von Kampen, Peter; Rath, Hans J.

    microgravity project at the Drop Tower Bremen, interesting experimentalists should keep in mind generally reducing dimensions and masses of their common laboratory setups to meet the capsule constraints: overall payload height 980mm/1730mm (short/long drop capsule) and 950mm (catapult capsule); area of each capsule platform 0,359sqm; maximum payload mass 274kg/234kg (short/long drop capsule) and 163,8kg (catapult capsule). The base equipments of each capsule are the Capsule Control System (CCS) to remote control the experiment and the rechargeable battery pack (24V/40A) for the experiment operation. Moreover, the exper-iment components must be able to withstand maximum decelerations of 50g while the short capsule impact of about 200ms, and maximum accelerations of 30g while catapult launch with a duration of about 300ms. In our second talk concerning ZARM`s drop tower facility we will go on with detailed infor-mations about the technical base setups of the drop and the catapult capsule structure to completely handle a freely falling experiment. Furthermore, we will summarize interesting current drop tower projects as an outlook to present you the range of opportunities at the ground-based short-term microgravity laboratory of ZARM.

  9. Space experiments with particle accelerators (SEPAC): Description of instrumentation

    NASA Technical Reports Server (NTRS)

    Taylor, W. W. L.; Roberts, W. T.; Reasoner, D. L.; Chappell, C. R.; Baker, B. B.; Burch, J. L.; Gibson, W. C.; Black, R. K.; Tomlinson, W. M.; Bounds, J. R.

    1987-01-01

    SEPAC (Space Experiments with Particle Accelerators) flew on Spacelab 1 (SL 1) in November and December 1983. SEPAC is a joint U.S.-Japan investigation of the interaction of electron, plasma, and neutral beams with the ionosphere, atmosphere and magnetosphere. It is scheduled to fly again on Atlas 1 in August 1990. On SL 1, SEPAC used an electron accelerator, a plasma accelerator, and neutral gas source as active elements and an array of diagnostics to investigate the interactions. For Atlas 1, the plasma accelerator will be replaced by a plasma contactor and charge collection devices to improve vehicle charging meutralization. This paper describes the SEPAC instrumentation in detail for the SL 1 and Atlas 1 flights and includes a bibliography of SEPAC papers.

  10. Recent operational experiments at the LANSCE facility

    SciTech Connect

    Rybarcyk, Lawrence J

    2010-09-15

    The Los Alamos Neutron Science Center (LANSCE) consists of a pulsed 800-MeV room-temperature linear accelerator and an 800-MeV accumulator ring. It simultaneously provides H{sup +} and H{sup -} beams to several user facilities that have their own distinctive requirements, e.g. intensity, chopping pattern, duty factor, etc.. This multibeam operation presents challenges both from the standpoint of meeting the individual requirements but also achieving good overall performance for the integrated operation. Various aspects of more recent operations including the some of these challenges will be discussed.

  11. Micro-Bubble Experiments at the Van de Graaff Accelerator

    SciTech Connect

    Sun, Z. J.; Wardle, Kent E.; Quigley, K. J.; Gromov, Roman; Youker, A. J.; Makarashvili, Vakhtang; Bailey, James; Stepinski, D. C.; Chemerisov, S. D.; Vandegrift, G. F.

    2015-02-01

    In order to test and verify the experimental designs at the linear accelerator (LINAC), several micro-scale bubble ("micro-bubble") experiments were conducted with the 3-MeV Van de Graaff (VDG) electron accelerator. The experimental setups included a square quartz tube, sodium bisulfate solution with different concentrations, cooling coils, gas chromatography (GC) system, raster magnets, and two high-resolution cameras that were controlled by a LabVIEW program. Different beam currents were applied in the VDG irradiation. Bubble generation (radiolysis), thermal expansion, thermal convection, and radiation damage were observed in the experiments. Photographs, videos, and gas formation (O2 + H2) data were collected. The micro-bubble experiments at VDG indicate that the design of the full-scale bubble experiments at the LINAC is reasonable.

  12. Nuclear effects in atmospheric and accelerator neutrino experiments

    SciTech Connect

    Chauhan, S.; Athar, M. Sajjad; Singh, S. K.

    2010-11-24

    We have studied the nuclear medium effects in the neutrino (antineutrino) induced interactions in nuclei at intermediate energy region. We have applied this study to calculate the event rates for atmospheric and accelerator neutrino experiments. The study of the nuclear effects has been done for the quasielastic lepton production and the charged current incoherent and coherent pion production processes.

  13. The Student Course Experience among Online, Accelerated, and Traditional Courses

    ERIC Educational Resources Information Center

    Bielitz, Colleen L.

    2016-01-01

    The demand by the public for a wider variety of course formats has led to complexity in determining a course's optimal delivery format as many faculty members still believe that online and accelerated courses do not offer students an equivalent experience to traditional face to face instruction. The purpose of this quantitative, comparative study…

  14. Constant Acceleration: Experiments with a Fan-Driven Dynamics Cart.

    ERIC Educational Resources Information Center

    Morse, Robert A.

    1993-01-01

    Describes the rebuilding of a Project Physics fan cart on a PASCO dynamics cart chassis for achieving greatly reduced frictional forces. Suggests four experiments for the rebuilt cart: (1) acceleration on a level track, (2) initial negative velocity, (3) different masses and different forces, and (4) inclines. (MVL)

  15. Accelerator-based Experiments For Introductory-level Undergraduates

    SciTech Connect

    Sanders, Justin M.

    2009-03-10

    Although accelerator based experiments for undergraduates are often considered only for junior or senior physics majors, introductory students can also benefit from them. Rutherford backscattering and a {sup 12}C(p,p){sup 12}C elastic scattering resonance can be presented in ways that are well-suited for students who have taken only an introductory physics course.

  16. Magnetohydrodynamic Particle Acceleration Processes: SSX Experiments, Theory, and Astrophysical Applications

    SciTech Connect

    Brown, Michael R.

    2006-11-16

    Project Title: Magnetohydrodynamic Particle Acceleration Processes: SSX Experiments, Theory, and Astrophysical Applications PI: Michael R. Brown, Swarthmore College The purpose of the project was to provide theoretical and modeling support to the Swarthmore Spheromak Experiment (SSX). Accordingly, the theoretical effort was tightly integrated into the SSX experimental effort. During the grant period, Michael Brown and his experimental collaborators at Swarthmore, with assistance from W. Matthaeus as appropriate, made substantial progress in understanding the physics SSX plasmas.

  17. Results of the SINGAP Neutral Beam Accelerator Experiment at JAEA

    NASA Astrophysics Data System (ADS)

    de Esch, H. P. L.; Svensson, L.; Inoue, T.; Taniguchi, M.; Umeda, N.; Kashiwagi, M.; Fubiani, G.

    2009-03-01

    IRFM (CEA Cadarache) and JAEA Naka have entered into a collaboration in order to test a SINGAP [1] accelerator at the JAEA Megavolt Test Facility (MTF) at Naka, Japan. Whereas at the CEA testbed the acceleration current was limited to 0.1 A, at JAEA 0.5 A is available. This allows the acceleration of 15 H- beamlets in SINGAP to be tested and a direct comparison between SINGAP and MAMuG [2] to be made. High-voltage conditioning in the SINGAP configuration has been quite slow, with 581 kV in vacuum achieved after 140 hours of conditioning. With 0.1 Pa of H2 gas present in the accelerator 787 kV could be achieved. The conditioning curve for MAMuG is 200 kV higher. SINGAP beam optics appears in agreement with calculation results. A beamlet divergence better than 5 mrad was obtained. SINGAP accelerates electrons to a higher energy than MAMuG. Measurements of the power intercepted on one of the electron dumps have been compared with EAMCC code [3] calculations. Based on the experiments described here, electron production by a SINGAP accelerator scaled up to ITER size was estimated to be too high for comfort

  18. First results of the plasma wakefield acceleration experiment at PITZ

    NASA Astrophysics Data System (ADS)

    Lishilin, O.; Gross, M.; Brinkmann, R.; Engel, J.; Grüner, F.; Koss, G.; Krasilnikov, M.; Martinez de la Ossa, A.; Mehrling, T.; Osterhoff, J.; Pathak, G.; Philipp, S.; Renier, Y.; Richter, D.; Schroeder, C.; Schütze, R.; Stephan, F.

    2016-09-01

    The self-modulation instability of long particle beams was proposed as a new mechanism to produce driver beams for proton driven plasma wakefield acceleration (PWFA). The PWFA experiment at the Photo Injector Test facility at DESY, Zeuthen site (PITZ) was launched to experimentally demonstrate and study the self-modulation of long electron beams in plasma. Key aspects for the experiment are the very flexible photocathode laser system, a plasma cell and well-developed beam diagnostics. In this contribution we report about the plasma cell design, preparatory experiments and the results of the first PWFA experiment at PITZ.

  19. A linear accelerator in the space: The beam experiment aboard rocket

    SciTech Connect

    O'Shea, P.G.; Butler, T.A.; Lynch, M.T.; McKenna, K.F.; Pongratz, M.B.

    1990-01-01

    On July 13, 1989 the BEAM experiment Aboard Rocket (BEAR) linear accelerator was successfully launched and operated in space. The flight demonstrated that a neutral hydrogen beam could be successfully propagated in an exoatmospheric environment. The accelerator, which was the result of an extensive collaboration between Los Alamos National Laboratory and industrial partners, was designed to produce a 10 mA (equivalent), 1 MeV neutral hydrogen beam in 50 {mu}s pulses at 5 Hz. The major components were a 30 keV H{sup {minus}} injector a 1 MeV radio frequency quadrupole, two 425 Mhz RF amplifiers, a gas cell neutralizer, beam optics, vacuum system and controls. The design was strongly constrained by the need for a lightweight rugged system that would survive the rigors of launch and operate autonomously. Following the flight the accelerator was recovered and operated again on the laboratory. 6 figs., 2 tabs.

  20. The JPL telerobot operator control station: Operational experiences

    NASA Technical Reports Server (NTRS)

    Kan, Edwin P.

    1990-01-01

    The Operator Control Station of the JPL/NASA Telerobot Demonstration System provides an efficient man-machine interface for the performance of telerobot tasks. Its hardware and software have been designed with high flexibility. It provides a feedback-rich interactive environment in which the Operator performs teleoperation tasks, robotic tasks, and telerobotic tasks with ease. The to-date operational experiences of this system, particularly related to the Object Designate Process and the Voice Input/Output Process are discussed.

  1. 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.

  2. The laser driven particle accelerator project: Theory and experiment

    SciTech Connect

    Plettner, T.; Byer, R.L. Smith, T.I.; Siemann, R.H. Huang, Y.C.

    1999-07-01

    A proof of principle experiment for laser driven electron acceleration from crossed laser beams in a dielectric loaded vacuum is being carried out at Stanford University. We seek to measure a maximum energy gain of about 250 keV for a 30{endash}35 MeV electron beam in one accelerator cell. We use laser pulses of a few picoseconds of duration from a regenerative Ti:sapphire laser amplifier at a wavelength of 800 nm in a laser-electron interaction distance of {approximately}1 mm. {copyright} {ital 1999 American Institute of Physics.}

  3. 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.

  4. SEE induced in SRAM operating in a superconducting electron linear accelerator environment

    NASA Astrophysics Data System (ADS)

    Makowski, D.; Mukherjee, Bhaskar; Grecki, M.; Simrock, Stefan

    2005-02-01

    Strong fields of bremsstrahlung photons and photoneutrons are produced during the operation of high-energy electron linacs. Therefore, a mixed gamma and neutron radiation field dominates the accelerators environment. The gamma radiation induced Total Ionizing Dose (TID) effect manifests the long-term deterioration of the electronic devices operating in accelerator environment. On the other hand, the neutron radiation is responsible for Single Event Effects (SEE) and may cause a temporal loss of functionality of electronic systems. This phenomenon is known as Single Event Upset (SEU). The neutron dose (KERMA) was used to scale the neutron induced SEU in the SRAM chips. Hence, in order to estimate the neutron KERMA conversion factor for Silicon (Si), dedicated calibration experiments using an Americium-Beryllium (241Am/Be) neutron standard source was carried out. Single Event Upset (SEU) influences the short-term operation of SRAM compared to the gamma induced TID effect. We are at present investigating the feasibility of an SRAM based real-time beam-loss monitor for high-energy accelerators utilizing the SEU caused by fast neutrons. This paper highlights the effects of gamma and neutron radiations on Static Random Access Memory (SRAM), placed at selected locations near the Superconducting Linear Accelerator driving the Vacuum UV Free Electron Laser (VUVFEL) of DESY.

  5. Results from T2K and accelerator oscillation experiments

    NASA Astrophysics Data System (ADS)

    Bronner, C.

    2012-08-01

    Various experiments use secondary neutrino beams produced by accelerators to study neutrino oscillations. In this article, we will review oscillation results from a number of those experiments (MINOS, OPERA), and focus more on results from T2K. This long baseline off-axis experiment uses a beam of muon neutrinos produced in J-PARC in Japan to study muon neutrino disappearance in order to measure atmospheric parameters, as well as studying electron neutrino appearance to measure the 13 mixing angle. We will present in particular very recent results of those measurements obtained by MINOS and T2K.

  6. High Power Operation of the JLab IR FEL Driver Accelerator

    SciTech Connect

    Kevin Beard; Stephen Benson; George Biallas; James Boyce; Donald Bullard; James Coleman; David Douglas; H. Dylla; Richard Evans; Pavel Evtushenko; Christopher Gould; Albert Grippo; Joseph Gubeli; David Hardy; Carlos Hernandez-Garcia; J. Hovater; Kevin Jordan; John Klopf; Rui Li; Steven Moore; George Neil; Benard Poelker; Thomas Powers; Joseph Preble; Robert Rimmer; Daniel Sexton; Michelle D. Shinn; Christopher Tennant; Richard Walker; Gwyn Williams; Shukui Zhang

    2007-08-01

    Operation of the JLab IR Upgrade FEL at CW powers in excess of 10 kW requires sustained production of high electron beam powers by the driver ERL. This in turn demands attention to numerous issues and effects, including: cathode lifetime; control of beamline and RF system vacuum during high current operation; longitudinal space charge; longitudinal and transverse matching of irregular/large volume phase space distributions; halo management; management of remnant dispersive effects; resistive wall, wake-field, and RF heating of beam vacuum chambers; the beam break up instability; the impact of coherent synchrotron radiation (both on beam quality and the performance of laser optics); magnetic component stability and reproducibility; and RF stability and reproducibility. We discuss our experience with these issues and describe the modus vivendi that has evolved during prolonged high current, high power beam and laser operation.

  7. Absolute acceleration measurements on STS-50 from the Orbital Acceleration Research Experiment (OARE)

    NASA Technical Reports Server (NTRS)

    Blanchard, Robert C.; Nicholson, John Y.; Ritter, James R.

    1994-01-01

    Orbital Acceleration Research Experiment (OARE) data on Space Transportation System (STS)-50 have been examined in detail during a 2-day time period. Absolute acceleration levels have been derived at the OARE location, the orbiter center-of-gravity, and at the STS-50 spacelab Crystal Growth Facility. During the interval, the tri-axial OARE raw telemetered acceleration measurements have been filtered using a sliding trimmed mean filter in order to remove large acceleration spikes (e.g., thrusters) and reduce the noise. Twelve OARE measured biases in each acceleration channel during the 2-day interval have been analyzed and applied to the filtered data. Similarly, the in situ measured x-axis scale factors in the sensor's most sensitive range were also analyzed and applied to the data. Due to equipment problem(s) on this flight, both y- and z-axis sensitive range scale factors were determined in a separate process using orbiter maneuvers and subsequently applied to the data. All known significant low-frequency corrections at the OARE location (i.e., both vertical and horizontal gravity-gradient, and rotational effects) were removed from the filtered data in order to produce the acceleration components at the orbiter center-of-gravity, which are the aerodynamic signals along each body axis. Results indicate that there is a force being applied to the Orbiter in addition to the aerodynamic forces. The OARE instrument and all known gravitational and electromagnetic forces have been reexamined, but none produces the observed effect. Thus, it is tentatively concluded that the orbiter is creating the environment observed. At least part of this force is thought to be due to the Flash Evaporator System.

  8. MIT January Operational Internship Experience 2011

    NASA Technical Reports Server (NTRS)

    DeLatte, Danielle; Furhmann, Adam; Habib, Manal; Joujon-Roche, Cecily; Opara, Nnaemeka; Pasterski, Sabrina Gonzalez; Powell, Christina; Wimmer, Andrew

    2011-01-01

    This slide presentation reviews the 2011 January Operational Internship experience (JOIE) program which allows students to study operational aspects of spaceflight, how design affects operations and systems engineering in practice for 3 weeks. Topics include: (1) Systems Engineering (2) NASA Organization (3) Workforce Core Values (4) Human Factors (5) Safety (6) Lean Engineering (7) NASA Now (8) Press, Media, and Outreach and (9) Future of Spaceflight.

  9. The Awful Truth About Zero-Gravity: Space Acceleration Measurement System; Orbital Acceleration Research Experiment

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Earth's gravity holds the Shuttle in orbit, as it does satellites and the Moon. The apparent weightlessness experienced by astronauts and experiments on the Shuttle is a balancing act, the result of free-fall, or continuously falling around Earth. An easy way to visualize what is happening is with a thought experiment that Sir Isaac Newton did in 1686. Newton envisioned a mountain extending above Earth's atmosphere so that friction with the air would be eliminated. He imagined a cannon atop the mountain and aimed parallel to the ground. Firing the cannon propels the cannonball forward. At the same time, Earth's gravity pulls the cannonball down to the surface and eventual impact. Newton visualized using enough powder to just balance gravity so the cannonball would circle the Earth. Like the cannonball, objects orbiting Earth are in continuous free-fall, and it appears that gravity has been eliminated. Yet, that appearance is deceiving. Activities aboard the Shuttle generate a range of accelerations that have effects similar to those of gravity. The crew works and exercises. The main data relay antenna quivers 17 times per second to prevent 'stiction,' where parts stick then release with a jerk. Cooling pumps, air fans, and other systems add vibration. And traces of Earth's atmosphere, even 200 miles up, drag on the Shuttle. While imperceptible to us, these vibrations can have a profound impact on the commercial research and scientific experiments aboard the Shuttle. Measuring these forces is necessary so that researchers and scientists can see what may have affected their experiments when analyzing data. On STS-107 this service is provided by the Space Acceleration Measurement System for Free Flyers (SAMS-FF) and the Orbital Acceleration Research Experiment (OARE). Precision data from these two instruments will help scientists analyze data from their experiments and eliminate outside influences from the phenomena they are studying during the mission.

  10. Simulator experiments: effects of NPP operator experience on performance

    SciTech Connect

    Beare, A.N.; Gray, L.H.

    1984-01-01

    During the FY83 research, a simulator experiment was conducted at the control room simulator for a GE Boiling Water Reactor (BWR) NPP. The research subjects were licensed operators undergoing requalification training and shift technical advisors (STAs). This experiment was designed to investigate the effects of senior reactor operator (SRO) experience, operating crew augmentation with an STA and practice, as a crew, upon crew and individual operator performance, in response to anticipated plant transients. Sixteen two-man crews of licensed operators were employed in a 2 x 2 factorial design. The SROs leading the crews were split into high and low experience groups on the basis of their years of experience as an SRO. One half of the high- and low-SRO experience groups were assisted by an STA. The crews responded to four simulated plant casualties. A five-variable set of content-referenced performance measures was derived from task analyses of the procedurally correct responses to the four casualties. System parameters and control manipulations were recorded by the computer controlling the simulator. Data on communications and procedure use were obtained from analysis of videotapes of the exercises. Questionnaires were used to collect subject biographical information and data on subjective workload during each simulated casualty. For four of the five performance measures, no significant differences were found between groups led by high (25 to 114 months) and low (1 to 17 months as an SRO) experience SROs. However, crews led by low experience SROs tended to have significantly shorter task performance times than crews led by high experience SROs. The presence of the STA had no significant effect on overall team performance in responding to the four simulated casualties. The FY84 experiments are a partial replication and extension of the FY83 experiment, but with PWR operators and simulator.

  11. Ultra-High Gradient Dielectric Wakefield Accelerator Experiments

    SciTech Connect

    Thompson, M. C.; Badakov, H.; Rosenzweig, J. B.; Travis, G.; Hogan, M.; Ischebeck, R.; Kirby, N.; Siemann, R.; Walz, D.; Muggli, P.; Scott, A.; Yoder, R.

    2006-11-27

    Ultra-high gradient dielectric wakefield accelerators are a potential option for a linear collider afterburner since they are immune to the ion collapse and electron/positron asymmetry problems implicit in a plasma based afterburner. The first phase of an experiment to study the performance of dielectric Cerenkov wakefield accelerating structures at extremely high gradients in the GV/m range has been completed. The experiment took advantage of the unique SLAC FFTB electron beam and its ultra-short pulse lengths and high currents (e.g., {sigma}z = 20 {mu}m at Q = 3 nC). The FFTB electron beam was successfully focused down and sent through short lengths of fused silica capillary tubing (ID = 200 {mu}m / OD = 325 {mu}m). The pulse length of the electron beam was varied to produce a range of electric fields between 2 and 20 GV/m at the inner surface of the dielectric tubes. We observed a sharp increase in optical emissions from the capillaries in the middle part of this surface field range which we believe indicates the transition between sustainable field levels and breakdown. If this initial interpretation is correct, the surfaced fields that were sustained equate to on axis accelerating field of several GV/m. In future experiments being developed for the SLAC SABER and BNL ATF we plan to use the coherent Cerenkov radiation emitted from the capillary tube as a field strength diagnostic and demonstrate GV/m range particle energy gain.

  12. Ultra-High Gradient Dielectric Wakefield Accelerator Experiments

    NASA Astrophysics Data System (ADS)

    Thompson, M. C.; Badakov, H.; Rosenzweig, J. B.; Travis, G.; Hogan, M.; Ischebeck, R.; Kirby, N.; Siemann, R.; Walz, D.; Muggli, P.; Scott, A.; Yoder, R.

    2006-11-01

    Ultra-high gradient dielectric wakefield accelerators are a potential option for a linear collider afterburner since they are immune to the ion collapse and electron/positron asymmetry problems implicit in a plasma based afterburner. The first phase of an experiment to study the performance of dielectric Cerenkov wakefield accelerating structures at extremely high gradients in the GV/m range has been completed. The experiment took advantage of the unique SLAC FFTB electron beam and its ultra-short pulse lengths and high currents (e.g., σz = 20 μm at Q = 3 nC). The FFTB electron beam was successfully focused down and sent through short lengths of fused silica capillary tubing (ID = 200 μm / OD = 325 μm). The pulse length of the electron beam was varied to produce a range of electric fields between 2 and 20 GV/m at the inner surface of the dielectric tubes. We observed a sharp increase in optical emissions from the capillaries in the middle part of this surface field range which we believe indicates the transition between sustainable field levels and breakdown. If this initial interpretation is correct, the surfaced fields that were sustained equate to on axis accelerating field of several GV/m. In future experiments being developed for the SLAC SABER and BNL ATF we plan to use the coherent Cerenkov radiation emitted from the capillary tube as a field strength diagnostic and demonstrate GV/m range particle energy gain.

  13. Ultra-High Gradient Dielectric Wakefield Accelerator Experiments

    SciTech Connect

    Thompson, M.C.; Badakov, H.; Rosenzweig, J.B.; Travish, G.; Hogan, M.; Ischebeck, R.; Kirby, N.; Siemann, R.; Walz, D.; Muggli, P.; Scott, A.; Yoder, R.; /LLNL, Livermore /UCLA /SLAC /Southern California U. /UC, Santa Barbara /Manhattan Coll., Riverdale

    2007-03-27

    Ultra-high gradient dielectric wakefield accelerators are a potential option for a linear collider afterburner since they are immune to the ion collapse and electron/positron asymmetry problems implicit in a plasma based afterburner. The first phase of an experiment to study the performance of dielectric Cerenkov wakefield accelerating structures at extremely high gradients in the GV/m range has been completed. The experiment took advantage of the unique SLAC FFTB electron beam and its ultra-short pulse lengths and high currents (e.g., {sigma}{sub z} = 20 {micro}m at Q = 3 nC). The FFTB electron beam was successfully focused down and sent through short lengths of fused silica capillary tubing (ID = 200 {micro}m/OD = 325 {micro}m). The pulse length of the electron beam was varied to produce a range of electric fields between 2 and 20 GV/m at the inner surface of the dielectric tubes. We observed a sharp increase in optical emissions from the capillaries in the middle part of this surface field range which we believe indicates the transition between sustainable field levels and breakdown. If this initial interpretation is correct, the surfaced fields that were sustained equate to on axis accelerating field of several GV/m. In future experiments being developed for the SLAC SABER and BNL ATF we plan to use the coherent Cerenkov radiation emitted from the capillary tube as a field strength diagnostic and demonstrate GV/m range particle energy gain.

  14. Ultra-High Gradient Dielectric Wakefield Accelerator Experiments

    SciTech Connect

    Thompson, M C; Badakov, H; Rosenzweig, J B; Travish, G; Hogan, M; Ischebeck, R; Kirby, N; Siemann, R; Walz, D; Muggli, P; Scott, A; Yoder, R

    2006-08-04

    Ultra-high gradient dielectric wakefield accelerators are a potential option for a linear collider afterburner since they are immune to the ion collapse and electron/positron asymmetry problems implicit in a plasma based afterburner. The first phase of an experiment to study the performance of dielectric Cerenkov wakefield accelerating structures at extremely high gradients in the GV/m range has been completed. The experiment took advantage of the unique SLAC FFTB electron beam and its ultra-short pulse lengths and high currents (e.g., {sigma}{sub z} = 20 {micro}m at Q = 3 nC). The FFTB electron beam was successfully focused down and sent through short lengths of fused silica capillary tubing (ID = 200 {micro}m/OD = 325 {micro}m). The pulse length of the electron beam was varied to produce a range of electric fields between 2 and 20 GV/m at the inner surface of the dielectric tubes. We observed a sharp increase in optical emissions from the capillaries in the middle part of this surface field range which we believe indicates the transition between sustainable field levels and breakdown. If this initial interpretation is correct, the surfaced fields that were sustained equate to on axis accelerating field of several GV/m. In future experiments being developed for the SLAC SABER and BNL ATF we plan to use the coherent Cerenkov radiation emitted from the capillary tube as a field strength diagnostic and demonstrate GV/m range particle energy gain.

  15. TRIDAQ systems in HEP experiments at LHC accelerator

    NASA Astrophysics Data System (ADS)

    Zagozdzińska, Agnieszka; Romaniuk, Ryszard S.; Poźniak, Krzysztof T.; Zalewski, Piotr

    2013-01-01

    The paper describes Trigger and Data Acquisition (TRIDAQ) systems of accelerator experiments for High Energy Physics. The background for physics research comprises assumptions of the Standard Model theory with basic extensions. On this basis, a structure of particle detector system is described, with emphasis on the following functional blocks: Front-End Electronics, Trigger and DAQ systems. The described solutions are used in the LHC experiments: ATLAS, ALICE, CMS and LHCb. They are also used in other accelerator experiments. Data storage and processing functionality is divided into two hardware systems: Trigger and Data Acquisition, that are dependent on each other. High input data rate impose relevant choices for the architecture and parameters of both systems. The key parameters include detailed system structure and its overall latency. Trigger structure is defined by the physics requirements and the storage capability of DAQ system. Both systems are designed to achieve the highest possible space and time resolution for particle detection. Trigger references are reviewed [1-43] as well as chosen accelerator research efforts origination in this country [44-83].

  16. Nova pulse power design and operational experience

    NASA Astrophysics Data System (ADS)

    Whitham, K.; Larson, D.; Merritt, B.; Christie, D.

    1987-01-01

    Nova is a 100 TW Nd++ solid state laser designed for experiments with laser fusion at Lawrence Livermore National Laboratory (LLNL). The pulsed power for Nova includes a 58 MJ capacitor bank driving 5336 flashlamps with millisecond pulses and subnanosecond high voltages for electro optics. This paper summarizes the pulsed power designs and the operational experience to date.

  17. RF ACCELERATING STRUCTURE FOR THE MUON COOLING EXPERIMENT.

    SciTech Connect

    CORLETT,J.; GREEN,M.; LI,D.; HOLTKAMP,N.; MORETTI,A.; KIRK,H.G.; PALMER,R.B.; ZHAO,Y.; SUMMERS,D.

    1999-03-29

    The ionization cooling of muons requires longitudinal acceleration of the muons after scattering in a hydrogen target. In order to maximize the accelerating voltage, we propose using linear accelerating structures with cells bounded by thin beryllium metal foils. This produces an on-axis field equivalent to the maximum surface field, whereas with beam-pipes the accelerating field is approximately half that of the peak surface field in the cavity. The muons interact only weakly with the thin foils. A {pi}/2 interleaved cavity structure has been chosen, with alternate cells coupled together externally, and the two groups of cells fed in quadrature. At present they are considering an operating temperature of 77K to gain a factor of at least two in Q-value over room temperature. The authors describe the design of the {pi}/2 interleaved cavity structure, design of an alternative {pi}-mode open structure, preliminary experimental results from a low-power test cavity, and plans for high-power testing.

  18. Theoretical analysis of acceleration measurements in a model of an operating wind turbine.

    SciTech Connect

    Adams, Douglas E.; Rumsey, Mark Allen; White, Jonathan Randall

    2010-04-01

    as opposed to a physical experiment to examine the merits of acceleration-based load identification methods is that models of the structural dynamics and aerodynamics enable one to compare estimates of the deflection and loading with actual values. Realistic wind conditions are applied to the wind turbine and used to estimate the operational displacement and acceleration of the rotor. The per-revolution harmonics dominate the displacement and acceleration response. Turbulent wind produces broadband excitation that includes both the harmonics and modal vibrations, such as the tower modes. Power Spectral Density estimates of the acceleration along the span of the rotor blades indicate that the edge modes may be coupled to the second harmonic.

  19. Vacuum system operating experience review for fusion applications

    SciTech Connect

    Cadwallader, L.C.

    1994-03-01

    This report presents a review of vacuum system operating experiences from particle accelerator, fusion experiment, space simulation chamber, and other applications. Safety relevant operating experiences and accident information are discussed. Quantitative order-of-magnitude estimates of vacuum system component failure rates and accident initiating event frequencies are presented for use in risk assessment, reliability, and availability studies. Safety concerns with vacuum systems are discussed, including personnel safety, foreign material intrusion, and factors relevant to vacuum systems being the primary confinement boundary for tritium and activated dusts. This information should be useful to fusion system designers and safety analysts, such as the team working on the Engineering Design Activities for the International Thermonuclear Experimental Reactor.

  20. Dielectric Wakefield Accelerator Experiments at the SABER Facility

    SciTech Connect

    Kanareykin, A.; Thompson, M.C.; Berry, M.K.; Blumenfeld, I.; Decker, F.J.; Hogan, M.J.; Ischebeck, R.; Iverson, R.H.; Kirby, N.A.; Siemann, Robert H.; Walz, D.R.; Badakov, H.; Cook, A.M.; Rosenzweig, J.B.; Tikhoplav, R.; Travish, G.; Muggli, P.; /Southern California U.

    2008-01-28

    Electron bunches with the unparalleled combination of high charge, low emittances, and short time duration, as first produced at the SLAC Final Focus Test Beam (FFTB), are foreseen to be produced at the SABER facility. These types of bunches have enabled wakefield driven accelerating schemes of multi-GV/m in plasmas. In the context of the Dielectric Wakefield Accelerators (DWA) such beams, having rms bunch length as short as 20 um, have been used to drive 100 um and 200 um ID hollow tubes above 20 GV/m surface fields. These FFTB tests enabled the measurement of a breakdown threshold in fused silica (with full data analysis still ongoing) [1]. With the construction and commissioning of the SABER facility at SLAC, new experiments would be made possible to test further aspects of DWAs including materials, tube geometrical variations, direct measurements of the Cerenkov fields, and proof of acceleration in tubes >10 cm in length. This collaboration will investigate breakdown thresholds and accelerating fields in new materials including CVD diamond. Here we describe the experimental plans, beam parameters, simulations, and progress to date as well as future prospects for machines based of DWA structures.

  1. Plasmas, Dielectrics and the Ultrafast: First Science and Operational Experience at FACET

    SciTech Connect

    Clarke, C.I.; Adli, E.; Corde, S.; Decker, F.J.; England, R.J.; Erickson, R.; Fisher, A.; Gessner, S.; Hast, C.; Hogan, M.J.; Li, S.Z.; Lipkowitz, N.; Litos, M.; Nosochkov, Y.; Seeman, J.; Sheppard, J.C.; Tudosa, I.; White, G.; Wienands, U.; Woodley, M.; Wu, Z.; /SLAC /UCLA

    2012-09-14

    FACET (Facility for Advanced Accelerator and Experimental Tests) is an accelerator R&D test facility that has been recently constructed at SLAC National Accelerator Laboratory. The facility provides 20 GeV, 3 nC electron beams, short (20 {micro}m) bunches and small (20 {micro}m wide) spot sizes, producing uniquely high power beams. FACET supports studies from many fields but in particular those of Plasma Wakefield Acceleration and Dielectric Wakefield Acceleration. FACET is also a source of THz radiation for material studies. We present the FACET design, initial operating experience and first science from the facility.

  2. Structure Loaded Vacuum Laser-Driven Particle Acceleration Experiments at SLAC

    SciTech Connect

    Plettner, T.; Byer, R.L.; Colby, E.R.; Cowan, B.M.; Ischebeck, R.; McGuinness, C.; Lincoln, M.R.; Sears, C.M.; Siemann, R.H.; Spencer, J.E.; /SLAC /Stanford U., Phys. Dept.

    2007-04-09

    We present an overview of the future laser-driven particle acceleration experiments. These will be carried out at the E163 facility at SLAC. Our objectives include a reconfirmation of the proof-of-principle experiment, a staged buncher laser-accelerator experiment, and longer-term future experiments that employ dielectric laser-accelerator microstructures.

  3. High luminosity operation of the Fermilab accelerator complex

    SciTech Connect

    Shekhar Mishra

    2003-07-15

    Run-II at Fermilab is progressing steadily. In the Run-II scheme, 36 antiproton bunches collide with 36 proton bunches at the CDF and D0 interaction regions in the Tevatron at 980 GeV per beam. The current status and performance of the Fermilab Accelerator complex is reviewed. The plan for Run-II, accelerator upgrades and integration of the Recycler in the accelerator chain will be presented.

  4. Recent Developments on ALICE (Accelerators and Lasers In Combined Experiments) at Daresbury Laboratory

    SciTech Connect

    Saveliev, Y M; Buckley, R K; Buckley, S R; Clarke, J A; Corlett, P A; Dunning, D J; Goulden, A R; Hill, S F; Jackson, F; Jamison, S P; Jones, J K; Jones, L B; Leonard, S; McIntosh, P A; McKenzie, J W; Middleman, K J; Militsyn, B L; Moss, A J; Muratori, B D; Orrett, J F; Pattalwar, S M; Phillips, P J; Scott, D J; Seddon, E A; Shepherd, B.J.A.; Smith, S L; Thompson, N; Wheelhouse, A E; Williams, P H; Harrison, P; Holder, D J; Holder, G M; Schofield, A L; Weightman, P; Williams, R L; Laundry, D; Powers, T; Priebe, G; Surman, M

    2010-05-01

    Progress made in ALICE (Accelerators and Lasers In Combined Experiments) commissioning and a summary of the latest experimental results are presented in this paper. After an extensive work on beam loading effects in SC RF linac (booster) and linac cavities conditioning, ALICE can now operate in full energy recovery mode at the bunch charge of 40pC, the beam energy of 30MeV and train lengths of up to 100us. This improved operation of the machine resulted in generation of coherently enhanced broadband THz radiation with the energy of several tens of uJ per pulse and in successful demonstration of the Compton Backscattering x-ray source experiment. The next steps in the ALICE scientific programme are commissioning of the IR FEL and start of the research on the first non-scaling FFAG accelerator EMMA. Results from both projects will be also reported.

  5. Buoyancy driven acceleration in a hospital operating room indoor environment

    NASA Astrophysics Data System (ADS)

    McNeill, James; Hertzberg, Jean; Zhai, John

    2011-11-01

    In hospital operating rooms, centrally located non-isothermal ceiling jets provide sterile air for protecting the surgical site from infectious particles in the room air as well as room cooling. Modern operating rooms are requiring larger temperature differences to accommodate increasing cooling loads for heat gains from medical equipment. This trend may lead to significant changes in the room air distribution patterns that may sacrifice the sterile air field across the surgical table. Quantitative flow visualization experiments using laser sheet illumination and RANS modeling of the indoor environment were conducted to demonstrate the impact of the indoor environment thermal conditions on the room air distribution. The angle of the jet shear layer was studied as function of the area of the vena contracta of the jet, which is in turn dependent upon the Archimedes number of the jet. Increases in the buoyancy forces cause greater air velocities in the vicinity of the surgical site increasing the likelihood of deposition of contaminants in the flow field. The outcome of this study shows the Archimedes number should be used as the design parameter for hospital operating room air distribution in order to maintain a proper supply air jet for covering the sterile region. This work is supported by ASHRAE.

  6. Hypervelocity macroparticle accelerator experiments at CEM-UT

    NASA Astrophysics Data System (ADS)

    Weeks, D. A.; Weldon, W. F.; Zowarka, R. C., Jr.

    1991-01-01

    Railgun experiments designed to accelerate projectile masses of 2 to 5 g to velocities greater than 6 km/s were performed. Two parallel rail-type accelerators with 12.7-mm square bores were used for the experiments. One gun is 2 m long and has Mo rails and Al2O3 insulators. The other is 1 m long and has Mo rails and granite insulators. The greatest velocity achieved was 5.1 km/s. The following ideas to enhance performance were tested: stiff-gun structures to reduce plasma leakage and rail movement, refractory bore materials to reduce ablation and frictional losses, and prefilling the gun bore with gases to eliminate precursor arcs. After three experiments with the 2-m-long launcher at peak currents 660-780 kA, a gun barrel with 96 percent Al2O3 insulators and 99.9 percent Mo rails (hydraulically contained and preloaded) has survived with minimal damage and no degradation of seals. This launcher configuration is capable of maintaining 0.4 torr rough vacuum for over 1 h after disconnecting the roughing pump used to evacuate the gun.

  7. Some experiences with BEPCII SRF system operation

    NASA Astrophysics Data System (ADS)

    Huang, Tong-ming; Lin, Hai-ying; Sun, Yi; Dai, Jian-ping; Wang, Guang-wei; Pan, Wei-min Li, Zhong-quan; Ma, Qiang; Wang, Qun-yao; Zhao, Guang-yuan; Mi, Zheng-hui; Sha, Peng

    2016-06-01

    The Superconducting Radio Frequency (SRF) system of the upgrade project of the Beijing Electron Positron Collider (BEPCII) has been in operation for almost 8 years. During operation, many problems have been encountered, such as excessive heating of the power couplers, frequent beam trips during high intensity colliding, false arc interlock trigger and so on. Among them, some has been solved successfully, some have been alleviated. This paper will describe some experiences with BEPCII SRF system operation, including the symptoms, causes and solutions of problems.

  8. A small scale accelerator driven subcritical assembly development and demonstration experiment at LAMPF

    SciTech Connect

    Wender, S.A.; Venneri, F.; Bowman, C.D.; Arthur, E.D.; Heighway, E.A.; Beard, C.A.; Bracht, R.R.; Buksa, J.J.; Chavez, W.; DeVolder, B.G.

    1994-10-01

    A small scale experiment is described that will demonstrate many of the aspects of accelerator-driven transmutation technology. This experiment uses the high-power proton beam from the Los Alamos Meson Physics Facility accelerator and will be located in the Area-A experimental hall. Beam currents of up to 1 mA will be used to produce neutrons with a molten lead target. The target is surrounded by a molten salt and graphite moderator blanket. Fissionable material can be added to the molten salt to demonstrate plutonium burning or transmutation of commercial spent fuel or energy production from thorium. The experiment will be operated at power levels up to 5 MW{sub t}.

  9. Analysis of Capillary Guided Laser Plasma Accelerator Experiments at LBNL

    SciTech Connect

    Nakamura, K.; Esarey, E.; Leemans, W. P.; Gonsalves, A. J.; Panasenko, D.; Toth, Cs.; Geddes, C. G. R.; Schroeder, C. B.; Lin, C.

    2009-01-22

    Laser wakefield acceleration experiments were carried out by using a hydrogen-filled capillary discharge waveguide. For a 15 mm long, 200 {mu}m diameter capillary, quasi-monoenergetic e-beams up to 300 MeV were observed. By de-tuning discharge delay from optimum guiding performance, self-trapping was found to be stabilized. For a 33 mm long, 300 {mu}m capillary, a parameter regime with high energy electron beams, up to 1 GeV, was found. In this regime, the electron beam peak energy was correlated with the amount of trapped electrons.

  10. Analysis of Capillary Guided Laser Plasma Accelerator Experiments at LBNL

    SciTech Connect

    Advanced Light Source; Nakamura, Kei; Gonsalves, Anthony; Panasenko, Dmitriy; Lin, Chen; Toth, Csaba; Geddes, Cameron; Schroeder, Carl; Esarey, Eric; Leemans, Wim

    2008-09-29

    Laser wakefield acceleration experiments were carried out by using a hydrogen-filledcapillary discharge waveguide. For a 15 mm long, 200 mu m diameter capillary, quasi-monoenergetic e-beams up to 300 MeV were observed. By de-tuning discharge delay from optimum guiding performance, self-trapping was found to be stabilized. For a 33 mm long, 300 mu m capillary, a parameter regime with high energy electron beams, up to 1 GeV, was found. In this regime, the electron beam peak energy was correlated with the amount of trapped electrons.

  11. A prototype of a beam steering assistant tool for accelerator operations

    SciTech Connect

    M. Bickley; P. Chevtsov

    2006-10-24

    The CEBAF accelerator provides nuclear physics experiments at Jefferson Lab with high quality electron beams. Three experimental end stations can simultaneously receive the beams with different energies and intensities. For each operational mode, the accelerator setup procedures are complicated and require very careful checking of beam spot sizes and positions on multiple beam viewers. To simplify these procedures and make them reproducible, a beam steering assistant GUI tool has been created. The tool is implemented as a multi-window control screen. The screen has an interactive graphical object window, which is an overlay on top of a digitized live video image from a beam viewer. It allows a user to easily create and edit any graphical objects consisting of text, ellipses, and lines, right above the live beam viewer image and then save them in a file that is called a beam steering template. The template can show, for example, the area within which the beam must always be on the viewer. Later, this template can be loaded in the interactive graphical object window to help accelerator operators steer the beam to the specified area on the viewer.

  12. High Temperature μSR Experiments for Accelerator Developments

    NASA Astrophysics Data System (ADS)

    Ohmori, Chihiro; Koda, Akihiro; Miyake, Yasuhiro; Nishiyama, Kusuo; Shimomura, Koichiro; Schnase, Alexander; Ezura, Eiji; Hara, Keigo; Hasegawa, Katsushi; Nomura, Masahiro; Shimada, Taihei; Takata, Koji; Tamura, Fumihiko; Toda, Makoto; Yamamoto, Masanobu; Yoshii, Masahito

    High temperature μSR is a powerful technique to study magnetic materials. In J-PARC accelerator synchrotrons, the Rapid Cycling Synchrotron (RCS) and Main Ring (MR), a unique magnetic alloy-loaded cavity is used for the beam acceleration and much higher field gradient has been achieved. Such high field gradient cavities made a compact RCS possible by reducing the length for beam acceleration. Now, further upgrades of the J-PARC, RF cavities with higher RF voltage and less power loss in the magnetic core are needed for the MR. For the improvements of the magnetic property of magnetic alloy core, the high temperature μSR (muon Spin Rotation/Relaxation) was used to investigate the crystallization process of the material. Based on the measurement results, the test production of the large ring cores of a magnetic alloy, FT3L, was tried. The FT3L is the magnetic alloy which has two times better performance than the present one, FT3M. For the FT3L production, the magnetic annealing is needed to control the easy-magnetized axis of the crystalline. After the success of the test production, a mass production was started in the industry to replace all existing cavities in the MR. The first 5-cell FT3L cavity is assembled for the bench test before the installation in the accelerator tunnel. By the new cavities, the total RF voltage of J-PARC MR will be doubled to increase the beam power for neutrino experiment. In future, the cavities will be also used for the RCS to increase the beam power beyond 1 MW.

  13. Occupational Work Experience. Manual of Operation.

    ERIC Educational Resources Information Center

    Ohio State Dept. of Education, Columbus. Div. of Vocational and Adult Education.

    This manual is designed to assist school personnel, employers, parents/guardians, and students in understanding the policies and procedures required to operate effective occupational work experience (OWE) programs. The OWE mission statement appears first. Chapter I describes the OWE program, its structure, types of program organization, and…

  14. Neutrino horn power supply operational experience

    SciTech Connect

    Stillman, P.; Sandberg, J.; Carroll, A.S.; Leonhardt, W.; Monaghan, R.; Pearson, C.; Pendzich, A.; Ryan, G.; Sims, W.P.; Smith, G.A.

    1987-01-01

    The operational experiences required to run the 300 kA pulsed power supply at Brookhaven National Laboratory are given. Various interlocks and monitoring circuits are described and the impact on system reliability are discussed. The initial conditioning process of the power supply during startup is described.

  15. Operational experiences of a downhole steam generator

    NASA Astrophysics Data System (ADS)

    Marshall, B. W.

    The US Department of Energy supported the development of downhole steam generators for enhanced oil recovery as a part of Project DEEP STEAM. A final step in the development program was to deploy a downhole steam generator in the field to demonstrate its reliable operation and to evaluate the effect of the combined steam/exhaust products effluent on the reservoir. Sandia National Laboratories entered into an agreement with the City of Long Beach to place two direct contact, high pressure combustors in the Wilmington Field in Long Beach, California. These units one downhole and the other on the surface, have now been operated for a few months and gas communication with the production wells measured. The operational experience of this field experiment are discussed.

  16. Operational experiences of a downhole steam generator

    SciTech Connect

    Marshall, B.W.

    1982-01-01

    The US Department of Energy has supported the development of downhole steam generators for enhanced oil recovery as a part of Project DEEP STEAM. A final step in the development program was to deploy a downhole steam generator (DHSG) in the field to demonstrate its reliable operation and to evaluate the effect of the combined steam/exhaust products effluent on the reservoir. Sandia National Laboratories entered into an agreement with the City of Long Beach to place two direct contact, high pressure combustors in the Wilmington Field in Long Beach, California. These units one downhole and the other on the surface, have now been operated for a few months and gas communication with the production wells measured. The operational experience of this field experiment are discussed.

  17. Subpanel on accelerator-based neutrino oscillation experiments

    SciTech Connect

    1995-09-01

    Neutrinos are among nature`s fundamental constituents, and they are also the ones about which we know least. Their role in the universe is widespread, ranging from the radioactive decay of a single atom to the explosions of supernovae and the formation of ordinary matter. Neutrinos might exhibit a striking property that has not yet been observed. Like the back-and-forth swing of a pendulum, neutrinos can oscillate to-and-from among their three types (or flavors) if nature provides certain conditions. These conditions include neutrinos having mass and a property called {open_quotes}mixing.{close_quotes} The phenomenon is referred to as neutrino oscillations. The questions of the origin of neutrino mass and mixing among the neutrino flavors are unsolved problems for which the Standard Model of particle physics holds few clues. It is likely that the next critical step in answering these questions will result from the experimental observation of neutrino oscillations. The High Energy Physics Advisory Panel (HEPAP) Subpanel on Accelerator-Based Neutrino Oscillation Experiments was charged to review the status and discovery potential of ongoing and proposed accelerator experiments on neutrino oscillations, to evaluate the opportunities for the U.S. in this area of physics, and to recommend a cost-effective plan for pursuing this physics, as appropriate. The complete charge is provided in Appendix A. The Subpanel studied these issues over several months and reviewed all the relevant and available information on the subject. In particular, the Subpanel reviewed the two proposed neutrino oscillation programs at Fermi National Accelerator Laboratory (Fermilab) and at Brookhaven National Laboratory (BNL). The conclusions of this review are enumerated in detail in Chapter 7 of this report. The recommendations given in Chapter 7 are also reproduced in this summary.

  18. Hyper-velocity impact experiments with electrostatic dust accelerators

    NASA Astrophysics Data System (ADS)

    Mocker, Anna; Aust, Thomas; Bugiel, Sebastian; Hillier, Jonathan; Hornung, Klaus; Li, Yan-Wei; Strack, Heiko; Ralf, Srama

    2015-06-01

    Hypervelocity impacts (HVI) of micrometer-sized particles play an important role in a variety of fields such as the investigation of matter at extreme pressures and temperatures, shock waves in solid bodies, planetology and cosmic dust. The physical phenomena occurring upon impact are fragmentation and cratering, shock waves, the production of neutral and ionized gas, and light flashes. Advanced analysis techniques promise new insights into short time-scale high-pressure states of matter, requiring the production of high speed projectiles. Electrostatic accelerators act as a source of micrometer and sub-micrometer particles as projectiles for HVI experiments. This paper describes an HVI facility, capable of accelerating particles to over 100 km/s, currently located at the Max Planck Institute for Nuclear Physics in Heidelberg, together with planned improvements. The facility is about to be relocated to the University of Stuttgart. This is an opportunity to enhance the facility to meet the requirements of future experimental campaigns, necessary to better understand the micrometeoroid hypervelocity impact process and develop new in situ dust experiments. We will present the design of the new facility and the planned enhancements, including new diagnostic apparatus.

  19. The Deep Impact Network Experiment Operations Center

    NASA Technical Reports Server (NTRS)

    Torgerson, J. Leigh; Clare, Loren; Wang, Shin-Ywan

    2009-01-01

    Delay/Disruption Tolerant Networking (DTN) promises solutions in solving space communications challenges arising from disconnections as orbiters lose line-of-sight with landers, long propagation delays over interplanetary links, and other phenomena. DTN has been identified as the basis for the future NASA space communications network backbone, and international standardization is progressing through both the Consultative Committee for Space Data Systems (CCSDS) and the Internet Engineering Task Force (IETF). JPL has developed an implementation of the DTN architecture, called the Interplanetary Overlay Network (ION). ION is specifically implemented for space use, including design for use in a real-time operating system environment and high processing efficiency. In order to raise the Technology Readiness Level of ION, the first deep space flight demonstration of DTN is underway, using the Deep Impact (DI) spacecraft. Called the Deep Impact Network (DINET), operations are planned for Fall 2008. An essential component of the DINET project is the Experiment Operations Center (EOC), which will generate and receive the test communications traffic as well as "out-of-DTN band" command and control of the DTN experiment, store DTN flight test information in a database, provide display systems for monitoring DTN operations status and statistics (e.g., bundle throughput), and support query and analyses of the data collected. This paper describes the DINET EOC and its value in the DTN flight experiment and potential for further DTN testing.

  20. Analysis of the acceleration region in a circulating fluidized bed riser operating above fast fluidization velocities

    SciTech Connect

    Monazam, E.R.; Shadle, L.J.

    2008-11-05

    In commercial circulating fluidized bed (CFB) processes the acceleration zone greatly contributes to solids mixing, gas and solids dispersion, and particle residence times. A new analysis was developed to describe the relative gas-solids concentration in the acceleration region of a transport system with air as the fluidizing agent for Geldart-type B particles. A theoretical expression was derived from a drag relationship and momentum and continuity equations to describe the evolution of the gas-solids profile along the axial direction. The acceleration zone was characterized using nondimensional analysis of the continuum equations (balances of masses and momenta) that described multiphase flows. In addition to acceleration length, the boundary condition for the solids fraction at the bottom of the riser and the fully developed regions were measured using an industrial scale CFB of 0.3 m diameter and 15 m tall. The operating factors affecting the flow development in the acceleration region were determined for three materials of various sizes and densities in core annular and dilute regimes of the riser. Performance data were taken from statistically designed experiments over a wide range of Fr (0.5-39), Re (8-600), Ar (29-3600), load ratio (0.2-28), riser to particle diameter ratio (375-5000), and gas to solids density ratio (138-1381). In this one-dimensional system of equations, velocities and solid fractions were assumed to be constant over any cross section. The model and engineering correlations were compared with literature expressions to assess their validity and range of applicability. These expressions can be used as tools for simulation and design of a CFB riser and can also be easily coupled to a kinetics model for process simulation.

  1. GRAS NRT Precise Orbit Determination: Operational Experience

    NASA Technical Reports Server (NTRS)

    MartinezFadrique, Francisco M.; Mate, Alberto Agueda; Rodriquez-Portugal, Francisco Sancho

    2007-01-01

    EUMETSAT launched the meteorological satellite MetOp-A in October 2006; it is the first of the three satellites that constitute the EUMETSAT Polar System (EPS) space segment. This satellite carries a challenging and innovative instrument, the GNSS Receiver for Atmospheric Sounding (GRAS). The goal of the GRAS instrument is to support the production of atmospheric profiles of temperature and humidity with high accuracy, in an operational context, based on the bending of the GPS signals traversing the atmosphere during the so-called occultation periods. One of the key aspects associated to the data processing of the GRAS instrument is the necessity to describe the satellite motion and GPS receiver clock behaviour with high accuracy and within very strict timeliness limitations. In addition to these severe requirements, the GRAS Product Processing Facility (PPF) must be integrated in the EPS core ground segment, which introduces additional complexity from the data integration and operational procedure points of view. This paper sets out the rationale for algorithm selection and the conclusions from operational experience. It describes in detail the rationale and conclusions derived from the selection and implementation of the algorithms leading to the final orbit determination requirements (0.1 mm/s in velocity and 1 ns in receiver clock error at 1 Hz). Then it describes the operational approach and extracts the ideas and conclusions derived from the operational experience.

  2. Operating procedures: Fusion Experiments Analysis Facility

    SciTech Connect

    Lerche, R.A.; Carey, R.W.

    1984-03-20

    The Fusion Experiments Analysis Facility (FEAF) is a computer facility based on a DEC VAX 11/780 computer. It became operational in late 1982. At that time two manuals were written to aid users and staff in their interactions with the facility. This manual is designed as a reference to assist the FEAF staff in carrying out their responsibilities. It is meant to supplement equipment and software manuals supplied by the vendors. Also this manual provides the FEAF staff with a set of consistent, written guidelines for the daily operation of the facility.

  3. Operational experience of the OC-OTEC experiments at NELH

    SciTech Connect

    Link, H

    1989-02-01

    The Solar Energy Research Institute, under funding and program direction from the US Department of Energy, has been operating a small-scale test apparatus to investigate key components of open- cycle ocean thermal energy conversion (OC-OTEC). The apparatus started operations in October 1987 and continues to provide valuable information on heat-and mass-transfer processes in evaporators and condensers, gas sorption processes as seawater is depressurized and repressurized, and control and instrumentation characteristics of open-cycle systems. Although other test facilities have been used to study some of these interactions, this is the largest apparatus of its kind to use seawater since Georges Claude`s efforts in 1926. The information obtained from experiments conducted in this apparatus is being used to design a larger scale experiment in which a positive net power production is expected to be demonstrated for the first time with OC-OTEC. This paper describes the apparatus, the major tests conducted during its first 18 months of operation, and the experience gained in OC-OTEC system operation. 13 refs., 8 figs.

  4. Nova power systems: status and operating experience

    SciTech Connect

    Whitham, K.; Merritt, B.T.; Gritton, D.G.; Smart, A.J.; Holloway, R.W.; Oicles, J.A.

    1983-11-28

    This paper describes the pulse power systems that are used in these lasers; the status and the operating experiences. The pulsed power system for the Nova Laser is comprised of several distinct technology areas. The large capacitor banks for driving flashlamps that excite the laser glass is one area, the fast pulsers that drive pockels cell shutters is another area, and the contol system for the pulsed power is a third. This paper discusses the capacitor banks and control systems.

  5. Continuous Air Monitor Operating Experience Review

    SciTech Connect

    L. C. Cadwallader; S. A. Bruyere

    2008-09-01

    Continuous air monitors (CAMs) are used to sense radioactive particulates in room air of nuclear facilities. CAMs alert personnel of potential inhalation exposures to radionuclides and can also actuate room ventilation isolation for public and environmental protection. This paper presents the results of a CAM operating experience review of the DOE Occurrence Reporting and Processing System (ORPS) database from the past 18 years. Regulations regarding these monitors are briefly reviewed. CAM location selection and operation are briefly discussed. Operating experiences reported by the U.S. Department of Energy and in other literature sources were reviewed to determine the strengths and weaknesses of these monitors. Power losses, human errors, and mechanical issues cause the majority of failures. The average “all modes” failure rate is 2.65E-05/hr. Repair time estimates vary from an average repair time of 9 hours (with spare parts on hand) to 252 hours (without spare parts on hand). These data should support the use of CAMs in any nuclear facility, including the National Ignition Facility and the international ITER experiment.

  6. Cryogenic system operational experience at SNS

    NASA Astrophysics Data System (ADS)

    Howell, M.; DeGraff, B.; Kim, S.-H.; Morris, B.; Neustadt, T.; Strong, H.

    2015-12-01

    The helium cryogenic system at Spallation Neutron Source (SNS) provides cooling to 81 superconducting radio frequency cavities. During the first ten years of operation, much operational experience and lessons learned have been gained. The lessons learned include integrated system issues as well as component failures in the areas of mechanical, electrical and controls. Past issues that have been corrected as well as current issues in the system will be detailed in this paper. In 2009, a Process Failure Modes and Effects Analysis (PFMEA) was completed as a way to identify high risk items and prioritize efforts. Since 2009, the progress on mitigating the identified high risk items has been tracked. The results of the PFMEA and the progress made in reducing risk to the cryogenic system operation will be detailed in this paper.

  7. Operational Experience from Solar Thermal Energy Projects

    NASA Technical Reports Server (NTRS)

    Cameron, C. P.

    1984-01-01

    Over the past few years, Sandia National Laboratories were involved in the design, construction, and operation of a number of DOE-sponsored solar thermal energy systems. Among the systems currently in operation are several industrial process heat projects and the Modular Industrial Solar Retrofit qualification test systems, all of which use parabolic troughs, and the Shenandoah Total Energy Project, which uses parabolic dishes. Operational experience has provided insight to both desirable and undesirable features of the designs of these systems. Features of these systems which are also relevant to the design of parabolic concentrator thermal electric systems are discussed. Other design features discussed are system control functions which were found to be especially convenient or effective, such as local concentrator controls, rainwash controls, and system response to changing isolation. Drive systems are also discussed with particular emphasis of the need for reliability and the usefulness of a manual drive capability.

  8. Characteristics of a 30-cm thruster operated with small hole accelerator grid ion optics

    NASA Technical Reports Server (NTRS)

    Vahrenkamp, R. P.

    1976-01-01

    Small hole accelerator grid ion optical systems have been tested as a possible means of improving 30-cm ion thruster performance. The effects of small hole grids on the critical aspects of thruster operation including discharge chamber performance, doubly-charged ion concentration, effluent beam characteristics, and plasma properties have been evaluated. In general, small hole accelerator grids are beneficial in improving thruster performance while maintaining low double ion ratios. However, extremely small accelerator aperture diameters tend to degrade beam divergence characteristics. A quantitative discussion of these advantages and disadvantages of small hole accelerator grids, as well as resulting variations in thruster operation characteristics, is presented.

  9. Tested by Fire - How two recent Wildfires affected Accelerator Operations at LANL

    SciTech Connect

    Spickermann, Thomas

    2012-08-01

    In a little more than a decade two large wild fires threatened Los Alamos and impacted accelerator operations at LANL. In 2000 the Cerro Grande Fire destroyed hundreds of homes, as well as structures and equipment at the DARHT facility. The DARHT accelerators were safe in a fire-proof building. In 2011 the Las Conchas Fire burned about 630 square kilometers (250 square miles) and came dangerously close to Los Alamos/LANL. LANSCE accelerator operations Lessons Learned during Las Conchas fire: (1) Develop a plan to efficiently shut down the accelerator on short notice; (2) Establish clear lines of communication in emergency situations; and (3) Plan recovery and keep squirrels out.

  10. From US NAVY Mate to Division Leader for Operations - Requirements, Development and Career Paths of LANL/LANSCE Accelerator Operators

    SciTech Connect

    Spickermann, Thomas

    2012-07-26

    There are opportunities for advancement within the team. Operators advance by: (1) Becoming fully qualified - following the LANSCE Accelerator Operator Training Manual, Operator trainees go through 5 levels of qualification, from Radiation Security System to Experimental Area Operator. Must obtain Knowledge and Performance checkouts by an OSS or AOSS, and an End-of-Card checkout by the team leader or RSS engineer (level I). Program was inspired by US NAVY qualification program for nuclear reactor operators. Time to complete: 2-2.5 years. (2) Fully qualified operators are eligible to apply for vacant (OSS)/AOSS positions; and (3) Alternatively, experienced operators can sign up for the voluntary Senior Operator Qualification Program. They must demonstrate in-depth knowledge of all areas of the accelerator complex. Time to complete is 2-3 years (Minimum 4 years from fully qualified). Eligible for promotion to level between qualified operator and AOSS.

  11. Wakefield Simulations for the Laser Acceleration Experiment at SLAC

    SciTech Connect

    Ng, Johnny

    2012-04-18

    Laser-driven acceleration in dielectric photonic band gap structures can provide gradients on the order of GeV/m. The small transverse dimension of the structure, on the order of the laser wavelength, presents interesting wakefield-related issues. Higher order modes can seriously degrade beam quality, and a detailed understanding is needed to mitigate such effects. On the other hand, wakefields also provide a direct way to probe the interaction of a relativistic bunch with the synchronous modes supported by the structure. Simulation studies have been carried out as part of the effort to understand the impact on beam dynamics, and to compare with data from beam experiments designed to characterize candidate structures. In this paper, we present simulation results of wakefields excited by a sub-wavelength bunch in optical photonic band gap structures.

  12. Accelerating multidimensional NMR and MRI experiments using iterated maps

    NASA Astrophysics Data System (ADS)

    Barrett, Sean; Frey, Merideth; Sethna, Zachary; Manley, Gregory; Sengupta, Suvrajit; Zilm, Kurt; Loria, J. Patrick

    2014-03-01

    Techniques that accelerate data acquisition without sacrificing the advantages of fast Fourier transform (FFT) reconstruction could benefit a wide variety of magnetic resonance experiments. Here we discuss an approach for reconstructing multidimensional nuclear magnetic resonance (NMR) spectra and MR images from sparsely-sampled time domain data, by way of iterated maps. This method exploits the computational speed of the FFT algorithm and is done in a deterministic way, by reformulating any a priori knowledge or constraints into projections, and then iterating. In this paper we explain the motivation behind this approach, the formulation of the specific projections, the benefits of using a `QUasi-Even Sampling, plus jiTter' (QUEST) sampling schedule, and various methods for handling noise. Applying the iterated maps method to real 2D NMR and 3D MRI of solids data, we show that it is flexible and robust enough to handle large data sets with significant noise and artifacts.

  13. Accelerating multidimensional NMR and MRI experiments using iterated maps

    NASA Astrophysics Data System (ADS)

    Frey, Merideth A.; Sethna, Zachary M.; Manley, Gregory A.; Sengupta, Suvrajit; Zilm, Kurt W.; Loria, J. Patrick; Barrett, Sean E.

    2013-12-01

    Techniques that accelerate data acquisition without sacrificing the advantages of fast Fourier transform (FFT) reconstruction could benefit a wide variety of magnetic resonance experiments. Here we discuss an approach for reconstructing multidimensional nuclear magnetic resonance (NMR) spectra and MR images from sparsely-sampled time domain data, by way of iterated maps. This method exploits the computational speed of the FFT algorithm and is done in a deterministic way, by reformulating any a priori knowledge or constraints into projections, and then iterating. In this paper we explain the motivation behind this approach, the formulation of the specific projections, the benefits of using a ‘QUasi-Even Sampling, plus jiTter' (QUEST) sampling schedule, and various methods for handling noise. Applying the iterated maps method to real 2D NMR and 3D MRI of solids data, we show that it is flexible and robust enough to handle large data sets with significant noise and artifacts.

  14. ISAC SC-LINAC PHASE-II HELIUM REFRIGERATOR COMMISSIONING AND FIRST OPERATIONAL EXPERIENCE AT TRIUMF

    SciTech Connect

    Sekachev, I.; Kishi, D.; Laxdal, R. E.

    2010-04-09

    ISAC Phase-II is an upgrade of the radioactive isotope superconducting linear accelerator, SC-linac, at TRIUMF. The Phase-I section of the accelerator, medium-beta, is operational and is cooled with a 600 W helium refrigerator, commissioned in March 2005. An identical refrigerator is being used with the Phase-II segment of the accelerator; which is now under construction. The second refrigerator has been commissioned and tested with the Phase-I section of the linac and is used for Phase-II linac development, including new SC-cavity performance tests. The commissioning of the Phase-II refrigeration system and recent operational experience is presented.

  15. Isac Sc-Linac Phase-II Helium Refrigerator Commissioning and First Operational Experience at Triumf

    NASA Astrophysics Data System (ADS)

    Sekachev, I.; Kishi, D.; Laxdal, R. E.

    2010-04-01

    ISAC Phase-II is an upgrade of the radioactive isotope superconducting linear accelerator, SC-linac, at TRIUMF. The Phase-I section of the accelerator, medium-beta, is operational and is cooled with a 600 W helium refrigerator, commissioned in March 2005. An identical refrigerator is being used with the Phase-II segment of the accelerator; which is now under construction. The second refrigerator has been commissioned and tested with the Phase-I section of the linac and is used for Phase-II linac development, including new SC-cavity performance tests. The commissioning of the Phase-II refrigeration system and recent operational experience is presented.

  16. OTEC-1 test operations experience. Final report

    SciTech Connect

    Hoshide, R.K.; Klein, A.; Polino, D.L.; Poucher, F.W.

    1983-07-15

    During Phase III, the complete integrated system was operated, and information was obtained on the performance of the test article, the performance of the seawater and ammonia systems, the operation of the platform and moor systems, the effects of biofouling countermeasures, and the effects of the OTEC cycle on the environment. After several months spent in completing construction of the test system and checking out and repairing the various systems, 4 months of test operations were conducted before funding constraints caused the discontinuation of the test program. Plans were made for long-term storage and/or disposition of the test facility. The OEC test platform is currently located at Pearl Harbor, in the US Navy Inactive Reserve Fleet anchorage. The CWP was placed in underwater storage adjacent to the moor, awaiting a decision on final disposition. In October 1982, the CWP was recovered and custody given to the State of Hawaii. Although the test period lasted only about 4 months, deployment and at-sea operation of a large-scale OTEC plant was demonstrated, and information was obtained towards satisfying each of the objectives of the OTEC-1 project. This document summarizes the OTEC-1 test operations experience, discusses technical lessons learned, and makes recommendations for future OTEC plants.

  17. From the Discovery of Radioactivity to the First Accelerator Experiments

    NASA Astrophysics Data System (ADS)

    Walter, Michael

    The chapter reviews the historical phases of cosmic ray research from the very beginning around 1900 until the 1940s when first particle accelerators replaced cosmic particles as source for elementary particle interactions. In opposite to the discovery of X-rays or the ionising α-, β- and γ-rays, it was an arduous path to the definite acceptance of the new radiation. The starting point was the explanation that air becomes conductive by the ionising radiation of radioactive elements in the surroundings. In the following years the penetration power of the radiation was studied with the result, that there seems be a component harder than the known γ-rays. Victor F. Hess did in 1912 the key experiment with a hydrogen balloon. He measured with three detectors an increase of ionisation up to altitudes of 5 300 m and discovered the extraterrestrial penetrating radiation. The next phase is characterised by W. Kolhörster's confirmation in 1914, doubts by R.A. Millikan and others as well as the spectacular re-discovery of cosmic rays by Millikan in 1926. With the invention of new detectors as the cloud chamber and the Geiger-Müller counter and of the coincidence method the properties of cosmic rays could be investigated. One of the striking results was the discovery that cosmic rays are of corpuscular nature. The broad research activities starting end of the 1920s were the begin of a scientific success story, which nobody of the early protagonists might have imagined. In 1932 C.D. Anderson discovered the antiparticle of the electron. It was the birth of elementary particle physics. Four years later the muon was discovered which was for many years wrongly assumed to be the carrier of the short range nuclear force predicted by H. Yukawa. One of the last high-lights before the particle accelerators took over this field of fundamental research was the discovery of the Yukawa particle. In photographic emulsions exposed by cosmic particles the pion was found in 1947. This

  18. Rapid acceleration leads to rapid weakening in earthquake-like laboratory experiments

    NASA Astrophysics Data System (ADS)

    Chang, J. C.; Lockner, D. A.; Reches, Z.

    2012-12-01

    We simulated the slip of a fault-patch during a large earthquake by rapidly loading an experimental, ring-shaped fault with energy stored in a spinning flywheel. The flywheel abruptly delivers a finite amount of energy by spinning the fault-patch that spontaneously dissipates the energy without operator intervention. We conducted 42 experiments on Sierra White granite (SWG) samples, and 24 experiments on Kasota dolomite (KD) samples. Each experiment starts by spinning a 225 kg disk-shaped flywheel to a prescribed angular velocity. We refer to this experiment as an "earthquake-like slip-event" (ELSE). The strength-evolution in ELSE experiments is similar to the strength-evolution proposed for earthquake models and observed in stick-slip experiments. Further, we found that ELSE experiments are similar to earthquakes in at least three ways: (1) slip driven by the release of a finite amount of stored energy; (2) pattern of fault strength evolution; and (3) seismically observed values, such as average slip, peak-velocity and rise-time. By assuming that the measured slip, D, in ELSE experiments is equivalent to the average slip during an earthquake, we found that ELSE experiments (D = 0.003-4.6 m) correspond to earthquakes in moment-magnitude range of Mw = 4-8. In ELSE experiments, the critical-slip-distance, dc, has mean values of 2.7 cm and 1.2 cm for SWG and KD, that are much shorter than the 1-10 m in steady-state classical experiments in rotary shear systems. We attribute these dc values, to ELSE loading in which the fault-patch is abruptly loaded by impact with a spinning flywheel. Under this loading, the friction-velocity relations are strikingly different from those under steady-state loading on the same rock samples with the same shear system (Reches and Lockner, Nature, 2010). We further note that the slip acceleration in ELSE evolves systematically with fault strength and wear-rate, and that the dynamic weakening is restricted to the period of intense

  19. 14 CFR 121.434 - Operating experience, operating cycles, and consolidation of knowledge and skills.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Operating experience, operating cycles, and... Qualifications § 121.434 Operating experience, operating cycles, and consolidation of knowledge and skills. (a... position, the operating experience, operating cycles, and the line operating flight time for...

  20. Experience from operating germanium detectors in GERDA

    NASA Astrophysics Data System (ADS)

    Palioselitis, Dimitrios; GERDA Collaboration

    2015-05-01

    Phase I of the Germanium Detector Array (GERDA) experiment, searching for the neutrinoless double beta (0νββ) decay of 76Ge, was completed in September 2013. The most competitive half-life lower limit for the 0νββ decay of 76Ge was set (T-0ν1/2 > 2.1 · 1025 yr at 90% C.L.). GERDA operates bare Ge diodes immersed in liquid argon. During Phase I, mainly refurbished semi-coaxial high purity Ge detectors from previous experiments were used. The experience gained with handling and operating bare Ge diodes in liquid argon, as well as the stability and performance of the detectors during GERDA Phase I are presented. Thirty additional new enriched BEGe-type detectors were produced and will be used in Phase II. A subgroup of these detectors has already been used successfully in GERDA Phase I. The present paper gives an overview of the production chain of the new germanium detectors, the steps taken to minimise the exposure to cosmic radiation during manufacturing, and the first results of characterisation measurements in vacuum cryostats.

  1. The General Surgery Chief Resident Operative Experience

    PubMed Central

    Drake, Frederick Thurston; Horvath, Karen D.; Goldin, Adam B.; Gow, Kenneth W.

    2014-01-01

    IMPORTANCE The chief resident (CR) year is a pivotal experience in surgical training. Changes in case volume and diversity may impact the educational quality of this important year. OBJECTIVE To evaluate changes in operative experience for general surgery CRs. DESIGN, SETTING, AND PARTICIPANTS Review of Accreditation Council for Graduate Medical Education case logs from 1989–1990 through 2011–2012 divided into 5 periods. Graduates in period 3 were the last to train with unrestricted work hours; those in period 4 were part of a transition period and trained under both systems; and those in period 5 trained fully under the 80-hour work week. Diversity of cases was assessed based on Accreditation Council for Graduate Medical Education defined categories. MAIN OUTCOMES AND MEASURES Total cases and defined categories were evaluated for changes over time. RESULTS The average total CR case numbers have fallen (271 in period 1 vs 242 in period 5, P < .001). Total CR cases dropped to their lowest following implementation of the 80-hour work week (236 cases), but rebounded in period 5. The percentage of residents’ 5-year operative experience performed as CRs has decreased (30% in period 1 vs 25.6% in period 5, P < .001). Regarding case mix: thoracic, trauma, and vascular cases declined steadily, while alimentary and intra-abdominal operations increased. Recent graduates averaged 80 alimentary and 78 intra-abdominal procedures during their CR years. Compared with period 1, in which these 2 categories represented 47.1% of CR experience, in period 5, they represented 65.2% (P < .001). Endocrine experience has been relatively unchanged. CONCLUSIONS AND RELEVANCE Total CR cases declined especially acutely following implementation of the 80-hour work week but have since rebounded. Chief resident cases contribute less to overall experience, although this proportion stabilized before the 80-hour work week. Case mix has narrowed, with significant increases in alimentary and

  2. Tritium Room Air Monitor Operating Experience Review

    SciTech Connect

    L. C. Cadwallader; B. J. Denny

    2008-09-01

    Monitoring the breathing air in tritium facility rooms for airborne tritium is a radiological safety requirement and a best practice for personnel safety. Besides audible alarms for room evacuation, these monitors often send signals for process shutdown, ventilation isolation, and cleanup system actuation to mitigate releases and prevent tritium spread to the environment. Therefore, these monitors are important not only to personnel safety but also to public safety and environmental protection. This paper presents an operating experience review of tritium monitor performance on demand during small (1 mCi to 1 Ci) operational releases, and intentional airborne inroom tritium release tests. The tritium tests provide monitor operation data to allow calculation of a statistical estimate for the reliability of monitors annunciating in actual tritium gas airborne release situations. The data show a failure to operate rate of 3.5E-06/monitor-hr with an upper bound of 4.7E-06, a failure to alarm on demand rate of 1.4E-02/demand with an upper bound of 4.4E-02, and a spurious alarm rate of 0.1 to 0.2/monitor-yr.

  3. OPERATIONS ELECTRONIC LOGBOOK EXPERIENCE AT BNL.

    SciTech Connect

    SATOGATA,T.; CAMPBELL,I.; MARR,G.; SAMPSON,P.

    2002-06-02

    A web-based system for electronic logbooks, ''elog'', developed at Fermilab (FNAL), has been adopted for use by AGS and RHIC operations and physicists at BNL for the 2001-2 fixed target and collider runs. This paper describes the main functional and technical issues encountered in the first year of electronic logbook use, including security, search and indexing, sequencer integration, archival, and graphics management. We also comment on organizational experience and planned changes for the next facility run starting in September 2002.

  4. Electromagnetic Safety of Spacecraft During Active Experiments with the Use of Plasma Accelerators and Ion Injectors

    NASA Astrophysics Data System (ADS)

    Plokhikh, Andrey; Popov, Garri; Shishkin, Gennady; Antropov, Nikolay; Vazhenin, Nikolay; Soganova, Galina

    Works under the development and application of stationary and pulsed plasma accelerators of charged particles conducted at the Moscow Aviation Institute and Research Institute of Applied Mechanics and Electrodynamics during over 40 years, active experiments on board meteorological rockets, artificial Earth satellites and "Mir" orbital station including [1], allowed to obtain data on the influence of pulsed and continuous plasma injection with the given parameters on the drop of energetic particles out of the radiation belts, efficiency of artificial excitation and propagation of electromagnetic waves in ELF and VLF ranges, and evolution of artificial plasma formations in different regions of ionosphere. Variation of the near-spacecraft electromagnetic environment related to the operation of plasma injectors was registered during active experiments along with the global electrodynamic processes. The measured electromagnetic fields are of rather high intensity and occupy frequency spectrum from some Hz to tens of GHz that may be of definite danger for the operation of spacecraft and its onboard systems. Analysis for the known test data is presented in the paper and methods are discussed for the diagnostics and modeling under laboratory conditions of radiative processes proceeding at the operation of plasma accelerators and ion injectors used while making active space experiments. Great attention is paid to the methodological and metrological bases for making radio measurements in vacuum chambers, design concept and hardware configuration of ground special-purpose instrumentation scientific complexes [2]. Basic requirements are formulated for the measurements and analysis of electromagnetic fields originating during the operation of plasma accelerators, including the radiative induced and conductive components inside the spacecraft, as well as the wave emission and excitation outside the spacecraft, in the ionosphere including. Measurement results for the intrinsic

  5. High-Current Experiments for Accelerator-Based Neutron Capture Therapy Applications

    SciTech Connect

    Gierga, D.P.; Klinkowstein, R.E.; Hughey, B.H.; Shefer, R.E.; Yanch, J.C.; Blackburn, B.W.

    1999-06-06

    Several accelerator-based neutron capture therapy applications are under development. These applications include boron neutron capture therapy for glioblastoma multiform and boron neutron capture synovectomy (BNCS) for rheumatoid arthritis. These modalities use accelerator-based charged-particle reactions to create a suitable neutron source. Neutrons are produced using a high-current, 2-MV terminal tandem accelerator. For these applications to be feasible, high accelerator beam currents must be routinely achievable. An effort was undertaken to explore the operating regime of the accelerator in the milliampere range. In preparation for high-current operation of the accelerator, computer simulations of charged-particle beam optics were performed to establish high-current operating conditions. Herein we describe high beam current simulations and high beam current operation of the accelerator.

  6. Operational plasma density and laser parameters for future colliders based on laser-plasma accelerators

    SciTech Connect

    Schroeder, C. B.; Esarey, E.; Leemans, W. P.

    2012-12-21

    The operational plasma density and laser parameters for future colliders based on laser-plasma accelerators are discussed. Beamstrahlung limits the charge per bunch at low plasma densities. Reduced laser intensity is examined to improve accelerator efficiency in the beamstrahlung-limited regime.

  7. Applied-B ion diode experiments on the Particle Beam Fusion Accelerator-I

    NASA Astrophysics Data System (ADS)

    Dreike, P. L.; Burns, E. J. T.; Slutz, S. A.; Crow, J. T.; Johnson, D. J.; Johnson, P. R.; Leeper, R. J.; Miller, P. A.; Mix, L. P.; Seidel, D. B.; Wenger, D. F.

    1986-08-01

    A series of experiments was performed with an Applied-B ion diode on the Particle Beam Fusion Accelerator-I, with peak voltage, current, and power of approximately 1.8 MV, 6 MA, and 6 TW, respectively. The purpose of these experiments was to explore issues of scaling of Applied-B diode operation from the sub-TW level on single module accelerators to the multi-TW level on a low impedance, self-magnetically insulated, multimodule accelerator. This is an essential step in the development of the 100-TW level light ion beam driver required for inertial confinement fusion. The accelerator and the diode are viewed as a whole because the power pulse delivered by the 36 imperfectly synchronized magnetically insulated transmission lines to the single diode affects module addition, diode operation, and ion beam focusability. We studied electrical coupling between the accelerator and the diode, power flow symmetry, the ionic composition of the beam, and the focusability of the proton component of the beam. Scaling of the diode impedance behavior and beam quality with electrical drive power is obtained from comparison with lower-power experiments. The diode impedance lifetime was about 10 ns, several times shorter than for lower-power experiments. Azimuthal and top-to-bottom variations of the diode and ion currents were found to be approximately ±10%, compared with an estimated requirement of 5%-7% uniformity to avoid focal blurring by self-magnetic field effects. The ion production efficiency was 80%-90%. However, only 50%±10% of the ion current was carried by protons; the balance was carried by multiply charged carbon and oxygen ions. Activation measurements showed a proton beam energy of approximately 50 kJ. A gas cell filled with 5 Torr of argon was used for beam transport. The macroscopic divergence was 15±10 mrad and the microscopic divergence was 20±15 mrad, values that are similar to those from lower-power experiments. A model of beam focusing is formulated that

  8. High Frequency, High Gradient Dielectric Wakefield Acceleration Experiments at SLAC and BNL

    NASA Astrophysics Data System (ADS)

    Rosenzweig, J. B.; Andonian, G.; Muggli, P.; Niknejadi, P.; Travish, G.; Williams, O.; Xuan, K.; Yakimenko, V.

    2010-11-01

    Given the recent success of >GV/m dielectric wakefield accelerator (DWA) breakdown experiments at SLAC, and follow-on coherent Cerenkov radiation (CCR) production at the UCLA Neptune, a UCLA-USC-SLAC collaboration is now implementing a new set of experiments that explore various DWA scenarios. These experiments are motivated by the opportunities presented by the approval of the FACET facility at SLAC, as well as unique pulse-train wakefield drivers at BNL. The SLAC experiments permit further exploration of the multi-GeV/m envelope in DWAs, and will entail investigations of novel materials (e.g. CVD diamond) and geometries (Bragg cylindrical structures, slab-symmetric DWAs), and have an over-riding goal of demonstrating >GeV acceleration in ˜33 cm DWA tubes. In the nearer term before FACET's commissioning, we are performing measurements at the BNL ATF, in which we drive ˜50-200 MV/m fields with single pulses or pulse trains, and observe resonantly driven CCR as well as deflection modes. These experiments are of high relevance to enhancing linear collider DWA designs, as they will demonstrate potential for high efficiency operation with pulse trains, and explore transverse modes for the first time.

  9. High Frequency, High Gradient Dielectric Wakefield Acceleration Experiments at SLAC and BNL

    SciTech Connect

    Rosenzweig, J. B.; Andonian, G.; Niknejadi, P.; Travish, G.; Williams, O.; Xuan, K.; Muggli, P.; Yakimenko, V.

    2010-11-04

    Given the recent success of >GV/m dielectric wakefield accelerator (DWA) breakdown experiments at SLAC, and follow-on coherent Cerenkov radiation (CCR) production at the UCLA Neptune, a UCLA-USC-SLAC collaboration is now implementing a new set of experiments that explore various DWA scenarios. These experiments are motivated by the opportunities presented by the approval of the FACET facility at SLAC, as well as unique pulse-train wakefield drivers at BNL. The SLAC experiments permit further exploration of the multi-GeV/m envelope in DWAs, and will entail investigations of novel materials (e.g. CVD diamond) and geometries (Bragg cylindrical structures, slab-symmetric DWAs), and have an over-riding goal of demonstrating >GeV acceleration in {approx}33 cm DWA tubes. In the nearer term before FACET's commissioning, we are performing measurements at the BNL ATF, in which we drive {approx}50-200 MV/m fields with single pulses or pulse trains, and observe resonantly driven CCR as well as deflection modes. These experiments are of high relevance to enhancing linear collider DWA designs, as they will demonstrate potential for high efficiency operation with pulse trains, and explore transverse modes for the first time.

  10. High Frequency, High Gradient Dielectric Wakefield Acceleration Experiments at SLAC and BNL

    SciTech Connect

    Rosenzweig, James; Travish, Gil; Hogan, Mark; Muggli, Patric; /Southern California U.

    2012-07-05

    Given the recent success of >GV/m dielectric wakefield accelerator (DWA) breakdown experiments at SLAC, and follow-on coherent Cerenkov radiation production at the UCLA Neptune, a UCLA-USC-SLAC collaboration is now implementing a new set of experiments that explore various DWA scenarios. These experiments are motivated by the opportunities presented by the approval of FACET facility at SLAC, as well as unique pulse-train wakefield drivers at BNL. The SLAC experiments permit further exploration of the multi-GeV/m envelope in DWAs, and will entail investigations of novel materials (e.g. CVD diamond) and geometries (Bragg cylindrical structures, slab-symmetric DWAs), and have an over-riding goal of demonstrating >GeV acceleration in {approx}33 cm DWA tubes. In the nearer term before FACET's commissioning, we are planning measurements at the BNL ATF, in which we drive {approx}50-200 MV/m fields with single pulses or pulse trains. These experiments are of high relevance to enhancing linear collider DWA designs, as they will demonstrate potential for efficient operation with pulse trains.

  11. Top-up operation experience at APS.

    SciTech Connect

    Emery, L.

    1999-03-31

    The Advanced Photon Source (APS) is a 7-OeV, third-generation synchrotrons radiation source. To provide more stable beam for users, in September 1998 we began commissioning a new operating mode called ''top-up.'' In this mode, the beam current does not decay but is maintained at a high level using frequent injection, while photon shutters are open and photon beams are delivered to users. The hardware, software, and safety requirements for top-up will be reported. Safety issues related to injection with open photon shutters are covered in companion papers in this conference. Recent operational experience includes testing aspects of top-up injection and delivering beam to X-ray users for a few hours with fractional current stability of 10{sup {minus}3}. We expect to run several top-up operation shifts in Spring 1999. Issues of importance are orbit and emittance transients during the injection and scheduling of injection pulses for the convenience of users.

  12. Coupled operation experience at the Holifield Heavy-Ion research Facility

    SciTech Connect

    Lord, R.S.; Ball, J.B.; Hudson, E.D.; Kloeppel, P.K.; Ludemann, C.A.; Martin, J.A.; Mosko, S.W.; Ziegler, N.F.

    1983-01-01

    The 25URC Pelletron tandem electrostatic accelerator and the Oak Ridge Isochronous Cyclotron (ORIC) comprise the accelerators of the Holifield Heavy-Ion Research Facility (HHIRF). The two machines may be operated individually or coupled, with ORIC serving as an energy booster for the tandem. In the coupled dode, the ion beam enters the cyclotron through the dee stem and is directed by the inflection magnet so that it is tangent to an orbit suitable for acceleration at a higher charge state. A thin carbon foil, placed at the point of tangency, strips the ions so that a substantial fraction are in the desired higher charge state. This fraction of the beam is then accelerated and extracted in the normal fashion. Full energy performance (25 MeV/A oxygen) was demonstrated during first coupled operation in January 1981. Routine coupled operation for experiments commenced in July 1982.

  13. Spring operated accelerator and constant force spring mechanism therefor

    NASA Technical Reports Server (NTRS)

    Shillinger, G. L., Jr. (Inventor)

    1977-01-01

    A spring assembly consisting of an elongate piece of flat spring material formed into a spiral configuration and a free running spool in circumscribing relation to which this spring is disposed was developed. The spring has a distal end that is externally accessible so that when the distal end is drawn along a path, the spring unwinds against a restoring force present in the portion of the spring that resides in a transition region between a relatively straight condition on the path and a fully wound condition on the spool. When the distal end is released, the distal end is accelerated toward the spool by the force existing at the transition region which force is proportional to the cross-sectional area of the spring.

  14. Proof-of-principle experiments of laser Wakefield acceleration

    SciTech Connect

    Nakajima, K.; Kawakubo, T.; Nakanishi, H.

    1994-04-01

    Recently there has been a great interest in laser-plasma accelerators as possible next-generation particle accelerators because of their potential for ultra high accelerating gradients and compact size compared with conventional accelerators. It is known that the laser pulse is capable of exciting a plasma wave propagating at a phase velocity close to the velocity of light by means of beating two-frequency lasers or an ultra short laser pulse. These schemes came to be known as the Beat Wave Accelerator (BWA) for beating lasers or as the Laser Wakefield Accelerator (LWFA) for a short pulse laser. In this paper, the principle of laser wakefield particle acceleration has been tested by the Nd:glass laser system providing a short pulse with a power of 10 TW and a duration of 1 ps. Electrons accelerated up to 18 MeV/c have been observed by injecting 1 MeV/c electrons emitted from a solid target by an intense laser impact. The accelerating field gradient of 30 GeV/m is inferred.

  15. Isentropic compression experiments on the Sandia Z accelerator

    SciTech Connect

    HALL,CLINT A.

    2000-02-21

    A long-standing goal of the equation of state (EOS) community has been the development of a loading capability for direct measurement of material properties along an isentrope. Previous efforts on smooth bore launchers have been somewhat successful, but quite difficult to accurately reproduce, had pressure limitations, or tended to be a series of small shocks as opposed to a smoothly increasing pressure load. A technique has recently been developed on the Sandia National Laboratories Z accelerator which makes use of the high current densities and magnetic fields available to produce nearly isentropic compression of samples that are approximately 1 mm in thickness over approximately 120 ns. Velocity interferometry is used to measure the rear surface motion of these samples. The resulting time resolved velocity profiles from multiple sample thicknesses provide information about mechanical response under isentropic loading conditions and phase transition kinetics. Feasibility experiments have been performed to pressures of approximately 130 kbar in copper and 300 kbar in iron with effects of the {alpha}-{var_epsilon} phase change kinetics in iron clearly observed. Work is in progress to achieve 1--2% accuracy in P-v space along an isentrope, provide uniaxial strain, and to eliminate magnetic field and current diffusion within the sample of interest.

  16. Spallation Neutron Source Operating Experience and Outlook for Upgrades

    NASA Astrophysics Data System (ADS)

    Henderson, Stuart

    2010-03-01

    The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory is a MW-class accelerator-driven pulsed neutron source. The SNS began formal operations in October 2006. Since then, the beam power has been increased to 1 MW, the number of operating hours per year has increased to nearly 5000, the availability has increased to 85%, and the number of operating neutron scattering instruments has increased to 13. Plans are in place to increase the beam power and availability to their design values of 1.4 MW and 90% over the next two years, and to continue the build-out of instruments to 16 by 2012. Two upgrade projects are in the planning stages. In the first, the beam power of the SNS is increased to at least 2 MW by raising the beam energy from 1.0 to 1.3 GeV and the beam current by 60%. In the second, a Second Target Station is constructed, and is powered by sharing beam pulses with the first target station. The operating experience will be described, as will the challenges that have been met along the path toward 1 MW beam power. The strategy for upgrades will also be presented.

  17. The APS booster synchrotron: Commissioning and operational experience

    SciTech Connect

    Milton, S.V.

    1995-07-01

    The Advanced Photon Source (APS) at Argonne National Laboratory (ANL) was constructed to provide a large user community with intense and high brightness synchrotron radiation at x-ray wavelengths. A 7-GeV positron beam is used to generate this light. Acceleration of the beam from 450 MeV to 7 GeV is accomplished at a 2-Hz repetition rate by the booster synchrotron. Commissioning of the booster began in the second quarter of 1994 and continued on into early 1995. The booster is now routinely used to provide beam for the commissioning of the APS storage ring. Reported here are our commissioning and operational experiences with the booster synchrotron.

  18. Operational Experience with the Nb/Pb SRF Photoelectron Gun

    SciTech Connect

    Kamps, T; Barday, R; Jankowiak, A; Knoblock, J; Kugeler, O; Matveenko, A N; Neumann, A; Quast, T; Rudolph, J; Schubert, S G; Volker, J; Kneisel, P; Nietubyc, R; Sekutowicz, J K; Smedley, J; Teichert, J; Volkov, V; Will, I

    2012-07-01

    SRF photoelectron guns offer the promise of high brightness, high average current beam production for the next generation of accelerator driven light sources such as free electron lasers, THz radiation sources or energy-recovery linac driven synchrotron radiation sources. In a first step a fully superconducting RF (SRF) photoelectron gun is under development by a collaboration between HZB, DESY, JLAB, BNL and NCBJ. The aim of the experiment is to understand and improve the performance of a Nb SRF gun cavity coated with a small metallic Pb cathode film on the cavity backplane. This paper describes the highlights from the commissioning and beam parameter measurements. The main focus is on lessons learned from operation of the SRF gun.

  19. The Cngs Facility:. Performance and Operational Experience

    NASA Astrophysics Data System (ADS)

    Gschwendtner, Edda; Cornelis, Karel; Efthymiopoulos, Ilias; Ferrari, Alfredo; Pardons, Ans; Vincke, Heinz; Wenninger, Joerg; Sala, Paola; Guglielmi, Alberto

    2010-04-01

    The CNGS facility (CERN Neutrinos to Gran Sasso) aims at directly detecting muon to tau neutrino oscillations. An intense muon-neutrino beam (1E17 muon neutrinos/day) is generated at CERN and directed over 732 km towards the Gran Sasso National Laboratory, LNGS, in Italy, where two large and complex detectors, OPERA and ICARUS, are located. CNGS is the first long-baseline neutrino facility in which the measurement of the oscillation parameters is performed by observation of tau-neutrino appearance. In this paper, an overview of the CNGS facility is presented. The experience gained in operating this 500 kW neutrino beam facility is described. Major events since the commissioning of the facility in 2006 are summarized. Highlights on CNGS beam performance since the start of physics run in 2008 are given.

  20. Operating experience with a zinc oven

    NASA Astrophysics Data System (ADS)

    Clayburn, Nathan; Brunkow, Evan; Gay, Timothy

    2016-05-01

    A zinc oven has been constructed and tested. Atomic zinc emitted from this resistively heated oven is subsequently excited by a polarized electron beam in crossed-beam geometry. Light emitted in the decay of the (4s5s)3 S1 state to the (4s4p)3 PJ final state, where J = 0, 1, 2, is then detected by a photomultiplier tube for polarization analysis. The zinc oven apparatus and operating experience with the oven are described in detail. Measures to assure that the oven produces a stable, localized beam which does not adhere to essential components of the apparatus are addressed. Estimates of the zinc density are made. The importance of magnetic field control in the apparatus will be discussed. Funded by NSF PHY-1505794.

  1. Operational experience with heavy ions at BNL: An update

    SciTech Connect

    Cardner, C.; Reece, R.K.; Ahrens, L.A.; Barton, D.S.; Beavis, D.; Benjamin, J.; Foelsche, H.; Gill, E.; Raka, E.; Sidhu, S.

    1989-01-01

    Since May 1986, the heavy ion transfer line (HITL) which joins the Tandem Van de Graaff facility and the AGS at Brookhaven National Laboratory has permitted the acceleration of heavy ions (up to sulfur) to 14.5 GeV/nucleon. The Tandem, operating with a pulsed ion source, supplies a fully stripped ion beam at about 7 MeV/nucleon which is transported via the HITL to the AGS. A low frequency rf system accelerates the beam in the AGS to about 200 MeV/nucleon and the high frequency rf system, normally used for proton acceleration, completes the acceleration to 14.5 GeV/nucleon. The high energy ion beams are delivered to four experimental beam lines using standard resonant extraction. Following is an update of the performance and operational characteristics associated with the production, transport, and acceleration of these ion beams. 10 refs., 2 figs., 2 tabs.

  2. Accelerated growth of calcium silicate hydrates: Experiments and simulations

    SciTech Connect

    Nicoleau, Luc

    2011-12-15

    Despite the usefulness of isothermal calorimetry in cement analytics, without any further computations this brings only little information on the nucleation and growth of hydrates. A model originally developed by Garrault et al. is used in this study in order to simulate hydration curves of cement obtained by calorimetry with different known hardening accelerators. The limited basis set of parameters used in this model, having a physical or chemical significance, is valuable for a better understanding of mechanisms underlying in the acceleration of C-S-H precipitation. Alite hydration in presence of four different types of hardening accelerators was investigated. It is evidenced that each accelerator type plays a specific role on one or several growth parameters and that the model may support the development of new accelerators. Those simulations supported by experimental observations enable us to follow the formation of the C-S-H layer around grains and to extract interesting information on its apparent permeability.

  3. Theory of factors limiting high gradient operation of warm accelerating structures

    SciTech Connect

    Nusinovich, Gregory S.; Antonsen, Thomas M.; Kishek, Rami

    2014-07-25

    This final report summarizes the research performed during the time period from 8/1/2010 to 7/31/2013. It consists of two parts describing our studies in two directions: (a) analysis of factors limiting operation of dielectric-loaded accelerating (DLA) structures where the main problem is the occurrence of multipactor on dielectric surfaces, and (b) studies of effects associated with either RF magnetic or RF electric fields which may cause the RF breakdown in high-gradient metallic accelerating structures. In the studies of DLA structures, at least, two accomplishments should be mentioned: the development of a 3D non-stationary, self-consistent code describing the multipactor phenomena and yielding very good agreement with some experimental data obtained in joint ANL/NRL experiments. In the metallic structures, such phenomena as the heating and melting of micro-particles (metallic dust) by RF electric and magnetic fields in single-shot and rep-rate regimes is analyzed. Also, such processes in micro-protrusions on the structure surfaces as heating and melting due to the field emitted current and the Nottingham effect are thoroughly investigated with the account for space charge of emitted current on the field emission from the tip.

  4. SMART-1 operations experience and lessons learnt

    NASA Astrophysics Data System (ADS)

    Camino, Octavio; Alonso, Maria; Gestal, Daniel; de Bruin, Jurriaan; Rathsman, Peter; Kugelberg, Joakim; Bodin, Per; Ricken, Sascha; Blake, Rick; Voss, Pablo Pardo; Stagnaro, Luca

    2007-06-01

    SMART-1 is the first of a series of ESA Small Missions for Advance Research and Technology where elements of the platform and the payload technology have been conceived as a demonstration for future cornerstone missions and an early opportunity for science. SMART-1 has also been an opportunity to experiment with new ways of conducting ground operations taking advantage of both increased satellite autonomy and ground automation tools. The paper will focus on three areas: The accumulated performance of the technology demonstration components since launch as the electrical propulsion engine, the triple-junction solar cells, the lithium-ion batteries, the 32 bit CPU ERC32 Single Chip, the CAN bus, the DTU Star Trackers and the complex on-board autonomy. The changes implemented on-board and on the ground during the lunar phase to increase the data return. The pros and contras in some of the choices made for SMART-1, the developments and solutions implemented to mitigate the problems, the tools developed to automate the operations and the distribution of data.

  5. Operational Radiation Protection in High-Energy Physics Accelerators: Implementation of ALARA in Design and Operation of Accelerators

    SciTech Connect

    Fasso, A.; Rokni, S.; /SLAC

    2011-06-30

    It used to happen often, to us accelerator radiation protection staff, to be asked by a new radiation worker: ?How much dose am I still allowed?? And we smiled looking at the shocked reaction to our answer: ?You are not allowed any dose?. Nowadays, also thanks to improved training programs, this kind of question has become less frequent, but it is still not always easy to convince workers that staying below the exposure limits is not sufficient. After all, radiation is still the only harmful agent for which this is true: for all other risks in everyday life, from road speed limits to concentration of hazardous chemicals in air and water, compliance to regulations is ensured by keeping below a certain value. It appears that a tendency is starting to develop to extend the radiation approach to other pollutants (1), but it will take some time before the new attitude makes it way into national legislations.

  6. The Boeing photocathode accelerator magnetic pulse compression and energy recovery experiment

    SciTech Connect

    Dowell, D.H.; Adamski, J.L.; Hayward, T.D.

    1995-12-31

    An 18 MeV, photocathode accelerator operating at 433 MHz is being commissioned for FEL applications. The accelerator consists of a two-cell RF photocathode imjector followed by four new multicell cavities. The two cell injector has previously been operated at a micropulse repetition frequency of 27 MHz, a micropulse charge of 5 nC and 25% duty factor.

  7. GPU acceleration experience with RRTMG long wave radiation model

    NASA Astrophysics Data System (ADS)

    Price, Erik; Mielikainen, Jarno; Huang, Bormin; Huang, HungLung A.; Lee, Tsengdar

    2013-10-01

    in many weather forecast and climate models. RRTMG_LW is in operational use in ECMWF weather forecast system, the NCEP global forecast system, the ECHAM5 climate model, Community Earth System Model (CESM) and the weather and forecasting (WRF) model. RRTMG_LW has also been evaluated for use in GFDL climate model. In this paper, we examine the feasibility of using graphics processing units (GPUs) to accelerate the RRTMG_LW as used by the WRF. GPUs can provide a substantial improvement in RRTMG speed by supporting the parallel computation of large numbers of independent radiative calculations. Furthermore, using commodity GPUs for accelerating RRTMG_LW allows getting a much higher computational performance at lower price point than traditional CPUs. Furthermore, power and cooling costs are significantly reduced by using GPUs. A GPU-compatible version of RRTMG was implemented and thorough testing was performed to ensure that the original level of accuracy is retained. Our results show that GPUs can provide significant speedup over conventional CPUs. In particular, Nvidia's GTX 680 GPU card can provide a speedup of 69x for the compared to its single-threaded Fortran counterpart running on Intel Xeon E5-2603 CPU.

  8. Utilization of operating experience to prevent piping failures at steam plants

    SciTech Connect

    Adams, T.S.; Dietrich, E.B.

    1999-11-01

    The key to preventing flow-accelerated corrosion (FAC) induced piping failures in steam plants is the development and implementation of a methodical program for assessing plant susceptibility to FAC and managing the effects of FAC. One of the key elements of an effective FAC program is the accurate and comprehensive utilization of plant-specific and industry-wide operating experience. Operating experience should be used to develop the program to identify specific areas for inspection or replacement, and to maintain an effective program. This paper discusses the utilization of operating experience in FAC programs at nuclear power plants, fossil plants and other steam plants.

  9. An approach to accelerate iterative methods for solving nonlinear operator equations

    NASA Astrophysics Data System (ADS)

    Nedzhibov, Gyurhan H.

    2011-12-01

    We propose and analyze a generalization of a Steffensen type acceleration method in case of extracting a locally unique solution of a nonlinear operator equation on a Banach space. In order, we use a special choice of a divided difference for operators. Convergence analysis and some applications of the obtained results are provided.

  10. Medical supply on contingency military operations: experience from Operation GRITROCK.

    PubMed

    Robinson, J P; Reeves, P

    2015-01-01

    Medical supply during military operations has the ability to affect the efficacy of the operation being undertaken, either negatively or positively. An appropriately-managed maritime platform with a robust medical supply chain during transit and on arrival in theatre is the main aim. A secure supply chain will reduce any implications that logistics may have with regard to capability, and negate the effects of deficiencies of short shelf life items occurring over time and during use in high tempo operations. PMID:26867409

  11. Synthetic Vision Systems - Operational Considerations Simulation Experiment

    NASA Technical Reports Server (NTRS)

    Kramer, Lynda J.; Williams, Steven P.; Bailey, Randall E.; Glaab, Louis J.

    2007-01-01

    Synthetic vision is a computer-generated image of the external scene topography that is generated from aircraft attitude, high-precision navigation information, and data of the terrain, obstacles, cultural features, and other required flight information. A synthetic vision system (SVS) enhances this basic functionality with real-time integrity to ensure the validity of the databases, perform obstacle detection and independent navigation accuracy verification, and provide traffic surveillance. Over the last five years, NASA and its industry partners have developed and deployed SVS technologies for commercial, business, and general aviation aircraft which have been shown to provide significant improvements in terrain awareness and reductions in the potential for Controlled-Flight-Into-Terrain incidents/accidents compared to current generation cockpit technologies. It has been hypothesized that SVS displays can greatly improve the safety and operational flexibility of flight in Instrument Meteorological Conditions (IMC) to a level comparable to clear-day Visual Meteorological Conditions (VMC), regardless of actual weather conditions or time of day. An experiment was conducted to evaluate SVS and SVS-related technologies as well as the influence of where the information is provided to the pilot (e.g., on a Head-Up or Head-Down Display) for consideration in defining landing minima based upon aircraft and airport equipage. The "operational considerations" evaluated under this effort included reduced visibility, decision altitudes, and airport equipage requirements, such as approach lighting systems, for SVS-equipped aircraft. Subjective results from the present study suggest that synthetic vision imagery on both head-up and head-down displays may offer benefits in situation awareness; workload; and approach and landing performance in the visibility levels, approach lighting systems, and decision altitudes tested.

  12. Synthetic vision systems: operational considerations simulation experiment

    NASA Astrophysics Data System (ADS)

    Kramer, Lynda J.; Williams, Steven P.; Bailey, Randall E.; Glaab, Louis J.

    2007-04-01

    Synthetic vision is a computer-generated image of the external scene topography that is generated from aircraft attitude, high-precision navigation information, and data of the terrain, obstacles, cultural features, and other required flight information. A synthetic vision system (SVS) enhances this basic functionality with real-time integrity to ensure the validity of the databases, perform obstacle detection and independent navigation accuracy verification, and provide traffic surveillance. Over the last five years, NASA and its industry partners have developed and deployed SVS technologies for commercial, business, and general aviation aircraft which have been shown to provide significant improvements in terrain awareness and reductions in the potential for Controlled-Flight-Into-Terrain incidents / accidents compared to current generation cockpit technologies. It has been hypothesized that SVS displays can greatly improve the safety and operational flexibility of flight in Instrument Meteorological Conditions (IMC) to a level comparable to clear-day Visual Meteorological Conditions (VMC), regardless of actual weather conditions or time of day. An experiment was conducted to evaluate SVS and SVS-related technologies as well as the influence of where the information is provided to the pilot (e.g., on a Head-Up or Head-Down Display) for consideration in defining landing minima based upon aircraft and airport equipage. The "operational considerations" evaluated under this effort included reduced visibility, decision altitudes, and airport equipage requirements, such as approach lighting systems, for SVS-equipped aircraft. Subjective results from the present study suggest that synthetic vision imagery on both head-up and head-down displays may offer benefits in situation awareness; workload; and approach and landing performance in the visibility levels, approach lighting systems, and decision altitudes tested.

  13. Experience and Operational Improvements, Mixer Pump Performance

    SciTech Connect

    Erian, Fadel F.; Mullen, O Dennis; Kellogg, Michael I.

    2002-03-20

    Millions of gallons of radioactive waste are stored in large underground tanks at DOE sites. The waste is made up of settled solids, in sludge form, at the bottom of the tank and a layer of supernatant liquid on top of it. It is necessary to mix the solids in the sludge layer with the supernatant liquid to facilitate their removal from the storage tanks for remediation. Our goal is to improve the mobilization of the settled solids by optimizing mixing with the supernatant liquid and preserving the mobility of the solids. This report investigates whether time-phase separation between pump head oscillations affects overall sludge mobilization. If a mixing jet from one pump happens to follow temporarily the path of the lead mixing jet, it may be possible to prevent or slow down the resettling of the heavy solid particles, maintaining them in suspension. If a retrieval pump were operating at the same time, it could facilitate removal of such particles. Preliminary experiments were carried out to observe whether time-phase separation has some influence on the overall mobilization. A brief account is presented of the successful mobilization and removal of most of the radioactive waste from Tank D8-2 at the West Valley Demonstration Project using time-phase separation techniques.

  14. Operant acceleration during a pre-reward stimulus1

    PubMed Central

    Henton, Wendon W.; Brady, Joseph V.

    1970-01-01

    Stimuli of 20, 40, and 80 sec duration terminated with five non-response-contingent food pellets were superimposed upon lever pressing reinforced with single pellets on a DRL 30-sec schedule. Two rhesus monkeys served as subjects. No change in response frequency was observed during the 20- and 40-sec stimuli. During the 80-sec pre-food stimulus, overall response frequency increased to approximately 150% and 220% of pre-stimulus levels, and the temporal distributions of interresponse times shifted toward the shorter intervals. When the 80-sec stimulus was no longer terminated with food, the response frequency decreased and the temporal distributions of interresponse times gradually approached pre-stimulus levels. An increased frequency of short interresponse times and an increase in response rate was again observed when the pellet termination procedure was reinstituted with the 80-sec stimulus. No change in response frequency or interresponse times was observed in the absence of the conditioning stimulus, and performance efficiency, as reflected in the ratio of responses to reinforcements during non-stimulus periods, remained stable throughout the experiment. PMID:16811437

  15. AWAKE, The Advanced Proton Driven Plasma Wakefield Acceleration Experiment at CERN

    NASA Astrophysics Data System (ADS)

    Gschwendtner, E.; Adli, E.; Amorim, L.; Apsimon, R.; Assmann, R.; Bachmann, A.-M.; Batsch, F.; Bauche, J.; Berglyd Olsen, V. K.; Bernardini, M.; Bingham, R.; Biskup, B.; Bohl, T.; Bracco, C.; Burrows, P. N.; Burt, G.; Buttenschön, B.; Butterworth, A.; Caldwell, A.; Cascella, M.; Chevallay, E.; Cipiccia, S.; Damerau, H.; Deacon, L.; Dirksen, P.; Doebert, S.; Dorda, U.; Farmer, J.; Fedosseev, V.; Feldbaumer, E.; Fiorito, R.; Fonseca, R.; Friebel, F.; Gorn, A. A.; Grulke, O.; Hansen, J.; Hessler, C.; Hofle, W.; Holloway, J.; Hüther, M.; Jaroszynski, D.; Jensen, L.; Jolly, S.; Joulaei, A.; Kasim, M.; Keeble, F.; Li, Y.; Liu, S.; Lopes, N.; Lotov, K. V.; Mandry, S.; Martorelli, R.; Martyanov, M.; Mazzoni, S.; Mete, O.; Minakov, V. A.; Mitchell, J.; Moody, J.; Muggli, P.; Najmudin, Z.; Norreys, P.; Öz, E.; Pardons, A.; Pepitone, K.; Petrenko, A.; Plyushchev, G.; Pukhov, A.; Rieger, K.; Ruhl, H.; Salveter, F.; Savard, N.; Schmidt, J.; Seryi, A.; Shaposhnikova, E.; Sheng, Z. M.; Sherwood, P.; Silva, L.; Soby, L.; Sosedkin, A. P.; Spitsyn, R. I.; Trines, R.; Tuev, P. V.; Turner, M.; Verzilov, V.; Vieira, J.; Vincke, H.; Wei, Y.; Welsch, C. P.; Wing, M.; Xia, G.; Zhang, H.

    2016-09-01

    The Advanced Proton Driven Plasma Wakefield Acceleration Experiment (AWAKE) aims at studying plasma wakefield generation and electron acceleration driven by proton bunches. It is a proof-of-principle R&D experiment at CERN and the world's first proton driven plasma wakefield acceleration experiment. The AWAKE experiment will be installed in the former CNGS facility and uses the 400 GeV/c proton beam bunches from the SPS. The first experiments will focus on the self-modulation instability of the long (rms ~12 cm) proton bunch in the plasma. These experiments are planned for the end of 2016. Later, in 2017/2018, low energy (~15 MeV) electrons will be externally injected into the sample wakefields and be accelerated beyond 1 GeV. The main goals of the experiment will be summarized. A summary of the AWAKE design and construction status will be presented.

  16. Physical processes at work in sub-30 fs, PW laser pulse-driven plasma accelerators: Towards GeV electron acceleration experiments at CILEX facility

    NASA Astrophysics Data System (ADS)

    Beck, A.; Kalmykov, S. Y.; Davoine, X.; Lifschitz, A.; Shadwick, B. A.; Malka, V.; Specka, A.

    2014-03-01

    Optimal regimes and physical processes at work are identified for the first round of laser wakefield acceleration experiments proposed at a future CILEX facility. The Apollon-10P CILEX laser, delivering fully compressed, near-PW-power pulses of sub-25 fs duration, is well suited for driving electron density wakes in the blowout regime in cm-length gas targets. Early destruction of the pulse (partly due to energy depletion) prevents electrons from reaching dephasing, limiting the energy gain to about 3 GeV. However, the optimal operating regimes, found with reduced and full three-dimensional particle-in-cell simulations, show high energy efficiency, with about 10% of incident pulse energy transferred to 3 GeV electron bunches with sub-5% energy spread, half-nC charge, and absolutely no low-energy background. This optimal acceleration occurs in 2 cm length plasmas of electron density below 1018 cm-3. Due to their high charge and low phase space volume, these multi-GeV bunches are tailor-made for staged acceleration planned in the framework of the CILEX project. The hallmarks of the optimal regime are electron self-injection at the early stage of laser pulse propagation, stable self-guiding of the pulse through the entire acceleration process, and no need for an external plasma channel. With the initial focal spot closely matched for the nonlinear self-guiding, the laser pulse stabilizes transversely within two Rayleigh lengths, preventing subsequent evolution of the accelerating bucket. This dynamics prevents continuous self-injection of background electrons, preserving low phase space volume of the bunch through the plasma. Near the end of propagation, an optical shock builds up in the pulse tail. This neither disrupts pulse propagation nor produces any noticeable low-energy background in the electron spectra, which is in striking contrast with most of existing GeV-scale acceleration experiments.

  17. USA/FBR program status FFTF operations startup experience

    SciTech Connect

    Moffitt, W.C.; Izatt, R.D.

    1981-06-01

    This paper gives highlights of the major Operations evaluations and operational results of the startup acceptance testing program and initiation of normal operating cycles for experiment irradiation in the FFTF. 33 figures. (DLC)

  18. High power operational experience with the LANSCE Linac

    SciTech Connect

    Rybarcyk, Lawrence J

    2008-01-01

    The heart of the Los Alamos Neutron Science Center (LANSCE) is a pulsed linear accelerator that is used to simultaneously provide H+ and H- beams to several user facilities. This accelerator contains two Cockcroft-Walton style injectors, a 100-MeV drift tube linac and an 800-MeV coupled cavity linac. This presentation will touch on various aspects of the high power operation including performance, tune-up strategy, beam losses and machine protection.

  19. Analysis of Acceleration, Airspeed, and Gust-Velocity Data From a Four-Engine Transport Airplane Operating Over a Northwestern United States Alaska Route

    NASA Technical Reports Server (NTRS)

    Engel, Jerome N.; Copp, Martin R.

    1959-01-01

    Acceleration, airspeed, and altitude data obtained with an NACA VGH recorder from a four-engine commercial transport airplane operating over a northwestern United States-Alaska route were evaluated to determine the magnitude and frequency of occurrence of gust and maneuver accelerations., operating airspeeds, and gust velocities. The results obtained were then compared with the results previously reported in NACA Technical Note 3475 for two similar airplanes operating over transcontinental routes in the United States. No large variations in the gust experience for the three operations were noted. The results indicate that the gust-load experience of the present operation closely approximated that of the central transcontinental route in the United States with which it is compared and showed differences of about 4 to 1 when compared with that of the southern transcontinental route in the United States. In general, accelerations due to gusts occurred much more frequently than those due to operational maneuvers. At a measured normal-acceleration increment of 0.5g, accelerations due to gusts occurred roughly 35 times more frequently than those due to operational maneuvers.

  20. Enabling cost-effective high-current burst-mode operation in superconducting accelerators

    DOE PAGESBeta

    Sheffield, Richard L.

    2015-06-01

    Superconducting (SC) accelerators are very efficient for CW or long-pulse operation, and normal conducting (NC) accelerators are cost effective for short-pulse operation. The addition of a short NC linac section to a SC linac can correct for the energy droop that occurs when pulsed high-current operation is required that exceeds the capability of the klystrons to replenish the cavity RF fields due to the long field fill-times of SC structures, or a requirement to support a broad range of beam currents results in variable beam loading. This paper describes the implementation of this technique to enable microseconds of high beam-current,more » 90 mA or more, in a 12 GeV SC long-pulse accelerator designed for the MaRIE 42-keV XFEL proposed for Los Alamos National Laboratory.« less

  1. Enabling cost-effective high-current burst-mode operation in superconducting accelerators

    SciTech Connect

    Sheffield, Richard L.

    2015-06-01

    Superconducting (SC) accelerators are very efficient for CW or long-pulse operation, and normal conducting (NC) accelerators are cost effective for short-pulse operation. The addition of a short NC linac section to a SC linac can correct for the energy droop that occurs when pulsed high-current operation is required that exceeds the capability of the klystrons to replenish the cavity RF fields due to the long field fill-times of SC structures, or a requirement to support a broad range of beam currents results in variable beam loading. This paper describes the implementation of this technique to enable microseconds of high beam-current, 90 mA or more, in a 12 GeV SC long-pulse accelerator designed for the MaRIE 42-keV XFEL proposed for Los Alamos National Laboratory.

  2. Acceleration units for the Induction Linac Systems Experiment (ILSE)

    SciTech Connect

    Faltens, A.; Brady, V.; Brodzik, D.; Hansen, L.; Laslett, L.J.; Mukherjee, S.; Bubp, D.; Ravenscroft, D.; Reginato, L.

    1989-03-01

    The design of a high current heavy ion induction linac driver for inertial confinement fusion is optimized by adjusting the acceleration units along the length of the accelerator to match the beam current, energy, and pulse duration at any location. At the low energy end of the machine the optimum is a large number of electrostatically focused parallel beamlets, whereas at higher energies the optimum is a smaller number of magnetically focused beams. ILSE parallels this strategy by using 16 electrostatically focused beamlets at the low end followed by 4 magnetically focused beams after beam combining. 3 refs., 2 figs.

  3. Defense waste processing facility radioactive operations. Part 1 - operating experience

    SciTech Connect

    Little, D.B.; Gee, J.T.; Barnes, W.M.

    1997-12-31

    The Savannah River Site`s Defense Waste Processing Facility (DWPF) near Aiken, SC is the nation`s first and the world`s largest vitrification facility. Following a ten year construction program and a 3 year non-radioactive test program, DWPF began radioactive operations in March 1996. This paper presents the results of the first 9 months of radioactive operations. Topics include: operations of the remote processing equipment reliability, and decontamination facilities for the remote processing equipment. Key equipment discussed includes process pumps, telerobotic manipulators, infrared camera, Holledge{trademark} level gauges and in-cell (remote) cranes. Information is presented regarding equipment at the conclusion of the DWPF test program it also discussed, with special emphasis on agitator blades and cooling/heating coil wear. 3 refs., 4 figs.

  4. Two-Channel Rectangular Dielectric Wake Field Accelerator Structure Experiment

    SciTech Connect

    Sotnikov, G. V.; Marshall, T. C.; Shchelkunov, S. V.; Didenko, A.; Hirshfield, J. L.

    2009-01-22

    A design is presented for a two-channel 30-GHz rectangular dielectric wake field accelerator structure being built for experimental tests at Argonne National Laboratory (ANL). This structure allows for a transformer ratio T much greater than two, and permits continuous coupling of energy from drive bunches to accelerated bunches. It consists of three planar slabs of cordierite ceramic ({epsilon} = 4.7) supported within a rectangular copper block, forming a drive channel 12 mmx6 mm, and an accelerator channel 2 mmx6 mm. When driven by a 50 nC, 14 MeV single bunch available at ANL, theory predicts an acceleration field of 6 MeV/m, and T = 12.6. Inherent transverse wake forces introduce deflections and some distortion of bunch profiles during transit through the structure that are estimated to be tolerable. Additionally, a cylindrical two-channel DWFA is introduced which shares many advantages of the rectangular structure including high T, and the added virtue of axisymmetry that eliminates lowest-order transverse deflecting forces.

  5. Present and future high-energy accelerators for neutrino experiments

    SciTech Connect

    Kourbanis, I.; /Fermilab

    2007-06-01

    There is an active neutrino program making use of the high-energy (larger than 50 GeV) accelerators both in USA at Fermilab with NuMI and at CERN in Europe with CNGS. In this paper we will review the prospects for high intensity high energy beams in those two locations during the next decade.

  6. Mini acceleration and deceleration driving strategy to increase the operational time of flywheel hybrid module

    NASA Astrophysics Data System (ADS)

    Manaf, Muhammad Zaidan Abdul; Fakeruddin, Shafarul Hafidi; Zakaria, Mohamad Shukri; Saadun, Mohd Noor Asril; Hanafi, Mohd Hafidzal Mohd

    2015-05-01

    This paper presents a new driving strategy to increase the operational time of flywheel hybrid module. The flywheel hybrid module contains low cost mechanical parts which installed on the small motorcycle. Based on normal driving cycles characteristics, the Mini-AD driving strategy is develop. It is involved a series of short or mini acceleration cycle and short deceleration cycle on top of the normal driving cycles. The new strategy is simulated for flywheel hybrid module, aimed for acceleration phase only. Simulations show that the new driving strategy can increase the operational time of flywheel hybrid module up to 62.5%.

  7. Space acceleration measurement system description and operations on the First Spacelab Life Sciences Mission

    NASA Technical Reports Server (NTRS)

    Delombard, Richard; Finley, Brian D.

    1991-01-01

    The Space Acceleration Measurement System (SAMS) project and flight units are briefly described. The SAMS operations during the STS-40 mission are summarized, and a preliminary look at some of the acceleration data from that mission are provided. The background and rationale for the SAMS project is described to better illustrate its goals. The functions and capabilities of each SAMS flight unit are first explained, then the STS-40 mission, the SAMS's function for that mission, and the preparation of the SAMS are described. Observations about the SAMS operations during the first SAMS mission are then discussed. Some sample data are presented illustrating several aspects of the mission's microgravity environment.

  8. Evaluation of commercial ADC radiation tolerance for accelerator experiments

    DOE PAGESBeta

    Chen, K.; Chen, H.; Kierstead, J.; Takai, H.; Rescia, S.; Hu, X.; Xu, H.; Mead, J.; Lanni, F.; Minelli, M.

    2015-08-17

    Electronic components used in high energy physics experiments are subjected to a radiation background composed of high energy hadrons, mesons and photons. These particles can induce permanent and transient effects that affect the normal device operation. Ionizing dose and displacement damage can cause chronic damage which disable the device permanently. Transient effects or single event effects are in general recoverable with time intervals that depend on the nature of the failure. The magnitude of these effects is technology dependent with feature size being one of the key parameters. Analog to digital converters are components that are frequently used in detectormore » front end electronics, generally placed as close as possible to the sensing elements to maximize signal fidelity. We report on radiation effects tests conducted on 17 commercially available analog to digital converters and extensive single event effect measurements on specific twelve and fourteen bit ADCs that presented high tolerance to ionizing dose. We discuss mitigation strategies for single event effects (SEE) for their use in the large hadron collider environment.« less

  9. Evaluation of commercial ADC radiation tolerance for accelerator experiments

    SciTech Connect

    Chen, K.; Chen, H.; Kierstead, J.; Takai, H.; Rescia, S.; Hu, X.; Xu, H.; Mead, J.; Lanni, F.; Minelli, M.

    2015-08-17

    Electronic components used in high energy physics experiments are subjected to a radiation background composed of high energy hadrons, mesons and photons. These particles can induce permanent and transient effects that affect the normal device operation. Ionizing dose and displacement damage can cause chronic damage which disable the device permanently. Transient effects or single event effects are in general recoverable with time intervals that depend on the nature of the failure. The magnitude of these effects is technology dependent with feature size being one of the key parameters. Analog to digital converters are components that are frequently used in detector front end electronics, generally placed as close as possible to the sensing elements to maximize signal fidelity. We report on radiation effects tests conducted on 17 commercially available analog to digital converters and extensive single event effect measurements on specific twelve and fourteen bit ADCs that presented high tolerance to ionizing dose. We discuss mitigation strategies for single event effects (SEE) for their use in the large hadron collider environment.

  10. Evaluation of commercial ADC radiation tolerance for accelerator experiments

    NASA Astrophysics Data System (ADS)

    Chen, K.; Chen, H.; Kierstead, J.; Takai, H.; Rescia, S.; Hu, X.; Xu, H.; Mead, J.; Lanni, F.; Minelli, M.

    2015-08-01

    Electronic components used in high energy physics experiments are subjected to a radiation background composed of high energy hadrons, mesons and photons. These particles can induce permanent and transient effects that affect the normal device operation. Ionizing dose and displacement damage can cause chronic damage which disable the device permanently. Transient effects or single event effects are in general recoverable with time intervals that depend on the nature of the failure. The magnitude of these effects is technology dependent with feature size being one of the key parameters. Analog to digital converters are components that are frequently used in detector front end electronics, generally placed as close as possible to the sensing elements to maximize signal fidelity. We report on the development of a technique for testing analog to digital converters for radiation effects, in particular for single event effects. A total of seventeen commercial ADCs were evaluated for ionizing dose tolerance and extensive SEU measurements performed on a twelve and fourteen bit ADCs. Mitigation strategies for single event effects (SEE) are discussed for their use in the large hadron collider environment.

  11. Variable frequency heavy-ion linac, RILAC I. Design, construction and operation of its accelerating structure

    NASA Astrophysics Data System (ADS)

    Odera, Masatoshi; Chiba, Yoshiaki; Tonuma, Tadao; Hemmi, Masatake; Miyazawa, Yoshitoshi; Inoue, Toshihiko; Kambara, Tadashi; Kase, Masayuki; Kubo, Toshiyuki; Yoshida, Fusako

    1984-11-01

    A variable frequency linear accelerator at RIKEN (IPCR), which is named RILAC, is designed to accelerate ions of almost every element in the periodic table. In this report, the design, construction and performance of the resonator cavities of this linac are described. A new accelerating structure was developed for the variable frequency scheme. The principal aim of the development was to obtain a configuration within the cavity to keep a uniform voltage distribution along the accelerating axis over the wide range of resonant frequencies required. The final form adopted is a coaxial quarter-wave type resonator with a race-track-like cross section for its coaxial inner and outer conductors. It has a movable shorting device as a frequency tuner and its open end is enlarged and loaded with drift tubes, connected to the inner and outer conductors alternatingly. The structure can maintain the required uniformity of the accelerating voltage within 10% in spite of resonant frequency tuning between 17 and 45 MHz. A relatively modest accelerating gradient was chosen so that cw operation could be realized. The RILAC is composed of six such cavities which are independently excited and it succeeded in the acceleration of a beam through all the cavities in 1981.

  12. Real-Time Data from the Orbital Acceleration Research Experiment (OARE)

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The objective of the Orbital Acceleration Research Experiment (OARE) is to measure, with high accuracy, the low-frequency, low-magnitude acceleration levels onboard the space shuttle. The shuttle experiences acceleration from atmospheric drag, gravity gradient forces, shuttle rotations, crew activities, water/waste dumps, and shuttle attitude thrusters. The OARE instrument has successfully flown on five past shuttle missions and is scheduled for five upcoming microgravity science missions. The data collected by OARE will be utilized by microgravity scientists to better predict and analyze the influence and effects of the shuttle's on-orbit microgravity environment on experiments in materials, combustion, and fluids research.

  13. The 7-gap-resonator-accelerator for the REX-ISOLDE-experiment at CERN

    NASA Astrophysics Data System (ADS)

    Podlech, H.; Grieser, M.; von Hahn, R.; Papureanu, S.; Repnow, R.; Schwalm, D.

    1998-04-01

    The Radioactive Beam Experiment at ISOLDE (REX-ISOLDE-Experiment) which presently is being developed and under construction at CERN serves to investigate exotic, very neutron rich, radioactive nuclei [1](Radioactive beam EXperiment at ISOLDE: Coloumb Excitation and Neutron Transfer Reactions of Exotic Nuclei, Proposal to the ISOLDE commitee, CERNSIC94-25). A linear accelerator delivers radioactive ions which are produced by the isotope separator ISOLDE with energies between 0.85 and 2.2 MeV/u. The Linac will consist of a RFQ-accelerator, an interdigital H-Structure (IH) and three 7-gap-resonators with variable energy. While the LMU Munich is responsible for the frontpart of the accelerator, the backpart is being built by the MPI [2](H. Podlech, Master Thesis, MPI-H-V21-1997, Heidelburg, 1997). After estimation of the voltage of one resonator to 1.75 MV at 90 kW, the design velocities were fixed to 5.4%, 6.0% and 6.6% of the velocity of light. Three downscaled models (1:2.5) were built in order to optimize the shuntimpedance and the field-distribution at the operation frequency of the amplifiers of 101.28 MHz. The optimization of all low power resonators is now successfully finished. Extensive beam dynamic calculations were made in order to optimize the transmission of the beam up to the target. It turned out that final energies between 0.85 and 2.2 MeV/u with nearly 100% transmission can be achieved. The acceptance in the x-plane is 1.2π mm mrad (norm.) and in the y-plane 3.0π mm mrad (norm.). The bunchlength of the fully accelerated beam (2.2 MeV/u) is 2.4 ns at the target. The development of the resonators was accompanied by extensive MAFIA calculations. It could be demonstrated that spiral-resonators like 7-gap-resonators can be calculated with MAFIA with an accuracy of 1% in comparison with experimental results. Presently, the tanks and the half shells of the power type resonators are manufactured in the workshops of the MPI.

  14. Accelerating the commercialization on new technologies. [free market operation of federal alternate energy sources programs

    NASA Technical Reports Server (NTRS)

    Kuehn, T. J.; Nawrocki, P. M.

    1978-01-01

    It is suggested that federal programs for hastening the adoption of alternative energy sources must operate within the free market structure. Five phases of the free market commercialization process are described. Federal role possibilities include information dissemination and funding to stimulate private sector activities within these five phases, and federally sponsored procedures for accelerating commercialization of solar thermal small power systems are considered.

  15. Mod-2 wind turbine field operations experiment

    NASA Technical Reports Server (NTRS)

    Gordon, L. H.

    1985-01-01

    The three-machine, 7.5 MW Goodnoe Hills located near Goldendale, Washington and is now in a research/experimental operations phase that offers a unique opportunity to study the effects of single and multiple wind turbines interacting with each other, the power grid; and the environment. Following a brief description of the turbine and project history, this paper addresses major problem areas and research and development test results. Field operations, both routine and nonroutine, are discussed. Routine operation to date has produced over 13,379,000 KWh of electrical energy during 11,064 hr of rotation. Nonroutine operation includes suspended activities caused by a crack in the low speed shaft that necessitated a redesign and reinstallation of this assembly on all three turbines. With the world's largest cluster back in full operation, two of the turbines will be operated over the next years to determine their value as energy producer. The third unit will be used primarily for conducting research tests requiring configuration changes to better understand the wind turbine technology. Technical areas summarized pertain to system performance and enhancements. Specific research tests relating to acoustics, TV interference, and wake effects conclude the paper.

  16. Orbiter Kapton wire operational requirements and experience

    NASA Technical Reports Server (NTRS)

    Peterson, R. V.

    1994-01-01

    The agenda of this presentation includes the Orbiter wire selection requirements, the Orbiter wire usage, fabrication and test requirements, typical wiring installations, Kapton wire experience, NASA Kapton wire testing, summary, and backup data.

  17. Experience in using FlexCtrl SCADA for accelerator automation

    NASA Astrophysics Data System (ADS)

    Nikiforov, A.; Aleinikov, V.; Sychev, A.; Borina, I.; Rukavishnikov, A.

    2012-07-01

    The programmed component of the automatic control of accelerators on the basis of licensed software packages (FlexCtrl SCADA, Photon Application Builder, and Cogent DataHub) and an additionally developed library of classes (related to visual programming with regard to functional capabilities and which all together represent an integrated media for producing the automation system) is described in the article. The number of features of the media components and the number of the components themselves can be increased since the developed media is characterized as open.

  18. Second-order state estimation experiments using acceleration measurements

    NASA Technical Reports Server (NTRS)

    Belvin, W. K.

    1992-01-01

    The estimation of dynamic states for feedback control of structural systems using second-order differential equations and acceleration measurements is described. The formulation of the observer model, and the design of the observer gains is discussed in detail. It is shown the second-order observer is highly stable because the stability constraints on the observer gains are model independent. The limitation of the proposed observer is the need for 'nearly' collocated actuators and accelerometers. Experimental results using a control-structure interaction testbed are presented that show the second-order observer provided more stability than a Kalman filter estimator without decreasing closed-loop performance.

  19. Field Operations Program Chevrolet S-10 (Lead-Acid) Accelerated Reliability Testing - Final Report

    SciTech Connect

    J. Francfort; J. Argueta; M. Wehrey; D. Karner; L. Tyree

    1999-07-01

    This report summarizes the Accelerated Reliability testing of five lead-acid battery-equipped Chevrolet S-10 electric vehicles by the US Department of Energy's Field Operations Program and the Program's testing partners, Electric Transportation Applications (ETA) and Southern California Edison (SCE). ETA and SCE operated the S-10s with the goal of placing 25,000 miles on each vehicle within 1 year, providing an accelerated life-cycle analysis. The testing was performed according to established and published test procedures. The S-10s' average ranges were highest during summer months; changes in ambient temperature from night to day and from season-to-season impacted range by as much as 10 miles. Drivers also noted that excessive use of power during acceleration also had a dramatic effect on vehicle range. The spirited performance of the S-10s created a great temptation to inexperienced electric vehicle drivers to ''have a good time'' and to fully utilize the S-10's acceleration capability. The price of injudicious use of power is greatly reduced range and a long-term reduction in battery life. The range using full-power accelerations followed by rapid deceleration in city driving has been 20 miles or less.

  20. a New Mobile Electron Accelerator for Intra Operative Electron Radiation Therapy

    NASA Astrophysics Data System (ADS)

    Adrich, P.; Baczewski, A.; Baran, M.; Drabik, W.; Gryn, K.; Hanke, R.; Jakubowska, E.; Jankowski, E.; Kędzierski, G.; Kielar, N.; Kujawiński, Ł.; Kopeć, J.; Kosiński, K.; Kozioł, R.; Kraszewski, P.; Krawczyk, P.; Kulczycka, E.; Lalik, P.; Marczenko, M.; Masternak, A.; Misiarz, A.; Olszewski, J.; Ozon, K.; Pławski, E.; Polak, A.; Psonka, W.; Rutkowska, M.; Rzadkiewicz, J.; Sienkiewicz, Z.; Staszczak, M.; Swat, K.; Syntfeld-Każuch, A.; Terka, M.; Wasilewski, A.; Wilczek, J.; Wojciechowski, M.; Wójtowicz, M.; Wronka, S.; Wysocka-Rabin, A.; Zalewski, K.

    2014-02-01

    A demonstrator of a new, highly mobile, robotized linear electron accelerator for Intra Operative Electron Radiation Therapy (IOERT) is under construction at National Centre for Nuclear Studies. In an IOERT treatment, a high dose of electron radiation is delivered in a single fraction directly to an exposed location after tumor ablation during oncological surgery. Due to the fact that the tumor can be located anywhere in the body, a high maneuverability of the accelerator and its adaptability to anatomical conditions are required. Moreover, since the treatment is usually executed in an unshielded operation room, the radiation protection issues are of principal importance. To assure safety of the patient and medical personnel, the therapeutic head is designed to constrain the radiation to the volume of the tumor lodge while minimizing leakage and stray radiation. For these reasons, construction of accelerators for IOERT differs considerably from the construction of linear electron accelerators for external beam radiation therapy. This paper presents some challenges and solutions in construction of the accelerator and in particular its therapeutic head with beam forming system.

  1. Recent advances in software for beamline design, accelerator operations and personnel training

    NASA Astrophysics Data System (ADS)

    Gillespie, George H.; Hill, Barrey W.; Martono, Hendy; Moore, John M.

    2000-03-01

    Accelerators are finding new applications in research, industry, medicine, as well as other fields, and there is a growing need for new tools to improve the productivity of scientists and engineers involved with these emerging accelerator applications. Several advances in computer software have been made that focus on meeting those needs. This paper summarizes recent work in the development of a unique software framework designed specifically to support the accelerator community: the Multi-Platform Shell for Particle Accelerator Related Codes (SPARC MP). SPARC MP includes a sophisticated beamline object model, an extensive library of GUI components, and supports a variety of particle optics codes and add-on tools. This framework has been used to create the Particle Beam Optics Laboratory (PBO Lab TM) family of software applications. PBO Lab has been used for beamline design, as a computer aid for teaching particle optics, and to support accelerator operations. Several popular charged particle optics programs, including MARYLIE, TRANSPORT, TURTLE and TRACE 3-D, have been integrated with a new version of PBO Lab. The modeling and simulation capabilities of these codes allow PBO Lab to support a wide spectrum of accelerator types. New external data interface tools are available to import beamline parameters from other sources, for example, to utilize magnet strengths generated by a control system. An overview of the new version of PBO Lab is presented.

  2. Acceleration of Dense Flowing Plasmas using ICRF Power in the VASIMR Experiment

    SciTech Connect

    Squire, Jared P.

    2005-09-26

    ICRF power in the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) concept energizes ions (> 100 eV) in a diverging magnetic field to accelerate a dense ({approx} 1019 m-3) flowing plasma to velocities useful for space propulsion ({approx}100 km/s). Theory predicts that an ICRF slow wave launched from the high field side of the resonance will propagate in the magnetic beach to absorb nearly all of the power at the resonance, thus efficiently converting the RF power to ion kinetic energy. The plasma flows through the resonance only once, so the ions are accelerated in a single pass. This process has proven efficient ({approx} 70%) with an ICRF power level of 1.5 kW at about 3.6 MHz in the VASIMR experiment, VX-30, using deuterium plasma created by a helicon operating in flowing mode. We have measured ICRF plasma loading up to 2 ohms, consistent with computational predictions made using Oak Ridge National Laboratory's EMIR code. Recent helicon power upgrades (20 kW at 13.56 MHz) have enabled a 5 cm diameter target plasma for ICRF with an ion flux of over 3x10 20 s-1 and a high degree of ionization. This paper summarizes our ICRF results and presents the latest helicon developments in VX-30.

  3. High Availability On-line Relational Databases for Accelerator Control and Operation

    SciTech Connect

    Dohan,D.; Dalesio, L.; Carcassi, G.

    2009-05-04

    The role that relational database (RDB) technology plays in accelerator control and operation continues to grow in such areas as electronic logbooks, machine parameter definitions, and facility infrastructure management. RDBs are increasingly relied upon to provide the official 'master' copy of these data. Whereas the services provided by the RDB have traditionally not been 'mission critical', the availability of modern RDB management systems is now equivalent to that of standard computer file-systems. RDBs can be relied on to supply pseudo real-time response to operator and machine physicist requests. This paper describes recent developments in the IRMIS RDB project. Generic lattice support has been added, serving as the driver for model-based machine control. Abstract physics name service and process variable introspection has been added. Specific emphasis has been placed both on providing fast response time to accelerator operators and modeling code requests, as well as high (24/7) availability of the RDB service.

  4. FFTF operating experience, 1982-1984

    SciTech Connect

    Waldo, J B; Franz, G R; Loika, E F; Krupar, J J

    1984-01-01

    The Fast Flux Test Facility (FFTF) is a 400 Mwt sodium-cooled fast reactor operating at the Hanford Engineering Development Laboratory, Richland, Washington, to conduct fuels and materials testing in support of the US Liquid Metal Fast Breeder Reactor (LMFBR) program. Startup and initial power testing included a comprehensive series of nonnuclear and nuclear tests to verify the thermal, hydraulic, and neutronic characteristics of the plant. A specially designed series of natural circulation tests were then performed to demonstrate the inherent safety features of the plant. Early in 1982, the FFTF began its first 100-day irradiation cycle. Since that time the plant has operated very well, achieving a cycle capacity factor of 94% in the most recent irradiation cycle. Seventy-five specific test assemblies and 25,000 individual fuel pins have been irradiated, some in excess of 80 MWd/Kg.

  5. Weapons Experiments Division Explosives Operations Overview

    SciTech Connect

    Laintz, Kenneth E.

    2012-06-19

    Presentation covers WX Division programmatic operations with a focus on JOWOG-9 interests. A brief look at DARHT is followed by a high level overview of explosives research activities currently being conducted within in the experimental groups of WX-Division. Presentation covers more emphasis of activities and facilities at TA-9 as these efforts have been more traditionally aligned with ongoing collaborative explosive exchanges covered under JOWOG-9.

  6. Laser wakefield acceleration experiments at the University of Michigan

    SciTech Connect

    Matsuoka, T.; McGuffey, C.; Horovitz, Y.; Dollar, F.; Bulanov, S. S.; Chvykov, V.; Kalintchenko, G.; Reed, S.; Rousseau, P.; Yanovsky, V.; Maksimchuk, A.; Krushelnick, K.; Huntington, C. M.; Drake, R. P.; Levin, M.; Zigler, A.

    2009-01-22

    Laser wakefield acceleration (LWFA) in a supersonic gas-jet using a self-guided laser pulse was studied by changing the laser power and electron density. The recently upgraded HERCULES laser facility equipped with wavefront correction enables a peak intensity of 8x10{sup 19} W/cm{sup 2} at laser power of 100 TW to be delivered to the gas-jet using f/10 focusing optics. We found that electron beam charge was increased significantly with an increase of the laser power from 30 TW to 80 TW and showed density threshold behavior at a fixed laser power. Betatron motion of electrons was also observed depending on laser power and electron density.

  7. Accelerator Challenges and Opportunities for Future Neutrino Experiments

    SciTech Connect

    Zisman, Michael S

    2010-12-24

    There are three types of future neutrino facilities currently under study, one based on decays of stored beta-unstable ion beams (?Beta Beams?), one based on decays of stored muon beams (?Neutrino Factory?), and one based on the decays of an intense pion beam (?Superbeam?). In this paper we discuss the challenges each design team must face and the R&D being carried out to turn those challenges into technical opportunities. A new program, the Muon Accelerator Program, has begun in the U.S. to carry out the R&D for muon-based facilities, including both the Neutrino Factory and, as its ultimate goal, a Muon Collider. The goals of this program will be briefly described.

  8. NASA's Spitzer Space Telescope's operational mission experience

    NASA Astrophysics Data System (ADS)

    Wilson, Robert K.; Scott, Charles P.

    2006-06-01

    Spitzer Space Telescope, the fourth and final of NASA's Great Observatories, and the cornerstone to NASA's Origins Program, launched on 25 August 2003 into an Earth-trailing solar orbit to acquire infrared observations from space. Spitzer has an 85cm diameter beryllium telescope, which operates near absolute zero utilizing a liquid helium cryostat for cooling the telescope. The helium cryostat though designed for a 2.5 year lifetime, through creative usage now has an expected lifetime of 5.5 years. Spitzer has completed its in-orbit checkout/science verification phases and the first two years of nominal operations becoming the first mission to execute astronomical observations from a solar orbit. Spitzer was designed to probe and explore the universe in the infrared utilizing three state of the art detector arrays providing imaging, photometry, and spectroscopy over the 3-160 micron wavelength range. Spitzer is achieving major advances in the study of astrophysical phenomena across the expanses of our universe. Many technology areas critical to future infrared missions have been successfully demonstrated by Spitzer. These demonstrated technologies include lightweight cryogenic optics, sensitive detector arrays, and a high performance thermal system, combining radiation both passive and active cryogenic cooling of the telescope in space following its warm launch. This paper provides an overview of the Spitzer mission, telescope, cryostat, instruments, spacecraft, its orbit, operations and project management approach and related lessons learned.

  9. A call for virtual experiments: accelerating the scientific process.

    PubMed

    Cooper, Jonathan; Vik, Jon Olav; Waltemath, Dagmar

    2015-01-01

    Experimentation is fundamental to the scientific method, whether for exploration, description or explanation. We argue that promoting the reuse of virtual experiments (the in silico analogues of wet-lab or field experiments) would vastly improve the usefulness and relevance of computational models, encouraging critical scrutiny of models and serving as a common language between modellers and experimentalists. We review the benefits of reusable virtual experiments: in specifying, assaying, and comparing the behavioural repertoires of models; as prerequisites for reproducible research; to guide model reuse and composition; and for quality assurance in the translational application of models. A key step towards achieving this is that models and experimental protocols should be represented separately, but annotated so as to facilitate the linking of models to experiments and data. Lastly, we outline how the rigorous, streamlined confrontation between experimental datasets and candidate models would enable a "continuous integration" of biological knowledge, transforming our approach to systems biology. PMID:25433232

  10. Participation in the definition, conduct, and analysis of particle accelerator experiments for the first Spacelab Mission

    NASA Technical Reports Server (NTRS)

    Burch, J. L.

    1994-01-01

    The Space Experiments with Particle Accelerators (SEPAC) is a joint endeavor between NASA and the Institute of Space and Aeronautical Sciences (ISAS) in Japan. Its objectives are to use energetic electron beams to investigate beam-atmosphere interactions and beam-plasma interactions in the earth's upper atmosphere and ionosphere using the shuttle Spacelab. Two flights of SEPAC have occurred to date (Spacelab 1 on STS-9 in Nov.-Dec. 1983 and ATLAS 1 on STS-45 in Mar.-Apr. 1992). The SEPAC instrumentation is available for future missions, and the scientific results of the first two missions justify further investigations; however, at present there are no identifiable future flight opportunities. As specified in the contract, the primary purpose of this report is to review the scientific accomplishments of the ATLAS 1 SEPAC experiments, which have been documented in the published literature, with only a brief review of the earlier Spacelab 1 results. One of the main results of the Spacelab 1 SEPAC experiments was that the ejection of plasma from the magnetoplasmadynamic (MPD) arcjet was effective in maintaining vehicle charge neutralization during electron beam firings, but only for a brief period of 10 ms or so. Therefore, a xenon plasma contactor, which can provide continuous vehicle charge neutralization, was developed for the ATLAS 1 SEPAC experiments. Because of the successful operation of the plasma contactor on ATLAS 1, it was possible to perform experiments on beam-plasma interactions and beam-atmosphere interactions at the highest beam power levels of SEPAC. In addition, the ability of the plasma contactor to eject neutral xenon led to a successful experiment on the critical ionization velocity (CIV) phenomena on ATLAS 1.

  11. Experience in operating the Bratsk Reservoir

    SciTech Connect

    Nazarov, A.V.

    1984-04-01

    The Bratsk reservoir is the largest in the USSR and second largest in the world. Initially, the reservoir was expected to be filled by the end of 1966. However, the actual filling was not completed until September of 1967. During filling and in the first years of operation it was constantly necessary to deal with floating timber in order to ensure normal operation of the hydrostation, navigation safety, conditions for fishery, and fulfillment of the sanitary requirements. During seasonal variations of the reservoir level about 160 sq km of the shore zone was subjected to variable flooding and waterlogging. Maximum erosion occurred on expanded stretches, and within their limits on slopes composed of loam and sand deposits. Within the narrows, where the banks are composed mainly of hard and soft rocks and wave action is weak, erosion is negligible. Wind setup and setdown cause maximum denivellation of the water surface. The maximum increase of the level during setup reaches 232 cm and the maximum decrease during setdown is 24 cm. Seiche oscillations with various amplitudes and periods are observed on the reservoir surface. The main uses of the complex are hydropower, water transport, timber floating, water supply, and fishery. For the successful development of the shores of reservoirs it is necessary to select the construction sites with consideration of possible occurrence of karstic and landslide processes; the construction of heavy structures requires special karst-control measures. 3 references, 3 figures, 1 table.

  12. Physics study of the TRADE : TRIGA accelerator driven experiment.

    SciTech Connect

    Naberejnev, D.; Imel, G.; Palmiotti, G.; Salvatores, M.

    2004-01-13

    This report deals with the validation of an ADS dynamic behavior through the TRADE program. We first describe the motivations behind the TRADE project. This includes the types of ADS experiments to be performed and their necessity, beam trips issues, representativity of the experiment, and steps to be taken in the validation procedure. Then we perform the characterization of the TRADE core using deterministic methods. The general core description is given. A number of results related to the core criticality and modeling with different geometries are presented. Finally we report the experimental results of the recent critical measurements including the control rod calibration, determination of the critical configurations and fluxes in the core.

  13. Flight experiments to improve terminal area operations

    NASA Technical Reports Server (NTRS)

    Salmirs, S.; Morello, S. A.

    1978-01-01

    A brief description is given of the objectives and activities of the terminal configured vehicle (TCV) program and of some of the airborne facilities. A short analysis of some particular problems in CTOL operations in the terminal area is also presented to show how the program's technical objectives are related to the defined problems. The test aircraft was flown both manually and automatically with manual monitoring over paths including 130 deg intercepts and 2.0 km and 0.8 km finals. Some statistical data are presented from these and other flight profiles designed to address specific terminal area problems. An overview is presented of research studies receiving emphasis in the next biennium and their application to the terminal area. A description of work undertaken to study the addition of adjacent traffic information to present map displays is also given.

  14. Flight experiments to improve terminal area operations

    NASA Technical Reports Server (NTRS)

    Salmirs, S.; Morello, S. A.

    1978-01-01

    A brief description is given of the objectives and activities of the terminal configured vehicle (TCV) program and of some of the airborne facilities. A short analysis of some particular problems of CTOL operations in the terminal area is also presented to show how the program's technical objectives are related to the defined problems. The test aircraft was flown both manually and automatically with manual monitoring over paths including 130 deg intercepts and 2.0 km (1.1. n. mi.) and 0.8 km (0.44 n. mi.) finals. Some statistical data are presented from these and other flight profiles designed to address specific terminal in the next biennium and their application to the terminal area. A description of work being undertaken to study the addition of adjacent traffic information to present map displays is also given.

  15. Subjective Acceleration of Time Experience in Everyday Life across Adulthood

    ERIC Educational Resources Information Center

    John, Dennis; Lang, Frieder R.

    2015-01-01

    Most people believe that time seems to pass more quickly as they age. Building on assumptions of socioemotional selectivity theory, we investigated whether awareness that one's future lifetime is limited is associated with one's experience of time during everyday activities across adulthood in 3 studies. In the first 2 studies (Study 1: N = 608;…

  16. Operating experience, economics and wind plant optimization

    SciTech Connect

    Poulsen, E.V.

    1995-09-01

    The Vestas group has installed more than 4,500 wind turbines (640 MW) world-wide. Experience from this development contradicts several myths about the costs of producing wind energy. The paper will document that it Vestas wind projects: (1) wind turbine availability does not decrease with age; (2) service and maintenance costs do not increase with age; (3) that initial investment costs have decreased dramatically over the last ten years. The relative importance of different project costs are discussed, and sensitivity analysis is performed to illustrate that O and M costs, wind turbine availability, and financing parameters significantly influence the cost of energy production. New Vestas turbine models are introduced, including V42-600 kW and V60-1500 kW turbines.

  17. New half-voltage and double phase operation of the Hermes III linear induction accelerator

    SciTech Connect

    Mikkelson, K.A.; Westfall, R.L.; Harper-Slaboszewicz, V.J. ); Neely, S.M. )

    1991-01-01

    The standard operating mode produces bremsstrahlung with an endpoint energy of about 18 MeV. This paper describes a new mode with a 8.5 MeV endpoint energy and the same standard mode pulse characteristics achieved by operating only half of the accelerator at full charge with the advantage of minimal setup time. An extension of the new half-voltage mode is to use the other half of the accelerator for delivering a second pulse at a later time with the same technique. The double pulse mode is ideal for beam generation which requires a long interpulse time in the millisecond regime. The beam characteristics of the two half-voltage pulses are nearly identical with the nominal radiation pulse full width at half maximum of 21 ns and 10--90 risetime of 11 ns recorded by the same Compton diode radiation monitors on instruments triggered 30 ms apart.

  18. The safe, economical operation of a slightly subcritical reactor and transmutor with a small proton accelerator

    SciTech Connect

    Takahashi, Hiroshi

    1994-04-01

    This report describes methods in which an accelerator can be used to increase the safety and neutron economy of a power reactor and transmutor of long-lived radioactive wastes, such as minor actinides and fission products, by providing neutrons for its subcritical operation. Instead of the rather large subcriticality of k=0.9--0.95 which we originally proposed for such a transmutor, we propose to use a slightly subcritical reactor, such as k=0.99, which will avoid many of the technical difficulties that are associated with large subcriticality, such as localized power peaking, radiation damage due to the injection of medium-energy protons, the high current accelerator, and the requirement for a long beam-expansion section. We analyzed the power drop that occurred in Phoenix reactor, and show that the operating this reactor in subcritical condition improves its safety.

  19. Operating Experience Review of the INL HTE Gas Monitoring System

    SciTech Connect

    L. C. Cadwallader; K. G. DeWall

    2010-06-01

    This paper describes the operations of several types of gas monitors in use at the Idaho National Laboratory (INL) High Temperature Electrolysis Experiment (HTE) laboratory. The gases monitored at hydrogen, carbon monoxide, carbon dioxide, and oxygen. The operating time, calibration, and unwanted alarms are described. The calibration session time durations are described. Some simple statistics are given for the reliability of these monitors and the results are compared to operating experiences of other types of monitors.

  20. SPALLATION NEUTRON SOURCE OPERATIONAL EXPERIENCE AT 1 MW

    SciTech Connect

    Galambos, John D

    2011-01-01

    The Spallation Neutron Source (SNS) has been operating at the MW level for about one year. Experience in beam loss control and machine activation at this power level is presented. Also experience with machine protection systems is reviewed, which is critical at this power level. One of the most challenging operational aspects of high power operation has been attaining high availability, which is also discussed

  1. Kaonic atoms measurements at the DAFNE accelerator: the SIDDHARTA experiment

    NASA Astrophysics Data System (ADS)

    Rizzo, A.; Bazzi, M.; Beer, G.; Berucci, C.; Bombelli, L.; Bragadireanu, A. M.; Cargnelli, M.; Curceanu (Petrascu, C.; Corradi, G.; dUffizi, A.; Fiorini, C.; Frizzi, T.; Ghio, F.; Guaraldo, C.; Hayano, R. S.; Iliescu, M.; Ishiwatari, T.; Iwasaki, M.; Kienle, P.; Levi Sandri, P.; Longoni, A.; Lucherini, V.; Marton, J.; Okada, S.; Pietreanu, D.; Ponta, T.; Romero Vidal, A.; Sbardella, E.; Scordo, A.; Shi, H.; Sirghi, D. L.; Sirghi, F.; Tatsuno, H.; Tudorache, A.; Tudorache, V.; Vazquez Doce, O.; Widmann, E.; Wunschek, B.; Zmeskal, J.

    2012-03-01

    Kaonic Hydrogen and Helium X-ray measurements play nowadays a fundamental role in testing the reliability of the Chiral Perturbation Theory as a realisation of the Quantum Chromodynamics at low energies. Dictated by both electromagnetic and strong interaction, X-ray transitions at lower energy levels of these complex bound systems offer indeed the unique opportunity to perform a threshold measurements of zero-energy meson-nucleon scattering. Nowadays the SIDDHARTA experiment at DAFNE collider is the only apparatus which can provide such kind of measurements with the high precision needed to disentangle different theoretical calculation scenarios. In this work we present the SIDDHARTA experiment performances and results, with a focus on the main topics of light kaonic atom physics.

  2. Recycling galvanized steel: Operating experience and benefits

    SciTech Connect

    Dudek, F.J.; Daniels, E.J.; Morgan, W.A.

    1993-08-01

    In response to the increase in consumption of galvanized steel for automobiles in the last decade and the problems associated with remelting larger quantities of galvanized steel scrap, a process is being developed to separate and recover the steel and zinc from galvanized ferrous scrap. The zinc is dissolved from the scrap in hot caustic using anodic assistance and is recovered electrolytically as dendritic powder. The dezinced ferrous scrap is rinsed and used directly. The process is effective for zinc, lead, and aluminum removal on loose and baled scrap and on all types of galvanized steel. The process has been pilot tested for batch treatment of 900 tonnes of mostly baled scrap. A pilot plant to continuously treat loose scrap, with a design capacity of 48,000 tonnes annually, has been in operation in East Chicago, Indiana since early in 1993. The first 450 t of scrap degalvanized in the pilot plant have residual zinc below 0.01% and sodium dragout below 0.01%. Use of degalvanized steel scrap decreases raw materials, environmental compliance, and opportunity costs to steel- and iron-makers. Availability of clean degalvanized scrap may enable integrated steel producers to recycle furnace dusts to the sinter plant and EAF shops to produce flat products without use of high quality scrap alternatives such as DRI, pig iron, or iron carbide. Recycling the components of galvanized steel scrap saves primary energy, decreases zinc imports, and adds value to the scrap. The quantities of zinc available by the year 2000 from prompt and obsolete automotive scrap win approach 25% of zinc consumed in the major automotive production centers of the world. Zinc recycling from galvanized steel scrap, either before or after scrap melting, will have to be implemented.

  3. Space radiation accelerator experiments - The role of neutrons and light ions

    NASA Astrophysics Data System (ADS)

    Norbury, John W.; Slaba, Tony C.

    2014-10-01

    The importance of neutrons and light ions is considered when astronauts spend considerable time in thickly shielded regions of a spacecraft. This may be relevant for space missions both in and beyond low Earth orbit (LEO). In addition to heavy ion experiments at accelerators, it is suggested that an increased emphasis on experiments with lighter ions may be useful in reducing biological uncertainties.

  4. Acceleration ground test program to verify GAS payload No. 559 structure/support avionics and experiment structural integrity

    NASA Technical Reports Server (NTRS)

    Cassanto, John M.; Cassanto, Valerie A.

    1988-01-01

    Acceleration ground tests were conducted on the Get Away Special (GAS) payload 559 to verify the structural integrity of the structure/support avionics and two of the planned three flight experiments. The ITA (Integrated Test Area) Standardized Experiment Module (ISEM) structure was modified to accommodate the experiments for payload 559. The ISEM avionics consisted of a heavy duty sliver zinc power supply, three orthogonal-mounted low range microgravity accelerometers, a tri-axis high range accelerometer, a solid state recorder/programmer sequencer, and pressure and temperature sensors. The tests were conducted using the Gravitational Plant Physiology Laboratory Centrifuge of the University City Science Center in Philadelphia, PA. The launch-powered flight steady state acceleration profile of the shuttle was simulated from lift-off through jettison of the External Tank (3.0 g's). Additional tests were conducted at twice the nominal powered flight acceleration levels (6 g's) and an over-test condition of four times the powered flight loads to 12.6 g's. The present test program has demonstrated the value of conducting ground tests to verify GAS payload experiment integrity and operation before flying on the shuttle.

  5. 3D Simulations for a Micron-Scale, Dielectric-Based Acceleration Experiment

    SciTech Connect

    Yoder, R. B.; Travish, G.; Xu Jin; Rosenzweig, J. B.

    2009-01-22

    An experimental program to demonstrate a dielectric, slab-symmetric accelerator structure has been underway for the past two years. These resonant devices are driven by a side-coupled 800-nm laser and can be configured to maintain the field profile necessary for synchronous acceleration and focusing of relativistic or nonrelativistic particles. We present 3D simulations of various versions of the structure geometry, including a metal-walled structure relevant to ongoing cold tests on resonant properties, and an all-dielectric structure to be constructed for a proof-of-principle acceleration experiment.

  6. The LILIA experiment: Energy selection and post-acceleration of laser generated protons

    NASA Astrophysics Data System (ADS)

    Turchetti, Giorgio; Sinigardi, Stefano; Londrillo, Pasquale; Rossi, Francesco; Sumini, Marco; Giove, Dario; De Martinis, Carlo

    2012-12-01

    The LILIA experiment is planned at the SPARCLAB facility of the Frascati INFN laboratories. We have simulated the laser acceleration of protons, the transport and energy selection with collimators and a pulsed solenoid and the post-acceleration with a compact high field linac. For the highest achievable intensity corresponding to a = 30 over 108 protons at 30 MeV with a 3% spread are selected, and at least107 protons are post-accelerated up to 60 MeV. If a 10 Hz repetition rated can be achieved the delivered dose would be suitable for the treatment of small superficial tumors.

  7. The LILIA experiment: Energy selection and post-acceleration of laser generated protons

    SciTech Connect

    Turchetti, Giorgio; Sinigardi, Stefano; Londrillo, Pasquale; Rossi, Francesco; Sumini, Marco; Giove, Dario; De Martinis, Carlo

    2012-12-21

    The LILIA experiment is planned at the SPARCLAB facility of the Frascati INFN laboratories. We have simulated the laser acceleration of protons, the transport and energy selection with collimators and a pulsed solenoid and the post-acceleration with a compact high field linac. For the highest achievable intensity corresponding to a= 30 over 10{sup 8} protons at 30 MeV with a 3% spread are selected, and at least10{sup 7} protons are post-accelerated up to 60 MeV. If a 10 Hz repetition rated can be achieved the delivered dose would be suitable for the treatment of small superficial tumors.

  8. Physical conditions for conducting radiobiological experiments in beams of accelerated particles with high linear energy transfer

    NASA Technical Reports Server (NTRS)

    Kudryashov, Y. I.; Marennyy, A. M.; Popov, V. I.; Aykhorn, K.; Ertsgreber, G.

    1974-01-01

    The design and construction of an accelerator to conduct radiobiological experiments is reported that uses aluminum filters to control the accelerated ion beam while preserving its stability, and a vacuum chamber to conduct the ion beam with the help of a collector through a lavsan exit port to the target. Depth distribution of the absorbed dose from a monodirectional ion beam is practically completely represented by the change in the energy spectrum of the biological object.

  9. TSTA Piping and Flame Arrestor Operating Experience Data

    SciTech Connect

    Cadwallader, Lee C.; Willms, R. Scott

    2014-10-01

    The Tritium Systems Test Assembly (TSTA) was a facility dedicated to tritium handling technology and experiment research at the Los Alamos National Laboratory. The facility operated from 1984 to 2001, running a prototype fusion fuel processing loop with ~100 grams of tritium as well as small experiments. There have been several operating experience reports written on this facility’s operation and maintenance experience. This paper describes analysis of two additional components from TSTA, small diameter gas piping that handled small amounts of tritium in a nitrogen carrier gas, and the flame arrestor used in this piping system. The operating experiences and the component failure rates for these components are discussed in this paper. Comparison data from other applications are also presented.

  10. Simulations of an acceleration scheme for producing high intensity and low emittance antiproton beam for Fermilab collider operation

    SciTech Connect

    Wu, Vincent; Bhat, C.M.; MacLachlan, J.A.; /Fermilab

    2005-05-01

    During Fermilab collider operation, the Main Injector (MI) provides high intensity and low emittance proton and antiproton beams for the Tevatron. The present coalescing scheme for antiprotons in the Main Injector yields about a factor of two increase in the longitudinal emittance and a factor of 5% to 20% decrease in intensity before injection to the Tevatron. In order to maximize the integrated luminosity delivered to the collider experiments, it is important to minimize the emittance growth and maximize the intensity of the MI beam. To this end, a new scheme using a combination of 2.5 MHz and 53 MHz accelerations has been developed and tested. This paper describes the full simulation of the new acceleration scheme, taking account of space charge, 2.5 MHz and 53 MHz beam loading, and the effect of residual 53 MHz rf voltage during 2.5 MHz acceleration and rf manipulations. The simulations show the longitudinal emittance growth at the 10% level with no beam loss. The experimental test of the new scheme is reported in another PAC05 paper.

  11. Femtosecond Operation of the LCLS for User Experiments

    SciTech Connect

    Frisch, Josef; Bostedt, Christoph; Bozek, John; Brachmann, Axel; Coffee, Ryan; Decker, Franz-Josef; Ding, Yuantao; Dowell, David; Emma, Paul; Gilevich, Sasha; Haller, Gunther; Hays, Gregory; Hering, Philippe; Hill, Bruce; Huang, Zhirong; Iverson, Richard Kanter, Elliot; Kraessig, Bertold; Loos, Henrik; Miahnahri, Alan; Nuhn, Heinz-Dieter; /SLAC /SLAC /SLAC /SLAC /SLAC /SLAC /SLAC /SLAC /SLAC /SLAC /SLAC /LBL, Berkeley

    2010-09-02

    In addition to its normal operation at 250pC, the LCLS has operated with 20pC bunches delivering X-ray beams to users with energies between 800eV and 2 keV and with bunch lengths below 10 fs FWHM. A bunch arrival time monitor and timing transmission system provide users with sub 50 fs synchronization between a laser and the X-rays for pump/probe experiments. We describe the performance and operational experience of the LCLS for short bunch experiments.

  12. Terminal-area STOL operating systems experiments program

    NASA Technical Reports Server (NTRS)

    Smith, D. W.; Watson, D.; Christensen, J. V.

    1973-01-01

    Information which will aid in the choice by the U.S. Government and industry of system concepts, design criteria, operating procedures for STOL aircraft and STOL ports, STOL landing guidance systems, air traffic control systems, and airborne avionics and flight control systems. Ames has developed a terminal-area STOL operating systems experiments program which is a part of the joint DOT/NASA effort is discussed. The Ames operating systems experiments program, its objectives, the program approach, the program schedule, typical experiments, the research facilities to be used, and the program status are described.

  13. A self-injection acceleration test experiment for the FLAME laser

    NASA Astrophysics Data System (ADS)

    Labate, L.; Anelli, F.; Bacci, A.; Batani, D.; Bellaveglia, M.; Benedetti, C.; Benocci, R.; Cacciotti, L.; Cecchetti, C. A.; Ciricosta, O.; Clozza, A.; Cultrera, L.; Di Pirro, G.; Drenska, N.; Faccini, R.; Ferrario, M.; Filippetto, D.; Gallo, S.; Fioravanti, S.; Gamucci, A.; Gatti, G.; Ghigo, A.; Giulietti, A.; Giulietti, D.; Köster, P.; Levato, T.; Lollo, V.; Pace, E.; Pathak, N.; Rossi, A.; Serafini, L.; Turchetti, G.; Vaccarezza, C.; Valente, P.; Vicario, C.; Gizzi, L. A.

    2010-10-01

    A 250-TW laser system (FLAME - Frascati laser for acceleration and multidisciplinary experiments) is now in its commissioning phase in a new laboratory at LNF-INFN in the framework of the PLASMONX (Plasma acceleration and monochromatic X-ray generation) project. The laser will deliver<25 fs duration pulses with an energy up to 6 J, at a 10 Hz repetition rate. An ad hoc target area has also been designed and is currently being set up, allowing the first test experiments of electron laser wakefield acceleration to be carried out over the next few months in a safe, radiation-protected environment. An overview of the main features of the laser system and target area is given, along with a survey of the design and set-up of the self-injection test experiment, which is expected to reach the production of sub-GeV electron bunches.

  14. Shielding Benchmark Experiments Through Concrete and Iron with High-Energy Proton and Heavy Ion Accelerators

    NASA Astrophysics Data System (ADS)

    Nakamura, T.; Sasaki, M.; Nunomiya, T.; Nakao, N.; Kim, E.; Kurosawa, T.; Taniguchi, S.; Iwase, H.; Uwamino, Y.; Shibata, T.; Ito, S.; Fukumura, A.; Perry, D. R.; Wright, P.

    The deep penetration of neutrons through thick shield has become a very serious problem in the shielding design of high-energy, high-intensity accelerator facility. In the design calculation, the Monte Carlo transport calculation through thick shields has large statistical errors and the basic nuclear data and model used in the existing Monte Carlo codes are not well evaluated because of very few experimental data. It is therefore strongly needed to do the deep penetration experiment as shielding benchmark for investigating the calculation accuracy. Under this circumference, we performed the following two shielding experiments through concrete and iron, one with a 800 MeV proton accelerator of the Rutherford Appleton Laboratory (RAL), England and the other with a high energy heavy iron accelerator of the National Institute of Radiological Sciences (NIRS), Japan. Here these two shielding benchmark experiments are outlined.

  15. Operating Experience Review of Tritium-in-Water Monitors

    SciTech Connect

    S. A. Bruyere; L. C. Cadwallader

    2011-09-01

    Monitoring tritium facility and fusion experiment effluent streams is an environmental safety requirement. This paper presents data on the operating experience of a solid scintillant monitor for tritium in effluent water. Operating experiences were used to calculate an average monitor failure rate of 4E-05/hour for failure to function. Maintenance experiences were examined to find the active repair time for this type of monitor, which varied from 22 minutes for filter replacement to 11 days of downtime while waiting for spare parts to arrive on site. These data support planning for monitor use; the number of monitors needed, allocating technician time for maintenance, inventories of spare parts, and other issues.

  16. The safe and economical operations of a reactor driven by a small proton accelerator

    SciTech Connect

    Takahashi, Hiroshi; Takashita, Hirofumi

    1994-06-01

    An accelerator can be used to increase the safety and neutron economy of a power reactor and transmuter of long-lived radioactive wastes, such as minor actinides and fission products, by providing neutrons for its subcritical operation. Instead of the rather large subcriticality of k=0.9-0.95 which we originally proposed for such a transmutor, we propose to use a slightly subcritical reactor, such as k=0.99, which will avoid many of the technical difficulties that are associated with large subcriticality, such as localized power peaking, radiation damage due to the injection of medium-energy protons, the high current accelerator, and the requirement for a long beam-expansion section. We analyzed the radiation damage of the target area, and discuss the necessity of high neutron economy to transmute the long lived fission products using the fast reactor system.

  17. An investigation into the effectiveness of smartphone experiments on students’ conceptual knowledge about acceleration

    NASA Astrophysics Data System (ADS)

    Mazzella, Alessandra; Testa, Italo

    2016-09-01

    This study is a first attempt to investigate effectiveness of smartphone-based activities on students’ conceptual understanding of acceleration. 143 secondary school students (15–16 years old) were involved in two types of activities: smartphone- and non-smartphone activities. The latter consisted in data logging and ‘cookbook’ activities. For the sake of comparison, all activities featured the same phenomena, i.e., the motion on an inclined plane and pendulum oscillations. A pre-post design was adopted, using open questionnaires as probes. Results show only weak statistical differences between the smartphone and non-smartphone groups. Students who followed smartphone activities were more able to design an experiment to measure acceleration and to correctly describe acceleration in a free fall motion. However, students of both groups had many difficulties in drawing acceleration vector along the trajectory of the studied motion. Results suggest that smartphone-based activities may be effective substitutes of traditional experimental settings and represent a valuable aid for teachers who want to implement laboratory activities at secondary school level. However, to achieve a deeper conceptual understanding of acceleration, some issues need to be addressed: what is the reference system of the built-in smartphone sensor; relationships between smartphone acceleration graphs and experimental setup; vector representation of the measured acceleration.

  18. The Gerbil Jar: A Basic Home Experience in Operant Conditioning.

    ERIC Educational Resources Information Center

    Plant, L.

    1980-01-01

    Explains how a teaching method such as allowing students to raise gerbils at home can encourage students to gain experience with the fundamental techniques of operant conditioning which are otherwise generally unavailable to students in large introductory psychology courses. (DB)

  19. Modeling laser wakefield accelerator experiments with ultrafast particle-in-cell simulations in boosted frames

    SciTech Connect

    Martins, S. F.; Fonseca, R. A.; Vieira, J.; Silva, L. O.

    2010-05-15

    The development of new laser systems at the 10 Petawatt range will push laser wakefield accelerators to novel regimes, for which theoretical scalings predict the possibility to accelerate electron bunches up to tens of GeVs in meter-scale plasmas. Numerical simulations will play a crucial role in testing, probing, and optimizing the physical parameters and the setup of future experiments. Fully kinetic simulations are computationally very demanding, pushing the limits of today's supercomputers. In this paper, the recent developments in the OSIRIS framework [R. A. Fonseca et al., Lect. Notes Comput. Sci. 2331, 342 (2002)] are described, in particular the boosted frame scheme, which leads to a dramatic change in the computational resources required to model laser wakefield accelerators. Results from one-to-one modeling of the next generation of laser systems are discussed, including the confirmation of electron bunch acceleration to the energy frontier.

  20. Terminal-area STOL operating systems experiments program

    NASA Technical Reports Server (NTRS)

    Smith, D. W.; Watson, D.; Christensen, J. V.

    1972-01-01

    A system study to determine the application of short takeoff aircraft for a high speed, short haul air transportation service was conducted. The study focused on developing information which will aid in choosing system concepts, design criteria, operating procedures, landing guidance systems, air traffic control systems, and airborne avionics and flight control systems. A terminal area STOL operating system experiments program was developed. The objectives, program approach, program schedule, typical experiments, research facilities to be used, and program status are discussed.

  1. Charging and the cross-field discharge during electron accelerator operation on a rocket

    NASA Technical Reports Server (NTRS)

    Kellogg, Paul J.; Monson, Steven J.

    1988-01-01

    Preliminary results are presented from experiments to study the neutralization processes around an electron beam emitting rocket. The rocket, SCEX II, was flown on January 31, 1987 from Alaska, with a payload consisting of two independent electron accelerators and two arms with conducting elements to act as Langmuir probes and to measure floating potentials. It was expected that electrons in the strong electric fields around the charged rocket would gain sufficient energy to ionize neutrals, producing ions which would be hurled outward at energies up to the rocket potential. Three hemispherical retarding potential analyzers were ejected from the main payload to measure these ions. The measurements show that fields sufficient to accelerate electrons to ionizing energies were present around the rocket.

  2. 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. PMID:23155997

  3. Unit Operation Experiment Linking Classroom with Industrial Processing

    ERIC Educational Resources Information Center

    Benson, Tracy J.; Richmond, Peyton C.; LeBlanc, Weldon

    2013-01-01

    An industrial-type distillation column, including appropriate pumps, heat exchangers, and automation, was used as a unit operations experiment to provide a link between classroom teaching and real-world applications. Students were presented with an open-ended experiment where they defined the testing parameters to solve a generalized problem. The…

  4. Laser-based acceleration for nuclear physics experiments at ELI-NP

    NASA Astrophysics Data System (ADS)

    Tesileanu, O.; Asavei, Th.; Dancus, I.; Gales, S.; Negoita, F.; Turcu, I. C. E.; Ursescu, D.; Zamfir, N. V.

    2016-05-01

    As part of the Extreme Light pan-European research infrastructure, Extreme Light Infrastructure - Nuclear Physics (ELI-NP) in Romania will focus on topics in Nuclear Physics, fundamental Physics and applications, based on very intense photon beams. Laser-based acceleration of electrons, protons and heavy ions is a prerequisite for a multitude of laser-driven nuclear physics experiments already proposed by the international research community. A total of six outputs of the dual-amplification chain laser system, two of 100TW, two of 1PW and two of 10PW will be employed in 5 experimental areas, with the possibility to use long and short focal lengths, gas and solid targets, reaching the whole range of laser acceleration processes. We describe the main techniques and expectations regarding the acceleration of electrons, protons and heavy nuclei at ELI-NP, and some physics cases for which these techniques play an important role in the experiments.

  5. Acceleration of heavy and light particles in turbulence: Comparison between experiments and direct numerical simulations

    NASA Astrophysics Data System (ADS)

    Volk, R.; Calzavarini, E.; Verhille, G.; Lohse, D.; Mordant, N.; Pinton, J.-F.; Toschi, F.

    2008-08-01

    We compare experimental data and numerical simulations for the dynamics of inertial particles with finite density in turbulence. In the experiment, bubbles and solid particles are optically tracked in a turbulent flow of water using an Extended Laser Doppler Velocimetry technique. The probability density functions (PDF) of particle accelerations and their auto-correlation in time are computed. Numerical results are obtained from a direct numerical simulation in which a suspension of passive pointwise particles is tracked, with the same finite density and the same response time as in the experiment. We observe a good agreement for both the variance of acceleration and the autocorrelation time scale of the dynamics; small discrepancies on the shape of the acceleration PDF are observed. We discuss the effects induced by the finite size of the particles, not taken into account in the present numerical simulations.

  6. Shifting from Production to Service to Experience-Based Operations

    NASA Astrophysics Data System (ADS)

    Angelis, Jannis; de Lima, Edson Pinheiro

    This chapter covers the shift in focus of value added business operations from ­production to services, and in turn, to experience-based operations where customer involvement itself becomes part of the offering. The shift has significant implications for how businesses are managed. The greater service focus affects the firm's unique value proposition, which necessitates considerations on strategy, supplier relations, post-sale offerings and so on. Meanwhile, the inclusion of customer ­experiences affect the way operations are designed and employed so that these are structurally systematically captured and capitalised.

  7. Operating experience review of an INL gas monitoring system

    SciTech Connect

    Cadwallader, Lee C.; DeWall, K. G.; Herring, J. S.

    2015-03-12

    This article describes the operations of several types of gas monitors in use at the Idaho National Laboratory (INL) High Temperature Electrolysis Experiment (HTE) laboratory. The gases monitored in the lab room are hydrogen, carbon monoxide, carbon dioxide, and oxygen. The operating time, calibration, and both actual and unwanted alarms are described. The calibration session time durations are described. In addition, some simple calculations are given to estimate the reliability of these monitors and the results are compared to operating experiences of other types of monitors.

  8. Examining Nontraditional Graduate Students' Academic Writing Experiences in an Accelerated Adult Program

    ERIC Educational Resources Information Center

    Crite, Charles E., Jr.

    2013-01-01

    The academic writing competencies of nontraditional graduate students enrolled in accelerated graduate programs have become a growing concern for many higher learning educators in those programs. The purpose of this nonexperimental quantitative study was to examine the writing experiences that impacted nontraditional graduate students enrolled in…

  9. School Counselors' Perceptions and Experience with Acceleration as a Program Option for Gifted and Talented Students

    ERIC Educational Resources Information Center

    Wood, Susannah; Portman, Tarrell Awe Agahe; Cigrand, Dawnette L.; Colangelo, Nicholas

    2010-01-01

    This article presents findings from a national survey of 149 practicing school counselors who are members of the American School Counselor Association. The survey gathered information on school counselors' perceptions of and experiences with acceleration as a program option for gifted students. Results indicate that, although school counselors'…

  10. The Gift of Time: Today's Academic Acceleration Case Study Voices of Experience

    ERIC Educational Resources Information Center

    Scheibel, Susan Riley

    2010-01-01

    The purpose of this qualitative case study was to examine today's academic acceleration from the lived experience and perspectives of two young adults whose education was shortened, thereby allowing them the gift of time. Through personal interviews, parent interviews, and physical artifacts, the researcher gained a complex, holistic understanding…

  11. Recent results from polarization experiments at the LHEP-JINR Accelerator

    SciTech Connect

    Ladygin, V. P.; Azhgirey, L. S.; Gurchin, Yu. V.; Isupov, A. Yu.; Krasnov, V. A.; Khrenov, A. N.; Kiselev, A. S.; Kizka, V. A.; Kurilkin, A. K.; Kurilkin, P. K.; Livanov, A. N.; Ladygina, N. B.; Malakhov, A. I.; Piyadin, S. M.; Reznikov, S. G.; Shikhalev, M. A.; Vasiliev, T. A.; Uesaka, T.; Kawabata, T.; Sakaguchi, S.

    2008-10-13

    The review of recent results from polarization experiments performed at LHEP-JINR Accelerator Complex in a GeV range is given. The current status of the spin program at Nuclotron as well as its further continuation with new high intensity polarized deuterons ion source is discussed.

  12. First experiments on neutron detection on the accelerator-based source for boron neutron capture therapy

    NASA Astrophysics Data System (ADS)

    Kuznetsov, A. S.; Malyshkin, G. N.; Makarov, A. N.; Sorokin, I. N.; Sulyaev, Yu. S.; Taskaev, S. Yu.

    2009-04-01

    A pilot accelerator-based source of epithermal neutrons, which is intended for wide application in clinics for boron neutron capture therapy, has been constructed at the Budker Institute of Nuclear Physics (Novosibirsk). A stationary proton beam has been obtained and near-threshold neutron generation regime has been realized. Results of the first experiments on neutron generation using the proposed source are described.

  13. Starting Where the Student Is: An Experiment in Accelerated Graduate Social Work Education

    ERIC Educational Resources Information Center

    Eades, Joe C.

    1976-01-01

    A description and interim evaluation of an experimental accelerated master's degree program is presented. The program is designed for students whose undergraduate preparation, work experience, and performance on a qualifying examination suggest that they can benefit from a curriculum that builds directly upon their previous educational and work…

  14. Using a mobile phone acceleration sensor in physics experiments on free and damped harmonic oscillations

    NASA Astrophysics Data System (ADS)

    Carlos Castro-Palacio, Juan; Velázquez-Abad, Luisberis; Giménez, Marcos H.; Monsoriu, Juan A.

    2013-06-01

    We have used a mobile phone acceleration sensor, and the Accelerometer Monitor application for Android, to collect data in physics experiments on free and damped oscillations. Results for the period, frequency, spring constant, and damping constant agree very well with measurements obtained by other methods. These widely available sensors are likely to find increased use in instructional laboratories.

  15. Operating Experience of the Tritium Laboratory at CRL

    SciTech Connect

    Gallagher, C.L.; McCrimmon, K.D.

    2005-07-15

    The Chalk River Laboratories Tritium Laboratory has been operating safely and reliably for over 20 years. Safe operations are achieved through proper management, supervision, training and using approved operating procedures and techniques. Reliability is achieved through appropriate equipment selection, routine equipment surveillance testing and routine preventative maintenance. This paper summarizes the laboratory's standard operating protocols and formal compliance programs followed to ensure safe operations. The paper will also review the general set-up of the laboratory and will focus on the experience gained with the operation of various types of equipment such as tritium monitors, tritium analyzers, pumps, purification systems and other systems used in the laboratory during its 20 years of operation.

  16. EBR-II: twenty years of operating experience

    SciTech Connect

    Lentz, G.L.; Buschman, H.W.; Smith, R.N.

    1985-01-01

    Experimental Breeder Reactor No. 2 (EBR-II) is an unmoderated, sodium-cooled reactor with a design power of 62.5 MWt. For the last 20 years EBR-II has operated safely, has demonstrated stable operating characteristics, has shown excellent performance of its sodium components, and has had an excellent plant factor. These years of operating experience provide a valuable resource to the nuclear community for the development and design of future liquid metal fast reactors. This report provides a brief description of the EBR-II plant and its early operating experience, describes some recent problems of interest to the nuclear community, and also mentions some of the significant operating achievements of EBR-II. Finally, a few words and speculations on EBR-II's future are offered. 4 figs., 1 tab.

  17. Recent operating experiences and programs at EBR-II

    SciTech Connect

    Lentz, G.L.

    1984-01-01

    Experimental Breeder Reactor No. II (EBR-II) is a pool-type, unmoderated, sodium-cooled reactor with a design power of 62.5 MWt and an electrical generation capability of 20 MW. It has been operated by Argonne National Laboratory for the US government for almost 20 years. During that time, it has operated safely and has demonstrated stable operating characteristics, high availability, and excellent performance of its sodium components. The 20 years of operating experience of EBR-II is a valuable resource to the nuclear community for the development and design of future LMFBR's. Since past operating experience has been extensively reported, this report will focus on recent programs and events.

  18. Simultaneous operation of two soft x-ray free-electron lasers driven by one linear accelerator

    NASA Astrophysics Data System (ADS)

    Faatz, B.; Plönjes, E.; Ackermann, S.; Agababyan, A.; Asgekar, V.; Ayvazyan, V.; Baark, S.; Baboi, N.; Balandin, V.; von Bargen, N.; Bican, Y.; Bilani, O.; Bödewadt, J.; Böhnert, M.; Böspflug, R.; Bonfigt, S.; Bolz, H.; Borges, F.; Borkenhagen, O.; Brachmanski, M.; Braune, M.; Brinkmann, A.; Brovko, O.; Bruns, T.; Castro, P.; Chen, J.; Czwalinna, M. K.; Damker, H.; Decking, W.; Degenhardt, M.; Delfs, A.; Delfs, T.; Deng, H.; Dressel, M.; Duhme, H.-T.; Düsterer, S.; Eckoldt, H.; Eislage, A.; Felber, M.; Feldhaus, J.; Gessler, P.; Gibau, M.; Golubeva, N.; Golz, T.; Gonschior, J.; Grebentsov, A.; Grecki, M.; Grün, C.; Grunewald, S.; Hacker, K.; Hänisch, L.; Hage, A.; Hans, T.; Hass, E.; Hauberg, A.; Hensler, O.; Hesse, M.; Heuck, K.; Hidvegi, A.; Holz, M.; Honkavaara, K.; Höppner, H.; Ignatenko, A.; Jäger, J.; Jastrow, U.; Kammering, R.; Karstensen, S.; Kaukher, A.; Kay, H.; Keil, B.; Klose, K.; Kocharyan, V.; Köpke, M.; Körfer, M.; Kook, W.; Krause, B.; Krebs, O.; Kreis, S.; Krivan, F.; Kuhlmann, J.; Kuhlmann, M.; Kube, G.; Laarmann, T.; Lechner, C.; Lederer, S.; Leuschner, A.; Liebertz, D.; Liebing, J.; Liedtke, A.; Lilje, L.; Limberg, T.; Lipka, D.; Liu, B.; Lorbeer, B.; Ludwig, K.; Mahn, H.; Marinkovic, G.; Martens, C.; Marutzky, F.; Maslocv, M.; Meissner, D.; Mildner, N.; Miltchev, V.; Molnar, S.; Mross, D.; Müller, F.; Neumann, R.; Neumann, P.; Nölle, D.; Obier, F.; Pelzer, M.; Peters, H.-B.; Petersen, K.; Petrosyan, A.; Petrosyan, G.; Petrosyan, L.; Petrosyan, V.; Petrov, A.; Pfeiffer, S.; Piotrowski, A.; Pisarov, Z.; Plath, T.; Pototzki, P.; Prandolini, M. J.; Prenting, J.; Priebe, G.; Racky, B.; Ramm, T.; Rehlich, K.; Riedel, R.; Roggli, M.; Röhling, M.; Rönsch-Schulenburg, J.; Rossbach, J.; Rybnikov, V.; Schäfer, J.; Schaffran, J.; Schlarb, H.; Schlesselmann, G.; Schlösser, M.; Schmid, P.; Schmidt, C.; Schmidt-Föhre, F.; Schmitz, M.; Schneidmiller, E.; Schöps, A.; Scholz, M.; Schreiber, S.; Schütt, K.; Schütz, U.; Schulte-Schrepping, H.; Schulz, M.; Shabunov, A.; Smirnov, P.; Sombrowski, E.; Sorokin, A.; Sparr, B.; Spengler, J.; Staack, M.; Stadler, M.; Stechmann, C.; Steffen, B.; Stojanovic, N.; Sychev, V.; Syresin, E.; Tanikawa, T.; Tavella, F.; Tesch, N.; Tiedtke, K.; Tischer, M.; Treusch, R.; Tripathi, S.; Vagin, P.; Vetrov, P.; Vilcins, S.; Vogt, M.; de Zubiaurre Wagner, A.; Wamsat, T.; Weddig, H.; Weichert, G.; Weigelt, H.; Wentowski, N.; Wiebers, C.; Wilksen, T.; Willner, A.; Wittenburg, K.; Wohlenberg, T.; Wortmann, J.; Wurth, W.; Yurkov, M.; Zagorodnov, I.; Zemella, J.

    2016-06-01

    Extreme-ultraviolet to x-ray free-electron lasers (FELs) in operation for scientific applications are up to now single-user facilities. While most FELs generate around 100 photon pulses per second, FLASH at DESY can deliver almost two orders of magnitude more pulses in this time span due to its superconducting accelerator technology. This makes the facility a prime candidate to realize the next step in FELs—dividing the electron pulse trains into several FEL lines and delivering photon pulses to several users at the same time. Hence, FLASH has been extended with a second undulator line and self-amplified spontaneous emission (SASE) is demonstrated in both FELs simultaneously. FLASH can now deliver MHz pulse trains to two user experiments in parallel with individually selected photon beam characteristics. First results of the capabilities of this extension are shown with emphasis on independent variation of wavelength, repetition rate, and photon pulse length.

  19. Loss of Rassf1a co-operates with ApcMin to accelerate intestinal tumourigenesis

    PubMed Central

    van der Weyden, L.; Arends, M.J.; Dovey, O.M.; Harrison, H. L.; Lefebvre, G.; Conte, N.; Gergely, F.V.; Bradley, A.; Adams, D.J.

    2013-01-01

    Promoter methylation of the RAS-association domain family 1, isoform A gene (RASSF1A) is one of the most frequent events found in human tumours. In this study we set out to test the hypothesis that loss of Rassf1a can co-operate with inactivation of the adenomatous polyposis coli (Apc) gene to accelerate intestinal tumourigenesis using the Apc-Min (ApcMin/+) mouse model, as mutational or deletional inactivation of APC is a frequent early event in the genesis of intestinal cancer. Further, loss of RASSF1A has also been reported to occur in premalignant adenomas of the bowel. RASSF1A has been implicated in an array of pivotal cellular processes, including regulation of the cell cycle, apoptosis, microtubule stability and most recently in the β-catenin signalling pathway. By interbreeding isoform specific Rassf1a knockout mice with Apc+/Min mice we showed that loss of Rassf1a results in a significant increase in adenomas of the small intestine and accelerated intestinal tumourigenesis leading to the earlier death of adenocarcinoma-bearing mice and decreased overall survival. Comparative genomic hybridization of adenomas from Rassf1a−/−; Apc+/Min mice revealed no evidence of aneuploidy or gross chromosomal instability (no difference to adenomas from Rassf1a+/+; Apc+/Min mice). Immunohistochemical analysis of adenomas revealed increased nuclear β-catenin accumulation in adenomas from Rassf1a−/−; Apc+/Min mice, compared to those from Rassf1a+/+; Apc+/Min mice, but no differences in proliferation marker (Ki67) staining patterns. Collectively these data demonstrate co-operation between inactivation of Rassf1a and Apc resulting in accelerated intestinal tumourigenesis, with adenomas showing increased nuclear accumulation of β-catenin, supporting a mechanistic link via loss of the known interaction of Rassf1 with β-TrCP that usually mediates degradation of β-catenin. PMID:18391979

  20. Development of a subway operation incident delay model using accelerated failure time approaches.

    PubMed

    Weng, Jinxian; Zheng, Yang; Yan, Xuedong; Meng, Qiang

    2014-12-01

    This study aims to develop a subway operational incident delay model using the parametric accelerated time failure (AFT) approach. Six parametric AFT models including the log-logistic, lognormal and Weibull models, with fixed and random parameters are built based on the Hong Kong subway operation incident data from 2005 to 2012, respectively. In addition, the Weibull model with gamma heterogeneity is also considered to compare the model performance. The goodness-of-fit test results show that the log-logistic AFT model with random parameters is most suitable for estimating the subway incident delay. First, the results show that a longer subway operation incident delay is highly correlated with the following factors: power cable failure, signal cable failure, turnout communication disruption and crashes involving a casualty. Vehicle failure makes the least impact on the increment of subway operation incident delay. According to these results, several possible measures, such as the use of short-distance and wireless communication technology (e.g., Wifi and Zigbee) are suggested to shorten the delay caused by subway operation incidents. Finally, the temporal transferability test results show that the developed log-logistic AFT model with random parameters is stable over time. PMID:25171521

  1. Effects of unsteady flow and real gas equations of state on high pressure ram accelerator operation

    NASA Astrophysics Data System (ADS)

    Bundy, Christopher Michael

    2001-07-01

    An experimental and theoretical investigation of the conditions which enable thermally choked ram acceleration at fill pressures greater than 5 MPa is presented. A set of experimental parameters was determined which enabled projectiles to be accelerated continuously in propellants at 20 MPa for distances up to 4 m. The operating conditions which permit thermally choked operation at 20 MPa are considerably different from those at 5 MPa and below; the effects of initial velocity, propellant composition, projectile design, and obturator design on high pressure operation were investigated. During thermally choked operation at high pressure, the velocity-distance profile is overpredicted by a quasi-steady control volume approach for thrust determination. A revision to the control volume model accounting for unsteady flow effects was developed and presented here. The unsteady model indicates that the thrust coefficient-Mach number profile obtained for high pressure conditions is consistently lower than that obtained with the quasi-steady model, due to unsteady momentum transfer to the gas in the control volume surrounding the projectile, an effect considered negligible at 5 MPa and below. This analytical deviation correlates with high pressure experimental results. When the unsteady model incorporates the heat release behavior predicted for a real gas equation of state, good agreement is obtained with experimental velocity-distance data. A model for predicting sonic diffuser unstart under unsteady flow conditions is also presented; the model predictions agree well with experimental results. Both models indicate that the mass of fluid in a control volume, when on the order of the mass of the surrounding system, has a significant effect on the body forces acting on the system under unsteady flow conditions. The unsteady models quantify this effect by showing that thrust in an unsteady flow propulsion system is not directly proportional to pressure, and that supersonic

  2. 78 FR 52933 - Strengthening the Operating Framework and Furthering the Objectives of Coalition for Accelerating...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-27

    ... Objectives of Coalition for Accelerating Standards and Therapies Initiative (U24) AGENCY: Food and Drug... Objectives The CFAST Initiative aims to accelerate clinical research and medical product development...

  3. CTS (Hermes): United States experiments and operations summary

    NASA Technical Reports Server (NTRS)

    Donoughe, P. L.; Hunczak, H. R.

    1977-01-01

    The Communications Technology Satellite, launched in January 1976 and embodying the highest power transmitter in a communications satellite, was considered. As a joint program between the U.S. and Canada, close coordination of the two countries was necessitated since the management and control of experiments were done in real time. Criteria used by NASA for acceptance of the United States experiments are noted and acceptance procedures are discussed. The category for each accepted experiment is given. The modus operandi employed for the U.S. experiments in the areas of management, coordination, liaison, and real time operation are described. Some of the highlights associated with satellite utilization are given.

  4. Experiments in sensing transient rotational acceleration cues on a flight simulator

    NASA Technical Reports Server (NTRS)

    Parrish, R. V.

    1979-01-01

    Results are presented for two transient motion sensing experiments which were motivated by the identification of an anomalous roll cue (a 'jerk' attributed to an acceleration spike) in a prior investigation of realistic fighter motion simulation. The experimental results suggest the consideration of several issues for motion washout and challenge current sensory system modeling efforts. Although no sensory modeling effort is made it is argued that such models must incorporate the ability to handle transient inputs of short duration (some of which are less than the accepted latency times for sensing), and must represent separate channels for rotational acceleration and velocity sensing.

  5. US nuclear power plant operating cost and experience summaries

    SciTech Connect

    Kohn, W.E.; Reid, R.L.; White, V.S.

    1998-02-01

    NUREG/CR-6577, U.S. Nuclear Power Plant Operating Cost and Experience Summaries, has been prepared to provide historical operating cost and experience information on U.S. commercial nuclear power plants. Cost incurred after initial construction are characterized as annual production costs, representing fuel and plant operating and maintenance expenses, and capital expenditures related to facility additions/modifications which are included in the plant capital asset base. As discussed in the report, annual data for these two cost categories were obtained from publicly available reports and must be accepted as having different degrees of accuracy and completeness. Treatment of inconclusive and incomplete data is discussed. As an aid to understanding the fluctuations in the cost histories, operating summaries for each nuclear unit are provided. The intent of these summaries is to identify important operating events; refueling, major maintenance, and other significant outages; operating milestones; and significant licensing or enforcement actions. Information used in the summaries is condensed from annual operating reports submitted by the licensees, plant histories contained in Nuclear Power Experience, trade press articles, and the Nuclear Regulatory Commission (NRC) web site (www.nrc.gov).

  6. Vibration isolation technology: Sensitivity of selected classes of experiments to residual accelerations

    NASA Technical Reports Server (NTRS)

    Alexander, J. Iwan D.

    1990-01-01

    The solution was sought of a 2-D axisymmetric moving boundary problem for the sensitivity of isothermal and nonisothermal liquid columns and the sensitivity of thermo-capillary flows to buoyancy driven convection caused by residual accelerations. The sensitivity of a variety of space experiments to residual accelerations are examined. In all the cases discussed, the sensitivity is related to the dynamic response of a fluid. In some cases the sensitivity can be defined by the magnitude of the response of the velocity field. This response may involve motion of the fluid associated with internal density gradients, or the motion of a free liquid surface. For fluids with internal density gradients, the type of acceleration to which the experiment is sensitive will depend on whether buoyancy driven convection must be small in comparison to other types of fluid motion (such as thermocapillary flow), or fluid motion must be suppressed or eliminated (such as in diffusion studies, or directional solidification experiments). The effect of the velocity on the composition and temperature field must be considered, particularly in the vicinity of the melt crystal interface. As far as the response to transient disturbances is concerned the sensitivity is determined by both the magnitude and frequency the acceleration and the characteristic momentum and solute diffusion times.

  7. Neutron production from a mobile linear accelerator operating in electron mode for intraoperative radiation therapy

    NASA Astrophysics Data System (ADS)

    Loi, G.; Dominietto, M.; Cannillo, B.; Ciocca, M.; Krengli, M.; Mones, E.; Negri, E.; Brambilla, M.

    2006-02-01

    Intraoperative electron beam radiotherapy is increasingly performed using mobile linac delivering therapeutic radiation doses in unshielded operating rooms. While no special neutron-shielding problem should arise for operation at 10 MeV or less, it is not clear whether this holds true for operation at higher energies. This paper reports the measured neutron production from a Mobetron mobile electron linac, operated at 12 MeV, and compares the results with those from a conventional linac, also operated at 12 MeV in electron mode. Neutron leakage measurements were performed by means of passive bubble detectors in the scattering foil, patient and floor planes. Neutron dose equivalent rates per unit of electron dose delivered by the Mobetron at its normal treatment distance (50 cm SSD) were 0.33 µSv Gy-1 at the accelerator head, 0.18 µSv Gy-1 in the patient plane at 15 cm from the beam axis and 0.31 µSv Gy-1 at the floor plane, on the beam axis and under the beam stopper. For a weekly workload of 250 Gy, the weekly neutron dose equivalents at 12 MeV for the Mobetron at a distance of 300 cm from the scattering foil were 14.3 and 1.7 µSv/week for floor below and adjoining areas on the same floor, respectively. Neutron dose equivalent rates generated from Mobetron are at least one order of magnitude lower than ones produced by a conventional linac operated at the same energy in electron mode. Mobetron can be used at 12 MeV in an unshielded operating room for a weekly workload of up to 250 Gy if the bremsstrahlung x-rays are shielded to negligible levels.

  8. The MESA accelerator

    SciTech Connect

    Aulenbacher, Kurt

    2013-11-07

    The MESA accelerator will operate for particle and nuclear physics experiments in two different modes. A first option is conventional c.w. acceleration yielding 150-200MeV spin-polarized external beam. Second, MESA will be operated as a superconducting multi-turn energy recovery linac (ERL), opening the opportunity to perform experiments with a windowless target with beam current of up to 10 mA. The perspectives for innovative experiments with such a machine are discussed together with a sketch of the accelerator physics issues that have to be solved.

  9. Ventilation Systems Operating Experience Review for Fusion Applications

    SciTech Connect

    Cadwallader, Lee Charles

    1999-12-01

    This report is a collection and review of system operation and failure experiences for air ventilation systems in nuclear facilities. These experiences are applicable for magnetic and inertial fusion facilities since air ventilation systems are support systems that can be considered generic to nuclear facilities. The report contains descriptions of ventilation system components, operating experiences with these systems, component failure rates, and component repair times. Since ventilation systems have a role in mitigating accident releases in nuclear facilities, these data are useful in safety analysis and risk assessment of public safety. An effort has also been given to identifying any safety issues with personnel operating or maintaining ventilation systems. Finally, the recommended failure data were compared to an independent data set to determine the accuracy of individual values. This comparison is useful for the International Energy Agency task on fusion component failure rate data collection.

  10. STS-40 orbital acceleration research experiment flight results during a typical sleep period

    NASA Technical Reports Server (NTRS)

    Blanchard, Robert C.; Nicholson, John Y.; Ritter, James R.

    1992-01-01

    The Orbital Acceleration Research Experiment (OARE), an electrostatic accelerometer package with complete on-orbit calibration capabilities was flown aboard Shuttle on STS-40. The instrument is designed to measure and record the Shuttle aerodynamic acceleration environment from the free molecule flow regime through the rarefied flow transition into the hypersonic continuum regime. Because of its sensitivity, the OARE instrument detects aerodynamic behavior of the Shuttle while in low-earth orbit. A 2-h orbital time period on day seven of the mission, when the crew was asleep and other spacecraft activities were at a minimum, was examined. Examination of the model with the flight data shows the instrument to be sensitive to all major expected low-frequency acceleration phenomena; however, some erratic instrument bias behavior persists in two axes. In these axes, the OARE data can be made to match a comprehensive atmospheric-aerodynamic model by making bias adjustments and slight liner corrections for drift.

  11. Parabolic dish test site: History and operating experience

    NASA Technical Reports Server (NTRS)

    Selcuk, M. K. (Compiler)

    1985-01-01

    The parabolic dish test site (PDTS) was established for testing point-focusing solar concentrator systems operating at temperatures approaching 1650 C. Among tests run were evaluation and performance characterization of parabolic dish concentrators, receivers, power conversion units, and solar/fossil-fuel hybrid systems. The PDTS was fully operational until its closure in June, 1984. The evolution of the test program, a chronological listing of the experiments run, and data summaries for most of the tests conducted are presented.

  12. The ANL experiment for a wake field accelerator using an rf structure

    SciTech Connect

    Ruggiero, A.G.; Schoessow, P.; Simpson, J.

    1986-08-27

    Experiments are planned at ANL to study a new accelerating concept that has been developed during the last few years named the WAKEATRON. This requires a very special, simple configuration of the beams and of the rf structure involved. The basic concepts are explained. Like most proposed experimental work, this too was initiated by a considerable amount of computational work, both analytical and numerical, on which we would like to report. We will then describe details of the planned experiments we will carry out at ANL to check some of our predictions for this concept. These experiments concentrate on beam and cavity geometry applicable to the Wakeatron.

  13. The LACARA Vacuum Laser Accelerator Experiment: Beam Positioning and Alignment in a Strong Magnetic Field

    SciTech Connect

    Shchelkunov, Sergey V.; Marshall, T. C.; Hirshfield, J. L.; Wang, Changbiao; LaPointe, M. A.

    2006-11-27

    LACARA (laser cyclotron auto-resonance accelerator) is a vacuum laser accelerator of electrons that is under construction at the Accelerator Test Facility (ATF), Brookhaven National Laboratory. It is expected that the experiment will be assembled by September 2006; this paper presents progress towards this goal. According to numerical studies, as an electron bunch moves along the LACARA solenoidal magnetic field ({approx}5.2 T, length {approx}1 m), it will be accelerated from 50 to {approx}75 MeV by interacting with a 0.8 TW Gaussian-mode circularly polarized optical pulse provided by the ATF CO2 10.6{mu}m laser system. The LACARA laser transport optics must handle 10 J and be capable of forming a Gaussian beam inside the solenoid with a 1.4 mm waist and a Rayleigh range of 60 cm. The electron optics must transport a bunch having input emittance of 0.015 mm-mrad and 100 {mu}m waist through the magnet. Precision alignment between the electron beam and the solenoid magnetic axis is required, and a method to achieve this is described in detail. Emittance- filtering may be necessary to yield an accelerated bunch having a narrow ({approx}1%) energy-spread.

  14. Helicon Plasma Injector and Ion Cyclotron Acceleration Development in the VASIMR Experiment

    NASA Technical Reports Server (NTRS)

    Squire, Jared P.; Chang, Franklin R.; Jacobson, Verlin T.; McCaskill, Greg E.; Bengtson, Roger D.; Goulding, Richard H.

    2000-01-01

    In the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) radio frequency (rf) waves both produce the plasma and then accelerate the ions. The plasma production is done by action of helicon waves. These waves are circular polarized waves in the direction of the electron gyromotion. The ion acceleration is performed by ion cyclotron resonant frequency (ICRF) acceleration. The Advanced Space Propulsion Laboratory (ASPL) is actively developing efficient helicon plasma production and ICRF acceleration. The VASIMR experimental device at the ASPL is called VX-10. It is configured to demonstrate the plasma production and acceleration at the 10kW level to support a space flight demonstration design. The VX-10 consists of three electromagnets integrated into a vacuum chamber that produce magnetic fields up to 0.5 Tesla. Magnetic field shaping is achieved by independent magnet current control and placement of the magnets. We have generated both helium and hydrogen high density (>10(exp 18) cu m) discharges with the helicon source. ICRF experiments are underway. This paper describes the VX-10 device, presents recent results and discusses future plans.

  15. Motivation for proposed experimentation in the realm of accelerated E. M. systems: A preliminary design for an experiment

    NASA Technical Reports Server (NTRS)

    Post, E. J.

    1970-01-01

    An experiment, designed to determine the difference between fields-magnetic and electric-surrounding a uniformly moving charge as contrasted with the fields surrounding an accelerated charge, is presented. A thought experiment is presented to illustrate the process.

  16. Flight Validation of On-Demand Operations: The Deep Space One Beacon Monitor Operations Experiment

    NASA Technical Reports Server (NTRS)

    Wyatt, Jay; Sherwood, Rob; Sue, Miles; Szijjarto, John

    2000-01-01

    After a brief overview of the operational concept, this paper will provide a detailed description of the _as-flown_ flight software components, the DS1 experiment plan, and experiment results to date. Special emphasis will be given to experiment results and lessons learned since the basic system design has been previously reported. Mission scenarios where beacon operations is highly applicable will be described. Detailed cost savings estimates for a sample science mission will be provided as will cumulative savings that are possible over the next fifteen years of NASA missions.

  17. The High-Luminosity upgrade of the LHC: Physics and Technology Challenges for the Accelerator and the Experiments

    NASA Astrophysics Data System (ADS)

    Schmidt, Burkhard

    2016-04-01

    In the second phase of the LHC physics program, the accelerator will provide an additional integrated luminosity of about 2500/fb over 10 years of operation to the general purpose detectors ATLAS and CMS. This will substantially enlarge the mass reach in the search for new particles and will also greatly extend the potential to study the properties of the Higgs boson discovered at the LHC in 2012. In order to meet the experimental challenges of unprecedented pp luminosity, the experiments will need to address the aging of the present detectors and to improve the ability to isolate and precisely measure the products of the most interesting collisions. The lectures gave an overview of the physics motivation and described the conceptual designs and the expected performance of the upgrades of the four major experiments, ALICE, ATLAS, CMS and LHCb, along with the plans to develop the appropriate experimental techniques and a brief overview of the accelerator upgrade. Only some key points of the upgrade program of the four major experiments are discussed in this report; more information can be found in the references given at the end.

  18. Advances in X-Band TW Accelerator Structures Operating in the 100 MV/M Regime

    SciTech Connect

    Higo, Toshiyasu; Higashi, Yasuo; Matsumoto, Shuji; Yokoyama, Kazue; Adolphsen, Chris; Dolgashev, Valery; Jensen, Aaron; Laurent, Lisa; Tantawi, Sami; Wang, Faya; Wang, Juwen; Dobert, Steffen; Grudiev, Alexej; Riddone, Germana; Wuensch, Walter; Zennaro, Riccardo; /CERN

    2012-07-05

    A CERN-SLAC-KEK collaboration on high gradient X-band accelerator structure development for CLIC has been ongoing for three years. The major outcome has been the demonstration of stable 100 MV/m gradient operation of a number of CLIC prototype structures. These structures were fabricated using the technology developed from 1994 to 2004 for the GLC/NLC linear collider initiative. One of the goals has been to refine the essential parameters and fabrication procedures needed to realize such a high gradient routinely. Another goal has been to develop structures with stronger dipole mode damping than those for GLC/NLC. The latter requires that the surface temperature rise during the pulse be higher, which may increase the breakdown rate. One structure with heavy damping has been RF processed and another is nearly finished. The breakdown rates of these structures were found to be higher by two orders of magnitude compared to those with equivalent acceleration mode parameters but without the damping features. This paper presents these results together with some of the earlier results from non-damped structures.

  19. Experiments on power optimization for displacement-constrained operation of a vibration energy harvester

    NASA Astrophysics Data System (ADS)

    Truong, Binh Duc; Phu Le, Cuong; Halvorsen, Einar

    2015-12-01

    This paper presents experiments on how to approach the physical limits on power from vibration energy harvesting under displacement-constrained operation. A MEMS electrostatic vibration energy harvester with voltage-control of the system stiffness is used for this purpose. The power saturation problem, when the proof mass displacement reaches maximum amplitude for sufficient acceleration amplitude, is shifted to higher accelerations by use of load optimization and tunable electromechanical coupling k2. Measurement results show that harvested power can be made to follow the optimal velocity-damped generator also for a range of accelerations that implies displacement constraints. Comparing to the saturated power, the power increases 1.5 times with the optimal load and an electromechanical coupling k2=8.7%. This value is 2.3 times for a higher coupling k2=17.9%. The obtained system effectiveness is beyond 60% under the optimization. This work also shows a first demonstration of reaching optimal power in the intermediate acceleration-range between the two extremes of maximum efficiency and maximum power transfer.

  20. Operation MEDIHC (Military Experience Directed into Health Careers). Final Report.

    ERIC Educational Resources Information Center

    Colorado Hospital Association, Denver.

    This Region VIII Operation MEDIHC (Military Experience Directed into Health Careers) comprehensive report covers the program's efforts to provide a state focal point of advice and assistance to all health-trained veterans seeking entrance into the civilian health services field during the period of June 1, 1970, through December 31, 1978. The…

  1. Effect of Inductive Coil Geometry on the Operating Characteristics of a Pulsed Inductive Plasma Accelerator

    NASA Technical Reports Server (NTRS)

    Hallock, Ashley K.; Polzin, Kurt A.; Kimberlin, Adam C.

    2012-01-01

    Operational characteristics of two separate inductive thrusters with coils of different cone angles are explored through thrust stand measurements and time-integrated, un- filtered photography. Trends in impulse bit measurements indicate that, in the present experimental configuration, the thruster with the inductive coil possessing a smaller cone angle produced larger values of thrust, in apparent contradiction to results of a previous thruster acceleration model. Areas of greater light intensity in photographs of thruster operation are assumed to qualitatively represent locations of increased current density. Light intensity is generally greater in images of the thruster with the smaller cone angle when compared to those of the thruster with the larger half cone angle for the same operating conditions. The intensity generally decreases in both thrusters for decreasing mass ow rate and capacitor voltage. The location of brightest light intensity shifts upstream for decreasing mass ow rate of propellant and downstream for decreasing applied voltage. Recognizing that there typically exists an optimum ratio of applied electric field to gas pressure with respect to breakdown efficiency, this result may indicate that the optimum ratio was not achieved uniformly over the coil face, leading to non-uniform and incomplete current sheet formation in violation of the model assumption of immediate formation where all the injected propellant is contained in a magnetically-impermeable current sheet.

  2. Rapid acceleration leads to rapid weakening in earthquake-like laboratory experiments

    USGS Publications Warehouse

    Chang, Jefferson C.; Lockner, David A.; Reches, Z.

    2012-01-01

    After nucleation, a large earthquake propagates as an expanding rupture front along a fault. This front activates countless fault patches that slip by consuming energy stored in Earth’s crust. We simulated the slip of a fault patch by rapidly loading an experimental fault with energy stored in a spinning flywheel. The spontaneous evolution of strength, acceleration, and velocity indicates that our experiments are proxies of fault-patch behavior during earthquakes of moment magnitude (Mw) = 4 to 8. We show that seismically determined earthquake parameters (e.g., displacement, velocity, magnitude, or fracture energy) can be used to estimate the intensity of the energy release during an earthquake. Our experiments further indicate that high acceleration imposed by the earthquake’s rupture front quickens dynamic weakening by intense wear of the fault zone.

  3. Rapid Acceleration Leads to Rapid Weakening in Earthquake-Like Laboratory Experiments

    NASA Astrophysics Data System (ADS)

    Chang, J. C.; Lockner, D. A.; Reches, Z.

    2012-10-01

    After nucleation, a large earthquake propagates as an expanding rupture front along a fault. This front activates countless fault patches that slip by consuming energy stored in Earth’s crust. We simulated the slip of a fault patch by rapidly loading an experimental fault with energy stored in a spinning flywheel. The spontaneous evolution of strength, acceleration, and velocity indicates that our experiments are proxies of fault-patch behavior during earthquakes of moment magnitude (Mw) = 4 to 8. We show that seismically determined earthquake parameters (e.g., displacement, velocity, magnitude, or fracture energy) can be used to estimate the intensity of the energy release during an earthquake. Our experiments further indicate that high acceleration imposed by the earthquake’s rupture front quickens dynamic weakening by intense wear of the fault zone.

  4. Development of integrated superconducting quadrupole doublet modules for operation in the SIS100 accelerator

    NASA Astrophysics Data System (ADS)

    Meier, J.; Bleile, A.; Ceballos Velasco, J.; Fischer, E.; Hess, G.; Macavei, J.; Spiller, P.

    2015-12-01

    The FAIR project (Facility for Antiproton and Ion Research) evolves and builds an international accelerator- and experimental facility for basic research activities in various fields of modern physics. Within the course of this project, integrated quadrupole doublet modules are in development. The quadrupole doublet modules provide a pair of superconducting main quadrupoles (focusing and defocusing), corrector magnets, cryogenic collimators and beam position monitors as integrated sets of ion-optical elements. Furthermore LHe cooled beam pipes and vacuum cold-warm transitions are used as ultra-high vacuum components for beam transportation. Superconducting bus bars are used for 13 kA current supply of the main quadrupole magnets. All components are integrated as one common cold mass into one cryostat. High temperature super conductor local current leads will be applied for the low current supply of corrector magnets. The quadrupole doublet modules will be operated in the SIS100 heavy ion accelerator, the core component of the FAIR project. A first version of a corrector magnet has already been manufactured at the Joint Institute for Nuclear Research (JINR), Russia, and is now ready for testing. The ion-optical lattice structure of SIS100 requires multiple configurations of named components. Eleven different configurations, organized in four categories, provide the required quadrupole doublet module setups. The high integration level of multiple ion-optical, mechanical and cryogenic functions, based on requirements of operation safety, is leading towards a sophisticated mechanical structure and cooling solution, to satisfy the demanding requirements on position preservation during thermal cycling. The mechanical and cryogenic design solutions will be discussed.

  5. International Space Station United States Orbital Segment Oxygen Generation System On-Orbit Operational Experience

    NASA Technical Reports Server (NTRS)

    Erickson, Robert J.; Howe, John, Jr.; Kulp, Galen W.; VanKeuren, Steven P.

    2008-01-01

    The International Space Station (ISS) United States Orbital Segment (USOS) Oxygen Generation System (OGS) was originally intended to be installed in ISS Node 3. The OGS rack delivery was accelerated, and it was launched to ISS in July of 2006 and installed in the US Laboratory Module. Various modification kits were installed to provide its interfaces, and the OGS was first activated in July of 2007 for 15 hours, In October of 2007 it was again activated for 76 hours with varied production rates and day/night cycling. Operational time in each instance was limited by the quantity of feedwater in a Payload Water Reservoir (PWR) bag. Feedwater will be provided by PWR bag until the USOS Water Recovery System (WRS) is delivered to SS in fall of 2008. This paper will discuss operating experience and characteristics of the OGS, as well as operational issues and their resolution.

  6. Target Operational Experience at the Spallation Neutron Source

    SciTech Connect

    Riemer, Bernie; Janney, Jim G; Kaminskas, Saulius; McClintock, David A; Rosenblad, Peter M

    2013-01-01

    The Spallation Neutron Source (SNS) at the Oak Ridge National Laboratory (ORNL) has operated at unprecedented power levels for a short-pulse spallation source. Target operations have been successful but not without difficulties. Three targets out of the eight used to date have ended life unexpectedly causing interruptions to the neutron science users. The first of a kind mercury target design experiences beam-pulse induced cavitation damage that is suspected in one of the target leaks. The two other targets suffered early failures due to defective welds. Diagnosing the causes of target leaks and understanding of the progression of cavitation erosion and radiation damage effects has made use of post-irradiation examination (PIE) capabilities. As a result of PIE, review of quality assurance practices and related investigations, design changes are being implemented and manufacturing oversight improved. This paper describes SNS target operating experience, including the more important observations and lessons learned.

  7. Recent operating experiences with steam generators in Japanese NPPs

    SciTech Connect

    Yashima, Seiji

    1997-02-01

    In 1994, the Genkai-3 of Kyushu Electric Power Co., Inc. and the Ikata-3 of Shikoku Electric Power Co., Inc. started commercial operation, and now 22 PWR plants are being operated in Japan. Since the first PWR plant now 22 PWR plants are being operated in was started to operate, Japanese PWR plants have had an operating experience of approx. 280 reactor-years. During that period, many tube degradations have been experienced in steam generators (SGs). And, in 1991, the steam generator tube rupture (SGTR) occurred in the Mihama-2 of Kansai Electric Power Co., Inc. However, the occurrence of tube degradation of SGs has been decreased by the instructions of the MITI as regulatory authorities, efforts of Electric Utilities, and technical support from the SG manufacturers. Here the author describes the recent SGs in Japan about the following points. (1) Recent Operating Experiences (2) Lessons learned from Mihama-2 SGTR (3) SG replacement (4) Safety Regulations on SG (5) Research and development on SG.

  8. Hosing Instability of the Drive Electron Beam in the E157 Plasma-Wakefield Acceleration Experiment at the Stanford Linear Accelerator

    SciTech Connect

    Blue, Brent Edward; /SLAC /UCLA

    2005-10-10

    In the plasma-wakefield experiment at SLAC, known as E157, an ultra-relativistic electron beam is used to both excite and witness a plasma wave for advanced accelerator applications. If the beam is tilted, then it will undergo transverse oscillations inside of the plasma. These oscillations can grow exponentially via an instability know as the electron hose instability. The linear theory of electron-hose instability in a uniform ion column predicts that for the parameters of the E157 experiment (beam charge, bunch length, and plasma density) a growth of the centroid offset should occur. Analysis of the E157 data has provided four critical results. The first was that the incoming beam did have a tilt. The tilt was much smaller than the radius and was measured to be 5.3 {micro}m/{delta}{sub z} at the entrance of the plasma (IP1.) The second was the beam centroid oscillates in the ion channel at half the frequency of the beam radius (betatron beam oscillations), and these oscillations can be predicted by the envelope equation. Third, up to the maximum operating plasma density of E157 ({approx}2 x 10{sup 14} cm{sup -3}), no growth of the centroid offset was measured. Finally, time-resolved data of the beam shows that up to this density, no significant growth of the tail of the beam (up to 8ps from the centroid) occurred even though the beam had an initial tilt.

  9. ARIEL E-linac Cryogenic System: Commissioning and First Operational Experience

    NASA Astrophysics Data System (ADS)

    Koveshnikov, A.; Bylinskii, I.; Hodgson, G.; Kishi, D.; Laxdal, R.; Ma, Y.; Nagimov, R.; Yosifov, D.

    2015-12-01

    The Advanced Rare IsotopE Laboratory (ARIEL) is a major expansion of the Isotope Separator and Accelerator (ISAC) facility at TRIUMF. A key part of the ARIEL project is a 10 mA 50 MeV continuous-wave superconducting radiofrequency (SRF) electron linear accelerator (e-linac). The 1.3 GHz SRF cavities are operated at 2 K. HELIAL LL helium liquefier by Air Liquide Advanced Technologies (ALAT) with a tuneable liquid helium (LHe) production was installed and commissioned in Q4’2013 [1]. It provides 4 K liquid helium to one injector and one accelerator cryomodules that were installed and tested in 2014. The 4 K to 2 K liquid helium transition is achieved on-board of each cryomodule. The cryoplant, LHe and LN2 distributions, sub-atmospheric (S/A) system and cryomodules were successfully commissioned and integrated into the e-linac cryogenic system. Required pressure regulation for both 4 K cryoplant in the Dewar and 2 K with the S/A system was achieved under simulated load. Final integration tests confirmed overall stable performance of the cryogenic system with two cryomodules installed. The paper presents details of the cryogenic system commissioning tests as well as highlights of the initial operational experience.

  10. Effect of Inductive Coil Geometry on the Operating Characteristics of a Pulsed Inductive Plasma Accelerator

    NASA Astrophysics Data System (ADS)

    Hallock, Ashley Kristin

    The effect of inductive coil geometry on the operating characteristics of a pulsed inductive plasma thruster is investigated analytically and experimentally. Coil inductance is measured as a function of the position of a simulated current sheet and modeled using finite element analysis to develop a two-dimensional semi-empirical inductance relation that is used to expand a circuit-based acceleration model from one to two dimensions. The model includes electromagnetic and gas-dynamic forces but excludes any process to translate radial plasma motion into axial motion. Furthermore a magnetically-impermeable current sheet encompassing all the propellant for a pulse is assumed to form immediately at the start of the pulse and at the surface of the inductive coil. The two-dimensional acceleration model is nondimensionalized, yielding a set of dimensionless performance scaling parameters. Model results indicate that the introduction of radial current sheet motion caused by a conical inductive coil geometry (versus a flat circular plate) increases the axial dynamic impedance parameter at which thrust efficiency is maximized and generally decreases the overall achievable thrust efficiency. Operational characteristics of two thrusters with inductive coils of different cone angles are explored through thrust stand measurements and time-integrated, unfiltered photography. Trends in impulse bit measurements indicate that, in the present configuration, the thruster with the inductive coil possessing a smaller cone angle produced larger values of thrust, in apparent contradiction to results of the model. Areas of increased light intensity in photographs of thruster operation are assumed to qualitatively represent locations of increased current density. Light intensity is generally greater in images of the thruster with the smaller cone angle when compared to those of the thruster with the larger half cone angle for the same operating conditions, and generally decreases in both

  11. Preliminary Results from the UCLA/SLAC Ultra-High Gradient CerenkovWakefield Accelerator Experiment

    SciTech Connect

    Thompson, M.C.; Badakov, H.; Rosenzweig, J.B.; Travish, G.; Hogan, M.; Ischebeck, R.; Kirby, N.; Siemann, R.; Walz, D.; Muggli, P.; Scott, A.; Yoder, R.; /Manhattan Coll., Riverdale

    2008-02-06

    The first phase of an experiment to study the performance of dielectric Cerenkov wakefield accelerating structures at extremely high gradients in the GV/m range has been completed. This experiment takes advantage of the unique SLAC FFTB electron beam and its demonstrated ultra-short pulse lengths and high currents (e.g., {sigma}{sub z} = 20 {micro}m at Q = 3 nC). The FFTB electron beam has been successfully focused down and sent through varying lengths of fused silica capillary tubing with two different sizes: ID = 200 {micro}m/OD = 325 {micro}m and ID = 100 {micro}m/OD = 325 {micro}m. The pulse length of the electron beam was varied in the range 20 {micro}m < {sigma}{sub z} < 100 {micro}m which produced a range of electric fields between 2 and 20 GV/m at the inner surface of the dielectric tubes. We observed a sharp increase in optical emissions from the capillaries in the middle part of this surface field range which we believe indicates the transition between sustainable field levels and breakdown. If this initial interpretation is correct, the surfaced fields that were sustained equate to on axis accelerating field of several GV/m. In future experiments we plan to collect and measure coherent Cerenkov radiation emitted from the capillary tube to gain more information about the strength of the accelerating fields.

  12. Experiments and simulation of high current operation at CEBAF

    SciTech Connect

    Merminga, L.; Crawford, K.; Delayen, J.R.; Doolittle, L.; Hovater, C.; Kazimi, R.; Krafft, G.; Reece, C.; Simrock, S.; Tiefenback, M.; Wang, D.X.

    1996-07-01

    The superconducting rf, cw electron accelerator at CEBAF has achieved the design energy of 4 GeV using 5-pass recirculation through a pair of 400 MeV linacs. Stable beam current of 35 {mu}A has been delivered to the Experimental Hall C. The total beam current that has been recirculated so far is 248 {mu}A. Measurements of the performance of the rf control system have been made in both pulsed and cw mode, and a numerical model has been developed which describes the beam-cavity interaction, includes a realistic representation of low level controls, klystron characteristics and microphonic noise. Experimental data and simulation results on transient beam loading, klystron saturation, a new technique for cavity phasing, and heavy beam loading tests are described; in conclusion, an outlook on full current operation is presented.

  13. Accelerating the connection between experiments and models: The FACE-MDS experience

    NASA Astrophysics Data System (ADS)

    Norby, R. J.; Medlyn, B. E.; De Kauwe, M. G.; Zaehle, S.; Walker, A. P.

    2014-12-01

    The mandate is clear for improving communication between models and experiments to better evaluate terrestrial responses to atmospheric and climatic change. Unfortunately, progress in linking experimental and modeling approaches has been slow and sometimes frustrating. Recent successes in linking results from the Duke and Oak Ridge free-air CO2 enrichment (FACE) experiments with ecosystem and land surface models - the FACE Model-Data Synthesis (FACE-MDS) project - came only after a period of slow progress, but the experience points the way to future model-experiment interactions. As the FACE experiments were approaching their termination, the FACE research community made an explicit attempt to work together with the modeling community to synthesize and deliver experimental data to benchmark models and to use models to supply appropriate context for the experimental results. Initial problems that impeded progress were: measurement protocols were not consistent across different experiments; data were not well organized for model input; and parameterizing and spinning up models that were not designed for simulating a specific site was difficult. Once these problems were worked out, the FACE-MDS project has been very successful in using data from the Duke and ORNL FACE experiment to test critical assumptions in the models. The project showed, for example, that the stomatal conductance model most widely used in models was supported by experimental data, but models did not capture important responses such as increased leaf mass per unit area in elevated CO2, and did not appropriately represent foliar nitrogen allocation. We now have an opportunity to learn from this experience. New FACE experiments that have recently been initiated, or are about to be initiated, include a eucalyptus forest in Australia; the AmazonFACE experiment in a primary, tropical forest in Brazil; and a mature oak woodland in England. Cross-site science questions are being developed that will have a

  14. Telescience operations with the solar array module plasma interaction experiment

    NASA Technical Reports Server (NTRS)

    Wald, Lawrence W.; Bibyk, Irene K.

    1995-01-01

    The Solar Array Module Plasma Interactions Experiment (SAMPIE) is a flight experiment that flew on the Space Shuttle Columbia (STS-62) in March 1994, as part of the OAST-2 mission. The overall objective of SAMPIE was to determine the adverse environmental interactions within the space plasma of low earth orbit (LEO) on modern solar cells and space power system materials which are artificially biased to high positive and negative direct current (DC) voltages. The two environmental interactions of interest included high voltage arcing from the samples to the space plasma and parasitic current losses. High voltage arcing can cause physical damage to power system materials and shorten expected hardware life. parasitic current losses can reduce power system efficiency because electric currents generated in a power system drain into the surrounding plasma via parasitic resistance. The flight electronics included two programmable high voltage DC power supplies to bias the experiment samples, instruments to measure the surrounding plasma environment in the STS cargo bay, and the on-board data acquisition system (DAS). The DAS provided in-flight experiment control, data storage, and communications through the Goddard Space Flight Center (GSFC) Hitchhiker flight avionics to the GSFC Payload Operations Control Center (POCC). The DAS and the SAMPIE POCC computer systems were designed for telescience operations; this paper will focus on the experiences of the SAMPIE team regarding telescience development and operations from the GSFC POCC during STS-62. The SAMPIE conceptual development, hardware design, and system verification testing were accomplished at the NASA Lewis Research Center (LeRC). SAMPIE was developed under the In-Space Technology Experiment Program (IN-STEP), which sponsors NASA, industry, and university flight experiments designed to enable and enhance space flight technology. The IN-STEP Program is sponsored by the Office of Space Access and Technology (OSAT).

  15. Telescience operations with the solar array module plasma interaction experiment

    SciTech Connect

    Wald, L.W.; Bibyk, I.K.

    1995-09-01

    The Solar Array Module Plasma Interactions Experiment (SAMPIE) is a flight experiment that flew on the Space Shuttle Columbia (STS-62) in March 1994, as part of the OAST-2 mission. The overall objective of SAMPIE was to determine the adverse environmental interactions within the space plasma of low earth orbit (LEO) on modern solar cells and space power system materials which are artificially biased to high positive and negative direct current (DC) voltages. The two environmental interactions of interest included high voltage arcing from the samples to the space plasma and parasitic current losses. High voltage arcing can cause physical damage to power system materials and shorten expected hardware life. Parasitic current losses can reduce power system efficiency because electric currents generated in a power system drain into the surrounding plasma via parasitic resistance. The flight electronics included two programmable high voltage DC power supplies to bias the experiment samples, instruments to measure the surrounding plasma environment in the STS cargo bay, and the on-board data acquisition system (DAS). The DAS provided in-flight experiment control, data storage, and communications through the Goddard Space Flight Center (GSFC) Hitchhiker flight avionics to the GSFC Payload Operations Control Center (POCC). The DAS and the SAMPIE POCC computer systems were designed for telescience operations; this paper will focus on the experiences of the SAMPIE team regarding telescience development and operations from the GSFC POCC during STS-62. The SAMPIE conceptual development, hardware design, and system verification testing were accomplished at the NASA Lewis Research Center (LeRC). SAMPIE was developed under the In-Space Technology Experiment Program (IN-STEP), which sponsors NASA, industry, and university flight experiments designed to enable and enhance space flight technology.

  16. Initial Physics Operation of the National Spherical Torus Experiment- Upgrade

    NASA Astrophysics Data System (ADS)

    Mueller, Dennis; NSTX-U Team

    2015-11-01

    The National Spherical Torus Experiment Upgrade (NSTX-U) is an experiment designed to study the physics of Spherical Torus (ST) at about twice the toroidal field and neutral beam injection (NBI) power as NSTX for 5 s. at full parameters. In its initial operational period NSTX-U will limit operation to BT <= .75 T but the full complement of 6 neutral beam (NB) sources will be available. Three NB sources added during the upgrade inject more tangentially and will be essential to investigate the physics of neutral beam current drive. In NSTX-U, use of a digital real-time plasma control system and the application of wall conditioning techniques will be used to achieve routine operation with good confinement. The wall conditioning techniques include bakeout to over 300°C, helium glow discharge cleaning, boronization of the plasma facing surfaces using deuterated trimethylboron gas in a helium glow discharge and lithium evaporation onto the walls. Auxiliary heating by up to 6 MW of High Harmonic Fast Waves will be available. The operational experience during the plasma commissioning phase will be discussed. Work Supported by U.S.D.O.E. Contract No. DE-AC02-09CH11466.

  17. Informed Practice: Students' Clinical Experiences in the Undergraduate Phase of an Accelerated Physician Assistant Program.

    PubMed

    Dereczyk, Amy; DeWitt, Rachel

    2016-06-01

    This qualitative study explored the clinical experiences of students in an accelerated physician assistant (PA) program. The participants were either certified nursing assistants (CNAs) or emergency medical technicians-basic (EMTs-B). The study was designed to elicit (1) how the participants perceived their older patients and (2) how the participants' experiences might affect their own future communications, bedside manner, and clinical preparedness as PAs. This study used a focus group to explore students' clinical experiences before the graduate phase of their accelerated PA program. Five female and 2 male PA students (N = 7) participated in the study. All participants were 23 years old and worked as either a CNA or an EMT-B. Results fell into 2 basic themes: informing practice and forming relationships. Regarding the first theme, participants felt that their experience as entry-level health care providers allowed them to improve their communication skills and bedside manner and to provide greater comfort to patients. Regarding the second theme, participants gained appreciation for older people and began to recognize the knowledge deficits and learning needs of their patients. The results suggested that a student's clinical experience as a CNA or an EMT-B before entering a PA program has a positive effect on the student's personal and professional development. The participants acquired greater appreciation and respect for older patients and members of the health care team. PMID:27123599

  18. Lattice design of the integrable optics test accelerator and optical stochastic cooling experiment at Fermilab

    SciTech Connect

    Kafka, Gene

    2015-05-01

    The Integrable Optics Test Accelerator (IOTA) storage ring at Fermilab will serve as the backbone for a broad spectrum of Advanced Accelerator R&D (AARD) experiments, and as such, must be designed with signi cant exibility in mind, but without compromising cost e ciency. The nonlinear experiments at IOTA will include: achievement of a large nonlinear tune shift/spread without degradation of dynamic aperture; suppression of strong lattice resonances; study of stability of nonlinear systems to perturbations; and studies of di erent variants of nonlinear magnet design. The ring optics control has challenging requirements that reach or exceed the present state of the art. The development of a complete self-consistent design of the IOTA ring optics, meeting the demands of all planned AARD experiments, is presented. Of particular interest are the precise control for nonlinear integrable optics experiments and the transverse-to-longitudinal coupling and phase stability for the Optical Stochastic Cooling Experiment (OSC). Since the beam time-of- ight must be tightly controlled in the OSC section, studies of second order corrections in this section are presented.

  19. Lattice design of the integrable optics test accelerator and optical stochastic cooling experiment at Fermilab

    NASA Astrophysics Data System (ADS)

    Kafka, Gene

    The Integrable Optics Test Accelerator (IOTA) storage ring at Fermilab will serve as the backbone for a broad spectrum of Advanced Accelerator R&D (AARD) experiments, and as such, must be designed with significant flexibility in mind, but without compromising cost efficiency. The nonlinear experiments at IOTA will include: achievement of a large nonlinear tune shift/spread without degradation of dynamic aperture; suppression of strong lattice resonances; study of stability of nonlinear systems to perturbations; and studies of different variants of nonlinear magnet design. The ring optics control has challenging requirements that reach or exceed the present state of the art. The development of a complete self-consistent design of the IOTA ring optics, meeting the demands of all planned AARD experiments, is presented. Of particular interest are the precise control for nonlinear integrable optics experiments and the transverse-to-longitudinal coupling and phase stability for the Optical Stochastic Cooling Experiment (OSC). Since the beam time-of-flight must be tightly controlled in the OSC section, studies of second order corrections in this section are presented.

  20. Ion accelerator system mounting design and operating characteristics for a 5 kW 30-cm xenon ion engine

    NASA Technical Reports Server (NTRS)

    Aston, Graeme; Brophy, John R.

    1987-01-01

    Results from a series of experiments to determine the effect of accelerator grid mount geometry on the performance of the J-series ion optics assembly are described. Three mounting schemes, two flexible and one rigid, are compared for their relative ion extraction capability over a range of total accelerating voltages. The largest ion beam current, for the maximum total voltage investigated, is shown to occur using one of the flexible grid mounting geometries. However, at lower total voltages and reduced engine input power levels, the original rigid J-series ion optics accelerator grid mounts result in marginally better grid system performance at the same cold interelectrode gap.

  1. Raccoon Mountain pumped-storage plant: Ten years operating experience

    SciTech Connect

    Adkins, F.E.

    1987-09-01

    Operational experience at the 1 530 MW Raccoon Mountain underground pumped-storage plant can be relevant to other large hydro facilities. A number of unusual features were incorporated and individual unit size was only recently overtaken elsewhere. Direct water cooling of rotor and stator winding has been successfully applied to salient pole machines. A number of problems, including difficulties with oil-filled 161 kV current transformers, and some mechanical aspects, are reported. Designed for remote supervisory control, the plant has required closer attention. Operating statistics are included.

  2. The latest results from ELM-simulation experiments in plasma accelerators

    NASA Astrophysics Data System (ADS)

    Garkusha, I. E.; Arkhipov, N. I.; Klimov, N. S.; Makhlaj, V. A.; Safronov, V. M.; Landman, I.; Tereshin, V. I.

    2009-12-01

    Recent results of ELM-simulation experiments with quasi-stationary plasma accelerators (QSPAs) Kh-50 (Kharkov, Ukraine) and QSPA-T (Troitsk, Russia) as well as experiments in the pulsed plasma gun MK-200UG (Troitsk, Russia) are discussed. Primary attention in Troitsk experiments has been focused on investigating the carbon-fibre composite (CFC) and tungsten erosion mechanisms, their onset conditions and the contribution of various erosion mechanisms (including droplet splashing) to the resultant surface damage at varying plasma heat flux. The obtained results are used for validating the numerical codes PEGASUS and MEMOS developed in FZK. Crack patterns and residual stresses in tungsten targets under repetitive edge localized mode (ELM)-like plasma pulses are studied in simulation experiments with QSPA Kh-50. Statistical processing of the experimental results on crack patterns after different numbers of QSPA Kh-50 exposures as well as those on the dependence of cracking on the heat load and surface temperature is performed.

  3. Operations summary for the convection and moisture experiment (CAMEX)

    NASA Technical Reports Server (NTRS)

    Griffin, V. L.; Guillory, A. R.; Susko, M.; Arnold, J. E.

    1994-01-01

    During the fall of 1993, NASA sponsored a field program called the Convection and Moisture Experiment (CAMEX) at Wallops Island, Virginia. CAMEX was a multidisciplinary experiment design to measure the three dimensional moisture fields over Wallops Island and to characterize the multifrequency radiometric signature of tropical convection over the Gulf Stream and southeastern Atlantic Ocean. This document summarizes the daily CAMEX activities, including ground and aircraft (NASA ER-2) operations, and includes 'quick-look' summaries of data acquisition along with data examples provided by the various CAMEX PI's.

  4. X-Band Photonic Band-Gap Accelerator Structure Breakdown Experiment

    SciTech Connect

    Marsh, Roark A.; Shapiro, Michael A.; Temkin, Richard J.; Dolgashev, Valery A.; Laurent, Lisa L.; Lewandowski, James R.; Yeremian, A.Dian; Tantawi, Sami G.; /SLAC

    2012-06-11

    In order to understand the performance of photonic band-gap (PBG) structures under realistic high gradient, high power, high repetition rate operation, a PBG accelerator structure was designed and tested at X band (11.424 GHz). The structure consisted of a single test cell with matching cells before and after the structure. The design followed principles previously established in testing a series of conventional pillbox structures. The PBG structure was tested at an accelerating gradient of 65 MV/m yielding a breakdown rate of two breakdowns per hour at 60 Hz. An accelerating gradient above 110 MV/m was demonstrated at a higher breakdown rate. Significant pulsed heating occurred on the surface of the inner rods of the PBG structure, with a temperature rise of 85 K estimated when operating in 100 ns pulses at a gradient of 100 MV/m and a surface magnetic field of 890 kA/m. A temperature rise of up to 250 K was estimated for some shots. The iris surfaces, the location of peak electric field, surprisingly had no damage, but the inner rods, the location of the peak magnetic fields and a large temperature rise, had significant damage. Breakdown in accelerator structures is generally understood in terms of electric field effects. These PBG structure results highlight the unexpected role of magnetic fields in breakdown. The hypothesis is presented that the moderate level electric field on the inner rods, about 14 MV/m, is enhanced at small tips and projections caused by pulsed heating, leading to breakdown. Future PBG structures should be built to minimize pulsed surface heating and temperature rise.

  5. STS-40 orbital acceleration research experiment flight results during a typical sleep period

    NASA Technical Reports Server (NTRS)

    Blanchard, R. C.; Nicholson, J. Y.; Ritter, J. R.

    1992-01-01

    The Orbital Acceleration Research Experiment (OARE), an electrostatic accelerometer package with complete on-orbit calibration capabilities, was flown for the first time aboard the Space Shuttle on STS-40. This is also the first time an accelerometer package with nano-g sensitivity and a calibration facility has flown aboard the Space Shuttle. The instrument is designed to measure and record the Space Shuttle aerodynamic acceleration environment from the free molecule flow regime through the rarified flow transition into the hypersonic continuum regime. Because of its sensitivity, the OARE instrument defects aerodynamic behavior of the Space Shuttle while in low-earth orbit. A 2-hour orbital time period on day seven of the mission, when the crew was asleep and other spacecraft activities were at a minimum, was examined. During the flight, a 'trimmed-mean' filter was used to produce high quality, low frequency data which was successfully stored aboard the Space Shuttle in the OARE data storage system. Initial review of the data indicated that, although the expected precision was achieved, some equipment problems occurred resulting in uncertain accuracy. An acceleration model which includes aerodynamic, gravity-gradient, and rotational effects was constructed and compared with flight data. Examination of the model with the flight data shows the instrument to be sensitive to all major expected low frequency acceleration phenomena; however, some erratic instrument bias behavior persists in two axes. In these axes, the OARE data can be made to match a comprehensive atmospheric-aerodynamic model by making bias adjustments and slight linear corrections for drift. The other axis does not exhibit these difficulties and gives good agreement with the acceleration model.

  6. The National Flood Interoperability Experiment: Bridging Resesarch and Operations

    NASA Astrophysics Data System (ADS)

    Salas, F. R.

    2015-12-01

    The National Weather Service's new National Water Center, located on the University of Alabama campus in Tuscaloosa, will become the nation's hub for comprehensive water resources forecasting. In conjunction with its federal partners the US Geological Survey, Army Corps of Engineers and Federal Emergency Management Agency, the National Weather Service will operationally support both short term flood prediction and long term seasonal forecasting of water resource conditions. By summer 2016, the National Water Center will begin evaluating four streamflow data products at the scale of the NHDPlus river reaches (approximately 2.67 million). In preparation for the release of these products, from September 2014 to August 2015, the National Weather Service partnered with the Consortium of Universities for the Advancement of Hydrologic Science, Inc. to support the National Flood Interoperability Experiment which included a seven week in-residence Summer Institute in Tuscaloosa for university students interested in learning about operational hydrology and flood forecasting. As part of the experiment, 15 hour forecasts from the operational High Resolution Rapid Refresh atmospheric model were used to drive a three kilometer Noah-MP land surface model loosely coupled to a RAPID river routing model operating on the NHDPlus dataset. This workflow was run every three hours during the Summer Institute and the results were made available to those engaged to pursue a range of research topics focused on flood forecasting (e.g. reservoir operations, ensemble forecasting, probabilistic flood inundation mapping, rainfall product evaluation etc.) Although the National Flood Interoperability Experiment was finite in length, it provided a platform through which the academic community could engage federal agencies and vice versa to narrow the gap between research and operations and demonstrate how state of the art research infrastructure, models, services, datasets etc. could be utilized

  7. Experiences with operations and autonomy of the Mars Pathfinder Microrover.

    NASA Astrophysics Data System (ADS)

    Mishkin, A. H.; Morrison, J. C.; Nguyen, T. T.; Stone, H. W.; Cooper, B. K.; Wilcox, B. H.

    The Microrover Flight Experiment (MFEX) is a NASA OACT (Office of Advanced Concepts and Technology) flight experiment which, integrated with the Mars Pathfinder (MPF) lander and spacecraft system, landed on Mars on July 4, 1997. In the succeeding 30 sols (1 sol = 1 Martian day), the Sojourner microrover accomplished all of its primary and extended mission objectives. After completion of the originally planned extended mission, MFEX continued to conduct a series of technology experiments, deploy its alpha proton X-ray spectrometer (APXS) on rocks and soil, and image both terrain features and the lander. This mission was conducted under the constraints of a once-per-sol opportunity for command and telemetry transmissions between the lander and Earth operators. As such, the MFEX rover was required to carry out its mission, including terrain navigation and contingency response, under supervised autonomous control. For example, goal locations were specified daily by human operators; the rover then safely traversed to these locations. During traverses, the rover autonomously detected and avoided rock, slope, and drop-off hazards, changing its path as needed before turning back towards its goal. This capability to operate in an unmodeled environment, choosing actions in response to sensor input to accomplish requested objectives, is unique among robotic space missions to date.

  8. Operator experiences on working in screen-based control rooms

    SciTech Connect

    Salo, L.; Laarni, J.; Savioja, P.

    2006-07-01

    This paper introduces the results of two interview studies carried out in Finland in four conventional power plants and one nuclear power plant. The aim of the studies was to gather data on user experiences on the effects of control room modernization and digital control room technology on operator work Since the number of completed digitalization projects in nuclear power plants is small supplementary information was gathered by interviewing operators in conventional power plants. Our results suggest that even though the modernization processes have been success stories, they have created new challenges for operator personnel. Examples of these challenges are increased requirements for competence and collaboration, problems in trust calibration and development of awareness of the process state. Some major differences in the digitalization of human-system interfaces between conventional and nuclear power plants were discussed. (authors)

  9. Five years operating experience at the Fast Flux Test Facility

    SciTech Connect

    Baumhardt, R. J.; Bechtold, R. A.

    1987-04-01

    The Fast Flux Test Facility (FFTF) is a 400 Mw(t), loop-type, sodium-cooled, fast neutron reactor. It is operated by the Westinghouse Hanford Company for the United States Department of Energy at Richland, Washington. The FFTF is a multipurpose test reactor used to irradiate fuels and materials for programs such as Liquid Metal Reactor (LMR) research, fusion research, space power systems, isotope production and international research. FFTF is also used for testing concepts to be used in Advanced Reactors which will be designed to maximize passive safety features and not require complex shutdown systems to assure safe shutdown and heat removal. The FFTF also provides experience in the operation and maintenance of a reactor having prototypic components and systems typical of large LMR (LMFBR) power plants. The 5 year operational performance of the FFTF reactor is discussed in this report. 6 refs., 10 figs., 2 tabs.

  10. Wabash River coal gasification repowering project -- first year operation experience

    SciTech Connect

    Troxclair, E.J.; Stultz, J.

    1997-12-31

    The Wabash River Coal Gasification Repowering Project (WRCGRP), a joint venture between Destec Energy, Inc. and PSI Energy, Inc., began commercial operation in November of 1995. The Project, selected by the United States Department of Energy (DOE) under the Clean Coal Program (Round IV) represents the largest operating coal gasification combined cycle plant in the world. This Demonstration Project has allowed PSI Energy to repower a 1950`s vintage steam turbine and install a new syngas fired combustion turbine to provide 262 MW (net) of electricity in a clean, efficient manner in a commercial utility setting while utilizing locally mined high sulfur Indiana bituminous coal. In doing so, the Project is also demonstrating some novel technology while advancing the commercialization of integrated coal gasification combined cycle technology. This paper discusses the first year operation experience of the Wabash Project, focusing on the progress towards achievement of the demonstration objectives.

  11. Beryllium liner implosion experiments on the Z accelerator in preparation for magnetized liner inertial fusiona)

    NASA Astrophysics Data System (ADS)

    McBride, R. D.; Martin, M. R.; Lemke, R. W.; Greenly, J. B.; Jennings, C. A.; Rovang, D. C.; Sinars, D. B.; Cuneo, M. E.; Herrmann, M. C.; Slutz, S. A.; Nakhleh, C. W.; Ryutov, D. D.; Davis, J.-P.; Flicker, D. G.; Blue, B. E.; Tomlinson, K.; Schroen, D.; Stamm, R. M.; Smith, G. E.; Moore, J. K.; Rogers, T. J.; Robertson, G. K.; Kamm, R. J.; Smith, I. C.; Savage, M.; Stygar, W. A.; Rochau, G. A.; Jones, M.; Lopez, M. R.; Porter, J. L.; Matzen, M. K.

    2013-05-01

    Multiple experimental campaigns have been executed to study the implosions of initially solid beryllium (Be) liners (tubes) on the Z pulsed-power accelerator. The implosions were driven by current pulses that rose from 0 to 20 MA in either 100 or 200 ns (200 ns for pulse shaping experiments). These studies were conducted in support of the recently proposed Magnetized Liner Inertial Fusion concept [Slutz et al., Phys. Plasmas 17, 056303 (2010)], as well as for exploring novel equation-of-state measurement techniques. The experiments used thick-walled liners that had an aspect ratio (initial outer radius divided by initial wall thickness) of either 3.2, 4, or 6. From these studies, we present three new primary results. First, we present radiographic images of imploding Be liners, where each liner contained a thin aluminum sleeve for enhancing the contrast and visibility of the liner's inner surface in the images. These images allow us to assess the stability of the liner's inner surface more accurately and more directly than was previously possible. Second, we present radiographic images taken early in the implosion (prior to any motion of the liner's inner surface) of a shockwave propagating radially inward through the liner wall. Radial mass density profiles from these shock compression experiments are contrasted with profiles from experiments where the Z accelerator's pulse shaping capabilities were used to achieve shockless ("quasi-isentropic") liner compression. Third, we present "micro-Ḃ" measurements of azimuthal magnetic field penetration into the initially vacuum-filled interior of a shocked liner. Our measurements and simulations reveal that the penetration commences shortly after the shockwave breaks out from the liner's inner surface. The field then accelerates this low-density "precursor" plasma to the axis of symmetry.

  12. Beryllium liner implosion experiments on the Z accelerator in preparation for magnetized liner inertial fusion

    SciTech Connect

    McBride, R. D.; Martin, M. R.; Lemke, R. W.; Jennings, C. A.; Rovang, D. C.; Sinars, D. B.; Cuneo, M. E.; Herrmann, M. C.; Slutz, S. A.; Nakhleh, C. W.; Davis, J.-P.; Flicker, D. G.; Rogers, T. J.; Robertson, G. K.; Kamm, R. J.; Smith, I. C.; Savage, M.; Stygar, W. A.; Rochau, G. A.; Jones, M.; and others

    2013-05-15

    Multiple experimental campaigns have been executed to study the implosions of initially solid beryllium (Be) liners (tubes) on the Z pulsed-power accelerator. The implosions were driven by current pulses that rose from 0 to 20 MA in either 100 or 200 ns (200 ns for pulse shaping experiments). These studies were conducted in support of the recently proposed Magnetized Liner Inertial Fusion concept [Slutz et al., Phys. Plasmas 17, 056303 (2010)], as well as for exploring novel equation-of-state measurement techniques. The experiments used thick-walled liners that had an aspect ratio (initial outer radius divided by initial wall thickness) of either 3.2, 4, or 6. From these studies, we present three new primary results. First, we present radiographic images of imploding Be liners, where each liner contained a thin aluminum sleeve for enhancing the contrast and visibility of the liner's inner surface in the images. These images allow us to assess the stability of the liner's inner surface more accurately and more directly than was previously possible. Second, we present radiographic images taken early in the implosion (prior to any motion of the liner's inner surface) of a shockwave propagating radially inward through the liner wall. Radial mass density profiles from these shock compression experiments are contrasted with profiles from experiments where the Z accelerator's pulse shaping capabilities were used to achieve shockless (“quasi-isentropic”) liner compression. Third, we present “micro-B-dot ” measurements of azimuthal magnetic field penetration into the initially vacuum-filled interior of a shocked liner. Our measurements and simulations reveal that the penetration commences shortly after the shockwave breaks out from the liner's inner surface. The field then accelerates this low-density “precursor” plasma to the axis of symmetry.

  13. Operation Heli-STAR - Atlanta Communications Experiment (ACE). Volume 9

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Operation Heli-STAR (Helicopter Short-Haul Transportation and Aviation Research) was established and operated in Atlanta, Georgia, during the period of the 1996 Centennial Olympic Games. Heli-STAR had three major thrusts: (1) the establishment and operation of a helicopter-based cargo transportation system, (2) the management of low-altitude air traffic in the airspace of an urban area, and (3) the collection and analysis of research and development data associated with items 1 and 2. Heli-STAR was a cooperative industry/government program that included parcel package shippers and couriers in the Atlanta area, the helicopter industry, aviation electronics manufacturers, the Federal Aviation Administration (FAA), the National Aeronautics and Space Administration (NASA), and support contractors. Several detailed reports have been produced as a result of Operation Heli-STAR. These include four reports on acoustic measurements and associated analyses, and reports on the Heli-STAR tracking data including the data processing and retrieval system, the Heli-STAR cargo simulation, and the community response system. In addition, NASA's Advanced General Aviation Transport Experiments (AGATE) program has produced a report describing the Atlanta Communications Experiment (ACE) which produced the avionics and ground equipment using automatic dependent surveillance-broadcast (ADS-B) technology. This latter report is restricted to organizations belonging to NASA's AGATE industry consortium. A complete list of these reports is shown on the following page.

  14. Design and fabrication of plasma accelerator for space micro-debris simulation and preliminary experiment

    NASA Astrophysics Data System (ADS)

    Han, J.; Zhang, Z.; Huang, J.; Li, X.; Chen, Z.; Quan, R.

    A simulation facility for hypervelocity impact of space micro-debris is designed and fabricated Just after the assembly of the facility some preliminary debugging experiments have conducted A plasma accelerator is the core component of the facility which composed of a coaxial discharge electrode an electromagnetic compressing coil and a nozzle The coaxial electrode is discharged synchronously by pulse injected gas from a delicate fabricated electromagnetic valve and pulse voltage from a capacitance bank The time periods for the pulse gas valve to turn on and to feed gas are 400 and 900 microseconds respectively As to the capacitance bank the maximum capacity is 512 mu F and can be charged as high as 30kV Therefore the maximum energy storage for the capacitance and discharge is 230KJ A custom designed control circuit ignites the pulse valve and discharge switch in turn Then a block of plasma is produced and accelerated into the electromagnetic coil where the plasma is compressed denser Eventually a plasma flow with high pressure and temperature is sprayed out the nozzle which pushes a cluster of micro-particles attached closely to the nozzle exit to hypervelocity During the preliminary debugging experiment 128 mu F capacitance is charged to 15kV and 400kA discharge current is generated then glass spheres with 100 mu m diameter is accelerated to 4 3km s Now the debug for the facility is still in progress in the near future it can accelerate micro-particles to higher velocity

  15. Measurements of fusion neutrons from Magnetized Liner Inertial Fusion Experiments on the Z accelerator

    NASA Astrophysics Data System (ADS)

    Hahn, K. D.; Chandler, G. A.; Ruiz, C. L.; Gomez, M. R.; Slutz, S. A.; Sefkow, A. B.; Sinars, D. B.; Hansen, S. B.; Knapp, P. F.; Schmit, P. F.; Harding, E. C.; Awe, T. J.; Torres, J. A.; Jones, B.; Bur, J. A.; Cooper, G. W.; Styron, J. D.; Glebov, V. Yu.

    2015-11-01

    Strong evidence of thermonuclear neutron production has been observed during Magnetized Liner Inertial Fusion (MagLIF) experiments on the Z accelerator. So far, these experiments have utilized deuterium fuel and produced primary DD fusion neutron yields up to 2e12 with electron and ion stagnation temperatures in the 2-3 keV range. We present MagLIF neutron measurements and compare to other data and implosion simulations. In addition to primary DD and secondary DT yields and ion temperatures, other complex physics regarding the degree of fuel magnetization and liner density are elucidated by the neutron measurements. Neutron diagnostic development for deuterium and future deuterium-tritium fuel experiments are also discussed. Sandia is sponsored by the U.S. DOE's NNSA under contract DE-AC04-94AL85000.

  16. An Ultra-High Gradient Cherenkov Wakefield Acceleration Experiment at SLAC FFTB

    SciTech Connect

    Rosenzweig, J.B.; Hoover, S.; Hogan, M.J.; Muggli, P.; Thompson, M.; Travish, G.; Yoder, R.; /UCLA /SLAC /Southern California U.

    2005-08-02

    The creation of ultra-high current, ultra-short pulse beams Q=3 nC, {sigma}{sub z} = 20{micro}m at the SLAC FFTB has opened the way for very high gradient plasma wakefield acceleration experiments. We study here the use of these beams in a proposed Cherenkov wakefield experiment, where one may excite electromagnetic wakes in a simple dielectric tube with inner diameter of few 100 microns that exceed the GV/m level. We discuss the scaling of the fields with design geometric design parameters, and choice of dielectric. We also examine measurable aspects of the experiment, such as the total coherent Cerenkov radiation energy one may collect, and the expected aspects of dielectric breakdown at high fields.

  17. CEBAF accelerator achievements

    SciTech Connect

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

    2011-06-01

    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.

  18. DIII-D safety procedures and operational experience

    NASA Astrophysics Data System (ADS)

    Petersen, Peter I.; Savercool, Richard L.; Taylor, Peter L.

    1989-06-01

    The DIII-D research tokamak, which has near reactor dimensions, has been operating for approximately ten years. The hazards at the facility include high voltages, high currents, cryogenics, radiation, and normal industrial hazards. Procedures have been developed for operating the device, minimizing both the hazards to personnel and the damage caused by equipment failures, and for logging of failures. The machine and the neutral beamlines have been operated in hydrogen and are now starting operation in deuterium to expand the machine capabilities to reactor relevant regimes. Deuterium operation creates a significant amount of neutrons and therefore a neutron shield is being built around the machine area to reduce personnel radiation to As Low As Reasonably Achievable (ALARA) and to keep radiation at the site boundary at or below a limit of 20 mrem per calendar year. Gamma radiation shielding walls have been in place since the initial machine construction. The safety procedures for the DIII-D facility will be outlined and the accident experience will be discussed together with the neutron radiation monitoring program being developed.

  19. From experiment to design -- Fault characterization and detection in parallel computer systems using computational accelerators

    NASA Astrophysics Data System (ADS)

    Yim, Keun Soo

    This dissertation summarizes experimental validation and co-design studies conducted to optimize the fault detection capabilities and overheads in hybrid computer systems (e.g., using CPUs and Graphics Processing Units, or GPUs), and consequently to improve the scalability of parallel computer systems using computational accelerators. The experimental validation studies were conducted to help us understand the failure characteristics of CPU-GPU hybrid computer systems under various types of hardware faults. The main characterization targets were faults that are difficult to detect and/or recover from, e.g., faults that cause long latency failures (Ch. 3), faults in dynamically allocated resources (Ch. 4), faults in GPUs (Ch. 5), faults in MPI programs (Ch. 6), and microarchitecture-level faults with specific timing features (Ch. 7). The co-design studies were based on the characterization results. One of the co-designed systems has a set of source-to-source translators that customize and strategically place error detectors in the source code of target GPU programs (Ch. 5). Another co-designed system uses an extension card to learn the normal behavioral and semantic execution patterns of message-passing processes executing on CPUs, and to detect abnormal behaviors of those parallel processes (Ch. 6). The third co-designed system is a co-processor that has a set of new instructions in order to support software-implemented fault detection techniques (Ch. 7). The work described in this dissertation gains more importance because heterogeneous processors have become an essential component of state-of-the-art supercomputers. GPUs were used in three of the five fastest supercomputers that were operating in 2011. Our work included comprehensive fault characterization studies in CPU-GPU hybrid computers. In CPUs, we monitored the target systems for a long period of time after injecting faults (a temporally comprehensive experiment), and injected faults into various types of

  20. Characterization of the radiation environment at the UNLV accelerator facility during operation of the Varian M6 linac

    NASA Astrophysics Data System (ADS)

    Hodges, M.; Barzilov, A.; Chen, Y.; Lowe, D.

    2016-10-01

    The bremsstrahlung photon flux from the UNLV particle accelerator (Varian M6 model) was determined using MCNP5 code for 3 MeV and 6 MeV incident electrons. Human biological equivalent dose rates due to accelerator operation were evaluated using the photon flux with the flux-to-dose conversion factors. Dose rates were computed for the accelerator facility for M6 linac use under different operating conditions. The results showed that the use of collimators and linac internal shielding significantly reduced the dose rates throughout the facility. It was shown that the walls of the facility, in addition to the earthen berm enveloping the building, provide equivalent shielding to reduce dose rates outside to below the 2 mrem/h limit.

  1. Early Commissioning Experience and Future Plans for the 12 GeV Continuous Electron Beam Accelerator Facility

    SciTech Connect

    Spata, Michael F.

    2014-12-01

    Jefferson Lab has recently completed the accelerator portion of the 12 GeV Upgrade for the Continuous Electron Beam Accelerator Facility. All 52 SRF cryomodules have been commissioned and operated with beam. The initial beam transport goals of demonstrating 2.2 GeV per pass, greater than 6 GeV in 3 passes to an existing experimental facility and greater than 10 GeV in 5-1/2 passes have all been accomplished. These results along with future plans to commission the remaining beamlines and to increase the performance of the accelerator to achieve reliable, robust and efficient operations at 12 GeV are presented.

  2. Investigation of neutrino oscillations in the T2k long-baseline accelerator experiment

    SciTech Connect

    Izmaylov, A. O. Yershov, N. V.; Kudenko, Yu. G.; Matveev, V. A.; Mineev, O. V.; Musienko, Yu. V.; Khabibulliun, M. M.; Khotjantsev, A. N.; Shaykhiev, A. T.

    2012-02-15

    High-sensitivity searches for transitions of muon neutrinos to electron neutrinos are the main task of the T2K (Tokai-to-Kamioka) second-generation long-baseline accelerator neutrino experiment. The present article is devoted to describing basic principles of T2K, surveying experimental apparatuses that it includes, and considering in detail the muon-range detector (SMRD) designed and manufactured by a group of physicists from the Institute of Nuclear Research (Russian Academy of Sciences, Moscow). The results of the first measurements with a neutrino beam are presented, and plans for the near future are discussed.

  3. Turbulent Magnetohydrodynamic Acceleration Processes: Theory SSX Experiments and Connections to Space and Astrophysics

    SciTech Connect

    W Matthaeus; M Brown

    2006-07-15

    This is the final technical report for a funded program to provide theoretical support to the Swarthmore Spheromak Experiment. We examined mhd relaxation, reconnecton between two spheromaks, particle acceleration by these processes, and collisonless effects, e.g., Hall effect near the reconnection zone,. Throughout the project, applications to space plasma physics and astrophysics were included. Towards the end ofthe project we were examining a more fully turbulent relaxation associated with unconstrained dynamics in SSX. We employed experimental, spacecraft observations, analytical and numerical methods.

  4. Vibration isolation technology: Sensitivity of selected classes of space experiments to residual accelerations

    NASA Technical Reports Server (NTRS)

    Alexander, J. Iwan D.; Zhang, Y. Q.; Adebiyi, Adebimpe

    1989-01-01

    Progress performed on each task is described. Order of magnitude analyses related to liquid zone sensitivity and thermo-capillary flow sensitivity are covered. Progress with numerical models of the sensitivity of isothermal liquid zones is described. Progress towards a numerical model of coupled buoyancy-driven and thermo-capillary convection experiments is also described. Interaction with NASA personnel is covered. Results to date are summarized and they are discussed in terms of the predicted space station acceleration environment. Work planned for the second year is also discussed.

  5. The UCLA/SLAC Ultra-High Gradient Cerenkov Wakefield Accelerator Experiment

    SciTech Connect

    Thompson, M.C.; Badakov, H.; Rosenzweig, J.B.; Travish, G.; Hogan, M.; Ischebec, R.; Siemann, R.; Walz, D.; Scott, A.; Yoder, R.; /Manhattan Coll., Riverdale

    2006-01-25

    An experiment is planned to study the performance of dielectric Cerenkov wakefield accelerating structures at extremely high gradients in the GV/m range. This new UCLA/SLAC/USC collaboration will take advantage of the unique SLAC FFTB electron beam and its demonstrated ultra-short pulse lengths and high currents (e.g., {delta}{sub z} = 20 {micro}m at Q = 3 nC). The electron beam will be focused down and sent through varying lengths of fused silica capillary tubing with two different sizes: ID = 200 {micro}m/OD = 325 {micro}m and ID = 100 {micro}m/OD = 325 {micro}m. The pulse length of the electron beam will be varied in order to alter the accelerating gradient and probe the breakdown threshold of the dielectric structures. In addition to breakdown studies, we plan to collect and measure coherent Cerenkov radiation emitted from the capillary tube to gain information about the strength of the accelerating fields.

  6. The Software Engineering Laboratory: An operational software experience factory

    NASA Technical Reports Server (NTRS)

    Basili, Victor R.; Caldiera, Gianluigi; Mcgarry, Frank; Pajerski, Rose; Page, Gerald; Waligora, Sharon

    1992-01-01

    For 15 years, the Software Engineering Laboratory (SEL) has been carrying out studies and experiments for the purpose of understanding, assessing, and improving software and software processes within a production software development environment at NASA/GSFC. The SEL comprises three major organizations: (1) NASA/GSFC, Flight Dynamics Division; (2) University of Maryland, Department of Computer Science; and (3) Computer Sciences Corporation, Flight Dynamics Technology Group. These organizations have jointly carried out several hundred software studies, producing hundreds of reports, papers, and documents, all of which describe some aspect of the software engineering technology that was analyzed in the flight dynamics environment at NASA. The studies range from small, controlled experiments (such as analyzing the effectiveness of code reading versus that of functional testing) to large, multiple project studies (such as assessing the impacts of Ada on a production environment). The organization's driving goal is to improve the software process continually, so that sustained improvement may be observed in the resulting products. This paper discusses the SEL as a functioning example of an operational software experience factory and summarizes the characteristics of and major lessons learned from 15 years of SEL operations.

  7. Operational experiences of a commercial helicopter flown in a large metropolitan area

    NASA Technical Reports Server (NTRS)

    Dicarlo, D. J.

    1975-01-01

    A survey of commercial helicopter-operating experiences was conducted using a helicopter flight recorder in order to provide a basis for extending helicopter design and service-life criteria. These data are representative of 182 flight hours accumulated during 1414 flights comprised of the separate legs of the total route structure employed. The operating experiences are presented in terms of the time spent within different airspeed brackets, within the classifiable flight conditions of climb, en route, and descent, at various rates of climb and descent, and at different rotor rotational speeds. The results indicated that the helicopter spent a majority of the flight time at airspeeds either below 40 knots or above 100 knots. Rates of climb and descent were concentrated at values below 5.1 m/s (1000 ft/min) particularly for higher airspeeds. Normal acceleration experiences were low, both in the total number and peak value realized; however, an extremely large number of pitch angular-velocity experiences were noted. Rotor rotational speeds were normal with no occurrences above the upper red-line limit.

  8. Experimental characterization of a coaxial plasma accelerator for a colliding plasma experiment

    NASA Astrophysics Data System (ADS)

    Wiechula, J.; Hock, C.; Iberler, M.; Manegold, T.; Schönlein, A.; Jacoby, J.

    2015-04-01

    We report experimental results of a single coaxial plasma accelerator in preparation for a colliding plasma experiment. The utilized device consisted of a coaxial pair of electrodes, accelerating the plasma due to J ×B forces. A pulse forming network, composed of three capacitors connected in parallel, with a total capacitance of 27 μF was set up. A thyratron allowed to switch the maximum applied voltage of 9 kV. Under these conditions, the pulsed currents reached peak values of about 103 kA. The measurements were performed in a small vacuum chamber with a neutral-gas prefill at gas pressures between 10 Pa and 14 000 Pa. A gas mixture of ArH2 with 2.8% H2 served as the discharge medium. H2 was chosen in order to observe the broadening of the Hβ emission line and thus estimate the electron density. The electron density for a single plasma accelerator reached peak values on the order of 1016 cm-3 . Electrical parameters, inter alia inductance and resistance, were determined for the LCR circuit during the plasma acceleration as well as in a short circuit case. Depending on the applied voltage, the inductance and resistance reached values ranging from 194 nH to 216 nH and 13 mΩ to 23 mΩ, respectively. Furthermore, the plasma velocity was measured using a fast CCD camera. Plasma velocities of 2 km/s up to 17 km/s were observed, the magnitude being highly correlated with gas pressure and applied voltage.

  9. Experimental characterization of a coaxial plasma accelerator for a colliding plasma experiment

    SciTech Connect

    Wiechula, J.; Hock, C.; Iberler, M.; Manegold, T.; Schönlein, A.; Jacoby, J.

    2015-04-15

    We report experimental results of a single coaxial plasma accelerator in preparation for a colliding plasma experiment. The utilized device consisted of a coaxial pair of electrodes, accelerating the plasma due to J×B forces. A pulse forming network, composed of three capacitors connected in parallel, with a total capacitance of 27 μF was set up. A thyratron allowed to switch the maximum applied voltage of 9 kV. Under these conditions, the pulsed currents reached peak values of about 103 kA. The measurements were performed in a small vacuum chamber with a neutral-gas prefill at gas pressures between 10 Pa and 14 000 Pa. A gas mixture of ArH{sub 2} with 2.8% H{sub 2} served as the discharge medium. H{sub 2} was chosen in order to observe the broadening of the H{sub β} emission line and thus estimate the electron density. The electron density for a single plasma accelerator reached peak values on the order of 10{sup 16} cm{sup −3}. Electrical parameters, inter alia inductance and resistance, were determined for the LCR circuit during the plasma acceleration as well as in a short circuit case. Depending on the applied voltage, the inductance and resistance reached values ranging from 194 nH to 216 nH and 13 mΩ to 23 mΩ, respectively. Furthermore, the plasma velocity was measured using a fast CCD camera. Plasma velocities of 2 km/s up to 17 km/s were observed, the magnitude being highly correlated with gas pressure and applied voltage.

  10. Effects of Experiment Location and Orbiter Attitude on the Residual Acceleration On-Board STS-73 (USML-2)

    NASA Technical Reports Server (NTRS)

    Hakimzadeh, Roshanak; McPherson, Kevin M.; Matisak, Brian P.; Wagar, William O.

    1997-01-01

    A knowledge of the quasi-steady acceleration environment on the NASA Space Shuttle Orbiter is of particular importance for materials processing experiments which are limited by slow diffusive processes. The quasi-steady (less than 1 HZ) acceleration environment on STS-73 (USML-2) was measured using the Orbital Acceleration Research Experiment (OARE) accelerometer. One of the facilities flown on USML-2 was the Crystal Growth Furnace (CGF), which was used by several Principal Investigators (PIS) to grow crystals. In this paper the OARE data mapped to the sample melt location within this furnace is presented. The ratio of the axial to radial components of the quasi-steady acceleration at the melt site is presented. Effects of Orbiter attitude on the acceleration data is discussed.

  11. Simultaneous operation of two soft x-ray free-electron lasers driven by one linear accelerator

    DOE PAGESBeta

    Faatz, B.; Plönjes, E.; Ackermann, S.; Agababyan, A.; Asgekar, V.; Ayvazyan, V.; Baark, S.; Baboi, N.; Balandin, V.; Bargen, N. von; et al

    2016-06-20

    Extreme-ultraviolet to x-ray free-electron lasers (FELs) in operation for scientific applications are up to now single-user facilities. While most FELs generate around 100 photon pulses per second, FLASH at DESY can deliver almost two orders of magnitude more pulses in this time span due to its superconducting accelerator technology. This makes the facility a prime candidate to realize the next step in FELs—dividing the electron pulse trains into several FEL lines and delivering photon pulses to several users at the same time. Hence, FLASH has been extended with a second undulator line and self-amplified spontaneous emission (SASE) is demonstrated inmore » both FELs simultaneously. Here, FLASH can now deliver MHz pulse trains to two user experiments in parallel with individually selected photon beam characteristics. First results of the capabilities of this extension are shown with emphasis on independent variation of wavelength, repetition rate, and photon pulse length.« less

  12. Nuclear unit operating experience: 1985-1986 update: Final report

    SciTech Connect

    LeShay, D.W.; Koppe, R.H.; Olson, E.A.J.

    1987-12-01

    This report presents results of a project conducted by the S.M. Stoller Corporation for EPRI. The purpose of the project was to analyze the operational experience of nuclear units within the United States during the calendar years 1985 through 1986 using the Operating Plant Evaluation Code (OPEC-2) System and other available sources of operational data. The report updates and supplements previous EPRI reports NP-1191, NP-2092, NP-3480, and NP-4368. The overall performances of US nuclear units and the availability and capacity factor losses for the constituent systems and components are presented. The problem areas which have impacted most significantly on nuclear unit performance during 1985 to 1986 are discussed in detail. Forced outage rates and scram rates are also investigated. The 92 domestic nuclear units which were considered in this report inlcude all units which are rated 400 MW(e) or greater. Three Mile Island 2 was excluded from all analyses of this report. The performances of BWRs and PWRs in the United States during 1985 through 1986 were compared with similar units operating in foreign countries.

  13. Operational experience with the ATLAS Pixel Detector at the LHC

    NASA Astrophysics Data System (ADS)

    Lapoire, C.; Atlas Collaboration

    2013-01-01

    The ATLAS Pixel Detector is the innermost detector of the ATLAS experiment at the Large Hadron Collider at CERN, providing high-resolution measurements of charged particle tracks in the high radiation environment close to the collision region. This capability is vital for the identification and measurement of proper decay times of long-lived particles such as B-hadrons, and thus vital for the ATLAS physics program. The detector provides hermetic coverage with three cylindrical layers and three layers of forward and backward pixel detectors. It consists of approximately 80 million pixels that are individually read out via chips bump-bonded to 1744 n-in-n silicon substrates. In this paper, results from the successful operation of the Pixel Detector at the LHC will be presented, including monitoring, calibration procedures and detector performance. The detector performance is excellent: 96.2% of the pixels are operational, noise occupancy is sufficiently low and hit efficiency exceed the design specification.

  14. Superconducting radio-frequency modules test faciilty operating experience

    SciTech Connect

    Soyars, W.; Bossert, R.; Darve, C.; Degraff, B.; Klebaner, A.; Martinez, A.; Pei, L.; Theilacker, J.; /Fermilab

    2007-07-01

    Fermilab is heavily engaged and making strong technical contributions to the superconducting radio-frequency research and development program (SRF R&D). Four major SRF test areas are being constructed to enable vertical and horizontal cavity testing, as well as cryomodule testing. The existing Fermilab cryogenic infrastructure has been modified to service Fermilab SRF R&D needs. The first stage of the project has been successfully completed, which allows for distribution of cryogens for a single cavity cryomodule using the existing Cryogenic Test Facility (CTF) that houses three Tevatron satellite refrigerators. The cooling capacity available for cryomodule testing at MDB results from the liquefaction capacity of the CTF cryogenic system. The cryogenic system for a single 9-cell cryomodule is currently operational. The paper describes the status, challenges and operational experience of the initial phase of the project.

  15. Quantum Chemical Calculations Using Accelerators: Migrating Matrix Operations to the NVIDIA Kepler GPU and the Intel Xeon Phi.

    PubMed

    Leang, Sarom S; Rendell, Alistair P; Gordon, Mark S

    2014-03-11

    Increasingly, modern computer systems comprise a multicore general-purpose processor augmented with a number of special purpose devices or accelerators connected via an external interface such as a PCI bus. The NVIDIA Kepler Graphical Processing Unit (GPU) and the Intel Phi are two examples of such accelerators. Accelerators offer peak performances that can be well above those of the host processor. How to exploit this heterogeneous environment for legacy application codes is not, however, straightforward. This paper considers how matrix operations in typical quantum chemical calculations can be migrated to the GPU and Phi systems. Double precision general matrix multiply operations are endemic in electronic structure calculations, especially methods that include electron correlation, such as density functional theory, second order perturbation theory, and coupled cluster theory. The use of approaches that automatically determine whether to use the host or an accelerator, based on problem size, is explored, with computations that are occurring on the accelerator and/or the host. For data-transfers over PCI-e, the GPU provides the best overall performance for data sizes up to 4096 MB with consistent upload and download rates between 5-5.6 GB/s and 5.4-6.3 GB/s, respectively. The GPU outperforms the Phi for both square and nonsquare matrix multiplications. PMID:26580169

  16. Apollo experience report: Communications used during recovery operations

    NASA Technical Reports Server (NTRS)

    Hoover, J. E.

    1974-01-01

    Apollo program experience in recovery-support communications is reviewed, and the working relationships among NASA, the Department of Defense, and commercial communications facilities are discussed. The organization, facilities, philosophy, and funding of recovery-support communications are described. The relocation of two recovery control centers is discussed, as are the functions of primary and secondary recovery ships, aircraft, and relay satellities. The possibility of using ships of opportunity for recovery operations is considered. Finally, the means by which money, manpower, and resources have been saved and longlines leased are delineated.

  17. Autonomous Sciencecraft Experiment (ASE) Operations on EO-1 in 2004

    NASA Technical Reports Server (NTRS)

    Davies, A. G.; Baker, V.; Castano, R.; Chien, S.; Cichy, B.; Doggett, T.; Dohm, J. M.; Greeley, R.; Lee, R.; Sherwood, R.

    2004-01-01

    The Autonomous Sciencecraft Experiment (ASE) has been selected for flight demonstration by NASAs New Millennium Program (NMP) as part of the Space Technology 6 (ST6) mission. NASA has identified the development of an autonomously operating spacecraft as a necessity for an expanded program of missions exploring the Solar System. The versatile ASE spacecraft command and control software, image formation software, and science processing software will be uploaded to the Earth Observer 1 (EO-1) spacecraft in early 2004 to detect surface modification related to volcanism, ice formation and retreat, and flooding.

  18. Nevada Experiments and Operations Program (N Program) Management Plan

    SciTech Connect

    Nattrass, L.; Anastasio, M.R.

    2000-02-01

    This plan briefly describes the Lawrence Livermore National Laboratory (LLNL) institutional structure and how Nevada Experiments and Operations Program (N Program's) organization fits within this structure, roles and responsibilities, and management processes that govern N Program activities. This plan also serves as the Integrated Safety Management (ISM) Implementation Plan for N Program work. This plan applies to all work performed by and for LLNL that falls under the oversight of DOE/NV except LLNL activities in support of the Yucca Mountain Project Office (YMPO).

  19. Skylab Medical Experiments Altitude Test /SMEAT/ facility design and operation.

    NASA Technical Reports Server (NTRS)

    Hinners, A. H., Jr.; Correale, J. V.

    1973-01-01

    This paper presents the design approaches and test facility operation methods used to successfully accomplish a 56-day test for Skylab to permit evaluation of selected Skylab medical experiments in a ground test simulation of the Skylab environment with an astronaut crew. The systems designed for this test include the two-gas environmental control system, the fire suppression and detection system, equipment transfer lock, ground support equipment, safety systems, potable water system, waste management system, lighting and power system, television monitoring, communications and recreation systems, and food freezer.

  20. Experiments in hand-operated, hypersonic shock tunnel facility

    NASA Astrophysics Data System (ADS)

    Sudhiesh Kumar, Chintoo; Reddy, K. P. J.

    2015-12-01

    Experiments were conducted using the newly developed table-top, hand-operated hypersonic shock tunnel, otherwise known as the Reddy hypersonic shock tunnel. This novel instrument uses only manual force to generate the shock wave in the shock tube, and is designed to generate a freestream flow of Mach 6.5 in the test section. The flow was characterized using stagnation point pressure measurements made using fast-acting piezoelectric transducers. Schlieren visualization was also carried out to capture the bow shock in front of a hemispherical body placed in the flow. Freestream Mach numbers estimated at various points in the test section showed that for a minimum diameter of 46 mm within the test section, the value did not vary by more than 3 % along any cross-sectional plane. The results of the experiments presented here indicate that the device may be successfully employed for basic hypersonic research activities at the university level.

  1. Test particle acceleration in a numerical MHD experiment of an anemone jet

    NASA Astrophysics Data System (ADS)

    Rosdahl, K. J.; Galsgaard, K.

    2010-02-01

    Aims: To use a 3D numerical MHD experiment representing magnetic flux emerging into an open field region as a background field for tracing charged particles. The interaction between the two flux systems generates a localised current sheet where MHD reconnection takes place. We investigate how efficiently the reconnection region accelerates charged particles and what kind of energy distribution they acquire. Methods: The particle tracing is done numerically using the Guiding Center Approximation on individual data sets from the numerical MHD experiment. Results: We derive particle and implied photon distribution functions having power law forms, and look at the impact patterns of particles hitting the photosphere. We find that particles reach energies far in excess of those seen in observations of solar flares. However the structure of the impact region in the photosphere gives a good representation of the topological structure of the magnetic field. Three movies are only available in electronic form at http://www.aanda.org

  2. Recent accelerator experiments updates in Shielding INtegral Benchmark Archive Database (SINBAD)

    NASA Astrophysics Data System (ADS)

    Kodeli, I.; Sartori, E.; Kirk, B.

    2006-06-01

    SINBAD is an internationally established set of radiation shielding and dosimetry data relative to experiments relevant in reactor shielding, fusion blanket neutronics and accelerator shielding. In addition to the characterization of the radiation source, it describes shielding materials and instrumentation and the relevant detectors. The experimental results, be it dose, reaction rates or unfolded spectra are presented in tabular ASCII form that can easily be exported to different computer environments for further use. Most sets in SINBAD also contain the computer model used for the interpretation of the experiment and, where available, results from uncertainty analysis. The set of primary documents used for the benchmark compilation and evaluation are provided in computer readable form. SINBAD is available free of charge from RSICC and from the NEA Data Bank.

  3. Fusion-neutron measurements for magnetized liner inertial fusion experiments on the Z accelerator

    NASA Astrophysics Data System (ADS)

    Hahn, K. D.; Chandler, G. A.; Ruiz, C. L.; Cooper, G. W.; Gomez, M. R.; Slutz, S.; Sefkow, A. B.; Sinars, D. B.; Hansen, S. B.; Knapp, P. F.; Schmit, P. F.; Harding, E.; Jennings, C. A.; Awe, T. J.; Geissel, M.; Rovang, D. C.; Torres, J. A.; Bur, J. A.; Cuneo, M. E.; Glebov, V. Yu; Harvey-Thompson, A. J.; Herrman, M. C.; Hess, M. H.; Johns, O.; Jones, B.; Lamppa, D. C.; Lash, J. S.; Martin, M. R.; McBride, R. D.; Peterson, K. J.; Porter, J. L.; Reneker, J.; Robertson, G. K.; Rochau, G. A.; Savage, M. E.; Smith, I. C.; Styron, J. D.; Vesey, R. A.

    2016-05-01

    Several magnetized liner inertial fusion (MagLIF) experiments have been conducted on the Z accelerator at Sandia National Laboratories since late 2013. Measurements of the primary DD (2.45 MeV) neutrons for these experiments suggest that the neutron production is thermonuclear. Primary DD yields up to 3e12 with ion temperatures ∼2-3 keV have been achieved. Measurements of the secondary DT (14 MeV) neutrons indicate that the fuel is significantly magnetized. Measurements of down-scattered neutrons from the beryllium liner suggest ρRliner∼1g/cm2. Neutron bang times, estimated from neutron time-of-flight (nTOF) measurements, coincide with peak x-ray production. Plans to improve and expand the Z neutron diagnostic suite include neutron burn-history diagnostics, increased sensitivity and higher precision nTOF detectors, and neutron recoil-based yield and spectral measurements.

  4. Application of an electromagnetic accelerator to ultra-high-speed plastic deformation experiments

    NASA Astrophysics Data System (ADS)

    Okada, A.; Kiritani, M.

    2002-01-01

    An electromagnetic accelerator (railgun) is briefly introduced, and several examples of experimental results obtained from test runs of this facility are shown and merits of the application of the railgun to high-speed deformation experiments are emphasized. On applying this facility to high-speed deformation experiments, several specific adapters should be designed, such as a jig for applying a designed amount of deformation to a specimen, A specimen cooling system is also important, as a measure against severe temperature rise occurring during extraordinarily rapid deformation. Although application of the railgun involves many difficulties, the railgun is expected to be a very attractive tool for ultra-high-speed deformation research. The railgun can realize the ultra-high-speed deformation via the collision of a projectile and a target material at a speed comparable to the sonic wave velocity Such high speeds cannot be obtainable by other methods.

  5. Experience of Pseudospark Switch Operation in Pulse Power Applications

    NASA Astrophysics Data System (ADS)

    Voitenko, N. V.; Yudin, A. S.; Kuznetsova, N. S.; Bochkov, V. D.

    2015-11-01

    The paper demonstrates the results of TDIl-200k/25SN-P pseudospark switch (PSS) developed by Russian company "Pulsed Technologies Ltd" application. PSS was used in pulsed power unit intended for electric-discharge fracture of rocks and concrete blocks and splitting off from monolith. The pulsed power unit has a pulse current generator with the capacity of 560 μF, stored energy of up to 63 kJ, operating voltage of up to15 kV, current pulse amplitude of up to 200 kA and pulse duration more than 200 μsec. The study also shows the current waveforms determined in the short-circuit experiment of the pulse current generator and in the experiments of the electric-discharge fragmentation of concrete at the charging voltage of 13 kV. PSS was operated in ringing single-pulse mode with the exceedance of more than two maximum permissible parameters: current pulse amplitude, current pulse duration and maximum pulse energy. Internal electrode erosion of PSS is shown and possible reasons of asymmetric current feed are discussed.

  6. Theory of factors limiting high gradient operation of warm accelerating structures

    SciTech Connect

    Nusinovich, Gregory S.

    2014-07-22

    This report consists of two parts. In the first part we describe a study of the heating of microprotrusions on surfaces of accelerating structures. This ;process is believed to lead to breakdown in these structures. Our study revealed that for current accelerator parameters melting should not occur due to space charge limitations of the current emitted by a protrusion. The second part describes a novel concept to develop THz range sources based on harmonic cyclotron masers for driving future colliders. This work was stimulated by a recent request of SLAC to develop high power, high-efficiency sources of sub-THz radiation for future high-gradient accelerators.

  7. Operational Experience with Autonomous Star Trackers on ESA Interplanetary Spacecraft

    NASA Technical Reports Server (NTRS)

    Lauer, Mathias; Jauregui, Libe; Kielbassa, Sabine

    2007-01-01

    Mars Express (MEX), Rosetta and Venus Express (VEX) are ESA interplanetary spacecrafts (S/C) launched in June 2003, March 2004 and November 2005, respectively. Mars Express was injected into Mars orbit end of 2003 with routine operations starting in spring 2004. Rosetta is since launch on its way to rendezvous comet Churyumov-Gerasimenko in 2014. It has completed several test and commissioning activities and is performing several planetary swingbys (Earth in spring 2005, Mars in spring 2007, Earth in autumn 2007 and again two years later). Venus Express has also started routine operations since the completion of the Venus orbit insertion maneuver sequence beginning of May 2006. All three S/C are three axes stabilized with a similar attitude and orbit control system (AOCS). The attitude is estimated on board using star and rate sensors and controlled using four reaction wheels. A bipropellant reaction control system with 10N thrusters serves for wheel off loadings and attitude control in safe mode. Mars Express and Venus Express have an additional 400N engine for the planetary orbit insertion. Nominal Earth communication is accomplished through a high gain antenna. All three S/C are equipped with a redundant set of autonomous star trackers (STR) which are based on almost the same hardware. The STR software is especially adapted for the respective mission. This paper addresses several topics related to the experience gained with the STR operations on board the three S/C so far.

  8. Geostationary Operational Environmental Satellite (GOES)-8 mission flight experience

    NASA Technical Reports Server (NTRS)

    Noonan, C. H.; Mcintosh, R. J.; Rowe, J. N.; Defazio, R. L.; Galal, K. F.

    1995-01-01

    The Geostationary Operational Environmental Satellite (GOES)-8 spacecraft was launched on April 13, 1994, at 06:04:02 coordinated universal time (UTC), with separation from the Atlas-Centaur launch vehicle occurring at 06:33:05 UTC. The launch was followed by a series of complex, intense operations to maneuver the spacecraft into its geosynchronous mission orbit. The Flight Dynamics Facility (FDF) of the Goddard Space Flight Center (GSFC) Flight Dynamics Division (FDD) was responsible for GOES-8 attitude, orbit maneuver, orbit determination, and station acquisition support during the ascent phase. This paper summarizes the efforts of the FDF support teams and highlights some of the unique challenges the launch team faced during critical GOES-8 mission support. FDF operations experience discussed includes: (1) The abort of apogee maneuver firing-1 (AMF-1), cancellation of AMF-3, and the subsequent replans of the maneuver profile; (2) The unexpectedly large temperature dependence of the digital integrating rate assembly (DIRA) and its effect on GOES-8 attitude targeting in support of perigee raising maneuvers; (3) The significant effect of attitude control thrusting on GOES-8 orbit determination solutions; (4) Adjustment of the trim tab to minimize torque due to solar radiation pressure; and (5) Postlaunch analysis performed to estimate the GOES-8 separation attitude. The paper also discusses some key FDF GOES-8 lessons learned to be considered for the GOES-J launch which is currently scheduled for May 19, 1995.

  9. Dynamics of plasma flow formation in a pulsed accelerator operating at a constant pressure

    NASA Astrophysics Data System (ADS)

    Baimbetov, F. B.; Zhukeshov, A. M.; Amrenova, A. U.

    2007-01-01

    Features in the dynamics of plasma flow formation at a constant pressure in a pulsed coaxial accelerator have been studied. The temperature and density of electrons in a plasma bunch have been determined using a probe technique.

  10. PROPOSAL FOR A PRE-BUNCHED LASER WAKEFIELD ACCELERATION EXPERIMENT AT THE BNL DUV FEL FACILITY.

    SciTech Connect

    WANG,X.J.SHEEHY,B.WU,Z.GAI,W.TING,A.

    2003-05-12

    We propose a pre-bunched Laser Wakefield Acceleration (LWFA) experiment in a plasma channel at the BNL DUV-FEL Facility. BNL DUV-FEL facility is uniquely qualified to carry out the proposed experiment because of the high-brightness' electron beam and RF synchronized TW Ti:Sapphire laser system. The DUV-FEL is a 200 MeV linac facility equipped with a photocathode RF gun injector, a 100 fs Ti:Sapphire laser system and a magnetic bunch compressor. The proposed LWFA will inject a 150 MeV, 10 fs electron bunch into a centimeters long plasma channel. Simulation and preliminary experiment showed that, high-brightness 10 fs electron bunch with 20 pC charge could be produced using the technique of longitudinal emittance compensation. The initial experiment will be performed using the existing Ti:Sapphire laser system (50mJ, 100 fs) with 30 {micro}m spot and 4 cm channel, the maximum energy gain will be about 15 MeV. We propose to upgrade the existing SDL laser output to 500 mJ with a shorter pulse length (50 fs). For an electron beam spot size of 20 um, the expected energy gain is about 100 MeV for a 5 TW, 50 fs laser pulse.

  11. Statistical comparison between experiments and numerical simulations of shock-accelerated gas cylinders

    SciTech Connect

    Rider, William; Kamm, J. R.; Zoldi, C. A.; Tomkins, C. D.

    2002-01-01

    We present detailed spatial analysis comparing experimental data and numerical simulation results for Richtmyer-Meshkov instability experiments of Prestridge et al. and Tomkins et al. These experiments consist, respectively, of one and two diffuse cylinders of sulphur hexafluoride (SF{sub 6}) impulsively accelerated by a Mach 1.2 shockwave in air. The subsequent fluid evolution and mixing is driven by the deposition of baroclinic vorticity at the interface between the two fluids. Numerical simulations of these experiments are performed with three different versions of high resolution finite volume Godunov methods, including a new weighted adaptive Runge-Kutta (WARK) scheme. We quantify the nature of the mixing using using integral measures as well as fractal analysis and continuous wavelet transforms. Our investigation of the gas cylinder configurations follows the path of our earlier studies of the geometrically and dynamically more complex gas 'curtain' experiment. In those studies, we found significant discrepancies in the details of the experimentally measured mixing and the details of the numerical simulations. Here we evaluate the effects of these hydrodynamic integration techniques on the diffuse gas cylinder simulations, which we quantitatively compare with experimental data.

  12. The conversion of CESR to operate as the Test Accelerator, CesrTA. Part 1: overview

    NASA Astrophysics Data System (ADS)

    Billing, M. G.

    2015-07-01

    Cornell's electron/positron storage ring (CESR) was modified over a series of accelerator shutdowns beginning in May 2008, which substantially improves its capability for research and development for particle accelerators. CESR's energy span from 1.8 to 5.6 GeV with both electrons and positrons makes it ideal for the study of a wide spectrum of accelerator physics issues and instrumentation related to present light sources and future lepton damping rings. Additionally a number of these are also relevant for the beam physics of proton accelerators. This paper outlines the motivation, design and conversion of CESR to a test accelerator, CESRTA, enhanced to study such subjects as low emittance tuning methods, electron cloud (EC) effects, intra-beam scattering, fast ion instabilities as well as general improvements to beam instrumentation. While the initial studies of CESRTA focussed on questions related to the International Linear Collider (ILC) damping ring design, CESRTA is a very flexible storage ring, capable of studying a wide range of accelerator physics and instrumentation questions. This paper contains the outline and the basis for a set of papers documenting the reconfiguration of the storage ring and the associated instrumentation required for the studies described above. Further details may be found in these papers.

  13. LANL OPERATING EXPERIENCE WITH THE WAND AND HERCULES PROTOTYPE SYSTEMS

    SciTech Connect

    K. M. GRUETZMACHER; C. L. FOXX; S. C. MYERS

    2000-09-01

    The Waste Assay for Nonradioactive Disposal (WAND) and the High Efficiency Radiation Counters for Ultimate Low Emission Sensitivity (HERCULES) prototype systems have been operating at Los Alamos National Laboratory's (LANL's) Solid Waste Operation's (SWO'S) non-destructive assay (NDA) building since 1997 and 1998, respectively. These systems are the cornerstone of the verification program for low-density Green is Clean (GIC) waste at the Laboratory. GIC waste includes all non-regulated waste generated in radiological controlled areas (RCAS) that has been actively segregated as clean (i.e., nonradioactive) through the use of waste generator acceptable knowledge (AK). The use of this methodology alters LANL's past practice of disposing of all room trash generated in nuclear facilities in radioactive waste landfills. Waste that is verified clean can be disposed of at the Los Alamos County Landfill. It is estimated that 50-90% of the low-density room trash from radioactive material handling areas at Los Alamos might be free of contamination. This approach avoids the high cost of disposal of clean waste at a radioactive waste landfill. It also reduces consumption of precious space in the radioactive waste landfill where disposal of this waste provides no benefit to the public or the environment. Preserving low level waste (LLW) disposal capacity for truly radioactive waste is critical in this era when expanding existing radioactive waste landfills or permitting new ones is resisted by regulators and stakeholders. This paper describes the operating experience with the WAND and HERCULES since they began operation at SWO. Waste for verification by the WAND system has been limited so far to waste from the Plutonium Facility and the Solid Waste Operations Facility. A total of461 ft3 (13.1 m3) of low-density shredded waste and paper have been verified clean by the WAND system. The HERCULES system has been used to verify waste from four Laboratory facilities. These are the

  14. Experience in using workstations as hosts in an accelerator control environment

    SciTech Connect

    Abola, A.; Casella, R.; Clifford, T.; Hoff, L.; Katz, R.; Kennell, S.; Mandell, S.; McBreen, E.; Weygand, D.P.

    1987-03-01

    A new control system has been used for light ion acceleration at the Alternating Gradient Synchrotron (AGS). The control system uses Apollo workstations in the dual role of console hardware computer and controls system host. It has been found that having a powerful dedicated CPU with a demand paging virtual memory OS featuring strong interprocess communication, mapped memory shared files, shared code, and multi-window capabilities, allows us to provide an efficient operation environment in which users may view and manage several control processes simultaneously. The same features which make workstations good console computers also provide an outstanding platform for code development. The software for the system, consisting of about 30K lines of ''C'' code, was developed on schedule, ready for light ion commissioning. System development is continuing with work being done on applications programs.

  15. Experiments on 1,000 km/s flyer acceleration and collisions

    NASA Astrophysics Data System (ADS)

    Karasik, Max; Weaver, J. L.; Aglitskiy, Y.; Kehne, D. M.; Zalesak, S. T.; Velikovich, A. L.; Oh, J.; Serlin, V.; Obenschain, S. P.

    2012-10-01

    We will present results from follow-on experiments to the record-high velocities achieved using the ultra-uniform deep-uv drive of the Nike KrF laser [Karasik et al, Phys. Plasmas 17, 056317 (2010)], in which highly accelerated planar foils of deuterated polystyrene were made to collide with a witness foil to produce ˜1 Gbar shock pressures and result in heating of matter to thermonuclear temperatures. Such velocities may indicate a path to lower minimum energy required for central ignition. Still higher velocities and higher target densities are required for impact fast ignition. New results give velocity of >1,100 km/s achieved through improvements in pulseshaping. Variation of second foil parameters results in significant change in fusion neutron production on impact. In-flight target density is inferred from target heating upon collision via DD neutron time-of-flight ion temperature measurement. Availability of pressures generated by collisions of such highly accelerated flyers may provide an experimental platform for study of matter at extreme conditions. Work is supported by US DOE (NNSA).

  16. Laboratory Experiments with the Concordia College High-Speed Dust Particle Accelerator

    NASA Astrophysics Data System (ADS)

    Manning, H. L.

    2011-12-01

    During the Apollo Era, NASA's Goddard Space Flight Center built a 2MeV high-speed, dust particle accelerator. This facility was used to test and calibrate the LEAM instrument which was flown to the lunar surface by Apollo 17. As the Apollo project wound down, NASA no longer had need of the dust particle accelerator, and in 1975, it was move to Concordia College in Moorhead, MN. Through the years, it has been maintained and some modifications and improvements have been made to it. In the past decade, the facility has been revived and used by several collaborating institutions to study dust detector instrumentation as well as the effects of dust impacts on various materials. We have tested a prototype, space-flight dust particle detector. Also, piezoelectric pins which can be used as dust detectors were studied to learn the pin's response to single particle impacts of different energies and momenta, and then those measured responses were compared with theoretical models. The effects of high speed impacts on ultra-high temperature ceramics, aerogel, and several different thin films have also been studied at our facility. The results of these experiments will be presented.

  17. Electron Acceleration and Ionization Production in High-Power Heating Experiments at HAARP

    NASA Astrophysics Data System (ADS)

    Mishin, E. V.; Pedersen, T.

    2012-12-01

    Recent ionospheric modification experiments with the 3.6 MW transmitter at the High Frequency Active Auroral Research Program (HAARP) facility in Alaska led to discovery of artificial ionization descending from the nominal interaction altitude in the background F-region ionosphere by ~60-80 km. Artificial ionization production is indicated by significant 427.8 nm emissions from the 1st negative band of N2+ and the appearance of transmitter-induced bottomside traces in ionosonde data during the periods of most intense optical emissions. However, the exact mechanisms producing the artificial plasmas remain to be determined. Yet the only existing theoretical models explain the development of artificial plasma as an ionizing wavefront moving downward due to ionization by electrons accelerated by HF-excited strong Langmuir turbulence (SLT) generated near the plasma resonance, where the pump frequency matches the plasma frequency. However, the observations suggest also the significance of interactions with upper hybrid and electron Bernstein waves near multiples of the electron gyrofrequency. We describe recent observations and discuss suitable acceleration mechanisms.

  18. APS storage ring commissioning and early operational experience

    SciTech Connect

    Decker, G.

    1995-07-01

    The Advanced Photon Source (APS) at Argonne National Laboratory (ANL) uses a 100-mA, 7-GeV positron storage ring to produce high brilliance bending magnet and insertion device x-rays for up to 70 x-ray beamlines. It is 1104 meters in circumference and has a beam liftime designed to exceed 10 hours with 1 nTorr average ring vacuum at 100 mA. The high brilliance required by the synchrotron light users results from the storage ring`s natural emittance of 8.2 nm-rad, together with the requirement that the beam be stable to a level which is less than 5% of its rms size. Real-time closed orbit feedback is employed to achieve the required stability and is discussed elsewhere in these proceedings. Installation of storage ring components was completed early this year, and we report here on the first experiences of commissioning and operation with beam.

  19. Using Information from Operating Experience to Inform Human Reliability Analysis

    SciTech Connect

    Bruce P. Hallbert; David I. Gertman; Julie Marble; Erasmia Lois; Nathan Siu

    2004-06-01

    This paper reports on efforts being sponsored by the U.S. NRC and performed by INEEL to develop a technical basis and perform work to extract information from sources for use in HRA. The objectives of this work are to: 1) develop a method for conducting risk-informed event analysis of human performance information that stems from operating experience at nuclear power plants and for compiling and documenting the results in a structured manner; 2) provide information from these analyses for use in risk-informed and performance-based regulatory activities; 3) create methods for information extraction and a repository for this information that, likewise, support HRA methods and their applications.

  20. Experiment of a centrifugal pump during changing speed operation

    NASA Astrophysics Data System (ADS)

    Yuan, H. J.; Shao, J.; Wu, Y. L.; Liu, S. H.

    2012-11-01

    In this paper, a method of changing rotational speed of impeller periodically as the pulsatile working condition is developed to realize pulse outputs both of flow discharge and of head for a centrifugal pump through experiment. The performance of the centrifugal pump under pulsatile working operation condition is measured which indicates this model pump could produce desired pulse flow under such condition. Flow patterns at four testing points under pulsatile conditions are obtained by means of the particle image velocimetry (PIV) technology both with laser induced fluorescence (LIF) particles and refractive index matched (RIM) fluid. Results of PIV measurement show the distributions of velocity, streamlines, and the principal Reynolds normal stress (PRNS). Under the design flow rate condition, the relative velocity in the blade channel distributes smoothly and decreases from inlet to exit. And at the impeller exit, the relative velocity is lower close to suction side than that near pressure side of blade in most of blade channels.

  1. Operational experience running Hadoop XRootD Fallback

    NASA Astrophysics Data System (ADS)

    Dost, J. M.; Tadel, A.; Tadel, M.; Würthwein, F.

    2015-12-01

    In April of 2014, the UCSD T2 Center deployed hdfs-xrootd-fallback, a UCSD- developed software system that interfaces Hadoop with XRootD to increase reliability of the Hadoop file system. The hdfs-xrootd-fallback system allows a site to depend less on local file replication and more on global replication provided by the XRootD federation to ensure data redundancy. Deploying the software has allowed us to reduce Hadoop replication on a significant subset of files in our cluster, freeing hundreds of terabytes in our local storage, and to recover HDFS blocks lost due to storage degradation. An overview of the architecture of the hdfs-xrootd-fallback system will be presented, as well as details of our experience operating the service over the past year.

  2. Initial Operation of the Maryland Coaxial Gyroklystron Experiment

    NASA Astrophysics Data System (ADS)

    Lawson, W.; Castle, M.; Cheng, J.; Hogan, B.; Saraph, G. P.; Granatstein, V. L.; Reiser, M.

    1997-05-01

    We describe results from the initial operation of our coaxial gyroklystron experiment, which is being evaluated as a potential driver for future linear colliders. The interaction is designed to occur between a 500 kV, 500-700 A beam and a series of coaxial TE_0n1 microwave cavities. Output powers in excess of 100 MW at 8.568 GHz are expected with an efficiency of about 40%. We detail performance of our single anode magnetron injection gun in addition to the stability and amplification properties of our preliminary microwave circuit. We also discuss our designs of near-term future tubes which are expected to have comparable performance at 17.136 GHz. ^* G.P. Saraph, W. Lawson, M. Castle, J. Cheng, J.P. Calame, and G.S. Nusinovich, IEEE Trans. Plasma Sci. 24 (1996) \\underline671.

  3. Operational experience feedback in the World Association of Nuclear Operators (WANO).

    PubMed

    Revuelta, Ramon

    2004-07-26

    Operators in high-risk industries need to be learning organisations, learning from themselves and from the others. This presentation will describe how the nuclear industry is dealing in an integrated manner with the feedback of operating experience (OE), both internal and external, to increase the safety and reliability of power plants; it will describe how it; investigates events, reports events and analyses trends, shares information to prevent recurrence, performs corrective action and training, performs assessments to verify effectiveness. The plants have achieved great improvements in performance overall, and to improve further, the industry is evolving. Instead of just learning from past events (reactive) it is now focusing on lower level indications of problems (precursors) through low level events reporting, trending and analysis. A hallmark of the industry is its desire to be self-critical. Emphasis is placed on improving the bottom quartile performing plants. PMID:15231349

  4. The LHCb Online Framework for Experiment Protection, and Global Operational Control and Monitoring

    NASA Astrophysics Data System (ADS)

    Alessio, F.; Jacobsson, R.; Schleich, S.

    2011-12-01

    The complexity and extreme parameters of the LHC, such as the stored energy, the collision frequency, the high risk of adverse background conditions and potentially damaging beam losses have demanded an unprecedented connectivity between the operation of the accelerator and the experiments at both hardware and software level. LHCb has been at the forefront of developing a software framework and hardware which connects to all of the LHC communication interfaces for timing, control and monitoring of the machine and beam parameters, in addition to its own local systems for beam and background monitoring. The framework also includes failsafe connectivity with the beam interlock system. The framework drives the global operation of the detector and is integrated into the readout control. It provides the shifters with the tools needed to take fast and well-guided decisions to run the LHCb experiment safely and efficiently. In particular, it has allowed the detector to be operated with only two shifters already at the LHC pilot run. The requirements include reliability and clarity for the shifters, and the possibility to retrieve the past conditions for offline analysis. All essential parameters are archived and an interactive analysis tool has been developed which provides overviews of the experimental performance and which allows post-analysis of any anomaly in the operation. This paper describes the architecture and the many functions, including the basis of the automation of the LHCb operational procedure and detector controls, and the information exchange between LHCb and the LHC, and finally the shifter and expert tools for monitoring the experimental conditions.

  5. Colliding pulse injection experiments in non-collinear geometryfor controlled laser plasma wakefield acceleration of electrons

    SciTech Connect

    Toth, Carl B.; Esarey, Eric H.; Geddes, Cameron G.R.; Leemans,Wim P.; Nakamura, Kei; Panasenko, Dmitriy; Schroeder, Carl B.; Bruhwiler,D.; Cary, J.R.

    2007-06-25

    An optical injection scheme for a laser-plasma basedaccelerator which employs a non-collinear counter-propagating laser beamto push background electrons in the focusing and acceleration phase viaponderomotive beat with the trailing part of the wakefield driver pulseis discussed. Preliminary experiments were performed using a drive beamof a_0 = 2.6 and colliding beam of a_1 = 0.8 both focused on the middleof a 200 mu m slit jet backed with 20 bar, which provided ~; 260 mu mlong gas plume. The enhancement in the total charge by the collidingpulse was observed with sharp dependence on the delay time of thecolliding beam. Enhancement of the neutron yield was also measured, whichsuggests a generation of electrons above 10 MeV.

  6. Do US Black Women Experience Stress-Related Accelerated Biological Aging?

    PubMed Central

    Hicken, Margaret T.; Pearson, Jay A.; Seashols, Sarah J.; Brown, Kelly L.; Cruz, Tracey Dawson

    2010-01-01

    We hypothesize that black women experience accelerated biological aging in response to repeated or prolonged adaptation to subjective and objective stressors. Drawing on stress physiology and ethnographic, social science, and public health literature, we lay out the rationale for this hypothesis. We also perform a first population-based test of its plausibility, focusing on telomere length, a biomeasure of aging that may be shortened by stressors. Analyzing data from the Study of Women's Health Across the Nation (SWAN), we estimate that at ages 49–55, black women are 7.5 years biologically “older” than white women. Indicators of perceived stress and poverty account for 27% of this difference. Data limitations preclude assessing objective stressors and also result in imprecise estimates, limiting our ability to draw firm inferences. Further investigation of black-white differences in telomere length using large-population-based samples of broad age range and with detailed measures of environmental stressors is merited. PMID:20436780

  7. Startup Studies and Initial Operations of the PEGASUS Toroidal Experiment*

    NASA Astrophysics Data System (ADS)

    Thorson, T.; Dannhausen, D.; Fonck, R.; Intrator, T.; Lewicki, B.; Sontag, A.; Tritz, K.; Wilson, C.

    1998-11-01

    Optimization of ohmic flux consumption is an issue for present day spherical toroidal experiments (ST's) due to the relatively small amount of volt-seconds available for devices running at low aspect ratio (A). This is especially true for P EGASUS (A ~ 1.1), where presently up to 60 kW of electron cyclotron resonance (ECR) preionization (at 5.5 GHz) along with ohmic induction are used for plasma initiation. Available startup optimization techniques include varying the timing and strength of the inductive voltage, the fields from the internal coils for null formation, and the external vertical field during the plasma current ramp-up phase. Since impurity radiation can be a large power loss during startup, wall conditioning techniques, including He glow discharge cleaning and boronization, will also be used to improve startup efficiency and overall plasma performance. Initial operations of P EGASUS focus on exploring the Extremely Low Aspect Ratio Tokamak (ELART) regime of operation (A < 1.2) with low toroidal field (< 0.1 T on axis). * *Supported by U.S. DoE grant No. DE-FG02-96ER54375

  8. Avoiding Human Error in Mission Operations: Cassini Flight Experience

    NASA Technical Reports Server (NTRS)

    Burk, Thomas A.

    2012-01-01

    Operating spacecraft is a never-ending challenge and the risk of human error is ever- present. Many missions have been significantly affected by human error on the part of ground controllers. The Cassini mission at Saturn has not been immune to human error, but Cassini operations engineers use tools and follow processes that find and correct most human errors before they reach the spacecraft. What is needed are skilled engineers with good technical knowledge, good interpersonal communications, quality ground software, regular peer reviews, up-to-date procedures, as well as careful attention to detail and the discipline to test and verify all commands that will be sent to the spacecraft. Two areas of special concern are changes to flight software and response to in-flight anomalies. The Cassini team has a lot of practical experience in all these areas and they have found that well-trained engineers with good tools who follow clear procedures can catch most errors before they get into command sequences to be sent to the spacecraft. Finally, having a robust and fault-tolerant spacecraft that allows ground controllers excellent visibility of its condition is the most important way to ensure human error does not compromise the mission.

  9. Operational experience with the ATLAS Pixel detector at the LHC

    NASA Astrophysics Data System (ADS)

    Deluca, C.

    2011-12-01

    The ATLAS Pixel Detector is the innermost detector of the ATLAS experiment at the Large Hadron Collider at CERN, providing high-resolution measurements of charged particle tracks in the high radiation environment close to the collision region. This capability is vital for the identification and measurement of proper decay times of pico-seconds lifetime particles such as b-hadrons, and thus vital for the ATLAS physics program. The detector provides hermetic coverage with three cylindrical layers and three layers of forward and backward pixel detectors. It consists of approximately 80 million pixels that are individually read out via chips bump-bonded to 1744 n-in-n silicon substrates. In this paper, results from the successful operation of the Pixel Detector at the LHC will be presented, including monitoring, calibration procedures, timing optimization and detector performance. The detector performance is excellent: 97.5% of the pixels are operational, noise occupancy and hit efficiency exceed the design specification, and a good alignment allows high quality track resolution.

  10. Industrial operating experience of the GTE ceramic recuperator

    SciTech Connect

    Gonzalez, J.M.; Ferri, J.L. ); Rebello, W.J. )

    1990-06-01

    GTE Products Corporation, under a jointly funded program with the US Department of Energy (DOE), developed a compact ceramic high temperature recuperator that could recover heat from a relatively clean exhaust gases at temperatures up to of 2500{degree}F. The DOE program was very successful in that it allowed GTE to improve the technical and economic characteristics of the recuperator and stimulate industrial acceptance of the recuperator as an energy- saving technology. The success of the DOE Program was measured by the fact that from January 1981 to December 1984, 561 recuperators were installed by GTE on new or retrofitted furnaces. One objective of this contract was to conduct a telephone survey of the industrial plants that use the recuperator to determine their operating experience, present status, and common problems, and thus to complete the historical picture. Additionally, recuperators were returned to GTE after operating on industrial furnaces, and a post mortem'' analysis was undertaken with a goal of identifying the potential reason(s) for premature failure of the ceramic matrix. When contamination of the matrix was evident, historical data and spectrographic analysis were used to identify the type of contaminant, and its source. This effort has shown the type of degradation that occurs and has identified system design techniques that can be used to maximize the ceramic recuperator life cycle. 12 refs., 14 figs., 13 tabs.

  11. Imaging system QA of a medical accelerator, Novalis Tx, for IGRT per TG 142: our 1 year experience.

    PubMed

    Chang, Zheng; Bowsher, James; Cai, Jing; Yoo, Sua; Wang, Zhiheng; Adamson, Justus; Ren, Lei; Yin, Fang-Fang

    2012-01-01

    American Association of Physicists in Medicine (AAPM) task group (TG) 142 has recently published a report to update recommendations of the AAPM TG 40 report and add new recommendations concerning medical accelerators in the era of image-guided radiation therapy (IGRT). The recommendations of AAPM TG 142 on IGRT are timely. In our institute, we established a comprehensive imaging QA program on a medical accelerator based on AAPM TG 142 and implemented it successfully. In this paper, we share our one-year experience and performance evaluation of an OBI capable linear accelerator, Novalis Tx, per TG 142 guidelines. PMID:22766946

  12. Non-LTE radiative transfer with lambda-acceleration - Convergence properties using exact full and diagonal lambda-operators

    NASA Technical Reports Server (NTRS)

    Macfarlane, J. J.

    1992-01-01

    We investigate the convergence properties of Lambda-acceleration methods for non-LTE radiative transfer problems in planar and spherical geometry. Matrix elements of the 'exact' A-operator are used to accelerate convergence to a solution in which both the radiative transfer and atomic rate equations are simultaneously satisfied. Convergence properties of two-level and multilevel atomic systems are investigated for methods using: (1) the complete Lambda-operator, and (2) the diagonal of the Lambda-operator. We find that the convergence properties for the method utilizing the complete Lambda-operator are significantly better than those of the diagonal Lambda-operator method, often reducing the number of iterations needed for convergence by a factor of between two and seven. However, the overall computational time required for large scale calculations - that is, those with many atomic levels and spatial zones - is typically a factor of a few larger for the complete Lambda-operator method, suggesting that the approach should be best applied to problems in which convergence is especially difficult.

  13. Optimization of accelerator target and detector for portal imaging using Monte Carlo simulation and experiment

    NASA Astrophysics Data System (ADS)

    Flampouri, S.; Evans, P. M.; Verhaegen, F.; Nahum, A. E.; Spezi, E.; Partridge, M.

    2002-09-01

    Megavoltage portal images suffer from poor quality compared to those produced with kilovoltage x-rays. Several authors have shown that the image quality can be improved by modifying the linear accelerator to generate more low-energy photons. This work addresses the problem of using Monte Carlo simulation and experiment to optimize the beam and detector combination to maximize image quality for a given patient thickness. A simple model of the whole imaging chain was developed for investigation of the effect of the target parameters on the quality of the image. The optimum targets (6 mm thick aluminium and 1.6 mm copper) were installed in an Elekta SL25 accelerator. The first beam will be referred to as Al6 and the second as Cu1.6. A tissue-equivalent contrast phantom was imaged with the 6 MV standard photon beam and the experimental beams with standard radiotherapy and mammography film/screen systems. The arrangement with a thin Al target/mammography system improved the contrast from 1.4 cm bone in 5 cm water to 19% compared with 2% for the standard arrangement of a thick, high-Z target/radiotherapy verification system. The linac/phantom/detector system was simulated with the BEAM/EGS4 Monte Carlo code. Contrast calculated from the predicted images was in good agreement with the experiment (to within 2.5%). The use of MC techniques to predict images accurately, taking into account the whole imaging system, is a powerful new method for portal imaging system design optimization.

  14. Operational Experience with the Frontier System in CMS

    NASA Astrophysics Data System (ADS)

    Blumenfeld, Barry; Dykstra, Dave; Kreuzer, Peter; Du, Ran; Wang, Weizhen

    2012-12-01

    The Frontier framework is used in the CMS experiment at the LHC to deliver conditions data to processing clients worldwide, including calibration, alignment, and configuration information. Each central server at CERN, called a Frontier Launchpad, uses tomcat as a servlet container to establish the communication between clients and the central Oracle database. HTTP-proxy Squid servers, located close to clients, cache the responses to queries in order to provide high performance data access and to reduce the load on the central Oracle database. Each Frontier Launchpad also has its own reverse-proxy Squid for caching. The three central servers have been delivering about 5 million responses every day since the LHC startup, containing about 40 GB data in total, to more than one hundred Squid servers located worldwide, with an average response time on the order of 10 milliseconds. The Squid caches deployed worldwide process many more requests per day, over 700 million, and deliver over 40 TB of data. Several monitoring tools of the tomcat log files, the accesses of the Squids on the central Launchpad servers, and the availability of remote Squids have been developed to guarantee the performance of the service and make the system easily maintainable. Following a brief introduction of the Frontier framework, we describe the performance of this highly reliable and stable system, detail monitoring concerns and their deployment, and discuss the overall operational experience from the first two years of LHC data-taking.

  15. Systematic Study of Spin Effects at SPASCHARM Experiment at 70-GeV Accelerator in Protvino

    NASA Astrophysics Data System (ADS)

    Mochalov, V. V.; Abramov, V. V.; Bazhanov, N. A.; Borisov, N. S.; Derevschikov, A. A.; Evdokimova, A. S.; Meshchanin, A. P.; Minaev, N. G.; Morozov, D. A.; Nurushev, S. B.; Ryzhikov, S. V.; Semenov, P. A.; Ryazantsev, A. V.; Strikhanov, M. N.; Rykov, V. L.; Usov, Y. A.; Vasiliev, A. N.

    2016-02-01

    A new experiment SPASCHARM for systematic study of polarization phenomena in the inclusive and exclusive hadronic reactions in the energy range of IHEP accelerator U-70 (12-50GeV) is currently under development. The universal experimental setup will detect dozens of various resonances and stable particles produced in collisions of unpolarized beams with the polarized target, and at the next stage, using polarized proton and antiproton beams. At the beginning, the final states consisting of light quarks (u, d, s) will be reconstructed, and later on the charmonium states will be studied. Measurements are planned for a variety of beams: π±,K±,p, antiprotons. Hyperon polarization and spin density matrix elements of the vector mesons will be measured along with the single-spin asymmetry (SSA). The 2π-acceptance in azimuth, which is extremely useful for reduction of systematic errors in measurements of spin observables, will be implemented in the experiment. The solid angle acceptance of the setup, Δθ ≈ 250 mrad vertically and 350 mrad horizontally in the beam fragmentation region, covers a wide range of kinematic variables pT and xF. This provides the opportunity for separating dependences on these two variables which is usually not possible in the setups with a small solid angle acceptance. Unlike some previous polarization experiments, the SPASCHARM will be able to simultaneously accumulate and record data on the both, charged and neutral particle production.

  16. ATTO SECOND ELECTRON BEAMS GENERATION AND CHARACTERIZATION EXPERIMENT AT THE ACCELERATOR TEST FACILITY.

    SciTech Connect

    ZOLOTOREV, M.; ZHOLENTS, A.; WANG, X.J.; BABZIEN, M.; SKARITKA, J.; RAKOWSKY, G.; YAKIMENKO, V.

    2002-02-01

    We are proposing an Atto-second electron beam generation and diagnostics experiment at the Brookhaven Accelerator Test facility (ATF) using 1 {micro}m Inverse Free Electron Laser (IFEL). The proposed experiment will be carried out by an BNL/LBNL collaboration, and it will be installed at the ATF beam line II. The proposed experiment will employ a one-meter long undulator with 1.8 cm period (VISA undulator). The electron beam energy will be 63 MeV with emittance less than 2 mm-mrad and energy spread less than 0.05%. The ATF photocathode injector driving laser will be used for energy modulation by Inverse Free Electron Laser (IFEL). With 10 MW laser peak power, about 2% total energy modulation is expected. The energy modulated electron beam will be further bunched through either a drift space or a three magnet chicane into atto-second electron bunches. The attosecond electron beam bunches will be analyzed using the coherent transition radiation (CTR).

  17. Commissioning and early experience with a new-generation low-energy linear accelerator with advanced delivery and imaging functionalities

    PubMed Central

    2011-01-01

    Background A new-generation low-energy linear accelerator (UNIQUE) was introduced in the clinical arena during 2009 by Varian Medical Systems. The world's first UNIQUE was installed at Oncology Institute of Southern Switzerland and put into clinical operation in June 2010. The aim of the present contribution was to report experience about its commissioning and first year results from clinical operation. Methods Commissioning data, beam characteristics and the modeling into the treatment planning system were summarized. Imaging system of UNIQUE included a 2D-2D matching capability and tests were performed to identify system repositioning capability. Finally, since the system is capable of delivering volumetric modulated arc therapy with RapidArc, a summary of the tests performed for such modality to assess its performance in preclinical settings and during clinical usage was included. Results Isocenter virtual diameter was measured as less than 0.2 mm. Observed accuracy of isocenter determination and repositioning for 2D-2D matching procedures in image guidance was <1.2 mm. Concerning reproducibility and stability over a period of 1 year, deviations from reference were found <0.3 ± 0.2% for linac output, <0.1% for homogeneity, similarly to symmetry. Rotational accuracy of the entire gantry-portal imager system showed a maximum deviation from nominal 0.0 of <1.2 mm. Pre treatment quality assurance of RapidArc plans resulted with a Gamma Agreement Index (fraction of points passing the gamma criteria) of 97.0 ± 1.6% on the first 182 arcs verified. Conclusions The results of the commissioning tests and of the first period of clinical operation, resulted meeting specifications and having good margins respect to tolerances. UNIQUE was put into operation for all delivery techniques; in particular, as shown by the pre-treatment quality assurance results, it enabled accurate and safe delivery of RapidArc plans. PMID:21961830

  18. Preliminary experiments on the production of high photon energy continuum radiation from a Z-pinch at the Z accelerator

    NASA Astrophysics Data System (ADS)

    Coverdale, C. A.; Deeney, C.; Harper-Slaboscewica, V. J.; Lepell, P. D.; Velikovich, A. L.; Davis, J.; Oreshkin, V. I.

    2003-10-01

    Traditionally, the generation of multi-keV x-ray radiation from Z-pinch plasmas has focused on K-shell emissions from moderate Z materials. While this approach has worked well, it requires increasingly higher energies be coupled to each ion to produce substantial output as the photon energy increases. An alternate approach to generating multi-keV radiation, proposed in Ref. 1, utilizes lower Z materials than are necessary to generate the appropriate K-shell lines, but tailors the Z-pinch load to overheat the plasma in order to enhance the recombination radiation that is generated. Initial experiments have been performed at the Z Accelerator to evaluate the level of recombination radiation that can be generated through the tailoring of initial load radius and mass with Aluminum and Titanium wire arrays. In this paper, the results of these experiments will be presented. Measurements of yield were made for several photon energy ranges and spectra were collected to evaluate the high energy continuum. These results will be compared with simulations and theoretical predictions to evaluate the feasibility of an overheated plasma for generating higher photon energy emissions. This work is supported by the Defense Threat Reduction Agency and the Department of Energy. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under Contract DE-AC04-94AI85000. *Ktech Corporation [1] A.L. Velikovich, et. al., Phys. Plasmas 8, 4509 (2001).

  19. Operations of a spaceflight experiment to investigate plant tropisms

    NASA Astrophysics Data System (ADS)

    Kiss, John Z.; Kumar, Prem; Millar, Katherine D. L.; Edelmann, Richard E.; Correll, Melanie J.

    2009-10-01

    Plants will be an important component in bioregenerative systems for long-term missions to the Moon and Mars. Since gravity is reduced both on the Moon and Mars, studies that identify the basic mechanisms of plant growth and development in altered gravity are required to ensure successful plant production on these space colonization missions. To address these issues, we have developed a project on the International Space Station (ISS) to study the interaction between gravitropism and phototropism in Arabidopsis thaliana. These experiments were termed TROPI (for tropisms) and were performed on the European Modular Cultivation System (EMCS) in 2006. In this paper, we provide an operational summary of TROPI and preliminary results on studies of tropistic curvature of seedlings grown in space. Seed germination in TROPI was lower compared to previous space experiments, and this was likely due to extended storage in hardware for up to 8 months. Video downlinks provided an important quality check on the automated experimental time line that also was monitored with telemetry. Good quality images of seedlings were obtained, but the use of analog video tapes resulted in delays in image processing and analysis procedures. Seedlings that germinated exhibited robust phototropic curvature. Frozen plant samples were returned on three space shuttle missions, and improvements in cold stowage and handing procedures in the second and third missions resulted in quality RNA extracted from the seedlings that was used in subsequent microarray analyses. While the TROPI experiment had technical and logistical difficulties, most of the procedures worked well due to refinement during the project.

  20. Synergy Between Experiments and Simulations in Laser and Beam-Driven Plasma Acceleration and Light Sources

    NASA Astrophysics Data System (ADS)

    Mori, Warren B.

    2015-11-01

    Computer simulations have been an integral part of plasma physics research since the early 1960s. Initially, they provided the ability to confirm and test linear and nonlinear theories in one-dimension. As simulation capabilities and computational power improved, then simulations were also used to test new ideas and applications of plasmas in multi-dimensions. As progress continued, simulations were also used to model experiments. Today computer simulations of plasmas are ubiquitously used to test new theories, understand complicated nonlinear phenomenon, model the full temporal and spatial scale of experiments, simulate parameters beyond the reach of current experiments, and test the performance of new devices before large capital expenditures are made to build them. In this talk I review the progress in simulations in a particular area of plasma physics: plasma based acceleration (PBA). In PBA a short laser pulse or particle beam propagates through long regions of plasma creating plasma wave wakefields on which electrons or positrons surf to high energies. In some cases the wakefields are highly nonlinear, involve three-dimensional effects, and the trajectories of plasma particles cross making it essential that fully kinetic and three-dimensional models are used. I will show how particle-in-cell (PIC) simulations were initially used to propose the basic idea of PBA in one dimension. I will review some of the dramatic progress in the experimental demonstration of PBA and show how this progress was dramatically helped by a synergy between experiments and full-scale multi-dimensional PIC simulations. This will include a review of how the capability of PIC simulation tools has improved. I will also touch on some recent progress on improvements to PIC simulations of PBA and discuss how these improvements may push the synergy further towards real time steering of experiments and start to end modeling of key components of a future linear collider or XFEL based on PBA

  1. Design, fabrication, and operation of dished accelerator grids on a 30-cm ion thruster.

    NASA Technical Reports Server (NTRS)

    Rawlin, V. K.; Banks, B. A.; Byers, D. C.

    1972-01-01

    Several closely-spaced dished accelerator grid systems have been fabricated and tested on a 30-cm diameter mercury bombardment thruster and they appear to be a solution to the stringent requirements imposed by the near-term, high-thrust, low specific impulse electric propulsion missions. The grids were simultaneously hydroformed and then simultaneously stress relieved. The ion extraction capability and discharge chamber performance were studied as the total accelerating voltage, the ratio of net-to-total voltage, grid spacing, and dish direction were varied.

  2. Design, fabrication, and operation of dished accelerator grids on a 30-cm ion thruster

    NASA Technical Reports Server (NTRS)

    Rawlin, V. K.; Banks, B. A.; Byers, D. C.

    1972-01-01

    Several closely-space dished accelerator grid systems were fabricated and tested on a 30-cm diameter mercury bombardment thruster and they appear to be a solution to the stringent requirements imposed by the near-term, high-thrust, low specific impulse electric propulsion missions. The grids were simultaneously hydroformed and then simultaneously stress relieved. The ion extraction capability and discharge chamber performance were studied as the total accelerating voltage, the ratio of net-to-total voltage, grid spacing, and dish direction were varied.

  3. Proton acceleration by single-cycle laser pulses offers a novel monoenergetic and stable operating regime

    NASA Astrophysics Data System (ADS)

    Zhou, M. L.; Yan, X. Q.; Mourou, G.; Wheeler, J. A.; Bin, J. H.; Schreiber, J.; Tajima, T.

    2016-04-01

    Prompted by the possibility to produce high energy, single-cycle laser pulses with tens of Petawatt (PW) power, we have investigated laser-matter interactions in the few optical cycle and ultra relativistic intensity regimes. A particularly interesting instability-free regime for ion production was revealed leading to the efficient coherent generation of short (femtosecond; 10 - 15 s ) monoenergetic ion bunches with a peak energy greater than GeV. Of paramount importance, the interaction is absent of the Rayleigh Taylor Instabilities and hole boring that plague techniques such as target normal sheath acceleration and radiation pressure acceleration.

  4. Cavity digital control testing system by Simulink step operation method for TESLA linear accelerator and free electron laser

    NASA Astrophysics Data System (ADS)

    Czarski, Tomasz; Romaniuk, Ryszard S.; Pozniak, Krzysztof T.; Simrock, Stefan

    2004-07-01

    The cavity control system for the TESLA -- TeV-Energy Superconducting Linear Accelerator project is initially introduced in this paper. The FPGA -- Field Programmable Gate Array technology has been implemented for digital controller stabilizing cavity field gradient. The cavity SIMULINK model has been applied to test the hardware controller. The step operation method has been developed for testing the FPGA device coupled to the SIMULINK model of the analog real plant. The FPGA signal processing has been verified according to the required algorithm of the reference MATLAB controller. Some experimental results have been presented for different cavity operational conditions.

  5. Breakthrough: Fermilab Accelerator Technology

    ScienceCinema

    None

    2014-08-12

    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.

  6. 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.

  7. Breakthrough: Fermilab Accelerator Technology

    SciTech Connect

    2012-04-23

    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.

  8. "Smart" Magnetic Fluids Experiment Operated on the International Space Station

    NASA Technical Reports Server (NTRS)

    Agui, Juan H.; Lekan, Jack F.

    2004-01-01

    InSPACE is a microgravity fluid physics experiment that was operated on the International Space Station (ISS) in the Microgravity Science Glovebox from late March 2003 through early July 2003. (InSPACE is an acronym for Investigating the Structure of Paramagnetic Aggregates From Colloidal Emulsions.) The purpose of the experiment is to obtain fundamental data of the complex properties of an exciting class of smart materials termed magnetorheological (MR) fluids. MR fluids are suspensions, or colloids, comprised of small (micrometer-sized) superparamagnetic particles in a nonmagnetic medium. Colloids are suspensions of very small particles suspended in a liquid. (Examples of other colloids are blood, milk, and paint.) These controllable fluids can quickly transition into a nearly solid state when exposed to a magnetic field and return to their original liquid state when the magnetic field is removed. Controlling the strength of the magnetic field can control the relative stiffness of these fluids. MR fluids can be used to improve or develop new seat suspensions, robotics, clutches, airplane landing gear, and vibration damping systems. The principal investigator for InSPACE is Professor Alice P. Gast of the Massachusetts Institute of Technology (MIT). The InSPACE hardware was developed at the NASA Glenn Research Center. The InSPACE samples were delivered to the ISS in November 2002, on the Space Shuttle Endeavour, on Space Station Utilization Flight UF-2/STS113. Operations began on March 31, 2003, with the processing of three different particle size samples at multiple test parameters. This investigation focused on determining the structural organization of MR colloidal aggregates when exposed to a pulsing magnetic field. On Earth, the aggregates take the shape of footballs with spiky tips. This characteristic shape may be influenced by the pull of gravity, which causes most particles initially suspended in the fluid to sediment, (i.e., settle and collect at the

  9. Operational and troubleshooting experiences in the SST-1 cryogenic system

    NASA Astrophysics Data System (ADS)

    Mahesuria, G.; Panchal, P.; Panchal, R.; Patel, R.; Sonara, D.; Gupta, N. C.; Srikanth, G. L. N.; Christian, D.; Garg, A.; Bairagi, N.; Patel, K.; Shah, P.; Nimavat, H.; Sharma, R.; Patel, J. C.; Tank, J.; Tanna, V. L.; Pradhan, S.

    2014-01-01

    Recently, the cooldown and current charging campaign have been carried out towards the demonstration of the first successful plasma discharge in the steady state superconducting Tokomak (SST-1). The SST-1 machine consists of cable-in-conduit wound superconducting toroidal as well as poloidal coils, cooled using 1.3 kW at 4.5 K helium refrigerator -cum- liquefier (HRL) system. The cryo system provides the two-phase helium at 0.13 MPa at 4.5 K as well as forced-flow pressurized helium at 0.4 MPa and in addition to 7 g-s-1 liquefaction capacity required for the current leads and other cold mass at 4.5 K. The entire integrated cold masses having different thermo hydraulic resistances cooled with the SST-1 HRL in optimised process parameters. In order to maintain different levels of temperatures and to facilitate smooth and reliable cooldown, warm-up, normal operations as well as to handle abnormal events such as, quench or utilities failures etc., exergy efficient process are adopted for the helium refrigerator-cum-liquefier (HRL) with an installed equivalent capacity of 1.3 kW at 4.5 K. Using the HRL, the cold mass of about 40 tons is being routinely cooled down from ambient temperature to 4.5 K with an average cooldown rate of 0.75 - 1 K-h-1. Long-term cryogenic stable conditions were obtained within 15 days in the superconducting coils and their connecting feeders. Afterwards, all of the cold mass is warmed-up in a controlled manner to ambient temperature. In this paper, we report the recent operational results of the cryogenic system during the first plasma discharge in SST-1 as well as the troubleshooting experiences of the cryogenic plant related hardware.

  10. Autonomous Sciencecraft Experiment (ASE) Test Operations in 2003

    NASA Technical Reports Server (NTRS)

    Chien, S.; Davies, A. G.; Baker, V.; Castano, B.; Cichy, B.; Doggett, T.; Dohm, J. M.; Greeley, R.; Sherwood, R.; Williams, K.

    2003-01-01

    NASA has identified the development of an autonomously operating spacecraft as a necessity for an expanded program of missions exploring the Solar System. The Autonomous Sciencecraft Experiment (ASE) has been selected for flight demonstration by NASA s New Millennium Program (NMP) as part of the Space Technology 6 (ST6) mission. ASE is scheduled to fly on the US Air Force Research Laboratory (AFRL) Techsat-21 constellation in 2006. Tech- Sat-21 consists of three satellites flying in a variable-geometry formation in Earth orbit. Each satellite is equipped with X-band Synthetic Aperture Radar, yielding high spatial resolution images (approx. 3 m) of the Earth s surface. The constellation will fly at an altitude of 550 km, in a 35.4 inclination circular orbit, yielding exact repeat-track observations every 13 days. Prior to full deployment, elements of the versatile ASE spacecraft command and control software, image formation software and science processing software will be utilized and tested on two very different platforms in 2003: AirSAR and EO-1 (described below). Advantages of Autonomous Operations: ASE will demonstrate advanced autonomous science data acquisition, processing, and product downlink prioritization, as well as autonomous spacecraft command and control, and fault detection. The advantages of spacecraft autonomy are to future missions include: (a) making the best use of reduced downlink; (b) the overcoming of communication delays through decisionmaking in situ, enabling fast reaction to dynamic events; (c) an increase of science content per byte of returned data; and (d) an avoidance of return of null (no-change/no feature) datasets: if there is no change detectable between two scenes of the same target, there is no need to return the second dataset.

  11. Operational Regimes of the National Spherical Torus Experiment

    SciTech Connect

    D. Mueller; M.G. Bell; R.E. Bell; M. Bitter; T. Bigelow; P. Bonoli; M. Carter; J. Ferron; E. Fredrickson; D. Gates; L. Grisham; J.C. Hosea; D. Johnson; R. Kaita; S.M. Kaye; H. Kugel; B.P. LeBlanc; R. Maingi; R. Majeski; R. Maqueda; J. Menard; M. Ono; F. Paoletti; S. Paul; C.K. Phillips; R. Pinsker; R. Raman; S.A. Sabbagh; C.H. Skinner; V.A. Soukhanovskii; D. Stutman; D. Swain; Y. Takase; J. Wilgen; J.R. Wilson; G.A. Wurden; S. Zweben

    2002-06-03

    The National Spherical Torus Experiment (NSTX) is a proof-of-principle experiment designed to study the physics of Spherical Tori (ST), i.e., low-aspect-ratio toroidal plasmas. Important issues for ST research are whether the high-eta stability and reduced transport theoretically predicted for this configuration can be realized experimentally. In NSTX, the commissioning of a digital real-time plasma control system, the provision of flexible heating systems, and the application of wall conditioning techniques were instrumental in achieving routine operation with good confinement. NSTX has produced plasmas with R/a {approx} 0.85 m/0.68 m, A {approx} 1.25, Ip * 1.1 MA, BT = 0.3-0.45 T, k * 2.2, d * 0.5, with auxiliary heating by up to 4 MW of High Harmonic Fast Waves, and 5 MW of 80 keV D0 Neutral Beam Injection (NBI). The energy confinement time in plasmas heated by NBI has exceeded 100 ms and a toroidal beta (bT = 2m0

    /BT02, where BT0 is the central vacuum toroidal magnetic field) up to 22% has be en achieved. HHFW power of 2.3 MW has increased the electron temperature from an initial 0.4 keV to 0.9 keV both with and without producing a significant density rise in the plasma. The early application of both NBI and HHFW heating has slowed the penetration of the inductively produced plasma current, modifying the current profile and, thereby, the observed MHD stability.

  12. Fusion-neutron measurements for magnetized liner inertial fusion experiments on the Z accelerator

    DOE PAGESBeta

    Hahn, K. D.; Chandler, G. A.; Ruiz, C. L.; Cooper, G. W.; Gomez, M. R.; Slutz, S.; Sefkow, A. B.; Sinars, D. B.; Hansen, S. B.; Knapp, P. F.; et al

    2016-05-01

    Several magnetized liner inertial fusion (MagLIF) experiments have been conducted on the Z accelerator at Sandia National Laboratories since late 2013. Measurements of the primary DD (2.45 MeV) neutrons for these experiments suggest that the neutron production is thermonuclear. Primary DD yields up to 3e12 with ion temperatures ~2-3 keV have been achieved. Measurements of the secondary DT (14 MeV) neutrons indicate that the fuel is significantly magnetized. Measurements of down-scattered neutrons from the beryllium liner suggest ρRliner ~ 1g/cm2. Neutron bang times, estimated from neutron time-of-flight (nTOF) measurements, coincide with peak x-ray production. Furthermore, plans to improve and expandmore » the Z neutron diagnostic suite include neutron burn-history diagnostics, increased sensitivity and higher precision nTOF detectors, and neutron recoil-based yield and spectral measurements.« less

  13. Beam-wall interaction measurements in LLNL induction accelerator bend experiment

    NASA Astrophysics Data System (ADS)

    Molvik, A. W.; Friedman, A.; Kamin, G. W.; Sangster, T. C.; Eylon, S.; Hopkins, H. S.

    1997-11-01

    Ion-induced desorption coefficients are determined from measurements of pressure rises when an ion beam strikes a surface. These measurements are made after the first bend of 9^circ by deflecting the beam onto the stainless steel beam tube, and within a pill-box where the beam strikes a stainless steel target at an angle that can be varied from 90^circ to ~10^circ. The beam consists of 2 mA of singly-charged potassium ions at 80 keV with pulse lengths of several microsec. Data near 10^circ are relevant to near-term experiments where beam halo could strike the wall at angles of a few degrees. Data near 90^circ are relevant to ions resulting from charge exchange with a reactor driver class beam which has a space potential of the order of 100 kV. These data will aid in assessing the adequacy of the existing vacuum system when the bend experiment is upgraded to a recirculator induction accelerator.

  14. Proof-Of-Principle Experiment for Laser-Driven Acceleration of Relativistic Electrons in a Semi-Infinite Vacuum

    SciTech Connect

    Plettner, T.; Byer, R.L.; Colby, E.; Cowan, B.; Sears, C.M.S.; Spencer, J.E.; Siemann, R.H.; /SLAC

    2006-03-01

    We recently achieved the first experimental observation of laser-driven particle acceleration of relativistic electrons from a single Gaussian near-infrared laser beam in a semi-infinite vacuum. This article presents an in-depth account of key aspects of the experiment. An analysis of the transverse and longitudinal forces acting on the electron beam is included. A comparison of the observed data to the acceleration viewed as an inverse transition radiation process is presented. This is followed by a detailed description of the components of the experiment and a discussion of future measurements.

  15. AH-64 IHADSS aviator vision experiences in Operation Iraqi Freedom

    NASA Astrophysics Data System (ADS)

    Hiatt, Keith L.; Rash, Clarence E.; Harris, Eric S.; McGilberry, William H.

    2004-09-01

    Forty AH-64 Apache aviators representing a total of 8564 flight hours and 2260 combat hours during Operation Iraqi Freedom and its aftermath were surveyed for their visual experiences with the AH-64's monocular Integrated Helmet and Display Sighting System (IHADSS) helmet-mounted display in a combat environment. A major objective of this study was to determine if the frequencies of reports of visual complaints and illusions reported in the previous studies, addressing mostly benign training environments, differ in the more stressful combat environments. The most frequently reported visual complaints, both while and after flying, were visual discomfort and headache, which is consistent with previous studies. Frequencies of complaints after flying in the current study were numerically lower for all complaint types, but differences from previous studies are statistically significant only for visual discomfort and disorientation (vertigo). With the exception of "brownout/whiteout," reports of degraded visual cues in the current study were numerically lower for all types, but statistically significant only for impaired depth perception, decreased field of view, and inadvertent instrumental meteorological conditions. This study also found statistically lower reports of all static and dynamic illusions (with one exception, disorientation). This important finding is attributed to the generally flat and featureless geography present in a large portion of the Iraqi theater and to the shift in the way that the aviators use the two disparate visual inputs presented by the IHADSS monocular design (i.e., greater use of both eyes as opposed to concentrating primarily on display imagery).

  16. NSLS vacuum system operating experience conditioning and desorption yields

    SciTech Connect

    Halama, H.J.

    1991-01-01

    All straight sections in both the VUV and the X-Ray rings have been filled with various insertion devices, most of them fully operational. Beam lifetime in the VUV ring is limited by the Touschek effect to {approximately}100 minutes at 800 mA due to the small vertical beam size required by users. With no experiments running, X-Ray beam lifetime is >35 hours at 220 mA and is limited by beam gas scattering. During the past several years the U10 beam line was used to measure PSD yields from various metals to study their relative merits for light sources. These yields were also compared to those measured in X-Ray ring dipoles during initial commissioning when desorption was high. Despite the large differences in critical photon energies, agreement was quite good. Both rings are now fully conditioned and their pressures and lifetimes have reached equilibrium. Well established conditioning procedures are followed after every intervention into their vacuum systems.

  17. Operational experience with the ALICE High Level Trigger

    NASA Astrophysics Data System (ADS)

    Szostak, Artur

    2012-12-01

    The ALICE HLT is a dedicated real-time system for online event reconstruction and triggering. Its main goal is to reduce the raw data volume read from the detectors by an order of magnitude, to fit within the available data acquisition bandwidth. This is accomplished by a combination of data compression and triggering. When HLT is enabled, data is recorded only for events selected by HLT. The combination of both approaches allows for flexible data reduction strategies. Event reconstruction places a high computational load on HLT. Thus, a large dedicated computing cluster is required, comprising 248 machines, all interconnected with InfiniBand. Running a large system like HLT in production mode proves to be a challenge. During the 2010 pp and Pb-Pb data-taking period, many problems were experienced that led to a sub-optimal operational efficiency. Lessons were learned and certain crucial changes were made to the architecture and software in preparation for the 2011 Pb-Pb run, in which HLT had a vital role performing data compression for ALICE's largest detector, the TPC. An overview of the status of the HLT and experience from the 2010/2011 production runs are presented. Emphasis is given to the overall performance, showing an improved efficiency and stability in 2011 compared to 2010, attributed to the significant improvements made to the system. Further opportunities for improvement are identified and discussed.

  18. The physics of sub-critical lattices in accelerator driven hybrid systems: The MUSE experiments in the MASURCA facility

    SciTech Connect

    Chauvin, J. P.; Lebrat, J. F.; Soule, R.; Martini, M.; Jacqmin, R.; Imel, G. R.; Salvatores, M.

    1999-06-10

    Since 1991, the CEA has studied the physics of hybrid systems, involving a sub-critical reactor coupled with an accelerator. These studies have provided information on the potential of hybrid systems to transmute actinides and, long lived fission products. The potential of such a system remains to be proven, specifically in terms of the physical understanding of the different phenomena involved and their modelling, as well as in terms of experimental validation of coupled systems, sub-critical environment/accelerator. This validation must be achieved through mock-up studies of the sub-critical environments coupled to a source of external neutrons. The MUSE-4 mock-up experiment is planed at the MASURCA facility and will use an accelerator coupled to a tritium target. The great step between the generator used in the past and the accelerator will allow to increase the knowledge in hybrid physic and to decrease the experimental biases and the measurement uncertainties.

  19. Sprint Accelerations to First Base Among Major League Baseball Players With Different Years of Career Experience.

    PubMed

    Coleman, A Eugene; Amonette, William E

    2015-07-01

    The purpose of this article was to compare times to first base in Major League Baseball games to determine whether running velocity decreases to the foul line and first base among players with differing years of playing experience. From 1998 to 2012, 1,185 sprint times to first base were analyzed: 469 outfielders, 601 infielders, and 115 catchers. The players were divided into differing experience categories depending on their years of service in Major League Baseball: 1-5, 6-10, 11-15, and 16-20+ years. Velocity at the foul line and first base was compared and interval accelerations were reported. Comparisons were completed by playing position, and within left- and right-handed batters. Left-handed outfielders exhibited reduced velocities at 6-10 (p = 0.04), 11-15 (p = 0.004), and 16-20 years (p < 0.001) compared with 1-5 years; there were no statistical differences in velocity at the foul line. Right-handed outfielders exhibited significantly reduced velocities at first base in 6-10 (p = 0.002) and 11-15 years (p = 0.001); they also had a reduced velocities at the foul line in 6-10 (p = 0.004) and 11-15 years (p = 0.009). Right-handed infielders had reduced velocities at first base in 11-15 years (p < 0.001). No other differences were observed within infielders at first base or the foul line. There were no differences within the compared variables for catchers. Decreases in running velocity to first base with experience are seen in outfielders but are less prominent in infielders and catchers. Although physical capabilities for sprinting may decline with age, it is possible that through repetition more experienced players perfect the skill-related component of running to first base, thus preserving speed. PMID:25353082

  20. The LTP Experiment on LISA Pathfinder: Operational Definition of TT Gauge in Space

    NASA Astrophysics Data System (ADS)

    Armano, Michele

    2011-10-01

    The European Space Agency (ESA) and the National Aeronautics and Space Administration (NASA) are planning the Laser Interferometer Space Antenna (LISA) mission in order to detect GW. The need of accurate testing of free-fall and knowledge of noise in a space environment similar to LISA's is considered mandatory a pre-phase for the project. Therefore the LISA Pathfinder mission has been designed by ESA to fly the LISA Technology Package (LTP), aiming at testing free-fall by measuring the residual acceleration between two test-bodies in the dynamical scheme we address as "drag-free". The spectral map of the residual acceleration as function of frequency will convey information on the local noise level, thus producing a picture of the environmental working conditions for LISA itself. The thesis contains abundant material on the problem of compensating static gravity, the development of a theory of orthogonalization of reference and cross-talk for the LTP experiment. The construction of the laser detection procedure starting from GR and differential geometry arguments is carried on. Effort was put in pointing out the physical motivations for the choices made in several other papers by the author and colleagues. In this perspective the thesis is meant as a summary tool for the LTP collaboration. In the second part of the thesis we summarize our contributions for a measurement of G onboard LTP and review on possible tests of fundamental physics the mission might embody. A wide part of the thesis is now part of the LTP Operation Master Plan, describing the real science and operations onboard LISA Pathfinder. This thesis was defended on September 26th, 2006 at the University of Como, Italy.

  1. Measurement of performance using acceleration control and pulse control in simulated spacecraft docking operations

    NASA Technical Reports Server (NTRS)

    Brody, Adam R.; Ellis, Stephen R.

    1992-01-01

    Nine commercial airline pilots served as test subjects in a study to compare acceleration control with pulse control in simulated spacecraft maneuvers. Simulated remote dockings of an orbital maneuvering vehicle (OMV) to a space station were initiated from 50, 100, and 150 meters along the station's -V-bar (minus velocity vector). All unsuccessful missions were reflown. Five way mixed analysis of variance (ANOVA) with one between factor, first mode, and four within factors (mode, bloch, range, and trial) were performed on the data. Recorded performance measures included mission duration and fuel consumption along each of the three coordinate axes. Mission duration was lower with pulse mode, while delta V (fuel consumption) was lower with acceleration mode. Subjects used more fuel to travel faster with pulse mode than with acceleration mode. Mission duration, delta V, X delta V, Y delta V., and Z delta V all increased with range. Subjects commanded the OMV to 'fly' at faster rates from further distances. These higher average velocities were paid for with increased fuel consumption. Asymmetrical transfer was found in that the mode transitions could not be predicted solely from the mission duration main effect. More testing is advised to understand the manual control aspects of spaceflight maneuvers better.

  2. 42 CFR 417.413 - Qualifying condition: Operating experience and enrollment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Qualifying condition: Operating experience and... Qualifying condition: Operating experience and enrollment. (a) Condition. The HMO or CMP must demonstrate that it has operating experience and an enrolled population sufficient to provide a reasonable...

  3. Operational experience with a high speed video data acquisition system in Fermilab experiment E-687

    SciTech Connect

    Baumbaugh, A.E.; Knickerbocker, K.L.; Baumbaugh, B.; Ruchti, R.

    1987-10-21

    Operation of a high speed, triggerable, Video Data Acquisition System (VDAS) including a hardware data compactor and a 16 megabyte First-In-First-Out buffer memory (FIFO) will be discussed. Active target imaging techniques for High Energy Physics are described and preliminary experimental data is reported.. The hardware architecture for the imaging system and experiment will be discussed as well as other applications for the imaging system. Data rates for the compactor is over 30 megabytes/sec and the FIFO has been run at 100 megabytes/sec. The system can be operated at standard video rates or at any rate up to 30 million pixels/second. 7 refs., 3 figs.

  4. [Evoked potentials in intracranial operations: current status and our experiences].

    PubMed

    Nau, H E; Hess, W; Pohlen, G; Marggraf, G; Rimpel, J

    1987-03-01

    Intraoperative neuromonitoring, especially evoked potential monitoring, has gained interest in recent years for both the anesthesiologist evaluating cerebral function and the neurosurgeon wishing to avoid neuronal lesions during intracranial operations. Before evoked potential monitoring can be introduced as a routine method of intraoperative management, experience with this method particularly in intensive care units, is imperative. We recorded evoked potentials with the Compact Four (Nicolet) and Basis 8000 (Schwarzer Picker International) computer systems. Preoperative derivations should be done with the same apparatus used intraoperatively and parameters of peri- and intraoperative derivations should not be changed. The patient's head must be fixed in a Mayfield clamp in order to avoid artefacts during trepanation. The possible artefacts due to apparatus, patient, or anesthesia are summarized in the tables. The derivations of evoked potentials should be supervised by a person who is not involved in the anesthesia or the surgical procedure; this condition may change in the future with full automatization of the recording technique and alarms. Good communication between surgeon, anesthesiologist, and neurophysiological assistant is a prerequisite. The modality is chosen in accordance with the affected neuronal system: visual-evoked potential (VEP) monitoring in the management of processes affecting the visual pathway, brain stem auditory-(BAER) and somatosensory-evoked potential (SSEP) monitoring in lesions affecting these pathways, in particular space-occupying lesions of the posterior fossa. VEP monitoring may be useful, but we observed alterations of the responses without changes in the level of anesthesia or manipulation of the visual pathways. In space-occupying processes of the cerebellopontine angle, BAER could not be developed in nearly all cases because the large underlying tumor had caused the disappearance of waves II-V. In these cases SSEP monitoring

  5. Model experiment of cosmic ray acceleration due to an incoherent wakefield induced by an intense laser pulse

    SciTech Connect

    Kuramitsu, Y.; Sakawa, Y.; Takeda, K.; Tampo, M.; Takabe, H.; Nakanii, N.; Kondo, K.; Tsuji, K.; Kimura, K.; Fukumochi, S.; Kashihara, M.; Tanimoto, T.; Nakamura, H.; Ishikura, T.; Kodama, R.; Mima, K.; Tanaka, K. A.; Mori, Y.; Miura, E.; Kitagawa, Y.

    2011-01-15

    The first report on a model experiment of cosmic ray acceleration by using intense laser pulses is presented. Large amplitude light waves are considered to be excited in the upstream regions of relativistic astrophysical shocks and the wakefield acceleration of cosmic rays can take place. By substituting an intense laser pulse for the large amplitude light waves, such shock environments were modeled in a laboratory plasma. A plasma tube, which is created by imploding a hollow polystyrene cylinder, was irradiated by an intense laser pulse. Nonthermal electrons were generated by the wakefield acceleration and the energy distribution functions of the electrons have a power-law component with an index of {approx}2. The maximum attainable energy of the electrons in the experiment is discussed by a simple analytic model. In the incoherent wakefield the maximum energy can be much larger than one in the coherent field due to the momentum space diffusion or the energy diffusion of electrons.

  6. Two Channel Dielectric-Lined Rectangular High Transformer Ratio Accelerator Structure Experiment

    SciTech Connect

    Shchelkunov, S. V.; LaPointe, M. A.; Hirshfield, J. L.; Marshall, T. C.; Sotnikov, G.; Gai, Wei; Conde, M.; Power, J.; Mihalcea, D.

    2010-11-04

    Current status of a two-channel cm-scale rectangular dielectric lined wakefield accelerator structure is described. This structure is installed at the Argonne Wakefield Accelerator facility (AWA), and is presently being evaluated. The device has a transformer ratio of {approx}12.5:1. When driven by a {approx}50 nC single drive bunch it is expected to obtain {approx}6 MV/m acceleration gradient. Related issues are discussed.

  7. Comparison of Acceleration Techniques for Selected Low-Level Bioinformatics Operations

    PubMed Central

    Langenkämper, Daniel; Jakobi, Tobias; Feld, Dustin; Jelonek, Lukas; Goesmann, Alexander; Nattkemper, Tim W.

    2016-01-01

    Within the recent years clock rates of modern processors stagnated while the demand for computing power continued to grow. This applied particularly for the fields of life sciences and bioinformatics, where new technologies keep on creating rapidly growing piles of raw data with increasing speed. The number of cores per processor increased in an attempt to compensate for slight increments of clock rates. This technological shift demands changes in software development, especially in the field of high performance computing where parallelization techniques are gaining in importance due to the pressing issue of large sized datasets generated by e.g., modern genomics. This paper presents an overview of state-of-the-art manual and automatic acceleration techniques and lists some applications employing these in different areas of sequence informatics. Furthermore, we provide examples for automatic acceleration of two use cases to show typical problems and gains of transforming a serial application to a parallel one. The paper should aid the reader in deciding for a certain techniques for the problem at hand. We compare four different state-of-the-art automatic acceleration approaches (OpenMP, PluTo-SICA, PPCG, and OpenACC). Their performance as well as their applicability for selected use cases is discussed. While optimizations targeting the CPU worked better in the complex k-mer use case, optimizers for Graphics Processing Units (GPUs) performed better in the matrix multiplication example. But performance is only superior at a certain problem size due to data migration overhead. We show that automatic code parallelization is feasible with current compiler software and yields significant increases in execution speed. Automatic optimizers for CPU are mature and usually no additional manual adjustment is required. In contrast, some automatic parallelizers targeting GPUs still lack maturity and are limited to simple statements and structures. PMID:26904094

  8. Comparison of Acceleration Techniques for Selected Low-Level Bioinformatics Operations.

    PubMed

    Langenkämper, Daniel; Jakobi, Tobias; Feld, Dustin; Jelonek, Lukas; Goesmann, Alexander; Nattkemper, Tim W

    2016-01-01

    Within the recent years clock rates of modern processors stagnated while the demand for computing power continued to grow. This applied particularly for the fields of life sciences and bioinformatics, where new technologies keep on creating rapidly growing piles of raw data with increasing speed. The number of cores per processor increased in an attempt to compensate for slight increments of clock rates. This technological shift demands changes in software development, especially in the field of high performance computing where parallelization techniques are gaining in importance due to the pressing issue of large sized datasets generated by e.g., modern genomics. This paper presents an overview of state-of-the-art manual and automatic acceleration techniques and lists some applications employing these in different areas of sequence informatics. Furthermore, we provide examples for automatic acceleration of two use cases to show typical problems and gains of transforming a serial application to a parallel one. The paper should aid the reader in deciding for a certain techniques for the problem at hand. We compare four different state-of-the-art automatic acceleration approaches (OpenMP, PluTo-SICA, PPCG, and OpenACC). Their performance as well as their applicability for selected use cases is discussed. While optimizations targeting the CPU worked better in the complex k-mer use case, optimizers for Graphics Processing Units (GPUs) performed better in the matrix multiplication example. But performance is only superior at a certain problem size due to data migration overhead. We show that automatic code parallelization is feasible with current compiler software and yields significant increases in execution speed. Automatic optimizers for CPU are mature and usually no additional manual adjustment is required. In contrast, some automatic parallelizers targeting GPUs still lack maturity and are limited to simple statements and structures. PMID:26904094

  9. Shock experiments and numerical simulations on low energy portable electrically exploding foil accelerators

    NASA Astrophysics Data System (ADS)

    Saxena, A. K.; Kaushik, T. C.; Gupta, Satish C.

    2010-03-01

    Two low energy (1.6 and 8 kJ) portable electrically exploding foil accelerators are developed for moderately high pressure shock studies at small laboratory scale. Projectile velocities up to 4.0 km/s have been measured on Kapton flyers of thickness 125 μm and diameter 8 mm, using an in-house developed Fabry-Pérot velocimeter. An asymmetric tilt of typically few milliradians has been measured in flyers using fiber optic technique. High pressure impact experiments have been carried out on tantalum, and aluminum targets up to pressures of 27 and 18 GPa, respectively. Peak particle velocities at the target-glass interface as measured by Fabry-Pérot velocimeter have been found in good agreement with the reported equation of state data. A one-dimensional hydrodynamic code based on realistic models of equation of state and electrical resistivity has been developed to numerically simulate the flyer velocity profiles. The developed numerical scheme is validated against experimental and simulation data reported in literature on such systems. Numerically computed flyer velocity profiles and final flyer velocities have been found in close agreement with the previously reported experimental results with a significant improvement over reported magnetohydrodynamic simulations. Numerical modeling of low energy systems reported here predicts flyer velocity profiles higher than experimental values, indicating possibility of further improvement to achieve higher shock pressures.

  10. Nike Experiments on Acceleration of Planar Targets Stabilized with a Short Spike Pulse^1

    NASA Astrophysics Data System (ADS)

    Weaver, J. L.; Velikovich, A. L.; Metzler, N.; Aglitskiy, Y.; Oh, J.; Mostovych, A. N.; Gardner, J. H.

    2005-10-01

    Theoretical work has shown that a low energy spike pulse in front of the drive laser pulse can help mitigate the growth of hydrodynamic instabilities in targets for inertial confinement fusion.[1]^ While other experiments [2] used higher spike pulse energies, this study reports the influence of a lower energy spike and longer spike-main pulse delay on the acceleration of planar CH targets. Time evolution of preimposed sinusoidal ripples on the target surface was observed using a monochromatic x-ray imaging system. Delayed onset and/or suppression of mode growth was found for the spike prepulse shots compared to those with a low intensity foot, in good agreement with predictions from FAST2D simulations. The propagation velocity of the decaying shock wave from the spike pulse was measured with VISAR and was also in good agreement with an analytical prediction.[3] [1] Metzler et al., Phys. Plasmas 6, 3283 (1999); 9, 5050 (2002); 10, 1897 (2003);Goncharov et al., Phys. Plasmas 10, 1906 (2003) ;Betti et al., Phys Plamas 12, 042703 (2005) ;[2]Knauer et al., Phys. Plasmas 12, 056306 (2005) ; [3]Velikovich et al., Phys. Plasmas 10, 3270 (2003). ^1Work supported by U. S. Department of Energy

  11. Accelerated Aging Experiments for Prognostics of Damage Growth in Composite Materials

    NASA Technical Reports Server (NTRS)

    Saxena, Abhinav; Goebel, Kai Frank; Larrosa, Cecilia C.; Janapati, Vishnuvardhan; Roy, Surajit; Chang, Fu-Kuo

    2011-01-01

    Composite structures are gaining importance for use in the aerospace industry. Compared to metallic structures their behavior is less well understood. This lack of understanding may pose constraints on their use. One possible way to deal with some of the risks associated with potential failure is to perform in-situ monitoring to detect precursors of failures. Prognostic algorithms can be used to predict impending failures. They require large amounts of training data to build and tune damage model for making useful predictions. One of the key aspects is to get confirmatory feedback from data as damage progresses. These kinds of data are rarely available from actual systems. The next possible resource to collect such data is an accelerated aging platform. To that end this paper describes a fatigue cycling experiment with the goal to stress carbon-carbon composite coupons with various layups. Piezoelectric disc sensors were used to periodically interrogate the system. Analysis showed distinct differences in the signatures of growing failures between data collected at conditions. Periodic X-radiographs were taken to assess the damage ground truth. Results after signal processing showed clear trends of damage growth that were correlated to damage assessed from the X-ray images.

  12. Numerical simulations of recent proton acceleration experiments with sub-100 TW laser systems

    NASA Astrophysics Data System (ADS)

    Sinigardi, Stefano

    2016-09-01

    Recent experiments carried out at the Italian National Research Center, National Optics Institute Department in Pisa, are showing interesting results regarding maximum proton energies achievable with sub-100 TW laser systems. While laser systems are being continuously upgraded in laboratories around the world, at the same time a new trend on stabilizing and making ion acceleration results reproducible is growing in importance. Almost all applications require a beam with fixed performance, so that the energy spectrum and the total charge exhibit moderate shot to shot variations. This result is surely far from being achieved, but many paths are being explored in order to reach it. Some of the reasons for this variability come from fluctuations in laser intensity and focusing, due to optics instability. Other variation sources come from small differences in the target structure. The target structure can vary substantially, when it is impacted by the main pulse, due to the prepulse duration and intensity, the shape of the main pulse and the total energy deposited. In order to qualitatively describe the prepulse effect, we will present a two dimensional parametric scan of its relevant parameters. A single case is also analyzed with a full three dimensional simulation, obtaining reasonable agreement between the numerical and the experimental energy spectrum.

  13. Accelerating phylogenetics computing on the desktop: experiments with executing UPGMA in programmable logic.

    PubMed

    Davis, J P; Akella, S; Waddell, P H

    2004-01-01

    Having greater computational power on the desktop for processing taxa data sets has been a dream of biologists/statisticians involved in phylogenetics data analysis. Many existing algorithms have been highly optimized-one example being Felsenstein's PHYLIP code, written in C, for UPGMA and neighbor joining algorithms. However, the ability to process more than a few tens of taxa in a reasonable amount of time using conventional computers has not yielded a satisfactory speedup in data processing, making it difficult for phylogenetics practitioners to quickly explore data sets-such as might be done from a laptop computer. We discuss the application of custom computing techniques to phylogenetics. In particular, we apply this technology to speed up UPGMA algorithm execution by a factor of a hundred, against that of PHYLIP code running on the same PC. We report on these experiments and discuss how custom computing techniques can be used to not only accelerate phylogenetics algorithm performance on the desktop, but also on larger, high-performance computing engines, thus enabling the high-speed processing of data sets involving thousands of taxa. PMID:17270875

  14. Absolute reactivity calibration of accelerator-driven systems after RACE-T experiments

    SciTech Connect

    Jammes, C. C.; Geslot, B.

    2006-07-01

    The RACE-T experiments that were held in november 2005 in the ENEA-Casaccia research center near Rome allowed us to improve our knowledge of the experimental techniques for absolute reactivity calibration at either startup or shutdown phases of accelerator-driven systems. Various experimental techniques for assessing a subcritical level were inter-compared through three different subcritical configurations SC0, SC2 and SC3, about -0.5, -3 and -6 dollars, respectively. The area-ratio method based of the use of a pulsed neutron source appears as the most performing. When the reactivity estimate is expressed in dollar unit, the uncertainties obtained with the area-ratio method were less than 1% for any subcritical configuration. The sensitivity to measurement location was about slightly more than 1% and always less than 4%. Finally, it is noteworthy that the source jerk technique using a transient caused by the pulsed neutron source shutdown provides results in good agreement with those obtained from the area-ratio technique. (authors)

  15. Ice Target and Gas Target Experiments in the IMPACT Dust Accelerator

    NASA Astrophysics Data System (ADS)

    Munsat, T. L.; Collette, A.; Dee, R.; Gruen, E.; Horanyi, M.; James, D.; Janches, D.; Kempf, S.; Plane, J. M. C.; Shu, A. J.; Simolka, J.; Sternovsky, Z.; Thomas, E.

    2014-12-01

    The dust accelerator facility at the SSERVI Institute for Modeling Plasma, Atmospheres, and Cosmic Dust (IMPACT) is presently implementing two major target upgrades: a cryogenic ice target and a high-pressure gas target. The ice target consists of a LN2 cryogenic system connected to both a water-ice deposition system as well as a movable freezer/holder for a pre-mixed liquid cartridge. Planned experiments include the bombardment of a variety of frozen targets and simulated ice/regolith mixtures, and the assessment of all impact products (solid ejecta, gas, plasma) as well as spectroscopy of both the impact-produced light flashes and the reflected spectra (UV, visible, IR). Such measurements are highly relevant to both physical and chemical surface modification of airless bodies due to micrometeoroid impacts. The gas target consists of a differentially pumped chamber kept at moderate background pressures, such that high-velocity (~10 km/s) micrometeoroids are completely ablated within 10's of cm (i.e. within the measurement chamber). The chamber is configured with segmented electrodes to perform a spatially-resolved measurement of charge production during ablation, and localized light-collection optics enable an assessment of the light production (luminous efficiency). Such studies are critical to the understanding of past and future ground-based measurements of meteor ablation in Earth's atmosphere, which in turn can potentially provide the best estimates of the interplanetary dust particle flux.

  16. New experiments selected for 1980 operational shuttle flight

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Experiments selected for NASA's Long Duration Exposure Facility mission are described. Technical areas represented by the experiments include materials, thermal control coatings, detectors, power, micrometeoroids, electronics, lubrication, optics, and space debris detection.

  17. Acceleration of convergence and spectrum transformation of implicit finite difference operators associated with Navier-Stokes equations

    NASA Technical Reports Server (NTRS)

    Saleem, M.; Pulliam, T.; Cheer, A. Y.

    1993-01-01

    Implicit difference operator spectra are presently computed by applying eigensystem analysis techniques to finite-difference formulations of 2D Euler and Navier-Stokes equations, and attention is given to these iterative methods' convergence and stability characteristics by taking into account the effects of grid geometry, time-step, numerical viscosity, and boundary conditions. On the basis of the eigenvalue distributions for various flow configurations, the feasibility of applying such convergence-acceleration techniques as eigenvalue annihilation and relaxation is discussed. Spectrum-shifting is applied to NASA-Ames' ARC2D flow code, achieving a 20-33 percent efficiency.

  18. Lead-bismuth eutectic as advanced reactor collant : operational experience

    SciTech Connect

    Woloshun, K. A.; Watts, V.; Li, N.

    2004-01-01

    Some proposed advanced reactor concepts would be cooled by lead or lead-bismuth eutectic (LBE). An LBE test loop was designed and built at Los Alamos to develop the engineering and materials technology necessary to successfully implement LBE as a coolant (Fig. 1). Operational since December 2001, this test loop has been used to develop and demonstrate safe operation, oxygen concentration and metal corrosion control, instrumentation, thermal-hydraulic performance of heat exchangers and recuperators, and free convection and forced pumping. This paper discusses the technology development and lessons learned from the operation of this facility. A LBE test loop has been operational since December 2001. Using procedures, training, and engineering controls, this loop has operated without an accident. Continuous improvements in operation procedures and instrumentation over these years have resulted in a facility of high reliability, providing the groundwork for the use of LBE as a reactor coolant for temperatures up to 550 C.

  19. Operational Experiences Tuning the ATF2 Final Focus Optics Towards Obtaining a 37nm Electron Beam IP Spot Size

    SciTech Connect

    White, Glen; Seryi, Andrei; Woodley, Mark; Bai, Sha; Bambade, Philip; Renier, Yves; Bolzon, Benoit; Kamiya, Yoshio; Komamiya, Sachio; Oroku, Masahiro; Yamaguchi, Yohei; Yamanaka, Takashi; Kubo, Kiyoshi; Kuroda, Shigeru; Okugi, Toshiyuki; Tauchi, Toshiaki; Marin, Eduardo; /CERN

    2012-07-06

    The primary aim of the ATF2 research accelerator is to test a scaled version of the final focus optics planned for use in next-generation linear lepton colliders. ATF2 consists of a 1.3 GeV linac, damping ring providing low-emittance electron beams (< 12pm in the vertical plane), extraction line and final focus optics. The design details of the final focus optics and implementation at ATF2 are presented elsewhere. The ATF2 accelerator is currently being commissioned, with a staged approach to achieving the design IP spot size. It is expected that as we implement more demanding optics and reduce the vertical beta function at the IP, the tuning becomes more difficult and takes longer. We present here a description of the implementation of the tuning procedures and describe operational experiences and performances.

  20. Operating experience at the Shamokin Culm burning steam generation plant

    SciTech Connect

    Bender, P.A.; Laukaitis, J.F.; Lockman, H.W.; Samela, D.; Smith, W.G.; Tsoumpas, G.

    1983-06-01

    After 9200 hours of operation it can be concluded that low grade anthracite culm refuse fuel can be properly combusted in a fluidized-bed boiler. The Shamokin Culm Burning Steam Generation Plant has demonstrated environmental compliance while operating over a wide range of operational variables. As changes in equipment and materials are implemented and other fuels are combusted, it is expected that a further demonstration of the Plant's capabilities will be realized.

  1. Operational experience with the SLD CRID at the SLC

    NASA Astrophysics Data System (ADS)

    Abe, K.; Aston, D.; Baird, K.; Baltay, C.; Ben-David, R.; Bienz, T.; Caldwell, D. O.; Cavalli-Sforza, M.; Coller, J.; Coyne, D.; Dima, M.; d'Oliveira, A.; Hallewell, G.; Hasegawa, Y.; Huber, J.; Iwasaki, Y.; Jacques, P.; Johnson, R. A.; Kalelkar, M.; Kawahara, H.; Leith, D. W. G. S.; Liu, X.; Lu, A.; Manly, S.; Meadows, B.; Müller, G.; Muller, D.; Nagamine, T.; Narita, S.; Nussbaum, M.; Pavel, T. J.; Plano, R.; Ratcliff, B.; Rensing, P.; Sen, S.; Shank, J. T.; Shapiro, S.; Simopoulos, C.; Snyder, J.; Stamer, P.; Suekane, F.; Turk, J.; Va'vra, J.; Whitaker, J. S.; Williams, D. A.; Williams, S. H.; Willocq, S.; Wilson, R. J.; Word, G.; Yellin, S.; Yuta, H.

    1996-02-01

    We highlight some problems encountered and lessons learned in obtaining stable operation of the SLD CRID for the past four years. During the 1994-1995 run of the SLC, we achieved stable operation of liquid (C 6F 14) and gas ( {85% C 5F 12}/{15% N 2}) radiators with good UV transparency, and we regularly operate the TPCs with excellent drift lifetimes and good single photo-electron detection efficiency.

  2. Students' Perceptions of Their Experiences from within Acceleration Programs in Mathematics

    ERIC Educational Resources Information Center

    Rawlins, Peter

    2004-01-01

    This article reports on the findings of a research project examining participant students' points of view on accelerated programs in mathematics from four state secondary schools in New Zealand. The four participant schools in this research offered a variety of different acceleration designs and philosophies and were different in size location,…

  3. "DIANA" - A New, Deep-Underground Accelerator Facility for Astrophysics Experiments

    SciTech Connect

    Leitner, M.; Leitner, D.; Lemut, A.; Vetter, P.; Wiescher, M.

    2009-05-28

    The DIANA project (Dakota Ion Accelerators for Nuclear Astrophysics) is a collaboration between the University of Notre Dame, University of North Carolina, Western Michigan University, and Lawrence Berkeley National Laboratory to build a nuclear astrophysics accelerator facility 1.4 km below ground. DIANA is part of the US proposal DUSEL (Deep Underground Science and Engineering Laboratory) to establish a cross-disciplinary underground laboratory in the former gold mine of Homestake in South Dakota, USA. DIANA would consist of two high-current accelerators, a 30 to 400 kV variable, high-voltage platform, and a second, dynamitron accelerator with a voltage range of 350 kV to 3 MV. As a unique feature, both accelerators are planned to be equipped with either high-current microwave ion sources or multi-charged ECR ion sources producing ions from protons to oxygen. Electrostatic quadrupole transport elements will be incorporated in the dynamitron high voltage column. Compared to current astrophysics facilities, DIANA could increase the available beam densities on target by magnitudes: up to 100 mA on the low energy accelerator and several mA on the high energy accelerator. An integral part of the DIANA project is the development of a high-density super-sonic gas-jet target which can handle these anticipated beam powers. The paper will explain the main components of the DIANA accelerators and their beam transport lines and will discuss related technical challenges.

  4. Accelerating progress toward operational excellence of fossil energy plants with CO2 capture

    SciTech Connect

    Zitney, S.; Liese, E.; Mahapatra, P.; Turton, R. Bhattacharyya, D.

    2012-01-01

    To address challenges in attaining operational excellence for clean energy plants, the National Energy Technology Laboratory has launched a world-class facility for Advanced Virtual Energy Simulation Training And Research (AVESTARTM). The AVESTAR Center brings together state-of-the-art, real-time, high-fidelity dynamic simulators with operator training systems and 3D virtual immersive training systems into an integrated energy plant and control room environment. This paper will highlight the AVESTAR Center simulators, facilities, and comprehensive training, education, and research programs focused on the operation and control of an integrated gasification combined cycle power plant (IGCC) with carbon dioxide capture.

  5. Technician support for operation and maintenance of large fusion experiments: the tandem mirror experiment upgrade (TMX-U) approach

    SciTech Connect

    Mattson, G.E.

    1983-12-01

    As experiments continue to grow in size and complexity, a few technicians will no longer be able to maintain and operate the complete experiment. Specialization is becoming the norm. Subsystems are becoming very large and complex, requiring a great deal of experience and training for technicians to become qualified maintenance/operation personnel. Formal in-house and off-site programs supplement on-the-job training to fulfill the qualification criteria. This paper presents the Tandem Mirror Experiment-Upgrade (TMX-U) approach to manpower staffing, some problems encountered, possible improvements, and safety considerations for the successful operation of a large experimental facility.

  6. Remotely Operated Vehicles under sea ice - Experiences and results from five years of polar operations

    NASA Astrophysics Data System (ADS)

    Katlein, Christian; Arndt, Stefanie; Lange, Benjamin; Belter, Hans Jakob; Schiller, Martin; Nicolaus, Marcel

    2016-04-01

    The availability of advanced robotic technologies to the Earth Science community has largely increased in the last decade. Remotely operated vehicles (ROV) enable spatially extensive scientific investigations underneath the sea ice of the polar oceans, covering a larger range and longer diving times than divers with significantly lower risks. Here we present our experiences and scientific results acquired from ROV operations during the last five years in the Arctic and Antarctic sea ice region. Working under the sea ice means to have all obstacles and investigated objects above the vehicle, and thus changes several paradigms of ROV operations as compared to blue water applications. Observations of downwelling spectral irradiance and radiance allow a characterization of the optical properties of sea ice and the spatial variability of the energy partitioning across the atmosphere-ice-ocean boundary. Our results show that the decreasing thickness and age of the sea ice have led to a significant increase in light transmission during summer over the last three decades. Spatially extensive measurements from ROV surveys generally provide more information on the light field variability than single spot measurements. The large number of sampled ice conditions during five cruises with the German research icebreaker RV Polarstern allows for the investigations of the seasonal evolution of light transmittance. Both, measurements of hyperspectral light transmittance through sea ice, as well as classification of upward-looking camera images were used to investigate the spatial distribution of ice-algal biomass. Buoyant ice-algal aggregates were found to be positioned in the stretches of level ice, rather than pressure ridges due to a physical interaction of aggregate-buoyancy and under-ice currents. Synchronous measurements of sea ice thickness by upward looking sonar provides crucial additional information to put light-transmittance and biological observations into context

  7. The Conversion and operation of the Cornell electron storage ring as a test accelerator (cesrta) for damping rings research and development

    SciTech Connect

    Palmer, M.A.; Alexander, J.; Byrd, J.; Celata, C.M.; Corlett, J.; De Santis, S.; Furman, M.; Jackson, A.; Kraft, R.; Munson, D.; Penn, G.; Plate, D.; Rawlins, A.; Venturini, M.; Zisman, M.; Billing, M.; Calvey, J.; Chapman, S.; Codner, G.; Conolly, C.; Crittenden, J.; Dobbins, J.; Dugan, G.; Fontes, E.; Forster, M.; Gallagher, R.; Gray, S.; Greenwald, S.; Hartill, D.; Hopkins, W.; Kandaswamy, J.; Kreinick, D.; Li, Y.; Liu, X.; Livezey, J.; Lyndaker, A.; Medjidzade, V.; Meller, R.; Peck, S.; Peterson, D.; Rendina, M.; Revesz, P.; Rice, D.; Rider, N.; Rubin, D.; Sagan, D.; Savino, J.; Seeley, R.; Sexton, J.; Shanks, J.; Sikora, J.; Smolenski, K.; Strohman, C.; Temnykh, A.; tigner, M.; Whitney, W.; Williams, H.; Vishniakou, S.; Wilkens, T.; Harkay, K.; Holtzapple, R.; Smith, E.; Jones, J.; Wolski, A.; He, Y.; Ross, M.; Tan, C.Y.; Zwaska, R.; Flanagan, J.; Jain, P.; Kanazawa, K.; Ohmi, K.; Sakai, H.; Shibata, K.; Suetsugu, Y.; Kharakh, D.; Pivi, M.; Wang, L.

    2009-05-01

    In March of 2008, the Cornell Electron Storage Ring (CESR) concluded twenty eight years of colliding beam operations for the CLEO high energy physics experiment. We have reconfigured CESR as an ultra low emittance damping ring for use as a test accelerator (CesrTA) for International Linear Collider (ILC) damping ring R&D. The primary goals of the CesrTA program are to achieve a beam emittance approaching that of the ILC Damping Rings with a positron beam, to investigate the interaction of the electron cloud with both low emittance positron and electron beams, to explore methods to suppress the electron cloud, and to develop suitable advanced instrumentation required for these experimental studies (in particular a fast x-ray beam size monitor capable of single pass measurements of individual bunches). We report on progress with the CESR conversion activities, the status and schedule for the experimental program, and the first experimental results that have been obtained.

  8. The Coronal Physics Investigator (cpi) Experiment For Iss: A New Vision For Understanding Solar Wind Acceleration

    NASA Astrophysics Data System (ADS)

    Raymond, John C.; Janzen, P. H.; Kohl, J. L.; Reisenfeld, D. B.; Chandran, B. D. G.; Cranmer, S. R.; Forbes, T. G.; Isenberg, P. A.; Panasyuk, A. V.; van Ballegooijen, A. A.

    2011-05-01

    We propose an Explorer Mission of Opportunity program to develop and operate a large-aperture ultraviolet coronagraph spectrometer called the Coronal Physics Investigator (CPI) as an attached International Space Station (ISS) payload. The primary goal of this program is to identify and characterize the physical processes that heat and accelerate the primary and secondary components of the fast and slow solar wind. Also, CPI can make key measurements needed to understand CMEs. CPI is dedicated to high spectral resolution measurements of the off-limb extended corona with far better stray light suppression than can be achieved by a conventional instrument. UVCS/SOHO allowed us to identify what additional measurements need to be made to answer the fundamental questions about how solar wind streams are produced, and CPI's next-generation capabilities were designed specifically to make those measurements. Compared to previous instruments, CPI provides unprecedented sensitivity, a wavelength range extending from 25.7 to 126 nm, higher temporal resolution, and the capability to measure line profiles of He II, N V, Ne VII, Ne VIII, Si VIII, S IX, Ar VIII, Ca IX, and Fe X, never before seen in coronal holes above 1.3 solar radii. CPI will constrain the properties and effects of coronal MHD waves by (1) observing many ions over a large range of charge and mass,(2) providing simultaneous measurements of proton and electron temperatures to probe turbulent dissipation mechanisms, and (3) measuring amplitudes of low-frequency compressive fluctuations. CPI is an internally occulted ultraviolet coronagraph that provides the required high sensitivity without the need for a deployable boom, and with all technically mature hardware including an ICCD detector. A highly experienced Explorer and ISS contractor, L-3 Com Integrated Optical Systems and Com Systems East will provide the tracking and pointing system as well as the instrument, and the integration to the ISS.

  9. Experiments of interest to nuclear astrophysics using 17F, 18F and 56NI beams from the ATLAS accelerator

    SciTech Connect

    Rehm, K.E.

    1997-12-31

    First experiments with radioactive beams of 17F, 18F and 56Ni have been performed at the superconducting accelerator ATLAS at Argonne National laboratory. The experiments address several questions related to the hot CNO cycle and the breakout into the rp process, in particular the production of 19Ne via the 18F(p,gamma) and of 17F via the 14O(4He,p) reactions. The beams were produced by using either the two-accelerator method (18F, 56Ni) or (for 17F) by bombarding a hydrogen (deuterium) target with 17O or 16O, respectively. Special high-efficiency detection techniques were developed to perform experiments with low beam intensities and sometimes considerable isobar impurities. Planned measurements with other radioactive ion beams will be discussed.

  10. Beryllium liner implosion experiments on the Z accelerator in preparation for Magnetized Liner Inertial Fusion (MagLIF)*

    NASA Astrophysics Data System (ADS)

    McBride, Ryan D.

    2012-10-01

    Magnetized Liner Inertial Fusion (MagLIF) [1] is a concept that involves using a pulsed electrical current to implode an initially-solid, cylindrical metal tube (liner) filled with preheated and magnetized fusion fuel. One- and two-dimensional simulations predict that if sufficient liner integrity can be maintained throughout the implosion, then significant fusion yield (>100 kJ) is possible on the 25-MA, 100-ns Z accelerator. The greatest threat to the liner integrity is the Magneto-Rayleigh-Taylor (MRT) instability, which first develops on the outer liner surface, and then works its way inward toward the inner surface throughout the implosion. Two-dimensional simulations predict that a thick liner, with Router/δR=6, should be robust enough to keep the MRT instability from overly disrupting the fusion burn at stagnation. This talk will present the first experiments designed to study a thick, MagLIF-relevant liner implosion through to stagnation on Z [2]. The use of beryllium for the liner material enabled us to obtain penetrating monochromatic (6151±0.5 eV) radiographs that reveal information about the entire volume of the imploding liner. This talk will also discuss experiments that investigated Z's pulse-shaping capabilities to either shock- or shocklessly-compress the imploding liners [3], as well as our most recent experiments that used 2-micron-thick aluminum sleeves to provide high-contrast tracers for the positions and states of the inner surfaces of the imploding beryllium liners. The radiography data to be presented provide stringent constraints on the simulation tools used by the broader high energy density physics and inertial confinement fusion communities, where quantitative areal density measurements, particularly of convergent fusion targets, are relatively scarce. We will also present power-flow tests of the MagLIF load hardware as well as new micro-B-dot measurements of the azimuthal drive magnetic field that penetrates the initially vacuum

  11. Design reuse experience of space and hazardous operations robots

    NASA Technical Reports Server (NTRS)

    Oneil, P. Graham

    1994-01-01

    A comparison of design drivers for space and hazardous nuclear waste operating robots details similarities and differences in operations, performance and environmental parameters for these critical environments. The similarities are exploited to provide low risk system components based on reuse principles and design knowledge. Risk reduction techniques are used for bridging areas of significant differences. As an example, risk reduction of a new sensor design for nuclear environment operations is employed to provide upgradeable replacement units in a reusable architecture for significantly higher levels of radiation.

  12. Planned High-gradient Flat-beam-driven Dielectric Wakefield Experiments at the Fermilab’s Advanced Superconducting Test Accelerator

    SciTech Connect

    Lemery, Francois; Mihalcea, Daniel; Piot, Philippe; Zhu, Jun

    2014-07-01

    In beam driven dielectric wakefield acceleration (DWA), high-gradient short-wavelength accelerating fields are generally achieved by employing dielectric-lined waveguides (DLWs)  with small aperture which constraints the beam sizes. In this paper we investigate the possibility of using a low-energy (50-MeV) flat beams to induce high-gradient wakes in a slab-symmetric DLW. We demonstrate via numerical simulations the possibility to produce axial electric field with peak amplitude close to 0.5 GV/m. Our studies are carried out using the Fermilab's Advanced Superconducting Test Accelerator (ASTA) photoinjector beamline. We finally discuss a possible experiment that could be performed in the ASTA photoinjector and eventually at higher energies.  

  13. Operations

    ERIC Educational Resources Information Center

    Wilkins, Jesse L. M.; Norton, Anderson; Boyce, Steven J.

    2013-01-01

    Previous research has documented schemes and operations that undergird students' understanding of fractions. This prior research was based, in large part, on small-group teaching experiments. However, written assessments are needed in order for teachers and researchers to assess students' ways of operating on a whole-class scale. In this…

  14. FFTF operating experience with sodium natural circulation: slides included

    SciTech Connect

    Burke, T.M.; Additon, S.L.; Beaver, T.R.; Midgett, J.C.

    1981-01-01

    The Fast Flux Test Facility (FFTF) has been designed for passive, back-up, safety grade decay heat removal utilizing natural circulation of the sodium coolant. This paper discusses the process by which operator preparation for this emergency operating mode has been assured, in paralled with the design verification during the FFTF startup and acceptance testing program. Over the course of the test program, additional insights were gained through the testing program, through on-going plant analyses and through general safety evaluations performed throughout the nuclear industry. These insights led to development of improved operator training material for control of decay heat removal during both forced and natural circulation as well as improvements in the related plant operating procedures.

  15. Optimization of magnetically accelerated, ultra-high velocity aluminum flyer plates for use in plate impact, shock wave experiments.

    SciTech Connect

    Cochrane, Kyle Robert; Knudson, Marcus D.; Slutz, Stephen A.; Lemke, Raymond William; Davis, J. P.; Harjes, Henry Charles III; Giunta, Anthony Andrew; Bliss, David Emery

    2005-05-01

    The intense magnetic field produced by the 20 MA Z accelerator is used as an impulsive pressure source to accelerate metal flyer plates to high velocity for the purpose of performing plate impact, shock wave experiments. This capability has been significantly enhanced by the recently developed pulse shaping capability of Z, which enables tailoring the rise time to peak current for a specific material and drive pressure to avoid shock formation within the flyer plate during acceleration. Consequently, full advantage can be taken of the available current to achieve the maximum possible magnetic drive pressure. In this way, peak magnetic drive pressures up to 490 GPa have been produced, which shocklessly accelerated 850 {micro}m aluminum (6061-T6) flyer plates to peak velocities of 34 km/s. We discuss magnetohydrodynamic (MHD) simulations that are used to optimize the magnetic pressure for a given flyer load and to determine the shape of the current rise time that precludes shock formation within the flyer during acceleration to peak velocity. In addition, we present results pertaining to plate impact, shock wave experiments in which the aluminum flyer plates were magnetically accelerated across a vacuum gap and impacted z-cut, {alpha}-quartz targets. Accurate measurements of resulting quartz shock velocities are presented and analyzed through high-fidelity MHD simulations enhanced using optimization techniques. Results show that a fraction of the flyer remains at solid density at impact, that the fraction of material at solid density decreases with increasing magnetic pressure, and that the observed abrupt decrease in the quartz shock velocity is well correlated with the melt transition in the aluminum flyer.

  16. The Pajarito Site operating procedures for the Los Alamos Critical Experiments Facility

    SciTech Connect

    Malenfant, R.E.

    1991-12-01

    Operating procedures consistent with DOE Order 5480.6, and the American National Standard Safety Guide for the Performance of Critical Experiments are defined for the Los Alamos Critical Experiments Facility (LACEF) of the Los Alamos National Laboratory. These operating procedures supersede and update those previously published in 1983 and apply to any criticality experiment performed at the facility. 11 refs.

  17. Ganges Valley Aerosol Experiment: Science and Operations Plan

    SciTech Connect

    Kotamarthi, VR

    2010-06-21

    The Ganges Valley region is one of the largest and most rapidly developing sections of the Indian subcontinent. The Ganges River, which provides the region with water needed for sustaining life, is fed primarily by snow and rainfall associated with Indian summer monsoons. Impacts of changes in precipitation patterns, temperature, and the flow of the snow-fed rivers can be immense. Recent satellite-based measurements have indicated that the upper Ganges Valley has some of the highest persistently observed aerosol optical depth values. The aerosol layer covers a vast region, extending across the Indo-Gangetic Plain to the Bay of Bengal during the winter and early spring of each year. The persistent winter fog in the region is already a cause of much concern, and several studies have been proposed to understand the economic, scientific, and societal dimensions of this problem. During the INDian Ocean EXperiment (INDOEX) field studies, aerosols from this region were shown to affect cloud formation and monsoon activity over the Indian Ocean. This is one of the few regions showing a trend toward increasing surface dimming and enhanced mid-tropospheric warming. Increasing air pollution over this region could modify the radiative balance through direct, indirect, and semi-indirect effects associated with aerosols. The consequences of aerosols and associated pollution for surface insolation over the Ganges Valley and monsoons, in particular, are not well understood. The proposed field study is designed for use of (1) the ARM Mobile Facility (AMF) to measure relevant radiative, cloud, convection, and aerosol optical characteristics over mainland India during an extended period of 9–12 months and (2) the G-1 aircraft and surface sites to measure relevant aerosol chemical, physical, and optical characteristics in the Ganges Valley during a period of 6–12 weeks. The aerosols in this region have complex sources, including burning of coal, biomass, and biofuels; automobile

  18. Special Operations of CERES for Radiation Experiment Tests (SOCRATES)

    NASA Astrophysics Data System (ADS)

    Szewczyk, Z. Peter

    The Clouds and Earth Radiant Energy System project flew a scanning radiometer (PFM) aboard the Tropical Rainfall Measuring Mission TRMM satellite, and two each aboard the Terra (FM1 FM2) and Aqua spacecraft (FM3 FM4). The primary objectives of the pairs of in-struments were for one to scan cross-track to map the geographical distribution of reflected solar radiation and Earth-emitted radiation and for the other to scan in azimuth as well as in elevation angle to provide data from which to develop models to describe the directionally-dependent dis-tribution of reflected solar radiance and Earth-emitted radiance. The Programmable Azimuth Plane Scan (PAPS) feature of the CERES instrument is a variant of the latter, and enables a scanner to target ground stations, or to match other satellite instruments viewing geometry to generate data sets for various scientific investigations. This paper presents special operations of CERES using the PAPS mode with the objective to collect data for comparison at the radiance level with other Earth Radiation Budget (ERB) instruments, and also shows numerical results of such comparisons. The following campaigns are covered in the paper: (i) In 1998, the CERES instrument (PFM) was rotated in azimuth so its scan plane coincided with the cross-track scan plane of the ScaRAB-2 instrument when the orbits of their spacecraft intersected. In this data set, both instruments viewed the same scenes from the same directions within a few minutes of each other, so the radiance measured by both instruments could be compared. (ii) In March of 2000, the scan plane of CERES Terra (FM1 and FM2) was rotated to coincide with the cross-track scan of the PFM aboard TRMM satellite. Data collected over up to 10 orbital crossings per day are used to compare radiance measurements of PFM and FM1 or FM2. (iii) In July of 2002, radiance measurements of scanners on Terra and Aqua satellites are compared. Since both satellites are in a polar orbit, the scan planes

  19. Entering "A NEW REALM" of KIBO Payload Operations - Continuous efforts for microgravity experiment environment and lessons learned from real time experiment operations in KIBO -

    NASA Astrophysics Data System (ADS)

    Sakagami, K.; Goto, M.; Matsumoto, S.; Ohkuma, H.

    2011-12-01

    On January 22nd, 2011(JST), KOUNOTORI2 (H-II Transfer Vehicle: HTV2) was successfully launched from Tanegashima Space Center toward the International Space Station (ISS) and two new JAXA payload racks, Kobairo rack and MSPR (Multi-purpose Small Payload Rack) were transferred to ISS/KIBO (Japanese Experiment Module: JEM). In addition to Saibo rack and Ryutai rack which are already in operation in KIBO, in total 4 Japanese experiment payload racks start operations in KIBO. Then KIBO payload operations embark on a new realm, full utilization phase. While the number and variety of microgravity experiments become increasing, simultaneous operation constraints should be considered to achieve multitask payload operations in ISS/KIBO and ever more complicated cooperative operations between crewmember and flight control team/science team are required. Especially for g-jitter improvement in ISS/KIBO, we have greatly advanced cooperative operations with crewmember in the recent increment based on the microgravity data analysis results. In this paper, newly operating Japanese experiment payloads characteristics and some methods to improve g-jitter environment are introduced from the front line of KIBO payload operations.

  20. Exposure Control for Operations and Maintenance at the Accelerator Production of Tritium

    SciTech Connect

    McGuire, D.H.

    1998-09-01

    The APT will be designed and operated to support continuous tritium production. Tritium is an essential ingredient in U.S. nuclear weapons. The APT will be designed and staffed to support continuous production of tritium by trained, qualified, and certified personnel.

  1. Neutrino factory and beta beam: accelerator options for future neutrino experiments

    SciTech Connect

    Zisman, Michael S.

    2012-06-03

    Two accelerator options for producing intense neutrino beams a Neutrino Factory based on stored muon beams and a Beta Beam facility based on stored beams of beta unstable ions are described. Technical challenges for each are described and current R&D efforts aimed at mitigating these challenges are indicated. Progress is being made in the design of both types of facility, each of which would extend the state-of-the-art in accelerator science.

  2. Experience from the construction and operation of the STAR PXL detector

    NASA Astrophysics Data System (ADS)

    Greiner, L.; Anderssen, E. C.; Contin, G.; Schambach, J.; Silber, J.; Stezelberger, T.; Sun, X.; Szelezniak, M.; Vu, C.; Wieman, H. H.; Woodmansee, S.

    2015-04-01

    A new silicon based vertex detector called the Heavy Flavor Tracker (HFT) was installed at the Soleniodal Tracker At RHIC (STAR) experiment for the Relativistic Heavy Ion Collider (RHIC) 2014 heavy ion run to improve the vertex resolution and extend the measurement capabilities of STAR in the heavy flavor domain. The HFT consists of four concentric cylinders around the STAR interaction point composed of three different silicon detector technologies based on strips, pads and for the first time in an accelerator experiment CMOS monolithic active pixels (MAPS) . The two innermost layers at a radius of 2.8 cm and 8 cm from the beam line are constructed with 400 high resolution MAPS sensors arranged in 10-sensor ladders mounted on 10 thin carbon fiber sectors giving a total silicon area of 0.16 m2. Each sensor consists of a pixel array of nearly 1 million pixels with a pitch of 20.7 μm with column-level discriminators, zero-suppression circuitry and output buffer memory integrated into one silicon die with a sensitive area of ~ 3.8 cm2. The pixel (PXL) detector has a low power dissipation of 170 mW/cm2, which allows air cooling. This results in a global material budget of 0.5% radiation length per layer for detector used in this run. A novel mechanical approach to detector insertion allows for the installation and integration of the pixel sub detector within a 12 hour period during an on-going STAR run. The detector specifications, experience from the construction and operation, lessons learned and initial measurements of the PXL performance in the 200 GeV Au-Au run will be presented.

  3. Three years of operational experience from Schauinsland CTBT monitoring station.

    PubMed

    Zähringer, M; Bieringer, J; Schlosser, C

    2008-04-01

    Data from three years of operation of a low-level aerosol sampler and analyzer (RASA) at Schauinsland monitoring station are reported. The system is part of the International Monitoring System (IMS) for verification of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). The fully automatic system is capable to measure aerosol borne gamma emitters with high sensitivity and routinely quantifies 7Be and 212Pb. The system had a high level of data availability of 90% within the reporting period. A daily screening process rendered 66 tentative identifications of verification relevant radionuclides since the system entered IMS operation in February 2004. Two of these were real events and associated to a plausible source. The remaining 64 cases can consistently be explained by detector background and statistical phenomena. Inter-comparison with data from a weekly sampler operated at the same station shows instabilities of the calibration during the test phase and a good agreement since certification of the system. PMID:18053622

  4. 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).

  5. Operating experience in preliminary hydrotreating of naphtha cuts

    SciTech Connect

    Sukharev, V.P.; Zhila, Yu.T.; Krylov, V.A.; Degterev, N.S.

    1987-05-01

    The authors consider the preliminary hydrotreating of naphtha cuts. A significant increase in the degree of sulfur removal was achieved as a result of using the catalysts GO-30-7 and GO-70. A flow plan is provided for hot separation in the L-35-11 unit. When the described measures were implemented, the preliminary hydrotreating sections operated more reliably, the energy consumption in the process was reduced, and the hydrotreated product met the requirements for feed to reformers operating on series KR catalysts.

  6. Supernova / Acceleration Probe: a Satellite Experiment to Study the Nature of the Dark Energy

    SciTech Connect

    Aldering, G.; Althouse, W.; Amanullah, R.; Annis, J.; Astier, P.; Baltay, C.; Barrelet, E.; Basa, S.; Bebek, C.; Bergstrom, L.; Bernstein, G.; Bester, M.; Bigelow, B.; Blandford, R.; Bohlin, R.; Bonissent, A.; Bower, C.; Brown, M.; Campbell, M.; Carithers, W.; Commins, E.; /LBL, Berkeley /SLAC /Stockholm U. /Fermilab /Paris U., VI-VII /Yale U. /Pennsylvania U. /UC, Berkeley /Michigan U. /Baltimore, Space Telescope Sci. /Marseille, CPPM /Indiana U. /American Astron. Society /Caltech /Case Western Reserve U. /Cambridge U. /Saclay /Lyon, IPN

    2005-08-15

    The Supernova/Acceleration Probe (SNAP) is a proposed space-based experiment designed to study the dark energy and alternative explanations of the acceleration of the Universe's expansion by performing a series of complementary systematics-controlled astrophysical measurements. We here describe a self-consistent reference mission design that can accomplish this goal with the two leading measurement approaches being the Type Ia supernova Hubble diagram and a wide-area weak gravitational lensing survey. This design has been optimized to first order and is now under study for further modification and optimization. A 2-m three-mirror anastigmat wide-field telescope feeds a focal plane consisting of a 0.7 square-degree imager tiled with equal areas of optical CCDs and near infrared sensors, and a high-efficiency low-resolution integral field spectrograph. The instrumentation suite provides simultaneous discovery and light-curve measurements of supernovae and then can target individual objects for detailed spectral characterization. The SNAP mission will discover thousands of Type Ia supernovae out to z = 3 and will obtain high-signal-to-noise calibrated light-curves and spectra for a subset of > 2000 supernovae at redshifts between z = 0.1 and 1.7 in a northern field and in a southern field. A wide-field survey covering one thousand square degrees in both northern and southern fields resolves {approx} 100 galaxies per square arcminute, or a total of more than 300 million galaxies. With the PSF stability afforded by a space observatory, SNAP will provide precise and accurate measurements of gravitational lensing. The high-quality data available in space, combined with the large sample of supernovae, will enable stringent control of systematic uncertainties. The resulting data set will be used to determine the energy density of dark energy and parameters that describe its dynamical behavior. The data also provide a direct test of theoretical models for the dark energy

  7. Supernova/Acceleration Probe: A Satellite Experiment to Study the Nature of the Dark Energy

    SciTech Connect

    Aldering, G.; Althouse, W.; Amanullah, R.; Annis, J.; Astier, P.; Baltay, C.; Barrelet, E.; Basa, E.; Bebek, C.; Bergstrom, L.; Bernstein, G.; Bester, M.; Bigelow, C.; Blandford, R.; Bohlin, R.; Bonissent, A.; Bower, C.; Brown, M.; Campbell, M.; Carithers, W.; Commins, E.; Craig, W.; Day, C.; DeJongh, F.; Deustua, S.; Diehl, T.; Dodelson, S.; Ealet, A.; Ellis, R.; Emmet, W.; Fouchez, D.; Frieman, J.; Fruchter, A.; Gerdes, D.; Gladney, L.; Goldhaber, G.; Goobar, A.; Groom, D.; Heetderks, H.; Hoff, M.; Holland, S.; Huffer, M.; Hui, L.; Huterer, D.; Jain, B.; Jelinsky, P.; Karcher, A.; Kent, S.; Kahn, S.; Kim, A.; Kolbe, W.; Krieger, B.; Kushner, G.; Kuznetsova, N.; Lafever, R.; Lamoureux, J.; Lampton, M.; Le Fevre, O.; Levi, M.; Limon, P.; Lin, H.; Linder, E.; Loken, S.; Lorenzon, W.; Malina, R.; Marriner, J.; Marshall, P.; Massey, R.; Mazure, A.; McKay, T.; McKee, S.; Miquel, R.; Morgan, N.; Mortsell, E.; Mostek, N.; Mufson, S.; Musser, J.; Nugent, P.; Oluseyi, H.; Pain, R.; Palaio, N.; Pankow, D.; Peoples, J.; Perlmutter, S.; Prieto, E.; Rabinowitz, D.; Refregier, A.; Rhodes, J.; Roe, N.; Rusin, D.; Scarpine, V.; Schubnell, M.; Sholl, M.; Samdja, G.; Smith, R.M.; Smoot, G.; Snyder, J.; Spadafora, A.; Stebbine, A.; Stoughton, C.; Szymkowiak, A.; Tarle, G.; Taylor, K.; Tilquin, A.; Tomasch, A.; Tucker, D.; Vincent, D.; von der Lippe, H.; Walder, J-P.; Wang, G.; Wester, W.

    2004-05-12

    The Supernova/Acceleration Probe (SNAP) is a proposed space-based experiment designed to study the dark energy and alternative explanations of the acceleration of the Universes expansion by performing a series of complementary systematics-controlled astrophysical measurements. We here describe a self-consistent reference mission design that can accomplish this goal with the two leading measurement approaches being the Type Ia supernova Hubble diagram and a wide-area weak gravitational lensing survey. This design has been optimized to first order and is now under study for further modification and optimization. A 2-m three-mirror anastigmat wide-field telescope feeds a focal plane consisting of a 0.7 square-degree imager tiled with equal areas of optical CCDs and near infrared sensors, and a high efficiency low-resolution integral field spectrograph. The instrumentation suite provides simultaneous discovery and light-curve measurements of supernovae and then can target individual objects for detailed spectral characterization. The SNAP mission will discover thousands of Type Ia supernovae out to z = 3 and will obtain high-signal-to-noise calibrated light-curves and spectra for a subset of > 2000 supernovae at redshifts between z = 0.1 and 1.7 in a northern field and in a southern field. A wide-field survey covering one thousand square degrees in both northern and southern fields resolves {approx} 100 galaxies per square arcminute, or a total of more than 300 million galaxies. With the PSF stability afforded by a space observatory, SNAP will provide precise and accurate measurements of gravitational lensing. The high-quality data available in space, combined with the large sample of supernovae, will enable stringent control of systematic uncertainties. The resulting data set will be used to determine the energy density of dark energy and parameters that describe its dynamical behavior. The data also provide a direct test of theoretical models for the dark energy

  8. Operational numerical weather prediction on a GPU-accelerated cluster supercomputer

    NASA Astrophysics Data System (ADS)

    Lapillonne, Xavier; Fuhrer, Oliver; Spörri, Pascal; Osuna, Carlos; Walser, André; Arteaga, Andrea; Gysi, Tobias; Rüdisühli, Stefan; Osterried, Katherine; Schulthess, Thomas

    2016-04-01

    The local area weather prediction model COSMO is used at MeteoSwiss to provide high resolution numerical weather predictions over the Alpine region. In order to benefit from the latest developments in computer technology the model was optimized and adapted to run on Graphical Processing Units (GPUs). Thanks to these model adaptations and the acquisition of a dedicated hybrid supercomputer a new set of operational applications have been introduced, COSMO-1 (1 km deterministic), COSMO-E (2 km ensemble) and KENDA (data assimilation) at MeteoSwiss. These new applications correspond to an increase of a factor 40x in terms of computational load as compared to the previous operational setup. We present an overview of the porting approach of the COSMO model to GPUs together with a detailed description of and performance results on the new hybrid Cray CS-Storm computer, Piz Kesch.

  9. Design of a hard X-ray beamline and end-station for pump and probe experiments at Pohang Accelerator Laboratory X-ray Free Electron Laser facility

    NASA Astrophysics Data System (ADS)

    Park, Jaeku; Eom, Intae; Kang, Tai-Hee; Rah, Seungyu; Nam, Ki Hyun; Park, Jaehyun; Kim, Sangsoo; Kwon, Soonam; Park, Sang Han; Kim, Kyung Sook; Hyun, Hyojung; Kim, Seung Nam; Lee, Eun Hee; Shin, Hocheol; Kim, Seonghan; Kim, Myong-jin; Shin, Hyun-Joon; Ahn, Docheon; Lim, Jun; Yu, Chung-Jong; Song, Changyong; Kim, Hyunjung; Noh, Do Young; Kang, Heung Sik; Kim, Bongsoo; Kim, Kwang-Woo; Ko, In Soo; Cho, Moo-Hyun; Kim, Sunam

    2016-02-01

    The Pohang Accelerator Laboratory X-ray Free Electron Laser project, a new worldwide-user facility to deliver ultrashort, laser-like x-ray photon pulses, will begin user operation in 2017 after one year of commissioning. Initially, it will provide two beamlines for hard and soft x-rays, respectively, and two experimental end-stations for the hard x-ray beamline will be constructed by the end of 2015. This article introduces one of the two hard x-ray end-stations, which is for hard x-ray pump-probe experiments, and primarily outlines the overall design of this end-station and its critical components. The content of this article will provide useful guidelines for the planning of experiments conducted at the new facility.

  10. One year's experience with an operating saturated solar pond

    SciTech Connect

    Ochs, T.L.; Stojanoff, C.G.; Day, D.L.

    1980-01-01

    While the saturated non-convecting solar pond concept is not new, the borax pond at the Desert Research Institute (DRI) is the first application of the concept to an operating solar pond. As with any new application there have been experimentally identified problem areas. Four of these problems are discussed: 1) departure from saturation, 2) contamination, 3) bottom crystalization, and 4) covers.

  11. Mountain Plains Learning Experience Guide: Lodging. Course: Housekeeping Operations.

    ERIC Educational Resources Information Center

    Fuhrman, D.; Egan, B.

    One of three individualized courses included in a lodging curriculum, this course covers basic housekeeping operations and procedures. The course is comprised of seven units: (1) Care of the Room, (2) Working with Staff, (3) Work Improvement Techniques, (4) Organizing, Planning, and Scheduling, (5) Housekeeping Material and Equipment, (6) Floor…

  12. Federated software defined network operations for LHC experiments

    NASA Astrophysics Data System (ADS)

    Kim, Dongkyun; Byeon, Okhwan; Cho, Kihyeon

    2013-09-01

    The most well-known high-energy physics collaboration, the Large Hadron Collider (LHC), which is based on e-Science, has been facing several challenges presented by its extraordinary instruments in terms of the generation, distribution, and analysis of large amounts of scientific data. Currently, data distribution issues are being resolved by adopting an advanced Internet technology called software defined networking (SDN). Stability of the SDN operations and management is demanded to keep the federated LHC data distribution networks reliable. Therefore, in this paper, an SDN operation architecture based on the distributed virtual network operations center (DvNOC) is proposed to enable LHC researchers to assume full control of their own global end-to-end data dissemination. This may achieve an enhanced data delivery performance based on data traffic offloading with delay variation. The evaluation results indicate that the overall end-to-end data delivery performance can be improved over multi-domain SDN environments based on the proposed federated SDN/DvNOC operation framework.

  13. OPERATING EXPERIENCE WITH EPA'S (ENVIRONMENTAL PROTECTION AGENCY'S) MOBILE INCINERATION SYSTEM

    EPA Science Inventory

    The paper describes the recent modifications made to the U.S. Environmental Protection Agency's (EPA) Mobile Incineration System. These modifications were aimed toward increasing the capacity of the system as well as its on-stream factor. The operation of the modified system was ...

  14. A Dust Characterization Experiment for Solar Cells Operating on Mars

    NASA Technical Reports Server (NTRS)

    Jenkins, Phillip; Landis, Geoffrey A.; Krasowski, Michael; Greer, Lawrence; Wilt, David; Baraona, Cosmo; Scheiman, David; Lekki, John

    2001-01-01

    During the Viking and Pathfinder missions to Mars, significant amounts of dust accumulated on the spacecrafts. In Pathfinder's case, the dust obscured the solar panels on the lander and the rover degrading their output current. The material adherence experiment aboard the Pathfinder rover quantified the rate of decrease in short circuit current at 0.28% per day. This rate is unacceptably high for long duration missions. In response, NASA has developed the Dust Accumulation and Removal Technology (DART) experiment. DART has three instruments for characterizing dust settling out of the atmosphere and tests two methods to keep dust from settling on solar cells.

  15. The Leisure Experience. Leisure Management Module. Operational Management Programme.

    ERIC Educational Resources Information Center

    Wright, Anthony; And Others

    This module on the leisure experience is intended to give the supervisor or manager an understanding of the nature and scope of the leisure market and key trends and developments. The material is presented in a self-instructional format in three sections. At the beginning of each section is a statement of the objectives that will be achieved as a…

  16. Generation and propagation of an electromagnetic pulse in the Trigger experiment and its possible role in electron acceleration

    NASA Technical Reports Server (NTRS)

    Kelley, M. C.; Kintner, P. M.; Kudeki, E.; Holmgren, G.; Bostrom, R.; Fahleson, U. V.

    1980-01-01

    Instruments onboard the Trigger payload detected a large-amplitude, low-frequency, electric field pulse which was observed with a time delay consistent only with an electromagnetic wave. A model for this perturbation is constructed, and the associated field-aligned current is calculated as a function of altitude. This experiment may simulate the acceleration mechanism which results in the formation of auroral arcs, and possibly even other events in cosmic plasmas.

  17. SNS Ring Operational Experience and Power Ramp Up Status

    SciTech Connect

    Plum, Michael A

    2009-01-01

    The SNS Ring has now been operating for about 3.5 years, and our march continues to increase the beam power to the full design value of 1.4 MW. The Ring is a loss-limited machine, and in general the radioactivation levels are good, but there are some unanticipated hot spots that we are working to improve. High intensity collective effects such as space-charge and beam instability have had minimal impact on beam operations to date. The cross plane coupling issue in the ring to target beam transport line has been solved. We will also discuss the status of equipment upgrades in the high-energy beam transport beam line, the injection-dump beam transport line, the ring, and the ring-to-target beam transport line.

  18. Analytical interfacial studies of double carbonate thermionic oxide cathodes over accelerated operational life

    NASA Astrophysics Data System (ADS)

    Barber, D. K.; Jenkins, S. N.; Whiting, M. J.; Baker, M. A.

    2005-09-01

    Interfacial interactions between the nickel cap and emissive oxide in double carbonate thermionic oxide cathodes have been studied as a function of operational lifetime by SEM, AES, EDX and TEM. The surface of the interface region has been studied by stripping away the oxide from the cap. In cross-section, the interface has been examined by (a) preparing 10° taper cross-sections and (b) cutting FIB sections. Cracks are observed to develop in the bulk Ni and become more pronounced as a function of operational lifetime. Cracks are found both at grain boundaries and close to the surface, parallel to the interface. It is proposed that the cracks develop from voids, formed as a result of the high diffusivity of Mg and Al in the Ni matrix. EDX shows the presence of Al, Mg, Ba, Sr and O within the cracks and it is proposed that MgO and (Ba, Sr)Al 2O 4 are two major reaction products. A thin (skin) layer containing Al, Ba, Sr and O forms at the Ni cap/emissive layer interface, attributed primarily to (Ba, Sr)Al 2O 4 formation.

  19. Cell inactivation, repair and mutation induction in bacteria after heavy ion exposure: results from experiments at accelerators and in space.

    PubMed

    Horneck, G; Schafer, M; Baltschukat, K; Weisbrod, U; Micke, U; Facius, R; Bucker, H

    1989-01-01

    To understand the mechanisms of accelerated heavy ions on biological matter, the responses of spores of B. subtilis to this structured high LET radiation was investigated applying two different approaches. 1) By the use of the Biostack concept, the inactivation probability as a function of radial distance to single particles' trajectory (i.e. impact parameter) was determined in space experiments as well as at accelerators using low fluences of heavy ions. It was found that spores can survive even a central hit and that the effective range of inactivation extends far beyond impact parameters where inactivation by delta-ray dose would be effective. Concerning the space experiment, the inactivation cross section exceeds those from comparable accelerator experiments by roughly a factor of 20. 2) From fluence effect curves, cross sections for inactivation and mutation induction, and the efficiency of repair processes were determined. They are influenced by the ions characteristics in a complex manner. According to dependence on LET, at least 3 LET ranges can be differentiated: A low LET range (app. < 200 keV/micrometers), where cross sections for inactivation and mutation induction follow a common curve for different ions and where repair processes are effective; an intermediate LET range of the so-called saturation cross section with negligible mutagenic and repair efficiency; and a high LET range (>1000 keV/micrometers) where the biological endpoints are majorly dependent on atomic mass and energy of the ion under consideration. PMID:11537282

  20. High Temperature Electrolysis Pressurized Experiment Design, Operation, and Results

    SciTech Connect

    J.E. O'Brien; X. Zhang; G.K. Housley; K. DeWall; L. Moore-McAteer

    2012-09-01

    A new facility has been developed at the Idaho National Laboratory for pressurized testing of solid oxide electrolysis stacks. Pressurized operation is envisioned for large-scale hydrogen production plants, yielding higher overall efficiencies when the hydrogen product is to be delivered at elevated pressure for tank storage or pipelines. Pressurized operation also supports higher mass flow rates of the process gases with smaller components. The test stand can accommodate planar cells with dimensions up to 8.5 cm x 8.5 cm and stacks of up to 25 cells. It is also suitable for testing other cell and stack geometries including tubular cells. The pressure boundary for these tests is a water-cooled spool-piece pressure vessel designed for operation up to 5 MPa. Pressurized operation of a ten-cell internally manifolded solid oxide electrolysis stack has been successfully demonstrated up 1.5 MPa. The stack is internally manifolded and operates in cross-flow with an inverted-U flow pattern. Feed-throughs for gas inlets/outlets, power, and instrumentation are all located in the bottom flange. The entire spool piece, with the exception of the bottom flange, can be lifted to allow access to the internal furnace and test fixture. Lifting is accomplished with a motorized threaded drive mechanism attached to a rigid structural frame. Stack mechanical compression is accomplished using springs that are located inside of the pressure boundary, but outside of the hot zone. Initial stack heatup and performance characterization occurs at ambient pressure followed by lowering and sealing of the pressure vessel and subsequent pressurization. Pressure equalization between the anode and cathode sides of the cells and the stack surroundings is ensured by combining all of the process gases downstream of the stack. Steady pressure is maintained by means of a backpressure regulator and a digital pressure controller. A full description of the pressurized test apparatus is provided in this