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Sample records for accelerated tests

  1. Accelerated cyclic corrosion tests

    Prošek T.

    2016-01-01

    Accelerated corrosion testing is indispensable for material selection, quality control and both initial and residual life time prediction for bare and painted metallic, polymeric, adhesive and other materials in atmospheric exposure conditions. The best known Neutral Salt Spray (NSS) test provides unrealistic conditions and poor correlation to exposures in atmosphere. Modern cyclic accelerated corrosion tests include intermittent salt spray, wet and dry phases and eventually other technical p...

  2. CESR Test Accelerator

    Rubin, David L

    2013-01-01

    The Cornell Electron Storage Ring (CESR) was reconfigured in 2008 as a test accelerator to investigate the physics of ultra-low emittance damping rings. During the approximately 40 days/year available for dedicated operation as a test accelerator, specialized instrumentation is used to measure growth and mitigation of the electron cloud, emittance growth due to electron cloud, intra-beam scattering, and ions, and single and multi-bunch instabilities generated by collective effects. The flexibility of the CESR guide field optics and the integration of accelerator modeling codes with the control system have made possible an extraordinary range of experiments. Findings at CesrTA with respect to electron cloud effects, emittance tuning techniques, and beam instrumentation for measuring electron cloud, beam sizes, and beam positions are the basis for much of the design of the ILC damping rings as documented in the ILC-Technical Design Report. The program has allowed the Cornell group to cultivate the kind of talen...

  3. Testing Gravity on Accelerators

    Kalaydzhyan, Tigran

    2016-01-01

    Weak equivalence principle (WEP) is one of the cornerstones of the modern theories of gravity, stating that the trajectory of a freely falling test body is independent of its internal structure and composition. Even though WEP is known to be valid for the normal matter with a high precision, it has never been experimentally confirmed for relativistic matter and antimatter. We make an attempt to constrain possible deviations from WEP utilizing the modern accelerator technologies. We analyze the (absence of) vacuum Cherenkov radiation, photon decay, anomalous synchrotron losses and the Compton spectra to put limits on the isotropic Lorentz violation and further convert them to the constraints on the difference between the gravitational and inertial masses of the relativistic electrons/positrons. Our main result is the 0.1% limit on the mentioned difference.

  4. The Brookhaven Accelerator Test Facility

    The Accelerator Test Facility (ATF), presently under construction at Brookhaven National laboratory, is described. It consists of a 50-MeV electron beam synchronizable to a high-peak power CO2 laser. The interaction of electrons with the laser field will be probed, with some emphasis on exploring laser-based acceleration techniques. 5 refs., 2 figs

  5. Advanced Superconducting Test Accelerator (ASTA)

    Federal Laboratory Consortium — The Advanced Superconducting Test Accelerator (ASTA) facility will be based on upgrades to the existing NML pulsed SRF facility. ASTA is envisioned to contain 3 to...

  6. Accelerated Testing Validation

    Mukundan, Rangachary; James, Greg; Davey, John; Langlois, David; Torraco, Dennis; Yoon, Wonseok; Weber, Adam Z; Borup, Rodney L.

    2011-07-01

    The DOE Fuel Cell technical team recommended ASTs were performed on 2 different MEAs (designated P5 and HD6) from Ballard Power Systems. These MEAs were also incorporated into stacks and operated in fuel cell bus modules that were either operated in the field (three P5 buses) in Hamburg, or on an Orange county transit authority drive cycle in the laboratory (HD6 bus module). Qualitative agreement was found in the degradation mechanisms and rates observed in the AST and in the field. The HD6 based MEAs exhibited lower voltage degradation rates (due to catalyst corrosion) and slower membrane degradation rates in the field as reflected by their superior performance in the high potential hold and open-circuit potential AST tests. The quantitative correlation of the degradation rates will have to take into account the various stressors in the field including temperature, relative humidity, start/stops and voltage cycles.

  7. Test accelerator for linear collider

    KEK has proposed to build Test Accelerator Facility (TAF) capable of producing a 2.5 GeV electron beam for the purpose of stimulating R ampersand D for linear collider in TeV region. The TAF consists of a 1.5 GeV S-band linear accelerator, 1.5 GeV damping ring and 1.0 GeV X-band linear accelerator. The TAF project will be carried forward in three phases. Through Phase-I and Phase-II, the S-band and X-band linacs will be constructed, and in Phase-III, the damping ring will be completed. The construction of TAF Phase-I has started, and the 0.2 GeV S-band injector linac has been almost completed. The Phase-I linac is composed of a 240 keV electron gun, subharmonic bunchers, prebunchers and traveling buncher followed by high-gradient accelerating structures. The SLAC 5045 klystrons are driven at 450 kV in order to obtain the rf-power of 100 MW in a 1 μs pulse duration. The rf-power from a pair of klystrons are combined into an accelerating structure. The accelerating gradient up to 100 MeV/m will be obtained in a 0.6 m long structure. 5 refs., 3 figs., 2 tabs

  8. The Brookhaven National Laboratory Accelerator Test Facility

    The Brookhaven National Laboratory Accelerator Test Facility comprises a 50 MeV traveling wave electron linear accelerator utilizing a high gradient, photo-excited, raidofrequency electron gun as an injector and an experimental area for study of new acceleration methods or advanced radiation sources using free electron lasers. Early operation of the linear accelerator system including calculated and measured beam parameters are presented together with the experimental program for accelerator physics and free electron laser studies

  9. Accelerated tests of coil coatings

    Rosales, B. M.

    2003-12-01

    Full Text Available Accelerated laboratory tests on 12 materials in study in the Subgroup 6 of the PATINA Network (CYTED, are discussed for different exposition periods in salt spray, SO2 and Prohesion chambers. International standards used to evaluate failures caused by the different aggressive agents of these laboratory tests are the same as those applied for outdoor expositions. The results exposed contribute to a better understanding of the mechanisms occurred in the diverse natural environments, being mentioned the main analogies and differences respect to factors affecting natural tests. They also allowed to evidence the advantages and limitations in the application of these tests during several days, as compared to the years required to attain similar failure magnitudes through outdoor tests.

    En este trabajo se discuten los ensayos de laboratorio acelerados, realizados sobre 12 materiales de estudio en el Subgrupo 6 de la Red PATINA (CYTED, a diferentes periodos de exposición en cámaras de niebla salina, SO2 y Prohesion. Se utilizaron las normas internacionales para evaluar los fallos causados por los diferentes agentes agresivos de estos ensayos de laboratorio, las cuales se aplican también para los ensayos de exposición a la intemperie. Los resultados expuestos contribuyen a una mejor comprensión de los mecanismos ocurridos en los diversos ambientes naturales, mencionándose las principales analogías y diferencias respecto de los factores que afectan los ensayos naturales. También permitieron evidenciar las ventajas y limitaciones en la aplicación de estos ensayos durante varios días, en comparación con los años requeridos para alcanzar magnitudes de fallos similares por medio de ensayos a intemperie.

  10. Accelerators for Fusion Materials Testing

    Knaster, Juan; Okumura, Yoshikazu

    Fusion materials research is a worldwide endeavor as old as the parallel one working toward the long term stable confinement of ignited plasma. In a fusion reactor, the preservation of the required minimum thermomechanical properties of the in-vessel components exposed to the severe irradiation and heat flux conditions is an indispensable factor for safe operation; it is also an essential goal for the economic viability of fusion. Energy from fusion power will be extracted from the 14 MeV neutron freed as a product of the deuterium-tritium fusion reactions; thus, this kinetic energy must be absorbed and efficiently evacuated and electricity eventually generated by the conventional methods of a thermal power plant. Worldwide technological efforts to understand the degradation of materials exposed to 14 MeV neutron fluxes >1018 m-2s-1, as expected in future fusion power plants, have been intense over the last four decades. Existing neutron sources can reach suitable dpa (“displacement-per-atom”, the figure of merit to assess materials degradation from being exposed to neutron irradiation), but the differences in the neutron spectrum of fission reactors and spallation sources do not allow one to unravel the physics and to anticipate the degradation of materials exposed to fusion neutrons. Fusion irradiation conditions can be achieved through Li (d, xn) nuclear reactions with suitable deuteron beam current and energy, and an adequate flowing lithium screen. This idea triggered in the late 1970s at Los Alamos National Laboratory (LANL) a campaign working toward the feasibility of continuous wave (CW) high current linacs framed by the Fusion Materials Irradiation Test (FMIT) project. These efforts continued with the Low Energy Demonstrating Accelerator (LEDA) (a validating prototype of the canceled Accelerator Production of Tritium (APT) project), which was proposed in 2002 to the fusion community as a 6.7MeV, 100mA CW beam injector for a Li (d, xn) source to bridge

  11. New Accelerating Modules RF Test at TTF

    Kostin, D

    2004-01-01

    Five new accelerating modules were installed into the TTF tunnel as a part of the VUV FEL Linac. They are tested prior to the linac operation. The RF test includes processing of the superconducting cavities, as well as maximum module performance tests. The test procedure and the achieved performance together with the test statistical analysis are presented.

  12. RHIC sextant test: Accelerator systems and performance

    One sextant of the RHIC Collider was commissioned in early 1997 with beam. We describe here the performance of the accelerator systems, instrumentation subsystems and application software. We also describe a ramping test without beam that took place after the commissioning with beam. Finally, we analyze the implications of accelerator systems performance and their impact on the planning for RHIC installation and commissioning

  13. Testing general relativity on accelerators

    Tigran Kalaydzhyan

    2015-11-01

    Full Text Available Within the general theory of relativity, the curvature of spacetime is related to the energy and momentum of the present matter and radiation. One of the more specific predictions of general relativity is the deflection of light and particle trajectories in the gravitational field of massive objects. Bending angles for electromagnetic waves and light in particular were measured with a high precision. However, the effect of gravity on relativistic massive particles was never studied experimentally. Here we propose and analyze experiments devoted to that purpose. We demonstrate a high sensitivity of the laser Compton scattering at high energy accelerators to the effects of gravity. The main observable – maximal energy of the scattered photons – would experience a significant shift in the ambient gravitational field even for otherwise negligible violation of the equivalence principle. We confirm predictions of general relativity for ultrarelativistic electrons of energy of tens of GeV at a current level of resolution and expect our work to be a starting point of further high-precision studies on current and future accelerators, such as PETRA, European XFEL and ILC.

  14. Testing general relativity on accelerators

    Kalaydzhyan, Tigran

    2015-11-01

    Within the general theory of relativity, the curvature of spacetime is related to the energy and momentum of the present matter and radiation. One of the more specific predictions of general relativity is the deflection of light and particle trajectories in the gravitational field of massive objects. Bending angles for electromagnetic waves and light in particular were measured with a high precision. However, the effect of gravity on relativistic massive particles was never studied experimentally. Here we propose and analyze experiments devoted to that purpose. We demonstrate a high sensitivity of the laser Compton scattering at high energy accelerators to the effects of gravity. The main observable - maximal energy of the scattered photons - would experience a significant shift in the ambient gravitational field even for otherwise negligible violation of the equivalence principle. We confirm predictions of general relativity for ultrarelativistic electrons of energy of tens of GeV at a current level of resolution and expect our work to be a starting point of further high-precision studies on current and future accelerators, such as PETRA, European XFEL and ILC.

  15. Solid oxide materials research accelerated electrochemical testing

    Windisch, C.; Arey, B.

    1995-08-01

    The objectives of this work were to develop methods for accelerated testing of cathode materials for solid oxide fuel cells under selected operating conditions. The methods would be used to evaluate the performance of LSM cathode material.

  16. Testing general relativity on accelerators

    Kalaydzhyan, Tigran

    2015-01-01

    Within the general theory of relativity, the curvature of spacetime is related to the energy and momentum of the present matter and radiation. One of the more specific predictions of general relativity is the deflection of light and particle trajectories in the gravitational field of massive objects. Bending angles for electromagnetic waves and light in particular were measured with a high precision. However, the effect of gravity on relativistic massive particles was never studied experimentally. Here we propose and analyse experiments devoted to that purpose. We demonstrate a high sensitivity of the laser Compton scattering at high energy accelerators to the effects of gravity. The main observable -- maximal energy of the scattered photons -- would experience a significant shift in the Earth's gravitational field even for otherwise negligible violation of the equivalence principle. We confirm predictions of general relativity for ultrarelativistic electrons of energy of tens of GeV at a current level of res...

  17. The electron test accelerator beam injector

    A beam chopper and buncher system has been designed to improve the capture efficiency and reduce the beam spill in the Electron Test Accelerator. The buncher increases the dc beam capture from 30 to 70%. 100% beam transmission through the accelerator structures is obtained with the chopper. This report describes results of experimental tests with the beam injector. Results from computer modeling and from measurements with prototypes that have led to the design of the beam chopper and buncher system are discussed

  18. A Comprehensive Review of Accelerated Life Test

    ZHANG Chun-hua; WANG Ya-shun; CHEN Xun; WEN Xi-sen

    2005-01-01

    Accelerated life test (ALT) is an important branch of reliability test and is a focus of research both for statisticians and reliability engineers. The paper outlines the four topics of study embodied in ALT: statistical analysis of constant-stress test, step-stress test and progressive stress test, and optimal design of ALT. It gives a general review of engineering applications of ALT, and points out some possible directions in ALT, gives some suggestions for further study.

  19. Next linear collider test accelerator injector upgrade

    Yeremian, A.D.; Miller, R.H. [Stanford Linear Accelerator Center, CA (United States)

    1995-12-31

    The Next Linear Collider Test Accelerator (NLCTA) is being constructed at SLAC to demonstrate multibunch beam loading compensation, suppression of higher order deflecting modes and measure transverse components of the accelerating fields in X-band accelerating structures. Currently a simple injector which provides the average current necessary for the beam loading compensations studies is under construction. An injector upgrade is planned to produce bunch trains similar to that of the NLC with microbunch intensity, separation and energy spread, identical to that of NLC. We discuss the design of the NLCTA injector upgrade.

  20. Accelerated degradation testing of a photovoltaic module

    Charki, Abdérafi; Laronde, Rémi; Bigaud, David

    2013-01-01

    There are a great many photovoltaic (PV) modules installed around the world. Despite this, not enough is known about the reliability of these modules. Their electrical power output decreases with time mainly as a result of the effects of corrosion, encapsulation discoloration, and solder bond failure. The failure of a PV module is defined as the point where the electrical power degradation reaches a given threshold value. Accelerated life tests (ALTs) are commonly used to assess the reliability of a PV module. However, ALTs provide limited data on the failure of a module and these tests are expensive to carry out. One possible solution is to conduct accelerated degradation tests. The Wiener process in conjunction with the accelerated failure time model makes it possible to carry out numerous simulations and thus to determine the failure time distribution based on the aforementioned threshold value. By this means, the failure time distribution and the lifetime (mean and uncertainty) can be evaluated.

  1. A Statistical Perspective on Highly Accelerated Testing.

    Thomas, Edward V.

    2015-02-01

    Highly accelerated life testing has been heavily promoted at Sandia (and elsewhere) as a means to rapidly identify product weaknesses caused by flaws in the product's design or manufacturing process. During product development, a small number of units are forced to fail at high stress. The failed units are then examined to determine the root causes of failure. The identification of the root causes of product failures exposed by highly accelerated life testing can instigate changes to the product's design and/or manufacturing process that result in a product with increased reliability. It is widely viewed that this qualitative use of highly accelerated life testing (often associated with the acronym HALT) can be useful. However, highly accelerated life testing has also been proposed as a quantitative means for "demonstrating" the reliability of a product where unreliability is associated with loss of margin via an identified and dominating failure mechanism. It is assumed that the dominant failure mechanism can be accelerated by changing the level of a stress factor that is assumed to be related to the dominant failure mode. In extreme cases, a minimal number of units (often from a pre-production lot) are subjected to a single highly accelerated stress relative to normal use. If no (or, sufficiently few) units fail at this high stress level, some might claim that a certain level of reliability has been demonstrated (relative to normal use conditions). Underlying this claim are assumptions regarding the level of knowledge associated with the relationship between the stress level and the probability of failure. The primary purpose of this document is to discuss (from a statistical perspective) the efficacy of using accelerated life testing protocols (and, in particular, "highly accelerated" protocols) to make quantitative inferences concerning the performance of a product (e.g., reliability) when in fact there is lack-of-knowledge and uncertainty concerning

  2. RHIC Sextant Test - Accelerator Systems and Performance

    Pilat, F.; Ahrens, L.; Brown, K.; Connolly, R.; dell, G. F.; Fischer, W.; Kewisch, J.; Mackay, W.; Mane, V.; Peggs, S.; Satogata, T.; Tepikian, S.; Thompson, P.; Trbojevic, D.; Tsoupas, N.; Wei, J.

    1997-05-01

    One sextant of the RHIC collider and the full AtR (AGS to RHIC) transfer line have been commissioned in early 1997 with beam. We describe here the design and performance of the accelerator systems during the test, such as the magnet and power supply systems, instrumentation subsystems and application software. After reviewing the main milestones of the commissioning we describe a ramping test without beam that took place after the commissioning with beam. Finally, we analyze the implications of accelerator systems preformance and their impact on the plannig for RHIC installation and commissioning.

  3. Test Stand for Linear Induction Accelerator Optimization

    Lawrence Livermore National Laboratory has designed and constructed a test stand to improve the voltage regulation in our Flash X-Ray (FXR) accelerator cell. The goal is to create a more mono-energetic electron beam that will create an x-ray source with a smaller spot size. Studying the interaction of the beam and pulse-power system with the accelerator cell will improve the design of high-current accelerators at Livermore and elsewhere. On the test stand, a standard FXR cell is driven by a flexible pulse-power system and the beam current is simulated with a switched center conductor. The test stand is fully instrumented with high-speed digitizers to document the effect of impedance mismatches when the cell is operated under various full-voltage conditions. A time-domain reflectometry technique was also developed to characterize the beam and cell interactions by measuring the impedance of the accelerator and pulse-power component. Computer models are being developed in parallel with the testing program to validate the measurements and evaluate different design changes. Both 3D transient electromagnetic and circuit models are being used

  4. The BNL Accelerator Test Facility control system

    Described is the VAX/CAMAC-based control system for Brookhaven National Laboratory's Accelerator Test Facility, a laser/linac research complex. Details of hardware and software configurations are presented along with experiences of using Vsystem, a commercial control system package

  5. Test Particles with Acceleration-Dependent Lagrangian

    Toller, M

    2006-01-01

    We consider a classical test particle subject to electromagnetic and gravitational fields, described by a Lagrangian depending on the acceleration and on a fundamental length. We associate to the particle a moving local reference frame and we study its trajectory in the principal fibre bundle of all the Lorentz frames. We discuss in this framework the general form of the Lagrange equations and the connection between symmetries and conservation laws (Noether theorem). We apply these results to a model, already discussed by other authors, which implies an upper bound to the proper acceleration and to another new model in which a similar quantity, called ``pseudo-acceleration'', is bounded. With some simple choices of the fields, we illustrate some other interesting properties of the models and we show that unwanted features may appear, as instable run-away solutions and unphysical values of the energy-momentum or of the velocity.

  6. Manufacturing and Testing of Accelerator Superconducting Magnets

    Rossi, L

    2014-01-01

    Manufacturing of superconducting magnet for accelerators is a quite complex process that is not yet fully industrialized. In this paper, after a short history of the evolution of the magnet design and construction, we review the main characteristics of the accelerator magnets having an impact on the construction technology. We put in evidence how the design and component quality impact on construction and why the final product calls for a total-quality approach. LHC experience is widely discussed and main lessons are spelled out. Then the new Nb3Sn technology, under development for the next generation magnet construction, is outlined. Finally, we briefly review the testing procedure of accelerator superconducting magnets, underlining the close connection with the design validation and with the manufacturing process.

  7. Tests of compressed geometry acceleration tubes in the Oak Ridge 25URC tandem accelerator

    In an effort to further improve voltage performance of the Oak Ridge 25URC accelerator, the original acceleration tubes will be replaced with NEC compressed geometry acceleration tubes. In this paper, we report on tests in the 25URC accelerator of two prototype compressed geometry acceleration tube designs. One of the designs utilizes a novel aperture which provides enhanced electron and ion trapping

  8. Test Particles with Acceleration-Dependent Lagrangian

    Toller, M.

    2005-01-01

    We consider a classical test particle subject to electromagnetic and gravitational fields, described by a Lagrangian depending on the acceleration and on a fundamental length. We associate to the particle a moving local reference frame and we study its trajectory in the principal fibre bundle of all the Lorentz frames. We discuss in this framework the general form of the Lagrange equations and the connection between symmetries and conservation laws (Noether theorem). We apply these results to...

  9. BNL ACCELERATOR TEST FACILITY CONTROL SYSTEM UPGRADE.

    MALONE,R.; BEN-ZVI,I.; WANG,X.; YAKIMENKO,V.

    2001-06-18

    Brookhaven National Laboratory's Accelerator Test Facility (ATF) has embarked on a complete upgrade of its decade old computer system. The planned improvements affect every major component: processors (Intel Pentium replaces VAXes), operating system (Linux/Real-Time Linux supplants OpenVMS), and data acquisition equipment (fast Ethernet equipment replaces CAMAC serial highway.) This paper summarizes the strategies and progress of the upgrade along with plans for future expansion.

  10. Vacuum system for Advanced Test Accelerator

    Denhoy, B.S.

    1981-09-03

    The Advanced Test Accelerator (ATA) is a pulsed linear electron beam accelerator designed to study charged particle beam propagation. ATA is designed to produce a 10,000 amp 50 MeV, 70 ns electron beam. The electron beam acceleration is accomplished in ferrite loaded cells. Each cell is capable of maintaining a 70 ns 250 kV voltage pulse across a 1 inch gap. The electron beam is contained in a 5 inch diameter, 300 foot long tube. Cryopumps turbomolecular pumps, and mechanical pumps are used to maintain a base pressure of 2 x 10/sup -6/ torr in the beam tube. The accelerator will be installed in an underground tunnel. Due to the radiation environment in the tunnel, the controlling and monitoring of the vacuum equipment, pressures and temperatures will be done from the control room through a computer interface. This paper describes the vacuum system design, the type of vacuum pumps specified, the reasons behind the selection of the pumps and the techniques used for computer interfacing.

  11. Vacuum system for Advanced Test Accelerator

    The Advanced Test Accelerator (ATA) is a pulsed linear electron beam accelerator designed to study charged particle beam propagation. ATA is designed to produce a 10,000 amp 50 MeV, 70 ns electron beam. The electron beam acceleration is accomplished in ferrite loaded cells. Each cell is capable of maintaining a 70 ns 250 kV voltage pulse across a 1 inch gap. The electron beam is contained in a 5 inch diameter, 300 foot long tube. Cryopumps turbomolecular pumps, and mechanical pumps are used to maintain a base pressure of 2 x 10-6 torr in the beam tube. The accelerator will be installed in an underground tunnel. Due to the radiation environment in the tunnel, the controlling and monitoring of the vacuum equipment, pressures and temperatures will be done from the control room through a computer interface. This paper describes the vacuum system design, the type of vacuum pumps specified, the reasons behind the selection of the pumps and the techniques used for computer interfacing

  12. Accelerated Leach Test(s) Program: Annual report

    A computerized data base of LLW leaching data has been developed. Long-term tests on portland cement, bitumen and vinyl ester-styrene (VES) polymer waste forms containing simulated wastes are underway which are designed to identify and evaluate factors that accelerate leaching without changing the mechanisms

  13. Accelerated Leach Test(s) Program: Annual report

    Dougherty, D.R.; Pietrzak, R.F.; Fuhrmann, M.; Colombo, P.

    1986-09-01

    A computerized data base of LLW leaching data has been developed. Long-term tests on portland cement, bitumen and vinyl ester-styrene (VES) polymer waste forms containing simulated wastes are underway which are designed to identify and evaluate factors that accelerate leaching without changing the mechanisms.

  14. Stripline kicker for integrable optics test accelerator

    Antipov, Sergey A.; Didenko, Alexander; Lebedev, Valeri; Valishev, Alexander

    2016-01-01

    We present a design of a stripline kicker for Integrable Optics Test Accelerator (IOTA). For its experimental program IOTA needs two full-aperture kickers, capable to create an arbitrary controllable kick in 2D. For that reason their strengths are variable in a wide range of amplitudes up to 16 mrad, and the pulse length 100 ns is less than a revolution period for electrons. In addition, the kicker should have a physical aperture of 40 mm for a proposed operation with proton beam, and an oute...

  15. Laboratory Test of Newton's Second Law for Small Accelerations

    We have tested the proportionality of force and acceleration in Newton's second law, F=ma, in the limit of small forces and accelerations. Our tests reach well below the acceleration scales relevant to understanding several current astrophysical puzzles such as the flatness of galactic rotation curves, the Pioneer anomaly, and the Hubble acceleration. We find good agreement with Newton's second law at accelerations as small as 5x10-14 m/s2

  16. Induction accelerator test module for HIF

    An induction linac test module suitable for investigating the drive requirements and the longitudinal coupling impedance of a high-power ion induction linac has been constructed by the Heavy Ion Fusion (HIF) group at LBL. The induction linac heavy ion driver for inertial confinement fusion (ICF) as presently envisioned uses multiple parallel beams which are transported in separate focusing channels but accelerated together in the induction modules. The resulting induction modules consequently have large beam apertures-1--2 meters in diameter- and correspondingly large outside diameters. The module geometry is related to a low-frequency ''gap capacity'' and high-frequency structural resonances, which are affected by the magnetic core loading and the module pulser impedance. A description of the test module and preliminary results are presented. 3 figs

  17. Flame Acceleration Tests with Hydrogen Combustions

    According to the domestic and foreign regulations, a detonation or DDT (deflagration to detonation transition) by a hydrogen combustion should be prohibited to occur in a containment of a nuclear power plant. A hydrogen control in the IRWST(Incontainment Refueling Water Storage Tank) under a severe accident still remains a debatable issue to be solved in APR1400. The characteristics of the hydrogen flame in the IRWST expected during the station black-out (SBO) and total loss of feed water (LOFW) accidents have been evaluated based on a sigma-lambda criteria from the simulation results by the numerical codes such as GASFLOW. And it was found that hydrogen mixture was non-flammable most of the accident time when the non-condensed steam was released into the free volume of the IRWST, but there existed a small period of time with a high possibility of a flame acceleration during the SBO accident because most of the steam discharged from sparger was well condensed. Therefore, detail analysis and experiment of the hydrogen flame should be required to fix a DDT possibility by the hydrogen combustion in the IRWST of the APR1400. Most experiments on the hydrogen combustion have been limited only to straight pipes or channels. However, the hydrogen flame acceleration phenomena in the IRWST with a closed annular path may be different from those in the straight path in respect to a centrifugal force and degree of freedom in flame propagation etc. So, an experiment of hydrogen combustion in a closed annular chamber is needed to find out the geometrical effect on the flame propagation and to validate the numerical results. KAERI has been performing the experiments of the hydrogen combustion in the IRWST. As the fist stage, flame acceleration tests with the hydrogen combustions are studied preliminarily for a circular straight pipe to confirm the characteristics hydrogen flame propagation, and to evaluate flame detection systems

  18. Accelerated Strength Testing of Thermoplastic Composites

    Reeder, J. R.; Allen, D. H.; Bradley, W. L.

    1998-01-01

    Constant ramp strength tests on unidirectional thermoplastic composite specimens oriented in the 90 deg. direction were conducted at constant temperatures ranging from 149 C to 232 C. Ramp rates spanning 5 orders of magnitude were tested so that failures occurred in the range from 0.5 sec. to 24 hrs. (0.5 to 100,000 MPa/sec). Below 204 C, time-temperature superposition held allowing strength at longer times to be estimated from strength tests at shorter times but higher temperatures. The data indicated that a 50% drop in strength might be expected for this material when the test time is increased by 9 orders of magnitude. The shift factors derived from compliance data applied well to the strength results. To explain the link between compliance and strength, a viscoelastic fracture model was investigated. The model, which used compliance as input, was found to fit the strength data only if the critical fracture energy was allowed to vary with temperature reduced stress rate. This variation in the critical parameter severely limits its use in developing a robust time-dependent strength model. The significance of this research is therefore seen as providing both the indication that a more versatile acceleration method for strength can be developed and the evidence that such a method is needed.

  19. Hurricane Isabel gives accelerators a severe test

    Hurricane Isabel was at category five--the most violent on the Saffir-Simpson scale of hurricane strength--when it began threatening the central Atlantic seaboard of the US. Over the course of several days, precautions against the extreme weather conditions were taken across the Jefferson Lab site in south-east Virginia. On 18 September 2003, when Isabel struck North Carolina's Outer Banks and moved northward, directly across the region around the laboratory, the storm was still quite destructive, albeit considerably reduced in strength. The flood surge and trees felled by wind substantially damaged or even devastated buildings and homes, including many belonging to Jefferson Lab staff members. For the laboratory itself, Isabel delivered an unplanned and severe challenge in another form: a power outage that lasted nearly three-and-a-half days, and which severely tested the robustness of Jefferson Lab's two superconducting machines, the Continuous Electron Beam Accelerator Facility (CEBAF) and the superconducting radiofrequency ''driver'' accelerator of the laboratory's free-electron laser. Robustness matters greatly for science at a time when microwave superconducting linear accelerators (linacs) are not only being considered, but in some cases already being built for projects such as neutron sources, rare-isotope accelerators, innovative light sources and TeV-scale electron-positron linear colliders. Hurricane Isabel interrupted a several-week-long maintenance shutdown of CEBAF, which serves nuclear and particle physics and represents the world's pioneering large-scale implementation of superconducting radiofrequency (SRF) technology. The racetrack-shaped machine is actually a pair of 500-600 MeV SRF linacs interconnected by recirculation arc beamlines. CEBAF delivers simultaneous beams at up to 6 GeV to three experimental halls. An imminent upgrade will double the energy to 12 GeV and add an extra hall for ''quark confinement'' studies. On a smaller scale

  20. Planck scale gravity test with accelerators

    Gharibyan, Vahagn

    2012-07-15

    Quantum or torsion gravity models predict unusual properties of space-time at very short distances. In particular, near the Planck length, around 10{sup -35} m, empty space may behave as a crystal, singly or doubly refractive. However, this hypothesis remains uncheckable for any direct measurement since the smallest distance accessible in experiment is about 10{sup -19} m at the LHC. Here I propose a laboratory test to measure the space refractivity and birefringence induced by gravity. A sensitivity from 10{sup -31} m down to the Planck length could be reached at existent GeV and future TeV energy lepton accelerators using laser Compton scattering. There are already experimental hints for gravity signature at distances approaching the Planck length by 5-7 orders of magnitude, derived from SLC and HERA data.

  1. Stripline kicker for integrable optics test accelerator

    Antipov, Sergey A.; Didenko, Alexander; Lebedev, Valeri; Valishev, Alexander

    2016-06-30

    We present a design of a stripline kicker for Integrable Optics Test Accelerator (IOTA). For its experimental program IOTA needs two full-aperture kickers, capable to create an arbitrary controllable kick in 2D. For that reason their strengths are variable in a wide range of amplitudes up to 16 mrad, and the pulse length 100 ns is less than a revolution period for electrons. In addition, the kicker should have a physical aperture of 40 mm for a proposed operation with proton beam, and an outer size of 70 mm to fit inside existing quadrupole magnets to save space in the ring. Computer simulations using CST Microwave Studio show high field uniformity and wave impedance close to 50 {\\Omega}.

  2. Planck scale gravity test with accelerators

    Quantum or torsion gravity models predict unusual properties of space-time at very short distances. In particular, near the Planck length, around 10-35 m, empty space may behave as a crystal, singly or doubly refractive. However, this hypothesis remains uncheckable for any direct measurement since the smallest distance accessible in experiment is about 10-19 m at the LHC. Here I propose a laboratory test to measure the space refractivity and birefringence induced by gravity. A sensitivity from 10-31 m down to the Planck length could be reached at existent GeV and future TeV energy lepton accelerators using laser Compton scattering. There are already experimental hints for gravity signature at distances approaching the Planck length by 5-7 orders of magnitude, derived from SLC and HERA data.

  3. Stripline kicker for integrable optics test accelerator

    Antipov, Sergey A; Lebedev, Valeri; Valishev, Alexander

    2016-01-01

    We present a design of a stripline kicker for Integrable Optics Test Accelerator (IOTA). For its experimental program IOTA needs two full-aperture kickers, capable to create an arbitrary controllable kick in 2D. For that reason their strengths are variable in a wide range of amplitudes up to 16 mrad, and the pulse length 100 ns is less than a revolution period for electrons. In addition, the kicker should have a physical aperture of 40 mm for a proposed operation with proton beam, and an outer size of 70 mm to fit inside existing quadrupole magnets to save space in the ring. Computer simulations using CST Microwave Studio show high field uniformity and wave impedance close to 50 {\\Omega}.

  4. Accelerated testing statistical models, test plans, and data analysis

    Nelson, Wayne B

    2009-01-01

    The Wiley-Interscience Paperback Series consists of selected books that have been made more accessible to consumers in an effort to increase global appeal and general circulation. With these new unabridged softcover volumes, Wiley hopes to extend the lives of these works by making them available to future generations of statisticians, mathematicians, and scientists. "". . . a goldmine of knowledge on accelerated life testing principles and practices . . . one of the very few capable of advancing the science of reliability. It definitely belongs in every bookshelf on engineering.""-Dev G.

  5. Beam Physics of Integrable Optics Test Accelerator at Fermilab

    Nagaitsev, S.; Valishev, A.; Danilov, V. V.; Shatilov, D. N.

    2013-01-01

    Fermilab's Integrable Optics Test Accelerator is an electron storage ring designed for testing advanced accelerator physics concepts, including implementation of nonlinear integrable beam optics and experiments on optical stochastic cooling. The machine is currently under construction at the Advanced Superconducting Test Accelerator facility. In this report we present the goals and the current status of the project, and describe the details of machine design. In particular, we concentrate on ...

  6. Operation of the Brookhaven National Laboratory Accelerator Test Facility

    Early operation of the 50 MeV high brightness electron linac of the Accelerator Test Facility is described along with experimental data. This facility is designed to study new linear acceleration techniques and new radiation sources based on linacs in combination with free electron lasers. The accelerator utilizes a photo-excited, metal cathode, radio frequency electron gun followed by two travelling wave accelerating sections and an Experimental Hall for the study program

  7. Operation of the Brookhaven national laboratory accelerator test facility

    Early operation of the 50 MeV high brightness electron linac of the Accelerator Test Facility is described along with experimental data. This facility is designed to study new linear acceleration techniques and new radiation sources based on linacs in combination with free electron lasers. The accelerator utilizes a photo-excited, metal cathode, radio frequency electron gun followed by two travelling wave accelerating sections and an Experimental Hall for the study program. (Author) 5 refs., 4 figs., tab

  8. Virtual accelerator concept, implementation and preliminary test

    A virtual accelerator is the coupling of a simulation code with the control system of a real machine. 3 operating modes are considered. First, the monitoring mode in which any action on the control system has an impact on both real and virtual machines. This mode allows a direct comparison between simulation results and the real behaviour of the accelerator. Secondly, the flight simulation mode, this mode allows the accelerator operators to simulate the effect of any change in the parameters of the control system before transferring them to the real machine. The main advantage of this mode is to allow the assessment of operating procedures before implementing them on the real machine. The third mode is the automatic steering mode in which the simulation code assumes the reins of the control system of the real machine. This mode allows the making of complex and time-consuming adjustment procedures in an automatic way. TraceWin is a simulation code dedicated to the behaviour of charged-particle beams in a linear accelerator. TraceWin is consistent with the EPICS technology on which the control system of most accelerators is based. A virtual accelerator composed of the SILHI injector combined to the TraceWin code via the EPICS environment has showed its efficiency in the automatic steering mode. (A.C.)

  9. Accelerated lifetime testing of energy storage capacitors used in particle accelerators power converters

    AUTHOR|(SzGeCERN)679542; Genton, Charles-Mathieu

    2015-01-01

    Energy storage capacitors are used in large quantities in high power converters for particle accelerators. In this application capacitors see neither a DC nor an AC voltage but a combination of the two. The paper presents a new power converter explicitly designed to perform accelerated testing on these capacitors and the results of the tests.

  10. AREAL test facility for advanced accelerator and radiation source concepts

    Tsakanov, V. M.; Amatuni, G. A.; Amirkhanyan, Z. G.; Aslyan, L. V.; Avagyan, V. Sh.; Danielyan, V. A.; Davtyan, H. D.; Dekhtiarov, V. S.; Gevorgyan, K. L.; Ghazaryan, N. G.; Grigoryan, B. A.; Grigoryan, A. H.; Hakobyan, L. S.; Haroutiunian, S. G.; Ivanyan, M. I.; Khachatryan, V. G.; Laziev, E. M.; Manukyan, P. S.; Margaryan, I. N.; Markosyan, T. M.; Martirosyan, N. V.; Mehrabyan, Sh. A.; Mkrtchyan, T. H.; Muradyan, L. Kh.; Nikogosyan, G. H.; Petrosyan, V. H.; Sahakyan, V. V.; Sargsyan, A. A.; Simonyan, A. S.; Toneyan, H. A.; Tsakanian, A. V.; Vardanyan, T. L.; Vardanyan, A. S.; Yeremyan, A. S.; Zakaryan, S. V.; Zanyan, G. S.

    2016-09-01

    Advanced Research Electron Accelerator Laboratory (AREAL) is a 50 MeV electron linear accelerator project with a laser driven RF gun being constructed at the CANDLE Synchrotron Research Institute. In addition to applications in life and materials sciences, the project aims as a test facility for advanced accelerator and radiation source concepts. In this paper, the AREAL RF photoinjector performance, the facility design considerations and its highlights in the fields of free electron laser, the study of new high frequency accelerating structures, the beam microbunching and wakefield acceleration concepts are presented.

  11. Terrestrial Photovoltaic Module Accelerated Test-To-Failure Protocol

    Osterwald, C. R.

    2008-03-01

    This technical report documents a test-to-failure protocol that may be used to obtain quantitative information about the reliability of photovoltaic modules using accelerated testing in environmental temperature-humidity chambers.

  12. Accelerators for Society - TIARA 2012 Test Infrastructure and Accelerator Research Area (in Polish)

    Romaniuk, R S

    2013-01-01

    TIARA (Test Infrastructure and Accelerator Research Area - Preparatory Phae) is an European Collaboration of Accelerator Technology, which by running research projects, technical, networks and infrastructural has a duty to integrate the research and technical communities and infrastructures in the global scale of Europe. The Collaboration gathers all research centers with large accelerator infrastructures. Other ones, like universities, are affiliated as associate members. TIARA-PP (preparato...

  13. Accelerated Test Method for Corrosion Protective Coatings Project

    Falker, John; Zeitlin, Nancy; Calle, Luz

    2015-01-01

    This project seeks to develop a new accelerated corrosion test method that predicts the long-term corrosion protection performance of spaceport structure coatings as accurately and reliably as current long-term atmospheric exposure tests. This new accelerated test method will shorten the time needed to evaluate the corrosion protection performance of coatings for NASA's critical ground support structures. Lifetime prediction for spaceport structure coatings has a 5-year qualification cycle using atmospheric exposure. Current accelerated corrosion tests often provide false positives and negatives for coating performance, do not correlate to atmospheric corrosion exposure results, and do not correlate with atmospheric exposure timescales for lifetime prediction.

  14. The electron test accelerator safety in design and operation

    The Electron Test Accelerator is being designed as an experiment in accelerator physics and technology. With an electron beam power of up to 200 kW the operation of the accelerator presents a severe radiation hazard as well as rf and electrical hazards. The design of the safety system provides fail-safe protection while permitting flexibility in the mode of operation and minimizing administrative controls. (auth)

  15. Beam acceleration test of the HIMAC injector

    A heavy-ion synchrotron dedicated to medical use is under construction at National Institute of Radiological Sciences. The injector system, comprising a PIG source, an ECR source, an RFQ linac, and an Alvarez linac of 100MHz, accelerates heavy ions with a charge-to-mass ratio as small as 1/7, up to 6 MeV/u. First operation of the injector system has shown satisfactory performance. (author)

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

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

    2011-01-01

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

  17. Accelerators for Society - TIARA 2012 Test Infrastructure and Accelerator Research Area (in Polish)

    Romaniuk, R S

    2013-01-01

    TIARA (Test Infrastructure and Accelerator Research Area - Preparatory Phae) is an European Collaboration of Accelerator Technology, which by running research projects, technical, networks and infrastructural has a duty to integrate the research and technical communities and infrastructures in the global scale of Europe. The Collaboration gathers all research centers with large accelerator infrastructures. Other ones, like universities, are affiliated as associate members. TIARA-PP (preparatory phase) is an European infrastructural project run by this Consortium and realized inside EU-FP7. The paper presents a general overview of TIARA activities, with an introduction containing a portrait of contemporary accelerator technology and a digest of its applications in modern society.

  18. An Accelerated Stress Test Method for Electrostatically Driven MEMS Devices

    Ruan, Jinyu Jason; Monnereau, Nicolas; Trémouilles, David; Mauran, Nicolas; Coccetti, Fabio; Nolhier, Nicolas; Plana, Robert

    2012-01-01

    This paper addresses an innovative solution to develop a circuit to perform accelerated stress tests of capacitive microelectromechanical-system (MEMS) switches and shows the use of instruments and equipment to monitor physical aging phenomena. A dedicated test circuit was designed and fabricated in order to meet the need for accelerated techniques for those structures. It integrated an in-house miniaturized circuit connected to additional test equipment (e.g., oscilloscopes and capacitance m...

  19. Preliminary power test on C-band accelerator

    A C-band 2 MeV standing wave accelerator is under development for engineering research on accelerator miniaturization. At present, significant progress has been achieved. The accelerating tube has been fully sealed, and the hot test platform for the accelerator has been built. At the repetition rate of 50 Hz, preliminary power test has been performed. It used the ionization chamber dose monitor to test the dose rate of X-rays at 1 m before the target, and the steel absorption method to test the energy of the electron beam. The preliminary test results show that, the beam energy is about 2.5 MeV, and the dose rate can be over 330 mGy/(min · m). (authors)

  20. Scientists confirm delay in testing new CERN particle accelerator

    2007-01-01

    "Scientists seeking to uncover the secrets of the universe will have to wait a little longer after the CERN laboratory inswitzerland on Monday confirmed a delay in tests of a massive new particle accelerator." (1 page)

  1. Development of a new accelerated salt crystallization test

    Wijffels, T.J.; Lubelli, B.A.

    2006-01-01

    TNO Built Environment and Geosciences has developed, in cooperation with other institutes in the European project Compass1, a new accelerated salt crystallization test. In this paper the design process leading to the definition of this test is described. Preliminary tests studying the influence of t

  2. Testing of high-vacuum pumps for charged particle accelerators

    To study a possibility of employing different types of pumps in charged-particle accelerators the following pumps have been tested: electric-arc, turbomolecular and cryogenic. The research has been carried out on a test bench which made it possible to determine the pumping-out rate for different gases (constant-volume methods), measure their limiting pressure and study the spectra of different gases by using mass spectrometers. It was possible also to warm up the pumps and pumped-out volumes. From these tests it was concluded that: (1) the electric-arc pump does not meet the accelerator pumping-out requirements; (2) the turbomolecular pump with a nitrogen-sorption trap can be recommended for pumping-out accelerators but requires modification of the supply unit; (3) the cryogenic pump can be recommended for pumpimg-out of accelerators but requires modification of the automatic system for replenishment of the cryogenic fluid

  3. Recent progress of the advanced test accelerator

    Prono, D.S.

    1985-05-13

    Attempts to further improve the beam brightness from field emission cathodes are currently centered on the issue of how beam optics and phase mixing within the injector transport tend to ''average down'' the beam brightness. Particle simulation work indicates that beam brightness can be significantly improved by simply reducing the injector transport magnetic field and losing peak transport current, i.e., only transporting that high brightness portion of the total current. The simulation results shown in Figure 8 suggest that beam brightness can be increased perhaps a factor of 5 or more simply by ''tuning for brightness'' rather than tuning for peak transported current. If this can indeed be experimentally realized and the resulting beam matched onto accelerator transport (magnetic and/or laser guided) without emittance degradation then simple field emission cathodes would, at least in the immediately near term, saisfy the needs for 10 micron FEL experiments. 8 refs., 8 figs.

  4. Acceleration of the LHC commissioning tests

    2008-01-01

    The quadrupole and main dipole circuits have been powered up to 10,200 amps in Sector 4-5. Sector 5-6 is currently being cooled and will be the next to undergo electrical tests, which will be stepped up over the next few weeks.

  5. The Next Linear Collider test accelerator: Status and results

    At SLAC, the authors are pursuing the design of a Next Linear Collider (NLC) which would begin with a center-of-mass energy of 0.5 TeV, and would be upgradable to 1.0 TeV and beyond. To achieve this high energy, for the past several years they have been working on the development of a high-gradient 11.4-GHz (X-band) linear accelerator for the main linac of the collider. In this paper, they present the status and initial results from the ''Next Linear Collider Test Accelerator'' (NLCTA). The goal of the NLCTA is to model the high gradient linac of the NLC. It incorporates the new technologies of X-band accelerator structures, rf pulse compression systems and high-power klystrons into a 0.5 to 1.0 GeV linac which is a test bed for beam dynamics issues related to high-gradient acceleration

  6. Electrical performance characteristics of the SSC Accelerator System String Test

    The intent of the Accelerator System String Test (ASST) is to obtain data for model verification and information on the magnitudes of pressures and voltages encountered in an accelerator environment. The ASST milestone run was achieved during July and August, 1992 and consisted of demonstrating the accelerator components could be configured together as a system operating at full current. Following the milestone run, the string was warmed to counteract some design flaws that impeded the operational range. The string was again cooled to cryogenic temperatures in October, and a comprehensive power testing program was conducted through the end of January, 1993. This paper describes how the collider arc components operate in an accelerator environment during quenches induced by firing both strip heaters and spot heaters. Evaluation of the data illustrates how variations in the design parameters on magnets used in a string environment can impact system performance

  7. Electrical performance characteristics of the SSC accelerator system string test

    The intent of the Accelerator System String Test (ASST) is to obtain data for model verification and information on the magnitudes of pressures and voltages encountered in an accelerator environment. The ASST milestone run was achieved during July and August, 1992 and consisted of demonstrating that the accelerator components could be configured together as a system operating at full current. Following the milestone run, the string was warmed to counteract some design flaws that impeded the operational range. The string was again cooled to cryogenic temperatures in October, and a comprehensive power testing program was conducted through the end of January, 1993. This paper describes how the collider arc components operate in an accelerator environment during quenches induced by firing both strip heaters and spot heaters. Evaluation of the data illustrates how variations in the design parameters on magnets used in a string environment can impact system performance

  8. A comparative study of accelerated tests to simulate atmospheric corrosion

    In this study, specimens coated with five organic coating systems were exposed to accelerated tests for periods up to 2000 hours, and also to weathering for two years and six months. The accelerated tests consisted of the salt spray test, according to ASTM B-117; Prohesion (ASTM G 85-98 annex 5A); Prohesion combined with cyclic exposure to UV-A radiation and condensation; 'Prohchuva' a test described by ASTM G 85-98 using a salt spray with composition that simulated the acid rain of Sao Paulo, but one thousand times more concentrated, and 'Prohchuva' combined with cyclic exposure to UV-A radiation and condensation. The coated specimens were exposed with and without incision to expose the substrate. The onset and progress of corrosion at and of the exposed metallic surface, besides coating degradation, were followed by visual observation, and photographs were taken. The coating systems were classified according to the extent of corrosion protection given to the substrate, using a method based on ASTM standards D-610, D-714, D-1654 and D-3359. The rankings of the coatings obtained from accelerated tests and weathering were compared and contrasted with classification of the same systems obtained from literature, for specimens exposed to an industrial atmosphere. Coating degradation was strongly dependent on the test, and could be attributed to differences in test conditions. The best correlation between accelerated test and weathering was found for the test Prohesion alternated with cycles of exposure to UV-A radiation and condensation. (author)

  9. The Advanced Superconducting Test Accelerator at Fermilab: Science Program

    Piot, Philippe [Fermilab; Harms, Elvin [Fermilab; Henderson, Stuart [Fermilab; Leibfritz, Jerry [Fermilab; Nagaitsev, Sergei [Fermilab; Shiltsev, Vladimir [Fermilab; Valishev, Alexander [Fermilab

    2014-07-01

    The Advanced Superconducting Test Accelerator (ASTA) currently in commissioning phase at Fermilab is foreseen to support a broad range of beam-based experiments to study fundamental limitations to beam intensity and to develop novel approaches to particle-beam generation, acceleration and manipulation. ASTA incorporates a superconducting radiofrequency (SCRF) linac coupled to a flexible high-brightness photoinjector. The facility also includes a small-circumference storage ring capable of storing electrons or protons. This report summarizes the facility capabilities, and provide an overview of the accelerator-science researches to be enabled.

  10. Testing General Relativity With Laser Accelerated Electron Beams

    Gergely, L. Á.; Harko, T.

    2012-01-01

    Electron accelerations of the order of $10^{21} g$ obtained by laser fields open up the possibility of experimentally testing one of the cornerstones of general relativity, the weak equivalence principle, which states that the local effects of a gravitational field are indistinguishable from those sensed by a properly accelerated observer in flat space-time. We illustrate how this can be done by solving the Einstein equations in vacuum and integrating the geodesic equations of motion for a un...

  11. The Accelerated Test of Chloride Permeability of Concrete

    TAN Ke-feng; ODD E Gjφrv

    2003-01-01

    The availability of accelerated chloride permeability test and the effect of w/c ratio, incorporation of silica fume, maximum aggregate size and aggregate type on the chloride permeability were studied. The mathematic analysis certifies that there is a linear relationship between accelerated test and natural diffusion. Test results show that the chloride permeability of concrete increases as w/c ratio increases whilst a limited amount of replacement of cement with silica fume, the chloride permeability decreases dramatically. The maximum aggregate size in the range of 8 to 25 mm seems also affect chloride permeability but with a much less significant level. The chloride permeability of silica fume lightweight aggregate concrete is very low, especially the concrete made with dry lightweight concrete. The chloride permeability can be evaluated by this accelerated test method.

  12. Nuclear-waste-package materials degradation modes and accelerated testing

    This report reviews the materials degradation modes that may affect the long-term behavior of waste packages for the containment of nuclear waste. It recommends an approach to accelerated testing that can lead to the qualification of waste package materials in specific repository environments in times that are short relative to the time period over which the waste package is expected to provide containment. This report is not a testing plan but rather discusses the direction for research that might be considered in developing plans for accelerated testing of waste package materials and waste forms

  13. Evaluation of an Accelerated ELDRS Test Using Molecular Hydrogen

    Pease, Ronald L.; Adell, Philippe C.; Rax, Bernard; McClure, Steven; Barnaby, Hugh J.; Kruckmeyer, Kirby; Triggs, B.

    2011-01-01

    An accelerated total ionizing dose (TID) hardness assurance test for enhanced low dose rate sensitive (ELDRS) bipolar linear circuits, using high dose rate tests on parts that have been exposed to molecular hydrogen, has been proposed and demonstrated on several ELDRS part types. In this study several radiation-hardened "ELDRS-free" part types have been tested using this same approach to see if the test is overly conservative.

  14. Acceleration test of heavy-ion with TIT RFQ linac

    A heavy-ion acceleration system with the TIT-RFQ has been developed. The TIT-RFQ was designed to accelerate particles with a charge to mass ratio ε ≥ 1/16, as it was, the kind of particles was limited because of the insufficient withstanding voltage of the beam injection equipment. In order to solve this problem, the development of the new system was planed, and the work has been carried out since last year. By using this system, the first acceleration of N+ beam was observed in January this year; however, the beam intensity was insufficient. Some problems were pointed out, and the synchronous circuit of a RF pulse was constructed up to now. By using this circuit, the increase of the beam intensity was observed in the second acceleration test in this summer. (author)

  15. Automatic testing of medium-frequency acceleration transducers

    An automatic test bench for medium-frequency acceleration transducers employing a method of comparison is described. The following points are discussed: the measurement possibilities of this bench in the frequency range 10Hz-10kHz and for applied acceleration levels of 1000m.s-2 or below; the transducer parameters checked; the uncertainties on the measurement of these parameters. The test procedure is described in detail and illustrated by a concrete case showing the particular form of presentation of the results

  16. Mechanical stability study for Integrable Optics Test Accelerator at Fermilab

    McGee, M. W.; Andrews, R; Carlson, K.; Leibfritz, J.; Nobrega, L.; Valishev, A.

    2016-01-01

    The Integrable Optics Test Accelerator (IOTA) is proposed for operation at Fermilab. The goal of IOTA is to create practical nonlinear accelerator focusing systems with a large frequency spread and stable particle motion. The IOTA is a 40 m circumference, 150 MeV (e-), 2.5 MeV (p+) diagnostic test ring. A heavy low frequency steel floor girder is proposed as the primary tier for IOTA device component support. Two design lengths; (8) 3.96 m and (2) 3.1 m long girders with identical cross secti...

  17. High current electron linacs (advanced test accelerator/experimental test accelerator)

    The high current induction accelerator development at the Lawrence Livermore National Laboratory is described. The ATA facility is designed for 10 kA peak currents, 50 nsec pulse lengths and 50 MeV energies. At this time, half of the design current has been accelerated through the entire machine to particle energies of about 45 MeV. Current problem areas and operational experience to date will be discussed. Several key technical areas required development for the ATA machine; this report will survey these developments. The control of transverse beam instabilities required an accelerating cavity design with very low Q. Electron sources capable of 10 kA operation at high rep rates were developed using a plasma sparkboard approach. The pulse power systems on ATA, using the same type of spark gap switches as ETA, have exhibited excellent operational reliability

  18. An accelerated test method for efflorescence in clay bricks

    An investigation into the creation of accelerated efflorescence in clay bricks was undertaken with a view to creating a viable test procedure for determining efflorescence potential. The testing programme incorporated ambient conditions similar to those which promote efflorescence growth in bricks in use. Theoretical investigations into the physical mechanism underlying the creation of efflorescence directed the attempts to accelerate the process. It was found that calcium sulphate efflorescence could not be sufficiently accelerated such that a useful efflorescence test procedure could be proposed. The inability to produce accelerated efflorescence in brick samples was attributed to limitations associated with time dependent salt diffusion in the efflorescence mechanism. The preliminary testing that was undertaken into the creation of efflorescence prompted the use of acid assisted methods to accelerate efflorescence. The acid assisted method that was adopted to provide a possible indication of efflorescence potential relies upon the transformation of low solubility calcium to a more soluble form. The movement of the transformed salt is then induced by cyclic temperature exposure at temperatures similar to those experienced in Spring. The appearance of the transformed calcium salt on the surface of the brick specimen provides an indication of the efflorescence potential. Brick piers constructed on an exposed site and monitored over a 12 month period provided information on the validity of the acid assisted test method. The efflorescence observed on the piers correlated well with that predicted by the acid assisted test, suggesting that the new test has the potential to accurately predict the efflorescence potential of clay bricks Relationships between other properties such as air permeability, sorptivity and tensile strength were investigated such that an alternative method of predicting efflorescence could be achieved. It was found that (within the bounds of the

  19. Quick setup of test unit for accelerator control system

    Testing a single hardware unit of an accelerator control system often requires the setup of a program with graphical user interface. Developing a dedicated application for a specific hardware unit test could be time consuming and the application may become obsolete after the unit tests. This paper documents a methodology for quick design and setup of an interface focused on performing unit tests of accelerator equipment with minimum programming work. The method has three components. The first is a generic accelerator device object (ADO) manager which can be used to setup, store, and log testing controls parameters for any unit testing system. The second involves the design of a TAPE (Tool for Automated Procedure Execution) sequence file that specifies and implements all te testing and control logic. The sting third is the design of a PET (parameter editing tool) page that provides the unit tester with all the necessary control parameters required for testing. This approach has been used for testing the horizontal plane of the Stochastic Cooling Motion Control System at RHIC.

  20. The BNL Accelerator Test Facility and experimental program

    The Accelerator Test Facility (ATF) at BNL is a users' facility for experiments in Accelerator and Beam Physics. The ATF provides high brightness electron beams and high power laser pulses synchronized to the electron beam, suitable for studies of new methods of high gradient acceleration and state of the art free electron lasers. The electrons are produced by a laser photocathode rf gun and accelerated to 50 to 100 MeV by two traveling wave accelerator sections. The lasers include a 10 mJ, 10 ps Nd:YAG laser and a 100 mJ, 10 ps CO2 laser. A number of users from National Laboratories, universities and industry take part in experiments at the ATF. The experimental program includes various acceleration schemes, Free-Electron Laser experiments and a program on the development of high brightness electron beams. The AFT's experimental program commenced in early 1991 at an energy of about 4 MeV. The full program, with 50 MeV and the High power laser will begin operation this year. 28 refs., 4 figs

  1. Experience on high voltage testing and conditioning of accelerator tube for 3 MeV DC accelerator

    In DC Electron Beam Accelerator, accelerating potentials are generated using high voltage multiplier column. Accelerating potentials are uniformly graded to the accelerator tubes for accelerating the electron to attain the required energy. 3 MeV DC Accelerator is in the advance stages of commissioning at Electron Beam Centre Kharghar, Navi Mumbai. It has 10 numbers of accelerating tube each rated for 335 kVdc in 6 kg/cm2 SF6 gas environment outside and vacuum better than 10-7 mbar inside the tube. For safe and reliable operation of the accelerator, all the dynode gaps have to be conditioned and tested for high voltage withstand capability. Accelerating Tube Test Facility (ATTF) was developed for the testing and HV Conditioning of the accelerator tube. Tubes are conditioned with plasma, baking and application of ascending high Voltages. This paper describes the experience on the high voltage conditioning and testing of the accelerator tube of 3 MeV DC Accelerator. The accelerator has been successfully tested at 1 MeV and 10 kW beam power and 1.8 MeV at no load. (author)

  2. Comment on "Testing Planck-Scale Gravity with Accelerators"

    Kalaydzhyan, Tigran

    2016-01-01

    We challenge the analysis and conclusions of the paper Phys. Rev. Lett. 109, 141103 (2012) by V. Gharibyan on the tests of Planck-scale gravity with accelerators. The main objective of the Comment is the observation that the explored domain of "quantum gravity" parameters is already ruled out experimentally from, e.g., absence of the vacuum Cherenkov radiation.

  3. Step-Stress Accelerated Degradation Testing for Solar Reflectors: Preprint

    Jones, W.; Elmore, R.; Lee, J.; Kennedy, C.

    2011-09-01

    To meet the challenge to reduce the cost of electricity generated with concentrating solar power (CSP) new low-cost reflector materials are being developed including metalized polymer reflectors and must be tested and validated against appropriate failure mechanisms. We explore the application of testing methods and statistical inference techniques for quantifying estimates and improving lifetimes of concentrating solar power (CSP) reflectors associated with failure mechanisms initiated by exposure to the ultraviolet (UV) part of the solar spectrum. In general, a suite of durability and reliability tests are available for testing a variety of failure mechanisms where the results of a set are required to understand overall lifetime of a CSP reflector. We will focus on the use of the Ultra-Accelerated Weathering System (UAWS) as a testing device for assessing various degradation patterns attributable to accelerated UV exposure. Depending on number of samples, test conditions, degradation and failure patterns, test results may be used to derive insight into failure mechanisms, associated physical parameters, lifetimes and uncertainties. In the most complicated case warranting advanced planning and statistical inference, step-stress accelerated degradation (SSADT) methods may be applied.

  4. Accelerated aging tests of liners for uranium mill tailings disposal

    Barnes, S.M.; Buelt, J.L.; Hale, V.Q.

    1981-11-01

    This document describes the results of accelerated aging tests to determine the long-term effectiveness of selected impoundment liner materials in a uranium mill tailings environment. The study was sponsored by the US Department of Energy under the Uranium Mill Tailings Remedial Action Project. The study was designed to evaluate the need for, and the performance of, several candidate liners for isolating mill tailings leachate in conformance with proposed Environmental Protection Agency and Nuclear Regulatory Commission requirements. The liners were subjected to conditions known to accelerate the degradation mechanisms of the various liners. Also, a test environment was maintained that modeled the expected conditions at a mill tailings impoundment, including ground subsidence and the weight loading of tailings on the liners. A comparison of installation costs was also performed for the candidate liners. The laboratory testing and cost information prompted the selection of a catalytic airblown asphalt membrane and a sodium bentonite-amended soil for fiscal year 1981 field testing.

  5. Accelerated aging tests of liners for uranium mill tailings disposal

    This document describes the results of accelerated aging tests to determine the long-term effectiveness of selected impoundment liner materials in a uranium mill tailings environment. The study was sponsored by the US Department of Energy under the Uranium Mill Tailings Remedial Action Project. The study was designed to evaluate the need for, and the performance of, several candidate liners for isolating mill tailings leachate in conformance with proposed Environmental Protection Agency and Nuclear Regulatory Commission requirements. The liners were subjected to conditions known to accelerate the degradation mechanisms of the various liners. Also, a test environment was maintained that modeled the expected conditions at a mill tailings impoundment, including ground subsidence and the weight loading of tailings on the liners. A comparison of installation costs was also performed for the candidate liners. The laboratory testing and cost information prompted the selection of a catalytic airblown asphalt membrane and a sodium bentonite-amended soil for fiscal year 1981 field testing

  6. Optical fiber feasibility study in Accelerated Pavement Testing facility

    Bueche, N.; Rychen, P.; Dumont, A.-G.; Santagata, E.

    2009-01-01

    The presented research has been carried out within the European project Intelligent Roads (INTRO). The major objective followed was to assess the potential of optical fiber for pavement monitoring in comparison with classical strain gauges. Thus, both measurement devices have been tested under the same conditions in a full scale Accelerated Pavement Testing (APT) at LAVOC. This facility allows the user to control different parameters such as loading configuration and temperature and, as a mat...

  7. Free-electron laser results from the Advanced Test Accelerator

    PALADIN is a 10.6-μm FEL amplifier experiment operating at the Lawrence Livermore National Laboratory's Advanced Test Accelerator, an induction linear accelerator designed to produce a 45-MeV, 10-kA electron beam. With a 15-m long wiggler, PALADIN demonstrated 27 dB of exponential gain from a 14-kW input signal. With a 5-MW input signal, the amplifier saturated after 10 dB of gain. The exponentially growing signal in the unsaturated amplifier was clearly seen to be gain guided by the electron beam. 7 refs., 8 figs

  8. Operation of the graded-β electron test accelerator

    The Electron Test Accelerator has been built to model the behaviour of the high energy portion of a proton linear accelerator which would be suitable for breeding fissile material. The test accelerator and its control systems have been tested at 100% duty factor producing a beam of electrons at 1.5 MeV and currents up to 20 mA where the incident rf power is shared equally between the structure dissipation and the beam loading. The structure has performed satisfactorily in all respects at dissipation power densities up to 5 kW/cell where the mean energy gradient was 1.1 MeV/m. Experiments have been done on the beam loading effects in the coupling of the transmission line to the cavity, the amplitude depression in and phase tilt along the structure, and the phase lag of the structure field. The phase acceptance, the variation of transmission with buncher-accelerator phase shift and the beam energy spread are in qualitative agreement with beam dynamics calculations. (author)

  9. High-Voltage Terminal Test of Test Stand for 1-MV Electrostatic Accelerator

    Park, Sae-Hoon

    2015-01-01

    The Korea Multipurpose Accelerator Complex (KOMAC) has been developing a 300-kV test stand for a 1-MV electrostatic accelerator ion source. The ion source and accelerating tube will be installed in a high-pressure vessel. The ion source in the high-pressure vessel is required to have a high reliability. The test stand has been proposed and developed to confirm the stable operating conditions of the ion source. The ion source will be tested at the test stand to verify the long-time operating conditions. The test stand comprises a 300-kV high-voltage terminal, a battery for the ion-source power, a 60-Hz inverter, 200-MHz RF power, a 5-kV extraction power supply, a 300-kV accelerating tube, and a vacuum system. The results of the 300-kV high-voltage terminal tests are presented in this paper.

  10. Klystron pulse modulator of linear electron accelerator: test results

    Z. Zimek

    2009-12-01

    Full Text Available Purpose: The purpose of the paper is to describe Klystron pulse modulator of linear electron accelerator.Design/methodology/approach: TH-2158 klystron modulator experimental model is based on semiconductor switch HTS 181-160 FI (acceptable current load 1600 A, and voltage up to 18 kV. The results of test measurements carried out during modulator starting up period are presented in this work. TH-2158 klystron was used as a load. The klystron was connected to the second winding of the pulse HV transformer with 1:10 windings turn ratio. The examined modulator is equipped with safety shutdown circuitry for protection against current overload that may appear at IGBT switch in the case of short-circuiting happened in klystron and waveguide system.Findings: Linear electron accelerator type LAE 10/15 with electron energy 10 MeV and beam power up to 15 kW was designed and completed at Institute of Nuclear Chemistry and Technology. This accelerator was installed in facility for radiation sterilization single use medical devices, implants and tissue grafts. The standing wave accelerating section was selected. Microwave energy used for accelerating process is provided by klystron type TH-2158 working at frequency 2856 MHz.Practical implications: Described HV pulse modulator which designed and constructed for klystron TH-2158 was preliminary tested to evaluate the quality of the klystron HV and load current pulses and optimized selected component parameters. Obtained experimental results are better than those which were predicted by computer simulation method.Originality/value: Description of Klystron pulse modulator of linear electron accelerator.

  11. A general Bayes weibull inference model for accelerated life testing

    This article presents the development of a general Bayes inference model for accelerated life testing. The failure times at a constant stress level are assumed to belong to a Weibull distribution, but the specification of strict adherence to a parametric time-transformation function is not required. Rather, prior information is used to indirectly define a multivariate prior distribution for the scale parameters at the various stress levels and the common shape parameter. Using the approach, Bayes point estimates as well as probability statements for use-stress (and accelerated) life parameters may be inferred from a host of testing scenarios. The inference procedure accommodates both the interval data sampling strategy and type I censored sampling strategy for the collection of ALT test data. The inference procedure uses the well-known MCMC (Markov Chain Monte Carlo) methods to derive posterior approximations. The approach is illustrated with an example

  12. Next Linear Collider Test Accelerator conceptual design report

    This document presents the scientific justification and the conceptual design for the open-quotes Next Linear Collider Test Acceleratorclose quotes (NLCTA) at SLAC. The goals of the NLCTA are to integrate the new technologies of X-band accelerator structures and rf systems being developed for the Next Linear Collider, to measure the growth of the open-quotes dark currentclose quotes generated by rf field emission in the accelerator, to demonstrate multi-bunch beam-loading energy compensation and suppression of higher-order deflecting modes, and to measure any transverse components of the accelerating field. The NLCTA will be a 42-meter-long beam line consisting, consecutively, of a thermionic-cathode gun, an X-band buncher, a magnetic chicane, six 1.8-meter-long sections of 11.4-GHz accelerator structure, and a magnetic spectrometer. Initially, the unloaded accelerating gradient will be 50 MV/m. A higher-gradient upgrade option eventually would increase the unloaded gradient to 100 MV/m

  13. Mechanical stability study for Integrable Optics Test Accelerator at Fermilab

    McGee, M W; Carlson, K; Leibfritz, J; Nobrega, L; Valishev, A

    2016-01-01

    The Integrable Optics Test Accelerator (IOTA) is proposed for operation at Fermilab. The goal of IOTA is to create practical nonlinear accelerator focusing systems with a large frequency spread and stable particle motion. The IOTA is a 40 m circumference, 150 MeV (e-), 2.5 MeV (p+) diagnostic test ring. A heavy low frequency steel floor girder is proposed as the primary tier for IOTA device component support. Two design lengths; (8) 3.96 m and (2) 3.1 m long girders with identical cross section completely encompass the ring. This study focuses on the 3.96 m length girder and the development of a working prototype. Hydrostatic Level Sensor (HLS), temperature, metrology and fast motion measurements characterize the anticipated mechanical stability of the IOTA ring.

  14. European accelerator facilities for single event effects testing

    Adams, L.; Nickson, R.; Harboe-Sorensen, R. [ESA-ESTEC, Noordwijk (Netherlands); Hajdas, W.; Berger, G.

    1997-03-01

    Single event effects are an important hazard to spacecraft and payloads. The advances in component technology, with shrinking dimensions and increasing complexity will give even more importance to single event effects in the future. The ground test facilities are complex and expensive and the complexities of installing a facility are compounded by the requirement that maximum control is to be exercised by users largely unfamiliar with accelerator technology. The PIF and the HIF are the result of experience gained in the field of single event effects testing and represent a unique collaboration between space technology and accelerator experts. Both facilities form an essential part of the European infrastructure supporting space projects. (J.P.N.)

  15. Mechanical Stability Study for Integrable Optics Test Accelerator at Fermilab

    McGee, Mike [Fermilab; Andrews, Richard [Fermilab; Carlson, Kermit [Fermilab; Leibfritz, Jerry [Fermilab; Nobrega, Lucy [Fermilab; Valishev, Alexander [Fermilab

    2016-07-01

    The Integrable Optics Test Accelerator (IOTA) is proposed for operation at Fermilab. The goal of IOTA is to create practical nonlinear accelerator focusing systems with a large frequency spread and stable particle motion. The IOTA is a 40 m circumference, 150 MeV (e-), 2.5 MeV (p⁺) diagnostic test ring. A heavy low frequency steel floor girder is proposed as the primary tier for IOTA device component support. Two design lengths; (8) 4 m and (2) 2.8 m long girders with identical cross section completely encompass the ring. This study focuses on the 4 m length girder and the development of a working prototype. Hydrostatic Level Sensor (HLS), temperature, metrology and fast motion measurements characterize the anticipated mechanical stability of the IOTA ring.

  16. Design of Accelerated Fatigue Tests for Flame Free Refrigeration Fittings

    Wilson, Michael; Bowers, Chad D.

    2014-01-01

    Refrigerant leakage from failed braze joints is a multi-billion dollar problem for the global HVAC&R industry. Leaks are typically caused due to mechanical fatigue from extreme pressure cycling, temperature cycling including exposure to freeze/thaw cycles, or vibrational wear induced from rotating electrical machinery. Three tests to accelerate mechanical fatigue were devised to simulate real world extreme conditions to determine possible failure modes of refrigerant components. The first tes...

  17. Brookhaven Accelerator Test Facility photocathode gun and transport beamline

    We present an analysis of the electron beam emitted from a laser driven photocathode injector (Gun, operating at 2856 MHZ), through a Transport beamline, to the LINAC entrance for the Brookhaven Accelerator Test Facility (ATF). The beam parameters including beam energy, and emittance are calculated. Some of our results, are tabulated and the phase plots of the beam parameters, from Cathode, through the Transport line elements, to the LINAC entrance, are shown

  18. Development of an accelerated test for Internal Sulfate Attack study

    Khelil Nacim

    2014-04-01

    Full Text Available Internal Sulfate Attack (ISA is a pathology that occurs under certain conditions in concrete having undergone heating above 70 °C at early age (through heating in pre-casting industry or due to hydration in large concrete parts. This reaction deemed very slow, numerous methods to speed up reactions leading to delayed ettringite formation have been developed. These methods are all based on the material damage. Another type of test is currently under development. It is based on rehabilitation techniques such as electrochemical chloride extraction (ECE in order to accelerate the leaching of alkalis that could be one of the triggers of the pathology. The study presented in this paper focused on concrete specimens prepared from cement (CEM I 52.5 N enriched with Na2SO4. These concretes have undergone a heat treatment typical of those used in precast plants (up to 24 hours with a maximum temperature of 80 °C. Various paths were explored for the development of the accelerated test. The first results showed that it was necessary to use a removable titanium anode ruthenium anode instead of stainless steel embedded in the concrete. Then tests with de-ionized water as the solute to the cathode did not accelerate the onset of expansions. The experiment has been modified and potassium carbonate was added to the solution. This modification didn’t show any significant improvement, and other experiments are being carried out to explain this result.

  19. Accelerated Creep Testing of High Strength Aramid Webbing

    Jones, Thomas C.; Doggett, William R.; Stnfield, Clarence E.; Valverde, Omar

    2012-01-01

    A series of preliminary accelerated creep tests were performed on four variants of 12K and 24K lbf rated Vectran webbing to help develop an accelerated creep test methodology and analysis capability for high strength aramid webbings. The variants included pristine, aged, folded and stitched samples. This class of webbings is used in the restraint layer of habitable, inflatable space structures, for which the lifetime properties are currently not well characterized. The Stepped Isothermal Method was used to accelerate the creep life of the webbings and a novel stereo photogrammetry system was used to measure the full-field strains. A custom MATLAB code is described, and used to reduce the strain data to produce master creep curves for the test samples. Initial results show good correlation between replicates; however, it is clear that a larger number of samples are needed to build confidence in the consistency of the results. It is noted that local fiber breaks affect the creep response in a similar manner to increasing the load, thus raising the creep rate and reducing the time to creep failure. The stitched webbings produced the highest variance between replicates, due to the combination of higher local stresses and thread-on-fiber damage. Large variability in the strength of the webbings is also shown to have an impact on the range of predicted creep life.

  20. An Asset Test of the CLIC Accelerating Structure

    Transverse wakefield suppression in the CLIC (Compact Linear Collider) multibunch accelerating structure, called the TDS (Tapered Damped Structure), is achieved primarily through heavy damping. In order to verify the performance of the TDS design and the validity of the theoretical tools used to model it, a 15 GHz version of the TDS has been constructed and tested in the ASSET facility at SLAC. The test has directly demonstrated transverse wakefield suppression of over a factor 100, with an excellent agreement between the measured and the calculated wakefield

  1. Database requirements for the Advanced Test Accelerator project

    The database requirements for the Advanced Test Accelerator (ATA) project are outlined. ATA is a state-of-the-art electron accelerator capable of producing energetic (50 million electron volt), high current (10,000 ampere), short pulse (70 billionths of a second) beams of electrons for a wide variety of applications. Databasing is required for two applications. First, the description of the configuration of facility itself requires an extended database. Second, experimental data gathered from the facility must be organized and managed to insure its full utilization. The two applications are intimately related since the acquisition and analysis of experimental data requires knowledge of the system configuration. This report reviews the needs of the ATA program and current implementation, intentions, and desires. These database applications have several unique aspects which are of interest and will be highlighted. The features desired in an ultimate database system are outlined. 3 references, 5 figures

  2. Beam loading and cavity compensation for the Ground Test Accelerator

    The Ground Test Accelerator (GTA) will be heavily beam-loaded H- linac with tight tolerances on accelerating field parameters. The methods used in modeling the effects of beam loading in this machine are described. The response of the cavity to both beam and radio-frequency (RF) drive stimulus is derived, including the effects of cavity detuning. This derivation is not restricted to a small-signal approximation. An analytical method for synthesizing a predistortion network that decouples the amplitude and phase responses of the cavity is also outline. Simulation of performance, including beam loading, is achieved through use of a control system analysis software package. A straightforward method is presented for extrapolating this work to model large coupled structures with closely spaced parasitic modes. Results to date have enabled the RF control system designs for GTA to be optimized and have given insight into their operation. 6 refs., 10 figs

  3. Precise RF control system of the SCSS test accelerator

    We present development and performance of the low-level rf control system of the SCSS test accelerator. The low-level rf system consists of IQ modulators / demodulators and VME waveform generators / digitizers. Recent improvements of them established high-resolution phase and amplitude setting capabilities of 0.01 degree and 0.01%, respectively. In addition, temperature drifts of the injector acceleration cavities were reduced by tuning a precise temperature regulation system. The temperature fluctuation was improved to be 0.01 K rms. As a result, the rf phase and amplitude stabilities of sub-harmonic buncher cavities were achieved to be 0.02 degree rms and 0.03% rms, respectively. The saturated FEL radiation in the wavelength region of 50-60 nm is stably generated by this improvement. (author)

  4. Accelerated stress testing of amorphous silicon solar cells

    Stoddard, W. G.; Davis, C. W.; Lathrop, J. W.

    1985-01-01

    A technique for performing accelerated stress tests of large-area thin a-Si solar cells is presented. A computer-controlled short-interval test system employing low-cost ac-powered ELH illumination and a simulated a-Si reference cell (seven individually bandpass-filtered zero-biased crystalline PIN photodiodes) calibrated to the response of an a-Si control cell is described and illustrated with flow diagrams, drawings, and graphs. Preliminary results indicate that while most tests of a program developed for c-Si cells are applicable to a-Si cells, spurious degradation may appear in a-Si cells tested at temperatures above 130 C.

  5. Simulations and Vacuum Tests of a CLIC Accelerating Structure

    Garion, C

    2011-01-01

    The Compact LInear Collider, under study, is based on room temperature high gradient structures. The vacuum specificities of these cavities are low conductance, large surface areas and a non-baked system. The main issue is to reach UHV conditions (typically 10-7 Pa) in a system where the residual vacuum is driven by water outgassing. A finite element model based on an analogy thermal/vacuum has been built to estimate the vacuum profile in an accelerating structure. Vacuum tests are carried out in a dedicated set-up, the vacuum performances of different configurations are presented and compared with the predictions.

  6. Testing of accelerator dipoles in pressurized superfluid helium

    Two superconducting accelerator dipole magnets, with different internal construction features, have been tested in pressurized superfluid helium (1.8K, 1.2 atmosphere) as well as in regular pool boiling helium (4.4K, 1.2 atmosphere) helium. The coils of one magnet were moderately pre-stressed, and 4.2K design performance was rapidly achieved in the superfluid. The other magnet had very low coil pre-stress, reduced helium ventilation, and displayed degraded performance, even in the superfluid helium

  7. Metal and elastomer seal tests for accelerator applications

    The vacuum system of the Alternating Gradient Synchrotron (AGS) at Brookhaven National Laboratory has more than a thousand metal vacuum seals. Also, numerous elastomer seals are used throughout the AGS to seal large beam component chambers. An accelerator upgrade program is being implemented to reduce the AGS operating pressure by x100 and improve the reliability of the vacuum system. This paper describes work in progress on metal and elastomer vacuum seals to help meet those two objectives. Tests are reported on the sealing properties of a variety of metal seals used on different sealing surfaces. Results are also given on reversible sorption properties of certain elastomers. 16 refs., 6 figs., 4 tabs

  8. Accelerated aging of IG units : North American test methods

    Both Canadian and American standards have been in place for decades to determine argon gas concentration in insulating glass (IG) units. Efforts are underway to harmonize the IG standards to have acceptable test methods for the durability of IG units and to implement a single certification program for both Canada and the United States. One way to test the durability and integrity of the edge seal on IG units is to subject them to accelerated aging cycles in a controlled environment. This paper summarizes the Canadian, American and the harmonized test methods used in testing the integrity of the seal and the determination of argon gas in IG units. The Canadian standard (CAN/CGSB 12.8) encompasses the following tests: initial seal of units, initial dew point, initial argon concentration, failure analysis (water immersion test), weather cycling, volatile fogging (UV), dew point measurement after weather cycling, high humidity cycling, and final argon concentration. American ASTM E773 and ASTM E774 differ from the Canadian standard in the sequence of testing and the rating of IG units, creating problems for certification of units being shipped across the border. It was noted that adopting a single certification program for Canada and the United States would bring economic benefits to both consumers and manufacturers. 7 refs., 5 figs

  9. Bayesian optimal design of step stress accelerated degradation testing

    Xiaoyang Li; Mohammad Rezvanizaniani; Zhengzheng Ge; Mohamed Abuali; Jay Lee

    2015-01-01

    This study presents a Bayesian methodology for de-signing step stress accelerated degradation testing (SSADT) and its application to batteries. First, the simulation-based Bayesian de-sign framework for SSADT is presented. Then, by considering his-torical data, specific optimal objectives oriented Kul back–Leibler (KL) divergence is established. A numerical example is discussed to il ustrate the design approach. It is assumed that the degrada-tion model (or process) fol ows a drift Brownian motion;the accele-ration model fol ows Arrhenius equation; and the corresponding parameters fol ow normal and Gamma prior distributions. Using the Markov Chain Monte Carlo (MCMC) method and WinBUGS software, the comparison shows that KL divergence is better than quadratic loss for optimal criteria. Further, the effect of simulation outliers on the optimization plan is analyzed and the preferred sur-face fitting algorithm is chosen. At the end of the paper, a NASA lithium-ion battery dataset is used as historical information and the KL divergence oriented Bayesian design is compared with maxi-mum likelihood theory oriented local y optimal design. The results show that the proposed method can provide a much better testing plan for this engineering application.

  10. Mir Cooperative Solar Array Project Accelerated Life Thermal Cycling Test

    Hoffman, David J.; Scheiman, David A.

    1996-01-01

    The Mir Cooperative Solar Array (MCSA) project was a joint U.S./Russian effort to build a photovoltaic (PV) solar array and deliver it to the Russian space station Mir. The MCSA will be used to increase the electrical power on Mir and provide PV array performance data in support of Phase 1 of the International Space Station. The MCSA was brought to Mir by space shuttle Atlantis in November 1995. This report describes an accelerated thermal life cycle test which was performed on two samples of the MCSA. In eight months time, two MCSA solar array 'mini' panel test articles were simultaneously put through 24,000 thermal cycles. There was no significant degradation in the structural integrity of the test articles and no electrical degradation, not including one cell damaged early and removed from consideration. The nature of the performance degradation caused by this one cell is briefly discussed. As a result of this test, changes were made to improve some aspects of the solar cell coupon-to-support frame interface on the flight unit. It was concluded from the results that the integration of the U.S. solar cell modules with the Russian support structure would be able to withstand at least 24,000 thermal cycles (4 years on-orbit). This was considered a successful development test.

  11. Power-conditioning system for the Advanced Test Accelerator

    The Advanced Test Accelerator (ATA) is a pulsed, linear induction, electron accelerator currently under construction and nearing completion at Lawrence Livermore National Laboratory's Site 300 near Livermore, California. The ATA is a 50 MeV, 10 kA machine capable of generating electron beam pulses at a 1 kHz rate in a 10 pulse burst, 5 pps average, with a pulse width of 70 ns FWHM. Ten 18 kV power supplies are used to charge 25 capacitor banks with a total energy storage of 8 megajoules. Energy is transferred from the capacitor banks in 500 microsecond pulses through 25 Command Resonant Charge units (CRC) to 233 Thyratron Switch Chassis. Each Thyratron Switch Chassis contains a 2.5 microfarad capacitor and is charged to 25 kV (780 joules) with voltage regulation of +- .05%. These capacitors are switched into 10:1 step-up resonant transformers to charge 233 Blumleins to 250 kV in 20 microseconds. A magnetic modulator is used instead of a Blumlein to drive the grid of the injector

  12. Cosmic acceleration without dark energy: background tests and thermodynamic analysis

    A cosmic scenario with gravitationally induced particle creation is proposed. In this model the Universe evolves from an early to a late time de Sitter era, with the recent accelerating phase driven only by the negative creation pressure associated with the cold dark matter component. The model can be interpreted as an attempt to reduce the so-called cosmic sector (dark matter plus dark energy) and relate the two cosmic accelerating phases (early and late time de Sitter expansions). A detailed thermodynamic analysis including possible quantum corrections is also carried out. For a very wide range of the free parameters, it is found that the model presents the expected behavior of an ordinary macroscopic system in the sense that it approaches thermodynamic equilibrium in the long run (i.e., as it nears the second de Sitter phase). Moreover, an upper bound is found for the Gibbons–Hawking temperature of the primordial de Sitter phase. Finally, when confronted with the recent observational data, the current 'quasi'-de Sitter era, as predicted by the model, is seen to pass very comfortably the cosmic background tests

  13. A flexible and configurable system to test accelerator magnets

    Jerzy M. Nogiec et al.

    2001-07-20

    Fermilab's accelerator magnet R and D programs, including production of superconducting high gradient quadrupoles for the LHC insertion regions, require rigorous yet flexible magnetic measurement systems. Measurement systems must be capable of handling various types of hardware and extensible to all measurement technologies and analysis algorithms. A tailorable software system that satisfies these requirements is discussed. This single system, capable of distributed parallel signal processing, is built on top of a flexible component-based framework that allows for easy reconfiguration and run-time modification. Both core and domain-specific components can be assembled into various magnet test or analysis systems. The system configured to comprise a rotating coil harmonics measurement is presented. Technologies as Java, OODB, XML, JavaBeans, software bus and component-based architectures are used.

  14. Linear Accelerator Test Facility at LNF Conceptual Design Report

    Valente, Paolo; Bolli, Bruno; Buonomo, Bruno; Cantarella, Sergio; Ceccarelli, Riccardo; Cecchinelli, Alberto; Cerafogli, Oreste; Clementi, Renato; Di Giulio, Claudio; Esposito, Adolfo; Frasciello, Oscar; Foggetta, Luca; Ghigo, Andrea; Incremona, Simona; Iungo, Franco; Mascio, Roberto; Martelli, Stefano; Piermarini, Graziano; Sabbatini, Lucia; Sardone, Franco; Sensolini, Giancarlo; Ricci, Ruggero; Rossi, Luis Antonio; Rotundo, Ugo; Stella, Angelo; Strabioli, Serena; Zarlenga, Raffaele

    2016-01-01

    Test beam and irradiation facilities are the key enabling infrastructures for research in high energy physics (HEP) and astro-particles. In the last 11 years the Beam-Test Facility (BTF) of the DA{\\Phi}NE accelerator complex in the Frascati laboratory has gained an important role in the European infrastructures devoted to the development and testing of particle detectors. At the same time the BTF operation has been largely shadowed, in terms of resources, by the running of the DA{\\Phi}NE electron-positron collider. The present proposal is aimed at improving the present performance of the facility from two different points of view: extending the range of application for the LINAC beam extracted to the BTF lines, in particular in the (in some sense opposite) directions of hosting fundamental physics and providing electron irradiation also for industrial users; extending the life of the LINAC beyond or independently from its use as injector of the DA{\\Phi}NE collider, as it is also a key element of the electron/...

  15. Advanced Beamline Design for Fermilab's Advanced Superconducting Test Accelerator

    Prokop, Christopher [Northern Illinois Univ., DeKalb, IL (United States)

    2014-01-01

    The Advanced Superconducting Test Accelerator (ASTA) at Fermilab is a new electron accelerator currently in the commissioning stage. In addition to testing superconducting accelerating cavities for future accelerators, it is foreseen to support a variety of Advanced Accelerator R&D (AARD) experiments. Producing the required electron bunches with the expected flexibility is challenging. The goal of this dissertation is to explore via numerical simulations new accelerator beamlines that can enable the advanced manipulation of electron bunches. The work especially includes the design of a low-energy bunch compressor and a study of transverse-to-longitudinal phase space exchangers.

  16. Beam test of multi-bunch energy compensation system in the accelerator test facility at KEK

    A beam test of the multi-bunch energy compensation system (ECS) was performed using the ΔF method with the 2856±4.327 HMz accelerating structures in the accelerator test facility (ATF) at KEK. The 1.54 GeV S-band linac of the ATF was designed to accelerate a multi-bunch beam the consists of 20 bunches with 2.8 ns spacing. The multi-bunch beam with 2.0 x 1010 electrons/bunch has an energy deviation of about 8.5% at the end of the linac due to transient beam loading without ECS. The ATF linac is the injector of the ATF damping ring (DR), whose energy acceptance is ±0.5%. The beam loading compensation system is necessary in the ATF linac for the successful injection of multi-bunch into DR. The rf system of the linac consists of 8 regular rf units with the SLED system and 2 ECS rf units without the SLED system. The accelerating structures of the regular units are driven at 2856 MHz and the 2 ECS structures are operated with slightly different rf frequencies of 2856±4.327 MHz. In the beam test, we have succeeded in compressing the multi-bunch energy spread within the energy acceptance of the DR using ΔF ECS. The principle of the beam loading compensation system of KEK-ATF and the experimental results are described in this paper. (author)

  17. Accelerated atmospheric corrosion testing of electroplated gold mirror coatings

    Chu, C.-T.; Alaan, D. R.; Taylor, D. P.

    2010-08-01

    Gold-coated mirrors are widely used in infrared optics for industrial, space, and military applications. These mirrors are often made of aluminum or beryllium substrates with polished nickel plating. Gold is deposited on the nickel layer by either electroplating or vacuum deposition processes. Atmospheric corrosion of gold-coated electrical connectors and contacts was a well-known problem in the electronic industry and studied extensively. However, there is limited literature data that correlates atmospheric corrosion to the optical properties of gold mirror coatings. In this paper, the atmospheric corrosion of different electroplated gold mirror coatings were investigated with an accelerated mixed flowing gas (MFG) test for up to 50 days. The MFG test utilizes a combination of low-level air pollutants, humidity, and temperatures to achieve a simulated indoor environment. Depending on the gold coating thickness, pore corrosion started to appear on samples after about 10 days of the MFG exposure. The corrosion behavior of the gold mirror coatings demonstrated the porous nature of the electroplated gold coatings as well as the variation of porosity to the coating thickness. The changes of optical properties of the gold mirrors were correlated to the morphology of corrosion features on the mirror surface.

  18. Accelerator

    The invention claims equipment for stabilizing the position of the front covers of the accelerator chamber in cyclic accelerators which significantly increases accelerator reliability. For stabilizing, it uses hydraulic cushions placed between the electromagnet pole pieces and the front chamber covers. The top and the bottom cushions are hydraulically connected. The cushions are disconnected and removed from the hydraulic line using valves. (J.P.)

  19. 15-16 MeV electron linear accelerators for nondestructive testing

    15-16 MeV electron linear accelerators for nondestructive testing (ND) are described. The accelerators are intended for ND of the articles with great thickness by means of radiographic, introscopic and tomographic methods. Main characteristics of these accelerators are presented. The automatic control system based on the PC compatible controllers is described in details

  20. Demonstration recommendations for accelerated testing of concrete decontamination methods

    A large number of aging US Department of Energy (DOE) surplus facilities located throughout the US require deactivation, decontamination, and decommissioning. Although several technologies are available commercially for concrete decontamination, emerging technologies with potential to reduce secondary waste and minimize the impact and risk to workers and the environment are needed. In response to these needs, the Accelerated Testing of Concrete Decontamination Methods project team described the nature and extent of contaminated concrete within the DOE complex and identified applicable emerging technologies. Existing information used to describe the nature and extent of contaminated concrete indicates that the most frequently occurring radiological contaminants are 137Cs, 238U (and its daughters), 60Co, 90Sr, and tritium. The total area of radionuclide-contaminated concrete within the DOE complex is estimated to be in the range of 7.9 x 108 ft2or approximately 18,000 acres. Concrete decontamination problems were matched with emerging technologies to recommend demonstrations considered to provide the most benefit to decontamination of concrete within the DOE complex. Emerging technologies with the most potential benefit were biological decontamination, electro-hydraulic scabbling, electrokinetics, and microwave scabbling

  1. LeRC rail accelerators: test designs and diagnostic techniques

    The feasibility of using rail accelerators for various in-space and to-space propulsion applications was investigated. A 1 meter, 24 sq mm bore accelerator was designed with the goal of demonstrating projectile velocities of 15 km/sec using a peak current of 200 kA. A second rail accelerator, 1 meter long with a 156.25 sq mm bore, was designed with clear polycarbonate sidewalls to permit visual observation of the plasma arc. A study of available diagnostic techniques and their application to the rail accelerator is presented. Specific topics of discussion include the use of interferometry and spectroscopy to examine the plasma armature as well as the use of optical sensors to measure rail displacement during acceleration. Standard diagnostics such as current and voltage measurements are also discussed. 15 references

  2. Status and plans for a SRF accelerator test faciliy at Fermilab

    Leibfritz, J.; R. Andrews; Carlson, K.; Chase, B.; Church, M.; HARMS, E.; Klebaner, A.; Kucera, M.; Lackey, S.; Martinez, A.; Nagaitsev, S.; Nobrega, L.; Piot, P; Reid, J; Wendt, M

    2012-01-01

    A superconducting RF accelerator test facility is being constructed at Fermilab. The existing New Muon Lab (NML) building is being converted for this facility. The accelerator will consist of an electron gun, injector, beam acceleration section consisting of 3 TTF-type or ILC-type cryomodules, multiple downstream beam lines for testing diagnostics and conducting various beam tests, and a high power beam dump. When completed, it is envisioned that this facility will initially be capable of gen...

  3. Step-Stress Accelerated Degradation Testing (SSADT) for Photovoltaic (PV) Devices and Cells (Presentation)

    Lee, J.; Elmore, R.; Suh, C.; Jones, W.

    2010-10-01

    Presentation on step-stress accelerated degradation testing (SSADT) for photovoltaics (PV). Developed are a step-stress degradation test (SSADT) for PV reliability tests and a lifetime prediction model for PV products.

  4. Status and plans for a SRF accelerator test faciliy at Fermilab

    Leibfritz, J; Carlson, K; Chase, B; Church, M; Harms, E; Klebaner, A; Kucera, M; Lackey, S; Martinez, A; Nagaitsev, S; Nobrega, L; Piot, P; Reid, J; Wendt, M; Wesseln, S

    2012-01-01

    A superconducting RF accelerator test facility is being constructed at Fermilab. The existing New Muon Lab (NML) building is being converted for this facility. The accelerator will consist of an electron gun, injector, beam acceleration section consisting of 3 TTF-type or ILC-type cryomodules, multiple downstream beam lines for testing diagnostics and conducting various beam tests, and a high power beam dump. When completed, it is envisioned that this facility will initially be capable of generating an 810 MeV electron beam with ILC beam intensity. Expansion plans of the facility are underway that will provide the capability to upgrade the accelerator to a total beam energy of 1.5 GeV. In addition to testing accelerator components, this facility will be used to test RF power equipment, instrumentation, LLRF and controls systems for future SRF accelerators such as the ILC and Project-X. This paper describes the current status and overall plans for this facility.

  5. Operational status of the Brookhaven National Laboratory Accelerator Test Facility

    Initial design parameters and early operational results of a 50 MeV high brightness electron linear accelerator are described. The system utilizes a radio frequency electron gun operating at a frequency of 2.856 GHz and a nominal output energy of 4.5 MeV followed by two, 2π/3 mode, disc loaded, traveling wave accelerating sections. The gun cathode is photo excited with short (6 psec) laser pulses giving design peak currents of a few hundred amperes. The system will be utilized to carry out infra-red FEL studies and investigation of new high gradient accelerating structures

  6. Optical system for measurement of pyrotechnic test accelerations

    Lieberman, Paul; Czajkowski, John; Rehard, John

    1992-12-01

    This effort was directed at comparing the response of several different accelerometer and amplifier combinations to the pyrotechnic pulse simulating the ordnance separation of stages of multistage missiles. These pyrotechnic events can contain peak accelerations in excess of 100,000 G and a frequency content exceeding 100,000 Hz. The main thrust of this work was to compare the several accelerometer systems with each other and with a very accurate laser Doppler displacement meter in order to establish the frequency bands and acceleration amplitudes where the accelerometer systems are in error. The comparisons were made in simple sine-wave and low-acceleration amplitude environments, as well as in very severe pyroshock environments. An optical laser Doppler displacement meter (LDDM) was used to obtain the displacement velocity and acceleration histories, as well as the corresponding shock spectrum.

  7. Acceleration test of heavy ion RFQ linac at TIT

    An 80 MHz heavy ion RFQ Linac at Tokyo Institute of Technology (TIT) was constructed for researches on inertial fusion and plasma experiments. The first acceleration was accomplished with low intensity He+ ion beam in 1993. This four vane type RFQ accelerates particles with charge to mass ratio (q/A) of 1/16 from 5 keV/amu to 214 keV/amu. Two-dimensional (2D) machining was applied for cutting of the RFQ vane-tips. The vane parameters for the RFQ were optimized considering the effects of multipole components at inter-vane field. In order to increase the acceleration efficiency synchronous phase was gradually raised from -30 degrees to -20 degrees at the open-quotes accelerator sectionclose quotes. The beam transmission is expected to be 68.4% for the beam current of 10 mA. Details of the RFQ tuning and performance will be reported

  8. Accelerated stability testing of organic photovoltaics using concentrated sunlight

    Katz, Eugene A.; Manor, Assaf; Mescheloff, Asaf;

    2012-01-01

    We suggest to use concentrated sunlight for accelerated studies of light-induced mechanisms in the degradation of organic photovoltaics (OPV) based on the polymer (P3HT)/fullerene (PCBM) bulk heterojunctions. Two particular cases of the degradation are reported.......We suggest to use concentrated sunlight for accelerated studies of light-induced mechanisms in the degradation of organic photovoltaics (OPV) based on the polymer (P3HT)/fullerene (PCBM) bulk heterojunctions. Two particular cases of the degradation are reported....

  9. Acceleration test of heavy ion RFQ linac at TIT

    An 80 MHz heavy ion RFQ linac at Tokyo Institute of Technology (TIT) has been constructed for research on inertial fusion and plasma experiments. Equipment for beam acceleration has been fabricated and assembled to confirm the performance with low currents of the RFQ. The linac successfully accelerated He+ and C2+ ion beams to their final energies of 219 keV/u. The obtained beam transmission was more than 89% with currents of a few tens μA. (orig.)

  10. Framework for a Comparative Accelerated Testing Standard for PV Modules: Preprint

    Kurtz, S.; Wohlgemuth, J.; Yamamichi, M.; Sample, T.; Miller, D.; Meakin, D.; Monokroussos, C.; TamizhMani, M.; Kempe, M.; Jordan, D.; Bosco, N.; Hacke, P.; Bermudez, V.; Kondo, M.

    2013-08-01

    As the photovoltaic industry has grown, the interest in comparative accelerated testing has also grown. Private test labs offer testing services that apply greater stress than the standard qualification tests as tools for differentiating products and for gaining increased confidence in long-term PV investments. While the value of a single international standard for comparative accelerated testing is widely acknowledged, the development of a consensus is difficult. This paper strives to identify a technical basis for a comparative standard.

  11. Lifetime Testing 700 MHz RF Windows for the Accelerator Production of Tritium Program

    Cummings, K.A.; Borrego, M. D.; DeBaca, J.; Harrison, J S; Rodriguez, M. B.; Roybal, D. M.; Roybal, W. T.; Ruggles, S. C.; Torrez, P. A.; White, G. D.

    2000-01-01

    Radio frequency (RF) windows are historically a point where failure occurs in input-power couplers for accelerators. To understand more about the reliability of high power RF windows, lifetime testing was done on 700 MHz coaxial RF windows for the Low Energy Demonstration Accelerator (LEDA) project of the Accelerator Production of Tritium (APT) program. The RF windows, made by Marconi Applied Technologies (formerly EEV), were tested at 800 kW for an extended period of time. Changes in the ref...

  12. STATISTICAL INFERENCE OF WEIBULL DISTRIBUTION FOR TAMPERED FAILURE RATE MODEL IN PROGRESSIVE STRESS ACCELERATED LIFE TESTING

    WANG Ronghua; FEI Heliang

    2004-01-01

    In this note, the tampered failure rate model is generalized from the step-stress accelerated life testing setting to the progressive stress accelerated life testing for the first time. For the parametric setting where the scale parameter satisfying the equation of the inverse power law is Weibull, maximum likelihood estimation is investigated.

  13. Development of laboratory acceleration test method for service life prediction of concrete structures

    Service life prediction of nuclear power plants depends on the application of history of structures, field inspection and test, the development of laboratory acceleration tests, their analysis method and predictive model. In this study, laboratory acceleration test method for service life prediction of concrete structures and application of experimental test results are introduced. This study is concerned with environmental condition of concrete structures and is to develop the acceleration test method for durability factors of concrete structures e.g. carbonation, sulfate attack, freeze-thaw cycles and shrinkage-expansion etc

  14. Integrated Vibration and Acceleration Testing to Reduce Payload Mass, Cost and Mission Risk Project

    National Aeronautics and Space Administration — We propose to develop a capability to provide integrated acceleration, vibration, and shock testing using a state-of-the-art centrifuge, allowing for the test of...

  15. Experimental test accelerator: description and results of initial experiments

    The ETA is a high current (10,000 Amp) linear induction accelerator that produces short (30 ns) pulses of electrons at 5 MeV twice per second or in bursts of 5 pulses separated by as little as one millisecond. At this time the machine has operated at 65% of its design current and 90% of the design voltage. This report contains a description of the accelerator and its diagnostics; the results of the initial year of operation; a comparison of design codes with experiments on beam transport; and a discussion of some of the special problems and their status

  16. Carbon ion and high intensity acceleration test of TIT heavy ion RFQ linac

    The RFQ Linac at Tokyo Institute of Technology (TIT-RFQ) was constructed and acceleration test of ion beams 4He+ and 12C2+ was performed. The linac was designed to accelerate particles with charge to mass ratio(q/A) of 1-1/16 injected at 5 keV/u up to 214 keV/u. As the result of acceleration test, beam transmission was 89% for a low beam current. It is nearly design data 91% and the acceleration characteristic agrees well with a computer simulation. (author)

  17. Life Prediction of DC Motor using Time Series Analysis based on Accelerated Degradation Testing

    Li Wang

    2013-12-01

    Full Text Available This study presents a method of life prediction for DC motor using time series modeling procedure based on DC motor accelerated degradation testing data. DC motor accelerated degradation data are treated as time series and stochastic process are utilized to describe the degradation process for life prediction. An accelerated degradation test is processed for DC motor until they failed and the accelerated degradation data are collected for life prediction. A comparison between the predicted lifetime and the real lifetime of DC motors is processed and the results show that the life prediction of DC motors using time series analysis is effective.

  18. Estimation in Step-Stress Accelerated Life Tests for Power Generalized Weibull Distribution with Progressive Censoring

    M. M. Mohie EL-Din

    2015-01-01

    Full Text Available Based on progressive censoring, step-stress partially accelerated life tests are considered when the lifetime of a product follows power generalized Weibull distribution. The maximum likelihood estimates (MLEs and Bayes estimates (BEs are obtained for the distribution parameters and the acceleration factor. In addition, the approximate and bootstrap confidence intervals (CIs of the estimators are presented. Furthermore, the optimal stress change time for the step-stress partially accelerated life test is determined by minimizing the asymptotic variance of MLEs of the model parameters and the acceleration factor. Simulation results are carried out to study the precision of the MLEs and BEs for the parameters involved.

  19. Accelerated high-temperature creep tests for assessment of service life of power engineering steels

    Principles of accelerated constant stress - variable temperature and constant temperature - variable stress creep tests are discussed. Numerous accelerated creep tests of low-alloy Cr-Mo and Cr-Mo-V steels and high-alloy ferritic 12Cr1Mo-V steel carried out at higher-than-service temperatures and constant further service stress produced results which were in satisfactory agreement with conventional long-term creep tests. Such accelerated tests are used for practical purposes including estimation of service life, residual life and available residual life. On the other hand accelerated creep rupture tests carried out at constant service temperatures and variable stress trend to overestimate service life, create danger of unexpected failures of components under consideration and are seldom used for practical purposes. At comparable temperatures and stress levels accelerated creep tests using miniature test pieces tend to produce shorter rupture times than tests using standard specimens. The estimated life therefore shorter than that estimated on the basis of long-term tests and standard specimens. Service life estimated by means of accelerated creep tests using miniature test pieces must be calculated with the use of a corrective factor selected individually for the given type of steel. (author)

  20. Optical diagnostics in the advanced test accelerator (ATA) environment

    The ATA is a 50-MeV, 10-kA, 70-ns pulsed electron beam accelerator that generates an extremely harsh environment for diagnostic measurements. Diagnostic targets placed in the beamline are subject to damage, frequently being destroyed by a single pulse. High radiation (x-ray, gamma, and neutron) and electromagnetic interference levels preclude placing components near the beamline that are susceptible to radiation damage. Examples of such components are integrated circuit elements, hydrocarbons such as Teflon insulation, and optical components that darken, resulting in transmission loss. Optical diagnostics play an important part in measuring experimental parameters such as the beam current density profile. A large number of optical lines of sight (LOS) are routinely deployed along the experimental beamlines that use the ATA beam. Gated TV cameras are located outside the accelerator tunnel, because the tunnel is inaccessible during operations. We will describe and discuss the difficulties, problems, and solutions encountered in making optical measurements in the ATA environment

  1. Design and Simulation of IOTA - a Novel Concept of Integrable Optics Test Accelerator

    Nagaitsev, S.; Valishev, A.; Danilov, V. V.; Shatilov, D. N.

    2013-01-01

    The use of nonlinear lattices with large betatron tune spreads can increase instability and space charge thresholds due to improved Landau damping. Unfortunately, the majority of nonlinear accelerator lattices turn out to be nonintegrable, producing chaotic motion and a complex network of stable and unstable resonances. Recent advances in finding the integrable nonlinear accelerator lattices have led to a proposal to construct at Fermilab a test accelerator with strong nonlinear focusing whic...

  2. Accelerated electrochemical test of 14Kh17N2 steel susceptibility to ICC

    Description of the accelerated electrochemical technique used to determine susceptibility 14Kh17N2 steel of ferrite-martensite type to intercrystallite corrosion under the drop of electrolyte, is given. Convergence of the results obtained due to accelerated techniques with those of tests using the All-Union Standards 6032-84 constitutes 95%. These results demonstrate possibility to use data of the accelerated techniques for rapid estimation of susceptibility to ICC of martensite-ferrite steel-14Kh17N2

  3. WAN environment test for joint development of accelerator control programs

    By the heightening of the processing capability of personal computers, also in the field of accelerator control, the system using personal computers as the main body can be constructed. Also it has become possible to supplement functions by combining different applications and offering the means of communication between applications by operating systems. At present, new accelerators are planned in Laboratory of Nuclear Science, Tohoku University, and National Laboratory for High Energy Physics, and the development environment using WAN was prepared for the purposes of the OMT analysis of accelerator domain from the viewpoint of control, the joint verification of the programs being made, and the efficient exchange of information. Windows NT was adopted, and its features are shown. The environment was constructed by using the personal computer on which Windows NT functions, and the specification of the used personal computer is shown. The performance was measured by using this environment, and its method and the results are reported. The operation mode for hereafter is explained. The construction of the development environment using Windows NT was completed with good results. (K.I.)

  4. Design, fabrication and first beam tests of the C-band RF acceleration unit at SINAP

    Fang, Wencheng; Gu, Qiang; Sheng, Xing; Wang, Chaopeng; Tong, Dechun; Chen, Lifang; Zhong, Shaopeng; Tan, Jianhao; Lin, Guoqiang; Chen, Zhihao; Zhao, Zhentang

    2016-07-01

    C-band RF acceleration is a crucial technology for the compact Free Electron Laser (FEL) facility at the Shanghai Institute of Applied Physics (SINAP), Chinese Academy of Sciences. A project focusing on C-band RF acceleration technology was launched in 2008, based on high-gradient accelerating structures powered by klystron and pulse compressor units. The target accelerating gradient is 40 MV/m or higher. Recently one prototype of C-band RF unit, consisting of a 1.8 m accelerating structure and a klystron with a TE0115 mode pulse compressor, has been tested with high-power and electron beam. Stable operation at 40 MV/m was demonstrated and, 50 MV/m approached by the end of the test. This paper introduces the C-band R&D program at SINAP and presents the experiment results of high-power and beam tests.

  5. Lifetime Testing 700 MHz RF Windows for the Accelerator Production of Tritium Program

    Cummings, K A; De Baca, J; Harrison, J S; Rodríguez, M B; Roybal, D M; Roybal, W T; Ruggles, S C; Torrez, P A; White, G D

    2000-01-01

    Radio frequency (RF) windows are historically a point where failure occurs in input-power couplers for accelerators. To understand more about the reliability of high power RF windows, lifetime testing was done on 700 MHz coaxial RF windows for the Low Energy Demonstration Accelerator (LEDA) project of the Accelerator Production of Tritium (APT) program. The RF windows, made by Marconi Applied Technologies (formerly EEV), were tested at 800 kW for an extended period of time. Changes in the reflected power, vacuum, air outlet temperature, and surface temperature were monitored over time. The results of the life testing are summarized.

  6. History of Accelerated and Qualification Testing of Terrestrial Photovoltaic Modules: A Literature Review

    Osterwald, C. R.; McMahon, T. J.

    2009-01-01

    We review published literature from 1975 to the present for accelerated stress testing of flat-plate terrestrial photovoltaic (PV) modules. An important facet of this subject is the standard module test sequences that have been adopted by national and international standards organizations, especially those of the International Electrotechnical Commission (IEC). The intent and history of these qualification tests, provided in this review, shows that standard module qualification test results cannot be used to obtain or infer a product lifetime. Closely related subjects also discussed include: other limitations of qualification testing, definitions of module lifetime, module product certification, and accelerated life testing.

  7. Analysis of Transmitted Optical Spectrum Enabling Accelerated Testing of CPV Designs: Preprint

    Miller, D. C.; Kempe, M. D.; Kennedy, C. E.; Kurtz, S. R.

    2009-07-01

    Reliability of CPV systems' materials is not well known; methods for accelerated UV testing have not been developed. UV and IR spectra transmitted through representative optical systems are evaluated.

  8. Measuring test mass acceleration noise in space-based gravitational wave astronomy

    Congedo, Giuseppe

    2014-01-01

    The basic constituent of interferometric gravitational wave detectors -- the test mass to test mass interferometric link -- behaves as a differential dynamometer measuring effective differential forces, comprising an integrated measure of gravity curvature, inertial effects, as well as non-gravitational spurious forces. This last contribution is going to be characterised by the LISA Pathfinder mission, a technology precursor of future space-borne detectors like eLISA. Changing the perspective from displacement to acceleration can benefit the data analysis of LISA Pathfinder and future detectors. The response in differential acceleration to gravitational waves is derived for a space-based detector's interferometric link. The acceleration formalism can also be integrated into time delay interferometry by building up the unequal-arm Michelson differential acceleration combination. The differential acceleration is nominally insensitive to the system free evolution dominating the slow displacement dynamics of low-...

  9. CERN Technical training 2008 - Learning for the LHC: Special Workshop demonstrating reliability with accelerated testing

    2008-01-01

    Larry Edson’s workshop will show examples of quantitative reliability predictions based upon accelerated testing and demonstrate that reliability testing during the prototyping phase will help ascertain product shortcomings. When these weak points are addressed and the redesigned product is re-tested, the reliability of that product will become much higher. These methodologies successfully used in industry might be exceedingly useful also for component development in particle physics where reliability is of the utmost importance. This training will provide participants with the skills necessary to demonstrate reliability requirements using accelerated testing methods. The workshop will focus on accelerated test design that employs increased stress levels. This approach has the advantage of reducing test time, sample size and test facility resources. The methodologies taught are applicable to all types of stresses, spanning the elec...

  10. CERN Technical training 2008 - Learning for the LHC: Special Workshop demonstrating reliability with accelerated testing

    2008-01-01

    Larry Edson’s workshop will show examples of quantitative reliability predictions based upon accelerated testing and demonstrates that reliability testing during the prototyping phase will help ascertain product shortcomings. When these weak points are addressed and the redesigned product is re-tested, the reliability of that product will become much higher. These methodologies successfully used in industry might be exceedingly useful also for component development in particle physics where reliability is of utmost importance. This training will provide participants with the skills necessary to demonstrate reliability requirements using accelerated testing methods. The workshop will focus on accelerated test design that employs increased stress levels. This approach has the advantage of reducing test time, sample size and test facility resources. The methodologies taught are applicable to all types of stresses, spanning the electro...

  11. CERN Technical training 2008 - Learning for the LHC: Special workshop demonstrating reliability with accelerated testing

    2008-01-01

    Larry Edson’s workshop will show examples of quantitative reliability predictions based upon accelerated testing and demonstrate that reliability testing during the prototyping phase will help ascertain product shortcomings. When these weak points are addressed and the redesigned product is re-tested, the reliability of that product will become much higher. These methodologies successfully used in industry might be exceedingly useful also for component development in particle physics where reliability is of the utmost importance. This training will provide participants with the skills necessary to demonstrate reliability requirements using accelerated testing methods. The workshop will focus on accelerated test design that employs increased stress levels. This approach has the advantage of reducing test time, sample size and test facility resources. The methodologies taught are applicable to all types of stresses, spanning the elec...

  12. Development of an accelerated reliability test schedule for terrestrial solar cells

    Lathrop, J. W.; Prince, J. L.

    1981-01-01

    An accelerated test schedule using a minimum amount of tests and a minimum number of cells has been developed on the basis of stress test results obtained from more than 1500 cells of seven different cell types. The proposed tests, which include bias-temperature, bias-temperature-humidity, power cycle, thermal cycle, and thermal shock tests, use as little as 10 and up to 25 cells, depending on the test type.

  13. The Use of Conditional Probability Integral Transformation Method for Testing Accelerated Failure Time Models

    Abdalla Ahmed Abdel-Ghaly; Hanan Mohamed Aly; Elham Abdel-Malik Abde-Rahman

    2016-01-01

    This paper suggests the use of the conditional probability integral transformation (CPIT) method as a goodness of fit (GOF) technique in the field of accelerated life testing (ALT), specifically for validating the underlying distributional assumption in accelerated failure time (AFT) model. The method is based on transforming the data into independent and identically distributed (i.i.d) Uniform (0, 1) random variables and then applying the modified Watson statistic to test the uniformity of t...

  14. Evaluation of accelerated deterioration in NAPTF flexible test pavements

    Kasthurirangan GOPALAKRISHNAN

    2008-01-01

    Previous research studies have successfully demonstrated the use of artificial neural network(ANN)models for predicting critical structural responses and layer moduli of highway flexible pavements.The primary objective of this study was to develop an ANN-based approach for backcalculation of pavement moduli based on heavy weight deflectometer(HWD)test data,especially in the analysis of airport flexible pavements subjected to new generation aircraft(NGA).Two medium-strength subgrade flexible test sections,at the National Airport Pavement Test Facility(NAPTF),were modeled using a finite element(FE) based pavement analysis program,which can consider the non-linear stress-dependent behavior of pavement geomaterials.A multi-layer,feed-forward network which uses an error-backpropagation algorithm was trained to approximate the HWD backcalculation function using the FE program generated synthetic database.At the NAPTF,test sections were subjected to Boeing 777 (B777)trafficking on one lane and Boeing 747(B747)trafficking on the other lane using a test machine.To monitor the effect of traffic and climatic variations on pavement structural responses.HWD tests were conducted on the traffieked lanes and on the untraffieked centerline of test sections as trafficking progressed.The trained ANN models were successfully applied on the actual HWD test data acquired at the NAPTF to predict the asphalt concrete moduli and non-1inear subgrade moduli of the medium-strength subgrade flexible test sections.

  15. Cold test results of a side-coupled standing-wave electron-accelerating structure

    Song, Ki Baek; Li, Yonggui; Lee, Sanghyun; Lee, Byeong-No; Park, Hyung Dal; Cha, Sung-Su; Lee, Byung Cheol

    2013-07-01

    The radio-frequency (RF) cavity for the dual-energy S-band electron linear accelerator (LINAC) is designed for a cargo inspection system (CIS) at the Korea Atomic Energy Research Institute (KAERI). The cold test results of the electron accelerator structure, which has a side-coupled standing-wave interlaced-pulse dual-energy mode, are described. The design concept, basic structure, microwave-tuning method, and cold-test procedure are described as well. The measured dispersion curve, spectrum characteristics, ρ-f relation of the power coupler, and axial field distribution of the accelerating gradient are provided.

  16. Status and Plans for a Superconducting RF Accelerator Test Facility at Fermilab

    The Advanced Superconducting Test Accelerator (ASTA) is being constructed at Fermilab. The existing New Muon Lab (NML) building is being converted for this facility. The accelerator will consist of an electron gun, injector, beam acceleration section consisting of 3 TTF-type or ILC-type cryomodules, multiple downstream beam lines for testing diagnostics and conducting various beam tests, and a high power beam dump. When completed, it is envisioned that this facility will initially be capable of generating a 750 MeV electron beam with ILC beam intensity. An expansion of this facility was recently completed that will provide the capability to upgrade the accelerator to a total beam energy of 1.5 GeV. Two new buildings were also constructed adjacent to the ASTA facility to house a new cryogenic plant and multiple superconducting RF (SRF) cryomodule test stands. In addition to testing accelerator components, this facility will be used to test RF power systems, instrumentation, and control systems for future SRF accelerators such as the ILC and Project-X. This paper describes the current status and overall plans for this facility.

  17. Testing of a Loop Heat Pipe Subjective to Variable Accelerations. Part 1; Start-up

    Ku, Jentung; Rogers, Paul; Hoff, Craig

    2000-01-01

    The effect of accelerating forces on the performance of loop heat pipes (LHP) is of interest and importance to terrestrial and space applications. They are being considered for cooling of military combat vehicles and for spinning spacecraft. In order to investigate the effect of an accelerating force on LHP operation, a miniature LHP was installed on a spin table. Variable accelerating forces were imposed on the LHP by spinning the table at different angular speeds. Several patterns of accelerating forces were applied, i.e. continuous spin at different speeds and periodic spin at different speeds and frequencies. The resulting accelerations ranged from 1.17 g's to 4.7 g's. This paper presents the first part of the experimental study, i.e. the effects of a centrifugal force on the LHP start-up. Tests were conducted by varying the heat load to the evaporator, sink temperature, magnitude and frequency of centrifugal force, and LHP orientation relative to the direction of the accelerating force. The accelerating force seems to have little effect on the loop start-up in terms of temperature overshoot and superheat at boiling incipience. Changes in these parameters seem to be stochastic with or without centrifugal accelerating forces. The LHP started successfully in all tests.

  18. Status and Plans for an SRF Accelerator Test Facility at Fermilab

    Church, M; Nagaitsev, S

    2012-01-01

    A superconducting RF accelerator test facility is currently under construction at Fermilab. The accelerator will consist of an electron gun, 40 MeV injector, beam acceleration section consisting of 3 TTF-type or ILC-type cryomodules, and multiple downstream beam lines for testing diagnostics and performing beam experiments. With 3 cryomodules installed this facility will initially be capable of generating an 810 MeV electron beam with ILC beam intensity. The facility can accommodate up to 6 cryomodules for a total beam energy of 1.5 GeV. This facility will be used to test SRF cryomodules under high intensity beam conditions, RF power equipment, instrumentation, and LLRF and controls systems for future SRF accelerators such as the ILC and Project-X. This paper describes the current status and overall plans for this facility.

  19. Status and Plans for an SRF Accelerator Test Facility at Fermilab

    Church, M.; Leibfritz, J.; Nagaitsev, S.; /Fermilab

    2011-07-29

    A superconducting RF accelerator test facility is currently under construction at Fermilab. The accelerator will consist of an electron gun, 40 MeV injector, beam acceleration section consisting of 3 TTF-type or ILC-type cryomodules, and multiple downstream beam lines for testing diagnostics and performing beam experiments. With 3 cryomodules installed this facility will initially be capable of generating an 810 MeV electron beam with ILC beam intensity. The facility can accommodate up to 6 cryomodules for a total beam energy of 1.5 GeV. This facility will be used to test SRF cryomodules under high intensity beam conditions, RF power equipment, instrumentation, and LLRF and controls systems for future SRF accelerators such as the ILC and Project-X. This paper describes the current status and overall plans for this facility.

  20. Experimental evaluation of the Battelle accelerated test design for the solar array at Mead, Nebraska

    Frickland, P.O.; Repar, J.

    1982-04-06

    A previously developed test design for accelerated aging of photovoltaic modules was experimentally evaluated. The studies included a review of relevant field experience, environmental chamber cycling of full-size modules, and electrical and physical evaluation of the effects of accelerated aging during and after the tests. The test results indicated that thermally induced fatigue of the interconnects was the primary mode of module failure as measured by normalized power output. No chemical change in the silicone encapsulant was detectable after 360 test cycles.

  1. On selection of optimal stochastic model for accelerated life testing

    This paper deals with the problem of proper lifetime model selection in the context of statistical reliability analysis. Namely, we consider regression models describing the dependence of failure intensities on a covariate, for instance, a stressor. Testing the model fit is standardly based on the so-called martingale residuals. Their analysis has already been studied by many authors. Nevertheless, the Bayes approach to the problem, in spite of its advantages, is just developing. We shall present the Bayes procedure of estimation in several semi-parametric regression models of failure intensity. Then, our main concern is the Bayes construction of residual processes and goodness-of-fit tests based on them. The method is illustrated with both artificial and real-data examples. - Highlights: • Statistical survival and reliability analysis and Bayes approach. • Bayes semi-parametric regression modeling in Cox's and AFT models. • Bayes version of martingale residuals and goodness-of-fit test

  2. Novel accelerated corrosion test for LY12CZ and LC4CS aluminum alloys

    CAI Jian-ping; LIU Ming

    2006-01-01

    A new accelerated corrosion test-comprehensive environmental test (CET) was developed in order to estimate the outdoor corrosion of aluminum alloys in marine environment. The environmental characteristics in CET were studied by atmospheric corrosion monitor (ACM), and the morphology of corrosion product was observed by SEM. The correlation between the accelerated corrosion tests and outdoor exposure was discussed. The results show that the anti-corrosion ranking for LY12CZ, LC4CS, clad LY12CZ, and clad LC4CS in CET is the same as that of the alloys exposed outdoor, and ACM study shows that CET demonstrates the same environmental characteristics as that exposed outdoor. CET is a more accurate accelerated corrosion test, and a mathematical relation was obtained to describe the relation between CET and outdoor test.

  3. Accelerated fatigue testing of LM 19.1 blades

    Kristensen, Ole Jesper Dahl; Jørgensen, E.

    2003-01-01

    material. In addition to the thermal imaging surveillance the blades were instrumented with strain gauges. This report presents the temperature duringtest, calibration test results, moment range measurements, strain statistics, thermal imaging registrations and a determination of the size and cause of the...

  4. Poisson simulation for high voltage terminal of test stand for 1MV electrostatic accelerator

    KOMAC provide ion beam to user which energy range need to expand to MeV range and develop 1 MV electrostatic accelerator. The specifications of the electrostatic accelerator are 1MV acceleration voltage, 10 mA peak current and variable gas ion. We are developing test stand before set up 1 MV electrostatic accelerator. The test stand voltage is 300 kV and operating time is 8 hours. The test stand is consist of 300 kV high voltage terminal, DC-AC-DC inverter, power supply device inside terminal, 200MHz RF power, 5 kV extraction power supply, 300 kV accelerating tube and vacuum system.. The beam measurement system and beam dump will be installed next to accelerating tube. Poisson code simulation results of the high voltage terminal are presented in this paper. Poisson code has been used to calculate the electric field for high voltage terminal. The results of simulation were verified with reasonable results. The poisson code structure could be apply to the high voltage terminal of the test stand

  5. Enabling More than Moore: Accelerated Reliability Testing and Risk Analysis for Advanced Electronics Packaging

    Ghaffarian, Reza; Evans, John W.

    2014-01-01

    For five decades, the semiconductor industry has distinguished itself by the rapid pace of improvement in miniaturization of electronics products-Moore's Law. Now, scaling hits a brick wall, a paradigm shift. The industry roadmaps recognized the scaling limitation and project that packaging technologies will meet further miniaturization needs or ak.a "More than Moore". This paper presents packaging technology trends and accelerated reliability testing methods currently being practiced. Then, it presents industry status on key advanced electronic packages, factors affecting accelerated solder joint reliability of area array packages, and IPC/JEDEC/Mil specifications for characterizations of assemblies under accelerated thermal and mechanical loading. Finally, it presents an examples demonstrating how Accelerated Testing and Analysis have been effectively employed in the development of complex spacecraft thereby reducing risk. Quantitative assessments necessarily involve the mathematics of probability and statistics. In addition, accelerated tests need to be designed which consider the desired risk posture and schedule for particular project. Such assessments relieve risks without imposing additional costs. and constraints that are not value added for a particular mission. Furthermore, in the course of development of complex systems, variances and defects will inevitably present themselves and require a decision concerning their disposition, necessitating quantitative assessments. In summary, this paper presents a comprehensive view point, from technology to systems, including the benefits and impact of accelerated testing in offsetting risk.

  6. Life Prediction on a T700 Carbon Fiber Reinforced Cylinder with Limited Accelerated Life Testing Data

    Ma Xiaobing

    2015-01-01

    Full Text Available An accelerated life testing investigation was conducted on a composite cylinder that consists of aluminum alloy and T700 carbon fiber. The ultimate failure stress predictions of cylinders were obtained by the mixing rule and verified by the blasting static pressure method. Based on the stress prediction of cylinder under working conditions, the constant stress accelerated life test of the cylinder was designed. However, the failure data cannot be sufficiently obtained by the accelerated life test due to the time limitation. Therefore, most of the data presented to be high censored in high stress level and zero-failure data in low stress level. When using the traditional method for rupture life prediction, the results showed to be of lower confidence. In this study, the consistency of failure mechanism for carbon fiber and cylinder was analyzed firstly. According to the analysis result, the statistical test information of carbon fiber could be utilized for the accelerated model constitution. Then, rupture life prediction method for cylinder was proposed based on the accelerated life test data and carbon fiber test data. In this way, the life prediction accuracy of cylinder could be improved obviously, and the results showed that the accuracy of this method increased by 35%.

  7. Development of an accelerated test for Internal Sulfate Attack study

    Khelil Nacim; Aubert Jean-Emmanuel; Escadeillas Gilles

    2014-01-01

    Internal Sulfate Attack (ISA) is a pathology that occurs under certain conditions in concrete having undergone heating above 70 °C at early age (through heating in pre-casting industry or due to hydration in large concrete parts). This reaction deemed very slow, numerous methods to speed up reactions leading to delayed ettringite formation have been developed. These methods are all based on the material damage. Another type of test is currently under development. It is based on rehabilitation...

  8. Design and Factory Test of the e+/e- Frascati Linear Accelerator for DAFNE

    The electron-positron accelerator for the DAFNE project has been built and is in test at Titan Beta in Dublin, CA. This S-Band RF linac system utilizes four 45 MW sledded klystrons and 16-3 m accelerating structures to achieve the required performance. It delivers a 4 ampere electron beam to the positron converter and accelerates the resulting positrons to 550 MeV. The converter design uses a 4.3T pulsed tapered flux compressor along with a pseudo-adiabatic tapered field to a 5 KG solenoid over the first two positron accelerating sections. Quadrupole focusing is used after 100 MeV. The system performance is given in Table 1. This paper briefly describes the design and development of the various subassemblies in this system and gives the initial factory test data.

  9. Isolation of a piezoresistive accelerometer used in high acceleration tests

    Bateman, V. I.; Brown, F. A.; Davie, N. T.

    Both uniaxial and triaxial shock isolation techniques for a piezoresistive accelerometer have been developed for pyroshock and impact tests. The uniaxial shock isolation technique has demonstrated acceptable characteristics for a temperature range of -50 to +186 F and a frequency bandwidth of DC to 10 kHz. The triaxial shock isolation technique has demonstrated acceptable results for a temperature range of -50 to 70 F and a frequency bandwidth of DC to 10 kHz. These temperature ranges, that are beyond the accelerometer manufacturer's operational limits of -30 and +150 F, required the calibration of accelerometers at high shock levels and at the temperature extremes of -50 and +160 F. The purposes of these calibrations were to insure that the accelerometers operated at the field test temperatures and to provide an accelerometer sensitivity at each test temperature. Since there is no NIST-traceable (National Institute of Standards and Technology traceable) calibration capability at shock levels of 5,000 - 15,000 g for the temperature extremes of -50 and +160 F, a method for calibrating and certifying the Hopkinson bar with a transfer standard was developed. Time domain and frequency domain results are given that characterize the Hopkinson bar. The NIST-traceable accuracy for the standard accelerometer in shock is +\\-5%. The Hopkinson bar has been certified by the Sandia Secondary Standards Division with an uncertainty of 6%.

  10. Test Ion Acceleration in the Field of Expanding Planar Electron Cloud

    Basko, M. M.

    2006-01-01

    New exact results are obtained for relativistic acceleration of test positive ions in the non-Boltzmann laminar zone of a planar electron sheath evolving from an initially mono-energetic electron distribution. The electron dynamics is analyzed against the background of motionless foil ions. The limiting gamma-factor of accelerated ions is shown to be determined primarily by the values of the ion-electron charge-over-mass ratio and the initial gamma-factor of the accelerated electrons: there e...

  11. On the application of design of experiments to accelerated life testing

    Today, there is an increasing demand for improved quality and reliability due to increasing system complexity and increasing demands from customer. Continuous improvement of quality is not only a means of competition but also a matter of staying in the market. Accelerated life testing and statistical design of experiments are two needed methods for improvement of quality. The combined use of them is very advantageous and increases the test efficiency. Accelerated life testing is a quick way to provide information on the life distribution of materials and products. By subjecting the test unit to conditions more severe than those at normal usage, the test time can be highly reduced. Estimates of life at normal stress levels are obtained by extrapolating the available information through a reasonable acceleration model. Accelerated life testing has mostly been used to measure reliability but it is high time to use it for improvement of quality. Design of experiments serves to find out the effect of design parameters and other interesting factors on performance measure and its variability. The obtained information is essential for a continuous improvement of quality. As an illustration, two sets of experiment are designed and performed at highly increased stress levels. The results are analysed and discussed and a time saving alternative is proposed. The combination of experimental design and accelerated life testing is discussed and illustrated. The combined use of these methods can be argued for in two different cases. One is for an exploratory improvement investigation and the other is for verification of reliability. In either case, the combined use is advantageous and improves the testing efficiency. Some general conclusions are drawn to be used for planning and performance of statistically designed accelerated life testing experiments. (70 refs.) (au)

  12. A Proposed Experimental Test of Proton-Driven Plasma Wakefield Acceleration Based on CERN SPS

    Xia, G X; Lotov, K; Pukhov, A; Assmann, R; Zimmermann, F; Huang, C; Vieira, J; Lopes, N; Fonseca, RA; Silva, LO; An, W; Joshi, C; Mori, W; Lu, W; Muggli, P

    2011-01-01

    Proton-bunch driven plasma wakefield acceleration (PDPWA) has been proposed as an approach to accelerate electron beam to TeV energy regime in a single plasma section. An experimental test has recently proposed to demonstrate the capability of PDPWA by using proton beams from the CERN SPS. The layout of the experiment is introduced. Particle-in-cell simulation results based on the realistic beam parameters are presented. Presented at PAC2011 New York, 28 March - 1 April 2011.

  13. Electron lenses and cooling for the Fermilab Integrable Optics Test Accelerator

    Stancari, G; Burov, A.; Lebedev, V.; Nagaitsev, S.; Prebys, E.; Valishev, A.

    2015-01-01

    Recently, the study of integrable Hamiltonian systems has led to nonlinear accelerator lattices with one or two transverse invariants and wide stable tune spreads. These lattices may drastically improve the performance of high-intensity machines, providing Landau damping to protect the beam from instabilities, while preserving dynamic aperture. The Integrable Optics Test Accelerator (IOTA) is being built at Fermilab to study these concepts with 150-MeV pencil electron beams (single-particle d...

  14. Constant-stress partially accelerated life tests for inverted Weibull distribution with multiple censored data

    Amal S. Hassan

    2015-04-01

    Full Text Available Testing the lifetime of items under normal use condition often requires a long period of time, especially for products having high reliability. To minimize the costs involved in testing without reducing the quality of the data obtained, the items run at higher than usual level of stresses to induce early failures in a short time. This article concerns with constant–stress partially accelerated life test with multiple censored data. The life time of test item is assumed to follow inverted Weibull distribution. Maximum likelihood estimates are obtained for the model parameters and acceleration factor. In addition, asymptotic variance and covariance matrix of the estimators is given. The confidence intervals of the unknown parameters and acceleration factor are constructed for large sample sizes. Simulation studies are performed to investigate the performance of the estimators.

  15. A Study on the Storage Reliability of LSINS Based on Step-stress Accelerated Life Test

    Teng Fei

    2015-01-01

    Full Text Available Based on the step-stress accelerated life test and the laser strap-down inertial navigation system, this paper studies the accelerated life model and the test method, provides the likelihood function, the likelihood equation and the two-order derivative when the stress level is k, evaluates the effectiveness of the method with the simulation test model established by MATLAB, applies the research findings in the storage reliability study of the XX laser strap-down inertial navigation system, and puts forward an effective evaluation method of the storage life of the inertial navigation system.

  16. Isolation of a piezoresistive accelerometer used in high acceleration tests

    Bateman, V.I.; Brown, F.A.; Davie, N.T.

    1992-12-31

    Both uniaxial and triaxial shock isolation techniques for a piezoresistive accelerometer have been developed for pyroshock and impact tests. The uniaxial shock isolation technique has demonstrated acceptable characteristics for a temperature range of {minus}50{degree}F to +186{degree}F and a frequency bandwidth of DC to 10 kHz. The triaxial shock isolation technique has demonstrated acceptable results for a temperature range of {minus}50{degree}F to 70{degree}F and a frequency bandwidth of DC to 10 kHz. These temperature ranges, that are beyond the accelerometer manufacturer`s operational limits of {minus}30{degree}F and +150{degree}F, required the calibration of accelerometers at high shock levels and at the temperature extremes of {minus}50{degree}F and +160{degree}F. The purposes of these calibrations were to insure that the accelerometers operated at the field test temperatures and to provide an accelerometer sensitivity at each test temperature. Since there is no NIST-traceable (National Institute of Standards and Technology traceable) calibration capability at shock levels of 5,000 g - 15,000 g for the temperature extremes of {minus}50{degree}F and +160{degree}F, a method for calibrating and certifying the Hopkinson bar with a transfer standard was developed. Time domain and frequency domain results are given that characterize the Hopkinson bar. The NIST-traceable accuracy for the standard accelerometer in shock is {plus_minus}5%. The Hopkinson bar has been certified by the Sandia Secondary Standards Division with an uncertainty of 6%.

  17. Constant-stress partially accelerated life tests for inverted Weibull distribution with multiple censored data

    Amal S. Hassan; Salwa M. Assar; Ahmed N. Zaky

    2015-01-01

    Testing the lifetime of items under normal use condition often requires a long period of time, especially for products having high reliability. To minimize the costs involved in testing without reducing the quality of the data obtained, the items run at higher than usual level of stresses to induce early failures in a short time. This article concerns with constant–stress partially accelerated life test with multiple censored data. The life time of test item is assumed to follow inverted Weib...

  18. Accelerated testing of solid oxide fuel cell stacks for micro combined heat and power application

    Hagen, Anke; Høgh, Jens Valdemar Thorvald; Barfod, Rasmus

    2015-01-01

    State-of-the-art (SoA) solid oxide fuel cell (SOFC) stacks are tested using profiles relevant for use in micro combined heat and power (CHP) units. Such applications are characterised by dynamic load profiles. In order to shorten the needed testing time and to investigate potential acceleration of...

  19. Kerr black holes as accelerators of spinning test particles

    Guo, Minyong; Gao, Sijie

    2016-04-01

    It has been shown that ultraenergetic collisions can occur near the horizon of an extremal Kerr black hole. Previous studies mainly focused on geodesic motions of particles. In this paper, we consider spinning test particles whose orbits are nongeodesic. By employing the Mathisson-Papapetrou-Dixon equation, we find the critical angular momentum satisfies J =2 E for extremal Kerr black holes. Although the conserved angular momentum J and energy E have been redefined in the presence of spin, the critical condition remains the same form. If a particle with this angular momentum collides with another particle arbitrarily close to the horizon of the black hole, the center-of-mass energy can be arbitrarily high. We also prove that arbitrarily high energies cannot be obtained for spinning particles near the horizons of nonextremal Kerr black holes.

  20. Kerr black holes as accelerators of spinning test particles

    Guo, Minyong

    2016-01-01

    It has been shown that ultraenergetic collisions can occur near the horizon of an extremal Kerr black hole. Previous studies mainly focused on geodesic motions of particles. In this paper, we consider spinning test particles whose orbits are non-geodesic. By employing the Mathisson-Papapetrou-Dixon equation, we find the critical angular momentum satisfies $J=2E$ for extremal Kerr black holes. Although the conserved angular momentum $J$ and energy $E$ have been redefined in the presence of spin, the critical condition remains the same form. If a particle with this angular momentum collides with another particle arbitrarily close to the horizon of the black hole, the center-of-mass energy can be arbitrarily high. We also prove that arbitrarily high energies cannot be obtained for spinning particles near the horizons of non-extremal Kerr black holes.

  1. Life prediction of OLED for constant-stress accelerated degradation tests using luminance decaying model

    In order to acquire the life information of organic light emitting diode (OLED), three groups of constant stress accelerated degradation tests are performed to obtain the luminance decaying data of samples under the condition that the luminance and the current are respectively selected as the indicator of performance degradation and the test stress. Weibull function is applied to describe the relationship between luminance decaying and time, least square method (LSM) is employed to calculate the shape parameter and scale parameter, and the life prediction of OLED is achieved. The numerical results indicate that the accelerated degradation test and the luminance decaying model reveal the luminance decaying law of OLED. The luminance decaying formula fits the test data very well, and the average error of fitting value compared with the test data is small. Furthermore, the accuracy of the OLED life predicted by luminance decaying model is high, which enable rapid estimation of OLED life and provide significant guidelines to help engineers make decisions in design and manufacturing strategy from the aspect of reliability life. - Highlights: • We gain luminance decaying data by accelerated degradation tests on OLED. • The luminance decaying model objectively reveals the decaying law of OLED luminance. • The least square method (LSM) is employed to calculate Weibull parameters. • The plan designed for accelerated degradation tests proves to be feasible. • The accuracy of the OLED life and the luminance decaying fitting formula is high

  2. X-band klystron modulator for the Accelerator Test Facility

    An X-band Klystron Modulator has been designed and constructed to drive two kinds of prototype X-band pulsed klystrons: (1) 30 MW klystron ( XB-50K) requiring a 450 kV beam voltage with a 0.5 μs flat top and (2) 120 MW klystron ( XB-72K) requiring a 550 kV beam voltage with a 0.5 μs flat top. The modulator generates 2.0 μs pulses with 37 kV voltage and 7,300 A peak current for the operation of the XB-72K. It is a conventional line-type modulator with a 6 section pulse forming network (PFN) which is resonantly charged and discharged by a thyratron switch at up to 200 pps. In order to reduce the size of the modulator, a special low inductance capacitors using a film coated thin Al-electrodes of 300 angstrom thickness has been developed for the PFN. Its output pulse voltage is stepped up to 15 times by a pulse transformer. The design, specifications and results of performance tests of the modulator are described in this paper

  3. An accelerated electrochemical MIC test for stainless alloys

    Previous work in our laboratory and elsewhere has suggested that microbially influenced corrosion (MIC) of stainless steels and nickel-base alloys occurs in locally anaerobic regions that support the growth of sulfate-reducing bacteria (SRB). The cathodic reaction is provided by oxygen reduction at remote sites. Such a coupling between anode and cathode is difficult to reproduce in the laboratory, but can be simulated indirectly using a double electrochemical cell, as in previous work. A more realistic simulation using a single aerated electrochemical cell has now been developed, in which a second organism (P. aeruginosa) is used to provide an anoxic habitat for SRB growth and possible a source of organic carbon, within a layer of silt. A bare alloy electrode is used as the oxygen cathode. Tests of this kind using rigorous microbiological procedures have generated pitting corrosion of several alloys in low chloride media simulating freshwater heat exchanger conditions. This report discusses the adaption of these procedures to study corrosion of nuclear waste containers. (author). 20 refs., 2 tabs., 7 figs

  4. Concept, implementation and commissioning of the automation system for the accelerator module test facility AMTF

    The European XFEL project launched on June 5, 2007 will require about 103 accelerator modules as a main part of the XFEL linear accelerator. All superconducting components constituting the accelerator module like cavities and magnets have to be tested before the assembly. For the tests of the individual cavities and the complete modules an XFEL Accelerator Module Test Facility (AMTF) has been erected at DESY. The process control system EPICS (Experimental Physics and Industrial Control System) is used to control and operate the cryogenic plant and all its subcomponents. A complementary component of EPICS is the Open Source software suit CSS (Control System Studio). CSS is an integrated engineering, maintenance and operating tool for EPICS. CSS enables local and remote operating and monitoring of the complete system and thus represents the human machine interface. More than 250 PROFIBUS nodes work at the accelerator module test facility. DESY installed an extensive diagnostic and condition monitoring system. With these diagnostic tools it is possible to examine the correct installation and configuration of all PROFIBUS nodes in real time. The condition monitoring system based on FDT/DTM technology shows the state of the PROFIBUS devices at a glance. This information can be used for preventive maintenance which is mandatory for continuous operation of the AMTF facility. The poster will describe all steps form engineering to implementation and commissioning

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

    J. Francfort (INEEL); J. Argueta; M. Wehrey (Southern California Edison); D. Karner; L. Tyree (Electric Transportation Applications)

    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.

  6. 3.9 GHz superconducting accelerating 9-cell cavity vertical test results

    Khabiboulline, Timergali; Cooper, Charles; Dhanaraj, Nandhini; Edwards, Helen; Foley, Mike; Harms, Elvin; Mitchell, Donald; Rowe, Allan; Solyak, Nikolay; /Fermilab; Moeller, Wolf-Dietrich; /DESY

    2007-06-01

    The 3rd harmonic 3.9GHz accelerating cavity was proposed to improve the beam performance of the FLASH (TTF/DESY) facility [1]. In the frame of a collaborative agreement, Fermilab will provide DESY with a cryomodule containing a string of four cavities. In addition, a second cryomodule with one cavity will be fabricated for installation in the Fermilab photo-injector, which will be upgraded for the ILC accelerator test facility. The first 9-cell Nb cavities were tested in a vertical setup and they didn't reach the designed accelerating gradient [2]. The main problem was a multipactor in the HOM couplers, which lead to overheating and quenching of the HOM couplers. New HOM couplers with improved design are integrated in the next 9-cell cavities. In this paper we present all results of the vertical tests.

  7. High Power RF Test of the Digital Feedback Control System for the PEFP Accelerator

    To control the RF field in the accelerating cavity for the PEFP (Proton Engineering Frontier Project) proton accelerator, a digital feedback control system has been developed. The stability requirements of the RF field are ±1% in amplitude and ± .deg. in phase. The digital feedback control system is based on the commercial FPGA PMC board hosted in VME board. The analog front-end was also developed which contains the IQ modulator, RF mixer, attenuators etc. To check the performance of the digital feedback control system, low power test with a dummy cavity has been performed with an intentional perturbation and shown that the feedback system rejected the perturbation as expected. High power RF test with a klystron has been performed and an accelerating field profile was measured. In addition, the pulse-to-pulse stability was checked by pulse operation with 0.1 Hz repetition rate. The detailed high power test results will be given in this paper

  8. Status and Plans for a Superconducting RF Accelerator Test Facility at Fermilab

    Leibfritz, J; Baffes, C M; Carlson, K; Chase, B; Church, M D; Harms, E R; Klebaner, A L; Kucera, M; Martinez, A; Nagaitsev, S; Nobrega, L E; Piot, P; Reid, J; Wendt, M; Wesseln, S J

    2013-01-01

    The Advanced Superconducting Test Acccelerator (ASTA) is being constructed at Fermilab. The existing New Muon Lab (NML) building is being converted for this facility. The accelerator will consist of an electron gun, injector, beam acceleration section consisting of 3 TTF-type or ILC-type cryomodules, multiple downstream beamlines for testing diagnostics and conducting various beam tests, and a high power beam dump. When completed, it is envisioned that this facility will initially be capable of generating a 750-MeV electron beam with ILC beam intensity. An expansion of this facility was recently completed that will provide the capability to upgrade the accelerator to a total beam energy of 1.5-GeV. Two new buildings were also constructed adjacent to the ASTA facility to house a new cryogenic plant and multiple superconducting RF (SRF) cryomodule test stands. In addition to testing accelerator components, this facility will be used to test RF power systems, instrumentation, and control systems for future SRF a...

  9. A high-gradient test of a 30 GHz copper accelerating structure

    Corsini, Roberto; Fandos, Raquel; Grudiev, Alexei; Jensen, Erk; Mete, Oznur; Ramsvik, Trond; Rodríguez, José Alberto; Sladen, Jonathan P H; Syratchev, Igor V; Taborelli, Mauro; Tecker, Frank A; Urschütz, Peter; Wilson, Ian H; Wuensch, Walter

    2006-01-01

    The CLIC study is investigating a number of different materials at different frequencies in order to find ways to increase achievable accelerating gradient and to understand what are the important parameters for high-gradient operation. So far a series of rf tests have been made with a set of identical-geometry 30 GHz and X-band structures in copper, tungsten and molybdenum. A new test of a 30 GHz copper accelerating structure has been completed in CTF3 with pulse lengths up to 70 ns. The new results are presented and compared to the previous structures to determine dependencies of quantities such accelerating gradient, material, frequency, pulse length, conditioning rate, breakdown rate and surface damage.

  10. Testing and interfacing intelligent power supplies for the Los Alamos National Laboratory Accelerator Complex

    New high-current, high precision microprocessor-controlled power supplies, built by Alpha Scientific Electronics of Hayward, CA, have been installed at the Los Alamos National Laboratory Accelerator Complex. Each unit has sophisticated microprocessor control on-board and communicates via RS-422 (serial communications). The units use a high level ASCII-based control protocol. Performance tests were conducted to verify adherence to specification and to ascertain ultimate long-term stability. The front-end software used by the accelerator control system has been written to accommodate these new devices. The supplies are interfaced to the control system through a terminal server port connected to the site-wide ethernet backbone. Test design and results as well as details of the software implementation for the analog and digital control of the supplies through the accelerator control system are presented

  11. Design and beam test of a high intensity continuous wave RFQ accelerator

    Zhang, Zhouli, E-mail: zhangzhouli@impcas.ac.cn; Sun, Liepeng; Jia, Huan; He, Yuan; Shi, Aimin; Du, Xiaonan; Wang, Jing; Jin, Xiaofeng; Pan, Gang; Xu, Xianbo; Li, Chenxing; Shi, Longbo; Lu, Liang; Zhang, Zimin; Wu, Junxia; Wang, Haoning; Zhu, Tieming; Wang, Xianwu; Guo, Yuhui; Liu, Yong; and others

    2014-11-01

    A four-vane continuous wave (CW) RFQ has been designed for the injector II LINAC of China ADS project. To acquire the experience of a CW RFQ on design, tuning, conditioning, running, etc., a 1-m-long RFQ accelerator prototype has been built. Working at 162.5 MHz, the RFQ prototype accelerates protons of 10 mA from 20 keV to 560 keV in one meter length with a low inter-vane voltage of 65 kV and a safe Kilpatric factor of 1.3. Conditioning and beam test of the accelerator prototype have been completed, and it shows the transmission efficiency can reach 90% with a 10 mA CW proton beam. Design, fabrication and tests of the RFQ prototype will be presented in detail in the paper.

  12. Test-particle acceleration in a hierarchical three-dimensional turbulence model

    Dalena, S.; Rappazzo, A. F.; Matthaeus, W. H. [Bartol Research Institute, Department of Physics and Astronomy, University of Delaware, DE 19716 (United States); Dmitruk, P. [Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428 Buenos Aires (Argentina); Greco, A., E-mail: serena.dalena@fis.unical.it [Dipartimento di Fisica, Università della Calabria, I-87036 Cosenza (Italy)

    2014-03-10

    The acceleration of charged particles is relevant to the solar corona over a broad range of scales and energies. High-energy particles are usually detected in concomitance with large energy release events like solar eruptions and flares. Nevertheless, acceleration can occur at smaller scales, characterized by dynamical activity near current sheets. To gain insight into the complex scenario of coronal charged particle acceleration, we investigate the properties of acceleration with a test-particle approach using three-dimensional magnetohydrodynamic (MHD) models. These are obtained from direct solutions of the reduced MHD equations, well suited for a plasma embedded in a strong axial magnetic field, relevant to the inner heliosphere. A multi-box, multiscale technique is used to solve the equations of motion for protons. This method allows us to resolve an extended range of scales present in the system, namely, from the ion inertial scale of the order of a meter up to macroscopic scales of the order of 10 km (1/100th of the outer scale of the system). This new technique is useful to identify the mechanisms that, acting at different scales, are responsible for acceleration to high energies of a small fraction of the particles in the coronal plasma. We report results that describe acceleration at different stages over a broad range of time, length, and energy scales.

  13. Design and test results of the Low Energy Demonstration Accelerator (LEDA) RF systems

    The Low Energy Demonstration Accelerator (LEDA) being constructed at Los Alamos will serve as the prototype for the low energy section of the Accelerator Production of Tritium (APT) accelerator. The APT accelerator requires over 200 RF systems each with a continuous wave output power of 1 MW. The reliability and availability of these RF systems is critical to the successful operation of the APT plant and prototypes of these systems are being developed and demonstrated on LEDA. The RF system design for LEDA includes three, 1.2 MW, 350 MHz continuous wave (CW), RF systems driving a radio frequency quadrupole (RFQ) and one, 1.0 MW, CW, RF system driving a coupled-cavity drift tube linac (CCDTL). This paper presents the design and test results for these RF systems including the klystrons, cathode power supply, circulators, RF vacuum windows, accelerator field and resonance control system, and RF transmission components. The three RF systems driving the RFQ use the accelerating structure as a power combiner, and this places some unique requirements on the RF system. These requirements and corresponding operational implications will be discussed

  14. The conversion of CESR to operate as the Test Accelerator, CesrTA. Part 1: overview

    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.

  15. The conversion of CESR to operate as the Test Accelerator, CesrTA. Part 1: overview

    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

  16. Equipment for controlling test benches charged particle accelerator pulse power supply systems

    Composition of the off-line and manual control device system designed for experimental testing the pulse supply systems of charged particle accelereators is considered. The system includes following devices: a manual remote control desk, a sysnchronization device with fibre-optical commutation programmed pulse shape generator digital sources of reference voltage. Performances of all these devices are presented. 1 ref

  17. Lifetime Prediction for Degradation of Solar Mirrors using Step-Stress Accelerated Testing (Presentation)

    Lee, J.; Elmore, R.; Kennedy, C.; Gray, M.; Jones, W.

    2011-09-01

    This research is to illustrate the use of statistical inference techniques in order to quantify the uncertainty surrounding reliability estimates in a step-stress accelerated degradation testing (SSADT) scenario. SSADT can be used when a researcher is faced with a resource-constrained environment, e.g., limits on chamber time or on the number of units to test. We apply the SSADT methodology to a degradation experiment involving concentrated solar power (CSP) mirrors and compare the results to a more traditional multiple accelerated testing paradigm. Specifically, our work includes: (1) designing a durability testing plan for solar mirrors (3M's new improved silvered acrylic "Solar Reflector Film (SFM) 1100") through the ultra-accelerated weathering system (UAWS), (2) defining degradation paths of optical performance based on the SSADT model which is accelerated by high UV-radiant exposure, and (3) developing service lifetime prediction models for solar mirrors using advanced statistical inference. We use the method of least squares to estimate the model parameters and this serves as the basis for the statistical inference in SSADT. Several quantities of interest can be estimated from this procedure, e.g., mean-time-to-failure (MTTF) and warranty time. The methods allow for the estimation of quantities that may be of interest to the domain scientists.

  18. Beam Extraction for 1-MV Electrostatic Accelerator at the 300 kV Test Stand

    The Korea Multipurpose Accelerator Complex (KOMAC) has been developing a 300-kV test stand for a 1-MV electrostatic accelerator ion source. The ion source in the high-pressure vessel is required to have a high reliability. The test stand has been proposed and developed to confirm the stable operating conditions of the ion source. The ion source will be tested at the test stand to verify the long-time operating conditions. The test stand comprises a 300-kV high-voltage terminal, a battery for the ion-source power, a 60-Hz inverter, 200-MHz RF power, a 5-kV extraction power supply, a 300-kV accelerating tube, and a vacuum system. A beam extraction experiment for the test stand was performed, and the beam current was measured using a faraday cup in the chamber. A beam extraction results for the RF ion source will be presented. Beam extraction from the RF ion source of the test stand is verified by measuring the beam current with a faraday cup in the chamber. Thus far NI Labview, PLC and faraday cup have been used to measure the beam current. The OPC server is useful for monitoring the PLC values. The average beam current of (a), (b) and (c) shown in figure 2 are 110.241µA, 105.8597µA and 103.5278µA respectively

  19. First Beam and High-Gradient Cryomodule Commissioning Results of the Advanced Superconducting Test Accelerator at Fermilab

    Crawford, Darren; et al.

    2015-06-01

    The advanced superconducting test accelerator at Fermilab has accelerated electrons to 20 MeV and, separately, the International Linear Collider (ILC) style 8-cavity cryomodule has achieved the ILC performance milestone of 31.5 MV/m per cavity. When fully completed, the accelerator will consist of a photoinjector, one ILC-type cryomodule, multiple accelerator R&D beamlines, and a downstream beamline to inject 300 MeV electrons into the Integrable Optics Test Accelerator (IOTA). We report on the results of first beam, the achievement of our cryomodule to ILC gradient specifications, and near-term future plans for the facility.

  20. NDT for concrete under accelerated freeze/thaw tests and surface scaling

    Romero Mendoza, Héctor Leonardo; Casati Calzada, María Jesús; Gálvez Ruíz, Jaime

    2011-01-01

    Freezing of water or salt solution in concrete pores is a main cause for severe damage and significant reduction of the service life. Most of the freeze-thaw (F-T) accelerated tests measure the scaling of concrete by weighting. This paper presents complementary procedures based on the use of strain gages and ultrasonic pulse velocity (UPV) for measuring the deterioration of concrete due to freezing and thawing. These non-destructive testing (NDT) procedures are applied to two types of con...

  1. Accelerated Test Method to Identify Freeze-Thaw Durability of Aggregates

    Desta, Belayneh B.; Whiting, Nancy

    2015-01-01

    INDOT currently identifies freeze-thaw durable aggregate using ITM210, a 90-day concrete beam freeze-thaw test. To accelerate this procedure, the 8-day Hydraulic Fracture Test (HFT) was investigated and modified. Samples from 18 quarries and six RCA sources were subjected to HFT and ITM210. Statistical analysis demonstrated that HFT can predict the ITM210 results with reasonable accuracy. The modified HFT procedures and equipment are recommended as a quick screening tool for predicting ITM210...

  2. Accelerated swell testing of artificial sulfate bearing lime stabilised cohesive soils

    Buttress, A.J.; Grenfell, J.R.A.; Airey, G.D.

    2014-01-01

    This paper reports on the physico-chemical response of two lime stabilised sulfate bearing artificial soils subject to the European Accelerated Volumetric Swell Test (EN13286-49). At various intervals during the test, a specimen was removed and subject to compositional and microstructural analysis. Ettringite was formed by both soils types, but with significant differences in crystal morphology. Ettringite crystals formed from kaolin based soils were very small, colloidal in size and tended t...

  3. Testing of a low pressure multiwire avalanche counter with heavy ions from the Pelletron accelerator, Mumbai

    The motivation is to investigate eta-nucleus interaction for which the available experimental information is scarce. The new system consists of two multiwire avalanche counters (MWAC) to be operated at low pressure (10-20 mbar) followed by two layers of thin plastic scintillators. The MWACs will provide position information for track reconstruction. The chambers were tested with heavy ions from the pelletron accelerator, Mumbai. The test measurement is reported here

  4. The Ground Test Accelerator control system database: Configuration, run-time operation, and access

    A database is used to implement the interface between the control system and the accelerator and to provide flexibility in configuring the I/O. This flexibility is necessary to allow the control system to keep pace with the changing requirements that are inherent in an experimental environmental environment. This is not achieved without cost. Problems often associated with using databases are painful data entry, poor performance, and embedded knowledge of the database structure in code throughout the control system. This report describes how the database configuration, access, conversion, and execution in the Ground Test Accelerator (GTA) Control System overcome these problems. 2 figs

  5. ACCELERATED AGING TEST IN DETERMINING THE VIGOUR OF SUNFLOWER SEEDS WITH AND WITHOUT PERICARP

    K. R. Ducatti

    2014-09-01

    Full Text Available The standard germination test alone is insufficient to attest the quality of seeds, making necessary correlation’s with vigour tests, to determine more accurately the physiological potential of a seeds lot. The accelerated aging test is an option for determine the vigour and consists in submits seeds to high temperatures and humidity, for different periods of time, has not yet standardized. The objective of this work was to analyze the efficiency of the accelerated aging test in the assessment of the effect of a lot of sunflower seed, by three periods of aging (48, 56 and 72 hours in 42 °C temperature, in seeds with and without pericarp (manually removed and relate the results with electrical conductivity test and germination first count. The experimental design was a completely randomized design and the comparison of averages made using Tukey's test at 5% probability. The results showed that standard germination, electrical conductivity and germination first count, the seeds without pericarp showed better performance. In relation to the accelerated aging, only in the period of 72 hours of aging there was no significant difference between the treatments. In this way, the appropriate period to identify differences in force between the treatments was 72 hours, which showed a positive correlation with the germination first count and electrical conductivity.

  6. Thermal vacuum accelerated life test of the unit qualification model msds 3 marconi low speed mechanism

    Appleton, D.A.

    1975-01-01

    The thermal vacuum accelerated life test of a solar array unit qualification mechanism (MSDS 3) is described. Most of the test was conducted with the shaft of the mechanism rotating at one revolution per hour, which is 24 times normal speed. The test was conducted at two different temperature conditions, and included additional thermal cycling of the shaft temperature to simulate conditions of earth eclipse of a satellite in a geostationary orbit. Throughout the test there was no change in the motor power required to drive the shaft, and the electrical noise levels on the slip rings showed no significant deterioration.

  7. Overview of the Beam diagnostics in the Medaustron Accelerator:Design choices and test Beam commissioning

    Osmic, F; Gyorgy, A; Kerschbaum, A; Repovz, M; Schwarz, S; Neustadt, W; Burtin, G

    2012-01-01

    The MedAustron centre is a synchrotron based accelerator complex for cancer treatment and clinical and non-clinical research with protons and light ions, currently under construction in Wiener Neustadt, Austria. The accelerator complex is based on the CERN-PIMMS study [1] and its technical implementation by the Italian CNAO foundation in Pavia [2]. The MedAustron beam diagnostics system is based on sixteen different monitor types (153 devices in total) and will allow measuring all relevant beam parameters from the source to the irradiation rooms. The monitors will have to cope with large intensities and energy ranges. Currently, one ion source, the low energy beam transfer line and the RFQ are being commissioned in the Injector Test Stand (ITS) at CERN. This paper gives an overview of all beam monitors foreseen for the MedAustron accelerator, elaborates some of the design choices and reports the first beam commissioning results from the ITS.

  8. Design, Construction and Test Arrangement of a Fast-Cycling HTS Accelerator Magnet

    Piekarz, H; Hays, Steven; Shiltsev, Vladimir

    2014-01-01

    Design, fabrication and assembly of a novel fast-cycling accelerator magnet is presented. A short-sample magnet is powered with a single-turn HTS cable capable to carry 80 kA current at 20 K and generate 1.75 T field in a 40 mm magnet gap. The applied conventional leads and the power supply, however, allow only for a sin-wave 24 kA, 20 Hz current limiting test magnet to a B-field of 0.5 T and to a maximum cycling rate of 20 T/s. The critical aspects of the cable construction and the splicing connection to the power leads are described. Tentative power losses of the proposed HTS accelerator magnet in a possible application for proton and muon accelerators are presented.

  9. Measuring test mass acceleration noise in space-based gravitational wave astronomy

    Congedo, Giuseppe

    2015-03-01

    The basic constituent of interferometric gravitational wave detectors—the test-mass-to-test-mass interferometric link—behaves as a differential dynamometer measuring effective differential forces, comprising an integrated measure of gravity curvature, inertial effects, as well as nongravitational spurious forces. This last contribution is going to be characterized by the LISA Pathfinder mission, a technology precursor of future space-borne detectors like eLISA. Changing the perspective from displacement to acceleration can benefit the data analysis of LISA Pathfinder and future detectors. The response in differential acceleration to gravitational waves is derived for a space-based detector's interferometric link. The acceleration formalism can also be integrated into time delay interferometry by building up the unequal-arm Michelson differential acceleration combination. The differential acceleration is nominally insensitive to the system's free evolution dominating the slow displacement dynamics of low-frequency detectors. Working with acceleration also provides an effective way to subtract measured signals acting as systematics, including the actuation forces. Because of the strong similarity with the equations of motion, the optimal subtraction of systematic signals, known within some amplitude and time shift, with the focus on measuring the noise provides an effective way to solve the problem and marginalize over nuisance parameters. The F statistic, in widespread use throughout the gravitation waves community, is included in the method and suitably generalized to marginalize over linear parameters and noise at the same time. The method is applied to LPF simulator data and, thanks to its generality, can also be applied to the data reduction and analysis of future gravitational wave detectors.

  10. Correlating outdoor exposure with accelerated aging tests for aluminum solar reflectors

    Wette, Johannes; Sutter, Florian; Fernández-García, Aránzazu

    2016-05-01

    Guaranteeing the durability of concentrated solar power (CSP) components is crucial for the success of the technology. The reflectors of the solar field are a key component of CSP plants, requiring reliable methods for service lifetime prediction. So far, no proven correlations exist to relate accelerated aging test results in climate chambers with relevant CSP exposure sites. In this work, correlations have been derived for selected testing conditions that excite the same degradation mechanisms as for outdoor exposure. Those testing conditions have been identified by performing an extensive microscopic comparison of the appearing degradation mechanisms on reference samples that have been weathered outdoors with samples that underwent a high variety of accelerated aging experiments. The herein developed methodology is derived for aluminum reflectors and future work will study its applicability to silvered-glass mirrors.

  11. Characterization of Corrosion Products on Carbon Steel Exposed to Natural Weathering and to Accelerated Corrosion Tests

    Renato Altobelli Antunes

    2014-01-01

    Full Text Available The aim of this work was to compare the corrosion products formed on carbon steel plates submitted to atmospheric corrosion in urban and industrial atmospheres with those formed after accelerated corrosion tests. The corrosion products were characterized by X-ray diffraction, Mössbauer spectroscopy, and Raman spectroscopy. The specimens were exposed to natural weathering in both atmospheres for nine months. The morphologies of the corrosion products were evaluated using scanning electron microscopy. The main product found was lepidocrocite. Goethite and magnetite were also found on the corroded specimens but in lower concentrations. The results showed that the accelerated test based on the ASTM B117 procedure presented poor correlation with the atmospheric corrosion tests whereas an alternated fog/dry cycle combined with UV radiation exposure provided better correlation.

  12. The Conversion of CESR to Operate as the Test Accelerator, CesrTA, Part 1: Overview

    Billing, M G

    2015-01-01

    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, capabl...

  13. A cosmic speed-trap: a gravity-independent test of cosmic acceleration using baryon acoustic oscillations

    Sutherland, Will

    2011-01-01

    We propose a new and highly model-independent test of cosmic acceleration by comparing observations of the baryon acoustic oscillation (BAO) scale at low and intermediate redshifts: we derive a new inequality relating BAO observables at two distinct redshifts, which must be satisfied for any reasonable homogeneous non-accelerating model, but is violated by models similar to LambdaCDM, due to acceleration in the recent past. This test is fully independent of the theory of gravity (GR or otherw...

  14. Selenide isotope generator for the Galileo Mission. Axially-grooved heat pipe: accelerated life test results

    The results through SIG/Galileo contract close-out of accelerated life testing performed from June 1978 to June 1979 on axially-grooved, copper/water heat pipes are presented. The primary objective of the test was to determine the expected lifetime of axially-grooved copper/water heat pipes. The heat pipe failure rate, due to either a leak or a build-up of non-condensible gas, was determined. The secondary objective of the test was to determine the effects of time and temperature on the thermal performance parameters relevant to long-term (> 50,000 h) operation on a space power generator. The results showed that the gas generation rate appears to be constant with time after an initial sharp rise although there are indications that it drops to approximately zero beyond approx. 2000 h. During the life test, the following pipe-hours were accumulated: 159,000 at 1250C, 54,000 at 1650C, 48,000 at 1850C, and 8500 at 2250C. Heated hours per pipe ranged from 1000 to 7500 with an average of 4720. Applying calculated acceleration factors yields the equivalent of 930,000 pipe-h at 1250C. Including the accelerated hours on vendor tested pipes raises this number to 1,430,000 pipe-hours at 1250C. It was concluded that, for a heat pipe temperature of 1250C and a mission time of 50,000 h, the demonstrated heat pipe reliability is between 80% (based on 159,000 actual pipe-h at 1250C) and 98% (based on 1,430,000 accelerated pipe-h at 1250C). Measurements indicate some degradation of heat transfer with time, but no detectable degradation of heat transport

  15. Optimum Accelerated Degradation Tests for the Gamma Degradation Process Case under the Constraint of Total Cost

    Heonsang Lim

    2015-04-01

    Full Text Available An accelerated degradation test (ADT is regarded as an effective alternative to an accelerated life test in the sense that an ADT can provide more accurate information on product reliability, even when few or no failures may be expected before the end of a practical test period. In this paper, statistical methods for optimal designing ADT plans are developed assuming that the degradation characteristic follows a gamma process (GP. The GP-based approach has an advantage that it can deal with more frequently encountered situations in which the degradation should always be nonnegative and strictly increasing over time. The optimal ADT plan is developed under the total experimental cost constraint by determining the optimal settings of variables such as the number of measurements, the measurement times, the test stress levels and the number of units allocated to each stress level such that the asymptotic variance of the maximum likelihood estimator of the q-th quantile of the lifetime distribution at the use condition is minimized. In addition, compromise plans are developed to provide means to check the adequacy of the assumed acceleration model. Finally, sensitivity analysis procedures for assessing the effects of the uncertainties in the pre-estimates of unknown parameters are illustrated with an example.

  16. ADVANCED X-BAND TEST ACCELERATOR FOR HIGH BRIGHTNESS ELECTRON AND GAMMA RAY BEAMS

    Marsh, R A; Anderson, S G; Barty, C P; Chu, T S; Ebbers, C A; Gibson, D J; Hartemann, F V; Adolphsen, C; Jongewaard, E N; Raubenheimer, T; Tantawi, S G; Vlieks, A E; Wang, J W

    2010-05-12

    In support of Compton scattering gamma-ray source efforts at LLNL, a multi-bunch test stand is being developed to investigate accelerator optimization for future upgrades. This test stand will enable work to explore the science and technology paths required to boost the current 10 Hz monoenergetic gamma-ray (MEGa-Ray) technology to an effective repetition rate exceeding 1 kHz, potentially increasing the average gamma-ray brightness by two orders of magnitude. Multiple bunches must be of exceedingly high quality to produce narrow-bandwidth gamma-rays. Modeling efforts will be presented, along with plans for a multi-bunch test stand at LLNL. The test stand will consist of a 5.5 cell X-band rf photoinjector, single accelerator section, and beam diagnostics. The photoinjector will be a high gradient standing wave structure, featuring a dual feed racetrack coupler. The accelerator will increase the electron energy so that the emittance can be measured using quadrupole scanning techniques. Multi-bunch diagnostics will be developed so that the beam quality can be measured and compared with theory. Design will be presented with modeling simulations, and layout plans.

  17. Advanced X-Band Test Accelerator for High Brightness Electron and Gamma Ray Beams

    Marsh, Roark; /LLNL, Livermore; Anderson, Scott; /LLNL, Livermore; Barty, Christopher; /LLNL, Livermore; Chu, Tak Sum; /LLNL, Livermore; Ebbers, Chris; /LLNL, Livermore; Gibson, David; /LLNL, Livermore; Hartemann, Fred; /LLNL, Livermore; Adolphsen, Chris; /SLAC; Jongewaard, Erik; /SLAC; Raubenheimer, Tor; /SLAC; Tantawi, Sami; /SLAC; Vlieks, Arnold; /SLAC; Wang, Juwen; /SLAC

    2012-07-03

    In support of Compton scattering gamma-ray source efforts at LLNL, a multi-bunch test stand is being developed to investigate accelerator optimization for future upgrades. This test stand will enable work to explore the science and technology paths required to boost the current 10 Hz monoenergetic gamma-ray (MEGa-Ray) technology to an effective repetition rate exceeding 1 kHz, potentially increasing the average gamma-ray brightness by two orders of magnitude. Multiple bunches must be of exceedingly high quality to produce narrow-bandwidth gamma-rays. Modeling efforts will be presented, along with plans for a multi-bunch test stand at LLNL. The test stand will consist of a 5.5 cell X-band rf photoinjector, single accelerator section, and beam diagnostics. The photoinjector will be a high gradient standing wave structure, featuring a dual feed racetrack coupler. The accelerator will increase the electron energy so that the emittance can be measured using quadrupole scanning techniques. Multi-bunch diagnostics will be developed so that the beam quality can be measured and compared with theory. Design will be presented with modeling simulations, and layout plans.

  18. Accelerated corrosion test and corrosion failure distribution model of aircraft structural aluminum alloy

    LIU Wen-lin; MU Zhi-tao; JIN Ping

    2006-01-01

    Based on corrosion damage data of 10 years for a type of aircraft aluminum alloy, the statistical analysis was conducted by Gumbel, Normal and two parameters Weibull distribution function. The results show that aluminum alloy structural member has the corrosion history of pitting corrosion-intergranular corrosion-exfoliation corrosion, and the maximum corrosion depth is in conformity to normal distribution. The accelerated corrosion test was carried out with the complied equivalent airport accelerated environment spectrum. The corrosion damage failure modes of aluminum alloy structural member indicate that the period of validity of the former protective coating is about 2.5 to 3 years, and that of the novel protective coating is about 4.0 to 4.5 years. The corrosion kinetics law of aluminum spar flange was established by fitting corrosion damage test data. The law indicates two apparent corrosion stages of high strength aluminum alloy section material: pitting corrosion and intergranular corrosion/exfoliation corrosion.The test results agree with the statistical fit result of corrosion data collected from corrosion member in service. The fractional error is 5.8% at the same calendar year. The accelerated corrosion test validates the corrosion kinetics law of aircraft aluminum alloy in service.

  19. 78 FR 76410 - Request for Information on Strategies To Accelerate the Testing and Adoption of Pay for Success...

    2013-12-17

    ... Strategies to Accelerate the Testing and Adoption of Pay for Success (PFS) Financing Models (78 FR 60998... Request for Information on Strategies To Accelerate the Testing and Adoption of Pay for Success (PFS... information; reopening of comment period. SUMMARY: The Department of the Treasury is reopening the...

  20. Ageing evaluation of low voltage cables and insulators with gamma ray irradiation and thermal accelerated ageing tests

    To optimize lifetime prediction method of cables and to understand cable ageing mechanism, ageing evaluation of low voltage cables and insulators with gamma ray irradiation and thermal accelerated ageing tests were conducted. Insulators had no indication of the ageing after 1000 hours of the accelerated ageing tests. (author)

  1. Current state of X-band accelerating structure high gradient test. Be held at high energy accelerator organization on April 15, 2005

    XTF (X-band Test Facility, Old name is GLCTA) is the high gradient test facility for X-band acceleration. We have installed an X-band 60cm structure (KX01) in the April 2004 and have been processing it for more than 10 months. Now it is under test on long-term operation. We report here the high gradient test result to date. (author)

  2. LLRF and timing system for the SCSS test accelerator at SPring-8

    Otake, Yuji; Ohshima, Takashi; Hosoda, Naoyasu; Maesaka, Hirokazu; Fukui, Toru; Kitamura, Masanobu; Shintake, Tsumoru

    2012-12-01

    The 250 MeV SCSS test accelerator as an extreme-ultra violet (EUV) laser source has been built at SPring-8. The accelerator comprises a 500 kV thermionic gun, a velocity bunching system using multi-sub-harmonic bunchers (SHB) in an injector and a magnetic bunch compressor using a chicane of 4 bending magnets, a 5712 MHz main accelerator to accelerate an electron beam up to 250 MeV, and undulators to radiate the EUV laser. These bunch compression processes make short bunched electrons with a 300 A peak current and a 300 fs pulse width. The pulse width and peak current of an electron beam, which strongly affect the pulse width and intensity of the laser light, are mainly decided by the pulse compression ratio of the velocity bunching and the magnetic bunch compressing processes. The compression ratio is also determined due to an energy chirp along the beam bunch generated by an off-crest rf field at the SHB and cavities before the chicane. To constantly keep the beam pulse-width conducted by rf and timing signals, which are temporally controlled within subpicoseconds of the designed value, the low-level rf and timing system of the test accelerator has been developed. The system comprises a very low-noise and temporally stable reference signal source, in-phase and quadrature (IQ) modulators and demodulators, as well as VME type 12 bits analog-to-digital and digital-to-analog converter modules to manipulate an rf phase and amplitude by IQ functions for the cavity. We achieved that the SSB noise of the 5712 MHz reference signal source was less than -120 dBc/Hz at 1 kHz offset from the reference frequency; the phase setting and detecting resolution of the IQ-modulators and demodulators were within +/-0.5° at 5712 MHz. A master trigger VME module and a trigger delay VME module were also developed to activate the components of the test accelerator. The time jitter of the delay module was less than 0.7 ps, sufficient for our present requirement. As a result, a beam energy

  3. LLRF and timing system for the SCSS test accelerator at SPring-8

    The 250 MeV SCSS test accelerator as an extreme-ultra violet (EUV) laser source has been built at SPring-8. The accelerator comprises a 500 kV thermionic gun, a velocity bunching system using multi-sub-harmonic bunchers (SHB) in an injector and a magnetic bunch compressor using a chicane of 4 bending magnets, a 5712 MHz main accelerator to accelerate an electron beam up to 250 MeV, and undulators to radiate the EUV laser. These bunch compression processes make short bunched electrons with a 300 A peak current and a 300 fs pulse width. The pulse width and peak current of an electron beam, which strongly affect the pulse width and intensity of the laser light, are mainly decided by the pulse compression ratio of the velocity bunching and the magnetic bunch compressing processes. The compression ratio is also determined due to an energy chirp along the beam bunch generated by an off-crest rf field at the SHB and cavities before the chicane. To constantly keep the beam pulse-width conducted by rf and timing signals, which are temporally controlled within subpicoseconds of the designed value, the low-level rf and timing system of the test accelerator has been developed. The system comprises a very low-noise and temporally stable reference signal source, in-phase and quadrature (IQ) modulators and demodulators, as well as VME type 12 bits analog-to-digital and digital-to-analog converter modules to manipulate an rf phase and amplitude by IQ functions for the cavity. We achieved that the SSB noise of the 5712 MHz reference signal source was less than −120 dBc/Hz at 1 kHz offset from the reference frequency; the phase setting and detecting resolution of the IQ-modulators and demodulators were within +/−0.5° at 5712 MHz. A master trigger VME module and a trigger delay VME module were also developed to activate the components of the test accelerator. The time jitter of the delay module was less than 0.7 ps, sufficient for our present requirement. As a result, a beam

  4. Accelerated Testing of UH-60 Viscous Bearings for Degraded Grease Fault

    Dykas, Brian; Hood, Adrian; Krantz, Timothy; Klemmer, Marko

    2015-01-01

    An accelerated aging investigation of critical aviation bearings lubricated with MIL-PRF- 81322 grease was conducted to derive an understanding of the mechanisms of grease degradation and loss of lubrication over time. The current study focuses on UH-60 Black Hawk viscous damper bearings supporting the tail rotor driveshaft, which were subjected to more than 5800 hours of testing in a heated environment to accelerate the deterioration of the grease. The mechanism of grease degradation is a reduction in the oil/thickener ratio rather than the expected chemical degradation of grease constituents. Over the course of testing, vibration and temperature monitoring of bearings was conducted and trends for failing bearings are presented.

  5. The Use of Conditional Probability Integral Transformation Method for Testing Accelerated Failure Time Models

    Abdalla Ahmed Abdel-Ghaly

    2016-06-01

    Full Text Available This paper suggests the use of the conditional probability integral transformation (CPIT method as a goodness of fit (GOF technique in the field of accelerated life testing (ALT, specifically for validating the underlying distributional assumption in accelerated failure time (AFT model. The method is based on transforming the data into independent and identically distributed (i.i.d Uniform (0, 1 random variables and then applying the modified Watson statistic to test the uniformity of the transformed random variables. This technique is used to validate each of the exponential, Weibull and lognormal distributions' assumptions in AFT model under constant stress and complete sampling. The performance of the CPIT method is investigated via a simulation study. It is concluded that this method performs well in case of exponential and lognormal distributions. Finally, a real life example is provided to illustrate the application of the proposed procedure.

  6. Characterization of Corrosion Products on Carbon Steel Exposed to Natural Weathering and to Accelerated Corrosion Tests

    Renato Altobelli Antunes; Rodrigo Uchida Ichikawa; Luis Gallego Martinez; Isolda Costa

    2014-01-01

    The aim of this work was to compare the corrosion products formed on carbon steel plates submitted to atmospheric corrosion in urban and industrial atmospheres with those formed after accelerated corrosion tests. The corrosion products were characterized by X-ray diffraction, Mössbauer spectroscopy, and Raman spectroscopy. The specimens were exposed to natural weathering in both atmospheres for nine months. The morphologies of the corrosion products were evaluated using scanning electron micr...

  7. Real time data acquisition system for the High Current Test Facility proton accelerator

    A real time data acquisition system was developed to monitor and control the High Current Test Facility Proton Accelerator. It is a PDP-8/E computer system with virtual memory capability that is fully interrupt driven and operates under a real-time, multi-tasking executive. The application package includes mode selection to automatically modify programs and optimize operation under varying conditions. (U.S.)

  8. Reliability Estimation based on Step-Stress Accelerated Degradation Testing by Unequal Interval Time Series Analysis

    Li Wang; Zaiwen Liu; Chongchong Yu

    2013-01-01

    This paper proposes a reliability estimation method based on Step-Stress Accelerated Degradation Testing (SSADT) data analysis using unequal interval time series analysis. A Multi-Regression Time Varying Auto-Regressive (MRTVAR) degradation time series model is proposed. Product SSADT data are treated as unequal interval composite time series and described using MRTVAR time series model and utilized to predict long-term trend of degradation. By using the suggested method, product reliability ...

  9. An experimental test of Newton's law of gravitation for small accelerations

    The experiment presented in this thesis has been designed to test Newton's law of gravitation in the limit of small accelerations caused by weak gravitational forces. It is located at DESY, Hamburg, and is a modification of an experiment that was carried out in Wuppertal, Germany, until 2002 in order to measure the gravitational constant G. The idea of testing Newton's law in the case of small accelerations emerged from the question whether the flat rotation curves of spiral galaxies can be traced back to Dark Matter or to a law of gravitation that deviates from Newton on cosmic scales like e.g. MOND (Modified Newtonian Dynamics). The core of this experiment is a microwave resonator which is formed by two spherical concave mirrors that are suspended as pendulums. Masses between 1 and 9 kg symmetrically change their distance to the mirrors from far to near positions. Due to the increased gravitational force the mirrors are pulled apart and the length of the resonator increases. This causes a shift of the resonance frequency which can be translated into a shift of the mirror distance. The small masses are sources of weak gravitational forces and cause accelerations on the mirrors of about 10-10 m/s2. These forces are comparable to those between stars on cosmic scales and the accelerations are in the vicinity of the characteristic acceleration of MOND a0 ∼ 1.2.10-10 m/s2, where deviations from Newton's law are expected. Thus Newton's law could be directly checked for correctness under these conditions. First measurements show that due to the sensitivity of this experiment many systematic influences have to be accounted for in order to get consistent results. Newton's law has been confirmed with an accuracy of 3%. MOND has also been checked. In order to be able to distinguish Newton from MOND with other interpolation functions the accuracy of the experiment has to be improved. (orig.)

  10. Rapid estimation of lives of deficient superpave mixes and laboratory-based accelerated mix testing models

    Manandhar, Chandra Bahadur

    The engineers from the Kansas Department of Transportation (KDOT) often have to decide whether or not to accept non-conforming Superpave mixtures during construction. The first part of this study focused on estimating lives of deficient Superpave pavements incorporating nonconforming Superpave mixtures. These criteria were based on the Hamburg Wheel-Tracking Device (HWTD) test results and analysis. The second part of this study focused on developing accelerated mix testing models to considerably reduce test duration. To accomplish the first objective, nine fine-graded Superpave mixes of 12.5-mm nominal maximum aggregate size (NMAS) with asphalt grade PG 64-22 from six administrative districts of KDOT were selected. Specimens were prepared at three different target air void levels Ndesign gyrations and four target simulated in-place density levels with the Superpave gyratory compactor. Average number of wheel passes to 20-mm rut depth, creep slope, stripping slope, and stripping inflection point in HWTD tests were recorded and then used in the statistical analysis. Results showed that, in general, higher simulated in-place density up to a certain limit of 91% to 93%, results in a higher number of wheel passes until 20-mm rut depth in HWTD tests. A Superpave mixture with very low air voids Ndesign (2%) level performed very poorly in the HWTD test. HWTD tests were also performed on six 12.5-mm NMAS mixtures with air voids Ndesign of 4% for six projects, simulated in-place density of 93%, two temperature levels and five load levels with binder grades of PG 64-22, PG 64-28, and PG 70-22. Field cores of 150-mm in diameter from three projects in three KDOT districts with 12.5-mm NMAS and asphalt grade of PG 64-22 were also obtained and tested in HWTD for model evaluation. HWTD test results indicated as expected. Statistical analysis was performed and accelerated mix testing models were developed to determine the effect of increased temperature and load on the duration of

  11. Method for the Accelerated Testing of the Durability of a Construction Binder using the Arrhenius Approach

    Fridrichová Marcela

    2016-03-01

    Full Text Available The single most reliable indicator of a material’s durability is its performance in long-term tests, which cannot always be carried out due to a limited time budget. The second option is to perform some kind of accelerated durability tests. The aim of the work described in this article was to develop a method for the accelerated durability testing of binders. It was decided that the Arrhenius equation approach and the theory of chemical reaction kinetics would be applied in this case. The degradation process has been simplified to a single quantifiable parameter, which became compressive strength. A model hydraulic binder based on fluidised bed combustion ash (FBC ash was chosen as the test subject for the development of the method. The model binder and its hydration products were tested by high-temperature X-ray diffraction analysis. The main hydration product of this binder was ettringite. Due to the thermodynamic instability of this mineral, it was possible to verify the proposed method via long term testing. In order to accelerate the chemical reactions in the binder, four combinations of two temperatures (65 and 85°C and two different relative humidities (14 and 100% were used. The upper temperature limit was chosen because of the results of the high-temperature x-ray testing of the ettringite’s decomposition. The calculation formulae for the accelerated durability tests were derived on the basis of data regarding the decrease in compressive strength under the conditions imposed by the four above-mentioned combinations. The mineralogical composition of the binder after degradation was also described. The final degradation product was gypsum under dry conditions and monosulphate under wet conditions. The validity of the method and formula was subsequently verified by means of long-term testing. A very good correspondence between the calculated and real values was achieved. The deviation of these values did not exceed 5 %. The designed

  12. Method for the Accelerated Testing of the Durability of a Construction Binder using the Arrhenius Approach

    Fridrichová, Marcela; Dvořák, Karel; Gazdič, Dominik

    2016-03-01

    The single most reliable indicator of a material's durability is its performance in long-term tests, which cannot always be carried out due to a limited time budget. The second option is to perform some kind of accelerated durability tests. The aim of the work described in this article was to develop a method for the accelerated durability testing of binders. It was decided that the Arrhenius equation approach and the theory of chemical reaction kinetics would be applied in this case. The degradation process has been simplified to a single quantifiable parameter, which became compressive strength. A model hydraulic binder based on fluidised bed combustion ash (FBC ash) was chosen as the test subject for the development of the method. The model binder and its hydration products were tested by high-temperature X-ray diffraction analysis. The main hydration product of this binder was ettringite. Due to the thermodynamic instability of this mineral, it was possible to verify the proposed method via long term testing. In order to accelerate the chemical reactions in the binder, four combinations of two temperatures (65 and 85°C) and two different relative humidities (14 and 100%) were used. The upper temperature limit was chosen because of the results of the high-temperature x-ray testing of the ettringite's decomposition. The calculation formulae for the accelerated durability tests were derived on the basis of data regarding the decrease in compressive strength under the conditions imposed by the four above-mentioned combinations. The mineralogical composition of the binder after degradation was also described. The final degradation product was gypsum under dry conditions and monosulphate under wet conditions. The validity of the method and formula was subsequently verified by means of long-term testing. A very good correspondence between the calculated and real values was achieved. The deviation of these values did not exceed 5 %. The designed and verified method

  13. Comparison of test particle acceleration in torsional spine and fan reconnection regimes

    Hosseinpour, M., E-mail: hosseinpour@tabrizu.ac.ir; Mehdizade, M.; Mohammadi, M. A. [Plasma Physics Department, University of Tabriz, Tabriz (Iran, Islamic Republic of)

    2014-10-15

    Magnetic reconnection is a common phenomenon taking place in astrophysical and space plasmas, especially in solar flares which are rich sources of highly energetic particles. Torsional spine and fan reconnections are important mechanisms proposed for steady-state three-dimensional null-point reconnection. By using the magnetic and electric fields for these regimes, we numerically investigate the features of test particle acceleration in both regimes with input parameters for the solar corona. By comparison, torsional spine reconnection is found to be more efficient than torsional fan reconnection in an acceleration of a proton to a high kinetic energy. A proton can gain as high as 100 MeV of relativistic kinetic energy within only a few milliseconds. Moreover, in torsional spine reconnection, an accelerated particle can escape either along the spine axis or on the fan plane depending on its injection position. However, in torsional fan reconnection, the particle is only allowed to accelerate along the spine axis. In addition, in both regimes, the particle's trajectory and final kinetic energy depend on the injection position but adopting either spatially uniform or non-uniform localized plasma resistivity does not much influence the features of trajectory.

  14. Comparison of test particle acceleration in torsional spine and fan reconnection regimes

    Magnetic reconnection is a common phenomenon taking place in astrophysical and space plasmas, especially in solar flares which are rich sources of highly energetic particles. Torsional spine and fan reconnections are important mechanisms proposed for steady-state three-dimensional null-point reconnection. By using the magnetic and electric fields for these regimes, we numerically investigate the features of test particle acceleration in both regimes with input parameters for the solar corona. By comparison, torsional spine reconnection is found to be more efficient than torsional fan reconnection in an acceleration of a proton to a high kinetic energy. A proton can gain as high as 100 MeV of relativistic kinetic energy within only a few milliseconds. Moreover, in torsional spine reconnection, an accelerated particle can escape either along the spine axis or on the fan plane depending on its injection position. However, in torsional fan reconnection, the particle is only allowed to accelerate along the spine axis. In addition, in both regimes, the particle's trajectory and final kinetic energy depend on the injection position but adopting either spatially uniform or non-uniform localized plasma resistivity does not much influence the features of trajectory

  15. Performance and Environmental Test Results of the High Voltage Hall Accelerator Engineering Development Unit

    Kamhawi, Hani; Haag, Thomas; Huang, Wensheng; Shastry, Rohit; Pinero, Luis; Peterson, Todd; Mathers, Alex

    2012-01-01

    NASA Science Mission Directorate's In-Space Propulsion Technology Program is sponsoring the development of a 3.5 kW-class engineering development unit Hall thruster for implementation in NASA science and exploration missions. NASA Glenn and Aerojet are developing a high fidelity high voltage Hall accelerator that can achieve specific impulse magnitudes greater than 2,700 seconds and xenon throughput capability in excess of 300 kilograms. Performance, plume mappings, thermal characterization, and vibration tests of the high voltage Hall accelerator engineering development unit have been performed. Performance test results indicated that at 3.9 kW the thruster achieved a total thrust efficiency and specific impulse of 58%, and 2,700 sec, respectively. Thermal characterization tests indicated that the thruster component temperatures were within the prescribed material maximum operating temperature limits during full power thruster operation. Finally, thruster vibration tests indicated that the thruster survived the 3-axes qualification full-level random vibration test series. Pre and post-vibration test performance mappings indicated almost identical thruster performance. Finally, an update on the development progress of a power processing unit and a xenon feed system is provided.

  16. Limitations of predicting in vivo biostability of multiphase polyurethane elastomers using temperature-accelerated degradation testing.

    Padsalgikar, Ajay; Cosgriff-Hernandez, Elizabeth; Gallagher, Genevieve; Touchet, Tyler; Iacob, Ciprian; Mellin, Lisa; Norlin-Weissenrieder, Anna; Runt, James

    2015-01-01

    Polyurethane biostability has been the subject of intense research since the failure of polyether polyurethane pacemaker leads in the 1980s. Accelerated in vitro testing has been used to isolate degradation mechanisms and predict clinical performance of biomaterials. However, validation that in vitro methods reproduce in vivo degradation is critical to the selection of appropriate tests. High temperature has been proposed as a method to accelerate degradation. However, correlation of such data to in vivo performance is poor for polyurethanes due to the impact of temperature on microstructure. In this study, we characterize the lack of correlation between hydrolytic degradation predicted using a high temperature aging model of a polydimethylsiloxane-based polyurethane and its in vivo performance. Most notably, the predicted molecular weight and tensile property changes from the accelerated aging study did not correlate with clinical explants subjected to human biological stresses in real time through 5 years. Further, DMTA, ATR-FTIR, and SAXS experiments on samples aged for 2 weeks in PBS indicated greater phase separation in samples aged at 85°C compared to those aged at 37°C and unaged controls. These results confirm that microstructural changes occur at high temperatures that do not occur at in vivo temperatures. In addition, water absorption studies demonstrated that water saturation levels increased significantly with temperature. This study highlights that the multiphase morphology of polyurethane precludes the use of temperature accelerated biodegradation for the prediction of clinical performance and provides critical information in designing appropriate in vitro tests for this class of materials. PMID:24810790

  17. An electrochemical method for accelerated testing of chloride diffusivity in concrete

    Zhang, T.; Gjoerv, O.E. (Norwegian Inst. of Tech., Trondheim (Norway). Div. of Building Materials)

    1994-01-01

    In the present paper an electrochemical method for accelerated testing of chloride diffusivity in concrete is presented. The method is based on a theoretical relationship between chloride diffusivity and observed steady-state rate of chloride migration through the concrete. The concentration of the chloride source solution has a significant influence on the rate of chloride migration and, therefore, a correction factor for ionic interaction in the relationship is introduced. It is shown that the relationship can be used for calculation of chloride diffusivity under various testing conditions. Some experimental results are also presented.

  18. Accelerated life tests of specimen heat pipe from Communication Technology Satellite (CTS) project

    Tower, L. K.; Kaufman, W. B.

    1977-01-01

    A gas-loaded variable conductance heat pipe of stainless steel with methanol working fluid identical to one now on the CTS satellite was life tested in the laboratory at accelerated conditions for 14 200 hours, equivalent to about 70 000 hours at flight conditions. The noncondensible gas inventory increased about 20 percent over the original charge. The observed gas increase is estimated to increase operating temperature by about 2.2 C, insufficient to harm the electronic gear cooled by the heat pipes in the satellite. Tests of maximum heat input against evaporator elevation agree well with the manufacturer's predictions.

  19. Accelerated testing of solid oxide fuel cell stacks for micro combined heat and power application

    Hagen, Anke; Høgh, Jens Valdemar Thorvald; Barfod, Rasmus

    2015-12-01

    State-of-the-art (SoA) solid oxide fuel cell (SOFC) stacks are tested using profiles relevant for use in micro combined heat and power (CHP) units. Such applications are characterised by dynamic load profiles. In order to shorten the needed testing time and to investigate potential acceleration of degradation, the profiles are executed faster than required for real applications. Operation with fast load cycling, both using hydrogen and methane/steam as fuels, does not accelerate degradation compared to constant operation, which demonstrates the maturity of SoA stacks and enables transferring knowledge from testing at constant conditions to dynamic operation. 7.5 times more cycles than required for 80,000 h lifetime as micro CHP are achieved on one-cell-stack level. The results also suggest that degradation mechanisms that proceed on a longer time-scale, such as creep, might have a more dominating effect for long life-times than regular short time changes of operation. In order to address lifetime testing it is suggested to build a testing program consisting of defined modules that represent different application profiles, such as one module at constant conditions, followed by modules at one set of dynamic conditions etc.

  20. Power Test of the Ladder IH-RFQ Accelerator at Peking University

    LU Yuan-Rong; CHEN Wei; NIE Yuan-Cun; LIU Ge; GAO Shu-Li; ZENG Hong-Jin; YAN Xue-Qing; CHEN Jia-Er

    2011-01-01

    A 104-MHz ladder interdigital-H radio frequency quadrupole accelerator (T-IH-RFQ) is developed for applying RFQs to heavy ion implantation and accelerator-based mass spectroscopy in recent years at the Institute of Heavy Ion Physics,Peking University.It could accelerate ions with a mass-to-charge ratio of less than 14,from 2.9 ke V/u to 35.7keV/u within a length of 1.1 m.The T-IH-RFQ cavity operating at H21(0) mode was constructed successfully.Based on a well designed rf power feeding system,the cavity was cold measured and tested with high rf power.In the case of cold measurement,the rf properties were obtained using a vector network analyzer with the help of a perturbation capacitor. During a high power test,the inter-electrode voltage was derived from the energy spectrum of x-rays measured by a high purity Ge detector.The results show that the specific shunt impedance of the T-IH-RFQ cavity reaches 178kΩm,which could meet the requirements of beam dynamics design.

  1. Seismic-fragility tests of new and accelerated-aged Class 1E battery cells

    The seismic-fragility response of naturally-aged nuclear station safety-related batteries is of interest for two reasons: (1) to determine actual failure modes and thresholds and (2) to determine the validity of using the electrical capacity of individual cells as an indicator of the potential survivability of a battery given a seismic event. Prior reports in this series discussed the seismic-fragility tests and results for three specific naturally-aged cell types: 12-year old NCX-2250, 10-year old LCU-13, and 10-year old FHC-19. This report focuses on the complementary approach, namely, the seismic-fragility response of accelerated-aged batteries. Of particular interest is the degree to which such approaches accurately reproduce the actual failure modes and thresholds. In these tests the significant aging effects observed, in terms of seismic survivability, were: embrittlement of cell cases, positive bus material and positive plate grids; and excessive sulphation of positive plate active material causing hardening and expansion of positive plates. The IEEE Standard 535 accelerated aging method successfully reproduced seismically significant aging effects in new cells but accelerated grid embrittlement an estimated five years beyond the conditional age of other components

  2. Development of a quantitative accelerated sulphate attack test for mine backfill

    Shnorhokian, Shahe

    Mining operations produce large amounts of tailings that are either disposed of in surface impoundments or used in the production of backfill to be placed underground. Their mineralogy is determined by the local geology, and it is not uncommon to come across tailings with a relatively high sulphide mineral content, including pyrite and pyrrhotite. Sulphides oxidize in the presence of oxygen and water to produce sulphate and acidity. In the concrete industry, sulphate is known to produce detrimental effects by reacting with the cement paste to produce the minerals ettringite and gypsum. Because mine backfill uses tailings and binders---including cement---it is therefore prone to sulphate attack where the required conditions are met. Currently, laboratory tests on mine backfill mostly measure mechanical properties such as strength parameters, and the study of the chemical aspects is restricted to the impact of tailings on the environment. The potential of sulphate attack in mine backfill has not been studied at length, and no tests are conducted on binders used in backfill for their resistance to attack. Current ASTM guidelines for sulphate attack tests have been deemed inadequate by several authors due to their measurement of only expansion as an indicator of attack. Furthermore, the tests take too long to perform or are restricted to cement mortars only, and not to mixed binders that include pozzolans. Based on these, an accelerated test for sulphate attack was developed in this work through modifying and compiling procedures that had been suggested by different authors. Small cubes of two different binders were fully immersed in daily-monitored sodium sulphate and sulphuric acid solutions for a total of 28 days, after 7 days of accelerated curing at 50°C. In addition, four binders were partially immersed in the same solutions for 8 days for an accelerated attack process. The two procedures were conducted in tandem with leach tests using a mixed solution of

  3. WindoWorks: A flexible program for computerized testing of accelerator control system electronic circuit boards

    Since most accelerator control system circuit boards reside in a commercial bus architecture, such as CAMAC or VMEbus, a computerized test station is needed for exercising the boards. This test station is needed for the development of newly designed prototypes, for commissioning newly manufactured boards, for diagnosing boards which have failed in service, and for long term testing of boards with intermittent failure problems. WindoWorks was created to address these needs. It is a flexible program which runs on a PC compatible computer and uses a PC to bus crate interface. WindoWorks was designed to give the user a flexible way to test circuit boards. Each test is incapsulated into a window. By bringing up several different windows the user can run several different tests simultaneously. The windows are sizable, and moveable. They have data entry boxes so that the test can be customized to the users preference. The windows can be used in conjunction with each other in order to create supertests. There are several windows which are generic. They can be used to test basic functions on any VME (or CAMAC) board. There are other windows which have been created to test specific boards. New windows for testing specific boards can be easily created by a Pascal programmer using the WindoWorks framework

  4. Error-Rate Estimation Based on Multi-Signal Flow Graph Model and Accelerated Radiation Tests.

    He, Wei; Wang, Yueke; Xing, Kefei; Deng, Wei; Zhang, Zelong

    2016-01-01

    A method of evaluating the single-event effect soft-error vulnerability of space instruments before launched has been an active research topic in recent years. In this paper, a multi-signal flow graph model is introduced to analyze the fault diagnosis and meantime to failure (MTTF) for space instruments. A model for the system functional error rate (SFER) is proposed. In addition, an experimental method and accelerated radiation testing system for a signal processing platform based on the field programmable gate array (FPGA) is presented. Based on experimental results of different ions (O, Si, Cl, Ti) under the HI-13 Tandem Accelerator, the SFER of the signal processing platform is approximately 10-3(error/particle/cm2), while the MTTF is approximately 110.7 h. PMID:27583533

  5. Generation of laser pulse trains for tests of multi-pulse laser wakefield acceleration

    Shalloo, R. J.; Corner, L.; Arran, C.; Cowley, J.; Cheung, G.; Thornton, C.; Walczak, R.; Hooker, S. M.

    2016-09-01

    In multi-pulse laser wakefield acceleration (MP-LWFA) a plasma wave is driven by a train of low-energy laser pulses separated by the plasma period, an approach which offers a route to driving plasma accelerators with high efficiency and at high pulse repetition rates using emerging technologies such as fibre and thin-disk lasers. Whilst these laser technologies are in development, proof-of-principle tests of MP-LWFA require a pulse train to be generated from a single, high-energy ultrafast pulse. Here we demonstrate the generation of trains of up to 7 pulses with pulse separations in the range 150-170 fs from single 40 fs pulses produced by a Ti:sapphire laser.

  6. Progress on High Power Tests of Dielectric-Loaded Accelerating Structures

    Jing, Chunguang; Gold, Steven H; Kinkead, Allen; Konecny, Richard; Power, John G

    2005-01-01

    This paper presents a progress report on a series of high-power rf experiments that were carried out to evaluate the potential of the Dielectric-Loaded Accelerating (DLA) structure for high-gradient accelerator operation. Since the last PAC meeting in 2003, we have tested DLA structures loaded with two different ceramic materials: Alumina (Al2O3) and MCT (MgxCa1-xTiO3). The alumina-based DLA experiments have concentrated on the effects of multipactor in the structures under high-power operation, and its suppression using TiN coatings, while the MCT experiments have investigated the dielectric joint breakdown observed in the structures due to local field enhancement. In both cases, physical models have been set up, and the potential engineering solutions are being investigated.

  7. Electron lenses and cooling for the Fermilab Integrable Optics Test Accelerator

    Stancari, G; Lebedev, V; Nagaitsev, S; Prebys, E; Valishev, A

    2015-01-01

    Recently, the study of integrable Hamiltonian systems has led to nonlinear accelerator lattices with one or two transverse invariants and wide stable tune spreads. These lattices may drastically improve the performance of high-intensity machines, providing Landau damping to protect the beam from instabilities, while preserving dynamic aperture. The Integrable Optics Test Accelerator (IOTA) is being built at Fermilab to study these concepts with 150-MeV pencil electron beams (single-particle dynamics) and 2.5-MeV protons (dynamics with self fields). One way to obtain a nonlinear integrable lattice is by using the fields generated by a magnetically confined electron beam (electron lens) overlapping with the circulating beam. The required parameters are similar to the ones of existing devices. In addition, the electron lens will be used in cooling mode to control the brightness of the proton beam and to measure transverse profiles through recombination. More generally, it is of great interest to investigate whet...

  8. Methodology to improve design of accelerated life tests in civil engineering projects.

    Jing Lin

    Full Text Available For reliability testing an Energy Expansion Tree (EET and a companion Energy Function Model (EFM are proposed and described in this paper. Different from conventional approaches, the EET provides a more comprehensive and objective way to systematically identify external energy factors affecting reliability. The EFM introduces energy loss into a traditional Function Model to identify internal energy sources affecting reliability. The combination creates a sound way to enumerate the energies to which a system may be exposed during its lifetime. We input these energies into planning an accelerated life test, a Multi Environment Over Stress Test. The test objective is to discover weak links and interactions among the system and the energies to which it is exposed, and design them out. As an example, the methods are applied to the pipe in subsea pipeline. However, they can be widely used in other civil engineering industries as well. The proposed method is compared with current methods.

  9. High-Gradient test results from a CLIC prototype accelerating structure : TD26CC

    Degiovanni, A; Farabolini, W; Grudiev, A; Kovermann, J; Montessinos, E; Riddone, G; Syratchev, I; Wegner, R; Wuensch, W; Solodko, A; Woolley, B

    2014-01-01

    The CLIC study has progressively tested prototype accelerating structures which incorporate an ever increasing number of features which are needed for a final version ready to be installed in a linear collider. The most recent high power test made in the CERN X-band test stand, Xbox-1, is of a CERN-built prototype which includes damping features but also compact input and output power couplers, which maximize the overall length to active gradient ratio of the structure. The structure’s high-gradient performance, 105 MV/m at 250 ns pulse length and low breakdown rate, matches previously tested structures validating both CERN fabrication and the compact coupler design.

  10. Test of pixel detectors for laser-driven accelerated particle beams

    Laser-driven accelerated (LDA) particle beams have due to the unique acceleration process very special properties. In particular they are created in ultra-short bunches of high intensity exceeding more than 107 (particles)/cm2·ns per bunch. Characterization of these beams is very limited with conventional particle detectors. Non-electronic detectors such as imaging plates or nuclear track detectors are, therefore, conventionally used at present. Moreover, all these detectors give only offline information about the particle pulse position and intensity as they require minutes to hours to be processed, calling for a new highly sensitive online device. Here, we present tests of different pixel detectors for real time detection of LDA ion pulses. Experiments have been performed at the Munich 14MV Tandem accelerator with 8–20 MeV protons in dc and pulsed beam, the latter producing comparable flux as a LDA ion pulse. For detection tests we chose the position-sensitive quantum-counting semiconductor pixel detector Timepix which also provides per-pixel energy- or time-sensitivity. Additionally other types of commercially available pixel detectors are being evaluated such as the RadEye™1, a large area (25 x 50 mm2) CMOS image sensor. All of these devices are able to resolve individual ions with high spatial- and energy-resolution down to the level of μm and tens of keV, respectively. Various beam delivering parameters of the accelerator were thus evaluated and verified. The different readout modes of the Timepix detector which is operated with an integrated USB-based readout interface allow online visualization of single and time-integrated events. Therefore Timepix offers the greatest potential in analyzing the beam parameters.

  11. Testing Einstein's time dilation under acceleration using Mössbauer spectroscopy

    The Einstein time dilation formula was tested in several experiments. Many trials have been conducted to measure the transverse second-order Doppler shift by Mössbauer spectroscopy using a rotating absorber, to test the validity of this formula. Such experiments are also able to test if the time dilation depends only on the velocity of the absorber, as assumed by Einstein's clock hypothesis, or whether the present centripetal acceleration contributes to the time dilation. We show here that because the experiment requires γ-ray emission and detection slits of finite size, the absorption line is broadened, by geometric longitudinal first-order Doppler shifts immensely. Moreover, the absorption line is non-Lorentzian. We obtain an explicit expression for the absorption line for any angular velocity of the absorber. The analysis of the experimental results in all previous experiments which did not observe the full absorption line itself were wrong and the conclusions doubtful. The only proper experiment was done by Kündig (1963 Phys. Rev. 129 2371), who observed the broadening, but associated it with random vibrations of the absorber. We establish necessary conditions for the successful measurement of a transverse second-order Doppler shift by Mössbauer spectroscopy. We indicate how the results of such an experiment can be used to verify the existence of a Doppler shift due to acceleration and to test the validity of Einstein's clock hypothesis. (paper)

  12. A study of erosion in die casting dies by a multiple pin accelerated erosion test

    Shivpuri, R.; Yu, M.; Venkatesan, K.; Chu, Y.-L.

    1995-04-01

    An accelerated erosion test was developed to evaluate the erosion resistance of die materials and coatings for die casting application. An acceleration in wear was achieved by selecting pyramid-shaped core pins, hypereutectic aluminum silicon casting alloy, high melt temperatures and high gate velocities. Multiple pin design was selected to enable multiple test sites for comparative evaluation. Apilot run was conducted on a 300 ton commercial die casting machine at various sites (pins) to verify the thermal and flow similarities. Subsequently, campaigns were run on two different 300 ton commercial die casting machines to evaluate H13 die material and different coatings for erosive resistance. Coatings and surface treatments evaluated included surface micropeening, titanium nitride, boron carbide, vanadium carbide, and metallic coatings—tungsten, molybdenum, and platinum. Recent campaigns with different melt temperatures have indicated a possible link between soldering phenomena and erosive wear. This paper presents the details of the test set up and the results of the pilot and evaluation tests.

  13. 78 FR 60998 - Strategies To Accelerate the Testing and Adoption of Pay for Success (PFS) Financing Models

    2013-10-02

    ... Strategies To Accelerate the Testing and Adoption of Pay for Success (PFS) Financing Models AGENCY: Office of... publicly available on the Internet. FOR FURTHER INFORMATION CONTACT: Cara Camacho by email: cara.camacho... achievement of program outcomes by accelerating adoption of PFS to improve program outcomes. What is...

  14. Experimental high gradient testing of a 17.1 GHz photonic band-gap accelerator structure

    Munroe, Brian J.; Zhang, JieXi; Xu, Haoran; Shapiro, Michael A.; Temkin, Richard J.

    2016-03-01

    We report the design, fabrication, and high gradient testing of a 17.1 GHz photonic band-gap (PBG) accelerator structure. Photonic band-gap (PBG) structures are promising candidates for electron accelerators capable of high-gradient operation because they have the inherent damping of high order modes required to avoid beam breakup instabilities. The 17.1 GHz PBG structure tested was a single cell structure composed of a triangular array of round copper rods of radius 1.45 mm spaced by 8.05 mm. The test assembly consisted of the test PBG cell located between conventional (pillbox) input and output cells, with input power of up to 4 MW from a klystron supplied via a TM01 mode launcher. Breakdown at high gradient was observed by diagnostics including reflected power, downstream and upstream current monitors and visible light emission. The testing procedure was first benchmarked with a conventional disc-loaded waveguide structure, which reached a gradient of 87 MV /m at a breakdown probability of 1.19 ×10-1 per pulse per meter. The PBG structure was tested with 100 ns pulses at gradient levels of less than 90 MV /m in order to limit the surface temperature rise to 120 K. The PBG structure reached up to 89 MV /m at a breakdown probability of 1.09 ×10-1 per pulse per meter. These test results show that a PBG structure can simultaneously operate at high gradients and low breakdown probability, while also providing wakefield damping.

  15. Beam Profile Measurement of 300 kV Ion Source Test Stand for 1 MV Electrostatic Accelerator

    Park, Sae-Hoon; Kim, Yu-Seok [Dongguk University, Gyeonju (Korea, Republic of); Kim, Dae-Il; Kwon, Hyeok-Jung; Cho, Yong-Sub [Korea Multipurpose Accelerator Complex, Gyeongju (Korea, Republic of)

    2015-10-15

    In this paper, RF ion source, test stand of the ion source and its test results are presented. Beam profile was measured at the downstream from the accelerating tube and at the beam dump by using BPM and wire scanner. The RF ion source of the test stand is verified by measuring the total beam current with a faraday cup in the chamber. The KOMAC (KOrea Multi-purpose Accelerator Complex) has been developing a 300 kV ion source test stand for a 1 MV electrostatic accelerator. An ion source and accelerating tube will be installed in a high pressure vessel. The ion source in a high pressure vessel requires high reliability. To confirm the stable operation of the ion source, a test stand was proposed and developed. The ion source will be tested at the test stand to verify its long-term operation conditions. The test stand consists of a 300 kV high voltage terminal, a battery for the ion source power, a 60 Hz inverter, a 200 MHz RF power, a 5 kV extraction power supply, a 300 kV accelerating tube, and a vacuum system. The beam profile monitor was installed at the downstream from the accelerating tube. Wire scanner and faraday-cup was installed at the end of the chamber.

  16. An accelerated step test to assess dancer pre-season aerobic fitness.

    Bronner, Shaw; Rakov, Sara

    2014-03-01

    As the technical performance demands of dance increase, professional companies and pre-professional schools are implementing pre-season screenings that require an efficient, cost effective way to measure dancer aerobic fitness. The aim of this study was to assess an accelerated 3-minute step test (112 beats·min(-1)) by comparing it to the well-studied YMCA step test (96 beats·min(-1)) and a benchmark standard, an incremental treadmill test, using heart rate (HR) and oxygen consumption (VO2) as variables. Twenty-six professional and pre- professional dancers (age 20 ± 2.02 years) were fitted with a telemetric gas analysis system and HR monitor. They were tested in the following order: 96 step, 112 step, and treadmill test, with rest to return to baseline heart rate between each test. The step and treadmill tests were compared using Intra-class Correlation Coefficients [ICC (3, k)] calculated with analysis of variance (p dance populations, though further testing in larger groups of dancers representing a diverse range of genres and training levels is needed. PMID:24568799

  17. Test results of a Nb3Al/Nb3Sn subscale magnet for accelerator application

    The High Energy Accelerator Research Organization (KEK) has been developing a Nb3Al and Nb3Sn subscale magnet to establish the technology for a high-field accelerator magnet. The development goals are a feasibility demonstration for a Nb3Al cable and the technology acquisition of magnet fabrication with Nb3Al superconductors. KEK developed two double-pancake racetrack coils with Rutherford-type cables composed of 28 Nb3Al wires processed by rapid heating, quenching, and transformation in collaboration with the National Institute for Materials Science and the Fermi National Accelerator Laboratory. The magnet was fabricated to efficiently generate a high magnetic field in a minimum-gap common-coil configuration with two Nb3Al coils sandwiched between two Nb3Sn coils produced by the Lawrence Berkeley National Laboratory. A shell-based structure and a 'bladder and key' technique have been used for adjusting coil prestress during both the magnet assembly and the cool down. In the first excitation test of the magnet at 4.5 K performed in June 2014, the highest quench current of the Nb3Sn coil, i.e., 9667 A, was reached at 40 A/s corresponding to 9.0 T in the Nb3Sn coil and 8.2 T in the Nb3Al coil. The quench characteristics of the magnet were studied

  18. The Conversion of CESR to Operate as the Test Accelerator, CesrTA, Part 4: Superconducting Wiggler Diagnostics

    Billing, M G; Liu, X; Li, Y; Sabol, D; Smith, E N; Strohman, C R; Palmer, M A; Munson, D V

    2016-01-01

    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 appropriate 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, the last in a series of four, describes the vacuum system modifications of the superconducting wigglers to accommodate the diagnostic instrumentation for the study of electron cloud (EC) behavior within wigglers. Earlier papers provided an overview of the accelerator physics program, the general modifications of CESR, the modifications of the vacuum system necessary for the conversion of CESR to the test accelerator, CesrTA, enhanced to study such ...

  19. Electrical Testing of Cement-Based Materials: Role of Testing Techniques, Sample Conditioning, and Accelerated Curing

    Spragg, Robert; Bu, Yiwen; Snyder, Kenneth; Bentz, Dale; Weiss, Jason

    2013-01-01

    These projects examined the potential for using electrical testing on concrete as a potential surrogate for obtaining information on ion and fluid transport. Electrical measurements are particularly attractive for use in quality control as they are easy to perform, are performed rapidly, and can be directly related to fluid transport. This work describes how electrical resistance measurements should be corrected for geometry to obtain a geometry independent resistivity or conductivity. Furthe...

  20. Long-term storage life of light source modules by temperature cycling accelerated life test

    Light source modules are the most crucial and fragile devices that affect the life and reliability of the interferometric fiber optic gyroscope (IFOG). While the light emitting chips were stable in most cases, the module packaging proved to be less satisfactory. In long-term storage or the working environment, the ambient temperature changes constantly and thus the packaging and coupling performance of light source modules are more likely to degrade slowly due to different materials with different coefficients of thermal expansion in the bonding interface. A constant temperature accelerated life test cannot evaluate the impact of temperature variation on the performance of a module package, so the temperature cycling accelerated life test was studied. The main failure mechanism affecting light source modules is package failure due to solder fatigue failure including a fiber coupling shift, loss of cooling efficiency and thermal resistor degradation, so the Norris-Landzberg model was used to model solder fatigue life and determine the activation energy related to solder fatigue failure mechanism. By analyzing the test data, activation energy was determined and then the mean life of light source modules in different storage environments with a continuously changing temperature was simulated, which has provided direct reference data for the storage life prediction of IFOG. (semiconductor devices)

  1. Simulation and steering in the intertank matching section of the ground test accelerator

    The Intertank Matching Section (IMS) of the Ground Test Accelerator (GTA) is a short (36 cm) beamline designed to match the Radio Frequency Quadrupole (RFQ) exit beam into the first Drift Tube LINAC (DTL) tank. The IMS contains two steering quadrupoles (SMQs) and four variable-field focussing quads (VFQs). The SMQs are fixed strength permanent magnet quadrupoles on mechanical actuators capable of transverse movement for the purpose of steering the beam. The upstream and downstream steering quadrupoles are labelled SMQ1 and SMQ4 respectively. Also contained in the IMS are two RF cavities for longitudinal matching

  2. Using a Tandem Pelletron accelerator to produce a thermal neutron beam for detector testing purposes.

    Irazola, L; Praena, J; Fernández, B; Macías, M; Bedogni, R; Terrón, J A; Sánchez-Nieto, B; Arias de Saavedra, F; Porras, I; Sánchez-Doblado, F

    2016-01-01

    Active thermal neutron detectors are used in a wide range of measuring devices in medicine, industry and research. For many applications, the long-term stability of these devices is crucial, so that very well controlled neutron fields are needed to perform calibrations and repeatability tests. A way to achieve such reference neutron fields, relying on a 3 MV Tandem Pelletron accelerator available at the CNA (Seville, Spain), is reported here. This paper shows thermal neutron field production and reproducibility characteristics over few days. PMID:26595777

  3. Instrumentation and control system for the AT-2 accelerator test stand

    A data-driven subroutine package, written for our accelerator test stand (ATS), is described. This flexible package permits the rapid writing and modifying of data acquisition, control, and analysis programs for the many diverse experiments performed on the ATS. These structurally simple and easy to maintain routines help to control administratively the integrity of the ATS through the use of the database. Our operating experience indicates that the original design goals have been met. We describe the subroutines, database, and our experiences with this system

  4. Design, fabrication and testing of a large cylindrical vacuum vessel for proton linear accelerator

    The paper deals with engineering design, fabrication, copper plating and vacuum design and leak testing of the first prototype segment of Alveraz type drift tube Proton Linear Accelerator (DTL) being developed at CAT. The prototype drift tube linac segment is a long horizontal cylindrical vacuum vessel. The cylindrical cavity is internally machined and copper plated from inside and operates at 202 MHz (RF) with a vacuum better than 1 x 10-6 mbar. There are 34 openings provided for vacuum pumps, RF input and monitoring loops, piston tuners etc. and a large openings for insertions of drift tubes from top of the tank. (author)

  5. Constant-Step Stress Accelerated Life Test of VFD under Logarithmic Normal Distribution Case

    2006-01-01

    In order to solve the life problem of vacuum fluorescent display (VFD) within shorter time, and reduce the life prediction cost, a constant-step stress accelerated life test was performed with its cathode temperature increased. Statistical analysis was done by applying logarithmic normal distribution for describing the life, and least square method (LSM) for estimating logarithmic normal parameters. Self-designed special software was used to predict the VFD life. It is verified by numerical results that the VFD life follows logarithmic normal distribution,and that the life-stress relationship satisfies linear Arrhenius equation completely. The accurate calculation of the key parameters enables the rapid estimation of VFD life.

  6. Constant-step stress accelerated life test of VFD under Weibull distribution case

    ZHANG Jian-ping; GENG Xin-min

    2005-01-01

    Constant-step stress accelerated life test of Vacuum Fluorescent Display (VFD) was conducted with increased cathode temperature. Statistical analysis was done by applying Weibull distribution for describing the life, and Least Square Method (LSM)for estimating Weibull parameters. Self-designed special software was used to predict the VFD life. Numerical results showed that the average life of VFD is over 30000 h, that the VFD life follows Weibull distribution, and that the life-stress relationship satisfies linear Arrhenius equation completely. Accurate calculation of the key parameter enabled rapid estimation of VFD life.

  7. Accelerated leaching of cementitious materials using ammonium nitrate (6 M): influence of test conditions

    We have focused on the test conditions influence on accelerated degradation of cementitious materials using ammonium nitrate. PH-buffering and renewal of the leaching solution were studied. PH-buffering appeared not to be very important when the renewal pH remains under eight. Renewal appeared to be the most influential feature. Its absence leads to calcium accumulation in the leaching solution inducing aggressiveness fall. Degradation is then less marked in terms of depth, flux and mineralogy. The resulting porosity increase is also smaller. (authors)

  8. Laserwire at the Accelerator Test Facility 2 with Sub-Micrometre Resolution

    Nevay, L. J.; Boogert, S.T.; Karataev, P.; Kruchinin, K.; Corner, L; Howell, D. F.; Walczak, R.; Aryshev, A.; Urakawa, J.; Terunuma, N.

    2014-01-01

    A laserwire transverse electron beam size measurement system has been developed and operated at the Accelerator Test Facility 2 (ATF2) at KEK. Special electron beam optics were developed to create an approximately 1 x 100 {\\mu}m (vertical x horizontal) electron beam at the laserwire location, which was profiled using a 150 mJ, 71 ps laser pulse with a wavelength of 532 nm. The precise characterisation of the laser propagation allows the non-Gaussian transverse profiles of the electron beam ca...

  9. An experimental test of Newton's law of gravitation for small accelerations

    Schubert, Sven

    2011-10-15

    The experiment presented in this thesis has been designed to test Newton's law of gravitation in the limit of small accelerations caused by weak gravitational forces. It is located at DESY, Hamburg, and is a modification of an experiment that was carried out in Wuppertal, Germany, until 2002 in order to measure the gravitational constant G. The idea of testing Newton's law in the case of small accelerations emerged from the question whether the flat rotation curves of spiral galaxies can be traced back to Dark Matter or to a law of gravitation that deviates from Newton on cosmic scales like e.g. MOND (Modified Newtonian Dynamics). The core of this experiment is a microwave resonator which is formed by two spherical concave mirrors that are suspended as pendulums. Masses between 1 and 9 kg symmetrically change their distance to the mirrors from far to near positions. Due to the increased gravitational force the mirrors are pulled apart and the length of the resonator increases. This causes a shift of the resonance frequency which can be translated into a shift of the mirror distance. The small masses are sources of weak gravitational forces and cause accelerations on the mirrors of about 10{sup -10} m/s{sup 2}. These forces are comparable to those between stars on cosmic scales and the accelerations are in the vicinity of the characteristic acceleration of MOND a{sub 0} {approx} 1.2.10{sup -10} m/s{sup 2}, where deviations from Newton's law are expected. Thus Newton's law could be directly checked for correctness under these conditions. First measurements show that due to the sensitivity of this experiment many systematic influences have to be accounted for in order to get consistent results. Newton's law has been confirmed with an accuracy of 3%. MOND has also been checked. In order to be able to distinguish Newton from MOND with other interpolation functions the accuracy of the experiment has to be improved. (orig.)

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

    Hutton, Andrew [TJNAF; Areti, Hari [TJNAF

    2015-03-05

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

  11. Tolerable Limits of Oscillatory Accelerations Due to Rolling Motions Experienced by One Pilot During Automatic-Interceptor Flight Tests

    Brissenden, Roy F.; Cheatham, Donald C.; Champine, Robert A.

    1961-01-01

    Limited flight - test data obtained from an automatically controlled interceptor during runs in which oscillatory rolling motions were encountered have been correlated with the pilot's comments regarding his ability to tolerate the imposed lateral accelerations.

  12. Accelerated Degradation Test and Predictive Failure Analysis of B10 Copper-Nickel Alloy under Marine Environmental Conditions

    Bo Sun; Tianyuan Ye; Qiang Feng; Jinghua Yao; Mumeng Wei

    2015-01-01

    This paper studies the corrosion behavior of B10 copper-nickel alloy in marine environment. Accelerated degradation test under marine environmental conditions was designed and performed based on the accelerated testing principle and the corrosion degradation mechanism. With the prolongation of marine corrosion time, the thickness of Cu2O film increased gradually. Its corrosion product was Cu2(OH)3Cl, which increased in quantity over time. Cl− was the major factor responsible for the marine c...

  13. High power testing of the multiple-loop radio-frequency drive concept for the FMIT accelerator

    The Fusion Materials Irradiation Test (FMIT) accelerator requires several 600-kW rf systems to simultaneously supply rf power to a single accelerator tank. Each rf-system output must be carefully phase and amplitude controlled to achieve the proper system performance. Two 80-MHz, 600-kW rf amplifiers with phase- and amplitude-control systems have been tested into a single, high-Q resonant cavity. Experimental results are presented

  14. Application of the EXPERT consultation system to accelerated laboratory testing and interpretation.

    Van Lente, F; Castellani, W; Chou, D; Matzen, R N; Galen, R S

    1986-09-01

    The EXPERT consultation system-building tool, a knowledge-based artificial intelligence program developed at Rutgers University, has been applied to the development of a laboratory consultation system facilitating sequential laboratory testing and interpretation. Depending on the results of a basic panel of laboratory tests, the system requests that specific secondary tests be performed. Input of these secondary findings can result in requests for tertiary testing, to complete the database necessary for interpretation. Interpretation of all results is based upon final inferences from the collected findings through a series of rules, a hierarchical network that yields an efficient production system not easily obtained through conventional programming. The rules included in this model are based upon initial results for total protein, calcium, glucose, total bilirubin, alkaline phosphatase, lactate dehydrogenase, aspartate aminotransferase, thyroxin, hemoglobin, mean corpuscular volume, and the concentrations of four drugs. Pertinent clinical history items included are jaundice, diabetes, thyroid disease, medications, and ethanol. Implementing this system in a laboratory-based accelerated testing program involving outpatients maximized the effective use of laboratory resources, eliminated useless testing, and provided the patient with low-cost laboratory information. PMID:3527478

  15. Lessons from two field tests on pipeline damage detection using acceleration measurement

    Shinozuka, Masanobu; Lee, Sungchil; Kim, Sehwan; Chou, Pai H.

    2011-04-01

    Early detection of pipeline damages has been highlighted in water supply industry. Water pressure change in pipeline due to a sudden rupture causes pipe to vibrate and the pressure change propagates through the pipeline. From the measurement of pipe vibration the rupture can be detected. In this paper, the field test results and observations are provided for implementing next generation of SCADA system for pipeline rupture detection. Two field tests were performed on real buried plastic and metal pipelines for rupture detection. The rupture was simulated by introducing sudden water pressure drop caused by water blow-off and valve control. The measured acceleration data at the pipe surfaces were analyzed in both time and frequency domain. In time domain, the sudden narrow increase of acceleration amplitude was used as an indication of rupture event. For the frequency domain analysis, correlation function and the short time Fourier Transform technique were adopted to trace the dominant frequency shift. The success of rupture detection was found to be dependent on several factors. From the frequency analysis, the dominant frequency of metal water pipe was shifted by the water pressure drop, however, it was hard to identify from the plastic pipeline. Also the influence of existing facility such as airvac on pipe vibrations was observed. Finally, several critical lessons learned in the viewpoint of field measurement are discussed in this paper.

  16. Performance testing of the LUEhR-40M structure with an accelerated beam

    The results of experimental investigation of the prototype of the accelerating structure of the therapeutic linear accelerator of the LUEhR-40M model with an accelerating beam are presented. The accelerating structure is the standing wave biperiodic structure with inner coupling cells of 1.6 m length. The design energy of accelerated electrons equalling 20 MeV (during single electron beam passage through an accelerating structure) is obtained. 60 % of accelerated particles are accumulated in the energy interval of (20±1) MeV at 20 mA pulse current and at 3.6 MW SHF-power at the structure input

  17. Accelerated gravity testing of aquitard core permeability and implications at formation and regional scale

    Timms, W. A.; Crane, R.; Anderson, D. J.; Bouzalakos, S.; Whelan, M.; McGeeney, D.; Rahman, P. F.; Acworth, R. I.

    2016-01-01

    Evaluating the possibility of leakage through low-permeability geological strata is critically important for sustainable water supplies, the extraction of fuels from coal and other strata, and the confinement of waste within the earth. The current work demonstrates that relatively rapid and realistic vertical hydraulic conductivity (Kv) measurements of aquitard cores using accelerated gravity can constrain and compliment larger-scale assessments of hydraulic connectivity. Steady-state fluid velocity through a low-K porous sample is linearly related to accelerated gravity (g level) in a centrifuge permeameter (CP) unless consolidation or geochemical reactions occur. A CP module was custom designed to fit a standard 2 m diameter geotechnical centrifuge (550 g maximum) with a capacity for sample dimensions up to 100 mm diameter and 200 mm length, and a total stress of ˜ 2 MPa at the base of the core. Formation fluids were used as influent to limit any shrink-swell phenomena, which may alter the permeability. Kv results from CP testing of minimally disturbed cores from three sites within a clayey-silt formation varied from 10-10 to 10-7 m s-1 (number of samples, n = 18). Additional tests were focussed on the Cattle Lane (CL) site, where Kv within the 99 % confidence interval (n = 9) was 1.1 × 10-9 to 2.0 × 10-9 m s-1. These Kv results were very similar to an independent in situ Kv method based on pore pressure propagation though the sequence. However, there was less certainty at two other core sites due to limited and variable Kv data. Blind standard 1 g column tests underestimated Kv compared to CP and in situ Kv data, possibly due to deionised water interactions with clay, and were more time-consuming than CP tests. Our Kv results were compared with the set-up of a flow model for the region, and considered in the context of heterogeneity and preferential flow paths at site and formation scale. Reasonable assessments of leakage and solute transport through

  18. Accelerated atmospheric corrosion testing using a cyclic wet/dry exposure test

    Aluminum corrosion is important in overhead electrical conductors constructed from aluminum wire centrally reinforced by galvanized steel strands. Inspection of conductor after long service has implicated rubber bushing material, on the outside, and the galvanized strands, on the inside, as providing potential galvanic sites for the initiation of rapid aluminum corrosion. Therefore, the galvanic corrosion of aluminum in contact with graphite-loaded neoprene rubber, hot-dip galvanized steel and steel was assessed in a cyclic wet/dry exposure test using mixed-salts spray solutions containing appropriate ratios of sulfate and chloride ion. Aluminum was found to corrode at between 3 to 6 times its uncoupled rate when associated with the rubber material. While the eta-phase, relatively pure Zn, galvanized layer remained intact, galvanic corrosion of aluminum was slow. However, on exposure of the zeta-phase, Zn/Fe intermetallic layer, aluminum corroded about 35 times faster than expected in a solution with a high level of Cl- ion. The importance of these data to conductor lifetime is discussed

  19. Effects of UV on power degradation of photovoltaic modules in combined acceleration tests

    Ngo, Trang; Heta, Yushi; Doi, Takuya; Masuda, Atsushi

    2016-05-01

    UV exposure and other factors such as high/low temperature, humidity and mechanical stress have been reported to degrade photovoltaic (PV) module materials. By focusing on the combined effects of UV stress and moisture on PV modules, two new acceleration tests of light irradiation and damp heat (DH) were designed and conducted. The effects of UV exposure were validated through a change in irradiation time (UV dosage) and a change of the light irradiation side (glass side vs backsheet side) in the UV-preconditioned DH and cyclic sequential tests, respectively. The chemical corrosion of finger electrodes in the presence of acetic acid generated from ethylene vinyl acetate used as an encapsulant was considered to be the main origin of degradation. The module performance characterized by electroluminescence images was confirmed to correlate with the measured acetic acid concentration and Ag finger electrode resistance.

  20. Evaluation of Dynamic Mechanical Loading as an Accelerated Test Method for Ribbon Fatigue: Preprint

    Bosco, N.; Silverman, T. J.; Wohlgemuth, J.; Kurtz, S.; Inoue, M.; Sakurai, K.; Shinoda, T.; Zenkoh, H.; Hirota, K.; Miyashita, M.; Tadanori, T.; Suzuki, S.

    2015-04-07

    Dynamic Mechanical Loading (DML) of photovoltaic modules is explored as a route to quickly fatigue copper interconnect ribbons. Results indicate that most of the interconnect ribbons may be strained through module mechanical loading to a level that will result in failure in a few hundred to thousands of cycles. Considering the speed at which DML may be applied, this translates into a few hours o testing. To evaluate the equivalence of DML to thermal cycling, parallel tests were conducted with thermal cycling. Preliminary analysis suggests that one +/-1 kPa DML cycle is roughly equivalent to one standard accelerated thermal cycle and approximately 175 of these cycles are equivalent to a 25-year exposure in Golden Colorado for the mechanism of module ribbon fatigue.

  1. ASSESSMENT OF THE PCFBC-EXPOSED AND ACCELERATED LIFE-TESTED CANDLE FILTERS; TOPICAL

    Development of the hot gas filtration technology has been the focus of DOE/FETC and Siemens Westinghouse Power Corporation during the past twenty years. Systems development during this time has successfully lead to the generation and implementation of high temperature Siemens Westinghouse particulate filtration systems that are currently installed and are operational at Demonstration Plant sites, and which are ready for installation at commercial plant sites. Concurrently, materials development has advanced the use of commercially available oxide- and nonoxide-based monoliths, and has fostered the manufacture and use of second generation, oxide-based, continuous fiber reinforced ceramic composites and filament wound materials. This report summarizes the material characterization results for commercially available and second generation filter materials tested in Siemens Westinghouse's advanced, high temperature, particulate removal system at the Foster Wheeler, pressurized circulating fluidized-bed combustion, pilot-scale test facility in Karhula, Finland, and subsequent extended accelerated life testing of aged elements in Siemens Westinghouse pressurized fluidized-bed combustion simulator test facility in Pittsburgh, PA. The viability of operating candle filters successfully for over 1 year of service life has been shown in these efforts. Continued testing to demonstrate the feasibility of acquiring three years of service operation on aged filter elements is recommended

  2. SwissFEL injector conceptual design report. Accelerator test facility for SwissFEL

    This comprehensive report issued by the Paul Scherrer Institute (PSI) in Switzerland takes a look at the design concepts behind the institute's SwissFEL X-ray Laser facility - in particular concerning the conceptual design of the injector system. The SwissFEL X-ray FEL project at PSI, involves the development of an injector complex that enables operation of a FEL system operating at 0.1 - 7 nm with permanent-magnet undulator technology and minimum beam energy. The injector pre-project was motivated by the challenging electron beam requirements necessary to drive the SwissFEL accelerator facility. The report takes a look at the mission of the test facility and its performance goals. The accelerator layout and the electron source are described, as are the low-level radio-frequency power systems and the synchronisation concept. The general strategy for beam diagnostics is introduced. Low energy electron beam diagnostics, the linear accelerator (Linac) and bunch compressor diagnostics are discussed, as are high-energy electron beam diagnostics. Wavelength selection for the laser system and UV pulse shaping are discussed. The laser room for the SwissFEL Injector and constructional concepts such as the girder system and alignment concepts involved are looked at. A further chapter deals with beam dynamics, simulated performance and injector optimisation. The facility's commissioning and operation program is examined, as are operating regimes, software applications and data storage. The control system structure and architecture is discussed and special subsystems are described. Radiation safety, protection systems and shielding calculations are presented and the lateral shielding of the silo roof examined

  3. Test setup for accelerated test of high power IGBT modules with online monitoring of Vce and Vf voltage during converter operation

    de Vega, Angel Ruiz; Ghimire, Pramod; Pedersen, Kristian Bonderup;

    2014-01-01

    Several accelerated test methods exist in order to study the failures mechanisms of the high power IGBT modules like temperature cycling test or power cycles based on DC current pulses. The main drawback is that the test conditions do not represent the real performance and stress conditions of th...

  4. On the compressibility effect in test particle acceleration by magnetohydrodynamic turbulence

    González, C. A.; Dmitruk, P.; Mininni, P. D.; Matthaeus, W. H.

    2016-08-01

    The effect of compressibility in a charged particle energization by magnetohydrodynamic (MHD) fields is studied in the context of test particle simulations. This problem is relevant to the solar wind and the solar corona due to the compressible nature of the flow in those astrophysical scenarios. We consider turbulent electromagnetic fields obtained from direct numerical simulations of the MHD equations with a strong background magnetic field. In order to explore the flow compressibility effect over the particle dynamics, we performed different numerical experiments: an incompressible case and two weak compressible cases with Mach number M = 0.1 and M = 0.25. We analyze the behavior of protons and electrons in those turbulent fields, which are well known to form aligned current sheets in the direction of the guide magnetic field. What we call protons and electrons are test particles with scales comparable to (for protons) and much smaller than (for electrons) the dissipative scale of MHD turbulence, maintaining the correct mass ratio m e / m i . For these test particles, we show that compressibility enhances the efficiency of proton acceleration, and that the energization is caused by perpendicular electric fields generated between currents sheets. On the other hand, electrons remain magnetized and display an almost adiabatic motion, with no effect of compressibility observed. Another set of numerical experiments takes into account two fluid modifications, namely, electric field due to Hall effect and electron pressure gradient. We show that the electron pressure has an important contribution to electron acceleration allowing highly parallel energization. In contrast, no significant effect of these additional terms is observed for the protons.

  5. The Cornell-BNL FFAG-ERL Test Accelerator: White Paper

    Bazarov, Ivan; Dunham, Bruce; Hoffstaetter, Georg; Mayes, Christopher; Patterson, Ritchie; Sagan, David; Ben-Zvi, Ilan; Berg, Scott; Blaskiewicz, Michael; Brooks, Stephen; Brown, Kevin; Fischer, Wolfram; Hao, Yue; Meng, Wuzheng; Méot, François; Minty, Michiko; Peggs, Stephen; Ptitsin, Vadim; Roser, Thomas; Thieberger, Peter; Trbojevic, Dejan; Tsoupas, Nick

    2015-01-01

    The Cornell-BNL FFAG-ERL Test Accelerator (C$\\beta$) will comprise the first ever Energy Recovery Linac (ERL) based on a Fixed Field Alternating Gradient (FFAG) lattice. In particular, we plan to use a Non Scaling FFAG (NS-FFAG) lattice that is very compact and thus space- and cost- effective, enabling multiple passes of the electron beam in a single recirculation beam line, using the superconducting RF (SRF) linac multiple times. The FFAG-ERL moves the cost optimized linac and recirculation lattice to a dramatically better optimum. The prime accelerator science motivation for C$\\beta$ is proving that the FFAG-ERL concept works. This is an important milestone for the Brookhaven National Laboratory (BNL) plans to build a major Nuclear Physics facility, eRHIC, based on producing 21 GeV electron beams to collide with the RHIC ion beams. A consequence of the C$\\beta$ work would be the availability of significantly better, cost-effective, compact CW high-brightness electron beams for a plethora of scientific inves...

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

    Kafka, Gene [Illinois Inst. of Technology, Chicago, IL (United States)

    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.

  7. Los Alamos transmutation research: heavy liquid metal coolant technology and accelerator-driven materials test station

    The US Department of Energy is developing technologies needed to reduce the quantity of high-level nuclear waste bound for deep geologic disposal. Los Alamos National Laboratory has a long history of transmutation research in support of this mission. This report summarises two research programmes in the portfolio development of lead-alloy coolant technology and materials, and the Materials Test Station (MTS) using an accelerator-driven spallation target. We have been developing lead and lead-bismuth coolant technology and materials for advanced transmutation and nuclear energy systems since the mid-1990. Our programme mainly consists of operating a medium-scale lead-bismuth eutectic materials and thermal-hydraulic test loop (DELTA), conducting tests and experiments, developing associated coolant chemistry and liquid metal flow measurement and control sensors, instrumentation and systems, building and validating system corrosion models. We are also building a high-temperature natural convection lead test loop using an advanced material (Al-rich oxide dispersion strengthened steel). Key activities and an assessment of the technological readiness level will be given. (authors)

  8. Allowance for insulation aging in the new concept of accelerated life tests of high-voltage power transformers

    This paper reports that the existing system of type and acceptance tests of high-voltage transformer insulation does not take into account insulation ageing, which is particularly objectionable with respect to equip-met with reduced insulation levels. Suggested in the paper is a new concept of accelerated life tests based on integrated simulation of basic operating loads, both periodic (surge) and long-term ones; by making a long-term accelerated test simulating the working conditions, with exposure of test object and/or its insulation to periodic operating surges (overvoltages and overcurrents). This test replaces a group of conventional individual acceptance tests and provides more ample and more precise information on performance and dependability of the equipment. The test procedure was checked in test of a small lot of 1600 kVA 35 kV power transformers

  9. ADS-Lib/V1.0. A test library for Accelerator Driven Systems. Summary documentation

    The report describes the generation of a test library for a number of code systems used in the analysis of Accelerator Driven Systems (ADS). The generation of the ADS library was undertaken by IAEA-NDS and the data files are available to users at http://wwwnds. iaea.org/ads/ and also as CD-ROM (upon request).The source of the evaluated nuclear data was the JEFF-3.1 library. Processing was carried out using NJOY-99.90 with the local updates at IAEA-NDS. The resulting processed files are available in ACE format for MCNP and in MATXS format for multi-group transport calculations. (author)

  10. Test of new accelerator superconducting dipoles suitable for high precision field

    Field homogeneity of superconducting dipoles for accelerators is still difficult to achieve. To reach the required homogeneity level of 10-4 the conductors must be located within a few hundreths of mm. At present all the superconducting machines in construction or in project use the most developed technique of the double shell configuration. This technique is very sensitive to conductor size and a great care must be taken to reach the needed field homogeneity. The design proposed in this paper is a current block configuration which uses accuratly punched laminations with slots for conductor location. The design is then much less sensitive to conductor size. Furthermore the tooling needed to build such magnets is much less expensive than the one needed for the shell design. Three short dipoles have been constructed and tested. Very good results in field homogeneity have been obtained directly from the original design

  11. Design of CEBAF's [Continuous Electron Beam Accelerator Facility] rf separator and results of cold tests

    The design of the CEBAF accelerator system is based upon a multipass racetrack configuration, the straight sections of which will utilize 1497-MHz superconducting linac sections with independent magnetic transport at the end of each linac segment. Room temperature SW rf separators operating at a frequency of 998 MHz will be used in each independent transport channel at one end of the racetrack to extract a portion of the recirculating current. With the frequency chosen and appropriate phasing, three independent beams of correlated energy may be extracted for use in the three experimental areas. The design of the rf separators, abased on an alternating periodic structure (APS), will be described and some preliminary prototype cold test results will be given. 11 refs., 10 figs., 2 tabs

  12. Cavity beam position monitor system for the Accelerator Test Facility 2

    Kim, Y I; Aryshev, A; Boogert, S T; Boorman, G; Frisch, J; Heo, A; Honda, Y; Hwang, W H; Huang, J Y; Kim, E -S; Kim, S H; Lyapin, A; Naito, T; May, J; McCormick, D; Mellor, R E; Molloy, S; Nelson, J; Park, S J; Park, Y J; Ross, M; Shin, S; Swinson, C; Smith, T; Terunuma, N; Tauchi, T; Urakawa, J; White, G R

    2013-01-01

    The Accelerator Test Facility 2 (ATF2) is a scaled demonstrator system for final focus beam lines of linear high energy colliders. This paper describes the high resolution cavity beam position monitor (BPM) system, which is a part of the ATF2 diagnostics. Two types of cavity BPMs are used, C-band operating at 6.423 GHz, and S-band at 2.888 GHz with an increased beam aperture. The cavities, electronics, and digital processing are described. The resolution of the C-band system with attenuators was determined to be approximately 250 nm and 1 m for the S-band system. Without attenuation the best recorded C-band cavity resolution was 27 nm.

  13. Final safety analysis report for the Ground Test Accelerator (GTA), Phase 2

    NONE

    1994-10-01

    This document is the first volume of a 3 volume safety analysis report on the Ground Test Accelerator (GTA). The GTA program at the Los Alamos National Laboratory (LANL) is the major element of the national Neutral Particle Beam (NPB) program, which is supported by the Strategic Defense Initiative Office (SDIO). A principal goal of the national NPB program is to assess the feasibility of using hydrogen and deuterium neutral particle beams outside the Earth`s atmosphere. The main effort of the NPB program at Los Alamos concentrates on developing the GTA. The GTA is classified as a low-hazard facility, except for the cryogenic-cooling system, which is classified as a moderate-hazard facility. This volume consists of an introduction, summary/conclusion, site description and assessment, description of facility, and description of operation.

  14. Accelerated testing of metal foil tape joints and their effect of photovoltaic module reliability

    Sorensen, N. Robert; Quintana, Michael A.; Puskar, Joseph D.; Lucero, Samuel J.

    2009-08-01

    A program is underway at Sandia National Laboratories to predict long-term reliability of photovoltaic (PV) systems. The vehicle for the reliability predictions is a Reliability Block Diagram (RBD), which models system behavior. Because this model is based mainly on field failure and repair times, it can be used to predict current reliability, but it cannot currently be used to accurately predict lifetime. In order to be truly predictive, physics-informed degradation processes and failure mechanisms need to be included in the model. This paper describes accelerated life testing of metal foil tapes used in thin-film PV modules, and how tape joint degradation, a possible failure mode, can be incorporated into the model.

  15. On the Use of Accelerated Test Methods for Characterization of Advanced Composite Materials

    Gates, Thomas S.

    2003-01-01

    A rational approach to the problem of accelerated testing for material characterization of advanced polymer matrix composites is discussed. The experimental and analytical methods provided should be viewed as a set of tools useful in the screening of material systems for long-term engineering properties in aerospace applications. Consideration is given to long-term exposure in extreme environments that include elevated temperature, reduced temperature, moisture, oxygen, and mechanical load. Analytical formulations useful for predictive models that are based on the principles of time-based superposition are presented. The need for reproducible mechanisms, indicator properties, and real-time data are outlined as well as the methodologies for determining specific aging mechanisms.

  16. On the compressibility effect in test particle acceleration by magnetohydrodynamic turbulence

    González, C A; Mininni, P D; Matthaeus, W H

    2016-01-01

    The effect of compressibility in charged particle energization by magnetohydrodynamic (MHD) fields is studied in the context of test particle simulations. This problem is relevant to the solar wind and the solar corona due to the compressible nature of the flow in those astrophysical scenarios. We consider turbulent electromagnetic fields obtained from direct numerical simulations of the MHD equations with a strong background magnetic field. In order to explore the compressibilty effect over the particle dynamics we performed different numerical experiments: an incompressible case, and two weak compressible cases with Mach number M = 0.1 and M = 0.25. We analyze the behavior of protons and electrons in those turbulent fields, which are well known to form aligned current sheets in the direction of the guide magnetic field. We show that compressibility enhances the efficiency of proton acceleration, and that the energization is caused by perpendicular electric fields generated between currents sheets. On the ot...

  17. Final safety analysis report for the Ground Test Accelerator (GTA), Phase 2

    NONE

    1994-10-01

    This document is the third volume of a 3 volume safety analysis report on the Ground Test Accelerator (GTA). The GTA program at the Los Alamos National Laboratory (LANL) is the major element of the national Neutral Particle Beam (NPB) program, which is supported by the Strategic Defense Initiative Office (SDIO). A principal goal of the national NPB program is to assess the feasibility of using hydrogen and deuterium neutral particle beams outside the Earth`s atmosphere. The main effort of the NPB program at Los Alamos concentrates on developing the GTA. The GTA is classified as a low-hazard facility, except for the cryogenic-cooling system, which is classified as a moderate-hazard facility. This volume consists of appendices C through U of the report

  18. Extremely low vertical-emittance beam in accelerator-test facility at KEK

    Electron beams with the lowest, normalized transverse emittance recorded so far were produced and confirmed in single-bunch-mode operation of the Accelerator Test Facility at KEK. We established a tuning method of the damping rings which achieves a small vertical dispersion and small x-y orbit coupling. The vertical emittance was less than 1 percent of the horizontal emittance. At the zero-intensity limit, the vertical normalized emittance was less than 2.8 x 10-8 rad m at beam energy 1.3 GeV. At high intensity, strong effects of intrabeam scattering were observed, which had been expected in view of the extremely high particle density due to the small transverse emittance

  19. Accelerated lifetime testing methodology for lifetime estimation of Lithium-ion batteries used in augmented wind power plants

    Stroe, Daniel Ioan; Swierczynski, Maciej Jozef; Stan, Ana-Irina;

    2013-01-01

    The development of lifetime estimation models for Lithium-ion battery cells, which are working under highly variable mission profiles characteristic for wind power plant applications, requires a lot of expenditures and time resources. Therefore, batteries have to be tested under accelerated...... lifetime ageing conditions. This paper presents a three-stage methodology used for accelerated lifetime testing of Lithium-ion batteries. The results obtained at the end of the accelerated ageing process can be used for the parametrization of a performance-degradation lifetime model. In the proposed...... methodology both calendar and cycling lifetime tests are considered since both components are influencing the lifetime of Lithium-ion batteries. The methodology proposes also a lifetime model verification stage, where Lithium-ion battery cells are tested at normal operating conditions using an application...

  20. Design, testing and modifications of the Pelletron accelerator and future uses

    Solutions to various problems in the design of high voltage generator and acceleration units of the Pelletron electron accelerator designed and constructed at ININ are presented. Information on the design of the control system of the electron beams, activities proposed for utilization of sulfur hexafluoride as an accelerator isolating gas as well as some future uses of the Pelletron. (Author). 7 refs, 3 figs

  1. Development of an accelerated test design for predicting the service life of the solar array at Mead, Nebraska

    Gaines, G.B.; Thomas, R.E.; Noel, G.T.; Shilliday, T.S.; Wood, V.E.; Carmichael, D.C.

    1979-06-07

    This report describes an accelerated test which is designed to predict the life of the 25-kW photovoltaic array installed near Mead, Nebraska. Emphasis is placed on the power-output degradation at the module level and on long-term degradation modes, as appropriate for life prediction of mature devices for which infant failures are few. A quantitative model for accelerating testing using multiple environmental stresses is used to develop the test design. The model accounts for the effects of thermal stress by a relation of the Arrhenius form. This relation is then corrected for the effects of nonthermal environmental stresses such as relative humidity, atmospheric pollutants, and ultraviolet radiation. The test conditions, measurements, and data analyses for the accelerated tests are presented for determining the predicted life of the modules in service at Mead. Constant-temperature, cyclic-temperature, and uv types of tests are specified, incorporating selected levels of relative humidity and chemical contamination and an imposed forward-bias current and static electric field. It is recommended that as a first step in test implementation, the model be selectively validated using identified portions of the accelerated test design.

  2. Accelerating the design and testing of LEU fuel assemblies for conversion of Russian-designed research reactors outside Russia

    This paper identifies proposed geometries and loading specifications of LEU tube-type and pin-type test assemblies that would be suitable for accelerating the conversion of Russian-designed research reactors outside of Russia if these fuels are manufactured, qualified by irradiation testing, and made commercially available in Russia. (author)

  3. Optimal design of accelerated life tests for an extension of the exponential distribution

    Accelerated life tests provide information quickly on the lifetime distribution of the products by testing them at higher than usual levels of stress. In this paper, the lifetime of a product at any level of stress is assumed to have an extension of the exponential distribution. This new family has been recently introduced by Nadarajah and Haghighi (2011 [1]); it can be used as an alternative to the gamma, Weibull and exponentiated exponential distributions. The scale parameter of lifetime distribution at constant stress levels is assumed to be a log-linear function of the stress levels and a cumulative exposure model holds. For this model, the maximum likelihood estimates (MLEs) of the parameters, as well as the Fisher information matrix, are derived. The asymptotic variance of the scale parameter at a design stress is adopted as an optimization objective and its expression formula is provided using the maximum likelihood method. A Monte Carlo simulation study is carried out to examine the performance of these methods. The asymptotic confidence intervals for the parameters and hypothesis test for the parameter of interest are constructed

  4. Radiation resistance of polymer materials. Degradation evaluation by accelerated testing for application condition

    This paper presents re-evaluated radiation resistance property data of polymer materials, which had been tested in past times in TAKASAKI Quantum Beam Science Directorate, for the future study of ageing evaluation of low voltage electric cable insulation materials used in light-water nuclear reactors. The radiation resistance of 25 types of plastics and rubbers materials applied in practical environments was evaluated by the accelerated testing of gamma-ray irradiation under oxygen pressure, and was compared with the radiation resistance determined from the traditional testing by irradiation with a high dose rate in air. The polymer materials were formulated to be similar or equivalent to practical materials, and the most of formulation (chemical compounds and quantities) were described. For all materials, the tensile properties (elongation at break, ultimate strength, 100% or 200% modulus), electric resistivity, gel-fraction, and density were measured after irradiation in oxidation conditions and irradiation in air with a high dose rate (non-oxidation conditions). The data of relations between each properties and total dose at various conditions were compiled, and the relations among the changes of mechanical properties, electrical properties, and radiation induced chemical reactions were discussed. (author)

  5. Reliability demonstration methodology for products with Gamma Process by optimal accelerated degradation testing

    For products with high reliability and long lifetime, accelerated degradation testing (ADT) may be adopted during product development phase to verify whether its reliability satisfies the predetermined level within feasible test duration. The actual degradation from engineering is usually a strictly monotonic process, such as fatigue crack growth, wear, and erosion. However, the method for reliability demonstration by ADT with monotonic degradation process has not been investigated so far. This paper proposes a reliability demonstration methodology by ADT for this kind of product. We first apply Gamma process to describe the monotonic degradation. Next, we present a reliability demonstration method by converting the required reliability level into allowable cumulative degradation in ADT and comparing the actual accumulative degradation with the allowable level. Further, we suggest an analytical optimal ADT design method for more efficient reliability demonstration by minimizing the asymptotic variance of decision variable in reliability demonstration under the constraints of sample size, test duration, test cost, and predetermined decision risks. The method is validated and illustrated with example on reliability demonstration of alloy product, and is applied to demonstrate the wear reliability within long service duration of spherical plain bearing in the end. - Highlights: • We present a reliability demonstration method by ADT for products with monotonic degradation process, which may be applied to verify reliability with long service life for products with monotonic degradation process within feasible test duration. • We suggest an analytical optimal ADT design method for more efficient reliability demonstration, which differs from the existed optimal ADT design for more accurate reliability estimation by different objective function and different constraints. • The methods are applied to demonstrate the wear reliability within long service duration of

  6. Metodologia para o teste de envelhecimento acelerado em sementes de ervilha Accelerated aging test on pea seeds

    Warley Marcos Nascimento

    2007-06-01

    ível identificar os lotes de melhor qualidade.Pea production in Brazil uses seeds produced in the country. The objective of this study was to examine the efficiency of the accelerated aging test for vigor evaluation of pea seeds. Five seed lots of cultivar Axé (wrinkled seeds and five seed lots of cultivar Mikado (smooth seeds were used. The initial quality of each seed lot was evaluated by germination test, first counting, and seedling emergence in the field. Seed moisture content was also assessed. The accelerated aging test was set at 41ºC for periods of 24; 48; and 72 hours, with and without saturated NaCl solution. The experiment was carried out in a completely randomized design. The accelerated aging test was efficient for vigor evaluation of pea seeds, and the period of 48 hours at 41ºC, using saturated NaCl solution was the most adequate procedure to indicate vigor levels of pea seeds. However, the seed germination after this period was very low when compared to 24 hour-period (80% for both cultivars, even in higher vigor seed lots (35% for Axé and 38% for Mikado. In the saturated NaCl solution, the period of 48 hours at 41ºC was the most adequate for separate seeds through vigor levels. In these conditions, seed lots of highest vigor showed germination of 68% and 79% for Axé and Mikado, respectively. Results of the germination test, first counting, and seedling emergence were not effective in discriminating physiological seed quality when used individually. Nevertheless, when results from these tests were used all together, it was possible to identify the best seed lots.

  7. The conversion of CESR to operate as the Test Accelerator, CesrTA. Part 3: electron cloud diagnostics

    Billing, M. G.; Conway, J. V.; Crittenden, J. A.; Greenwald, S.; Li, Y.; Meller, R. E.; Strohman, C. R.; Sikora, J. P.; Calvey, J. R.; Palmer, M. A.

    2016-04-01

    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 is the third in a series of four describing the conversion of CESR to the test accelerator, CESRTA. The first two papers discuss the overall plan for the conversion of the storage ring to an instrument capable of studying advanced accelerator physics issues [1] and the details of the vacuum system upgrades [2]. This paper focusses on the necessary development of new instrumentation, situated in four dedicated experimental regions, capable of studying such phenomena as electron clouds (ECs) and methods to mitigate EC effects. The fourth paper in this series describes the vacuum system modifications of the superconducting wigglers to accommodate the diagnostic instrumentation for the study of EC behavior within wigglers. While the initial studies of CESRTA focussed on questions related to the International Linear Collider damping ring design, CESRTA is a very versatile storage ring, capable of studying a wide range of accelerator physics and instrumentation questions.

  8. Accelerated Lifetime Testing Methodology for Lifetime Estimation of Lithium-ion Batteries used in Augmented Wind Power Plants

    Stroe, Daniel Ioan; Swierczynski, Maciej Jozef; Stan, Ana-Irina;

    2014-01-01

    The development of lifetime estimation models for Lithium-ion battery cells, which are working under highly variable mission profiles characteristic for wind power plant applications, requires a lot of expenditures and time resources. Therefore, batteries have to be tested under accelerated...... lifetime ageing conditions. This paper presents a three-stage methodology used for accelerated lifetime testing of Lithium ion batteries. The results obtained at the end of the accelerated ageing process were used for the parametrization of a performance-degradation lifetime model, which is able to predict...... both the capacity fade and the power capability decrease of the selected Lithium-ion battery cells. In the proposed methodology both calendar and cycling lifetime tests were considered since both components are influencing the lifetime of Lithium-ion batteries. Furthermore, the proposed methodology was...

  9. VMAT linear accelerator commissioning and quality assurance: dose control and gantry speed tests.

    Barnes, Michael P; Rowshanfarzad, Pejman; Greer, Peter B

    2016-01-01

    In VMAT treatment delivery the ability of the linear accelerator (linac) to accurately control dose versus gantry angle is critical to delivering the plan correctly. A new VMAT test delivery was developed to specifically test the dose versus gantry angle with the full range of allowed gantry speeds and dose rates. The gantry-mounted IBA MatriXX with attached inclinometer was used in movie mode to measure the instantaneous relative dose versus gantry angle during the plan every 0.54 s. The results were compared to the expected relative dose at each gantry angle calculated from the plan. The same dataset was also used to compare the instantaneous gan-try speeds throughout the delivery compared to the expected gantry speeds from the plan. Measurements performed across four linacs generally show agreement between measurement and plan to within 1.5% in the constant dose rate regions and dose rate modulation within 0.1 s of the plan. Instantaneous gantry speed was measured to be within 0.11°/s of the plan (1 SD). An error in one linac was detected in that the nominal gantry speed was incorrectly calibrated. This test provides a practical method to quality-assure critical aspects of VMAT delivery including dose versus gantry angle and gantry speed control. The method can be performed with any detector that can acquire time-resolved dosimetric information that can be synchronized with a measurement of gantry angle. The test fulfils several of the aims of the recent Netherlands Commission on Radiation Dosimetry (NCS) Report 24, which provides recommendations for comprehensive VMAT quality assurance. PMID:27167282

  10. Testing MOND over a large acceleration range in x-ray ellipticals

    Milgrom, Mordehai

    2012-01-01

    The gravitational fields of two isolated ellipticals, NGC 720 and NGC 1521, have been recently measured, assuming hydrostatic balance of the hot gas enshrouding them. These galaxies are worthy of special interest: They afford, for the first time to my knowledge, testing MOND in ellipticals with force and quality that, arguably, approach those of rotation-curve tests in disc galaxies: The fields have been probed to very large galactic radii, revealing a large range of mass discrepancies. In the context of MOND, it is noteworthy that the measured accelerations span a wide range, from more than 10a0 to about a0/10, unprecedented in individual ellipticals. I compare the predictions of MOND, based on only the baryonic mass, for reasonable stellar M/L values, with the deduced dynamical mass runs of these galaxies. I find that MOND predicts correctly the runs of the mass discrepancies: from no discrepancy in the inner parts, to approximately a-factor-of-ten discrepancy in the outermost regions probed. For NGC 1521, ...

  11. Estimating service lifetimes of a polymer encapsulant for photovoltaic modules from accelerated testing

    Czanderna, A.W.; Pern, F.J. [National Renewable Energy Lab., Golden, CO (United States)

    1996-05-01

    In this paper, most of the emphasis is on A9918 ethylene vinyl acetate (EVA) used commercially as the pottant for encapsulating photovoltaic (PV) modules, in which the efficiencies in field-deployed modules have been reduced by 10-70% in 4-12 years. Yet, projections were made by several different research groups in the 1980s that the EVA lifetime could range from 2-100 years. The authors (1) elucidate the complexity of the encapsulation problem, (2) indicate the performance losses reported for PV systems deployed since 1981, (3) critically assess the service lifetime predictions for EVA as a PV pottant based on studies by others for which they review the inherent errors in their assumptions about the Arrhenius relation, (4) show how degradation of minimodules in laboratory experiments that simulate reality can produce efficiency losses comparable to those in field-degraded PV modules reported in the literature, and (5) outline an acceptable methodology for making a service lifetime prediction of the polymer encapsulant, including the essential need for relating accelerated lifetime testing to real-time testing with a sufficient number of samples.

  12. Testing MOND over a wide acceleration range in x-ray ellipticals.

    Milgrom, Mordehai

    2012-09-28

    The gravitational fields of two isolated ellipticals, NGC 720 and NGC 1521, have been recently measured to very large galactic radii (~100 and ~200 kpc), assuming hydrostatic balance of the hot gas enshrouding them. They afford, for the first time to my knowledge, testing modified Newtonian dynamics (MOND) in ellipticals with force and quality that, arguably, approach those of rotation-curve tests in disk galaxies. In the context of MOND, it is noteworthy that the measured accelerations span a wide range, from more than 10a(0) to about 0.1a(0), unprecedented in individual ellipticals. I find that MOND predicts correctly the measured dynamical mass runs (apart from a possible minor tension in the inner few kpc of NGC 720, which might be due to departure from hydrostatic equilibrium): The predicted mass discrepancy increases outward from none near the center, to ~10 at the outermost radii. The implications for the MOND-versus-dark-matter controversy go far beyond the simple fact of two more galaxies conforming to MOND. PMID:23030078

  13. Development of accelerated test design for service-life prediction of solar array at Mead, Nebraska. Quarterly report

    Gaines, G.B.; Thomas, R.E.; Noel, G.T.; Shilliday, T.S.; Wood, V.E.; Carmichael, D.C.

    1978-11-03

    As a significant beginning in applying accelerated tests to solar arrays for life-prediction purposes, this study is directed toward (a) developing a plan for predicting the service life of a specific solar array in a specific geographic site - viz., the 25-KW flat-plate array installed near Mead, Nebraska, and (b) developing technical information from laboratory and field measurements for designing an accelerated test that can be carried out in 2 years and have predictive validity for a service life as long as 20 years. Status of the program is described.

  14. Estimation of the Parameters of the Bivariate Generalized Exponential Distribution using Accelerated Life Testing with Censoring Data

    Salwa Asser

    2014-06-01

    Full Text Available In this paper, the estimation for the bivariate generalized exponential (BVGE distribution under type-I censored with constant stress accelerated life testing (CSALT are discussed. The scale parameter of the lifetime distribution at constant stress levels is assumed to be an inverse power law function of the stress level. The unknown parameters are estimated by the maximum likelihood approach and their approximate variance-covariance matrix is obtained. Then, the numerical studies are introduced to illustrate the approach study using samples which have been generated from the bivariate generalized exponential distribution. Keywords: Accelerated life testing, Bivariate generalized exponential distribution, Constant stress, Type-I censoring, Maximum likelihood estimation.

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

    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.

  16. Corrosion Testing in Support of the Accelerator Production of Tritium Program

    The Accelerator Production of Tritium Project is part of the United States Department of Energy strategy to meet the nation's tritium needs. The project involves the design of a proton beam accelerator, which will produce tritium through neutron/proton interaction with helium-3. Design, construction and operation of this one-of-a-kind facility will involve the utilization of a wide variety of materials exposed to unique conditions, including elevated temperature and high-energy mixed-proton and -neutron spectra. A comprehensive materials test program was established by the APT project which includes the irradiation of structural materials by exposure to high-energy protons and neutrons at the Los Alamos Neutron Science Center at the Los Alamos National Laboratory. Real-time corrosion measurements were performed on specially designed corrosion probes in water irradiated by an 800 MeV proton beam. The water test system provided a means for measuring water chemistry, dissolved hydroge n concentration, and the effects of water radiolysis and water quality on corrosion rate. The corrosion probes were constructed of candidate APT materials alloy 718, 316L stainless steel, 304L stainless steel, and 6061 Aluminum (T6 heat treatment), and alternate materials 5052 aluminum alloy, alloy 625, and C276. Real-time corrosion rates during proton irradiation increased with proton beam current. Efforts are continuing to determine the effect of proton beam characteristics and mixed-particle flux on the corrosion rate of materials located directly in the proton beam. This paper focuses on the real-time corrosion measurements of materials located in the supply stream and return stream of the water flow line to evaluate effects of long-lived radiolysis products and water chemistry on the corrosion rates of materials. In general, the corrosion rates for the out-of-beam probes were low and were affected mainly by water conductivity. The data indicate a water conductivity threshold e xists

  17. Imbibitions, energy test and accelerated ageing in primed and non-primed seeds of Peltophorum dubium

    LILei-hong; ZHANGWan-li; ZUYuan-gang; SONIAPerez

    2005-01-01

    Peltophorum dubium seeds were set to imbibe with four treatments, soaked with solution Captan 0.2% under 10and 27℃,PEG 6000 -1.0 MPa under 10 and 27℃. For each treatment there were four replicates with 40 seeds incubated in 9-cm Petri dishes with double filter paper moistened with testing solution. The imbibition curves showed that the final weight increase were from 70% to 150% in the treatments when imbibition entered a lag phase. Seeds were tested for effects on germination of five treatments: control group (nonprimed), primed with PEG6000 -1.0 MPa at 10 and 27℃, primed with Captan 0.2% at 10 and 27℃. For each treatment, there were three sub-treatments: seeds were soaked in distilled water for 12, 24 and 36h before the energy test. Germination percentages of nonprimed seeds and primed in PEG 27℃ soaked in distilled water during 12 h were the highest, reaching 100%. The lowest germination percentage occurred primed seeds with PEG6000 27℃ and soaked in distilled water during 36 h, which was only 52%. Germination mean time of primed seeds in PEG at 10℃, soaked 24 h was 1.08 days, mean time of primed seeds in PEG at 27℃ soaked 12 h was 2.42 days. Accelerated ageing results showed low or no germination after ageing 72 h. Control group had a higher germination percentage and seeds were more resistant to deterioration than those in primed groups, both in Petri dish (27℃) and vermiculate (room temperature).

  18. Coating and Interface Degradation of Coated steel, Part 2: Accelerated Laboratory Tests

    In a previous paper, it was demonstrated that the measurement of cathodic delamination by the Scanning Kelvin Probe can assess the interface stability of poly(vinyl butyral) (PVB) coated steel after field exposure. This technique was utilized to characterize the degradation of the polymer/metal interface in several outdoor climates. In this paper, the effects of environmental factors on the interface degradation were investigated in the laboratory. The mechanisms measured in the field were reproduced to provide input in the development of an appropriate accelerated test for PVB coated steel. The ASTM B117 and G154 standardized tests were investigated individually and sequentially. The interface stability improved after 24 h of ASTM G154 exposure. After 144 h of exposure to ASTM G154 exposure, polymer oxidation took place simultaneously with interface degradation. The condensation phase of the ASTM G154 test was responsible for the interface improvement while the ultraviolet radiation triggered the interface degradation. Pre-exposure to ASTM G154 delayed wet de-adhesion during ASTM B117 exposure. After wet de-adhesion caused by 6 h of ASTM B117, exposure to ASTM G154 for 24 h increased the interface stability. The effects of ultraviolet radiation, relative humidity, temperature and environment on interface degradation were investigated in a special chamber. Humidity was the primary factor found to influence the interface improvement during G154 exposure. A wet/dry salt fog cycle with irradiation by an ultraviolet or filtered xenon arc lamp around room temperature was suggested to reproduce the competition between the interface improvement and the interface degradation that takes place in the field

  19. The conversion of CESR to operate as the Test Accelerator, CesrTA. Part 2: vacuum modifications

    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, the second in a series of four, discusses the modifications of the vacuum system necessary for the conversion of CESR to the test accelerator, CESR-TA, 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. A separate paper describes the vacuum system modifications of the superconducting wigglers to accommodate the diagnostic instrumentation for the study of EC behavior within wigglers. While the initial studies of CESR-TA focussed on questions related to the International Linear Collider (ILC) damping ring design, CESR-TA is a very flexible storage ring, capable of studying a wide range of accelerator physics and instrumentation questions

  20. The Conversion of CESR to Operate as the Test Accelerator, CesrTA, Part 3: Electron Cloud Diagnostics

    Billing, M G; Crittendan, J A; Greenwald, S; Li, Y; Meller, R E; Strohman, C R; Sikora, J P; Calvey, J R; Palmer, M A

    2015-01-01

    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 is the third in a series of four describing the the conversion of CESR to the test accelerator, CesrTA. The first two papers discuss the overall plan for the conversion of the storage ring to an instrument capable of studying advanced accelerator physics issues and the details of the vacuum system upgrades. This paper focusses on the necessary development of new instrumentation, situated in four dedicated experimental regions, capable of studying such phe...

  1. On the design and testing of solid armatures for rail accelerator applications

    Karthaus, W.; de Zeeuw, W.A.; Kolkert, W.J. (TNO PML-Pulse Physics (NL))

    1991-01-01

    Two different armature designs, for rail accelerator applications have been studied during electromagnetic launch experiments. The designs investigated are an aluminium multi-finger monoblock and a copper fiber brush armature. The experimental set-up used and the results obtained together with an electro-thermal model that describes the armature interface behavior during the acceleration process itself are presented in this paper.

  2. Monitoring accelerated carbonation on standard Portland cement mortar by nonlinear resonance acoustic test

    Eiras, J. N.; Kundu, T.; Popovics, J. S.; Monzó, J.; Borrachero, M. V.; Payá, J.

    2015-03-01

    Carbonation is an important deleterious process for concrete structures. Carbonation begins when carbon dioxide (CO2) present in the atmosphere reacts with portlandite producing calcium carbonate (CaCO3). In severe carbonation conditions, C-S-H gel is decomposed into silica gel (SiO2.nH2O) and CaCO3. As a result, concrete pore water pH decreases (usually below 10) and eventually steel reinforcing bars become unprotected from corrosion agents. Usually, the carbonation of the cementing matrix reduces the porosity, because CaCO3 crystals (calcite and vaterite) occupy more volume than portlandite. In this study, an accelerated carbonation-ageing process is conducted on Portland cement mortar samples with water to cement ratio of 0.5. The evolution of the carbonation process on mortar is monitored at different levels of ageing until the mortar is almost fully carbonated. A nondestructive technique based on nonlinear acoustic resonance is used to monitor the variation of the constitutive properties upon carbonation. At selected levels of ageing, the compressive strength is obtained. From fractured surfaces the depth of carbonation is determined with phenolphthalein solution. An image analysis of the fractured surfaces is used to quantify the depth of carbonation. The results from resonant acoustic tests revealed a progressive increase of stiffness and a decrease of material nonlinearity.

  3. Final safety analysis report for the Ground Test Accelerator (GTA), Phase 2

    NONE

    1994-10-01

    This document is the second volume of a 3 volume safety analysis report on the Ground Test Accelerator (GTA). The GTA program at the Los Alamos National Laboratory (LANL) is the major element of the national Neutral Particle Beam (NPB) program, which is supported by the Strategic Defense Initiative Office (SDIO). A principal goal of the national NPB program is to assess the feasibility of using hydrogen and deuterium neutral particle beams outside the Earth`s atmosphere. The main effort of the NPB program at Los Alamos concentrates on developing the GTA. The GTA is classified as a low-hazard facility, except for the cryogenic-cooling system, which is classified as a moderate-hazard facility. This volume consists of failure modes and effects analysis; accident analysis; operational safety requirements; quality assurance program; ES&H management program; environmental, safety, and health systems critical to safety; summary of waste-management program; environmental monitoring program; facility expansion, decontamination, and decommissioning; summary of emergency response plan; summary plan for employee training; summary plan for operating procedures; glossary; and appendices A and B.

  4. ACCELERATED LABORATORY TEST OF RUBBERWOOD ORIENTED STRANDBOARD EXPOSED TO WOOD DECAY FUNGI

    Esmeralda Yoshico Arakaki Okino

    2009-10-01

    Full Text Available This work aimed to evaluate the natural durability of oriented strandboards (OSB manufactured with strands of Hevea brasiliensis Müll.Arg. bonded with 5% and 8% of urea-formaldehyde (UF and phenol-formadehyde (FF resins, exposed to xilophagous fungi under laboratory conditions. In accelerated laboratory test decay, samples of OSB were exposed to the following fungi: the brown-rot fungi Gloeophyllum trabeum (Pers. ex Fries Murr., Coniophora puteana (Schumach. : Fr.P. Karst., Meruliporia incrassata (Berk. & M.A. Curtis Murrill as well as the white-rot fungi Fomes annosus (Fr. : Fr. Cooke, Trametes versicolor (L. : Fr. Pilát, Ganoderma applanatum (Pers. Pat., Bjerkandera fumosa (Pers. : Fr. P. Karst. and Phanerochaete chrysosporium Burds. Among the brown-rot fungi, the Gloeophyllum trabeum was the most aggressive, showing the highest loss of mass. Trametes versicolor and Ganoderma applanatum confirmed the preference for broadleave species. All oriented strandboards at lower UF resin contents were more degraded by Phanerochaete chrysosporium, Trametes versicolor, Ganoderma applanatum, Merulia incrassata, Coniophora puteana and Gloeophyllum trabeum, with high rate of loss of mass. Coniophora puteana showed small loss of mass when FF resin was applied. Bjerkandera fumosa showed low loss of mass only at higher resin content. Oriented strandboards exposed to Coniophora puteana showed insignificant OSB degradation.

  5. Operation and postirradiation examination of ORR capsule OF-2: accelerated testing of HTGR fuel

    Irradiation capsule OF-2 was a test of High-Temperature Gas-Cooled Reactor fuel types under accelerated irradiation conditions in the Oak Ridge Research Reactor. The results showed good irradiation performance of Triso-coated weak-acid-resin fissile particles and Biso-coated fertile particles. These particles had been coated by a fritted gas distributor in the 0.13-m-diam furnace. Fast-neutron damage (E > 0.18 MeV) and matrix-particle interaction caused the outer pyrocarbon coating on the Triso-coated particles to fail. Such failure depended on the optical anisotropy, density, and open porosity of the outer pyrocarbon coating, as well as on the coke yield of the matrix. Irradiation of specimens with values outside prescribed limits for these properties increased the failure rate of their outer pyrocarbon coating. Good irradiation performance was observed for weak-acid-resin particles with conversions in the range from 15 to 75% UC2

  6. Utilization of optical image data from the Advanced Test Accelerator (ATA)

    Extensive use is made of optical diagnostics to obtain information on the 50-MeV, 10-kA, 70-ns pulsed-electron beam produced by the Advanced Test Accelerator (ATA). Light is generated by the beam striking a foil inserted in the beamline or through excitation of the gas when the beamline is filled with air. The emitted light is collected and digitized. Two-dimensional images are recorded by either a gated framing camera or a streak camera. Extraction of relevant beam parameters, such as current density, current, and beam size, requires an understanding of the physics of the light-generation mechanism and an ability to handle and properly exploit a large digital database of image data. We will present a brief overview of the present understanding of the light-generation mechanisms in foil and gas, with emphasis on experimental observations and trends. We will review our data management and analysis techniques and indicate successful approaches for extracting beam parameters

  7. Recovery mechanisms in proton exchange membrane fuel cells after accelerated stress tests

    Zhang, Xu; Guo, Liejin; Liu, Hongtan

    2015-11-01

    The mechanisms of performance recovery after accelerated stress test (AST) in proton exchange membrane fuel cells (PEMFCs) are systematically studied. Experiments are carried out by incorporating a well-designed performance recovery procedure right after the AST protocol. The experiment results show that the cell performance recovers significantly from the degraded state after the AST procedure. The results from cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements further show that the performance recovery can be divided into kinetic and mass transport recoveries. It is further determined that the kinetic recovery, i.e. the recovery of electrochemical active area (ECA), is due to two distinct mechanisms: the reduction of platinum oxide and the re-attachment of detached platinum nanoparticles onto the carbon surface. The mass transport resistance is probably due to reduction of hydrophilic oxide groups on the carbon surface and the microstructure change that alleviates flooding. Performance comparisons show that the recovery procedure is highly effective, indicating the results of AST significantly over-estimate the true degradation in a PEM fuel cell. Therefore, a recovery procedure is highly recommended when an AST protocol is used to evaluate cell degradations to avoid over-estimating true performance degradations in PEMFCs.

  8. Test of the Pauli exclusion principle for nucleons and atomic electrons by accelerator mass spectrometry

    The Pauli exclusion principle was tested by searching with accelerator mass spectrometry for non-Paulian atoms with three electrons in the K-shell and for non-Paulian nuclei with three protons or three neutrons in the nuclear 1 s1/2 shell. For non-Paulian atoms of 20Ne and 36Ar the following limits have been obtained: N(20Ne)/N(20Ne)-21 and N(36Ar)/N(36Ar)-17. For non-Paulian nuclei of 5Li and 5He with three protons or three neutrons, respectively, in the nuclear 1 s1/2 shell the following limits have been measured: N(5Li)/N(6Li)-17 for a range of proton separation energies of 5Li between 0 and 50 MeV and N(5He)/N(4He)-15 for neutron separation energies between 0 and 32 MeV. The result for 5Li is used to deduce a limit for the probability β2/2 of finding two colliding protons in the symmetric state with respect to exchange to be β2/2-32. (orig.)

  9. A modified feed-forward control system at the Accelerator Test Facility

    A modified feed-forward control system has been operated at the Brookhaven Accelerator Test Facility to control the phase and amplitude of two high power klystron rf systems used to power a photocathode rf gun and a traveling wave electron linac. The changes to the control algorithm include an improved handling of cross coupling between the amplitude and the phase channels, an improved calibration routine that allows for changes in the matrix elements due to the variable base-line and improved filtering. The modifications to the software include modularity, portability, and user-friendliness. Improvements to the hardware include a linearized phase and amplitude controller with dc biasing for an improved dynamic range. The feed-forward system can handle nonlinear and noninstantaneous systems. With simultaneous regulation of two channels, the phase and the amplitude fluctuations over a time span of more than 3 μS were reduced to less than ±0.2 degree and ±0.2%, from the initial ±2.7 degree and ±1.8%, respectively. copyright 1997 American Institute of Physics

  10. Accelerated aging tests of radiation damaged lasers and photodiodes for the CMS tracker optical links

    Gill, K; Batten, J; Cervelli, G; Grabit, R; Jensen, F; Troska, Jan K; Vasey, F

    1999-01-01

    The combined effects of radiation damage and accelerated ageing in COTS lasers and p-i-n photodiodes are presented. Large numbers of these devices are employed in future High Energy Physics experiments and it is vital that these devices are confirmed to be sufficiently robust in terms of both radiation resistance and reliability. Forty 1310 nm InGaAsP edge-emitting lasers (20 irradiated) and 30 InGaAs p- i-n photodiodes (19 irradiated) were aged for 4000 hours at 80 degrees C with periodic measurements made of laser threshold and efficiency, in addition to p-i-n leakage current and photocurrent. There were no sudden failures and there was very little wearout- related degradation in either unirradiated or irradiated sample groups. The results suggest that the tested devices have a sufficiently long lifetime to operate for at least 10 years inside the Compact Muon Solenoid experiment despite being exposed to a harsh radiation environment. (13 refs).

  11. Measurement and Compensation of Horizontal Crabbing at the Cornell Electron Storage Ring Test Accelerator

    Ehrlichman, M P; Hartung, W; Peterson, D P; Rider, N; Rubin, D; Sagan, D; Shanks, J P; Wang, S T

    2013-01-01

    In storage rings, horizontal dispersion in the rf cavities introduces horizontal-longitudinal ($xz$) coupling, contributing to beam tilt in the $xz$ plane. This coupling can be characterized by a "crabbing" dispersion term $\\zeta_a$ that comes from decomposing the $1$-turn transfer matrix. $\\zeta_a$ is proportional to the rf cavity voltage and the horizontal dispersion in the cavity. We report experiments at the Cornell Electron Storage Ring Test Accelerator (CesrTA) where $xz$ coupling was explored using three lattices with distinct crabbing properties. We characterize the $xz$ coupling for each case by measuring the horizontal projection of the beam with a beam size monitor. The three lattice configurations correspond to a) $16$ mrad $xz$ tilt at the beam size monitor source point, b) compensation of the $\\zeta_a$ introduced by one of two pairs of RF cavities with the second, and c) zero dispersion in RF cavities, eliminating $\\zeta_a$ entirely. Additionally, intrabeam scattering (IBS) is evident in our mea...

  12. Particle acceleration and plasma energization in substorms: MHD and test particle studies

    Birn, Joachim [Los Alamos National Laboratory

    2015-07-16

    The author organizes his slide presentation under the following topics: background, MHD simulation, orbit integration, typical orbits, spatial and temporal features, acceleration mechanisms, source locations, and source energies. Field-­aligned energetic particle fluxes are shown for 45-keV electrons and 80-keV protons. It is concluded that the onset from local thin current sheet is electron tearing. Acceleration is mainly from field collapse, governed by Ey = -vxXBz: importance of localization; betatron acceleration (similar if nonadiabatic); 1st order Fermi, type B (or A; current sheet acceleration). There are two source regions (of comparable importance in magnetotail): - flanks, inner tail - drift entry - early, higher energy - outer plasma sheet - reconnection entry - later, lower energy. Both thermal and suprathermal sources are important, with limited energy range for acceleration

  13. Development of an accelerated test design for predicting the service life of the solar array at Mead, Nebraska. Quarterly report

    Gaines, G.B.; Thomas, R.E.; Noel, G.T.; Shilliday, T.S.; Wood, V.E.; Carmichael, D.C.

    1979-02-06

    Economic viability requires that photovoltaic arrays should have a service life of 20 years or longer. Qualification and performance tests indicate that presently available photovoltaic modules provide acceptable performance at the time of installation. This study is being conducted as part of a program to develop and validate an accelerated test plan that can be used to predict the useful service life of present and future solar arrays. Previously a methodology was developed for designing an accelerated test program incorporating trade-offs between the cost of each test and its value in reducing the variance in the life prediction for that array. The objective of the present study is to apply this methodology to develop an accelerated test plan to predict the service life of the 25-kW photovoltaic array installed near Mead, Nebraska. Potential long-term degradation modes for the two types of modules in the Mead array have been determined and judgments have been made as to those environmental stresses and combinations of stresses which accelerate the degradation of the power output. Hierarchical trees representing the severity of effects of stresses (test conditions) on eleven individual degradation modes have been constructed and have been pruned of tests judged to be nonessential. Composites of those trees have been developed so that there is now one pruned tree covering eight degradation modes, another covering two degradation modes, and a third covering one degradation mode. These three composite trees form the basis for selection of test conditions in the final test plan which is now being prepared.

  14. Performance degradation, polymer encapsulant degradation, and estimating lifetimes for photovoltaic modules from accelerated testing

    Czanderna, A.W.; Pern, F.J. [National Renewable Energy Lab., Golden, CO (United States)

    1996-12-31

    The purposes of this paper are to provide background information about encapsulants for photovoltaic (PV) modules and to evaluate estimates of the durability of different materials used in PV modules. The authors summarize the field-deployed module degradation in performance, the established degradation mechanisms of ethylene vinyl acetate (EVA) copolymer, and potential degradation mechanisms in other module components and at materials interfaces. Most of the emphasis is on estimates for the commercially used EVA formulations A9918 and 15295. These formulations have degraded in field-deployed modules to produce acetic acid and a yellow to brown color from polyenes and the module efficiencies have been reduced by 10% to 70% in 4 to 12 years. Yet, projections were made by several different research groups in the 1980s that the EVA lifetime could range from 20 to 100 years, the production of acetic acid would only be 0.006% in 20 years, and that silver metallization would survive attack from acetic acid for 300 years at 55 C. Those authors did not use appropriate variables or specimen configurations that simulate reality, and based their projections using the generalization that chemical reaction rates double for every 10 C increase in T. The authors review the inherent errors in their assumptions about the Arrhenius relation. They also show how degradation in efficiency (from current-voltage data) comparable to field experience is obtained using minimodules with a construction that simulates reality and by using appropriate variables in accelerated testing, i.e., UV, T, and RH. A test protocol is outlined that simulates reality and permits making suitable service lifetime projections.

  15. Development and test of an accelerating cavity shape for a superconducting linear collider

    In order to use superconducting RF accelerating structures in the construction of a linear collider certain criteria must be addressed. Foremost of these criteria is the high accelerating gradient. This requirement might be more accurately expressed as the accelerating gradient per unit cost. The authors see therefore that cost/unit length is also a primary criteria. The cavity must be designed so that input power can be coupled in and higher order mode (HOM) power may be coupled out to the degree required by beam stability considerations. At this time in the development of superconducting RF accelerating cavities, the accelerating gradient is limited by two phenomena, electron field emission and thermal breakdown. The first of these makes it imperative to choose a cell shape that minimizes Epk/Eacc and the second phenomena to minimize Hpk/Eacc (the ratio of the peak surface fields to the accelerating gradient). As field emission is the dominant gradient limitation, there is considerable premium in lowering Epk/Eacc. The cell to cell coupling (K) is also effected by the shape. This is true of the coupling of the HOM's as well as the fundamental TM010 mode. Because of this, the number of coupled cells comprising an accelerating unit is limited. A larger number of cells/module helps reduce the structure cost by reducing the number of couplers as well as by improving the filling factor for the machine. An effort is made here to increase the number of cells per module to 10

  16. Accelerated tests for the soft error rate determination of single radiation particles in components of terrestrial and avionic electronic systems

    This paper describes the main features of the accelerated test procedures used to determine reliability data of microelectronics devices used in terrestrial environment.This paper focuses on the high energy particle test that could be performed through spallation neutron source or quasi-mono-energetic neutron or proton. Improvements of standards are illustrated with respect to the state of the art of knowledge in radiation effects and scaling down of microelectronics technologies. (authors)

  17. Corrosion Embrittlement of Duralumin II Accelerated Corrosion Tests and the Behavior of High-Strength Aluminum Alloys of Different Compositions

    Rawdon, Henry S

    1928-01-01

    The permanence, with respect to corrosion, of light aluminum alloy sheets of the duralumin type, that is, heat-treatable alloys containing Cu, Mg, Mn, and Si is discussed. Alloys of this type are subject to surface corrosion and corrosion of the interior by intercrystalline paths. Results are given of accelerated corrosion tests, tensile tests, the effect on corrosion of various alloying elements and heat treatments, electrical resistance measurements, and X-ray examinations.

  18. Installation, tests and start up of the Tandetron positive ions accelerator

    The National Institute of Nuclear Research acquired a Positive ions accelerator type Tandetron 2MV of the Dutch Company High Voltage Engineering, Europe B.V. (H.V.E.E.) which was installed in the building named Irradiator Nave which is occupied by the Gamma irradiator and the Pelletron accelerator. Starting from the accelerator selection it was defined the conditions required for the operation of this as well as: electric feeding, water quality and quantity, air compressed, temperature, humidity, etc.; as well as the necessary modifications of the installation area. (Author)

  19. Status of the visible Free-Electron Laser at the Brookhaven Accelerator Test Facility

    The 500 nm Free-Electron Laser (ATF) of the Brookhaven National Laboratory is reviewed. We present an overview of the ATF, a high-brightness, 50-MeV, electron accelerator and laser complex which is a users' facility for accelerator and beam physics. A number of laser acceleration and FEL experiments are under construction at the ATF. The visible FEL experiment is based on a novel superferric 8.8 mm period undulator. The electron beam parameters, the undulator, the optical resonator, optical and electron beam diagnostics are discussed. The operational status of the experiment is presented. 22 refs., 7 figs

  20. Life prediction of 808nm high power semiconductor laser by accelerated life test of constant current stress

    Yao, Nan; Li, Wei; Zhao, Yihao; Zhong, Li; Liu, Suping; Ma, Xiaoyu

    2015-10-01

    High power semiconductor laser is widely used because of its high transformation efficiency, good working stability, compact volume and simple driving requirements. Laser's lifetime is very long, but tests at high levels of stress can speed up the failure process and shorten the times to failure significantly. So accelerated life test is used here for forecasting the lifetime of 808nm CW GaAs/AlGaAs high power semiconductor laser that has an output power of 1W under 1.04A. Accelerated life test of constant current stress based on the Inverse Power Law Relationship was designed. Tests were conducted under 1.3A, 1.6A and 1.9A at room temperature. It is the first time that this method is used in the domestic research of laser's lifetime prediction. Applying Weibull Distribution to describe the lifetime distribution and analyzing the data of times to failure, characteristics lifetime's functional relationship model with current is achieved. Then the characteristics lifetime under normal current is extrapolated, which is 9473h. Besides, to confirm the validity of the functional relationship model, we conduct an additional accelerated life test under 1.75A. Based on this experimental data we calculated the characteristics lifetime corresponding to 1.75A that is 171h, while the extrapolated characteristics lifetime from the former functional relationship model is 162h. The two results shows 5% deviation that is very low and acceptable, which indicates that the test design is reasonable and authentic.

  1. Evaluation of oxidative behavior of polyolefin geosynthetics utilizing accelerated aging tests based on temperature and pressure

    Li, Mengjia

    Polyolefin geosynthetics are susceptible to oxidation, which eventually leads to the reduction in their engineering properties. In the application of polyolefin geosynthetics, a major issue is an estimate of the materials durability (i.e. service lifetime) under various aging conditions. Antioxidant packages are added to the polyolefin products to extend the induction time, during which antioxidants are gradually depleted and polymer oxidation reactions are prevented. In this PhD study, an improved laboratory accelerating aging method under elevated and high pressure environments was applied to evaluate the combined effect of temperature and pressure on the depletion of the antioxidants and the oxidation of polymers. Four types of commercial polyolefn geosynthetic materials selected for aging tests included HDPE geogrid, polypropylene woven and nonwoven geotextiles. A total of 33 different temperature/pressure aging conditions were used, with the incubation duration up to 24 months. The applied oven temperature ranged from 35°C to 105°C and the partial oxygen pressure ranged from 0.005 MPa to 6.3 MPa. Using the Oxidative Induction Time (OIT) test, the antioxidant depletion, which is correlated to the decrease of the OIT value, was found to follow apparent first-order decay. The OIT data also showed that, the antioxidant depletion rate increased with temperature according to the Arrhenius equation, while under constant temperatures, the rate increased exponentially with the partial pressure of oxygen. A modified Arrhenius model was developed to fit the antioxidant depletion rate as a function of temperature and pressure and to predict the antioxidant lifetime under various field conditions. This study has developed new temperature/pressure incubation aging test method with lifetime prediction models. Using this new technique, the antioxidant lifetime prediction results are close to regular temperature aging data while the aging duration can be reduced considerably

  2. Test method for position of accelerate grid of megawatt level high current ion source

    Background: Accelerate grid for producing several tens of MW ion beams is a critical component of the megawatt level high current ion source for the high power neutral beam injection, Purpose: To measure and analyze the position of accelerate grid. Methods: Taking the exit grid module of EAST-NBI high current ion source as the measurement object, the observation point coordinates of accelerate grid rail's actual axis are obtained by using 3 quadrant points sampling method and the point coordinates are analyzed by using MATLAB optimal function. Results: The position error that tallies with minimum zone and the distribution regularities of accelerate grid rails are obtained. Conclusions: This method has simple and stable course of evaluating, can realize automatic measurement and provide the basis for improving and finalizing the grid module's processing technic. (authors)

  3. Electron cloud dynamics in the Cornell Electron Storage Ring Test Accelerator wiggler

    Celata, C. M.

    2011-01-01

    The interference of stray electrons (also called “electron clouds”) with accelerator beams is important in modern intense-beam accelerators, especially those with beams of positive charge. In magnetic wigglers, used, for instance, for transverse emittance damping, the intense synchrotron radiation produced by the beam can generate an electron cloud of relatively high density. In this paper the complicated dynamics of electron clouds in wigglers is examined using the example of a wiggler in th...

  4. Accelerated Cosmological Models in Modified Gravity tested by distant Supernovae SNIa data

    Borowiec, Andrzej; Godlowski, Wlodzimierz; Szydlowski, Marek

    2006-01-01

    Recent supernovae of type Ia measurements and other astronomical observations suggest that our universe is in accelerating phase of evolution at the present epoch. While a dark energy of unknown form is usually proposed as the most feasible mechanism for the acceleration, there are appears some alternative conception that some effects arising from generalization of Einstein equation can mimic dark energy through a modified Friedmann equation. In this work we investigate some observational con...

  5. An End-to-End Test of Neutron Stars as Particle Accelerators

    CARAVEO, PATRIZIA A.

    2005-01-01

    Combining resolved spectroscopy with deep imaging, XMM-Newton is providing new insights on the particle acceleration processes long known to be at work in the magnetospheres of isolated neutron stars. According to a standard theoretical interpretation, in neutron stars' magnetospheres particles are accelerated along the B field lines and, depending on their charge, they can either move outward, to propagate in space, or be funnelled back, towards the star surface. While particles impinging on...

  6. Lead-bismuth spallation target design of the accelerator-driven test facility (ADTF)

    A design methodology for the lead-bismuth eutectic (LBE) spallation target has been developed and applied for the accelerator-driven test facility (ADTF) target. This methodology includes the target interface with the subcritical multiplier (SCM) of the ADTF and the different engineering aspects of the target design, physics, heat-transfer, hydraulics, structural, radiological, and safety analyses. Several design constrains were defined and utilised for the target design process to satisfy different engineering requirements and to minimise the time and the cost of the design development. Interface requirements with the subcritical multiplier were defined based on target performance parameters and material damage issues to enhance the lifetime of the target structure. Different structural materials were considered to define the most promising candidate based on the current database including radiation effects. The developed target design has a coaxial geometrical configuration to minimise the target footprint and it is installed vertically along the SCM axis. LBE is the target material and the target coolant with ferritic steel (HT-9 Alloy) structural material. The proton beam has 8.33 mA current uniformly distributed and 8.14 cm beam radius resulting in a current density of 40 μA/cm2. The beam power is 5 MW and the proton energy is 600 MeV. The beam tube has 10 cm radius to accommodate the halo current. A hemi-spherical geometry is used for the target window, which is connected to the beam tube. The beam tube is enclosed inside two coaxial tubes to provide inlet and outlet manifolds for the LBE coolant. The inlet and the outlet coolant manifolds and the proton beam are entered from the top above the SCM. The paper describes the design criteria, engineering constraints, and the developed target design for the ADTF. (authors)

  7. Experimental test of a new antiproton acceleration scheme in the Fermilab Main Injector

    In an effort to provide higher intensity and lower emittance antiproton beam to the Tevatron collider for high luminosity operation, a new Main Injector (MI) antiproton acceleration scheme has been developed [1-4]. In this scheme, beam is accelerated from 8 to 27 GeV using the 2.5 MHz rf system and from 27 to 150 GeV using the 53 MHz rf system. This paper reports the experimental results of beam study. Simulation results are reported in a different PAC'05 paper [5]. Experiments are conducted with proton beam from the Booster. Acceleration efficiency, emittance growth and beam harmonic transfer between 2.5 MHz (h=28) and 53 MHz (h=588) buckets have been studied. Beam study shows that one can achieve an overall acceleration efficiency of about 100%, longitudinal emittance growth less than 20% and negligible transverse emittance growth. accelerated to 150 GeV and injected to the Tevatron. The multi-bunch coalescing process is eliminated in this acceleration scheme. Consequently, longitudinal emittance growth is reduced. Smaller emittance growth reduces beam loss

  8. The Conversion of CESR to Operate as the Test Accelerator, CesrTA, Part 2: Vacuum Modifications

    Billing, M G

    2015-01-01

    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, the second in a series of four, discusses the modifications of the vacuum system necessary for the conversion of CESR to the 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. A separate paper describes the vacuum system modifications of the superconducting wigglers to accommodate the ...

  9. LIBO accelerates

    2002-01-01

    The prototype module of LIBO, a linear accelerator project designed for cancer therapy, has passed its first proton-beam acceleration test. In parallel a new version - LIBO-30 - is being developed, which promises to open up even more interesting avenues.

  10. Assembly Test of Elastic Averaging Technique to Improve Mechanical Alignment for Accelerating Structure Assemblies in CLIC

    Huopana, J

    2010-01-01

    The CLIC (Compact LInear Collider) is being studied at CERN as a potential multi-TeV e+e- collider [1]. The manufacturing and assembly tolerances for the required RF-components are important for the final efficiency and for the operation of CLIC. The proper function of an accelerating structure is very sensitive to errors in shape and location of the accelerating cavity. This causes considerable issues in the field of mechanical design and manufacturing. Currently the design of the accelerating structures is a disk design. Alternatively it is possible to create the accelerating assembly from quadrants, which favour the mass manufacturing. The functional shape inside of the accelerating structure remains the same and a single assembly uses less parts. The alignment of these quadrants has been previously made kinematic by using steel pins or spheres to align the pieces together. This method proved to be a quite tedious and time consuming method of assembly. To limit the number of different error sources, a meth...

  11. A null test of the metric nature of the cosmic acceleration

    We discuss the testable predictions of a phenomenological model in which the accelerated expansion of the universe is the result of the action of a non-gravitational force field, rather than the effect of a negative-pressure dark energy fluid or a modification of general relativity. We show, through the equivalence principle, that in such a scenario the cosmic acceleration felt by distant standard candles like SNIa (type Ia supernovae (SNe)) depends on the mass of the host system, being larger in isolated galaxies than in rich clusters. As a consequence, the scatter in the observed SNIa Hubble diagram has mostly a physical origin in this scenario: in fact, the SNIa distance modulus is increasing, at fixed redshift, for SNe that are hosted in isolated galaxies with respect to the case of SNe hosted in rich galaxy clusters. Due to its strong dependence on the astrophysical environments of standard candles, we conclude that alternative non-gravitational mechanisms for the observed accelerated expansion of the universe can be interestingly contrasted against the standard metric interpretation of the cosmological acceleration by means of an environmental analysis of the cosmic structures in which SNIa are found. The possible absence of such environmental effects would definitely exclude the possibility of non-gravitational mechanisms being responsible for the accelerated cosmological expansion and will therefore reinforce a metric interpretation

  12. Laboratory test of Newton's law of gravity for small accelerations

    The rotation curves of spiral galaxies suggest that either a considerable fraction of the galactic mass must be dark matter, or that one of Newton's laws needs revision at accelerations less than 1×10−10 m s−2. We have endeavored to search for evidence of the latter in a terrestrial laboratory. A sensitive torsion balance was employed to measure small accelerations due to gravity. No deviations from the predictions of Newton's law were found down to 1 × 10−12 m s−2. (paper)

  13. ZZ ADS-LIB/V1.0, test library for Accelerator Driven Systems

    1 - Description: This test library can be used for a number of code systems in the analysis of Accelerator Driven Systems (ADS). The library is restricted to those materials needed for benchmarking efforts linked to short and mid-term ADS experimental results and design concepts. The 30 materials selected and the upper energy limit of the evaluation of each of them is given in parentheses. Format: ENDF-6. Number of groups: continuous energy for ACE library, 421 neutron groups for MATXS library. Nuclides: H1 (150), O16 (150), Al27 (150), Ti46 (20), Ti47 (20), Ti48 (20), Ti49 (20), Ti50 (20), Cr50 (20), Cr52 (20), Cr53 (20), Cr54 (20), Mn55 (20), Fe54 (200), Fe56 (200), Fe57 (200), Fe58 (200), Ni58 (20), Ni60 (20), Ni61 (150), Ni62 (150), Ni64 (150), Pb204 (200), Pb206 (200), Pb207 (200), Pb208 (200), Th232 (20), U234 (20), U235 (20), U238 (30). Thermal scattering: Thermal scattering Data for Hydrogen bound in water, 293.6 K, 323.6 K, 373.6 K, 423.6 K, 473.6 K, 523.6 K, 573.6 K, 623.6 K. Temperatures: for H1: [293.6, 323.6, 373.6, 423.6, 473.6, 523.6, 573.6, 623.6 K]; for Actinides and O-16: [293.6, 400, 500, 600, 700, 800, 900, 1200 K]; and for the rest of materials: [293.6, 400, 500, 600, 700, 800, 900 K]. Origin: JEFF3.1. Neutron weighting spectrum: standard PWR spectrum included in the GROUPR module of NJOY, modified in such a way that follows the 1/E shape from 4.0 eV to 9.811 KeV and from 10 to 20 MeV. Background scattering: sigma-0, between 5 and 10, depending on the nuclide in the range 1-10 E10. Legendre order: P-6 for transport correction to P-5. 2 - Methods: Processing was carried out using NJOY-99.90 with the local updates at IAEA-NDS. The resulting processed files are available in ACE format for Monte Carlo transport calculations and in MATXS format for deterministic transport calculations

  14. Electron Lenses for Experiments on Nonlinear Dynamics with Wide Stable Tune Spreads in the Fermilab Integrable Optics Test Accelerator

    Stancari, G. [Fermilab; Carlson, K. [Fermilab; McGee, M. W. [Fermilab; Nobrega, L. E. [Fermilab; Romanov, A. L. [Fermilab; Ruan, J. [Fermilab; Valishev, A. [Fermilab; Noll, D. [Frankfurt U.

    2015-06-01

    Recent developments in the study of integrable Hamiltonian systems have led to nonlinear accelerator lattice designs with two transverse invariants. These lattices may drastically improve the performance of high-power machines, providing wide tune spreads and Landau damping to protect the beam from instabilities, while preserving dynamic aperture. To test the feasibility of these concepts, the Integrable Optics Test Accelerator (IOTA) is being designed and built at Fermilab. One way to obtain a nonlinear integrable lattice is by using the fields generated by a magnetically confined electron beam (electron lens) overlapping with the circulating beam. The parameters of the required device are similar to the ones of existing electron lenses. We present theory, numerical simulations, and first design studies of electron lenses for nonlinear integrable optics.

  15. Application of gamma-ray radiography and gravimetric measurements after accelerated corrosion tests of steel embedded in mortar

    The accelerated corrosion by the impressed current technique is widely used in studies of concrete durability since it has the advantage that tests can be carried out within reasonable periods of time. In the present work the relationship between the applied current density and the resulting damage on the reinforcing steel, by applying optical microscopy, scanning electron microscopy, gamma-ray radiography and gravimetric measurements, was studied by means of the implementation of accelerated corrosion tests on reinforced mortar. The results show that the efficiency of the applied current is between 1 and 77%, regardless of the applied current density, the water/cement ratio and the mortar cover depth of the specimens. The results show the applicability of the gamma-ray radiography technique to detect localized corrosion of steel rebars in laboratory specimens

  16. Application of gamma-ray radiography and gravimetric measurements after accelerated corrosion tests of steel embedded in mortar

    Duffó, Gustavo, E-mail: duffo@cnea.gov.ar [Comisión Nacional de Energía Atómica, Gerencia Materiales, Depto. Corrosión, Av. Gral. Paz 1499, 1650 San Martín, Buenos Aires (Argentina); Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Rivadavia 1917, 1033 Buenos Aires (Argentina); Universidad Nacional de San Martín, Av. Gral. Paz 1499, 1650 San Martín, Buenos Aires (Argentina); Gaillard, Natalia [Universidad Nacional de San Martín, Av. Gral. Paz 1499, 1650 San Martín, Buenos Aires (Argentina); Mariscotti, Mario; Ruffolo, Marcelo [Tomografía de Hormigón Armado S.A. (THASA), Reclus 2017, 1609 Boulogne, Buenos Aires (Argentina)

    2015-08-15

    The accelerated corrosion by the impressed current technique is widely used in studies of concrete durability since it has the advantage that tests can be carried out within reasonable periods of time. In the present work the relationship between the applied current density and the resulting damage on the reinforcing steel, by applying optical microscopy, scanning electron microscopy, gamma-ray radiography and gravimetric measurements, was studied by means of the implementation of accelerated corrosion tests on reinforced mortar. The results show that the efficiency of the applied current is between 1 and 77%, regardless of the applied current density, the water/cement ratio and the mortar cover depth of the specimens. The results show the applicability of the gamma-ray radiography technique to detect localized corrosion of steel rebars in laboratory specimens.

  17. An Accelerated Test Method of Simultaneous Carbonation and Chloride Ion Ingress: Durability of Silica Fume Concrete in Severe Environments

    Ghahari, S. A.; Ramezanianpour, A. M.; Ramezanianpour, A. A.; Esmaeili, M

    2016-01-01

    The effects of simultaneous carbonation and chloride ion attack on mechanical characteristics and durability of concrete containing silica fume have been investigated through an accelerated test method. Specimens containing different amounts of silica fume were maintained in an apparatus in which carbon dioxide pressure and concentration and relative humidity were kept constant, and wetting and drying cycles in saline water were applied. Surface resistivity, sorptivity, CO2 consumption, and c...

  18. Testing prototypes of high-temperature superconducting current leads of cryogenic stand for testing magnetic elements of the NICA accelerating complex

    Kres, E. V.; Kadenko, I. N.; Bessheiko, O. A.; Belov, D. V.; Blinov, N. A.; Galimov, A. R.; Zorin, A. G.; Karpinsky, V. N.; Nikiforov, D. N.; Pivin, R. V.; Smirnov, A. V.; Shevchenko, E. V.; Smirnov, S. A.; Khodzhibagiyan, G. G.; Liu, Cheng Lian

    2014-09-01

    In the Laboratory of High Energies at the Joint Institute for Nuclear Research, as part of the NICA-MPD [1] project, tests of two prototypes of HTSC current leads prepared at ASIPP institute (Hefei, China) have been performed [2, 3] to measure electric and heat parameters and to search for structural and physical drawbacks. Based on the experimental results, necessary changes are made in the structure of HTSC current leads of the testing stand for the magnetic element testing of the NICA accelerating complex and its basic setups: the Nuclotron, Booster, and Collider.

  19. High power testing of the RF accelerating cavity for the positron damping ring at SuperKEKB

    A positron damping ring (DR) is under construction to meet the requirement of the low-emittance positron-beam injection to the main ring of SuperKEKB based on the nano-beam scheme. We have proposed and developed a radiofrequency (RF) accelerating structure for the DR, which can supply 2 MV accelerating voltage at maximum with three accelerating cavities to be installed in a limited space, forming “multi single cell” structure. This structure is based on the higher-order-mode (HOM) damped structure of the normal-conducting accelerating cavity system ARES, where 32 ARES cavities had been successfully operated at the KEKB main rings with extremely low trip rates. Last fiscal year, we made the first production-version cavity (hereafter called cavity No.1) based on the development of the prototype cavity (hereafter called prototype). In this paper, we present results of low-power and high-power tests of the cavity No.1, compared with the results of the prototype. (author)

  20. Optimal Design of Multiple Stresses Accelerated Life Test Plan Based on Transforming the Multiple Stresses to Single Stress

    GAO Liang; CHEN Wenhua; QIAN Ping; PAN Jun; HE Qingchuan

    2014-01-01

    For planning optimum multiple stresses accelerated life test plans, a commonly followed guiding principle is that all parameters of the life-stress relationship should be estimated, and the number of the stress level combinations must be no less than the number of parameters of the life-stress relationship. However, the general objective of an accelerated life test(ALT) is to assess thep-th quantile of the product life distribution under normal stress. For this objective,estimating all model parameters is not necessary, and this will increase the cost of test. Based on the theoretical conclusion that the stress level combinations of the optimum multiple stresses ALT plan locate on a straight line through the origin of coordinate, it is proposed that a design idea of planning the optimum multiple stresses ALT plan through transforming the problem of designing an optimum multiple stresses ALT plan to designing an optimum single stress ALT plan. Moreover, a method of planning the optimum multiple stresses ALT plan which can avoid estimating all model parameters is established. An example shows that, the proposed plan which only has two stress level combinations could achieve an accuracy no less than the traditional plan, and save the test time and cost on one stress level combination at least; when the actual product life is less than the design value, even the deviation of the model initial parameters value is up to 20%, the variance of the estimation of thep-th quantile of the proposed plan is still smaller than the traditional plans approximately 25%. A design method is provided for planning the optimum multiple stresses ALT which uses the statistical optimum degenerate test plan as the optimum multiple stresses accelerated life test plan.

  1. Cavity digital control testing system by Simulink step operation method for TESLA linear accelerator and free electron laser

    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.

  2. Parameters Optimization for a Novel Vacuum Laser Acceleration Test at BNL-ATF

    Shao, Lei; Zhou, Feng

    2005-01-01

    This paper presents a new VLA theory model which has revealed that the injection electrons with low energy and small incident angle relative to the laser beam are captured and significantly accelerated in a strong laser field. For the further step for verifying the novel-VLA mechanics, we propose to use the BNL-ATF Terawatt CO2 laser and a high-brightness electron beam to carry out a proof-of-principle beam experiment. Experiment setup including the laser injection optics and electron extraction system and beam diagnostics is presented. Extensive optimized simulation results with ATF practical parameters are also presented, which shows that even when the laser intensity is not very high, the net energy gain still can be seen obviously. This could be prospect for a new revolution of vacuum laser acceleration.

  3. Experimental design and analysis for accelerated degradation tests with Li-ion cells.

    Doughty, Daniel Harvey; Thomas, Edward Victor; Jungst, Rudolph George; Roth, Emanuel Peter

    2003-08-01

    This document describes a general protocol (involving both experimental and data analytic aspects) that is designed to be a roadmap for rapidly obtaining a useful assessment of the average lifetime (at some specified use conditions) that might be expected from cells of a particular design. The proposed experimental protocol involves a series of accelerated degradation experiments. Through the acquisition of degradation data over time specified by the experimental protocol, an unambiguous assessment of the effects of accelerating factors (e.g., temperature and state of charge) on various measures of the health of a cell (e.g., power fade and capacity fade) will result. In order to assess cell lifetime, it is necessary to develop a model that accurately predicts degradation over a range of the experimental factors. In general, it is difficult to specify an appropriate model form without some preliminary analysis of the data. Nevertheless, assuming that the aging phenomenon relates to a chemical reaction with simple first-order rate kinetics, a data analysis protocol is also provided to construct a useful model that relates performance degradation to the levels of the accelerating factors. This model can then be used to make an accurate assessment of the average cell lifetime. The proposed experimental and data analysis protocols are illustrated with a case study involving the effects of accelerated aging on the power output from Gen-2 cells. For this case study, inadequacies of the simple first-order kinetics model were observed. However, a more complex model allowing for the effects of two concurrent mechanisms provided an accurate representation of the experimental data.

  4. Setting accelerated dissolution test for PLGA microspheres containing peptide, investigation of critical parameters affecting drug release rate and mechanism.

    Tomic, I; Vidis-Millward, A; Mueller-Zsigmondy, M; Cardot, J-M

    2016-05-30

    The objective of this study was development of accelerated in vitro release method for peptide loaded PLGA microspheres using flow-through apparatus and assessment of the effect of dissolution parameters (pH, temperature, medium composition) on drug release rate and mechanism. Accelerated release conditions were set as pH 2 and 45°C, in phosphate buffer saline (PBS) 0.02M. When the pH was changed from 2 to 4, diffusion controlled phases (burst and lag) were not affected, while release rate during erosion phase decreased two-fold due to slower ester bonds hydrolyses. Decreasing temperature from 45°C to 40°C, release rate showed three-fold deceleration without significant change in release mechanism. Effect of medium composition on drug release was tested in PBS 0.01M (200 mOsm/kg) and PBS 0.01M with glucose (380 mOsm/kg). Buffer concentration significantly affected drug release rate and mechanism due to the change in osmotic pressure, while ionic strength did not have any effect on peptide release. Furthermore, dialysis sac and sample-and-separate techniques were used, in order to evaluate significance of dissolution technique choice on the release process. After fitting obtained data to different mathematical models, flow-through method was confirmed as the most appropriate for accelerated in vitro dissolution testing for a given formulation. PMID:27025293

  5. Atomic oxygen ground-based accelerated tests of spacecraft materials and structures for long-term LEO missions

    Chernik, Vladimir; Novikov, Lev; Smirnova, Tatyana; Shumov, Andrey

    Spacecraft materials are degradated during long-term low earth orbit (LEO) flight. The Internation Space Station (ISS) is planed to be prolonged the term of action up to 20-25 years. To specify so long life one requires a validation of spacecraft material behaviour conservation for the period. The LEO environment includes atomic oxygen (AO) destructive incident flow. The appropriate AO fluence is proposed to be as high as 10E22-10E23 atom O/sq cm. The simulative ground-based test is evident to be acceptable if its duration is not too long usually under several hundreds of hours. In that case the rate of the test acceleration exceeds 100-200. One way to accelerate test is to increase oxygen particles energy. We test materials under oxygen plasma beam, formed by a magnetoplasmadynamic accelerator, with the oxygen particle energy of 20 -30 eV. In this way we determine an AO effective fluence by a kapton equivalent technique. The beam varies from LEO incident flow by energy, flux and rates of the oxygen dissociation / ionization/ excitation. To evaluate the test adequacy we measured and compared with LEO data erosion yields of a number of polymer materials, applied on spacecraft external surfaces. There were: polyimide (kapton), polyamide (nylon), polyethylene, polyvinyl fluoride (tedlar), polysteren, polymethyl methacrylate, epoxy, polyethylene terephthalate (mylar), graphite. Their relative erosion yields, measured and normalized by polyimide in this way, practically coincide with the data of flight experiments on the ISS. The results ground to use our plasma mode for accelerated tests of spacecraft material durability for long-term LEO flights. We tested quite a number of polymer-based materials and structures usable on ISS and another LEO spacecrafts. The effective AO fluencies ran up to 3,5 10E22 atom O/sq cm corresponding to the ISS flight duration about 20 years. We studied material behaviors like mass and thickness losses, erosion yield, surface morphology

  6. Proton injector acceptance tests for a Dielectric Wall Accelerator (DWA):characterisation of Advanced Injection System of Light Ions (AISLI)

    Peng, S.X., E-mail: sxpeng@pku.edu.cn; Ren, H.T.; Xu, Y.; Zhang, T.; Zhao, J.; Zhang, A.L.; Guo, Z.Y.; Chen, J.E.

    2014-11-01

    To demonstrate the acceleration capability of a Dielectric Wall Accelerator (DWA), a proton injector has been developed at Peking University (PKU). It is composed of a compact permanent magnet 2.45 GHz Electron Cyclotron Resonance Ion Source (PKU PMECRIS) associated with a LEBT of two electrostatic Einzel lenses [1]. This injector is named as Advanced Injector System of Light Ions (AISLI). The acceptance tests have been performed with a 40 keV–55 mA hydrogen beam successfully passing through a ϕ 10 mm aperture diaphragm. This diaphragm is located 200 mm downstream the plasma emission hole at the location of the future DWA entrance flange. The beam rms emittance reached about 0.10 π mm mrad in pulsed mode. This article describes the AISLI experimental setup, the measurement principle and the obtained beam characteristics.

  7. Mechanical Design of a High Energy Beam Absorber for the Advanced Superconducting Test Accelerator (ASTA) at Fermilab

    Baffes, C; Leibfritz, J; Oplt, S; Rakhno, I

    2013-01-01

    A high energy beam absorber has been built for the Advanced Superconducting Test Accelerator (ASTA) at Fermilab. In the facility's initial configuration, an electron beam will be accelerated through 3 TTF-type or ILC-type RF cryomodules to an energy of 750MeV. The electron beam will be directed to one of multiple downstream experimental and diagnostic beam lines and then deposited in one of two beam absorbers. The facility is designed to accommodate up to 6 cryomodules, which would produce a 75kW beam at 1.5GeV; this is the driving design condition for the beam absorbers. The beam absorbers consist of water-cooled graphite, aluminum and copper layers contained in a Helium-filled enclosure. This paper describes the mechanical implementation of the beam absorbers, with a focus on thermal design and analysis. In addition, the potential for radiation-induced degradation of the graphite is discussed.

  8. Proton injector acceptance tests for a Dielectric Wall Accelerator (DWA):characterisation of Advanced Injection System of Light Ions (AISLI)

    To demonstrate the acceleration capability of a Dielectric Wall Accelerator (DWA), a proton injector has been developed at Peking University (PKU). It is composed of a compact permanent magnet 2.45 GHz Electron Cyclotron Resonance Ion Source (PKU PMECRIS) associated with a LEBT of two electrostatic Einzel lenses [1]. This injector is named as Advanced Injector System of Light Ions (AISLI). The acceptance tests have been performed with a 40 keV–55 mA hydrogen beam successfully passing through a ϕ 10 mm aperture diaphragm. This diaphragm is located 200 mm downstream the plasma emission hole at the location of the future DWA entrance flange. The beam rms emittance reached about 0.10 π mm mrad in pulsed mode. This article describes the AISLI experimental setup, the measurement principle and the obtained beam characteristics

  9. Mechanical Design of a High Energy Beam Absorber for the Advanced Superconducting Test Accelerator (ASTA) at Fermilab

    Baffes, C.; Church, M.; Leibfritz, J.; Oplt, S.; Rakhno, I.; /Fermilab

    2012-05-10

    A high energy beam absorber has been built for the Advanced Superconducting Test Accelerator (ASTA) at Fermilab. In the facility's initial configuration, an electron beam will be accelerated through 3 TTF-type or ILC-type SRF cryomodules to an energy of 750MeV. The electron beam will be directed to one of multiple downstream experimental and diagnostic beam lines and then deposited in one of two beam absorbers. The facility is designed to accommodate up to 6 cryomodules, which would produce a 75kW beam at 1.5GeV; this is the driving design condition for the beam absorbers. The beam absorbers consist of water-cooled graphite, aluminum and copper layers contained in a helium-filled enclosure. This paper describes the mechanical implementation of the beam absorbers, with a focus on thermal design and analysis. The potential for radiation-induced degradation of the graphite is discussed.

  10. Summary of Construction Activities and Results from Six Initial Accelerated Pavement Tests Conducted on Asphalt Concrete Pavement Section for Modified-Binder Overlay

    Bejarano, Manuel O.; Morton, Bruce S.; Scheffy, Clark

    2005-01-01

    This report summarizes the activities and data collected during the construction of a pavement section used for investigating the performance of asphalt concrete pavements under accelerated pavement testing. This report also presents the preliminary results of six accelerated pavement tests conducted on the test section. The pavement section was constructed in September 2001 at the Pavement Research Center, located at the University of California Richmond Field Station. The construct...

  11. Evaluation of life of insulator materials for electric wires by accelerated deterioration test due to radiation and heat

    From the viewpoint of the safe operation and the extension of life of nuclear power stations, the secular deterioration of the machinery and equipment which compose nuclear reactors has become the problem. Also electric wires and cables are the important components of nuclear reactors, and organic materials are used as the insulator materials, the secular deterioration is an unavoidable subject to be investigated. In electric wires and cables, the kinds of insulator and sheath materials are many, and the compositions are diversified, therefore it is very difficult to estimate their life from the past data. In this study, as for the polymer materials which have been widely used for electric wires, the accelerated test by applying radiation and heat to them was carried out, and the method for estimating the secular deterioration was investigated. The testing method and the results are reported. The materials put to the test were ethylene propylene rubber and polyethylene chlorosulfonate, and the samples were the sheets of 1 mm thickness. The tests by the simultaneous application of radiation and heat and the successive application were carried out. The rate of lowering of fracture elongation increased in proportion to the magnification of acceleration. (K.I.)

  12. Optimization of parameters for the inline-injection system at Brookhaven Accelerator Test Facility

    Parsa, Z. [Brookhaven National Lab., Upton, NY (United States); Ko, S.K. [Ulsan Univ. (Korea, Republic of)

    1995-10-01

    We present some of our parameter optimization results utilizing code PARMLEA, for the ATF Inline-Injection System. The new solenoid-Gun-Solenoid -- Drift-Linac Scheme would improve the beam quality needed for FEL and other experiments at ATF as compared to the beam quality of the original design injection system. To optimize the gain in the beam quality we have considered various parameters including the accelerating field gradient on the photoathode, the Solenoid field strengths, separation between the gun and entrance to the linac as well as the (type size) initial charge distributions. The effect of the changes in the parameters on the beam emittance is also given.

  13. Development of an accelerated pavement test reproducing the effect of natural ageing on skid resistance

    Kane, M.; D. Zhao; Chailleux, E.; Delarrard, F.; Do, M. T.

    2013-01-01

    This study deals with the development of a new test method simulating the effect of ageing on skid resistance. This test is applied to bituminous mixes in this study, but can also be applied to concrete. This test relies on two machines, the Wehner–Schulze machine, to measure the friction, and the Weatherometer sunset machine, to simulate weather effects (rain, wind, sunlight, etc.). The relevance of this test is evaluated from comparisons between changes in friction and a chemical func...

  14. Automated-process gas-chromatograph system for use in accelerated corrosion testing of HTGR core-support posts

    An automated-process gas chromatograph is the heart of a gaseous-impurities-analysis system developed for the Oak Ridge National Laboratory Core Support Performance Test, at which graphite core-support posts for high-temperature gas-cooled fission reactors are being subjected to accelerated corrosion tests under tightly controlled conditions of atmosphere and temperature. Realistic estimation of in-core corrosion rates is critically dependent upon the accurate measurement of low concentrations of CO, CO2, CH4, H2, and O2 in the predominantly helium atmosphere. In addition, the capital and labor investment associated with each test puts a premium upon the reliability of the analytical system, as excessive downtime or failure to obtain accurate data would result in unacceptable costs and schedule delays. After an extensive survey of available measurement techniques, gas chromatography was chosen for reasons of accuracy, flexibility, good-performance record, and cost

  15. In vitro evaluation of the bonding durability of self-adhesive resin cement to titanium using highly accelerated life test.

    Lin, Jie; Shinya, Akikazu; Gomi, Harunori; Matinlinna, Jukka Pekka; Shinya, Akiyoshi

    2011-01-01

    The purpose of this in vitro study was to evaluate the bonding durability of three self-adhesive resin cements to titanium using the Highly Accelerated Life Test (HALT). The following self-adhesive resin cements were used to bond pairs of titanium blocks together according to manufacturers' instructions: RelyX Unicem, Breeze, and Clearfil SA Luting. After storage in water at 37°C for 24 h, bonded specimens (n=15) immersed in 37°C water were subjected to cyclic shear load testing regimes of 20, 30, or 40 kg using a fatigue testing machine. Cyclic loading continued until failure occurred, and the number of cycles taken to reach failure was recorded. The bonding durability of a self-adhesive resin cement to titanium was largely influenced by the weight of impact load. HALT showed that Clearfil SA Luting, which contained MDP monomer, yielded the highest median bonding lifetime to titanium. PMID:22123007

  16. The erosion of the beaches on the coast of Alicante: Study of the mechanisms of weathering by accelerated laboratory tests.

    López, I; López, M; Aragonés, L; García-Barba, J; López, M P; Sánchez, I

    2016-10-01

    One of the main problems that coasts around the world present, is the regression and erosion of beaches. However, the factors involved in these processes are unclear. In this study, the influence of sediment erosion on beach regression has been analysed. In order to do that, a three-step investigation has been carried out. Firstly, coastline variations of four Spanish beaches have been analysed. Secondly, a study on sediment position along the beach profile has been developed. Finally, the process that beach sediments undergo along the surf zone when they are hit by the incident waves has been simulated by an accelerated particle weathering test. Samples of sand and shells were subjected to this accelerated particle weathering test. Results were supplemented with those from carbonate content test, XRD, SEM and granulometric analysis. Results shows a cross-shore classification of sediments along the beach profile in which finer particles move beyond offshore limit. Besides, it was observed that sediment erosion process is divided into three sages: i) particles wear due to crashes ii) dissolution of the carbonate fraction, and iii) breakage and separation of mineral and carbonate parts of particles. All these processes lead to a reduction of particle size. The mechanism responsible of beach erosion would consist of multiples and continuous particle location exchanges along the beach profile as a consequence of grain-size decrease due to erosion. PMID:27220096

  17. Bayesian estimation of the parameters of the bivariate generalized exponential distribution using accelerated life testing under censoring data

    Abd El-Maseh, M. P

    2015-11-01

    Full Text Available In this paper, the Bayesian estimation for the unknown parameters for the bivariate generalized exponential (BVGE distribution under Bivariate censoring type-I samples with constant stress accelerated life testing (CSALT are discussed. The scale parameter of the lifetime distribution at constant stress levels is assumed to be an inverse power law function of the stress level. The parameters are estimated by Bayesian approach using Markov Chain Monte Carlo (MCMC method based on Gibbs sampling. Then, the numerical studies are introduced to illustrate the approach study using samples which have been generated from the BVGE distribution.

  18. Performance Tests of Survey Instruments Used in Radiation Fields Around High-Energy Accelerators

    Mayer, Sabine; Fürstner, Markus; Menzel, Hans Gregor; Roesler, Stefan; Theis, Christian; Vincke, Helmut H

    2005-01-01

    Measurements of ambient dose equivalent in stray radiation fields behind the shielding of high-energy accelerators are a challenging task. Several radiation components (photons, neutrons, charged particles), spanning a wide range of energies, contribute to the total dose equivalent. In routine-measurements, the total dose equivalent is obtained by the combination of several radiation detectors. Ionisation chambers, which are sensitive to all radiation components, are employed together with so-called REM counters, which are responding mainly to neutrons. The total dose equivalent is correctly assessed provided that the response is interpreted carefully by using appropriate corrections and calibration factors. For this reason measurements were carried out in a high-energy reference field at CERN, which allows one to study the response of the different detectors in a mixed radiation field under controlled conditions. In addition, the field was simulated by Monte Carlo simulations. The outcome of these studies se...

  19. Redshift-drift as a test for discriminating between decelerating inhomogeneous and accelerating universe models

    Mishra, Priti; Singh, Tejinder P

    2013-01-01

    Exact inhomogeneous solutions of Einstein's equations have been used in the literature to build models reproducing the cosmological data without dark energy. However, owing to the degrees of freedom pertaining to these models, it is necessary to get rid of the degeneracy of ten exhibited by the problem of distinguishing between them and accelerating universe models. We give an overview of redshift drift in inhomogeneous cosmologies, and explain how it serves to this purpose. One class of models which fits the data is the Szekeres Swiss-cheese class where non-spherically symmetric voids exhibit a typical size of about 400 Mpc. We present our calculation of the redshift drift in this model, and compare it with the results obtained by other authors for alternate scenarios.

  20. Facility for Advanced Accelerator Experimental Tests at SLAC (FACET) Conceptual Design Report

    Amann, J.; Bane, K.; /SLAC

    2009-10-30

    This Conceptual Design Report (CDR) describes the design of FACET. It will be updated to stay current with the developing design of the facility. This CDR begins as the baseline conceptual design and will evolve into an 'as-built' manual for the completed facility. The Executive Summary, Chapter 1, gives an introduction to the FACET project and describes the salient features of its design. Chapter 2 gives an overview of FACET. It describes the general parameters of the machine and the basic approaches to implementation. The FACET project does not include the implementation of specific scientific experiments either for plasma wake-field acceleration for other applications. Nonetheless, enough work has been done to define potential experiments to assure that the facility can meet the requirements of the experimental community. Chapter 3, Scientific Case, describes the planned plasma wakefield and other experiments. Chapter 4, Technical Description of FACET, describes the parameters and design of all technical systems of FACET. FACET uses the first two thirds of the existing SLAC linac to accelerate the beam to about 20GeV, and compress it with the aid of two chicanes, located in Sector 10 and Sector 20. The Sector 20 area will include a focusing system, the generic experimental area and the beam dump. Chapter 5, Management of Scientific Program, describes the management of the scientific program at FACET. Chapter 6, Environment, Safety and Health and Quality Assurance, describes the existing programs at SLAC and their application to the FACET project. It includes a preliminary analysis of safety hazards and the planned mitigation. Chapter 7, Work Breakdown Structure, describes the structure used for developing the cost estimates, which will also be used to manage the project. The chapter defines the scope of work of each element down to level 3.

  1. A test of the nature of cosmic acceleration using galaxy redshift distortions.

    Guzzo, L; Pierleoni, M; Meneux, B; Branchini, E; Le Fèvre, O; Marinoni, C; Garilli, B; Blaizot, J; De Lucia, G; Pollo, A; McCracken, H J; Bottini, D; Le Brun, V; Maccagni, D; Picat, J P; Scaramella, R; Scodeggio, M; Tresse, L; Vettolani, G; Zanichelli, A; Adami, C; Arnouts, S; Bardelli, S; Bolzonella, M; Bongiorno, A; Cappi, A; Charlot, S; Ciliegi, P; Contini, T; Cucciati, O; de la Torre, S; Dolag, K; Foucaud, S; Franzetti, P; Gavignaud, I; Ilbert, O; Iovino, A; Lamareille, F; Marano, B; Mazure, A; Memeo, P; Merighi, R; Moscardini, L; Paltani, S; Pellò, R; Perez-Montero, E; Pozzetti, L; Radovich, M; Vergani, D; Zamorani, G; Zucca, E

    2008-01-31

    Observations of distant supernovae indicate that the Universe is now in a phase of accelerated expansion the physical cause of which is a mystery. Formally, this requires the inclusion of a term acting as a negative pressure in the equations of cosmic expansion, accounting for about 75 per cent of the total energy density in the Universe. The simplest option for this 'dark energy' corresponds to a 'cosmological constant', perhaps related to the quantum vacuum energy. Physically viable alternatives invoke either the presence of a scalar field with an evolving equation of state, or extensions of general relativity involving higher-order curvature terms or extra dimensions. Although they produce similar expansion rates, different models predict measurable differences in the growth rate of large-scale structure with cosmic time. A fingerprint of this growth is provided by coherent galaxy motions, which introduce a radial anisotropy in the clustering pattern reconstructed by galaxy redshift surveys. Here we report a measurement of this effect at a redshift of 0.8. Using a new survey of more than 10,000 faint galaxies, we measure the anisotropy parameter beta = 0.70 +/- 0.26, which corresponds to a growth rate of structure at that time of f = 0.91 +/- 0.36. This is consistent with the standard cosmological-constant model with low matter density and flat geometry, although the error bars are still too large to distinguish among alternative origins for the accelerated expansion. The correct origin could be determined with a further factor-of-ten increase in the sampled volume at similar redshift. PMID:18235494

  2. Results and comparison of seven accelerated cycling test procedures for the photovoltaic application

    Potteau, E.; Desmettre, D.; Mattera, F.; Bach, O.; Martin, J.-L.; Malbranche, P.

    Choosing the right battery for a given photovoltaic (PV) system is a key question, because it strongly influences the cost and reliability of the system. This paper presents results of seven test procedures experienced at the GENEC battery test facility. A set of four complementary tests is selected, covering the various types of photovoltaic systems. Moreover, the analysis of these results gives an estimation of the ageing rate for the different types of batteries used in photovoltaic systems.

  3. Methodology for designing accelerated aging tests for predicting life of photovoltaic arrays

    Gaines, G. B.; Thomas, R. E.; Derringer, G. C.; Kistler, C. W.; Bigg, D. M.; Carmichael, D. C.

    1977-01-01

    A methodology for designing aging tests in which life prediction was paramount was developed. The methodology builds upon experience with regard to aging behavior in those material classes which are expected to be utilized as encapsulant elements, viz., glasses and polymers, and upon experience with the design of aging tests. The experiences were reviewed, and results are discussed in detail.

  4. Development of Neural Network Model for Predicting Peak Ground Acceleration Based on Microtremor Measurement and Soil Boring Test Data

    T. Kerh

    2012-01-01

    Full Text Available It may not be possible to collect adequate records of strong ground motions in a short period of time; hence microtremor survey is frequently conducted to reveal the stratum structure and earthquake characteristics at a specified construction site. This paper is therefore aimed at developing a neural network model, based on available microtremor measurement and on-site soil boring test data, for predicting peak ground acceleration at a site, in a science park of Taiwan. The four key parameters used as inputs for the model are soil values of the standard penetration test, the medium grain size, the safety factor against liquefaction, and the distance between soil depth and measuring station. The results show that a neural network model with four neurons in the hidden layer can achieve better performance than other models presently available. Also, a weight-based neural network model is developed to provide reliable prediction of peak ground acceleration at an unmeasured site based on data at three nearby measuring stations. The method employed in this paper provides a new way to treat this type of seismic-related problem, and it may be applicable to other areas of interest around the world.

  5. A modified PMMA cement (Sub-cement) for accelerated fatigue testing of cemented implant constructs using cadaveric bone.

    Race, Amos; Miller, Mark A; Mann, Kenneth A

    2008-10-20

    Pre-clinical screening of cemented implant systems could be improved by modeling the longer-term response of the implant/cement/bone construct to cyclic loading. We formulated bone cement with degraded fatigue fracture properties (Sub-cement) such that long-term fatigue could be simulated in short-term cadaver tests. Sub-cement was made by adding a chain-transfer agent to standard polymethylmethacrylate (PMMA) cement. This reduced the molecular weight of the inter-bead matrix without changing reaction-rate or handling characteristics. Static mechanical properties were approximately equivalent to normal cement. Over a physiologically reasonable range of stress-intensity factor, fatigue crack propagation rates for Sub-cement were higher by a factor of 25+/-19. When tested in a simplified 2 1/2-D physical model of a stem-cement-bone system, crack growth from the stem was accelerated by a factor of 100. Sub-cement accelerated both crack initiation and growth rate. Sub-cement is now being evaluated in full stem/cement/femur models. PMID:18774136

  6. Accelerated Degradation Test and Predictive Failure Analysis of B10 Copper-Nickel Alloy under Marine Environmental Conditions

    Bo Sun

    2015-09-01

    Full Text Available This paper studies the corrosion behavior of B10 copper-nickel alloy in marine environment. Accelerated degradation test under marine environmental conditions was designed and performed based on the accelerated testing principle and the corrosion degradation mechanism. With the prolongation of marine corrosion time, the thickness of Cu2O film increased gradually. Its corrosion product was Cu2(OH3Cl, which increased in quantity over time. Cl− was the major factor responsible for the marine corrosion of copper and copper alloy. Through the nonlinear fitting of corrosion rate and corrosion quantity (corrosion weight loss, degradation data of different corrosion cycles, the quantitative effects of two major factors, i.e., dissolved oxygen (DO and corrosion medium temperature, on corrosion behavior of copper alloy were analyzed. The corrosion failure prediction models under different ambient conditions were built. One-day corrosion weight loss under oxygenated stirring conditions was equivalent to 1.31-day weight loss under stationary conditions, and the corrosion rate under oxygenated conditions was 1.31 times higher than that under stationary conditions. In addition, corrosion medium temperature had a significant effect on the corrosion of B10 copper sheet.

  7. Liquid nitrogen tests of a Torus coil for the Jefferson Lab 12GeV accelerator upgrade

    Fair, Ruben J. [JLAB; Ghoshal, Probir K. [JLAB; Bruhwel, Krister B. [JLAB; Kashy, David H. [JLAB; Machie, Danny [JLAB; Bachimanchi, Ramakrishna [JLAB; Taylor, William; Fischer, John W. [JLAB; Legg, Robert A. [JLAB; Powers, Jacob R. [JLAB

    2015-06-01

    A magnet system consisting of six superconducting trapezoidal racetrack-type coils is being built for the Jefferson Lab 12-GeV accelerator upgrade project. The magnet coils are wound with Superconducting Super Collider-36 NbTi strand Rutherford cable soldered into a copper channel. Each superconducting toroidal coil is force cooled by liquid helium, which circulates in a tube that is in good thermal contact with the inside of the coil. Thin copper sheets are soldered to the helium cooling tube and enclose the superconducting coil, providing cooling to the rest of the coil pack. As part of a rigorous risk mitigation exercise, each of the six coils is cooled with liquid nitrogen (LN2) to 80 K to validate predicted thermal stresses, verify the robustness and integrity of electrical insulation, and evaluate the efficacy of the employed conduction cooling method. This paper describes the test setup, the tests performed, and the findings.

  8. Investigation of the cut-edge corrosion of organically-coated galvanized steel after accelerated atmospheric corrosion test

    Reşit Yıldız

    2015-11-01

    Full Text Available The cut edge corrosion of organically coated (epoxy, polyurethane and polyester galvanized steel was investigated using electrochemical impedance spectroscopy (EIS. Measurements were performed on specimens that had been tested in an accelerated atmospheric corrosion test. The samples were subjected to 10 s fogging and 1 h awaiting cycles in an exposure cabinet (120 and 180 days with artificial acid rain solution. According to the investigation, the coatings were damaged from the cut edge into the sheet, this distance was about 0.8 cm. These defects were more pronounced at after 180 days in proportion to after 120 days.

  9. Simulation of tunable Infra-Red Free-Electron Laser based on Test Linac of Pohang Accelerator Laboratory

    We have investigated the possibility of tunable Infrared Free-Electron Laser with Test Linac of Pohang Accelerator Laboratory through one dimensional simulation which includes energy spread and space charge effects and 3-D particle simulation that ingnores space charge force but takes into account the energy spread and the emittance of the electron beam and the diffraction of the electromagnetic wave. The enhanced current density of the Test Linac makes it feasible to amplify the 4.2 kW signal of 10.6 μm radiation to 200 MW level. Extending the design parameters, electron beam energy (20-60 MeV), wiggler field strength (around 3 kG), and radiation wavelength (10-90 μm), we have revealed the requisites for the design of the tunable radiation source and the expected gains in that frequency range. It is shown to generate more than 100 MW in the tunable range. (author)

  10. Beam steering: A Test bench for generic algorithms in accelerator controls

    The operation of a complex accelerator system such as LEP or the future LHC at CERN demands automatic and standard controls to make it easy to use and reliable in all circumstances. A class of beam manipulations is the steering in the various machines and transfer channels. An algorithm has been devised to satisfy the required condition of genericity. It is based on a least squares method and yields a correction system which is not necessarily well conditioned in a usual operational environment where correctors and monitors may be either missing or redundant. The algorithm has been coded in Mathematica and implemented in the CERN PS control system. It is called through the MathLink protocol by an application program linked to standard beam position measurement software. With this technique, the development of the algorithm and its linkage to the control system are fully de-coupled. The application will become generic as soon as the magnetic and optical parameters will be loaded in data bases

  11. Measuring test mass acceleration noise in space-based gravitational wave astronomy

    Congedo, Giuseppe

    2014-01-01

    The basic constituent of interferometric gravitational wave detectors -- the test mass to test mass interferometric link -- behaves as a differential dynamometer measuring effective differential forces, comprising an integrated measure of gravity curvature, inertial effects, as well as non-gravitational spurious forces. This last contribution is going to be characterised by the LISA Pathfinder mission, a technology precursor of future space-borne detectors like eLISA. Changing the perspective...

  12. Microwave power coupler for a superconducting multiple-cell cavity for accelerator application and its testing procedures

    Li, Jianjian; /IIT, Chicago

    2008-12-01

    Superconducting cavity resonators offer the advantage of high field intensity for a given input power, making them an attractive contender for particle accelerator applications. Power coupling into a superconducting cavity employed in a particle accelerator requires unique provisions to maintain high vacuum and cryogenic temperature on the cavity side, while operating with ambient conditions on the source side. Components introduced to fulfill mechanical requirements must show negligible obstruction of the propagation of the microwave with absence of critical locations that may give rise to electron multipaction, leading to a multiple section design, instead of an aperture, a probe, or a loop structure as found in conventional cavities. A coaxial power coupler for a superconducting multiple-cell cavity at 3.9 GHz has been developed. The cavity is intended to be employed as an accelerator to provide enhanced electron beam quality in a free-electron laser in Hamburg (FLASH) user facility. The design of the coupler called for two windows to sustain high vacuum in the cavity and two bellows to accommodate mechanical dimensional changes resulting from cryogenics. Suppression of multipacting was accomplished by the choice of conductor dimensions and materials with low second yield coefficients. Prior to integration with the cavity, the coupler was tested for intrinsic properties in a back-to-back configuration and conditioned for high-power operation with increasing power input. Maximum incident power was measured to be 61 kW. When integrated with the superconducting cavity, a loaded quality factor of 9 x 10{sup 5} was measured by transient method. Coupler return loss and insertion loss were estimated to be around -21 dB and -0.2 dB, respectively.

  13. THE MECHANICAL AND SHIELDING DESIGN OF A PORTABLE SPECTROMETER AND BEAM DUMP ASSEMBLY AT BNLS ACCELERATOR TEST FACILITY

    A portable assembly containing a vertical-bend dipole magnet has been designed and installed immediately down-beam of the Compton electron-laser interaction chamber on beamline 1 of the Accelerator Test Facility (ATF) at Brookhaven National Laboratory (BNL). The water-cooled magnet designed with field strength of up to 0.7 Tesla will be used as a spectrometer in the Thompson scattering and vacuum acceleration experiments, where field-dependent electron scattering, beam focusing and energy spread will be analyzed. This magnet will deflect the ATF's 60 MeV electron-beam 90o downward, as a vertical beam dump for the Compton scattering experiment. The dipole magnet assembly is portable, and can be relocated to other beamlines at the ATF or other accelerator facilities to be used as a spectrometer or a beam dump. The mechanical and shielding calculations are presented in this paper. The structural rigidity and stability of the assembly were studied. A square lead shield surrounding the assembly's Faraday Cup was designed to attenuate the radiation emerging from the 1 inch-copper beam stop. All photons produced were assumed to be sufficiently energetic to generate photoneutrons. A safety evaluation of groundwater tritium contamination due to the thermal neutron capturing by the deuterium in water was performed, using updated Monte Carlo neutron-photon coupled transport code (MCNP). High-energy neutron spallation, which is a potential source to directly generate radioactive tritium and sodium-22 in soil, was conservatively assessed in verifying personal and environmental safety

  14. Planning the research and development necessary for accelerator transmutation of waste, leading to integrated proof of performance testing

    The Research and Development (R and D) Plan for the Accelerator Transmutation of Waste (ATW) Program has been developed for the Department of Energy, Office of Nuclear Energy (DOE/NE) to serve as a focus and progressional guide in developing critical transmutation technologies. It is intended that the Plan will serve as a logical reference considering all elements of an integrated accelerator-driven transmutation system, and will maximize the use of resources by identifying and prioritizing research, design, development and trade activities. The R and D Plan provides a structured framework for identifying and prioritizing activities leading to technically-justifiable integrated Proof of Performance testing within ten years and ultimate demonstration of Accelerator Transmutation of Waste (ATW). The Plan builds from the decision objectives specified for ATW, utilizes informational input from the ATW Roadmap and programmatic System Point Design efforts, and employs the knowledge and expertise provided by professionals familiar with ATW technologies. With the firm intent of understanding what, why and when information is needed, including critical interfaces, the Plan then develops a progressional strategy for developing ATW technologies with the use of a Technology Readiness Level (TRL) scale. The TRL approach is first used to develop a comprehensive, yet generic, listing of experimental, analytical and trade study activities critical to developing ATW technologies. Technology-specific and concept-specific aspects are then laid over the generic mapping to gage readiness levels. Prioritization criteria for reducing technical uncertainty, providing information to decision points, and levering off of international collaborations are then applied to focus analytical, experimental and trade activities. (author)

  15. MO-F-16A-01: Implementation of MPPG TPS Verification Tests On Various Accelerators

    Purpose: To demonstrate the implementation of the Medical Physics Practice Guideline (MPPG) for dose calculation and beam parameters verification of treatment planning systems (TPS). Methods: We implemented the draft TPS MPPG for three linacs: Varian Trilogy, TomoHDA and Elekta Infinity. Static and modulated test plans were created. The static fields are different than used in commissioning. Data was collected using ion chambers and diodes in a scanning water tank, Delta4 phantom and a custom phantom. MatLab and Microsoft Excel were used to create analysis tools to compare reference DICOM dose with scan data. This custom code allowed for the interpolation, registration and gamma analysis of arbitrary dose profiles. It will be provided as open source code. IMRT fields were validated with Delta4 registration and comparison tools. The time for each task was recorded. Results: The tests confirmed the strengths, and revealed some limitations, of our TPS. The agreement between calculated and measured dose was reported for all beams. For static fields, percent depth dose and profiles were analyzed with criteria in the draft MPPG. The results reveal areas of slight mismatch with the model (MLC leaf penumbra, buildup region.) For TomoTherapy, the IMRT plan 2%/2 mm gamma analysis revealed poorest agreement in the low dose regions. For one static test plan for all 10MV Trilogy photon beams, the plan generation, scan queue creation, data collection, data analysis and report took 2 hours, excluding tank setup. Conclusions: We have demonstrated the implementation feasibility of the TPS MPPG. This exercise generated an open source tool for dose comparisons between scan data and DICOM dose data. An easily reproducible and efficient infrastructure with streamlined data collection was created for repeatable robust testing of the TPS. The tests revealed minor discrepancies in our models and areas for improvement that are being investigated

  16. MO-F-16A-01: Implementation of MPPG TPS Verification Tests On Various Accelerators

    Smilowitz, J; Bredfeldt, J; Geurts, M; Miller, J [University of Wisconsin, Madison, WI (United States)

    2014-06-15

    Purpose: To demonstrate the implementation of the Medical Physics Practice Guideline (MPPG) for dose calculation and beam parameters verification of treatment planning systems (TPS). Methods: We implemented the draft TPS MPPG for three linacs: Varian Trilogy, TomoHDA and Elekta Infinity. Static and modulated test plans were created. The static fields are different than used in commissioning. Data was collected using ion chambers and diodes in a scanning water tank, Delta4 phantom and a custom phantom. MatLab and Microsoft Excel were used to create analysis tools to compare reference DICOM dose with scan data. This custom code allowed for the interpolation, registration and gamma analysis of arbitrary dose profiles. It will be provided as open source code. IMRT fields were validated with Delta4 registration and comparison tools. The time for each task was recorded. Results: The tests confirmed the strengths, and revealed some limitations, of our TPS. The agreement between calculated and measured dose was reported for all beams. For static fields, percent depth dose and profiles were analyzed with criteria in the draft MPPG. The results reveal areas of slight mismatch with the model (MLC leaf penumbra, buildup region.) For TomoTherapy, the IMRT plan 2%/2 mm gamma analysis revealed poorest agreement in the low dose regions. For one static test plan for all 10MV Trilogy photon beams, the plan generation, scan queue creation, data collection, data analysis and report took 2 hours, excluding tank setup. Conclusions: We have demonstrated the implementation feasibility of the TPS MPPG. This exercise generated an open source tool for dose comparisons between scan data and DICOM dose data. An easily reproducible and efficient infrastructure with streamlined data collection was created for repeatable robust testing of the TPS. The tests revealed minor discrepancies in our models and areas for improvement that are being investigated.

  17. Timing control of a high voltage pulse deflector to stabilize EUV laser light at the SCSS test accelerator

    A high-voltage pulse deflector cuts out a single bunch beam of 1 ns from a long beam pulse of more than 2 μs generated with a single crystal thermionic gun at the SCSS test accelerator. In order to realize a stable EUV laser, we should precisely control the deflector gate timing, which determines a beam arrival time at a 238-MHz pre-buncher cavity. Unfortunately, the deflector timing system was not enough for our requirement in an early stage, because the gate timing drifted due to a temperature change of a timing module. In addition, machine operators of the accelerator often manually had to tune the gate timing for the stable machine operation. To ameliorate this situation, we improved the timing monitor system of the high-voltage pulse passing through the deflector strip line. The detail of the improvements were exchanging an IC in a level converter module to improve a temperature coefficient and replacing a manual delay line with a remote control one. We also introduced a PID control system using the remote control delay line to automatically stabilize the timing. At the result, the stability of the EUV laser is not affected by the deflector gate timing anymore. (author)

  18. An RF Waveguide Distribution System for the ILC Test Accelerator at Fermilab's NML

    An ILC R and D facility is being constructed in the NML building at Fermilab which, in addition to an injector and beam dump with spectrometer, will contain up to three cryomodules of ILC-type superconducting 9-cell cavities. This linac will be powered by a single klystron. As part of SLAC's contribution to this project, we will provide a distribution network in WR650 waveguide to the various cavity couplers. In addition to commercial waveguide components and circulators and loads, this system will include adjustable tap-offs, and customized hybrids. In one configuration, the circulators will be removed to test pair-wise cancellation of cavity reflections through hybrids. The system will be pressurized with nitrogen to 3 bar absolute to avoid the need for SF6. The full distribution system for the first cryomodule will be delivered and installed later this year. We describe the design of the system and completed RF testing

  19. Development of an Accelerated Test Method for the Determination of Susceptibility to Atmospheric Corrosion

    Ambrose, John R.

    1991-01-01

    The theoretical rationale is presented for use of a repetitive cyclic current reversal voltammetric technique for characterization of localized corrosion processes, including atmospheric corrosion. Applicability of this proposed experimental protocol is applied to characterization of susceptibility to crevice and pitting corrosion, atmospheric corrosion and stress corrosion cracking. Criteria upon which relative susceptibility is based were determined and tested using two iron based alloys commonly in use at NASA-Kennedy; A36 (a low carbon steel) and 4130 (a low alloy steel). Practicality of the procedure was demonstrated by measuring changes in anodic polarization behavior during high frequency current reversal cycles of 25 cycles per second with 1 mA/sq cm current density amplitude in solutions containing Cl anions. The results demonstrated that, due to excessive polarization which affects conductivity of barrier corrosion product layers, A36 was less resistant to atmospheric corrosion than its 4130 counterpart; behavior which was also demonstrated during exposure tests.

  20. Ethylene propylene cable degradation during LOCA research tests: tensile properties at the completion of accelerated aging

    Six ethylene-propylene rubber (EPR) insulation materials were aged at elevated temperature and radiation stress exposures common in cable LOCA qualification tests. Material samples were subjected to various simultaneous and sequential aging simulations in preparation for accident environmental exposures. Tensile properties subsequent to the aging exposure sequences are reported. The tensile properties of some, but not all, specimens were sensitive to the order of radiation and elevated temperature stress exposure. Other specimens showed more severe degradation when simultaneously exposed to radiation and elevated temperature as opposed to the sequential exposure to the same stresses. Results illustrate the difficulty in defining a single test procedure for nuclear safety-related qualification of EPR elastomers. A common worst-case sequential aging sequence could not be identified

  1. On the compressibility effect in test particle acceleration by magnetohydrodynamic turbulence

    C.A. González; Dmitruk, P.; Mininni, P.D.; Matthaeus, W. H.

    2016-01-01

    The effect of compressibility in charged particle energization by magnetohydrodynamic (MHD) fields is studied in the context of test particle simulations. This problem is relevant to the solar wind and the solar corona due to the compressible nature of the flow in those astrophysical scenarios. We consider turbulent electromagnetic fields obtained from direct numerical simulations of the MHD equations with a strong background magnetic field. In order to explore the compressibilty effect over ...

  2. Neural Network Models of Simple Mechanical Systems Illustrating the Feasibility of Accelerated Life Testing

    Fusaro, Robert L.; Jones, Steven P.; Jansen, Ralph

    1996-01-01

    A complete evaluation of the tribological characteristics of a given material/mechanical system is a time-consuming operation since the friction and wear process is extremely systems sensitive. As a result, experimental designs (i.e., Latin Square, Taguchi) have been implemented in an attempt to not only reduce the total number of experimental combinations needed to fully characterize a material/mechanical system, but also to acquire life data for a system without having to perform an actual life test. Unfortunately, these experimental designs still require a great deal of experimental testing and the output does not always produce meaningful information. In order to further reduce the amount of experimental testing required, this study employs a computer neural network model to investigate different material/mechanical systems. The work focuses on the modeling of the wear behavior, while showing the feasibility of using neural networks to predict life data. The model is capable of defining which input variables will influence the tribological behavior of the particular material/mechanical system being studied based on the specifications of the overall system.

  3. Vacuum seals design and testing for a linear accelerator of the National Spallation Neutron Source

    Z. Chen; C. Gautier; F. Hemez; N. K. Bultman

    2000-02-01

    Vacuum seals are very important to ensure that the Spallation Neutron Source (SNS) Linac has an optimum vacuum system. The vacuum joints between flanges must have reliable seals to minimize the leak rate and meet vacuum and electrical requirements. In addition, it is desirable to simplify the installation and thereby also simplify the maintenance required. This report summarizes an investigation of the metal vacuum seals that include the metal C-seal, Energized Spring seal, Helcoflex Copper Delta seal, Aluminum Delta seal, delta seal with limiting ring, and the prototype of the copper diamond seals. The report also contains the material certifications, design, finite element analysis, and testing for all of these seals. It is a valuable reference for any vacuum system design. To evaluate the suitability of several types of metal seals for use in the SNS Linac and to determine the torque applied on the bolts, a series of vacuum leak rate tests on the metal seals have been completed at Los Alamos Laboratory. A copper plated flange, using the same type of delta seal that was used for testing with the stainless steel flange, has also been studied and tested. A vacuum seal is desired that requires significantly less loading than a standard ConFlat flange with a copper gasket for the coupling cavity assembly. To save the intersegment space the authors use thinner flanges in the design. The leak rate of the thin ConFlat flange with a copper gasket is a baseline for the vacuum test on all seals and thin flanges. A finite element analysis of a long coupling cavity flange with a copper delta seal has been performed in order to confirm the design of the long coupling cavity flange and the welded area of a cavity body with the flange. This analysis is also necessary to predict a potential deformation of the cavity under the combined force of atmospheric pressure and the seating load of the seal. Modeling of this assembly has been achieved using both HKS/Abaqus and COSMOS

  4. Vacuum seals design and testing for a linear accelerator of the National Spallation Neutron Source

    Vacuum seals are very important to ensure that the Spallation Neutron Source (SNS) Linac has an optimum vacuum system. The vacuum joints between flanges must have reliable seals to minimize the leak rate and meet vacuum and electrical requirements. In addition, it is desirable to simplify the installation and thereby also simplify the maintenance required. This report summarizes an investigation of the metal vacuum seals that include the metal C-seal, Energized Spring seal, Helcoflex Copper Delta seal, Aluminum Delta seal, delta seal with limiting ring, and the prototype of the copper diamond seals. The report also contains the material certifications, design, finite element analysis, and testing for all of these seals. It is a valuable reference for any vacuum system design. To evaluate the suitability of several types of metal seals for use in the SNS Linac and to determine the torque applied on the bolts, a series of vacuum leak rate tests on the metal seals have been completed at Los Alamos Laboratory. A copper plated flange, using the same type of delta seal that was used for testing with the stainless steel flange, has also been studied and tested. A vacuum seal is desired that requires significantly less loading than a standard ConFlat flange with a copper gasket for the coupling cavity assembly. To save the intersegment space the authors use thinner flanges in the design. The leak rate of the thin ConFlat flange with a copper gasket is a baseline for the vacuum test on all seals and thin flanges. A finite element analysis of a long coupling cavity flange with a copper delta seal has been performed in order to confirm the design of the long coupling cavity flange and the welded area of a cavity body with the flange. This analysis is also necessary to predict a potential deformation of the cavity under the combined force of atmospheric pressure and the seating load of the seal. Modeling of this assembly has been achieved using both HKS/Abaqus and COSMOS

  5. Characterization of electron clouds in the Cornell Electron Storage Ring Test Accelerator using TE-wave transmission

    De Santis, S.; Byrd, J. M.; Billing, M.; Palmer, M.; Sikora, J.; Carlson, B.

    2010-01-02

    A relatively new technique for measuring the electron cloud density in storage rings has been developed and successfully demonstrated [S. De Santis, J.M. Byrd, F. Caspers, A. Krasnykh, T. Kroyer, M.T.F. Pivi, and K.G. Sonnad, Phys. Rev. Lett. 100, 094801 (2008).]. We present the experimental results of a systematic application of this technique at the Cornell Electron Storage Ring Test Accelerator. The technique is based on the phase modulation of the TE mode transmitted in a synchrotron beam pipe caused by the periodic variation of the density of electron plasma. Because of the relatively simple hardware requirements, this method has become increasingly popular and has been since successfully implemented in several machines. While the principles of this technique are straightforward, quantitative derivation of the electron cloud density from the measurement requires consideration of several effects, which we address in detail.

  6. Numerical Investigation of a Cascaded Longitudinal Space-Charge Amplifier at the Fermilab's Advanced Superconducting Test Accelerator

    Halavanau, A. [NICADD, DeKalb; Piot, P. [NICADD, DeKalb

    2015-06-01

    In a cascaded longitudinal space-charge amplifier (LSCA), initial density noise in a relativistic e-beam is amplified via the interplay of longitudinal space charge forces and properly located dispersive sections. This type of amplification process was shown to potentially result in large final density modulations [1] compatible with the production of broadband electromagnetic radiation. The technique was recently demonstrated in the optical domain [2]. In this paper we investigate, via numerical simulations, the performances of a cascaded LSCA beamline at the Fermilab’s Advanced Superconducting Test Accelerator (ASTA). We especially explore the properties of the produced broadband radiation. Our studies have been conducted with a grid-less three-dimensional space-charge algorithm.

  7. ESTIMATION OF PARAMETERS IN STEP-STRESS ACCELERATED LIFE TESTS FOR THE RAYLEIGH DISTRIBUTION UNDER CENSORING SETUP

    N. Chandra

    2014-12-01

    Full Text Available In this paper, step-stress accelerated life test strategy is considered in obtaining the failure time data of the highly reliable items or units or equipment in a specified period of time. It is assumed that life time data of such items follows a Rayleigh distribution with a scale parameter (θ which is the log linear function of the stress levels. The maximum likelihood estimates (MLEs of the scale parameters ( i θ at both the stress levels (s , i = 2,1 i are obtained under a cumulative exposure model. A simulation study is performed to assess the precision of the MLEs on the basis of mean square error (MSE and relative absolute bias (RABias. The coverage probabilities of approximate and bootstrap confidence intervals for the parameters involved under both the censoring setup are numerically examined. In addition to this, asymptotic variance and covariance matrix of the estimators are also presented.

  8. ANALYSIS OF ACCELERATED LIFE TESTING USING LOG-LOGISTIC GEOMETRIC PROCESS MODEL IN CASE OF CENSORED DATA

    S. SAXENA

    2013-07-01

    Full Text Available Geometric process model has been used in a variety of situations such as the determination of the optimal replacement policy and the optimal inspection-repair replacement policy for standby systems, and the analysis of data with trends. This study deals with the analysis of accelerated life testing for Log-Logistic distribution using geometric process model. The case of type-I censoring is considered in this study. It is assumed that the lifetimes under increasing stress levels form a geometric process. The maximum likelihood estimates of the parameters and their confidence intervals using the asymptotic method are derived. The performance of the estimators is evaluated by a simulation study with different pre-fixed parameters.

  9. Accelerator mass spectrometry for tests of the Pauli exclusion principle and for detection of ββ decay products

    Three experiments with accelerator mass spectrometry (AMS) are described. (1) The cross section of the reaction 60Ni(n,2n)59Ni with 14.8 MeV neutrons was measured with AMS to be 410 ± 100 mb in agreement with the predictions of calculations. On the basis of a radioactivity measurement of 59Ni performed for the same reaction by another group, a half-life of 290.000 ± 100.000 y was deduced for 59Ni. (2) Tests of the Pauli exclusion principle were performed by looking for non-Paulian atoms with three electrons in the K shell and for non-Paulian nuclei with three protons or three neutrons in the nuclear 1 s1/2 shell. (3) The feasibility of radiochemical ββ decay experiments with AMS are considered. EC-EC decay products could be detected. Detection limits and the construction of the ion source are discussed. (author)

  10. Test results of a small-sized linear accelerator of 2.5 MeV electrons for custom examination of freight

    Test results of a small-sized linear accelerator of 2.5 MeV electrons with local radiation shield are presented. The accelerator is intended for the movable facilities of radiation custom examination. Results of measuring the dose and dose rate stability, uniformity and symmetry of the dose field, boundary energy of Bremsstrahlung, size and position of the focal spot, and also radiation leakage are given

  11. Accelerated test for PE 100 and PE 100 RC pipes grades

    Nezbedová, E.; Hutař, Pavel; Knésl, Zdeněk; Sadílek, J.

    Halle-Wittenberg : Martin Luther University, 2010 - (Michler, G.), s. 1-6 ISBN 978-3-86829-282-4. [Polymeric Materials 2010. Halle/Saale (DE), 15.09.2010-17.09.2010] R&D Projects: GA ČR GA106/08/1409; GA ČR GC101/09/J027; GA ČR GA106/09/0279 Institutional research plan: CEZ:AV0Z20410507 Keywords : HDPE * PENT test * COD Subject RIV: JL - Materials Fatigue, Friction Mechanics

  12. Application of the accelerated test Rancimat to evaluate oxidative stability of dried microencapsulated oils

    Márquez-Ruiz, G.

    2000-08-01

    Full Text Available The objective of this work was to apply the oxidative test Rancimat to dried microencapsulated oils (DMO, with special emphasis on assessing the efficacy of natural antioxidants. DMO were prepared by freeze-drying emulsions containing sodium caseinate, lactose and fish or sunflower oils, with and without added the antioxidant mixture ALT (ascorbic acid, lecithin and tocopherol. Under the Rancimat working conditions selected for testing DMO (5 g sample, 100ºC and 20 L air/h, excellent repeatability was obtained. The antioxidant effect of ALT was much higher in bulk fish oil than in its counterpart DMO, either in Rancimat or at 30ºC in the dark. Further experiments using Rancimat showed that the moderate increase in stability of DMO added ALT was only attributable to tocopherol while the synergistic actions of lecithin and ascorbic acid were not observed, their action probably depending on their location and orientation in these complex lipid systems. This test enabled to compare monophasic (bulk oils and DMO-extracted oils and heterophasic lipidic systems (DMO and DMO devoid of the accessible, free oil fraction, thus offering a rapid means to examine the influence of oil distribution and partitioning of antioxidants on oxidative stability.El objetivo de este trabajo es la aplicación del test Rancimat a aceites microencapsulados, con especial interés en el estudio de la eficacia de antioxidantes naturales. Los aceites microencapsulados en matriz seca (DMO se prepararon mediante liofilización de emulsiones constituidas por caseinato sódico, lactosa y aceite de pescado o girasol, con o sin la mezcla antioxidante ALT (ácido ascórbico, lecitina y tocoferol. En las condiciones seleccionadas en Rancimat (5 g de muestra, 100ºC y 20 L/h aire se obtuvo excelente repetitividad. La mezcla ALT fue mucho más efectiva en el aceite de pescado que en su correspondiente DMO, tanto en Rancimat como a 30ºC en la oscuridad. Otros experimentos en

  13. Search for major genes with progeny test data to accelerate the development of genetically superior loblolly pine

    NCSU

    2003-12-30

    This research project is to develop a novel approach that fully utilized the current breeding materials and genetic test information available from the NCSU-Industry Cooperative Tree Improvement Program to identify major genes that are segregating for growth and disease resistance in loblolly pine. If major genes can be identified in the existing breeding population, they can be utilized directly in the conventional loblolly pine breeding program. With the putative genotypes of parents identified, tree breeders can make effective decisions on management of breeding populations and operational deployment of genetically superior trees. Forest productivity will be significantly enhanced if genetically superior genotypes with major genes for economically important traits could be deployed in an operational plantation program. The overall objective of the project is to develop genetic model and analytical methods for major gene detection with progeny test data and accelerate the development of genetically superior loblolly pine. Specifically, there are three main tasks: (1) Develop genetic models for major gene detection and implement statistical methods and develop computer software for screening progeny test data; (2) Confirm major gene segregation with molecular markers; and (3) Develop strategies for using major genes for tree breeding.

  14. Design and beam tests of an RFQ to accelerate a lead ion beam from a laser ion source

    A Radio Frequency Quadrupole (RFQ) for acceleration of a 10 mA lead 18+ ion beam from 6.9 keV/u to 100 keV/u has been designed, built and tested in the framework of the CERN Laser Ion Source (LIS) study. The challenge of the RFQ design was to deal with a lead ion beam that includes about 10 charge states with an overall current of some 100 mA. A new RFQ design, intermediate between the two standard high-intensity and low-intensity designs, has been applied in order to have a compact structure giving small longitudinal emittance and high transmission. The transport and matching line from the source to the RFQ is made of two solenoids. The unwanted charge states are not filtered and will enter the RFQ mis-matched. In order to test the RFQ performance proper it was decided to operate it with an equivalent mono-species proton beam during the first stage of the commissioning. The design criteria for this intermediate current RFQ, the problems involved in dealing with a mixture of different charge states, as well as the results of the first test with an equivalent proton beam are presented in this paper. (author)

  15. The influence of the curing conditions of concrete on durability after freeze-thaw accelerated testing

    Al-Assadi, G.

    2015-12-01

    Full Text Available This work relates the curing conditions of concrete with the damage caused by rapid freeze-thaw cycles (ASTM C 666. The “potential” durability of concrete after testing is also studied. In countries with a continental climate, the curing of concrete in summer is performed under high-temperature and low-humidity conditions, and during the winter the concrete undergoes freezing and thawing. This paper shows the experimental results of the behaviour of concrete specimens cured under climatic summer conditions and then subjected to freeze-thaw cycles. Curing of the specimens includes conditions of good and bad practice in relation to wetting and protection of the concrete. Mechanical properties, cement hydration, volume and pore sizes, oxygen permeability, chloride diffusion and water penetration under pressure tests of the concrete are assessed. These tests were performed before and after the application of the freeze-thaw cycles. Statistical analysis of the correlation among variables is also included.Este trabajo relaciona las condiciones de curado del hormigón con los daños causados por ciclos hielo-deshielo (ASTM C 666. Estudia la durabilidad “potencial” del hormigón dañado por este ensayo. En países con clima continental, el curado del hormigón en verano se realiza con alta temperatura y baja humedad, y durante el invierno sufre condiciones de hielo-deshielo. Se presentan los resultados experimentales de probetas de hormigón curadas bajo condiciones climáticas del verano y luego sometidas a ciclos hielo-deshielo. El curado de las probetas incluye condiciones de buenas y malas prácticas en relación con el curado del hormigón. Se miden las propiedades mecánicas, grado de hidratación, volumen de poros y distribución de tamaños, permeabilidad al oxígeno, penetración de agua bajo presión y coeficiente de difusión de cloruros antes y después de la aplicación de los ciclos de hielo-deshielo. Se incluye un estudio estad

  16. The Next Linear Collider Test Accelerator's RF Pulse Compression And Transmission Systems

    The overmoded rf transmission and pulsed power compression system for SLAC's Next Linear Collider (NLC) program requires a high degree of transmission efficiency and mode purity to be economically feasible. To this end, a number of new, high power components and systems have been developed at X-band, which transmit rf power in the low loss, circular TE01 mode with negligible mode conversion. In addition, a highly efficient SLED-II* pulse compressor has been developed and successfully tested at high power. The system produced a 200 MW, 250 ns wide pulse with a near-perfect flat-top. In this paper we describe the design and test results of the high power pulse compression system using SLED-II. The NLC rf systems use low loss highly over-moded circular waveguides operating in the TE01 mode. The efficiency of the systems is sensitive to the mode purity of the mode excited inside these guides. We used the so called flower petal mode transducer (2) to excite the TE01 mode. This type of mode transducer is efficient, compact and capable of handling high levels of power. To make more efficient systems, we modified this device by adding several mode selective chokes to act as mode purifiers. To manipulate the rf signals we used these modified mode converters to convert back and forth between over-moded circular waveguides and single-moded WR90 rectangular waveguides. Then, we used the relatively simple rectangular waveguide components to do the actual manipulation of rf signals. For example, two mode transducers and a mitered rectangular waveguide bend comprise a 90 degree bend. Also, a magic tee and four mode transducers would comprise a four-port-hybrid, etc. We will discuss the efficiency of an rf transport system based on the above methodology. We also used this methodology in building the SLEDII pulse compression system. At SLAC we built 4 of these pulse systems. In this paper we describe the SLEDII system and compare the performance of these 4 systems at SLAC. We

  17. Time-resolved beam-profile measurements on the Experimental Test Accelerator (ETA)

    Examples are given of time-resolved beam profiles measured on ETA using several techniques. One method uses a Faraday cup that is remotely movable in two-transverse dimensions (x, y). In another method a small diameter wire or pellet target is moved across the beam and the bremsstrahlung x-ray intensity is plotted. Data for these methods are recorded using a Tektronix 7912 digitizer at 16 equally spaced times during 50 ns. Three other methods use a time gated (4 ns) microchannel plate television camera to record a two-dimensional image of the beam intensity on a single pulse. The light sources used for imaging are: Cherenkov light from a Kapton foil, prompt visible light from a titanium foil and radiated light from gas molecules excited by the beam. We are also testing an x-ray pinhole camera using K/sub α/ x-rays from tungsten

  18. Toward a mechanistic understanding of the damage evolution of SnAgCu solder joints in accelerated thermal cycling test

    Mahin Shirazi, Sam

    Accelerated thermal cycling (ATC) tests are the most commonly used tests for the thermo-mechanical performance assessment of microelectronics assemblies. Currently used reliability models have failed to incorporate the microstructural dependency of lead free solder joint behavior and its microstructure evolution during cycling. Thus, it is essential to have a mechanistic understanding of the effect of cycling parameters on damage evolution and failure of lead free solder joints in ATC. Recrystallization has been identified as the damage rate controlling mechanism in ATC. Usually it takes 1/3 of life for completion of recrystallization regardless of cycling parameters. Thus, the life of the solder joints can be predicted by estimating global recrystallization. The objective of the first part of the study was to examine whether the damage scenario applies in service is the same as the harsh thermal cycling tests (i.e. 0/100 °C and -40/125 °C) commonly used in industry. Microstructure analysis results on a variety of lead free solder SnAgCu assemblies subjected to the both harsh (0/100 °C) and mild (20/80 °C) ATC confirmed similar failure mechanism under the both testing conditions. Sn grain morphology (interlaced versus beach ball) has a significant effect on the thermo-mechanical performance (and thus the model) of the lead free solder joints. The longer thermal cycling lifetime observed in the interlaced solder joints subjected to the ATC compared to the beach ball structure was correlated to the different initial microstructure and the microstructure evolution during cycling. For the modeling proposes, the present study was focused on Sn-Ag-Cu solder joints with either a single Sn grain or beach ball structure. Microstructural analysis results of the simulated thermal cycling experiment revealed that, the life can be approximated as determined by the accumulation of a certain amount of work during the high temperature dwells. Finally the effect of precipitates

  19. Evaluation of solder joint reliability in flip-chip packages during accelerated testing

    Kim, Jong-Woong; Kim, Dae-Gon; Hong, Won Sik; Jung, Seung-Boo

    2005-12-01

    The microstructural investigation and thermomechanical reliability evaluation of the Sn-3.0Ag-0.5Cu solder bumped flip-chip package were carried out during the thermal shock test of the package. In the initial reaction, the reaction product between the solder and Cu mini bump of chip side was Cu6Sn5 intermetallic compound (IMC) layer, while the two phases which were (Cu,Ni)6Sn5 and (Ni,Cu)3Sn4 were formed between the solder and electroless Ni-P layer of the package side. The cracks occurred at the corner solder joints after the thermal shocks of 400 cycles. The primary failure mechanism of the solder joints in this type of package was confirmed to be thermally-activated solder fatigue failure. The premature brittle interfacial failure sometimes occurred in the package side, but nearly all of the failed packages showed the occurrence of the typical fatigue cracks. The finite-element analyses were conducted to interpret the failure mechanisms of the packages, and revealed that the cracks were induced by the accumulation of the plastic work and viscoplastic shear strains.

  20. Tests of an environmental and personnel safe cleaning process for BNL accelerator and storage ring components

    A large measure of the successful operation of the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory (BNL) for over a decade can be attributed to the cleaning of its UHV components during and after construction. A new UHV cleaning process, which had to be environmentally and personnel safe, was needed to replace the harsh, unfriendly process which was still in use. Dow Advanced Cleaning Systems was contracted to develop a replacement process without the use of harsh chemicals and which must clean vacuum surfaces as well as the existing process. Acceptance of the replacement process was primarily based on Photon Stimulated Desorption (PSD) measurements of beam tube samples run on NSLS beam line U10B. One meter long beam tube samples were fabricated from aluminum, 304 stainless steel and oxygen free copper. Initially, coupon samples were cleaned and passed preliminary testing for the proposed process. Next, beam tube samples of each material were cleaned, and the PSD measured on beam line U10B using white light with a critical energy of 487 ev. Prior to cleaning, the samples were contaminated with a mixture of cutting oils, lubricants, vacuum oils and vacuum grease. The contaminated samples were then baked. Samples of each material were also cleaned with the existing process after the same preparation. Beam tube samples were exposed to between 1022 and 1023 photons per meter for a PSD measurement. Desorption yields for H2, CO, CO2, CH4 and H2O are reported for both the existing cleaning and for the replacement cleaning process. Preliminary data, residual gas scans, and PSD results are given and discussed. The new process is also compared with new cleaning methods developed in other laboratories

  1. COLLISIONLESS SHOCKS IN A PARTIALLY IONIZED MEDIUM. I. NEUTRAL RETURN FLUX AND ITS EFFECTS ON ACCELERATION OF TEST PARTICLES

    Blasi, P.; Morlino, G.; Bandiera, R.; Amato, E. [INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi, 5, I-50125 Firenze (Italy); Caprioli, D. [Department of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08540 (United States)

    2012-08-20

    A collisionless shock may be strongly modified by the presence of neutral atoms through the processes of charge exchange between ions and neutrals and ionization of the latter. These two processes lead to exchange of energy and momentum between charged and neutral particles both upstream and downstream of the shock. In particular, neutrals that suffer a charge exchange downstream with shock-heated ions generate high-velocity neutrals that have a finite probability of returning upstream. These neutrals might then deposit heat in the upstream plasma through ionization and charge exchange, thereby reducing the fluid Mach number. A consequence of this phenomenon, which we refer to as the neutral return flux, is a reduction of the shock compression factor and the formation of a shock precursor upstream. The scale length of the precursor is determined by the ionization and charge-exchange interaction lengths of fast neutrals moving toward upstream infinity. In the case of a shock propagating in the interstellar medium, the effects of ion-neutral interactions are especially important for shock velocities <3000 km s{sup -1}. Such propagation velocities are common among shocks associated with supernova remnants, the primary candidate sources for the acceleration of Galactic cosmic rays. We then investigate the effects of the return flux of neutrals on the spectrum of test particles accelerated at the shock. We find that, for shocks slower than {approx}3000 km s{sup -1}, the particle energy spectrum steepens appreciably with respect to the naive expectation for a strong shock, namely, {proportional_to}E{sup -2}.

  2. LED照明产品加速衰减试验方法研究%Accelerated Luminous Depreciation Testing for LED Lighting Products

    钱诚; 孙博; 曹峻松

    2014-01-01

    With the application of energy-saving, environmental and durable LED lighting products, the reliability testing has become a pivot point for the large scale industrialization and popularization. The paper briefly introduces two methods to be respectively applied in the accelerated depreciation testing for the luminous flex of LED lighting products and the life of outdoor LED-driving power, which can sharply shorten the time for lifetime test, providing references for the LED lighting products’ reliability evaluation.

  3. The Conversion of CESR to Operate as the Test Accelerator, CesrTA, Part 4: Superconducting Wiggler Diagnostics

    Billing, M. G.; Greenwald, S.; Liu, X.; Li, Y.; D. Sabol; Smith, E. N.; Strohman, C. R.; Palmer, M. A.; Munson, D.V.

    2016-01-01

    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 appropriate 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 ...

  4. Effect of TiO2-Crystal Forms on the Photo-Degradation of EVA/PLA Blend Under Accelerated Weather Testing

    Van Cong, Do; Trang, Nguyen Thi Thu; Giang, Nguyen Vu; Lam, Tran Dai; Hoang, Thai

    2016-05-01

    Photo-degradation of poly (ethylene-co-vinyl acetate) (EVA)/poly (lactic acid) (PLA) blend and EVA/PLA/TiO2 nanocomposites was carried out under accelerated weather testing conditions by alternating cycles of ultraviolet (UV) light and moisture at controlled and elevated temperatures. The characters, properties, and morphology of these materials before and after accelerated weather testing were determined by Fourier transform infrared spectroscopy, colour changes, viscosity, tensile test, thermogravimetric analysis, and field emission scanning electron microscopy. The increases in the content of oxygen-containing groups, colour changes; the decreases in viscosity, tensile properties, and thermal stability of these materials after accelerated weather testing are the evidence for the photo-degradation of the blend and nanocomposites. After accelerated weather testing, the appearance of many micro-holes and micro-pores on the surface of the collected samples was observed. The photo-degradation degree of the nanocomposites depended on the TiO2-crystal form. Rutile TiO2 do not enhance the degradation, but anatase and mixed crystals TiO2 nanoparticles promoted the degradation of the nanocomposites. Particularly, the mixed crystals TiO2 nanoparticles showed the highest photo-catalytic activity of the nanocomposites.

  5. An Accelerated Test Method of Simultaneous Carbonation and Chloride Ion Ingress: Durability of Silica Fume Concrete in Severe Environments

    S. A. Ghahari

    2016-01-01

    Full Text Available The effects of simultaneous carbonation and chloride ion attack on mechanical characteristics and durability of concrete containing silica fume have been investigated through an accelerated test method. Specimens containing different amounts of silica fume were maintained in an apparatus in which carbon dioxide pressure and concentration and relative humidity were kept constant, and wetting and drying cycles in saline water were applied. Surface resistivity, sorptivity, CO2 consumption, and carbonation and chloride ion ingress depths measurements were taken. Phase change due to carbonation and chloride ion attack was monitored by XRD analysis, and microstructures and interfacial transition zones were studied by implementing SEM as well as mercury intrusion porosimetry. It was expected to have a synergistic effect in the tidal zone where simultaneous carbonation and chloride ion attack happen. However, the observed reduced surface resistivity, compared to specimens maintained in CO2 gas, could be due to the moisture that is available near the surface, hindering CO2 from penetrating into the pores of the specimens. Moreover, the porosity analysis of the specimens showed that the sample containing silica fume cured in the tidal zone had 50.1% less total porosity than the plain cement paste cured in the same condition.

  6. Observation of Electron Cloud Instabilities and Emittance Dilution at the Cornell Electron-Positron Storage Ring Test Accelerator

    Electron cloud related emittance dilution and instabilities of bunch trains limit the performance of high intensity circular colliders. One of the key goals of the Cornell electron-positron storage ring Test Accelerator (CesrTA) research program is to improve our understanding of how the electron cloud alters the dynamics of bunches within the train. Single bunch beam diagnotics have been developed to measure the beam spectra, vertical beam size, two important dynamical effects of beams interacting with the electron cloud, for bunch trains on a turn-by-turn basis. Experiments have been performed at CesrTA to probe the interaction of the electron cloud with stored positron bunch trains. The purpose of these experiments was to characterize the dependence of beam-electron cloud interactions on the machine parameters such as bunch spacing, vertical chromaticity, and bunch current. The beam dynamics of the stored beam, in the presence of the electron cloud, was quantified using: 1) a gated beam position monitor (BPM) and spectrum analyzer to measure the bunch-by-bunch frequency spectrum of the bunch trains; 2) an x-ray beam size monitor to record the bunch-by-bunch, turn-by-turn vertical size of each bunch within the trains. In this paper we report on the observations from these experiments and analyze the effects of the electron cloud on the stability of bunches in a train under many different operational conditions

  7. Observation of Electron Cloud Instabilities and Emittance Dilution at the Cornell Electron-Positron Storage Ring Test Accelerator

    Holtzapple, R. L.; Billing, M. G.; Campbell, R. C.; Dugan, G. F.; Flanagan, J.; McArdle, K. E.; Miller, M. I.; Palmer, M. A.; Ramirez, G. A.; Sonnad, K. G.; Totten, M. M.; Tucker, S. L.; Williams, H. A.

    2016-04-01

    Electron cloud related emittance dilution and instabilities of bunch trains limit the performance of high intensity circular colliders. One of the key goals of the Cornell electron-positron storage ring Test Accelerator (CesrTA) research program is to improve our understanding of how the electron cloud alters the dynamics of bunches within the train. Single bunch beam diagnotics have been developed to measure the beam spectra, vertical beam size, two important dynamical effects of beams interacting with the electron cloud, for bunch trains on a turn-by-turn basis. Experiments have been performed at CesrTA to probe the interaction of the electron cloud with stored positron bunch trains. The purpose of these experiments was to characterize the dependence of beam-electron cloud interactions on the machine parameters such as bunch spacing, vertical chromaticity, and bunch current. The beam dynamics of the stored beam, in the presence of the electron cloud, was quantified using: 1) a gated beam position monitor (BPM) and spectrum analyzer to measure the bunch-by-bunch frequency spectrum of the bunch trains; 2) an x-ray beam size monitor to record the bunch-by-bunch, turn-by-turn vertical size of each bunch within the trains. In this paper we report on the observations from these experiments and analyze the effects of the electron cloud on the stability of bunches in a train under many different operational conditions.

  8. Quick Preparation of Moisture-Saturated Carbon Fiber-Reinforced Plastics and Their Accelerated Ageing Tests Using Heat and Moisture

    Masao Kunioka

    2016-06-01

    Full Text Available A quick method involving the control of heat and water vapor pressure for preparing moisture-saturated carbon fiber-reinforced plastics (CFRP, 8 unidirectional prepreg layers, 1.5 mm thickness, epoxy resin has been developed. The moisture-saturated CFRP sample was obtained at 120 °C and 0.2 MPa water vapor in 72 h by this method using a sterilizer (autoclave. The bending strength and viscoelastic properties measured by a dynamic mechanical analysis (DMA remained unchanged during repetitive saturation and drying steps. No degradation and molecular structural change occurred. Furthermore an accelerated ageing test with two ageing factors, i.e., heat and moisture was developed and performed at 140–160 °C and 0.36–0.62 MPa water vapor pressure by using a sealed pressure-proof stainless steel vessel (autoclave. The bending strength of the sample decreased from 1107 to 319 MPa at 160 °C and 0.63 MPa water vapor pressure in 9 days. Degraded samples were analyzed by DMA. The degree of degradation for samples was analyzed by DMA. CFRP and degraded CFRP samples were analyzed by using a surface and interfacial cutting analysis system (SAICAS and an electron probe micro-analyzer (EPMA equipped in a scanning electron microscope.

  9. Teste de envelhecimento precoce para sementes de azevém, aveia preta e milheto Accelerated aging test for ryegrass black oat grass and pearl millet seeds

    Danton Camacho Garcia

    1999-06-01

    Full Text Available A viabilidade da aplicação e da padronização do teste de envelhecimento precoce em sementes de azevém, aveia preta e milheto foi verificada em três lotes, para cada espécie, com valores iniciais de germinação semelhantes. As sementes de cada lote foram submetidas ao teste por períodos de 24, 48, 72, 96 e 120 horas, à temperatura de 41°C e 100% de umidade relativa do ar. Em aveia preta, o período de 24 horas estratifica lotes de sementes pelo vigor. Para milheto e azevém, o período de envelhecimento para estratificar lotes de sementes pelo vigor pode ser de 24 a 48 horas. Períodos de 72 a 120 horas são muito drásticos para as três espécies e impedem a estratificação de lotes de sementes pelo vigor.Accelerated aging test standardization for seeds of ryegrass, black oat grass and pearl millet was cheked in three lots, of each specie, with similar initial values of germination. The seeds of each lot were submited to periods of 24, 48, 96 and 120 hours of temperature of 41°C and air relative humidity of 100%. In black oat grass the 24h period stratifies seed vigor among lots. However, for pearl millet and ryegrass the period can be of 24 to 48h. Periods of 72 to 120 hours are very severe to the three species and prevent the seed vigor lots stratification.

  10. A study of the ASR of an aggregate with high chert content by means of ultra-accelerated mortar bar test and pore fluid analysis

    Larbi, J.A.; Visser, J.H.M.

    2002-01-01

    Various studies have indicated that the use of some ultra-accelerated mortar bar expansion test methods for assessing the alkali-silica reactivity of concrete aggregates (particularly those using 1 M NaOH solution at 80 oC) can give rise to misleading results causing certain types of aggregates to b

  11. A stand for simulation and test of the magnetic components of the focus beam and transport systems for accelerator LUE-200, installation IREN

    Technical parameters and physical abilities of the equipment stand for simulation and testing of the dipole electromagnet to focus and transport the beam of the linear accelerator (LUE-200) are described. The overall design of the stand, a description of the magnetometer and the positioning system of Hall sensors are presented. The software of the stand has been developed

  12. Final Report on "Development and Testing of Advanced Accelerator Structures and Technologies at 11.424 GHz"

    Gold, Steven H. [Naval Research Laboratory

    2013-10-13

    This is the final report on the research program ?Development and Testing of Advanced Accelerator Structures and Technologies at 11.424 GHz,? which was carried out by the Naval Research Laboratory (NRL) under Interagency Agreement DE?AI02?01ER41170 with the Department of Energy. The period covered by this report is 15 July 2010 ? 14 July 2013. The program included two principal tasks. Task 1 involved a study of the key physics issues related to the use of high gradient dielectric-loaded accelerating (DLA) structures in rf linear accelerators and was carried out in collaboration with Argonne National Laboratory (ANL) and Euclid Techlabs LLC. Task 2 involved a study of high power active microwave pulse compressors and was carried out in collaboration with Omega-P, Inc. and the Institute of Applied Physics of the Russian Academy of Sciences in Nizhny Novgorod. The studies under Task 1 were focused on rf-induced multipactor and breakdown in externally driven DLA structures at the 200-ns timescale. Suppression of multipactor and breakdown are essential to the practical application of dielectric structures in rf linear accelerators. The structures that were studied were developed by ANL and Euclid Techlabs and their performance was evaluated at high power in the X-band Magnicon Laboratory at NRL. Three structures were designed, fabricated, and tested, and the results analyzed in the first two years of the program: a clamped quartz traveling-wave (TW) structure, a externally copper-coated TW structure, and an externally copper-coated dielectric standing-wave (SW) structure. These structures showed that rf breakdown could be largely eliminated by eliminating dielectric joints in the structures, but that the multipactor loading was omnipresent. In the third year of the program, the focus of the program was on multipactor suppression using a strong applied axial magnetic field, as proposed by Chang et al. [C. Chang et al., J. Appl. Phys. 110, 063304 (2011).], and a

  13. 导弹加速寿命试验及可靠性评估%Accelerated Life Test and Reliability Evaluation of Missile

    宋贵宝; 崔加鑫

    2016-01-01

    相对于导弹的常规贮存寿命试验,加速寿命试验可以提高试验效率,节省试验成本,具有很好的军事和经济效益。论文针对导弹部组件多、结构复杂,加速寿命试验难度大的问题,提出了通过对薄弱环节进行加速寿命试验推出导弹贮存寿命的方法,给出了加速寿命试验的基本流程和设计方案,并介绍了基于极大似然估计法的导弹可靠性评估方法。最后以弹上某电子部件为例,开展了加速寿命试验,并对试验数据进行评估,得出了导弹的贮存寿命。%Relative to conventional storage life test of missile ,accelerated life test can improve the test efficiency and save test cost ,has the very good military and economic benefits .In this paper ,aiming at the problem that missile has many units ,complex structure ,accelerated life test is difficult ,a method for accelerating the storage life of a missile is presented , which is based on the accelerated life test of the weak links .The basic processes and design of the accelerated life test are giv‐en ,and the method of missile reliability assessment based on the method of maximum likelihood estimation is introduced .Fi‐nally the paper takes an example of an electronic component on the missile ,and conducts accelerated life test ,and assess the test data ,obtains the storage life of the missile .

  14. Betatron radiation based diagnostics for plasma wakefield accelerated electron beams at the SPARC_LAB test facility

    Shpakov, V.; Anania, M. P.; Biagioni, A.; Chiadroni, E.; Cianchi, A.; Curcio, A.; Dabagov, S.; Ferrario, M.; Filippi, F.; Marocchino, A.; Paroli, B.; Pompili, R.; Rossi, A. R.; Zigler, A.

    2016-09-01

    Recent progress with wake-field acceleration has shown a great potential in providing high gradient acceleration fields, while the quality of the beams remains relatively poor. Precise knowledge of the beam size at the exit from the plasma and matching conditions for the externally injected beams are the key for improvement of beam quality. Betatron radiation emitted by the beam during acceleration in the plasma is a powerful tool for the transverse beam size measurement, being also non-intercepting. In this work we report on the technical solutions chosen at SPARC_LAB for such diagnostics tool, along with expected parameters of betatron radiation.

  15. Stochastic shock response spectrum decomposition method based on probabilistic definitions of temporal peak acceleration, spectral energy, and phase lag distributions of mechanical impact pyrotechnic shock test data

    Hwang, James Ho-Jin; Duran, Adam

    2016-08-01

    Most of the times pyrotechnic shock design and test requirements for space systems are provided in Shock Response Spectrum (SRS) without the input time history. Since the SRS does not describe the input or the environment, a decomposition method is used to obtain the source time history. The main objective of this paper is to develop a decomposition method producing input time histories that can satisfy the SRS requirement based on the pyrotechnic shock test data measured from a mechanical impact test apparatus. At the heart of this decomposition method is the statistical representation of the pyrotechnic shock test data measured from the MIT Lincoln Laboratory (LL) designed Universal Pyrotechnic Shock Simulator (UPSS). Each pyrotechnic shock test data measured at the interface of a test unit has been analyzed to produce the temporal peak acceleration, Root Mean Square (RMS) acceleration, and the phase lag at each band center frequency. Maximum SRS of each filtered time history has been calculated to produce a relationship between the input and the response. Two new definitions are proposed as a result. The Peak Ratio (PR) is defined as the ratio between the maximum SRS and the temporal peak acceleration at each band center frequency. The ratio between the maximum SRS and the RMS acceleration is defined as the Energy Ratio (ER) at each band center frequency. Phase lag is estimated based on the time delay between the temporal peak acceleration at each band center frequency and the peak acceleration at the lowest band center frequency. This stochastic process has been applied to more than one hundred pyrotechnic shock test data to produce probabilistic definitions of the PR, ER, and the phase lag. The SRS is decomposed at each band center frequency using damped sinusoids with the PR and the decays obtained by matching the ER of the damped sinusoids to the ER of the test data. The final step in this stochastic SRS decomposition process is the Monte Carlo (MC

  16. Theoretical and experimental study of a modular accelerating structure of travelling waves sections for high gradient tests (MECCANO)

    A modular system, MECCANO, has been developed at the Laboratoire de l'Accelerateur Lineaire d'Orsay to study the physical and technical phenomena of high electric fields in travelling waves structures in the context of future linear colliders which can reach TeV energies. The behaviour of the electric field inside the section MECCANO is considered from the theoretical point of view with numerical simulations and analytical representations and from the experimental side with low and high power measurements. An infinite and uniform structure is classically described by series of RLC resonant circuits. The basic RF properties of the fundamental mode are given. For a finite section, the matching of a forward or backward travelling wave of any phase advance per cell is also represented by means of RLC circuits. The variations of the reflection and transmission properties of the structure with frequency and a new procedure to match couplers have been modelled and experimentally verified. The electromagnetic behaviour of each cavity and of the whole structure have been studied, the fundamental and first high order modes have been simulated by 2D or 3D codes and measured at low power. The matching of the phase, the amplitude and the reflection level of the accelerator is described. This procedure is found to be extremely delicate due to the abrupt changes in the geometry of the cavities. The structure has been tested at fields superior to 150 MV/m. The behaviour of some materials and surface layers subject to high gradients are presented. (author)

  17. Accelerated carbonation test of sprayed concrete%喷射混凝土快速碳化试验研究

    马蕊; 牛荻涛; 王家滨

    2014-01-01

    In order to investigate the carbonation resistance of sprayed concrete and the mechanical property after carbonation ,the accel-erated carbonation test was carried out.The results indicated that the carbonation resistance of sprayed concrete was superior to the normal. With the increasing of carbonation depth,compressive strength and splitting tensile strength of sprayed concrete grew rapidly.The admix-ing of steel fiber can further improve the carbonation resistance,reduce the carbonation rate,and increase the splitting tensile strength of sprayed concrete greatly.Besides,based on analyzing the effects of shotcrete technology and carbonation resistance of steel fiber admixing to sprayed concrete,a carbonation depth model for sprayed concrete was established.%通过快速碳化试验,探讨了喷射混凝土抗碳化性能和碳化后力学性能变化规律。试验结果表明:喷射混凝土较普通混凝土具有更好的抗碳化性能,其抗压强度、劈拉强度随碳化深度的增加快速提高;掺入钢纤维能进一步提高喷射混凝土碳化性能,减小碳化速率,还能显著提高喷射混凝土碳化后劈拉强度。同时,在分析钢纤维和施工方式对混凝土碳化影响的基础上,建立了喷射混凝土碳化深度模型。

  18. Beam Dynamics Studies and the Design, Fabrication and Testing of Superconducting Radiofrequency Cavity for High Intensity Proton Accelerator

    Saini, Arun [Univ. of Delhi, New Delhi (India)

    2012-03-01

    The application horizon of particle accelerators has been widening significantly in recent decades. Where large accelerators have traditionally been the tools of the trade for high-energy nuclear and particle physics, applications in the last decade have grown to include large-scale accelerators like synchrotron light sources and spallation neutron sources. Applications like generation of rare isotopes, transmutation of nuclear reactor waste, sub-critical nuclear power, generation of neutrino beams etc. are next area of investigation for accelerator scientific community all over the world. Such applications require high beam power in the range of few mega-watts (MW). One such high intensity proton beam facility is proposed at Fermilab, Batavia, US, named as Project-X. Project-X facility is based on H- linear accelerator (linac), which will operate in continuous wave (CW) mode and accelerate H- ion beam with average current of 1 mA from kinetic energy of 2.5 MeV to 3 GeV to deliver 3MW beam power. One of the most challenging tasks of the Project-X facility is to have a robust design of the CW linac which can provide high quality beam to several experiments simultaneously. Hence a careful design of linac is important to achieve this objective.

  19. Envelhecimento acelerado como teste de vigor para sementes de milho e soja Accelerated aging as test of vigor for corn and soybean seeds

    Alek Sandro Dutra

    2004-06-01

    control program and the accelerated aging test an important procedure for that. This work was carried out in order to search for specific methodologies of evaluation of seed vigor, in laboratory, based on the accelerated aging test. The research was conducted using six seed lots of corn and soybean species, with commercially accepted quality patterns (germination. The prior established conditions for aging were 42ºC/96h and 45ºC/72h for corn and 41ºC/48 and 72h and 42ºC/48 and 72h for soybean. For each combination of temperature and aging periods, the seeds were placed into plastic boxes (gerbox, with 40mL of distilled water, distributed on the screen, using single layer and based on the seed weight. For the aging, two chamber types, BOD and water jacketed were used. The moisture content and germination of seed lots, after aging, were determined. The water uptake considering the combinations of temperature/exposure period, the two chamber types and the two procedures of determining seed moisture content was higher when the seeds were conditioned in a single layer compared to weight (constant mass. For the corn, the combination of 45ºC/72h with the conditioning of the seeds in only layer was the most efficient method for the separation of the lots with relationship to the vigor. For soybean, the combination 42ºC/48h was more efficient in the separation of the lots, not having interference of the method of conditioning of the seeds, in the screen. Considering the results it can be concluded that the single layer distribution should be used for corn and soybean and the BOD chambers should also be used for accelerated aging test for both species.

  20. Status and test conditions of the klystron 5045 (SLAC) modulator for the LUE-200 accelerator of the IREN plant (FLNP, JINR)

    In the FLNP, JINR there is a new Intense Resonance Neutron source (IREN) being under construction. It consists of the electron linear accelerator LUE-200 and the neutron fission core. For the experimental test of the project parameters and the accelerator main systems, the Full Scale Test Facility (FSTF) is being created now in the FLNP, JINR. The FSTF is based on one klystron 5045 (SLAC), the power multiplication system, the RF feeder and one accelerating section. The new klystron modulator M350, based on the OLIVIN station, will be tested on the FSTF as well. The construction of the FSTF is finished now and its electric power equipment, the high voltage power supply system, the 1st variant of the klystron pulsed power supply system, the water-cooling system, the control, blocking and diagnostic system were tested in the nominal regime. Different kinds of capacitors for the modulator forming lines and load equivalents were tested. Elements for the modulator were chosen. The FSTF vacuum and RF systems were projected. (author)

  1. Can Accelerators Accelerate Learning?

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

  2. Use of the TACL [Thaumaturgic Automated Control Logic] system at CEBAF [Continuous Electron Beam Accelerator Facility] for control of the Cryogenic Test Facility

    A logic-based control software system, called Thaumaturgic Automated Control Logic (TACL), is under development at the Continuous Electron Beam Accelerator Facility in Newport News, VA. The first version of the software was placed in service in November, 1987 for control of cryogenics during the first superconducting RF cavity tests at CEBAF. In August, 1988 the control system was installed at the Cryogenic Test Facility (CTF) at CEBAF. CTF generated liquid helium in September, 1988 and is now in full operation for the current round of cavity tests. TACL is providing a powerful and flexible controls environment for the operation of CTF. 3 refs

  3. Plasma accelerators

    Recently attention has focused on charged particle acceleration in a plasma by a fast, large amplitude, longitudinal electron plasma wave. The plasma beat wave and plasma wakefield accelerators are two efficient ways of producing ultra-high accelerating gradients. Starting with the plasma beat wave accelerator (PBWA) and laser wakefield accelerator (LWFA) schemes and the plasma wakefield accelerator (PWFA) steady progress has been made in theory, simulations and experiments. Computations are presented for the study of LWFA. (author)

  4. Linear Accelerators

    Vretenar, M

    2014-01-01

    The main features of radio-frequency linear accelerators are introduced, reviewing the different types of accelerating structures and presenting the main characteristics aspects of linac beam dynamics.

  5. Stability of CIGS Solar Cells and Component Materials Evaluated by a Step-Stress Accelerated Degradation Test Method: Preprint

    Pern, F. J.; Noufi, R.

    2012-10-01

    A step-stress accelerated degradation testing (SSADT) method was employed for the first time to evaluate the stability of CuInGaSe2 (CIGS) solar cells and device component materials in four Al-framed test structures encapsulated with an edge sealant and three kinds of backsheet or moisture barrier film for moisture ingress control. The SSADT exposure used a 15oC and then a 15% relative humidity (RH) increment step, beginning from 40oC/40%RH (T/RH = 40/40) to 85oC/70%RH (85/70) as of the moment. The voluminous data acquired and processed as of total DH = 3956 h with 85/70 = 704 h produced the following results. The best CIGS solar cells in sample Set-1 with a moisture-permeable TPT backsheet showed essentially identical I-V degradation trend regardless of the Al-doped ZnO (AZO) layer thickness ranging from standard 0.12 μm to 0.50 μm on the cells. No clear 'stepwise' feature in the I-V parameter degradation curves corresponding to the SSADT T/RH/time profile was observed. Irregularity in I-V performance degradation pattern was observed with some cells showing early degradation at low T/RH < 55/55 and some showing large Voc, FF, and efficiency degradation due to increased series Rs (ohm-cm2) at T/RH ≥ 70/70. Results of (electrochemical) impedance spectroscopy (ECIS) analysis indicate degradation of the CIGS solar cells corresponded to increased series resistance Rs (ohm) and degraded parallel (minority carrier diffusion/recombination) resistance Rp, capacitance C, overall time constant Rp*C, and 'capacitor quality' factor (CPE-P), which were related to the cells? p-n junction properties. Heating at 85/70 appeared to benefit the CIGS solar cells as indicated by the largely recovered CPE-P factor. Device component materials, Mo on soda lime glass (Mo/SLG), bilayer ZnO (BZO), AlNi grid contact, and CdS/CIGS/Mo/SLG in test structures with TPT showed notable to significant degradation at T/RH ≥ 70/70. At T/RH = 85/70, substantial blistering of

  6. New methods for optical distance indicator and gantry angle quality control tests in medical linear accelerators: image processing by using a 3D phantom

    Shandiz, Mahdi Heravian; Khalilzadeh, Mohammadmahdi; Anvari, Kazem [Mashhad Branch, Islamic Azad University, Mashhad (Iran, Islamic Republic of); Layen, Ghorban Safaeian [Mashhad University of Medical Science, Mashhad (Iran, Islamic Republic of)

    2015-03-15

    In order to keep the acceptable level of the radiation oncology linear accelerators, it is necessary to apply a reliable quality assurance (QA) program. The QA protocols, published by authoritative organizations, such as the American Association of Physicists in Medicine (AAPM), determine the quality control (QC) tests which should be performed on the medical linear accelerators and the threshold levels for each test. The purpose of this study is to increase the accuracy and precision of the selected QC tests in order to increase the quality of treatment and also increase the speed of the tests to convince the crowded centers to start a reliable QA program. A new method has been developed for two of the QC tests; optical distance indicator (ODI) QC test as a daily test and gantry angle QC test as a monthly test. This method uses an image processing approach utilizing the snapshots taken by the CCD camera to measure the source to surface distance (SSD) and gantry angle. The new method of ODI QC test has an accuracy of 99.95% with a standard deviation of 0.061 cm and the new method for gantry angle QC has a precision of 0.43 degrees. The automated proposed method which is used for both ODI and gantry angle QC tests, contains highly accurate and precise results which are objective and the human-caused errors have no effect on the results. The results show that they are in the acceptable range for both of the QC tests, according to AAPM task group 142.

  7. New methods for optical distance indicator and gantry angle quality control tests in medical linear accelerators: image processing by using a 3D phantom

    In order to keep the acceptable level of the radiation oncology linear accelerators, it is necessary to apply a reliable quality assurance (QA) program. The QA protocols, published by authoritative organizations, such as the American Association of Physicists in Medicine (AAPM), determine the quality control (QC) tests which should be performed on the medical linear accelerators and the threshold levels for each test. The purpose of this study is to increase the accuracy and precision of the selected QC tests in order to increase the quality of treatment and also increase the speed of the tests to convince the crowded centers to start a reliable QA program. A new method has been developed for two of the QC tests; optical distance indicator (ODI) QC test as a daily test and gantry angle QC test as a monthly test. This method uses an image processing approach utilizing the snapshots taken by the CCD camera to measure the source to surface distance (SSD) and gantry angle. The new method of ODI QC test has an accuracy of 99.95% with a standard deviation of 0.061 cm and the new method for gantry angle QC has a precision of 0.43 degrees. The automated proposed method which is used for both ODI and gantry angle QC tests, contains highly accurate and precise results which are objective and the human-caused errors have no effect on the results. The results show that they are in the acceptable range for both of the QC tests, according to AAPM task group 142.

  8. Impedance Measurements of Polyester-Coated Galvanised Mild Steel in 10xAcid Rainwater After an Accelerated Wet-Dry Test

    DEHRİ, İlyas

    2000-01-01

    The variation of defective polyester-coated performance with time in 10xacid rain solution was investigated using electrochemical impedance spectroscopy. Measurements were carried out on samples after an accelerated atmospheric corrosion test. The impedance diagrams (Nyquist plots) were simulated using the EQUIVCRT program which was elaborated by Boukamp and the semi-ellipse model which was developed by Erbil. It has been shown that the defective coating resistance changes with time for the s...

  9. Field calculations, single-particle tracking, and beam dynamics with space charge in the electron lens for the Fermilab Integrable Optics Test Accelerator

    Noll, Daniel; Stancari, Giulio

    2015-01-01

    An electron lens is planned for the Fermilab Integrable Optics Test Accelerator as a nonlinear element for integrable dynamics, as an electron cooler, and as an electron trap to study space-charge compensation in rings. We present the main design principles and constraints for nonlinear integrable optics. A magnetic configuration of the solenoids and of the toroidal section is laid out. Single-particle tracking is used to optimize the electron path. Electron beam dynamics at high intensity is...

  10. Simulations Of The Acceleration In Two-Beam Test Stand In CTF3 And Comparison With The Measurements

    Kononenko, Oleksiy

    2011-01-01

    The simulations of the beam acceleration in the presence of the structure's detuning are performed and a good agreement with the experimental results is demonstrated. This study helped the CTF3 team to understand better the system and confirm their beliefs.

  11. Accelerated Testing and Modeling of Potential-Induced Degradation as a Function of Temperature and Relative Humidity

    Hacke, Peter; Spataru, Sergiu; Terwilliger, Kent;

    2015-01-01

    An acceleration model based on the Peck equation was applied to power performance of crystalline silicon cell modules as a function of time and of temperature and humidity, which are the two main environmental stress factors that promote potential-induced degradation (PID). This model was derived...

  12. Accelerated Testing and Modeling of Potential-Induced Degradation as a Function of Temperature and Relative Humidity

    Hacke, Peter; Spataru, Sergiu; Terwilliger, Kent;

    2015-01-01

    An acceleration model based on the Peck equation was applied to power performance of crystalline silicon cell modules as a function of time and of temperature and humidity, the two main environmental stress factors that promote potential-induced degradation. This model was derived from module pow...

  13. Angular velocities, angular accelerations, and coriolis accelerations

    Graybiel, A.

    1975-01-01

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

  14. Study and implementation of a thermal acceleration test for the improvement of the quality and reliability of components and systems; Estudo e implementacao de um teste de aceleracao termica para a melhoria da qualidade e confiabilidade de componentes e sistemas

    Leao, Felippe Carneiro

    1993-09-01

    The objective of this work is to introduce the application of the burn-in test (test of thermal acceleration) in electronic products, using the practical example of this test in a power supply and to do an analysis of the application of this test in a production line showing the advantages and disadvantages of its implementation. For that it is made an abbreviation presentation of the basic concepts of quality and reliability. Starting from these concepts are presented the statistical models used in reliability, that describe the behavior of life of products and components. Besides showing, from the speed chemical reaction model , the influence of the temperature about this reliability.

  15. A note on the falsification of the general theory of relativity by means of an acceleration test

    It is a well recognised fact that the results of the Fitzgerald-Lorentz-Larmor ether theory cannot be experimentally distinguished from the results obtained in the framework of the special theory of relativity. The difference between these two theories can be realised only on the basis of an epistemological analysis. A quite different situation appears when considering the general theory of relativity. Einstein's theory is based on the supposition that the Minkowski geometry is the right geometry for the description of the physical world. The validity of the Minkowski geometry, however, is bounded on the important (tacit) supposition that the rates of the used clocks are not affected by their acceleration. Therefore, an experiment which would show that the proper time of a particle depends on its acceleration would falsify the very basis of Einstein's theory of gravitation. (Auth.)

  16. Construction and Test of a 10 Kv Ion Accelerator in the Faculty of Science of U.N.A.M

    Fuentes, B. E.; Yousif, F. B.; López-Patiaño, J.

    A low energy accelerator was constructed in the Faculty of Science of the National Autonomous University of Mexico (UNAM) for atomic and molecular experiments in the energy range 1.0 - 10.0 keV. We present a general description as well as results of experiments performed by undergraduate and graduate physics students in different stages of the construction. Experiments include characterization of the velocity filter, identification of hydrogen ions and TOF spectra.

  17. Correlations of Capacitance-Voltage Hysteresis with Thin-Film CdTe Solar Cell Performance During Accelerated Lifetime Testing

    Albin, D.; del Cueto, J.

    2011-03-01

    In this paper we present the correlation of CdTe solar cell performance with capacitance-voltage hysteresis, defined presently as the difference in capacitance measured at zero-volt bias when collecting such data with different pre-measurement bias conditions. These correlations were obtained on CdTe cells stressed under conditions of 1-sun illumination, open-circuit bias, and an acceleration temperature of approximately 100 degrees C.

  18. Superconducting accelerator magnets

    In the near future, a large number of high quality superconducting dipole and quadrupole magnets will be required for construction of the next generation multi-TeV high energy hadron accelerator-colliders. To establish the construction technology of such accelerator- colliders, extensive and world-wide R and D programs are now carrying out at several laboratories. In this paper the important issues in superconducting accelerator magnets such as cables, design, fabrication, testing and cryogenic system are discussed together with some details on coil cross- sectional current configurations, quality control of materials, quench protections, radiation heating and etc. The key technology in superconducting accelerator magnets is summarized

  19. High-intensity accelerators

    The design of high-intensity accelerators is described, using examples of machines being built at the Los Alamos National Laboratory. The major design problem with these accelerators is associated with control of beam loss when accelerator intensity is increased. Beam dynamics, beam loss, and the radio-frequency quadrupole structure are discussed in the first part of the chapter followed by an explanation of plans to achieve high-intensity operation in three projects: the Fusion Material Irradiation Tests (a joint effort with the Hanford Development Laboratory in Richland, Washington), the Proton Storage Ring (an addition to the LAMPF accelerator), and the Racetrack Microtron Project

  20. Environmental aging in polycrystalline-Si photovoltaic modules: comparison of chamber-based accelerated degradation studies with field-test data

    Lai, T.; Biggie, R.; Brooks, A.; Potter, B. G.; Simmons-Potter, K.

    2015-09-01

    Lifecycle degradation testing of photovoltaic (PV) modules in accelerated-degradation chambers can enable the prediction both of PV performance lifetimes and of return-on-investment for installations of PV systems. With degradation results strongly dependent on chamber test parameters, the validity of such studies relative to fielded, installed PV systems must be determined. In the present work, accelerated aging of a 250 W polycrystalline silicon module is compared to real-time performance degradation in a similar polycrystalline-silicon, fielded, PV technology that has been operating since October 2013. Investigation of environmental aging effects are performed in a full-scale, industrial-standard environmental chamber equipped with single-sun irradiance capability providing illumination uniformity of 98% over a 2 x 1.6 m area. Time-dependent, photovoltaic performance (J-V) is evaluated over a recurring, compressed night-day cycle providing representative local daily solar insolation for the southwestern United States, followed by dark (night) cycling. This cycle is synchronized with thermal and humidity environmental variations that are designed to mimic, as closely as possible, test-yard conditions specific to a 12 month weather profile for a fielded system in Tucson, AZ. Results confirm the impact of environmental conditions on the module long-term performance. While the effects of temperature de-rating can be clearly seen in the data, removal of these effects enables the clear interpretation of module efficiency degradation with time and environmental exposure. With the temperature-dependent effect removed, the normalized efficiency is computed and compared to performance results from another panel of similar technology that has previously experienced identical climate changes in the test yard. Analysis of relative PV module efficiency degradation for the chamber-tested system shows good comparison to the field-tested system with ~2.5% degradation following

  1. High Gradient Accelerator Research

    Temkin, Richard [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Dept. of Physics. Plasma Science and Fusion Center

    2016-07-12

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

  2. Switched Matrix Accelerator

    We describe a new concept for a microwave circuit functioning as a charged-particle accelerator at mm-wavelengths, permitting an accelerating gradient higher than conventional passive circuits can withstand consistent with cyclic fatigue. The device provides acceleration for multiple bunches in parallel channels, and permits a short exposure time for the conducting surface of the accelerating cavities. Our analysis includes scalings based on a smooth transmission line model and a complementary treatment with a coupled-cavity simulation. We provide also an electromagnetic design for the accelerating structure, arriving at rough dimensions for a seven-cell accelerator matched to standard waveguide and suitable for bench tests at low power in air at 91.392. GHz. A critical element in the concept is a fast mm-wave switch suitable for operation at high-power, and we present the considerations for implementation in an H-plane tee. We discuss the use of diamond as the photoconductor switch medium

  3. Teste de frio e envelhecimento acelerado na avaliação de vigor de sementes de feijão-frade Evaluation of the cowpea seeds vigour through of the coldtest and accelerated aging test

    Josiane Marlle Guiscem

    2010-12-01

    Full Text Available Este trabalho teve como objetivo avaliar o vigor de sementes de feijão-caupi ou feijão-frade por meio dos testes de frio e de envelhecimento acelerado. Utilizou-se as seguintes cultivares de feijão-frade: BRS Guariba, BR 17 Gurguéia, BRS Marataoã, Quarentão e Vinagre. O experimento foi conduzido na Universidade Estadual do Maranhão onde se utilizou para o teste de envelhecimento acelerado as temperaturas e tempo de exposição: 41ºC, 42ºC 43ºC e 45ºC durante 48 h e 42ºC durante 72 h e para o teste de frio: 10ºC, 13ºC e 15ºC com 3, 4 e 5 dias de exposição. Os resultados revelaram que o teste de envelhecimento acelerado com 43ºC/48 h e para o de frio 10º /3 dias foram os mais adequados e que os testes de envelhecimento 42ºC /48 h e de frio 10ºC/3dias se correlacionaram entre si coeficiente de correlação de 0,97%. Pelos resultados conclui-se que os testes estudados apresentaram sensibilidade para identificar diferenças no vigor de sementes de feijão-frade.Aiming to evaluate the efficiency of different methods of accelerated aging and cold test to determine the physiological quality of seed of five cultivars of cowpea: BRS Guariba, BR 17 Gurguéia, BRS Marataoã, Quarentão e Vinagre. The experiment was conducted at the laboratory of University State of Maranhão - UEMA. In the accelera-ted aging test were used the following temperature and time of exposure: 41ºC, 42°C , 43°C and 45°C for 48 hours and 42 ° C for 72 hours. In cold test were used 10ºC, 13°C and 15ºC for 3, 4 and 5 days of exposure. Tests showed that the accelerated aging test of the combination of 43ºC/48 hours and for cold test the combination 15ºC/ 5 days were the most appropriate for the evaluation of the potential of physiological cultivars of cowpea seed. The accelerated aging tests 42°C/48 hours and of cold test 15ºC/3 days were those that had greater consistency in the separation of lots of cultivars of seed cowpea because of correlation

  4. Future accelerators (?)

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

  5. Future accelerators (?)

    John Womersley

    2003-08-21

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

  6. Accelerating Value Creation with Accelerators

    Jonsson, Eythor Ivar

    2015-01-01

    accelerator programs. Microsoft runs accelerators in seven different countries. Accelerators have grown out of the infancy stage and are now an accepted approach to develop new ventures based on cutting-edge technology like the internet of things, mobile technology, big data and virtual reality. It is also......Accelerators can help to accelerate value creation. Accelerators are short-term programs that have the objective of creating innovative and fast growing ventures. They have gained attraction as larger corporations like Microsoft, Barclays bank and Nordea bank have initiated and sponsored...

  7. Field calculations, single-particle tracking, and beam dynamics with space charge in the electron lens for the Fermilab Integrable Optics Test Accelerator

    Noll, Daniel [Goethe Univ., Frankfurt (Germany); Stancari, Giulio [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2015-11-17

    An electron lens is planned for the Fermilab Integrable Optics Test Accelerator as a nonlinear element for integrable dynamics, as an electron cooler, and as an electron trap to study space-charge compensation in rings. We present the main design principles and constraints for nonlinear integrable optics. A magnetic configuration of the solenoids and of the toroidal section is laid out. Singleparticle tracking is used to optimize the electron path. Electron beam dynamics at high intensity is calculated with a particle-in-cell code to estimate current limits, profile distortions, and the effects on the circulating beam. In the conclusions, we summarize the main findings and list directions for further work.

  8. Reliability of n-CdS/p-CdTe solar modules in accelerated environmental tests and effect of oxygen

    Nakano, A. (Matsushita Battery Industrial Co. Ltd., Moriguchi, Osaka (Japan). Solar Battery Div.)

    1990-10-01

    The reliability under various severe environmental conditions was investigated in n-CdS/p-CdTe solar modules that contained air and an oxygen-releasing agent inside a sealed space between the glass substrate and the back sheet of the module. The modules were stable in an 80deg C test, an 80deg C-90% relative humidity-test, a 10-cycle heat shock test and a temperature-and-humidity cycle test but were unstable in a weather meter (dew cycle) test. A kneed point was observed in the degradation curve when relative output power was plotted against test period for the weather meter test. It was thought that the modules became unstable when the concentration of oxygen in the sealed space exceeded 2 vol.%. (orig.).

  9. Accelerated tests of hardened cement pastes alteration by organic acids: analysis of the pH effect

    Effluents, such as liquid manure and silage effluents, stored in silos often made of concrete, contain organic acids that are chemically very aggressive for the cement-based matrix. The pH of liquid manure is comprised between 6 and 8, and the pH of silage effluent is about 4. There has already been much research done on manure's effect on concrete using aggressive solutions with a pH of or inferior to 4, in order to accelerate alteration kinetics. These studies aimed at simulating liquid manure and silage effluent, equally. The goal of this article is to validate the use of solutions with a pH of 4 to implement accelerated studies on alterations occurring to structures exposed to the acidic part of liquid manure. In this study, the alteration mechanisms of the cement-based matrix produced by two solutions of organic acids with pH of 4 and 6 were compared. At the end of the experiment, carried out on ordinary Portland cement and slag cement pastes, the kinetics of alteration of the cement pastes immersed in the solution with a pH of 4 was ninefold higher than in the solution with a pH of 6. The chemical and mineralogical modifications of the paste were analyzed by electron microprobe, XRD and BSE mode observations. It was shown that the alteration mechanisms of the paste are sensibly identical for both solutions: almost complete decalcification, the disappearance of the crystallized or amorphous hydrated phases and the probable formation of a silica gel containing aluminum and iron, mainly. The differences in alteration mechanisms between the two solutions are minor and mainly concern the stability of the anhydrous phases: C4AF and slag grains

  10. VERIFICATION OF THE EFFECT OF CONCRETE SURFACE PROTECTION ON THE PERMEABILITY OF ACID GASES USING ACCELERATED CARBONATION DEPTH TEST IN AN ATMOSPHERE OF 98% CO2

    JIŘÍ NOVÁK

    2011-03-01

    Full Text Available Carbonation is one of the corrosion processes negatively influencing the properties of mature concrete. It is caused by a chemical reaction between carbon dioxide infiltrating the surface of a concrete structure and the minerals of the mastic cement. The surface of a concrete structure can be protected from the effects of atmospheric CO2 by coating with modern waterborne epoxy dispersions. Out of the four types of dispersions tested (dispersion A – CHS Epoxy 200 V 55 + hardener Telalit 180, 2 layers; dispersion B – DOW XZ 92 533 + hardener XZ 92 441.01, 2 layers; dispersion C – CHS Epoxy 200 V 55 + hardener Telalit 180, 1st layer + Epostyl 217 V, 2nd layer; dispersion D – Epostyl 217 V, 2 layers, the type A solvent-based epoxy dispersion and the type C combination of the solvent-based and the solvent-free emulsions demonstrated the highest degree of protection of cement mortar. The effect and actual protection time was evaluated by means of the „accelerated carbonation depth test in 98% CO2“.The correlation dependence found in the so-called ”accelerated test“ enables us to determine intervals of real time in the natural environment of 0.03% CO2 corresponding to the intervals of accelerated exposition in 98% CO2. It may be said that in the case of type A, type B, type C and type D coatings on higher-quality concretes, the coating would have to be renewed with an interval of maximum eight years.

  11. Accelerated aging tests on ENEA-ASE solar coating for receiver tube suitable to operate up to 550 °C

    Antonaia, A.; D'Angelo, A.; Esposito, S.; Addonizio, M. L.; Castaldo, A.; Ferrara, M.; Guglielmo, A.; Maccari, A.

    2016-05-01

    A patented solar coating for evacuated receiver, based on innovative graded WN-AlN cermet layer, has been optically designed and optimized to operate at high temperature with high performance and high thermal stability. This solar coating, being designed to operate in solar field with molten salt as heat transfer fluid, has to be thermally stable up to the maximum temperature of 550 °C. With the aim of determining degradation behaviour and lifetime prediction of the solar coating, we chose to monitor the variation of the solar absorptance αs after each thermal annealing cycle carried out at accelerated temperatures under vacuum. This prediction method was coupled with a preliminary Differential Thermal Analysis (DTA) in order to give evidence for any chemical-physical coating modification in the temperature range of interest before performing accelerated aging tests. In the accelerated aging tests we assumed that the temperature dependence of the degradation processes could be described by Arrhenius behaviour and we hypothesized that a linear correlation occurs between optical parameter variation rate (specifically, Δαs/Δt) and degradation process rate. Starting from Δαs/Δt values evaluated at 650 and 690 °C, Arrhenius plot gave an activation energy of 325 kJ mol-1 for the degradation phenomenon, where the prediction on the coating degradation gave a solar absorptance decrease of only 1.65 % after 25 years at 550 °C. This very low αs decrease gave evidence for an excellent stability of our solar coating, also when employed at the maximum temperature (550 °C) of a solar field operating with molten salt as heat transfer fluid.

  12. Influence of Lentinus edodes and Agaricus blazei extracts on the prevention of oxidation and retention of tocopherols in soybean oil in an accelerated storage test.

    da Silva, Ana Carolina; Jorge, Neuza

    2014-06-01

    This study aimed to evaluate the influence of the methanol extracts of mushrooms Lentinus edodes and Agaricus blazei on the retention of tocopherols in soybean oil, when subjected to an accelerated storage test. The following treatments were subjected to an accelerated storage test in an oven at 60 °C for 15 days: Control (soybean oil without antioxidants), TBHQ (soybean oil + 100 mg/kg of TBHQ), BHT (soybean oil + 100 mg/kg of BHT), L. edodes (soybean oil + 3,500 mg/kg of L. edodes extract) and A. blazei (soybean oil + 3,500 mg/kg of A. blazei extract). The samples were analyzed for tocopherols naturally present in soybean oil and mass gain. The results showed, the time required to reach a 0.5% increase in mass was 13 days for TBHQ and 15 days for A. blazei. The content of tocopherols for TBHQ was 457.50 mg/kg and the A. blazei, 477.20 mg/kg. PMID:24876658

  13. Recent US target-physics-related research in heavy-ion inertial fusion: simulations for tamped targets and for disk experiments in accelerator test facilities

    Calculations suggest that experiments relating to disk heating, as well as beam deposition, focusing and transport can be performed within the context of current design proposals for accelerator test-facilities. Since the test-facilities have lower ion kinetic energy and beam pulse power as compared to reactor drivers, we achieve high-beam intensities at the focal spot by using short focal distance and properly designed beam optics. In this regard, the low beam emittance of suggested multi-beam designs are very useful. Possibly even higher focal spot brightness could be obtained by plasma lenses which involve external fields on the beam which is stripped to a higher charge state by passing through a plasma cell. Preliminary results suggest that intensities approx. 1013 - 1014 W/cm2 are achievable. Given these intensities, deposition experiments with heating of disks to greater than a million degrees Kelvin (100 eV) are expected

  14. Design, Fabrication and High Power RF Test of a C-band Accelerating Structure for Feasibility Study of the SPARC photo-injector energy upgrade

    Alesini, D.; Di Pirro, G.; Di Raddo, R.; Ferrario, M.; Gallo, A.; Lollo, V.; Marcellini, F.; Higo, T.; Kakihara, K.; Matsumoto, S.; Campogiani, G.; Mostacci, A.; Palumbo, L.; Persichelli, S.; Spizzo, V.; Verdú-Andrés, S.

    2011-01-01

    The energy upgrade of the SPARC photo-injector from 160 to more than 260 MeV will be done by replacing a low gradient 3m S-Band structure with two 1.4m high gradient C-band structures. The structures are travelling wave, constant impedance sections, have symmetric waveguide input couplers and have been optimized to work with a SLED RF input pulse. A prototype with a reduced number of cells has been fabricated and tested at high power in KEK (Japan) giving very good performances in terms of breakdown rates (10^6 bpp/m) at high accelerating gradient (>50 MV/m). The paper illustrates the design criteria of the structures, the fabrication procedure and the high power RF test results.

  15. Thick target benchmark test for the code used in the design of high intensity proton accelerator project

    In the neutronics design for the JAERI and KEK Joint high intensity accelerator facilities, transport codes of NMTC/JAM, MCNPX and MARS are used. In order to confirm the predict ability for these code, it is important to compare with the experiment result. For the validation of the source term of neutron, the calculations are compared with the experimental spectrum of neutrons produced from thick target, which are carried out at LANL and KEK. As for validation of low energy incident case, the calculations are compared with experiment carried out at LANL, in which target of C, Al, Fe, and 238U are irradiated with 256-MeV protons. By the comparison, it is found that both NMTC/JAM and MCNPX show good agreement with the experiment within by a factor of 2. MARS shows good agreement for C and Al target. MARS, however, gives rather underestimation for all targets in the neutron energy region higher than 30 MeV. For the validation high incident energy case, the codes are compared with the experiment carried out at KEK. In this experiment, W and Pb targets are bombarded with 0.5- and 1.5-GeV protons. Although slightly disagreement exists, NMTC/JAM, MCNPX and MARS are in good agreement with the experiment within by a factor of 2. (author)

  16. Step-stress Accelerated Degradation Testing for Solar Reflectors%美国太阳反射镜步进应力加速老化试验

    李迪凡; 张凯; 张燕; 符朝旭; 朱玉琴

    2014-01-01

    To meet the challenge of reducing the cost of electricity generated with concentrating solar power (CSP), new low-cost reflector materials are being developed, including metalized polymer reflectors. By being exposed solar reflec-tors to UV-light, we used the application of testing methods and statistical inference techniques to quantitative evaluate and improve service lifetime of solar reflectors associated with failure mechanisms, which are exposed to UV-light. We will take advantage of the Ultra Accelerated Weathering System (UAWS) to assess various degradation patterns caused by acceler-ated aging because of exposing to UV. On account of numbers of samples, test conditions, performance degradation, failure patterns and other reasons, the test results may be used to further deduce failure mechanisms, associated physical parame-ters, service lifetimes, and uncertainties. In necessary and complicated circumstances, we can use advanced planning and statistical inference, and propose step-stress accelerated degradation testing (SSADT) methods.%为了应对降低聚光发电(CSP)成本带来的挑战,研发新型的低成本反射镜材料,包括金属聚合物反射镜。通过将太阳反射镜暴露在紫外光下,利用试验应用方法和统计推论技术,定量评估和改进太阳光反射镜在紫外光下与失效机制相关的使用寿命。将利用超加速环境系统评估由紫外暴露加速老化导致的多种性能退化模式。由于样品数量、试验条件、性能退化和失效模式等原因,试验结果可用于深入推导失效机制、关联物理参数、服役寿命和不确定性。在有必要利用高级方案和统计推论的复杂情况下,建议采用步进应力加速老化试验方法。

  17. Standard test method for accelerated leach test for diffusive releases from solidified waste and a computer program to model diffusive, fractional leaching from cylindrical waste forms

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This test method provides procedures for measuring the leach rates of elements from a solidified matrix material, determining if the releases are controlled by mass diffusion, computing values of diffusion constants based on models, and verifying projected long-term diffusive releases. This test method is applicable to any material that does not degrade or deform during the test. 1.1.1 If mass diffusion is the dominant step in the leaching mechanism, then the results of this test can be used to calculate diffusion coefficients using mathematical diffusion models. A computer program developed for that purpose is available as a companion to this test method (Note 1). 1.1.2 It should be verified that leaching is controlled by diffusion by a means other than analysis of the leach test solution data. Analysis of concentration profiles of species of interest near the surface of the solid waste form after the test is recommended for this purpose. 1.1.3 Potential effects of partitioning on the test results can...

  18. Laser accelerator

    Vigil, Ricardo

    2014-01-01

    Approved for public release; distribution is unlimited In 1979,W. B. Colson and S. K. Ride proposed a new kind of electron accelerator using a uniform magnetic field in combination with a circularly-polarized laser field. A key concept is to couple the oscillating electric field to the electron’s motion so that acceleration is sustained. This dissertation investigates the performance of the proposed laser accelerator using modern high powered lasers and mag-netic fields that are significan...

  19. Design of an accelerated test to determine the attack of the sulphates on concrete structures, and the suggest alternative to design a container

    This work at demonstrating one of the accelerated tests in the frame of the Norm ASTM E-632-82, in order to evaluate the life of service for Reinforced Concrete Structures with High Performance.These will be used as barriers of engineering in containers for Radioactive Wastes.The results of the evaluation are necessary for the probabilistic and deterministic analysis, which are required to obtain licentiate for the emplacement and construction of this type of installations.Since concrete is the principal material used in this type of containers, its properties, in particular, its durability must be evaluated taking into accounts both, intrinsic factors and the extrinsic factors.Within the intrinsic factors we can mention your formulation, including design of armors of steel, production, treated and structural design.As extrinsic factors, weather and environmental, soil characteristic and service operation must be considered.It is important to emphasize that within the criteria used in the conceptual design of these types of repositories, the structures that act of barrier must not alter their insulation properties during all the period of service, which may be several hundreds of years.Although it is not possible to guarantee that repository's performance will not be altered throughout its time of service, the fact to obtain results of accelerated tests and the long term, it will enable us to estimate the durability of such structures, across the support of mathematical suitable models.The different stages which should be taken into account for the development of the evaluation tests, determining the relevant parameters to be considered in them and results obtained so far, are showing in this work

  20. Loading frequencies up to 20Hz as an alternative to accelerate fatigue strength tests in a Y-TZP ceramic.

    Fraga, Sara; Pereira, Gabriel Kalil Rocha; Freitas, Mariana; Kleverlaan, Cornelis Johannes; Valandro, Luiz Felipe; May, Liliana Gressler

    2016-08-01

    Considering the interest of the research community in the fatigue behavior of all-ceramic restorations and the time consumed in low-frequency cyclic fatigue tests, this study aimed to investigate the influence of the loading frequency on the zirconia fatigue strength. The biaxial flexural fatigue strength of Y-TZP discs was determined by the staircase approach after 500,000 cycles. The investigated frequencies were 2Hz (control-simulation of the chewing activity; n=20), 10Hz (n=20), 20Hz (n=20), and 40Hz (n=21). The fatigue strength data were analyzed using one-way ANOVA and post-hoc Tukey׳s test (α=0.05). Pearson coefficient (r) was calculated to assess the existence of a correlation between fatigue strength and loading frequency. X-ray diffraction analysis was used to determine the relative amount of monoclinic phase under each fatigue test condition. The fatigue strength was significantly higher for 40Hz group (630.7±62.1MPa) and did not differ among the groups 2Hz (550.3±89.7MPa), 10Hz (574.0±47MPa) and 20Hz (605.1±30.7MPa). Pearson correlation coefficient indicated a significantly moderate correlation (r=0.57) between fatigue strength and loading frequency. The percentage of monoclinic phase was similar among the groups. Therefore, the use of loading frequencies up to 20Hz seems a good alternative to expedite the cycling strength fatigue tests in polycrystalline ceramics without significantly changing the fatigue behavior showed by zirconia in tests employing the frequency of the masticatory cycle. PMID:26849030

  1. Test input of radio-frequency power into the resonator mockup to the second part of the linear accelerator of a meson factory

    On the experimental stand of the Radio Engineering Institute of the Academy of Sciences of the USSR the accelerating structures for the second portion of the ''meson factory'' are researched. The test power input into the models of of the accelerating structures is accomplished from a powerful pulse klystron generator with external excitation and operating frequency of 991 MHz. The pulse duration of 140 μ s can be diminished as required during ageing of the resonator. The power is adjusted within wide limits. The wave-guide feeders measuring 220 104 terminate in the can-type sealing ports incorporating fused quartz discs and matching diaphragms. The standing wave coefficient in the feeder does not exceed 1.4. The temperature of the cooling water at the resonator input is kept stable. Under nominal conditions the average intensity of the electric field on the axis is 36 kV/cm, the pulse power of the r-f losses in the resonator is equal to 0.9 MW, the average power amounts to 11 kW

  2. FMIT accelerator vacuum system

    The Fusion Materials Irradiation Test (FMIT) Facility accelerator is being designed to continuously accelerate 100-mA deuterons to 25 MeV. High vacuum pumping of the accelerator structure and beam lines will be done by ion pumps and titanium sublimation pumps. The design of the roughing system includes a Roots blower/mechanical pump package. For economy the size of the system has been designed to operate at 10-6 torr, where beam particle scattering on residual gases is negligible. For minimum maintenance in this neutron factory, the FMIT vacuum system is designed from the point of view of simplicity and reliability

  3. Present status and first results of the final focus beam line at the KEK Accelerator Test Facility

    Bambade, P; Amann, J; Angal-Kalinin, D; Apsimon, R; Araki, S; Aryshev, A; Bai, S; Bellomo, P; Bett, D; Blair, G; Bolzon, B; Boogert, S; Boorman, G; Burrows, P N; Christian, G; Coe, P; Constance, B; Delahaye, J P; Deacon, L; Elsen, E; Faus-Golfe, A; Fukuda, M; Gao, J; Geffroy, N; Gianfelice-Wendt, E; Guler, H; Hayano, H; Heo, A Y; Honda, Y; Huang, J Y; Hwang, W H; Iwashita, Y; Jeremie, A; Jones, J; Kamiya, Y; Karataev, P; Kim, E S; Kim, H S; Kim, S H; Komamiya, S; Kubo, K; Kume, T; Kuroda, S; Lam, B; Lyapin, A; Masuzawa, M; McCormick, D; Molloy, S; Naito, T; Nakamura, T; Nelson, J; Okamoto, D; Okugi, T; Oroku, M; Park, Y J; Parker, B; Paterson, E; Perry, C; Pivi, M; Raubenheimer, T; Renier, Y; Resta-Lopez, J; Rimbault, C; Ross, M; Sanuki, T; Scarfe, A; Schulte, D; Seryi, A; Spencer, C; Suehara, T; Sugahara, R; Swinson, C; Takahashi, T; Tauchi, T; Terunuma, N; Tomas, R; Urakawa, J; Urner, D; Verderi, M; Wang, M H; Warden, M; Wendt, M; White, G; Wittmer, W; Wolski, A; Woodley, M; Yamaguchi, Y; Yamanaka, T; Yan, Y; Yoda, H; Yokoya, K; Zhou, F; Zimmermann, F

    2010-01-01

    ATF2 is a final-focus test beam line which aims to focus the low emittance beam from the ATF damping ring to a vertical size of about 37 nm and to demonstrate nanometer level beam stability. Several advanced beam diagnostics and feedback tools are used. In December 2008, construction and installation were completed and beam commissioning started, supported by an international team of Asian, European, and U.S. scientists. The present status and first results are described.

  4. Present Status And First Results of the Final Focus Beam Line at the KEK Accelerator Test Facility

    Bambade, P.; /Orsay /KEK, Tsukuba; Alabau Pons, M.; /Valencia U., IFIC; Amann, J.; /SLAC; Angal-Kalinin, D.; /Daresbury; Apsimon, R.; /Oxford U., JAI; Araki, S.; Aryshev, A.; /KEK, Tsukuba; Bai, S.; /Beijing, Inst. High Energy Phys.; Bellomo, P.; /SLAC; Bett, D.; /Oxford U., JAI; Blair, G.; /Royal Holloway, U. of London; Bolzon, B.; /Savoie U.; Boogert, S.; Boorman, G.; /Royal Holloway, U. of London; Burrows, P.N.; Christian, G.; Coe, P.; Constance, B.; /Oxford U., JAI; Delahaye, Jean-Pierre; /CERN; Deacon, L.; /Royal Holloway, U. of London; Elsen, E.; /DESY /Valencia U., IFIC /KEK, Tsukuba /Beijing, Inst. High Energy Phys. /Savoie U. /Fermilab /Ecole Polytechnique /KEK, Tsukuba /Kyungpook Natl. U. /KEK, Tsukuba /Pohang Accelerator Lab. /Kyoto U., Inst. Chem. Res. /Savoie U. /Daresbury /Tokyo U. /Royal Holloway, U. of London /Kyungpook Natl. U. /Pohang Accelerator Lab. /Tokyo U. /KEK, Tsukuba /SLAC /University Coll. London /KEK, Tsukuba /SLAC /Royal Holloway, U. of London /KEK, Tsukuba /Tokyo U. /SLAC /Tohoku U. /KEK, Tsukuba /Tokyo U. /Pohang Accelerator Lab. /Brookhaven /SLAC /Oxford U., JAI /SLAC /Orsay /KEK, Tsukuba /Oxford U., JAI /Orsay /Fermilab /Tohoku U. /Manchester U. /CERN /SLAC /Tokyo U. /KEK, Tsukuba /Oxford U., JAI /Hiroshima U. /KEK, Tsukuba /CERN /KEK, Tsukuba /Oxford U., JAI /Ecole Polytechnique /SLAC /Oxford U., JAI /Fermilab /SLAC /Liverpool U. /SLAC /Tokyo U. /SLAC /Tokyo U. /KEK, Tsukuba /SLAC /CERN

    2011-11-11

    ATF2 is a final-focus test beam line which aims to focus the low emittance beam from the ATF damping ring to a vertical size of about 37 nm and to demonstrate nanometer level beam stability. Several advanced beam diagnostics and feedback tools are used. In December 2008, construction and installation were completed and beam commissioning started, supported by an international team of Asian, European, and U.S. scientists. The present status and first results are described.

  5. Induction accelerators

    Takayama, Ken

    2011-01-01

    A broad class of accelerators rests on the induction principle whereby the accelerating electrical fields are generated by time-varying magnetic fluxes. Particularly suitable for the transport of bright and high-intensity beams of electrons, protons or heavy ions in any geometry (linear or circular) the research and development of induction accelerators is a thriving subfield of accelerator physics. This text is the first comprehensive account of both the fundamentals and the state of the art about the modern conceptual design and implementation of such devices. Accordingly, the first part of the book is devoted to the essential features of and key technologies used for induction accelerators at a level suitable for postgraduate students and newcomers to the field. Subsequent chapters deal with more specialized and advanced topics.

  6. Surface modification of nano-silica on the ligament advanced reinforcement system for accelerated bone formation: primary human osteoblasts testing in vitro and animal testing in vivo

    Li, Mengmeng; Wang, Shiwen; Jiang, Jia; Sun, Jiashu; Li, Yuzhuo; Huang, Deyong; Long, Yun-Ze; Zheng, Wenfu; Chen, Shiyi; Jiang, Xingyu

    2015-04-01

    The Ligament Advanced Reinforcement System (LARS) has been considered as a promising graft for ligament reconstruction. To improve its biocompatibility and effectiveness on new bone formation, we modified the surface of a polyethylene terephthalate (PET) ligament with nanoscale silica using atom transfer radical polymerization (ATRP) and silica polymerization. The modified ligament is tested by both in vitro and in vivo experiments. Human osteoblast testing in vitro exhibits an ~21% higher value in cell viability for silica-modified grafts compared with original grafts. Animal testing in vivo shows that there is new formed bone in the case of a nanoscale silica-coated ligament. These results demonstrate that our approach for nanoscale silica surface modification on LARS could be potentially applied for ligament reconstruction.The Ligament Advanced Reinforcement System (LARS) has been considered as a promising graft for ligament reconstruction. To improve its biocompatibility and effectiveness on new bone formation, we modified the surface of a polyethylene terephthalate (PET) ligament with nanoscale silica using atom transfer radical polymerization (ATRP) and silica polymerization. The modified ligament is tested by both in vitro and in vivo experiments. Human osteoblast testing in vitro exhibits an ~21% higher value in cell viability for silica-modified grafts compared with original grafts. Animal testing in vivo shows that there is new formed bone in the case of a nanoscale silica-coated ligament. These results demonstrate that our approach for nanoscale silica surface modification on LARS could be potentially applied for ligament reconstruction. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr01439e

  7. An experimental study of the air-side particulate fouling in finned-tube heat exchangers of air conditioners through accelerated tests

    The air-side particulate fouling in the heat exchangers of HVAC applications degrades the performance of cooling capacity, pressure drop across a heat exchanger, and indoor air quality. Indoor and outdoor air contaminants foul heat exchangers. The purpose of this study is to investigate the fouling characteristics trough accelerated tests. The fouling characteristics are analyzed as functions of a dust concentration (1.28 and 3.84 g/m3), a face velocity (0.5, 1.0, and 1.5 m/s), and a surface condition. The cooling capacity in the slitted finned-tube heat exchangers at the face velocity of 1 m/s decreases about 2% and the pressure drop increases up to 57%. The rate of build-up of fouling is observed to be 3 times slower for this three-fold reduction of dust concentration whilst still approaching the same asymptotic level

  8. The Conversion and operation of the Cornell electron storage ring as a test accelerator (CESRTA) for damping rings research and development

    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 and 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.

  9. 飞艇蒙皮材料加速老化性能试验研究%Research on Accelerated Aging Test of Airship Envelop Material

    张金奎; 刘涛; 鲁国富

    2014-01-01

    目的:研究某飞艇蒙皮材料加速老化性能,以及不同环境因素对飞艇蒙皮材料老化的影响。方法根据某飞艇的使用环境,对 URETEK-3216LV 和 HD-150两种飞艇蒙皮材料进行了实验室加速老化组合试验。结果得到了不同环境条件下两种飞艇蒙皮材料加速老化后断裂强力退化规律。结论 URETEK-3216LV 材料对高湿环境最为敏感,而 HD-150材料对高温环境最为敏感。 URETEK-3216LV 材料耐候性能比 HD-150材料耐候性强。%Objective To study the aging property of envelop material for a certain type of airship and the effect of dif-ferent environmental factors on the airship envelop material. Methods Based on the operation environment of the airship, laboratory accelerated aging combination test was carried out for the two airship envelop materials URETEK-3216LV and HD-150. Results The deterioration law of breaking force of the two airship envelop materials after accelerated aging in dif-ferent environmental conditions was obtained. Conclusion The test results showed that high-humidity environment had the greatest influence on the ageing performance of URETEK-3216LV, while high-temperature environment had the greatest in-fluence on the ageing performance of HD-150. The weatherability of URETEK-3216LV was better than that of HD-150.

  10. Research on Accelerated Aging Test of Airship Envelop Material%飞艇蒙皮材料加速老化性能试验研究

    张金奎; 刘涛; 鲁国富

    2014-01-01

    Objective To study the aging property of envelop material for a certain type of airship and the effect of dif-ferent environmental factors on the airship envelop material. Methods Based on the operation environment of the airship, laboratory accelerated aging combination test was carried out for the two airship envelop materials URETEK-3216LV and HD-150. Results The deterioration law of breaking force of the two airship envelop materials after accelerated aging in dif-ferent environmental conditions was obtained. Conclusion The test results showed that high-humidity environment had the greatest influence on the ageing performance of URETEK-3216LV, while high-temperature environment had the greatest in-fluence on the ageing performance of HD-150. The weatherability of URETEK-3216LV was better than that of HD-150.%目的:研究某飞艇蒙皮材料加速老化性能,以及不同环境因素对飞艇蒙皮材料老化的影响。方法根据某飞艇的使用环境,对 URETEK-3216LV 和 HD-150两种飞艇蒙皮材料进行了实验室加速老化组合试验。结果得到了不同环境条件下两种飞艇蒙皮材料加速老化后断裂强力退化规律。结论 URETEK-3216LV 材料对高湿环境最为敏感,而 HD-150材料对高温环境最为敏感。 URETEK-3216LV 材料耐候性能比 HD-150材料耐候性强。

  11. Estimate of life performance of cable insulating materials from accelerated radiation damage tests for the CERN LEP project

    The Large Electron Positron storage ring, LEP, is at present under construction at CERN. It is estimated that the cables installed in this machine will be exposed to doses of 105 to 5x105 Gy depending on the beam energy. The materials specified for insulation and sheath of these cables are polyethylene, ethylene-propylene rubber and flame retardant halogen-free polyolefins. Radiation damage tests have been carried out on these materials both at high dose rates of 105 Gy/h and low dose rates of 100 Gy/h. From the results of these tests estimates are made on the life performance of the cables. It is shown that depending on the materials, the specified end point criterion of 100% elongation at 106 Gy can be expected to be reduced to 4 to 20% due to long term radiation aging effects. Taking this into account and under the present assumptions of LEP operation parameters for 10 years, the radiation induced degradation must be expected to be severe to moderate for the higher energy stages of the LEP project

  12. Accelerated relative sea-level rise and rapid coastal erosion: Testing a causal relationship for the Louisiana barrier islands

    List, J.H.; Sallenger, A.H., Jr.; Hansen, M.E.; Jaffe, B.E.

    1997-01-01

    The role of relative sea-level rise as a cause for the rapid erosion of Louisiana's barrier island coast is investigated through a numerical implementation of a modified Bruun rule that accounts for the low percentage of sand-sized sediment in the eroding Louisiana shoreface. Shore-normal profiles from 150 km of coastline west of the Mississippi delta are derived from bathymetric surveys conducted during the 1880s. 1930s and 1980s. An RMS difference criterion is employed to test whether an equilibrium profile form is maintained between survey years. Only about half the studied profiles meet the equilibrium Criterion this represents a significant limitation on the potential applicability of the Bruun rule. The profiles meeting the equilibrium criterion, along with measured rates of relative sea-level rise, are used to hindcast shoreline retreat rates at 37 locations within the study area. Modeled and observed shoreline retreat rates show no significant correlation. Thus in terms of the Bruun approach relative sea-level rise has no power for hindcasting (and presumably forecasting) rates of coastal erosion for the Louisiana barrier islands.

  13. In vacuum diamond sensor scanner for beam halo measurements in the beam line at the KEK Accelerator Test Facility

    Liu, Shan; Cornebise, Patrick; Faus-Golfe, Angeles; Fuster-Martínez, Nuria; Griesmayer, Erich; Guler, Hayg; Kubytskyi, Viacheslav; Sylvia, Christophe; Toshiaki, Tauchi; Terunuma, Nobuhiro; Bambade, Philip

    2015-01-01

    The investigation of beam halo transverse distributions is important for the understanding of beam losses and the control of backgrounds in Future Linear Colliders (FLC). A novel in vacuum diamond sensor (DSv) scanner with four strips has been designed and developed for the investigation of the beam halo transverse distributions and also for the diagnostics of Compton recoil electrons after the interaction point (IP) of ATF2, a low energy (1.3 GeV) prototype of the final focus system for the ILC and CLIC linear collider projects. Using the DSv, a dynamic range of $\\sim10^6$ has been successfully demonstrated and confirmed for the first time by simultaneous beam core ($\\sim10^9$ electrons) and beam halo ($\\sim10^3$ electrons) measurements at ATF2. This report presents the characterization, performance studies and tests of the diamond sensors using an $\\alpha$ source as well as using the electron beams at PHIL, a low energy ($< 10$ MeV) photo-injector at LAL, and at ATF2. First beam halo measurement results ...

  14. Collective ion acceleration

    Progress achieved in the understanding and development of collective ion acceleration is presented. Extensive analytic and computational studies of slow cyclotron wave growth on an electron beam in a helix amplifier were performed. Research included precise determination of linear coupling between beam and helix, suppression of undesired transients and end effects, and two-dimensional simulations of wave growth in physically realizable systems. Electrostatic well depths produced exceed requirements for the Autoresonant Ion Acceleration feasibility experiment. Acceleration of test ions to modest energies in the troughs of such waves was also demonstrated. Smaller efforts were devoted to alternative acceleration mechanisms. Langmuir wave phase velocity in Converging Guide Acceleration was calculated as a function of the ratio of electron beam current to space-charge limiting current. A new collective acceleration approach, in which cyclotron wave phase velocity is varied by modulation of electron beam voltage, is proposed. Acceleration by traveling Virtual Cathode or Localized Pinch was considered, but appears less promising. In support of this research, fundamental investigations of beam propagation in evacuated waveguides, of nonneutral beam linear eigenmodes, and of beam stability were carried out. Several computer programs were developed or enhanced. Plans for future work are discussed

  15. Collective ion acceleration

    Godfrey, B.B.; Faehl, R.J.; Newberger, B.S.; Shanahan, W.R.; Thode, L.E.

    1977-01-01

    Progress achieved in the understanding and development of collective ion acceleration is presented. Extensive analytic and computational studies of slow cyclotron wave growth on an electron beam in a helix amplifier were performed. Research included precise determination of linear coupling between beam and helix, suppression of undesired transients and end effects, and two-dimensional simulations of wave growth in physically realizable systems. Electrostatic well depths produced exceed requirements for the Autoresonant Ion Acceleration feasibility experiment. Acceleration of test ions to modest energies in the troughs of such waves was also demonstrated. Smaller efforts were devoted to alternative acceleration mechanisms. Langmuir wave phase velocity in Converging Guide Acceleration was calculated as a function of the ratio of electron beam current to space-charge limiting current. A new collective acceleration approach, in which cyclotron wave phase velocity is varied by modulation of electron beam voltage, is proposed. Acceleration by traveling Virtual Cathode or Localized Pinch was considered, but appears less promising. In support of this research, fundamental investigations of beam propagation in evacuated waveguides, of nonneutral beam linear eigenmodes, and of beam stability were carried out. Several computer programs were developed or enhanced. Plans for future work are discussed.

  16. Tests of an environmental and personnel safe cleaning process for Brookhaven National Laboratory accelerator and storage ring components

    A large measure of the successful operation of the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory (BNL) for over a decade can be attributed to the cleaning of its ultrahigh vacuum (UHV) components during and after construction. A new UHV cleaning process, which has to be environmentally and personnel safe, is needed to replace the harsh, unfriendly process which is still in use. Dow Advanced Cleaning Systems was contracted to develop a replacement process without the use of harsh chemicals and which must clean vacuum surfaces as well as the existing process. Acceptance of the replacement process was primarily based on photon stimulated desorption (PSD) measurements of beam tube samples run on NSLS beam line U10B. One meter long beam tube samples were fabricated from aluminum, 304 stainless steel, and oxygen-free copper. Initially, coupon samples were cleaned and passed preliminary testing for the proposed process. Next, beam tube samples of each material were cleaned, and the PSD measured on beam line U10B using white light with a critical energy of 487 eV. Prior to cleaning, the samples were contaminated with a mixture of cutting oils, lubricants, vacuum oils, and vacuum grease. The contaminated samples were then baked. Samples of each material were also cleaned with the existing process after the same preparation. Beam tube samples were exposed to between 1022 and 1023 photons per meter for a PSD measurement. Desorption yields for H2, CO, CO2, CH4, and H2O are reported for both the existing cleaning and for the replacement cleaning process. Preliminary data, residual gas scans, and PSD results are given and discussed. The new process is also compared with new cleaning methods developed in other laboratories. After modification, the new UHV cleaning process was accepted by BNL

  17. Tandem accelerators

    After the installation of Ti-acceleration tubes and substantial modifications and additions to the EN tandem accelerator the performance of the machine has stabilized. The voltage behaviour of the tubes obviously improves as conditioning times necessary to run up to 6 MV decrease. A gridded lens has been added at the entrance of the first acceleration tube, and a second foil stripper is now installed in the short dead section between the high-energy tubes. The MP tandem also has been running stably during most of the year. However, beam instabilities originating from the last tube section and wear problems at the low-energy set of pelletron-chains caused some loss of beam time. During the fall, one set of pelletron charging chains has to be replaced after 49,000 hours of operation. In the course of the year, the MP and the EN tandem accelerators finished their 100,000th and 150,000th hours of operations, respectively. Preparations for the installation of the 3 MV negative heavy ion injector for the MP are progressing steadily. External beam transport, terminal ion optics, and data acquisition and control systems are to a major extent completed; the integration of the terminal power supplies has started. After the final assembly of the accelerator column structure, first voltage runs can be performed. (orig.)

  18. High-Temperature Oxidation of Cr-Mo Steels and Its Relevance to Accelerated Rupture Testing and Life Assessment of In-Service Components

    Singh Raman, R. K.; Al-Mazrouee, A.

    2007-08-01

    Use of accelerated creep rupture testing to assess the remaining life of components operating at elevated temperatures, such as pipes and tubes, is a common practice. At high temperatures, oxide growth can affect the creep results by diameter reduction and thus can increase the stress. However, the nature of oxide layer and hence oxidation behavior can be affected by minor changes in alloying composition of steels. This article presents the study of oxide-scale growth and specimen diameter reduction kinetics during oxidation of two Cr-Mo steels used in the manufacture of boiler tubing. Oxidation tests were carried out on 1.25Cr-0.5Mo and 2.25Cr-1Mo steels at 600 °C and 700 °C for times up to 1000 hours, using cylindrical specimens (similar to those used for creep testing). At 600 °C, the oxidation resistance of 2.25Cr-1Mo steel was superior to 1.25Cr-0.5Mo steel. However, the oxidation resistance of the two steels at 700 °C was similar in spite of the difference in their Cr contents. Multilayer oxide scales of oxides with various compositions were observed to have formed over the two steels. The similarity in oxidation kinetics of the two steels at 700 °C (in spite of differences in Cr contents) is ascribed to their Si contents and the predominant role of Si in oxidation at this temperature. The article also discusses implications of the variation in the oxidation kinetics to the stress enhancement in creep specimens due to scaling losses, and possible inaccuracies in creep data, as a result of minor variations in alloying composition.

  19. Biokinetics and radiation dosimetry of 14C-labelled triolein, urea, glycocholic acid and xylose in man. Studies related to nuclear medicine 'breath tests' using accelerator mass spectrometry

    14C-labelled substances have been used in biomedical research and clinical medicine for over 50 years. Physicians and scientists however, often hesitate to use these substances in patients and volunteers because the radiation dosimetry is unclear. In this work detailed long-term biokinetic and dosimetric estimation have been carried out for four clinically used 14C-breath tests: 14C-triolein (examination of fat malabsorption), urea (detection of Helicobacter pylori infection in the stomach), glycocholic acid and xylose (examination of bacterial overgrowth in the small intestine) by using the highly sensitive accelerator mass-spectrometry (AMS) technique. The AMS technique has been used to measure low 14C concentrations in small samples of exhaled air, urine, faeces and tissue samples and has improved the base for the estimation of the absorbed dose to various organs and tissues and the effective dose to man. The high sensitivity of the AMS system has also made it possible to perform 14C breath tests on patient groups which were earlier subject for restriction (e.g. small children). In summary, our results show that for adult patients - and in the case of 14C-urea breath test also for children down to 3 years of age - the dose contributions are comparatively low, both described as organ doses and as effective doses. For adults, the latter is: 14C-glycocholic acid - 0.4 mSv/MBq, 14C-triolein - 0.3 mSv/MBq, 14C-xylose - 0.1 mSv/MBq and 14C-urea - 0.04 mSv/MBq. Thus, from a radiation protection point of view there is no reason for restrictions in using any of the 14C-labelled radiopharmaceutical included in this work in the activities normally used (0.07-0.2 MBq for a 70 kg patient)

  20. APT accelerator technology

    The proposed accelerator production of tritium (APT) project requires an accelerator that provides a cw proton beam of 100 m A at 1300 MeV. Since the majority of the technical risk of a high-current cw (continuous-wave, 100% DF) accelerator resides in the low-energy section, Los Alamos is building a 20 MeV duplicate of the accelerator front end to confirm design codes, beam performance, and demonstrate operational reliability. We report on design details of this low-energy demonstration accelerator (LEDA) and discuss the integrated design of the full accelerator for the APT plant. LEDA's proton injector is under test and has produced more than 130 mA at 75 keV. Fabrication is proceeding on a 6.7- MeV, 8-meter-long RFQ, and detailed design is underway on coupled-cavity drift-tube linac (CCDTL) structures. In addition, detailed design and technology experiments are underway on medium-beta superconducting cavities to assess the feasibility of replacing the conventional (room-temperature copper) high-energy linac with a linac made of niobium superconducting RF cavities. (author)