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Sample records for accelerator injection control

  1. Controlling electron injection in laser plasma accelerators using multiple pulses

    SciTech Connect

    Matlis, N. H.; Geddes, C. G. R.; Plateau, G. R.; Esarey, E.; Schroeder, C.; Bruhwiler, D.; Cormier-Michel, E.; Chen, M.; Yu, L.; Leemans, W. P.

    2012-12-21

    Use of counter-propagating pulses to control electron injection in laser-plasma accelerators promises to be an important ingredient in the development of stable devices. We discuss the colliding pulse scheme and associated diagnostics.

  2. Colliding Laser Pulses for Laser-Plasma Accelerator Injection Control

    SciTech Connect

    Plateau, G. R.; Geddes, C. G. R.; Matlis, N. H.; Mittelberger, D. E.; Nakamura, K.; Schroeder, C. B.; Esarey, E.; Leemans, W. P.; Cormier-Michel, E.

    2010-11-04

    Decoupling injection from acceleration is a key challenge to achieve compact, reliable, tunable laser-plasma accelerators (LPA). In colliding pulse injection the beat between multiple laser pulses can be used to control energy, energy spread, and emittance of the electron beam by injecting electrons in momentum and phase into the accelerating phase of the wake trailing the driver laser pulse. At LBNL, using automated control of spatiotemporal overlap of laser pulses, two-pulse experiments showed stable operation and reproducibility over hours of operation. Arrival time of the colliding beam was scanned, and the measured timing window and density of optimal operation agree with simulations. The accelerator length was mapped by scanning the collision point.

  3. Colliding Laser Pulses for Laser-Plasma Accelerator Injection Control

    NASA Astrophysics Data System (ADS)

    Plateau, G. R.; Geddes, C. G. R.; Matlis, N. H.; Cormier-Michel, E.; Mittelberger, D. E.; Nakamura, K.; Schroeder, C. B.; Esarey, E.; Leemans, W. P.

    2010-11-01

    Decoupling injection from acceleration is a key challenge to achieve compact, reliable, tunable laser-plasma accelerators (LPA) [1, 2]. In colliding pulse injection the beat between multiple laser pulses can be used to control energy, energy spread, and emittance of the electron beam by injecting electrons in momentum and phase into the accelerating phase of the wake trailing the driver laser pulse [3, 4, 5, 6, 7]. At LBNL, using automated control of spatiotemporal overlap of laser pulses, two-pulse experiments showed stable operation and reproducibility over hours of operation. Arrival time of the colliding beam was scanned, and the measured timing window and density of optimal operation agree with simulations [8]. The accelerator length was mapped by scanning the collision point.

  4. Control of seeding phase for a cascaded laser wakefield accelerator with gradient injection

    SciTech Connect

    Wang, Wentao; Li, Wentao; Liu, Jiansheng; Wang, Cheng; Chen, Qiang; Zhang, Zhijun; Qi, Rong; Leng, Yuxin; Liang, Xiaoyan; Liu, Yanqi; Lu, Xiaoming; Wang, Cheng; Li, Ruxin; Xu, Zhizhan

    2013-12-09

    We demonstrated experimentally the seeding-phase control for a two-stage laser wakefield accelerator with gradient injection. By optimizing the seeding phase of electrons into the second stage, electron beams beyond 0.5 GeV with a 3% rms energy spread were produced over a short acceleration distance of ∼2 mm. Peak energy of the electron beam was further extended beyond 1 GeV by lengthening the second acceleration stage to 5 mm. Time-resolved magnetic field measurements via magneto-optical Faraday polarimetry allowed us to monitor the processes of electron seeding and acceleration in the second stage.

  5. Controlled injection and acceleration of electrons in plasma wakefields by colliding laser pulses.

    PubMed

    Faure, J; Rechatin, C; Norlin, A; Lifschitz, A; Glinec, Y; Malka, V

    2006-12-01

    In laser-plasma-based accelerators, an intense laser pulse drives a large electric field (the wakefield) which accelerates particles to high energies in distances much shorter than in conventional accelerators. These high acceleration gradients, of a few hundreds of gigavolts per metre, hold the promise of compact high-energy particle accelerators. Recently, several experiments have shown that laser-plasma accelerators can produce high-quality electron beams, with quasi-monoenergetic energy distributions at the 100 MeV level. However, these beams do not have the stability and reproducibility that are required for applications. This is because the mechanism responsible for injecting electrons into the wakefield is based on highly nonlinear phenomena, and is therefore hard to control. Here we demonstrate that the injection and subsequent acceleration of electrons can be controlled by using a second laser pulse. The collision of the two laser pulses provides a pre-acceleration stage which provokes the injection of electrons into the wakefield. The experimental results show that the electron beams obtained in this manner are collimated (5 mrad divergence), monoenergetic (with energy spread <10 per cent), tuneable (between 15 and 250 MeV) and, most importantly, stable. In addition, the experimental observations are compatible with electron bunch durations shorter than 10 fs. We anticipate that this stable and compact electron source will have a strong impact on applications requiring short bunches, such as the femtolysis of water, or high stability, such as radiotherapy with high-energy electrons or radiography for materials science. PMID:17151663

  6. Controlled Electron Injection into Plasma Accelerators and SpaceCharge Estimates

    SciTech Connect

    Fubiani, Gwenael J.

    2005-09-01

    Plasma based accelerators are capable of producing electron sources which are ultra-compact (a few microns) and high energies (up to hundreds of MeVs) in much shorter distances than conventional accelerators. This is due to the large longitudinal electric field that can be excited without the limitation of breakdown as in RF structures.The characteristic scale length of the accelerating field is the plasma wavelength and for typical densities ranging from 1018 - 1019 cm-3, the accelerating fields and scale length can hence be on the order of 10-100GV/m and 10-40 mu m, respectively. The production of quasimonoenergetic beams was recently obtained in a regime relying on self-trapping of background plasma electrons, using a single laser pulse for wakefield generation. In this dissertation, we study the controlled injection via the beating of two lasers (the pump laser pulse creating the plasma wave and a second beam being propagated in opposite direction) which induce a localized injection of background plasma electrons. The aim of this dissertation is to describe in detail the physics of optical injection using two lasers, the characteristics of the electron beams produced (the micrometer scale plasma wavelength can result in femtosecond and even attosecond bunches) as well as a concise estimate of the effects of space charge on the dynamics of an ultra-dense electron bunch with a large energy spread.

  7. Controlled laser plasma wakefield acceleration of electrons via colliding pulse injection in non-collinear geometry

    NASA Astrophysics Data System (ADS)

    Toth, Csaba; Nakamura, Kei; Geddes, Cameron; Panasenko, Dmitriy; Plateau, Guillaume; Matlis, Nicholas; Schroeder, Carl; Esarey, Eric; Leemans, Wim

    2007-11-01

    Colliding laser pulses [1] have been proposed as a method for controlling injection of electrons into a laser wakefield accelerator (LWFA) and hence producing high quality electron beams with energy spread below 1% and normalized emittances < 1 micron. The. One pulse excites a plasma wake, and a collinear pulse following behind it collides with a counterpropagating pulse forming a beat pattern that boosts background electrons into accelerating phase. A variation of the original method uses only two laser pulses [2] which may be non-collinear. The first pulse drives the wake, and beating of the trailing edge of this pulse with the colliding pulse injects electrons. Non-collinear injection avoids optical elements on the electron beam path (avoiding emittance growth). We report on progress of non-collinear experiments at LBNL, using the Ti:Sapphire laser at the LOASIS facility of LBNL. New results indicate that the electron beam properties are affected by the presence of the second beam. [1] E. Esarey, et al, Phys. Rev. Lett 79, 2682 (1997) [2] G. Fubiani, Phys. Rev. E 70, 016402 (2004)

  8. Optical control of hard X-ray polarization by electron injection in a laser wakefield accelerator

    PubMed Central

    Schnell, Michael; Sävert, Alexander; Uschmann, Ingo; Reuter, Maria; Nicolai, Maria; Kämpfer, Tino; Landgraf, Björn; Jäckel, Oliver; Jansen, Oliver; Pukhov, Alexander; Kaluza, Malte Christoph; Spielmann, Christian

    2013-01-01

    Laser-plasma particle accelerators could provide more compact sources of high-energy radiation than conventional accelerators. Moreover, because they deliver radiation in femtosecond pulses, they could improve the time resolution of X-ray absorption techniques. Here we show that we can measure and control the polarization of ultra-short, broad-band keV photon pulses emitted from a laser-plasma-based betatron source. The electron trajectories and hence the polarization of the emitted X-rays are experimentally controlled by the pulse-front tilt of the driving laser pulses. Particle-in-cell simulations show that an asymmetric plasma wave can be driven by a tilted pulse front and a non-symmetric intensity distribution of the focal spot. Both lead to a notable off-axis electron injection followed by collective electron–betatron oscillations. We expect that our method for an all-optical steering is not only useful for plasma-based X-ray sources but also has significance for future laser-based particle accelerators. PMID:24026068

  9. Enhanced single-stage laser-driven electron acceleration by self-controlled ionization injection.

    PubMed

    Li, Song; Hafz, Nasr A M; Mirzaie, Mohammad; Sokollik, Thomas; Zeng, Ming; Chen, Min; Sheng, Zhengming; Zhang, Jie

    2014-12-01

    We report on overall enhancement of a single-stage laser wakefield acceleration (LWFA) using the ionization injection in a mixture of 0.3% nitrogen gas in 99.7% helium gas. Upon the interaction of 30-TW, 30-fs laser pulses with a gas jet of the above gas mixture, >300 MeV electron beams were generated at a helium plasma densities of 3.3-8.5 × 10(18) cm(-3). Compared with the uncontrolled electron self-injection in pure helium gas jet, the ionization injection process due to the presence of ultra-low nitrogen concentrations appears to be self-controlled; it has led to the generation of electron beams with higher energies, higher charge, lower density threshold for trapping, and a narrower energy spread without dark current (low energy electrons) or multiple bunches. It is foreseen that further optimization of such a scheme is expected to bring the electron beam energy-spread down to 1%, making them suitable for driving ultra-compact free-electron lasers. PMID:25606890

  10. Colliding pulse injection experiments in non-collinear geometryfor controlled laser plasma wakefield acceleration of electrons

    SciTech Connect

    Toth, Carl B.; Esarey, Eric H.; Geddes, Cameron G.R.; Leemans,Wim P.; Nakamura, Kei; Panasenko, Dmitriy; Schroeder, Carl B.; Bruhwiler,D.; Cary, J.R.

    2007-06-25

    An optical injection scheme for a laser-plasma basedaccelerator which employs a non-collinear counter-propagating laser beamto push background electrons in the focusing and acceleration phase viaponderomotive beat with the trailing part of the wakefield driver pulseis discussed. Preliminary experiments were performed using a drive beamof a_0 = 2.6 and colliding beam of a_1 = 0.8 both focused on the middleof a 200 mu m slit jet backed with 20 bar, which provided ~; 260 mu mlong gas plume. The enhancement in the total charge by the collidingpulse was observed with sharp dependence on the delay time of thecolliding beam. Enhancement of the neutron yield was also measured, whichsuggests a generation of electrons above 10 MeV.

  11. Stable Electron Beams With Low Absolute Energy Spread From a LaserWakefield Accelerator With Plasma Density Ramp Controlled Injection

    SciTech Connect

    Geddes, Cameron G.R.; Cormier-Michel, E.; Esarey, E.; Leemans,W.P.; Nakamura, K.; Panasenko, D.; Plateau, Guillaume R.; Schroeder, CarlB.; Toth, Csaba; Cary, J.R.

    2007-06-25

    Laser wakefield accelerators produce accelerating gradientsup to hundreds of GeV/m, and recently demonstrated 1-10 MeV energy spreadat energies up to 1 GeV using electrons self-trapped from the plasma.Controlled injection and staging may further improve beam quality bycircumventing tradeoffs between energy, stability, and energyspread/emittance. We present experiments demonstrating production of astable electron beam near 1 MeV with hundred-keV level energy spread andcentral energy stability by using the plasma density profile to controlselfinjection, and supporting simulations. Simulations indicate that suchbeams can be post accelerated to high energies,potentially reducingmomentum spread in laser acceleratorsby 100-fold or more.

  12. Colliding pulse injection experiments in non-collinear geometry for controlled laser plasma wakefield acceleration of electrons

    NASA Astrophysics Data System (ADS)

    Toth, Csaba; Nakamura, K.; Geddes, C.; Michel, P.; Schroeder, C.; Esarey, E.; Leemans, W.

    2006-10-01

    A method for controlled injection of electrons into a plasma wakefield relying on colliding laser pulses [1] has been proposed a decade ago to produce high quality relativistic electron beams with energy spread below 1% and normalized emittances < 1 micron from a laser wakefield accelerator (LWFA). The original idea uses three pulses in which one pulse excites the plasma wake and a trailing laser pulse collides with a counterpropagating one to form a beat pattern that boosts background electrons to catch the plasma wave. Another, two-beam off-axis injection method [2] with crossing angles varying from 180 to 90 degrees avoids having optical elements on the path of the electron beam and has been studied at the LOASIS facility of LBNL as a viable method for laser triggered injection. It allows low dark current operation with controllable final beam energy and low energy spread. Here, we report on progress of electron optical injection via the two-beam non-collinear colliding pulse scheme using multi-terawatt Ti:Sapphire laser beams (45 fs, 100s of mJ) focused onto a Hydrogen gas plume. Experimental results indicate that electron beam properties are affected by the second beam. *This work is supported by DoE under contract DE-AC02-05CH11231. [1] E. Esarey, et al, Phys. Rev. Lett 79, 2682 (1997) [2] G. Fubiani, Phys. Rev. E 70, 016402 (2004)

  13. Sequential injection gas guns for accelerating projectiles

    DOEpatents

    Lacy, Jeffrey M.; Chu, Henry S.; Novascone, Stephen R.

    2011-11-15

    Gas guns and methods for accelerating projectiles through such gas guns are described. More particularly, gas guns having a first injection port located proximate a breech end of a barrel and a second injection port located longitudinally between the first injection port and a muzzle end of the barrel are described. Additionally, modular gas guns that include a plurality of modules are described, wherein each module may include a barrel segment having one or more longitudinally spaced injection ports. Also, methods of accelerating a projectile through a gas gun, such as injecting a first pressurized gas into a barrel through a first injection port to accelerate the projectile and propel the projectile down the barrel past a second injection port and injecting a second pressurized gas into the barrel through the second injection port after passage of the projectile and to further accelerate the projectile are described.

  14. Charge Accretion Rate and Injection Radius of Ionized-Induced Injections in Laser Wakefield Accelerators

    NASA Astrophysics Data System (ADS)

    Zeng, Ming; Chen, Min; Sheng, Zheng-Ming

    2016-03-01

    Ionization-induced injection has recently been proved to be a stable injection method with several advantages in laser wakefield accelerators. However, the controlling of this injection process aiming at producing high quality electron beams is still challenging. In this paper, we examine the ionization injection processes and estimate the injection rate with two-dimensional particle-in-cell simulations. The injection rate is shown to increase linearly with the high-Z gas density as long as its ratio is smaller than some threshold in the mix gases. It is also shown that by changing the transverse mode of the driving lasers one can control the injection rate.

  15. A side-injected-laser plasma accelerator

    SciTech Connect

    Katsouleas, T.; Dawson, J.M.; Sultana, D.; Yun, Y.T.

    1985-10-01

    A new method for driving relativistic plasma waves capable of ultra-high acceleration gradients (order 1GeV/cm) is presented. By injecting a single laser frequency from the side, rather than colinearly with the accelerated particles, both pump depletion and particle dephasing may be avoidable. The coupling of the side injected laser to the relativistic plasma wave via a pre-formed density ripple in the plasma is modelled analytically and with computer simulation.

  16. KEKB accelerator control system

    NASA Astrophysics Data System (ADS)

    Akasaka, Nobumasa; Akiyama, Atsuyoshi; Araki, Sakae; Furukawa, Kazuro; Katoh, Tadahiko; Kawamoto, Takashi; Komada, Ichitaka; Kudo, Kikuo; Naito, Takashi; Nakamura, Tatsuro; Odagiri, Jun-ichi; Ohnishi, Yukiyoshi; Sato, Masayuki; Suetake, Masaaki; Takeda, Shigeru; Takeuchi, Yasunori; Yamamoto, Noboru; Yoshioka, Masakazu; Kikutani, Eji

    2003-02-01

    The KEKB accelerator control system including a control computer system, a timing distribution system, and a safety control system are described. KEKB accelerators were installed in the same tunnel where the TRISTAN accelerator was. There were some constraints due to the reused equipment. The control system is based on Experimental Physics and Industrial Control System (EPICS). In order to reduce the cost and labor for constructing the KEKB control system, as many CAMAC modules as possible are used again. The guiding principles of the KEKB control computer system are as follows: use EPICS as the controls environment, provide a two-language system for developing application programs, use VMEbus as frontend computers as a consequence of EPICS, use standard buses, such as CAMAC, GPIB, VXIbus, ARCNET, RS-232 as field buses and use ergonomic equipment for operators and scientists. On the software side, interpretive Python and SAD languages are used for coding application programs. The purpose of the radiation safety system is to protect personnel from radiation hazards. It consists of an access control system and a beam interlock system. The access control system protects people from strong radiation inside the accelerator tunnel due to an intense beam, by controlling access to the beamline area. On the other hand, the beam interlock system prevents people from radiation exposure by interlocking the beam operation. For the convenience of accelerator operation and access control, the region covered by the safety system is divided into three major access control areas: the KEKB area, the PF-AR area, and the beam-transport (BT) area. The KEKB control system required a new timing system to match a low longitudinal acceptance due to a low-alpha machine. This timing system is based on a frequency divider/multiply technique and a digital delay technique. The RF frequency of the KEKB rings and that of the injector Linac are locked with a common divisor frequency. The common

  17. Laser wakefield acceleration: the injection issue. Overview and latest results.

    PubMed

    van der Wiel, M J; Luiten, O J; Brussaard, G J H; van der Geer, S B; Urbanus, W H; van Dijk, W; van Oudheusden, Th

    2006-03-15

    External injection of electron bunches into laser-driven plasma waves so far has not resulted in 'controlled' acceleration, i.e. production of bunches with well-defined energy spread. Recent simulations, however, predict that narrow distributions can be achieved, provided the conditions for properly trapping the injected electrons are met. Under these conditions, injected bunch lengths of one to several plasma wavelengths are acceptable. This paper first describes current efforts to demonstrate this experimentally, using state-of-the-art radio frequency technology. The expected charge accelerated, however, is still low for most applications. In the second part, the paper addresses a number of novel concepts for significant enhancement of photo-injector brightness. Simulations predict that, once these concepts are realized, external injection into a wakefield accelerator will lead to accelerated bunch specs comparable to those of recent 'laser-into-gasjet' experiments, without the present irreproducibility of charge and final energy of the latter. PMID:16483957

  18. Injection-controlled laser resonator

    DOEpatents

    Chang, J.J.

    1995-07-18

    A new injection-controlled laser resonator incorporates self-filtering and self-imaging characteristics with an efficient injection scheme. A low-divergence laser signal is injected into the resonator, which enables the injection signal to be converted to the desired resonator modes before the main laser pulse starts. This injection technique and resonator design enable the laser cavity to improve the quality of the injection signal through self-filtering before the main laser pulse starts. The self-imaging property of the present resonator reduces the cavity induced diffraction effects and, in turn, improves the laser beam quality. 5 figs.

  19. Injection-controlled laser resonator

    DOEpatents

    Chang, Jim J.

    1995-07-18

    A new injection-controlled laser resonator incorporates self-filtering and self-imaging characteristics with an efficient injection scheme. A low-divergence laser signal is injected into the resonator, which enables the injection signal to be converted to the desired resonator modes before the main laser pulse starts. This injection technique and resonator design enable the laser cavity to improve the quality of the injection signal through self-filtering before the main laser pulse starts. The self-imaging property of the present resonator reduces the cavity induced diffraction effects and, in turn, improves the laser beam quality.

  20. Broadband accelerator control network

    SciTech Connect

    Skelly, J.; Clifford, T.; Frankel, R.

    1983-01-01

    A broadband data communications network has been implemented at BNL for control of the Alternating Gradient Synchrotron (AG) proton accelerator, using commercial CATV hardware, dual coaxial cables as the communications medium, and spanning 2.0 km. A 4 MHz bandwidth Digital Control channel using CSMA-CA protocol is provided for digital data transmission, with 8 access nodes available over the length of the RELWAY. Each node consists of an rf modem and a microprocessor-based store-and-forward message handler which interfaces the RELWAY to a branch line implemented in GPIB. A gateway to the RELWAY control channel for the (preexisting) AGS Computerized Accelerator Operating system has been constructed using an LSI-11/23 microprocessor as a device in a GPIB branch line. A multilayer communications protocol has been defined for the Digital Control Channel, based on the ISO Open Systems Interconnect layered model, and a RELWAY Device Language defined as the required universal language for device control on this channel.

  1. Adaptive control for accelerators

    DOEpatents

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

    1991-01-01

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

  2. Optical transverse injection in laser-plasma acceleration.

    PubMed

    Lehe, R; Lifschitz, A F; Davoine, X; Thaury, C; Malka, V

    2013-08-23

    Laser-wakefield acceleration constitutes a promising technology for future electron accelerators. A crucial step in such an accelerator is the injection of electrons into the wakefield, which will largely determine the properties of the extracted beam. We present here a new paradigm of colliding-pulse injection, which allows us to generate high-quality electron bunches having both a very low emittance (0.17 mm·mrad) and a low energy spread (2%), while retaining a high charge (~100 pC) and a short duration (3 fs). In this paradigm, the pulse collision provokes a transient expansion of the accelerating bubble, which then leads to transverse electron injection. This mechanism contrasts with previously observed optical injection mechanisms, which were essentially longitudinal. We also specify the range of parameters in which this new type of injection occurs and show that it is within reach of existing high-intensity laser facilities. PMID:24010450

  3. Remote sensing of plasma injection and acceleration phenomena

    SciTech Connect

    Burch, J.L.

    1985-01-01

    Dynamics Explorer-1 High Altitude Plasma Instrument data have been used to investigate the injection of magnetosheath plasma into the polar cusp, the injection of auroral ion beams into the magnetosphere, and the acceleration of electrons transverse to the magnetic field direction, and the results are discussed. In the case of polar cusp plasmas, it is found that injection occurs at the high-latitude magnetopause, at geocentric distances near eight earth radii. In the case of auroral ion beams it is determined that ion bands are not produced by equatorial injection from the plasma sheet, but by the upward acceleration of ions from auroral acceleration regions. Finally, conical electron distributions are found to be consistent with transverse acceleration at altitudes of a thousand or more km, within or below the magnetic-field-aligned potential drops of the auroral acceleration regions.

  4. Tomography of injection and acceleration of monoenergetic electrons in a laser-wakefield accelerator.

    PubMed

    Hsieh, C-T; Huang, C-M; Chang, C-L; Ho, Y-C; Chen, Y-S; Lin, J-Y; Wang, J; Chen, S-Y

    2006-03-10

    A tomographic diagnosis method was developed to systematically resolve the injection and acceleration processes of a monoenergetic electron beam in a laser-wakefield accelerator. It was found that all the monoenergetic electrons are injected at the same location in the plasma column and accelerated from 5 to 55 MeV energy in 200 microm distance. This is a direct measurement of the real acceleration gradient in a laser-wakefield accelerator, and the experimental data are consistent with the model of transverse wave breaking and beam loading for monoenergetic electron injection. PMID:16606269

  5. Laser wakefield and direct acceleration with ionization injection

    NASA Astrophysics Data System (ADS)

    Zhang, Xi; Khudik, Vladimir N.; Pukhov, Alexander; Shvets, Gennady

    2016-03-01

    We demonstrate using particle-in-cell simulations that electrons can be injected into a hybrid laser wakefield and direct laser accelerator via ionization injection. We propose an accelerator and injector scenario that utilizes two laser pulses. The first (pump) pulse produces the plasma ‘bubble’ by expelling the plasma electrons generated by its leading edge from the low-Z component of the gas mixture, and then injects electrons into the bubble by ionizing the high-Z component. The second time-delayed laser pulse resonantly interacts with these injected electrons undergoing betatron oscillations inside the bubble. We show that the electrons ionized off-axis and on-axis but off the peak ionization phase possess sufficient transverse energy to undergo efficient direct laser acceleration (DLA). When combined with their acceleration by the bubble’s longitudinal plasma wake, DLA can double the total energy gain and produce a monoenergetic beam.

  6. Quasi-stable injection channels in a wakefield accelerator

    NASA Astrophysics Data System (ADS)

    Wiltshire-Turkay, Mara; Farmer, John P.; Pukhov, Alexander

    2016-05-01

    The influence of initial position on the acceleration of externally injected electrons in a plasma wakefield is investigated. Test-particle simulations show previously unobserved complex structure in the parameter space, with quasi-stable injection channels forming for particles injected in narrow regions away from the wake centre. Particles injected into these channels remain in the wake for a considerable time after dephasing and as a result achieve significantly higher energy than their neighbours. The result is relevant to both the planning and optimisation of experiments making use of external injection.

  7. Acceleration of nonmonoenergetic electron bunches injected into a wake wave

    SciTech Connect

    Kuznetsov, S. V.

    2012-07-15

    The trapping and acceleration of nonmonoenergetic electron bunches in a wake field wave excited by a laser pulse in a plasma channel is studied. Electrons are injected into the region of the wake wave potential maximum at a velocity lower than the phase velocity of the wave. The paper analyzes the grouping of bunch electrons in the energy space emerging in the course of acceleration under certain conditions of their injection into the wake wave and minimizing the energy spread for such electrons. The factors determining the minimal energy spread between bunch electrons are analyzed. The possibility of monoenergetic acceleration of electron bunches generated by modern injectors in a wake wave is analyzed.

  8. Shock assisted ionization injection in laser-plasma accelerators

    PubMed Central

    Thaury, C.; Guillaume, E.; Lifschitz, A.; Ta Phuoc, K.; Hansson, M.; Grittani, G.; Gautier, J.; Goddet, J.-P.; Tafzi, A.; Lundh, O.; Malka, V.

    2015-01-01

    Ionization injection is a simple and efficient method to trap an electron beam in a laser plasma accelerator. Yet, because of a long injection length, this injection technique leads generally to the production of large energy spread electron beams. Here, we propose to use a shock front transition to localize the injection. Experimental results show that the energy spread can be reduced down to 10 MeV and that the beam energy can be tuned by varying the position of the shock. This simple technique leads to very stable and reliable injection even for modest laser energy. It should therefore become a unique tool for the development of laser-plasma accelerators. PMID:26549584

  9. Shock assisted ionization injection in laser-plasma accelerators.

    PubMed

    Thaury, C; Guillaume, E; Lifschitz, A; Ta Phuoc, K; Hansson, M; Grittani, G; Gautier, J; Goddet, J-P; Tafzi, A; Lundh, O; Malka, V

    2015-01-01

    Ionization injection is a simple and efficient method to trap an electron beam in a laser plasma accelerator. Yet, because of a long injection length, this injection technique leads generally to the production of large energy spread electron beams. Here, we propose to use a shock front transition to localize the injection. Experimental results show that the energy spread can be reduced down to 10 MeV and that the beam energy can be tuned by varying the position of the shock. This simple technique leads to very stable and reliable injection even for modest laser energy. It should therefore become a unique tool for the development of laser-plasma accelerators. PMID:26549584

  10. Vibration control in accelerators

    SciTech Connect

    Montag, C.

    2011-01-01

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

  11. Injection and acceleration of Au31+ in the BNL AGS.

    SciTech Connect

    Fischer,W.; Ahrens, L.; Brown, K.; Gardner, C.; Glenn, W.; Huang, H.; Mapes, M.; Smart, L.; Thieberger, P.; Tsoupas, N.; Zhang, S.Y.; Zeno, K.; Omet, C.; Spiller, P.

    2008-06-23

    Injection and acceleration of ions in a lower charge state reduces space charge effects, and, if further elcctron stripping is needed, may allow elimination of a stripping stage and the associated beam losses. The former is of interest to the accelerators in the GSI FAIR complex, the latter for BNL RHIC collider operation at energies lower than the current injection energy. Lower charge state ions, however, have a higher likelihood of electron stripping which can lead to dynamic pressures rises and subsequent beam losses. We report on experiments in the AGS where Au{sup 31+} ions were injected and accelerated instead of the normally used Au{sup 77+} ions. Beam intensities and the average pressure in the AGS ring are recorded, and compared with calculations for dynamic pressures and beam losses. The experimental results will be used to benchmark the StrahlSim dynamic vacuum code and will be incorporated in the GSI FAIR SIS100 design.

  12. Acceleration of electron bunches injected into a wake wave

    SciTech Connect

    Kuznetsov, S. V.

    2012-02-15

    The process of trapping and acceleration of nonmonoenergetic electron bunches by a wake wave excited by a laser pulse in a plasma channel is investigated. The electrons are injected into the vicinity of the maximum of the wakefield potential with a velocity lower than the wave phase velocity. The study is aimed at utilizing specific features of a wakefield with substantially overlapped focusing and accelerating phases for achieving monoenergetic electron acceleration. Conditions are found under which electrons in a finite-length nonmonoenergetic bunch are accelerated to high energies, while the energy spread between them is minimal. The effect of energy grouping of electrons makes it possible to obtain compact high-energy electron bunches with a small energy spread during laser plasma acceleration.

  13. Laser Triggered Electron Injection into a Channel Guided Wakefield Accelerator

    NASA Astrophysics Data System (ADS)

    Nakamura, K.; Filip, C.

    2005-10-01

    Laser-plasma accelerators have demonstrated the generation of narrow energy spread (˜ few %) electron beams with considerable amount of charge (>100 pC). Stability of laser-plasma accelerators, as in the conventional accelerators, requires highly synchronized injection of electrons into the structured accelerating field. The Colliding Pulse Method[1] with pre-formed plasma channel guiding [2] can result in jitter-free injection in a dark-current-free accelerating structure. We report on experimental progress of laser triggered injection of electrons into a laser wakefield, where an intense laser pulse is guided by a pre-formed plasma channel. The experiments use the multi-beam, multi-terawatt Ti:Al2O3 laser at LOASIS facility of LBNL. The ignitor-heater method is used to first produce a pre-formed plasma channel in a hydrogen gas jet. Two counter propagating beams (wakefield driver:100-500mJ-50fs, injector:50-300mJ-50fs) then are focused onto the entrance of the channel. Preliminary results indicate that electron beam properties are affected by the second beam. Details of the experiment will be presented. [1]G.Fubiani, et al, Phys. Rev. E 70, 016402 (2004). [2]C.G.R. Geddes et al, Nature 431, 538 (2004). This work is supported by DoE under contract DE-AC02-05CH11231.

  14. A tracking code for injection and acceleration studies in synchrotrons

    SciTech Connect

    Lessner, E.; Symon, K. |

    1996-11-01

    CAPTURE-SPC is a Monte-Carlo-based tracking program that simulates the injection and acceleration processes in proton synchrotrons. The time evolution of a distribution of charged particles is implemented by a symplectic, second-order-accurate integration algorithm. The recurrence relations follow a time-stepping leap--frog method. The time-step can be varied optionally to reduce computer time. Space-charge forces are calculated by binning the phase-projected particle distribution. The statistical fluctuations introduced by the binning process are reduced by presmoothing the data by the cloud-in-cell method and by filtering. Both the bin size and amount of filtering can be varied during the acceleration cycle so that the bunch fine structure is retained while the short wavelength noise is attenuated. The initial coordinates of each macro particle together with its time of injection are retained throughout the calculations. This information is useful in determining low-loss injection schemes.

  15. All-optical cascaded laser wakefield accelerator using ionization-induced injection.

    PubMed

    Liu, J S; Xia, C Q; Wang, W T; Lu, H Y; Wang, Ch; Deng, A H; Li, W T; Zhang, H; Liang, X Y; Leng, Y X; Lu, X M; Wang, C; Wang, J Z; Nakajima, K; Li, R X; Xu, Z Z

    2011-07-15

    We report on near-GeV electron beam generation from an all-optical cascaded laser wakefield accelerator (LWFA). Electron injection and acceleration are successfully separated and controlled in different LWFA stages by employing two gas cells filled with a He/O2 mixture and pure He gas, respectively. Electrons with a Maxwellian spectrum, generated from the first LWFA assisted by ionization-induced injection, were seeded into the second LWFA with a 3-mm-thick gas cell and accelerated to be a 0.8-GeV quasimonoenergetic electron beam, corresponding to an acceleration gradient of 187  GV/m. The demonstrated scheme paves the way towards the multi-GeV laser accelerators. PMID:21838367

  16. Robust control of accelerators

    SciTech Connect

    Johnson, W.J.D. ); Abdallah, C.T. )

    1990-01-01

    The problem of controlling the variations in the rf power system can be effectively cast as an application of modern control theory. Two components of this theory are obtaining a model and a feedback structure. The model inaccuracies influence the choice of a particular controller structure. Because of the modeling uncertainty, one has to design either a variable, adaptive controller or a fixed, robust controller to achieve the desired objective. The adaptive control scheme usually results in very complex hardware; and, therefore, shall not be pursued in this research. In contrast, the robust control methods leads to simpler hardware. However, robust control requires a more accurate mathematical model of the physical process than is required by adaptive control. Our research at the Los Alamos National Laboratory (LANL) and the University of New Mexico (UNM) has led to the development and implementation of a new robust rf power feedback system. In this paper, we report on our research progress. In section one, the robust control problem for the rf power system and the philosophy adopted for the beginning phase of our research is presented. In section two, the results of our proof-of-principle experiments are presented. In section three, we describe the actual controller configuration that is used in LANL FEL physics experiments. The novelty of our approach is that the control hardware is implemented directly in rf without demodulating, compensating, and then remodulating.

  17. Robust control of accelerators

    NASA Astrophysics Data System (ADS)

    Joel, W.; Johnson, D.; Chaouki, Abdallah T.

    1991-07-01

    The problem of controlling the variations in the rf power system can be effectively cast as an application of modern control theory. Two components of this theory are obtaining a model and a feedback structure. The model inaccuracies influence the choice of a particular controller structure. Because of the modelling uncertainty, one has to design either a variable, adaptive controller or a fixed, robust controller to achieve the desired objective. The adaptive control scheme usually results in very complex hardware; and, therefore, shall not be pursued in this research. In contrast, the robust control method leads to simpler hardware. However, robust control requires a more accurate mathematical model of the physical process than is required by adaptive control. Our research at the Los Alamos National Laboratory (LANL) and the University of New Mexico (UNM) has led to the development and implementation of a new robust rf power feedback system. In this article, we report on our research progress. In section 1, the robust control problem for the rf power system and the philosophy adopted for the beginning phase of our research is presented. In section 2, the results of our proof-of-principle experiments are presented. In section 3, we describe the actual controller configuration that is used in LANL FEL physics experiments. The novelty of our approach is that the control hardware is implemented directly in rf. without demodulating, compensating, and then remodulating.

  18. Electron beam manipulation, injection and acceleration in plasma wakefield accelerators by optically generated plasma density spikes

    NASA Astrophysics Data System (ADS)

    Wittig, Georg; Karger, Oliver S.; Knetsch, Alexander; Xi, Yunfeng; Deng, Aihua; Rosenzweig, James B.; Bruhwiler, David L.; Smith, Jonathan; Sheng, Zheng-Ming; Jaroszynski, Dino A.; Manahan, Grace G.; Hidding, Bernhard

    2016-09-01

    We discuss considerations regarding a novel and robust scheme for optically triggered electron bunch generation in plasma wakefield accelerators [1]. In this technique, a transversely propagating focused laser pulse ignites a quasi-stationary plasma column before the arrival of the plasma wake. This localized plasma density enhancement or optical "plasma torch" distorts the blowout during the arrival of the electron drive bunch and modifies the electron trajectories, resulting in controlled injection. By changing the gas density, and the laser pulse parameters such as beam waist and intensity, and by moving the focal point of the laser pulse, the shape of the plasma torch, and therefore the generated trailing beam, can be tuned easily. The proposed method is much more flexible and faster in generating gas density transitions when compared to hydrodynamics-based methods, and it accommodates experimentalists needs as it is a purely optical process and straightforward to implement.

  19. Control of robot dynamics using acceleration control

    NASA Technical Reports Server (NTRS)

    Workman, G. L.; Prateru, S.; Li, W.; Hinman, Elaine

    1992-01-01

    Acceleration control of robotic devices can provide improvements to many space-based operations using flexible manipulators and to ground-based operations requiring better precision and efficiency than current industrial robots can provide. This paper reports on a preliminary study of acceleration measurement on robotic motion during parabolic flights on the NASA KC-135 and a parallel study of accelerations with and without gravity arising from computer simulated motions using TREETOPS software.

  20. Control systems for Coline accelerators

    NASA Astrophysics Data System (ADS)

    Baczewski, Artur; Latała, Agata; Ceglińska, Kaja; Andrasiak, Michał

    2008-01-01

    Medical linear accelerators are the largest group of devices for therapy of cancer diseases because of their compact design, relatively low operating costs, advanced features and broad range of treatment procedures. Their reliability and ease of operation are very important but the most crucial is to ensure personnel and patient safety. For this reason the development of control and safety systems is the current "leading edge" in medical linear accelerators technology. Provided internal monitoring, machine control and steering, interlock system as well as the automatic recording of the device and patient parameters are nowadays fully controlled by the computer. This paper describes in details projects connected to advanced development of Coline accelerators. As it is crucial to assure reliable steering and monitoring of all the machine settings and actual dose delivered to the patient, advanced control systems composed of steering, control and interlock systems, communication protocol as well as data management system have been developed.

  1. A portable accelerator control toolkit

    SciTech Connect

    Watson, W.A. III

    1997-06-01

    In recent years, the expense of creating good control software has led to a number of collaborative efforts among laboratories to share this cost. The EPICS collaboration is a particularly successful example of this trend. More recently another collaborative effort has addressed the need for sophisticated high level software, including model driven accelerator controls. This work builds upon the CDEV (Common DEVice) software framework, which provides a generic abstraction of a control system, and maps that abstraction onto a number of site-specific control systems including EPICS, the SLAC control system, CERN/PS and others. In principle, it is now possible to create portable accelerator control applications which have no knowledge of the underlying and site-specific control system. Applications based on CDEV now provide a growing suite of tools for accelerator operations, including general purpose displays, an on-line accelerator model, beamline steering, machine status displays incorporating both hardware and model information (such as beam positions overlaid with beta functions) and more. A survey of CDEV compatible portable applications will be presented, as well as plans for future development.

  2. Centralized digital control of accelerators

    SciTech Connect

    Melen, R.E.

    1983-09-01

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

  3. Personal computers in accelerator control

    NASA Astrophysics Data System (ADS)

    Anderssen, P. S.

    1988-07-01

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

  4. Injection of electrons by colliding laser pulses in a laser wakefield accelerator

    NASA Astrophysics Data System (ADS)

    Hansson, M.; Aurand, B.; Ekerfelt, H.; Persson, A.; Lundh, O.

    2016-09-01

    To improve the stability and reproducibility of laser wakefield accelerators and to allow for future applications, controlling the injection of electrons is of great importance. This allows us to control the amount of charge in the beams of accelerated electrons and final energy of the electrons. Results are presented from a recent experiment on controlled injection using the scheme of colliding pulses and performed using the Lund multi-terawatt laser. Each laser pulse is split into two parts close to the interaction point. The main pulse is focused on a 2 mm diameter gas jet to drive a nonlinear plasma wave below threshold for self-trapping. The second pulse, containing only a fraction of the total laser energy, is focused to collide with the main pulse in the gas jet under an angle of 150°. Beams of accelerated electrons with low divergence and small energy spread are produced using this set-up. Control over the amount of accelerated charge is achieved by rotating the plane of polarization of the second pulse in relation to the main pulse. Furthermore, the peak energy of the electrons in the beams is controlled by moving the collision point along the optical axis of the main pulse, and thereby changing the acceleration length in the plasma.

  5. Modern control techniques for accelerators

    SciTech Connect

    Goodwin, R.W.; Shea, M.F.

    1984-05-01

    Beginning in the mid to late sixties, most new accelerators were designed to include computer based control systems. Although each installation differed in detail, the technology of the sixties and early to mid seventies dictated an architecture that was essentially the same for the control systems of that era. A mini-computer was connected to the hardware and to a console. Two developments have changed the architecture of modern systems: (a) the microprocessor and (b) local area networks. This paper discusses these two developments and demonstrates their impact on control system design and implementation by way of describing a possible architecture for any size of accelerator. Both hardware and software aspects are included.

  6. Effects of self-focusing on tunnel-ionization-induced injection in a laser wakefield accelerator

    SciTech Connect

    Xia Changquan; Liu Jiansheng; Wang Wentao; Lu Haiyang; Cheng Wang; Deng Aihua; Li Wentao; Zhang Hui; Liang Xiaoyan; Leng Yuxin; Lu Xiaoming; Wang Cheng; Wang Jianzhou; Li Ruxin; Xu Zhizhan; Nakajima, Kazuhisa

    2011-11-15

    We report on the study of the self-focusing effects on the tunnel-ionization-induced injection in a laser wakefield accelerator. Targets composed of a gas mixture of 94% helium and 6% oxygen were used. The energy, energy spread, and charge of the generated electron beams can be adjusted by changing the input laser intensity and the plasma density, but the different aspects of the properties of the electron beams were not independent. It was inferred that the K-shell electrons of oxygen were ionized and injected into the plasma wake for acceleration when the laser intensity was increased beyond the threshold for generating O{sup 7+} by tunnel-ionization, due to the relativistic self-focusing in the propagation. Controlling the self-focusing of the laser beam by adjusting the input laser energy to shorten the distance over which the electrons were injected into the wake, quasi-monoenergetic electron beams were observed.

  7. Control and optimization of a staged laser-wakefield accelerator

    NASA Astrophysics Data System (ADS)

    Golovin, G.; Banerjee, S.; Chen, S.; Powers, N.; Liu, C.; Yan, W.; Zhang, J.; Zhang, P.; Zhao, B.; Umstadter, D.

    2016-09-01

    We report results of an experimental study of laser-wakefield acceleration of electrons, using a staged device based on a double-jet gas target that enables independent injection and acceleration stages. This novel scheme is shown to produce stable, quasi-monoenergetic, and tunable electron beams. We show that optimal accelerator performance is achieved by systematic variation of five critical parameters. For the injection stage, we show that the amount of trapped charge is controlled by the gas density, composition, and laser power. For the acceleration stage, the gas density and the length of the jet are found to determine the final electron energy. This independent control over both the injection and acceleration processes enabled independent control over the charge and energy of the accelerated electron beam while preserving the quasi-monoenergetic character of the beam. We show that the charge and energy can be varied in the ranges of 2-45 pC, and 50-450 MeV, respectively. This robust and versatile electron accelerator will find application in the generation of high-brightness and controllable x-rays, and as the injector stage for more conventional devices.

  8. Electron ripple injection concept for transport control

    SciTech Connect

    Choe, W.; Ono, M.; Hwang, Y.S.

    1992-01-01

    Recent experiments in many devices have provided firm evidence that the edge radial electric field profile differs between L- and H-modes, and that these fields can greatly modify transport in tokamak plasmas. A nonintrusive method for inducing radial electric field based on electron ripple injection is being developed by the CDX-U group. This technique utilizes a pair of special coils to create a local magnetic field ripple to trap the electrons at the edge of the plasma. The trapped electrons then drift into the plasma due to the [del]B drift. An ECH power is applied to accelerate electrons to sufficient perpendicular energy to penetrate into the plasma. Application of ECH power to the trapped electrons should provide the desired 20 A of electron current with electrons of a few keV of energy and v[perpendicular]/v[parallel] [much gt] 1. A controlled experiment to investigate the physics of ECH aided ripple injection has been designed on CDX-U. With the set of ripple coils designed for CDX-U, a ripple fraction of [delta] ([double bond] [del]B/B[sub av]) [approximately] 5% is attainable. At this ripple fraction, electrons are trapped if v[perpendicular]/v[parallel] [much gt] 1> (2[delta])[sup [minus][1/2

  9. Nanoscale Electron Bunching in Laser-Triggered Ionization Injection in Plasma Accelerators.

    PubMed

    Xu, X L; Pai, C-H; Zhang, C J; Li, F; Wan, Y; Wu, Y P; Hua, J F; Lu, W; An, W; Yu, P; Joshi, C; Mori, W B

    2016-07-15

    Ionization injection is attractive as a controllable injection scheme for generating high quality electron beams using plasma-based wakefield acceleration. Because of the phase-dependent tunneling ionization rate and the trapping dynamics within a nonlinear wake, the discrete injection of electrons within the wake is nonlinearly mapped to a discrete final phase space structure of the beam at the location where the electrons are trapped. This phenomenon is theoretically analyzed and examined by three-dimensional particle-in-cell simulations which show that three-dimensional effects limit the wave number of the modulation to between >2k_{0} and about 5k_{0}, where k_{0} is the wave number of the injection laser. Such a nanoscale bunched beam can be diagnosed by and used to generate coherent transition radiation and may find use in generating high-power ultraviolet radiation upon passage through a resonant undulator. PMID:27472116

  10. Nanoscale Electron Bunching in Laser-Triggered Ionization Injection in Plasma Accelerators

    NASA Astrophysics Data System (ADS)

    Xu, X. L.; Pai, C.-H.; Zhang, C. J.; Li, F.; Wan, Y.; Wu, Y. P.; Hua, J. F.; Lu, W.; An, W.; Yu, P.; Joshi, C.; Mori, W. B.

    2016-07-01

    Ionization injection is attractive as a controllable injection scheme for generating high quality electron beams using plasma-based wakefield acceleration. Because of the phase-dependent tunneling ionization rate and the trapping dynamics within a nonlinear wake, the discrete injection of electrons within the wake is nonlinearly mapped to a discrete final phase space structure of the beam at the location where the electrons are trapped. This phenomenon is theoretically analyzed and examined by three-dimensional particle-in-cell simulations which show that three-dimensional effects limit the wave number of the modulation to between >2 k0 and about 5 k0, where k0 is the wave number of the injection laser. Such a nanoscale bunched beam can be diagnosed by and used to generate coherent transition radiation and may find use in generating high-power ultraviolet radiation upon passage through a resonant undulator.

  11. Self-truncated ionization injection and consequent monoenergetic electron bunches in laser wakefield acceleration

    SciTech Connect

    Zeng, Ming; Zhang, Jie; Chen, Min; Department of Mathematics, Institute of Natural Sciences, and MOE-LSC, Shanghai Jiao Tong University, Shanghai 20040 ; Sheng, Zheng-Ming; SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG ; Mori, Warren B.

    2014-03-15

    The ionization-induced injection in laser wakefield acceleration has been recently demonstrated to be a promising injection scheme. However, the energy spread controlling in this mechanism remains a challenge because continuous injection in a mixed gas target is usually inevitable. Here, we propose that by use of certain initially unmatched laser pulses, the electron injection can be constrained to the very front region of the mixed gas target, typically in a length of a few hundreds micrometers determined by the laser self-focusing and the wake deformation. As a result, the produced electron beam has narrow energy spread and meanwhile contains tens of pC in charge. Both multidimensional simulations and theoretical analysis illustrate the effectiveness of this scheme.

  12. Corrosion control in water injection systems

    SciTech Connect

    Patton, C.C. )

    1993-08-01

    Corrosion control in water injection systems encompasses a wide range of technologies, including chemicals (corrosion inhibitors, biocides, and oxygen scavengers); corrosion-resistant materials (metallic and nonmetallic); internal coatings and linings; mechanical removal of dissolved oxygen; velocity control; and prevention of oxygen entry and galvanic couples. This article reviews the way that these technologies are used in modern water-injection systems (both seawater and produced water) to provide an acceptable service life and high-quality injection water.

  13. Beyond injection: Trojan horse underdense photocathode plasma wakefield acceleration

    SciTech Connect

    Hidding, B.; Rosenzweig, J. B.; Xi, Y.; O'Shea, B.; Andonian, G.; Schiller, D.; Barber, S.; Williams, O.; Pretzler, G.; Koenigstein, T.; Kleeschulte, F.; Hogan, M. J.; Litos, M.; Corde, S.; White, W. W.; Muggli, P.; Bruhwiler, D. L.; Lotov, K.

    2012-12-21

    An overview on the underlying principles of the hybrid plasma wakefield acceleration scheme dubbed 'Trojan Horse' acceleration is given. The concept is based on laser-controlled release of electrons directly into a particle-beam-driven plasma blowout, paving the way for controlled, shapeable electron bunches with ultralow emittance and ultrahigh brightness. Combining the virtues of a low-ionization-threshold underdense photocathode with the GV/m-scale electric fields of a practically dephasing-free beam-driven plasma blowout, this constitutes a 4th generation electron acceleration scheme. It is applicable as a beam brightness transformer for electron bunches from LWFA and PWFA systems alike. At FACET, the proof-of-concept experiment 'E-210: Trojan Horse Plasma Wakefield Acceleration' has recently been approved and is in preparation. At the same time, various LWFA facilities are currently considered to host experiments aiming at stabilizing and boosting the electron bunch output quality via a trojan horse afterburner stage. Since normalized emittance and brightness can be improved by many orders of magnitude, the scheme is an ideal candidate for light sources such as free-electron-lasers and those based on Thomson scattering and betatron radiation alike.

  14. Beyond injection: Trojan horse underdense photocathode plasma wakefield acceleration

    NASA Astrophysics Data System (ADS)

    Hidding, B.; Rosenzweig, J. B.; Xi, Y.; O'Shea, B.; Andonian, G.; Schiller, D.; Barber, S.; Williams, O.; Pretzler, G.; Königstein, T.; Kleeschulte, F.; Hogan, M. J.; Litos, M.; Corde, S.; White, W. W.; Muggli, P.; Bruhwiler, D. L.; Lotov, K.

    2012-12-01

    An overview on the underlying principles of the hybrid plasma wakefield acceleration scheme dubbed "Trojan Horse" acceleration is given. The concept is based on laser-controlled release of electrons directly into a particle-beam-driven plasma blowout, paving the way for controlled, shapeable electron bunches with ultralow emittance and ultrahigh brightness. Combining the virtues of a low-ionization-threshold underdense photocathode with the GV/m-scale electric fields of a practically dephasing-free beam-driven plasma blowout, this constitutes a 4th generation electron acceleration scheme. It is applicable as a beam brightness transformer for electron bunches from LWFA and PWFA systems alike. At FACET, the proof-of-concept experiment "E-210: Trojan Horse Plasma Wakefield Acceleration" has recently been approved and is in preparation. At the same time, various LWFA facilities are currently considered to host experiments aiming at stabilizing and boosting the electron bunch output quality via a trojan horse afterburner stage. Since normalized emittance and brightness can be improved by many orders of magnitude, the scheme is an ideal candidate for light sources such as free-electron-lasers and those based on Thomson scattering and betatron radiation alike.

  15. Trends in accelerator control systems

    SciTech Connect

    Crowley-Milling, M.C.

    1984-04-01

    Over the years, we have seen a revolution in control systems that has followed the ever decreasing cost of computer power and memory. It started with the data gathering, when people distrusted the computer to perform control actions correctly, through the stage of using a computer to perform control actions correctly, through the stage of using a computer system to provide a convenient remote look and adjust facility, to the present day, when more and more emphasis is being placed on using a computer system to simulate or model all or parts of the accelerator, feed in the required performance and calling for the computers to set the various parameters and then measure the actual performance, with iteration if necessary. The progress that has been made in the fields of architecture, communications, computers, interface, software design and operator interface is reviewed.

  16. Resonantly Enhanced Betatron Hard X-rays from Ionization Injected Electrons in a Laser Plasma Accelerator

    PubMed Central

    Huang, K.; Li, Y. F.; Li, D. Z.; Chen, L. M.; Tao, M. Z.; Ma, Y.; Zhao, J. R.; Li, M. H.; Chen, M.; Mirzaie, M.; Hafz, N.; Sokollik, T.; Sheng, Z. M.; Zhang, J.

    2016-01-01

    Ultrafast betatron x-ray emission from electron oscillations in laser wakefield acceleration (LWFA) has been widely investigated as a promising source. Betatron x-rays are usually produced via self-injected electron beams, which are not controllable and are not optimized for x-ray yields. Here, we present a new method for bright hard x-ray emission via ionization injection from the K-shell electrons of nitrogen into the accelerating bucket. A total photon yield of 8 × 108/shot and 108 photons with energy greater than 110 keV is obtained. The yield is 10 times higher than that achieved with self-injection mode in helium under similar laser parameters. The simulation suggests that ionization-injected electrons are quickly accelerated to the driving laser region and are subsequently driven into betatron resonance. The present scheme enables the single-stage betatron radiation from LWFA to be extended to bright γ-ray radiation, which is beyond the capability of 3rd generation synchrotrons. PMID:27273170

  17. Resonantly Enhanced Betatron Hard X-rays from Ionization Injected Electrons in a Laser Plasma Accelerator.

    PubMed

    Huang, K; Li, Y F; Li, D Z; Chen, L M; Tao, M Z; Ma, Y; Zhao, J R; Li, M H; Chen, M; Mirzaie, M; Hafz, N; Sokollik, T; Sheng, Z M; Zhang, J

    2016-01-01

    Ultrafast betatron x-ray emission from electron oscillations in laser wakefield acceleration (LWFA) has been widely investigated as a promising source. Betatron x-rays are usually produced via self-injected electron beams, which are not controllable and are not optimized for x-ray yields. Here, we present a new method for bright hard x-ray emission via ionization injection from the K-shell electrons of nitrogen into the accelerating bucket. A total photon yield of 8 × 10(8)/shot and 10(8 )photons with energy greater than 110 keV is obtained. The yield is 10 times higher than that achieved with self-injection mode in helium under similar laser parameters. The simulation suggests that ionization-injected electrons are quickly accelerated to the driving laser region and are subsequently driven into betatron resonance. The present scheme enables the single-stage betatron radiation from LWFA to be extended to bright γ-ray radiation, which is beyond the capability of 3(rd) generation synchrotrons. PMID:27273170

  18. Resonantly Enhanced Betatron Hard X-rays from Ionization Injected Electrons in a Laser Plasma Accelerator

    NASA Astrophysics Data System (ADS)

    Huang, K.; Li, Y. F.; Li, D. Z.; Chen, L. M.; Tao, M. Z.; Ma, Y.; Zhao, J. R.; Li, M. H.; Chen, M.; Mirzaie, M.; Hafz, N.; Sokollik, T.; Sheng, Z. M.; Zhang, J.

    2016-06-01

    Ultrafast betatron x-ray emission from electron oscillations in laser wakefield acceleration (LWFA) has been widely investigated as a promising source. Betatron x-rays are usually produced via self-injected electron beams, which are not controllable and are not optimized for x-ray yields. Here, we present a new method for bright hard x-ray emission via ionization injection from the K-shell electrons of nitrogen into the accelerating bucket. A total photon yield of 8 × 108/shot and 108 photons with energy greater than 110 keV is obtained. The yield is 10 times higher than that achieved with self-injection mode in helium under similar laser parameters. The simulation suggests that ionization-injected electrons are quickly accelerated to the driving laser region and are subsequently driven into betatron resonance. The present scheme enables the single-stage betatron radiation from LWFA to be extended to bright γ-ray radiation, which is beyond the capability of 3rd generation synchrotrons.

  19. Electron ripple injection concept for transport control

    SciTech Connect

    Choe, W.; Ono, M.; Hwang, Y.S.

    1992-10-01

    Recent experiments in many devices have provided firm evidence that the edge radial electric field profile differs between L- and H-modes, and that these fields can greatly modify transport in tokamak plasmas. A nonintrusive method for inducing radial electric field based on electron ripple injection is being developed by the CDX-U group. This technique utilizes a pair of special coils to create a local magnetic field ripple to trap the electrons at the edge of the plasma. The trapped electrons then drift into the plasma due to the {del}B drift. An ECH power is applied to accelerate electrons to sufficient perpendicular energy to penetrate into the plasma. Application of ECH power to the trapped electrons should provide the desired 20 A of electron current with electrons of a few keV of energy and v{perpendicular}/v{parallel} {much_gt} 1. A controlled experiment to investigate the physics of ECH aided ripple injection has been designed on CDX-U. With the set of ripple coils designed for CDX-U, a ripple fraction of {delta} ({double_bond} {del}B/B{sub av}) {approximately} 5% is attainable. At this ripple fraction, electrons are trapped if v{perpendicular}/v{parallel} {much_gt} 1> (2{delta}){sup {minus}{1/2}} {approx}3. A resonant cavity box was fabricated for efficient heating of the trapped electrons. It is also capable of measuring the effect of the field ripple in conjunction with trapped electrons. Some preliminary results are given.

  20. Wakefield-induced ionization injection in beam-driven plasma accelerators

    NASA Astrophysics Data System (ADS)

    Martinez de la Ossa, A.; Mehrling, T. J.; Schaper, L.; Streeter, M. J. V.; Osterhoff, J.

    2015-09-01

    We present a detailed analysis of the features and capabilities of Wakefield-Induced Ionization (WII) injection in the blowout regime of beam driven plasma accelerators. This mechanism exploits the electric wakefields to ionize electrons from a dopant gas and trap them in a well-defined region of the accelerating and focusing wake phase, leading to the formation of high-quality witness-bunches [Martinez de la Ossa et al., Phys. Rev. Lett. 111, 245003 (2013)]. The electron-beam drivers must feature high-peak currents ( Ib 0 ≳ 8.5 kA ) and a duration comparable to the plasma wavelength to excite plasma waves in the blowout regime and enable WII injection. In this regime, the disparity of the magnitude of the electric field in the driver region and the electric field in the rear of the ion cavity allows for the selective ionization and subsequent trapping from a narrow phase interval. The witness bunches generated in this manner feature a short duration and small values of the normalized transverse emittance ( k p σ z ˜ k p ɛ n ˜ 0.1 ). In addition, we show that the amount of injected charge can be adjusted by tuning the concentration of the dopant gas species, which allows for controlled beam loading and leads to a reduction of the total energy spread of the witness beams. Electron bunches, produced in this way, fulfil the requirements to drive blowout regime plasma wakes at a higher density and to trigger WII injection in a second stage. This suggests a promising new concept of self-similar staging of WII injection in steps with increasing plasma density, giving rise to the potential of producing electron beams with unprecedented energy and brilliance from plasma-wakefield accelerators.

  1. Trapping and Acceleration of Nonideal Injected Electron Bunches in Channel-Guided LWFAs

    SciTech Connect

    Hubbard, R.F.; Gordon, D.F.; Jones, T.G.; Sprangle, P.; Ting, A.; Cooley, J.H.; Hafizi, B.; Zigler, A.; Kaganovich, D.

    2004-12-07

    The standard regime for the laser wakefield accelerator (LWFA) usually requires external injection of MeV electrons. Ideally, the injected electron bunch should be injected into the proper phase of the accelerating wake, have a bunch length that is small compared with the plasma wavelength, and a low emittance and energy spread. This paper reports Hamiltonian analysis and simulation studies of two 'nonideal' injection schemes that demonstrate strong phase bunching and good accelerated beam quality in a channel-guided laser wakefield accelerator. For the case of monoenergetic, unphased (long bunch) injection, there is an optimum range of injection energies for which the LWFA can trap a significant fraction of the injected pulse while producing an ultrashort, high-quality accelerated pulse. Phased and unphased injection in a channel-guided LWFA with a broad injected energy spread has also been simulated. Although the trapping fraction is generally much smaller than in the monoenergetic case, some simulations exhibit final accelerated bunches with remarkably small energy spread. These results suggest that relatively poor quality injection pulses may still be useful in LWFA demonstration experiments. Implications for planned LWFA experiments at NRL are discussed.

  2. Observation of longitudinal and transverse self-injections in laser-plasma accelerators.

    PubMed

    Corde, S; Thaury, C; Lifschitz, A; Lambert, G; Ta Phuoc, K; Davoine, X; Lehe, R; Douillet, D; Rousse, A; Malka, V

    2013-01-01

    Laser-plasma accelerators can produce high-quality electron beams, up to giga electronvolts in energy, from a centimetre scale device. The properties of the electron beams and the accelerator stability are largely determined by the injection stage of electrons into the accelerator. The simplest mechanism of injection is self-injection, in which the wakefield is strong enough to trap cold plasma electrons into the laser wake. The main drawback of this method is its lack of shot-to-shot stability. Here we present experimental and numerical results that demonstrate the existence of two different self-injection mechanisms. Transverse self-injection is shown to lead to low stability and poor-quality electron beams, because of a strong dependence on the intensity profile of the laser pulse. In contrast, longitudinal injection, which is unambiguously observed for the first time, is shown to lead to much more stable acceleration and higher-quality electron beams. PMID:23422669

  3. Observation of longitudinal and transverse self-injections in laser-plasma accelerators

    NASA Astrophysics Data System (ADS)

    Corde, S.; Thaury, C.; Lifschitz, A.; Lambert, G.; Ta Phuoc, K.; Davoine, X.; Lehe, R.; Douillet, D.; Rousse, A.; Malka, V.

    2013-02-01

    Laser-plasma accelerators can produce high-quality electron beams, up to giga electronvolts in energy, from a centimetre scale device. The properties of the electron beams and the accelerator stability are largely determined by the injection stage of electrons into the accelerator. The simplest mechanism of injection is self-injection, in which the wakefield is strong enough to trap cold plasma electrons into the laser wake. The main drawback of this method is its lack of shot-to-shot stability. Here we present experimental and numerical results that demonstrate the existence of two different self-injection mechanisms. Transverse self-injection is shown to lead to low stability and poor-quality electron beams, because of a strong dependence on the intensity profile of the laser pulse. In contrast, longitudinal injection, which is unambiguously observed for the first time, is shown to lead to much more stable acceleration and higher-quality electron beams.

  4. Impulsive Injection for Compressor Stator Separation Control

    NASA Technical Reports Server (NTRS)

    Culley, Dennis E.; Braunscheidel, Edward P.; Bright, Michelle M.

    2005-01-01

    Flow control using impulsive injection from the suction surface of a stator vane has been applied in a low speed axial compressor. Impulsive injection is shown to significantly reduce separation relative to steady injection for vanes that were induced to separate by an increase in vane stagger angle of 4 degrees. Injected flow was applied to the airfoil suction surface using spanwise slots pitched in the streamwise direction. Injection was limited to the near-hub region, from 10 to 36 percent of span, to affect the dominant loss due to hub leakage flow. Actuation was provided externally using high-speed solenoid valves closely coupled to the vane tip. Variations in injected mass, frequency, and duty cycle are explored. The local corrected total pressure loss across the vane at the lower span region was reduced by over 20 percent. Additionally, low momentum fluid migrating from the hub region toward the tip was effectively suppressed resulting in an overall benefit which reduced corrected area averaged loss through the passage by 4 percent. The injection mass fraction used for impulsive actuation was typically less than 0.1 percent of the compressor through flow.

  5. Mould temperature control during injection moulding process

    NASA Astrophysics Data System (ADS)

    Postawa, Przemyslaw; Stachowiak, Tomasz

    2015-05-01

    Mould temperature is one of the most important parameter in injection moulding process of thermoplastic polymers in particular semi crystalline polymers. There are a lots of methods of control mould temperature but it is not simple and easy to measure heat transfer precisely. Injection moulds have usually a large mass and this is equal also to large heat capacity of tools and its thermal inertia. Measuring temperature by using contact equipment causes a lot of mistakes, because that method is based on heat transfer between thermocouple and measured area of mould. Result of research of 3 different method of temperature control of mould surface were present in the publication. For this purpose a special experimental mould was made. Mould has eight independent cooling circuits which were connected to the thermo controller Wittmann with two circuits. The main aim of research was to determine the effect of normal process of injection moulding on temperature changing in different area of mould. Under the cavity 4 thermocouple were placed and connect to the recorder what gave a possibility of uploading data during injection process. For that research mould temperature was change in many different layouts. Data and sequences of changes in temperature collected during tests gave very interesting result for discussion. Furthermore use of differences in temperature profile of the mould causes different temperature profile recorded during injection moulding. Tests were made by using fallowing equipment: Krauss Maffei injection moulding machine KM65-C4 and thermo controller Wittmann TPplus2, Shini Rotameter, infrared camera TESTO-890 and thermocouple signal recorder with 4 thermocouples of diameter 1mm located in injection mould 3mm under cavity surface. Draft of experimental mould and thermocouple location were presented in the article, and results of research as a drafts and charts of temperature changing in different area of mould were included.

  6. Injectable controlled release depots for large molecules

    PubMed Central

    Schwendeman, Steven P.; Shah, Ronak B.; Bailey, Brittany A.; Schwendeman, Anna S.

    2014-01-01

    Biodegradable, injectable depot formulations for long-term controlled drug release have improved therapy for a number of drug molecules and led to over a dozen highly successful pharmaceutical products. Until now, success has been limited to several small molecules and peptides, although remarkable improvements have been accomplished in some of these cases. For example, twice-a-year depot injections with leuprolide are available compared to the once-a-day injection of the solution dosage form. Injectable depots are typically prepared by encapsulation of the drug in poly(lactic-co-glycolic acid) (PLGA), a polymer that is used in children every day as a resorbable suture material, and therefore, highly biocompatible. PLGAs remain today as one of the few “real world” biodegradable synthetic biomaterials used in US FDA-approved parenteral long-acting-release (LAR) products. Despite their success, there remain critical barriers to the more widespread use of PLGA LAR products, particularly for delivery of more peptides and other large molecular drugs, namely proteins. In this review, we describe key concepts in the development of injectable PLGA controlled-release depots for peptides and proteins, and then use this information to identify key issues impeding greater widespread use of PLGA depots for this class of drugs. Finally, we examine important approaches, particularly those developed in our research laboratory, toward overcoming these barriers to advance commercial LAR development. PMID:24929039

  7. Combustion oscillation control by cyclic fuel injection

    SciTech Connect

    Richards, G.A.; Yip, M.J.; Robey, E.; Cowell, L.; Rawlins, D.

    1997-04-01

    A number of recent articles have demonstrated the use of active control to mitigate the effects of combustion instability in afterburner and dump combustor applications. In these applications, cyclic injection of small quantities of control fuel has been proposed to counteract the periodic heat release that contributes to undesired pressure oscillations. This same technique may also be useful to mitigate oscillations in gas turbine combustors, especially in test rig combustors characterized by acoustic modes that do not exist in the final engine configuration. To address this issue, the present paper reports on active control of a subscale, atmospheric pressure nozzle.combustor arrangement. The fuel is natural gas. Cyclic injection of 14 percent control fuel in a premix fuel nozzle is shown to reduce oscillating pressure amplitude by a factor of 0.30 (i.e., {minus}10 dB) at 300 Hz. Measurement of the oscillating heat release is also reported.

  8. Combustion oscillation control by cyclic fuel injection

    SciTech Connect

    Richards, G.A.; Yip, M.J.; Robey, E.; Cowell, L.; Rawlins, D.

    1995-04-01

    A number of recent articles have demonstrated the use of active control to mitigate the effects of combustion instability in afterburner and dump combustor applications. In these applications, cyclic injection of small quantities of control fuel has been proposed to counteract the periodic heat release that contributes to undesired pressure oscillations. This same technique may also be useful to mitigate oscillations in gas turbine combustors, especially in test rig combustors characterized by acoustic modes that do not exist in the final engine configuration. To address this issue, the present paper reports on active control of a subscale, atmospheric pressure nozzle/combustor arrangement. The fuel is natural gas. Cyclic injection of 14% control fuel in a premix fuel nozzle is shown to reduce oscillating pressure amplitude by a factor of 0.30 (i.e., {approximately}10 dB) at 300 Hz. Measurement of the oscillating heat release is also reported.

  9. Characterization of electron self-injection in laser wake field acceleration due to the parametric resonance

    SciTech Connect

    Zhidkov, A.; Koga, J.; Hosokai, T.; Kodama, R.; Fujii, T.; Oishi, Y.; Nemoto, K.

    2010-08-15

    The wave-breaking processes originating from a parametric resonance in the wake of a laser pulse in the absence of pulse overfocusing are thoroughly analyzed via multidimensional particle-in-cell simulations. The processes play a key role in the electron self-injection in the laser-driven acceleration of high energy, monoenergetic electrons in plasma channels. The resonance character of the charge loading in the first, second, and third injections is shown; its effect on the electron acceleration is demonstrated.

  10. Passive injection control for microfluidic systems

    DOEpatents

    Paul, Phillip H.; Arnold, Don W.; Neyer, David W.

    2004-12-21

    Apparatus for eliminating siphoning, "dead" regions, and fluid concentration gradients in microscale analytical devices. In its most basic embodiment, the present invention affords passive injection control for both electric field-driven and pressure-driven systems by providing additional fluid flow channels or auxiliary channels disposed on either side of a sample separation column. The auxiliary channels are sized such that volumetric fluid flow rate through these channels, while sufficient to move the sample away from the sample injection region in a timely fashion, is less than that through the sample separation channel or chromatograph.

  11. Electron self-injection in the proton-driven-plasma-wakefield acceleration

    SciTech Connect

    Hu, Zhang-Hu; Wang, You-Nian

    2013-12-15

    The self-injection process of plasma electrons in the proton-driven-plasma-wakefield acceleration scheme is investigated using a two-dimensional, electromagnetic particle-in-cell method. Plasma electrons are self-injected into the back of the first acceleration bucket during the initial bubble formation period, where the wake phase velocity is low enough to trap sufficient electrons. Most of the self-injected electrons are initially located within a distance of the skin depth c/ω{sub pe} to the beam axis. A decrease (or increase) in the beam radius (or length) leads to a significant reduction in the total charges of self-injected electron bunch. Compared to the uniform plasma, the energy spread, emittance and total charges of the self-injected bunch are reduced in the plasma channel case, due to a reduced injection of plasma electrons that initially located further away from the beam axis.

  12. Colliding ionization injection in a plasma wakefield accelerator

    NASA Astrophysics Data System (ADS)

    Wan, Y.; Zhang, C. J.; Li, F.; Wu, Y. P.; Hua, J. F.; Pai, C.-H.; Lu, W.; Gu, Y. Q.; Xu, X. L.; Joshi, C.; Mori, W. B.

    2016-03-01

    A new scheme of generating high quality electron bunches via ionization injection triggered by an counter propagating laser pulse inside a beam driven plasma wake is proposed and examined via two-dimensional particle-in-cell (PIC) simulations. This scheme has two major advantages: first, the injection distance is easily tunable by varying the launching time or the focal position of the laser pulse; second, the electrons in each injected slice are released at nearly the same time. Both factors can significantly reduce the phase space mixing during the ionization injection process (Xu et al 2014 Phys. Rev. Lett. 112 035003, Xu et al 2014 Phys. Rev. Spec. Top.: Accel. Beams 17 061301, Li et al 2013 Phys. Rev. Lett. 111 015003), leading to very small energy spreads (˜10 keV for slice,˜100 keV for the whole bunch) and very small normalized emittance (˜few nm). As an example, a 4.5 fs 0.4 pC electron bunch with normalized emittance of 3.3 nm, slice energy spread of 13 keV, absolute energy spread of 80 keV, and a brightness of 7.2× {{10}18} A m-2rad-2 is obtained under realistic conditions. This scheme may have potential applications for future compact coherent light sources.

  13. Control problems in very large accelerators

    SciTech Connect

    Crowley-Milling, M.C.

    1985-04-01

    There is no fundamental difference of kind in the control requirements between a small and a large accelerator since they are built of the same types of components, which individually have the same types of control inputs and outputs. The main difference is one of scale; the large machine has many more components of each type, and the distances involved are much greater. It is the purpose of this paper to look at the special control problems of large accelerators, which the author shall arbitrarily define as those with a length or circumference in excess of 10 km, and point out where special developments, or the adoption of developments from outside the accelerator control field, can be of assistance in minimizing the cost of the control system.

  14. Controlled electron injection into laser wakefields with a perpendicular injection laser pulse

    SciTech Connect

    Wang, W.-M.; Sheng, Z.-M.; Zhang, J.

    2008-11-17

    Electron injection into laser wakefields for acceleration by two orthogonally directed laser pulses is investigated theoretically. It is found that efficient injection occurs provided the two pulses are collinearly polarized, even if the injection pulse is much weaker than the pump pulse driving wakefields. Compared with the head-on colliding injection geometry, this scheme allows for a shorter propagation distance less than a Rayleigh length for the injection pulse, before its overlapping with the pump pulse. Moreover, it can generate electron beams stably with comparable low energy spread and emittance, as demonstrated by particle-in-cell simulations. The optimization of laser parameters is also investigated.

  15. Control problems in very large accelerators

    SciTech Connect

    Crowley-Milling, M.C.

    1985-06-01

    There is no fundamental difference of kind in the control requirements between a small and a large accelerator since they are built of the same types of components, which individually have similar control inputs and outputs. The main difference is one of scale; the large machine has many more components of each type, and the distances involved are much greater. Both of these factors must be taken into account in determining the optimum way of carrying out the control functions. Small machines should use standard equipment and software for control as much as possible, as special developments for small quantities cannot normally be justified if all costs are taken into account. On the other hand, the very great number of devices needed for a large machine means that, if special developments can result in simplification, they may make possible an appreciable reduction in the control equipment costs. It is the purpose of this report to look at the special control problems of large accelerators, which the author shall arbitarily define as those with a length of circumference in excess of 10 km, and point out where special developments, or the adoption of developments from outside the accelerator control field, can be of assistance in minimizing the cost of the control system. Most of the first part of this report was presented as a paper to the 1985 Particle Accelerator Conference. It has now been extended to include a discussion on the special case of the controls for the SSC.

  16. Application accelerator system having bunch control

    DOEpatents

    Wang, D.; Krafft, G.A.

    1999-06-22

    An application accelerator system for monitoring the gain of a free electron laser is disclosed. Coherent Synchrotron Radiation (CSR) detection techniques are used with a bunch length monitor for ultra short, picosec to several tens of femtosec, electron bunches. The monitor employs an application accelerator, a coherent radiation production device, an optical or beam chopping device, an infrared radiation collection device, a narrow-banding filter, an infrared detection device, and a control. 1 fig.

  17. Application accelerator system having bunch control

    DOEpatents

    Wang, Dunxiong; Krafft, Geoffrey Arthur

    1999-01-01

    An application accelerator system for monitoring the gain of a free electron laser. Coherent Synchrotron Radiation (CSR) detection techniques are used with a bunch length monitor for ultra short, picosec to several tens of femtosec, electron bunches. The monitor employs an application accelerator, a coherent radiation production device, an optical or beam chopping device, an infrared radiation collection device, a narrow-banding filter, an infrared detection device, and a control.

  18. A New Control Room for SLAC Accelerators

    SciTech Connect

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

    2012-06-04

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

  19. An Accelerator Control Middle Layer Using MATLAB

    SciTech Connect

    Portmann, Gregory J.; Corbett, Jeff; Terebilo, Andrei

    2005-03-15

    Matlab is a matrix manipulation language originally developed to be a convenient language for using the LINPACK and EISPACK libraries. What makes Matlab so appealing for accelerator physics is the combination of a matrix oriented programming language, an active workspace for system variables, powerful graphics capability, built-in math libraries, and platform independence. A number of software toolboxes for accelerators have been written in Matlab--the Accelerator Toolbox (AT) for machine simulations, LOCO for accelerator calibration, Matlab Channel Access Toolbox (MCA) for EPICS connections, and the Middle Layer. This paper will describe the ''middle layer'' software toolbox that resides between the high-level control applications and the low-level accelerator control system. This software was a collaborative effort between ALS (LBNL) and SPEAR3 (SSRL) but easily ports to other machines. Five accelerators presently use this software. The high-level Middle Layer functionality includes energy ramp, configuration control (save/restore), global orbit correction, local photon beam steering, insertion device compensation, beam-based alignment, tune correction, response matrix measurement, and script-based programs for machine physics studies.

  20. Phase-space dynamics of ionization injection in plasma-based accelerators.

    PubMed

    Xu, X L; Hua, J F; Li, F; Zhang, C J; Yan, L X; Du, Y C; Huang, W H; Chen, H B; Tang, C X; Lu, W; Yu, P; An, W; Joshi, C; Mori, W B

    2014-01-24

    The evolution of beam phase space in ionization injection into plasma wakefields is studied using theory and particle-in-cell simulations. The injection process involves both longitudinal and transverse phase mixing, leading initially to a rapid emittance growth followed by oscillation, decay, and a slow growth to saturation. An analytic theory for this evolution is presented and verified through particle-in-cell simulations. This theory includes the effects of injection distance (time), acceleration distance, wakefield structure, and nonlinear space charge forces, and it also shows how ultralow emittance beams can be produced using ionization injection methods. PMID:24484147

  1. Electron Injection in Laser Plasma Accelerators by High-Order Field Ionization

    SciTech Connect

    Chen, M.; Esarey, E.; Geddes, C. G. R.; Schroeder, C. B.; Leemans, W. P.

    2010-11-04

    Electron injection and trapping in a laser wakefield accelerator by high-order field ionization is studied theoretically and by particle-in-cell simulations. To obtain low energy spread beams we use a short region of gas mixture (H+N) near the start of the stage to trap electrons, while the remainder of the stage uses pure H and is injection-free. Effects of gas mix parameters, such as concentration and length, on the final electron injection number and beam quality are studied. Laser polarization and shape effects on injection number and final electron emittance are also shown.

  2. The BNL Accelerator Test Facility control system

    SciTech Connect

    Malone, R.; Bottke, I.; Fernow, R.; Ben-Zvi, I.

    1993-01-01

    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.

  3. Tanshinon IIA Injection Accelerates Tissue Expansion by Reducing the Formation of the Fibrous Capsule

    PubMed Central

    Yang, Mei; Zhu, Ming; Huang, Xiaolu; Li, Qingfeng

    2014-01-01

    The tissue expansion technique has been applied to obtain new skin tissue to repair large defects in clinical practice. The implantation of tissue expander could initiate a host response to foreign body (FBR), which leads to fibrotic encapsulation around the expander and prolongs the period of tissue expansion. Tanshinon IIA (Tan IIA) has been shown to have anti-inflammation and immunoregulation effect. The rat tissue expansion model was used in this study to observe whether Tan IIA injection systematically could inhibit the FBR to reduce fibrous capsule formation and accelerate the process of tissue expansion. Forty-eight rats were randomly divided into the Tan IIA group and control group with 24 rats in each group. The expansion was conducted twice a week to maintain a capsule pressure of 60 mmHg. The expansion volume and expanded area were measured. The expanded tissue in the two groups was harvested, and histological staining was performed; proinflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β) and transforming growth factor-β (TGF-β) were examined. The expansion volume and the expanded area in the Tan IIA group were greater than that of the control group. The thickness of the fibrous capsule in the Tan IIA group was reduced with no influence on the normal skin regeneration. Decreased infiltration of macrophages, lower level of TNF-α, IL-6, IL-1β and TGF-β, less proliferating myofibroblasts and enhanced neovascularization were observed in the Tan IIA group. Our findings indicated that the Tan IIA injection reduced the formation of the fibrous capsule and accelerated the process of tissue expansion by inhibiting the FBR. PMID:25157742

  4. Fermilab accelerator control system: Analog monitoring facilities

    SciTech Connect

    Seino, K.; Anderson, L.; Smedinghoff, J.

    1987-10-01

    Thousands of analog signals are monitored in different areas of the Fermilab accelerator complex. For general purposes, analog signals are sent over coaxial or twinaxial cables with varying lengths, collected at fan-in boxes and digitized with 12 bit multiplexed ADCs. For higher resolution requirements, analog signals are digitized at sources and are serially sent to the control system. This paper surveys ADC subsystems that are used with the accelerator control systems and discusses practical problems and solutions, and it describes how analog data are presented on the console system.

  5. Dynamics of ionization-induced electron injection in the high density regime of laser wakefield acceleration

    SciTech Connect

    Desforges, F. G.; Paradkar, B. S. Ju, J.; Audet, T. L.; Maynard, G.; Cros, B.; Hansson, M.; Senje, L.; Persson, A.; Lundh, O.; Wahlström, C.-G.; Dobosz-Dufrénoy, S.; Monot, P.; Vay, J.-L.

    2014-12-15

    The dynamics of ionization-induced electron injection in high density (∼1.2 × 10{sup 19} cm{sup −3}) regime of laser wakefield acceleration is investigated by analyzing the betatron X-ray emission. In such high density operation, the laser normalized vector potential exceeds the injection-thresholds of both ionization-injection and self-injection due to self-focusing. In this regime, direct experimental evidence of early on-set of ionization-induced injection into the plasma wave is given by mapping the X-ray emission zone inside the plasma. Particle-In-Cell simulations show that this early on-set of ionization-induced injection, due to its lower trapping threshold, suppresses the trapping of self-injected electrons. A comparative study of the electron and X-ray properties is performed for both self-injection and ionization-induced injection. An increase of X-ray fluence by at least a factor of two is observed in the case of ionization-induced injection due to increased trapped charge compared to self-injection mechanism.

  6. Dynamic Feed Control For Injection Molding

    DOEpatents

    Kazmer, David O.

    1996-09-17

    The invention provides methods and apparatus in which mold material flows through a gate into a mold cavity that defines the shape of a desired part. An adjustable valve is provided that is operable to change dynamically the effective size of the gate to control the flow of mold material through the gate. The valve is adjustable while the mold material is flowing through the gate into the mold cavity. A sensor is provided for sensing a process condition while the part is being molded. During molding, the valve is adjusted based at least in part on information from the sensor. In the preferred embodiment, the adjustable valve is controlled by a digital computer, which includes circuitry for acquiring data from the sensor, processing circuitry for computing a desired position of the valve based on the data from the sensor and a control data file containing target process conditions, and control circuitry for generating signals to control a valve driver to adjust the position of the valve. More complex embodiments include a plurality of gates, sensors, and controllable valves. Each valve is individually controllable so that process conditions corresponding to each gate can be adjusted independently. This allows for great flexibility in the control of injection molding to produce complex, high-quality parts.

  7. Production of a monoenergetic electron bunch in a self-injected laser-wakefield accelerator.

    PubMed

    Chang, C-L; Hsieh, C-T; Ho, Y-C; Chen, Y-S; Lin, J-Y; Wang, J; Chen, S-Y

    2007-03-01

    Production of a monoenergetic electron bunch in a self-injected laser-wakefield accelerator is investigated with a tomographic method which resolves the electron injection and acceleration processes. It is found that all the electrons in the monoenergetic electron bunch are injected at the same location in the plasma column and then accelerated with an acceleration gradient exceeding 2 GeV/cm. The injection position shifts with the position of pump-pulse focus, and no significant deceleration is observed for the monoenergetic electron bunch after it reaches the maximum energy. The results are consistent with the model of transverse wave breaking and beam loading for the injection of monoenergetic electrons. The tomographic method adds a crucial dimension to the whole array of existing diagnostics for laser beams, plasma waves, and electron beams. With this method the details of the underlying physical processes in laser-plasma interactions can be resolved and compared directly to particle-in-cell simulations. PMID:17500801

  8. Near-threshold electron injection in the laser-plasma wakefield accelerator leading to femtosecond bunches

    NASA Astrophysics Data System (ADS)

    Islam, M. R.; Brunetti, E.; Shanks, R. P.; Ersfeld, B.; Issac, R. C.; Cipiccia, S.; Anania, M. P.; Welsh, G. H.; Wiggins, S. M.; Noble, A.; Cairns, R. A.; Raj, G.; Jaroszynski, D. A.

    2015-09-01

    The laser-plasma wakefield accelerator is a compact source of high brightness, ultra-short duration electron bunches. Self-injection occurs when electrons from the background plasma gain sufficient momentum at the back of the bubble-shaped accelerating structure to experience sustained acceleration. The shortest duration and highest brightness electron bunches result from self-injection close to the threshold for injection. Here we show that in this case injection is due to the localized charge density build-up in the sheath crossing region at the rear of the bubble, which has the effect of increasing the accelerating potential to above a critical value. Bunch duration is determined by the dwell time above this critical value, which explains why single or multiple ultra-short electron bunches with little dark current are formed in the first bubble. We confirm experimentally, using coherent optical transition radiation measurements, that single or multiple bunches with femtosecond duration and peak currents of several kiloAmpere, and femtosecond intervals between bunches, emerge from the accelerator.

  9. Functionalized injectable hydrogels for controlled insulin delivery.

    PubMed

    Huynh, Dai P; Nguyen, Minh K; Pi, Bong S; Kim, Min S; Chae, Su Y; Lee, Kang C; Kim, Bong S; Kim, Sung W; Lee, Doo S

    2008-06-01

    The concept of this research is using poly(beta-amino ester) (PAE) as a duo-functional group for synthesis of the novel sensitive injectable hydrogel for controlled drug/protein delivery. Firstly, PAE made of 1,4-butanediol diacrylate and 4,4'-trimethylene dipiperidine is used as a pH-sensitive moiety to conjugate to the temperature-sensitive biodegradable triblock copolymer of poly(ethylene glycol)-poly(epsilon-caprolactone) (PCL-PEG-PCL) to manufacture pH/temperature-sensitive injectable hydrogel of pentablock copolymer PAE-PCL-PEG-PCL-PAE. Furthermore, the cationic nature of PAE is used as the second function to make the ionic complexes with anionic biomolecule loaded into the hydrogel such as insulin. As a result, the release of drug/protein from this hydrogel device can be controlled by the degradation of copolymer. Sol-gel phase transition behavior of PAE-PCL-PEG-PCL-PAE block copolymer was investigated; the results showed that the aqueous media of the pentablock copolymer changed from a sol to a gel phase with increasing temperature and pH. The effect of anionic biomolecule such as insulin on sol-gel phase transition, degradation of the complex gel of the material with insulin was studied in vitro. Then the schematic of the ionic complexes between positive charges in PAE and the negatively charges in protein was simulated. In addition, the mechanism of controlled release behavior of insulin from the complex gel was supposed, which includes the chemically-controlled and diffusion-controlled stages. To prove the simulations, the cumulative release of the protein from the complex gel was investigated in vitro with different methods. Furthermore, the pharmacokinetic release of insulin from the complex gel in vivo on male Sprague-Dawley (SD) rats was compared with that from triblock copolymer hydrogel of PCL-PEG-PCL. PMID:18329707

  10. Ponderomotive acceleration of injected electrons in tenuous plasmas by intense laser pulses

    SciTech Connect

    Sazegari, V.; Shokri, B.

    2006-11-15

    The trapping and acceleration of an electron by forward ponderomotive force associated with intense short laser pulses, propagating in homogeneous rarefied plasmas is analyzed. This is done not by solving the motion equations but by energy conservation law and Lorentz transformation. This method is able to the treat the ponderomotive acceleration regardless of laser polarization. It is shown that the gain of acceleration increases linearly with the field strength of the laser and the relativistic factor of the group velocity of the laser in the plasma, while the minimum injection energy necessary for trapping the electron decreases with the laser field strength and increases slowly with the group velocity of the laser.

  11. An Accelerator Control Middle Layer Using MATLAB

    SciTech Connect

    Portmann, Gregory J.; Corbett, Jeff; Terebilo, Andrei

    2005-05-15

    Matlab is an interpretive programming language originally developed for convenient use with the LINPACK and EISPACK libraries. Matlab is appealing for accelerator physics because it is matrix-oriented, provides an active workspace for system variables, powerful graphics capabilities, built-in math libraries, and platform independence. A number of accelerator software toolboxes have been written in Matlab -- the Accelerator Toolbox (AT) for model-based machine simulations, LOCO for on-line model calibration, and Matlab Channel Access (MCA) to connect with EPICS. The function of the MATLAB ''MiddleLayer'' is to provide a scripting language for machine simulations and on-line control, including non-EPICS based control systems. The MiddleLayer has simplified and streamlined development of high-level applications including configuration control, energy ramp, orbit correction, photon beam steering, ID compensation, beam-based alignment, tune correction and response matrix measurement. The database-driven Middle Layer software is largely machine-independent and easy to port. Six accelerators presently use the software package with more scheduled to come on line soon.

  12. Dual effects of stochastic heating on electron injection in laser wakefield acceleration

    SciTech Connect

    Deng, Z. G.; Wang, X. G.; Yang, L.; Zhou, C. T.; Yu, M. Y.; Ying, H. P.

    2014-08-15

    Electron injection into the wakefield of an intense short laser pulse by a weaker laser pulse propagating in the opposite direction is reconsidered using two-dimensional (2D) particle-in-cell simulations as well as analytical modeling. It is found that for linearly polarized lasers the injection efficiency and the quality of the wakefield accelerated electrons increase with the intensity of the injection laser only up to a certain level, and then decreases. Theory and simulation tracking test electrons originally in the beat region of the two laser pulses show that the reduction of the injection efficiency at high injection-laser intensities is caused by stochastic overheating of the affected electrons.

  13. Role of stochastic heating in wakefield acceleration when optical injection is used

    SciTech Connect

    Rassou, S.; Bourdier, A.; Drouin, M.

    2014-08-15

    The dynamics of an electron in two counterpropagating waves is investigated. Conditions for stochastic acceleration are derived. The possibility of stochastic heating is confirmed when two waves interact with low density plasma by performing PIC (Particle In Cell) code simulations. It is shown that stochastic heating can play an important role in laser wakefield acceleration. When considering low density plasma interacting with a high intensity wave perturbed by a low intensity counterpropagating wave, stochastic heating can provide electrons with the right momentum for trapping in the wakefield. The influence of stochastic acceleration on the trapping of electrons is compared to the one of the beatwave force which is responsible for cold injection. To do so, several polarizations for the colliding pulses are considered. For some value of the plasma density and pulse duration, a transition from an injection due to stochastic acceleration to a cold injection dominated regime—regarding the trapped charge—has been observed from 2D and 3D PIC code simulations. This transition is ruled by the ratio of the interaction length of the pulses to the longitudinal size of the bubble. When the interaction length of the laser pulses reaches the radius of the accelerating cavity stochastic heating becomes dominant, and might be necessary to get electrons trapped into the wakefield, when wakefield inhibition grows with plasma density.

  14. Beam loading by distributed injection of electrons in a plasma wakefield accelerator.

    PubMed

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

    2014-01-17

    We show through experiments and supporting simulations that propagation of a highly relativistic and dense electron bunch through a plasma can lead to distributed injection of electrons, which depletes the accelerating field, i.e., beam loads the wake. The source of the injected electrons is ionization of the second electron of rubidium (Rb II) within the wake. This injection of excess charge is large enough to severely beam load the wake, and thereby reduce the transformer ratio T. The reduction of the average T with increasing beam loading is quantified for the first time by measuring the ratio of peak energy gain and loss of electrons while changing the beam emittance. Simulations show that beam loading by Rb II electrons contributes to the reduction of the peak accelerating field from its weakly loaded value of 43  GV/m to a strongly loaded value of 26  GV/m. PMID:24484020

  15. Self-guided laser wakefield acceleration beyond 1 GeV using ionization-induced injection.

    PubMed

    Clayton, C E; Ralph, J E; Albert, F; Fonseca, R A; Glenzer, S H; Joshi, C; Lu, W; Marsh, K A; Martins, S F; Mori, W B; Pak, A; Tsung, F S; Pollock, B B; Ross, J S; Silva, L O; Froula, D H

    2010-09-01

    The concepts of matched-beam, self-guided laser propagation and ionization-induced injection have been combined to accelerate electrons up to 1.45 GeV energy in a laser wakefield accelerator. From the spatial and spectral content of the laser light exiting the plasma, we infer that the 60 fs, 110 TW laser pulse is guided and excites a wake over the entire 1.3 cm length of the gas cell at densities below 1.5 × 10(18) cm(-3). High-energy electrons are observed only when small (3%) amounts of CO2 gas are added to the He gas. Computer simulations confirm that it is the K-shell electrons of oxygen that are ionized and injected into the wake and accelerated to beyond 1 GeV energy. PMID:20867526

  16. Control system for the NBS microtron accelerator

    NASA Astrophysics Data System (ADS)

    Martin, E. Ray; Trout, Robert E.; Wilson, Bonnie L.; Ayres, Robert L.; Yoder, Neil R.

    1986-06-01

    As various subsystems of the National Bureau of Standards/Los Alamos racetrack microtron accelerator are being brought on-line, experience has been gained with some of the innovations implemented in the control system. Foremost among these are the joystick-based operator controls, the hierarchical distribution of control system intelligence, and the independent secondary stations, permitting sectional stand-alone operation. The result of the distributed database philosophy and parallel data links has been very fast data updates, permitting joystick interaction with system elements. The software development was greatly simplified by using the hardware arbitration of several parallel processors in the Multibus system to split the software tasks into independent modules.

  17. ACCELERATOR TARGET POSITIONER AND CONTROL CIRCUIT THEREFOR

    DOEpatents

    Stone, K.F.; Force, R.J.; Olson, W.W.; Cagle, D.S.

    1959-12-15

    An apparatus is described for inserting and retracting a target material with respect to the internal beam of a charged particle accelerator and to circuitry for controlling the timing and motion of the target placement. Two drive coils are mounted on the shaft of a target holder arm and disposed within the accelerator magnetic field with one coil at right angles to the other. Control circuitry alternately connects each coil to a current source and to a varying shorting resistance whereby the coils interchangeably produce driving and braking forces which swing the target arm within a ninety degree arc. The target is thus moved into the beam and away from it at high speeds and is brought to rest after each movement without whiplash or vibration.

  18. Object oriented programming interfaces for accelerator control

    SciTech Connect

    Hoff, L.T.

    1997-07-01

    Several years ago, the AGS controls group was given the task of developing software for the RHIC accelerator. Like the AGS, the RHIC control system needs to control and monitor equipment distributed around a relatively large geographic area. A local area network connects this equipment to a collection of UNIX workstations in a central control room. Similar software had been developed for the AGS about a decade earlier, but isn`t well suited for RHIC use for a number of reasons. Rather than adapt the AGS software for RHIC use, the controls group opted to start with a clean slate. To develop software that would address the shortcomings of the AGS software, while preserving the useful features that evolved through years of use. A current trend in control system design is to provide an object oriented programming interface for application developers. This talk will discuss important aspects and features of object oriented application programming interfaces (APIs) for accelerator control systems, and explore why such interfaces are becoming the norm.

  19. Particle injection and acceleration at earth's bow shock - Comparison of upstream and downstream events

    NASA Technical Reports Server (NTRS)

    Ellison, Donald C.; Moebius, Eberhard; Paschmann, Goetz

    1990-01-01

    The injection and acceleration of thermal solar wind ions at the quasi-parallel earth's bow shock during radial interplanetary magnetic field conditions is investigated. Active Magnetospheric Particle Tracer Explorers/Ion Release Module satellite observations of complete proton spectra, and of heavy ion spectra above 10 keV/Q, made on September 12, 1984 near the nose of the shock, are presented and compared to the predictions of a Monte Carlo shock simulation which includes diffusive shock acceleration. It is found that the spectral observations are in good agreement with the predictions of the simulation when it is assumed that all accelerated ions originate in the solar wind and are injected into the acceleration mechanism by thermal leakage from the downstream plasma. The efficiency, which is determined directly from the downstream observations, is high, with at least 15 percent of the solar wind energy flux going into accelerated particles. The comparisons allow constraints to be placed on the rigidity dependence of the scattering mean free path and suggest that the upstream solar wind must be slowed substantially by backstreaming accelerated ions prior to undergoing a sharp transition in the viscous subshock.

  20. [Weekly control measurement at the linear accelerator].

    PubMed

    Christ, G

    1983-05-01

    Weekly control measurements taken at the linear accelerator of the Medizinisches Strahleninstitut der Universität Tübingen are described which largely exceed those prescribed by the "Richtlinien Strahlenschutz in der Medizin" (instructions about radioprotection in medicine). Since the determination of the field homogeneity and the energy of electron and X-ray radiation is very time-consuming, a largely automatized procedure has been elaborated which is presented in this study. PMID:6857748

  1. Neural networks and orbit control in accelerators

    SciTech Connect

    Bozoki, E.; Friedman, A.

    1994-07-01

    An overview of the architecture, workings and training of Neural Networks is given. We stress the aspects which are important for the use of Neural Networks for orbit control in accelerators and storage rings, especially its ability to cope with the nonlinear behavior of the orbit response to `kicks` and the slow drift in the orbit response during long-term operation. Results obtained for the two NSLS storage rings with several network architectures and various training methods for each architecture are given.

  2. Accelerator controls at CERN: Some converging trends

    NASA Astrophysics Data System (ADS)

    Kuiper, B.

    1990-08-01

    CERN's growing services to the high-energy physics community using frozen resources has led to the implementation of "Technical Boards", mandated to assist the management by making recommendations for rationalizations in various technological domains. The Board on Process Control and Electronics for Accelerators, TEBOCO, has emphasized four main lines which might yield economy in resources. First, a common architecture for accelerator controls has been agreed between the three accelerator divisions. Second, a common hardware/software kit has been defined, from which the large majority of future process interfacing may be composed. A support service for this kit is an essential part of the plan. Third, high-level protocols have been developed for standardizing access to process devices. They derive from agreed standard models of the devices and involve a standard control message. This should ease application development and mobility of equipment. Fourth, a common software engineering methodology and a commercial package of application development tools have been adopted. Some rationalization in the field of the man-machine interface and in matters of synchronization is also under way.

  3. Linear induction accelerators made from pulse-line cavities with external pulse injection.

    PubMed

    Smith, I

    1979-06-01

    Two types of linear induction accelerator have been reported previously. In one, unidirectional voltage pulses are generated outside the accelerator and injected into the accelerator cavity modules, which contain ferromagnetic material to reduce energy losses in the form of currents induced, in parallel with the beam, in the cavity structure. In the other type, the accelerator cavity modules are themselves pulse-forming lines with energy storage and switches; parallel current losses are made zero by the use of circuits that generate bidirectional acceleration waveforms with a zero voltage-time integral. In a third type of design described here, the cavities are externally driven, and 100% efficient coupling of energy to the beam is obtained by designing the external pulse generators to produce bidirectional voltage waveforms with zero voltage-time integral. A design for such a pulse generator is described that is itself one hundred percent efficient and which is well suited to existing pulse power techniques. Two accelerator cavity designs are described that can couple the pulse from such a generator to the beam; one of these designs provides voltage doubling. Comparison is made between the accelerating gradients that can be obtained with this and the preceding types of induction accelerator. PMID:18699588

  4. Evaluation of Sorbent Injection for Mercury Control

    SciTech Connect

    Sharon Sjostrom

    2005-12-30

    The power industry in the U.S. is faced with meeting new regulations to reduce the emissions of mercury compounds from coal-fired plants. These regulations are directed at the existing fleet of nearly 1,100 boilers. These plants are relatively old with an average age of over 40 years. Although most of these units are capable of operating for many additional years, there is a desire to minimize large capital expenditures because of the reduced (and unknown) remaining life of the plant to amortize the project. Injecting a sorbent such as powdered activated carbon into the flue gas represents one of the simplest and most mature approaches to controlling mercury emissions from coal-fired boilers. This is the final site report for tests conducted at Laramie River Station Unit 3, one of five sites evaluated in this DOE/NETL program. The overall objective of the test program is to evaluate the capabilities of activated carbon injection at five plants: Sunflower Electric's Holcomb Station Unit 1, AmerenUE's Meramec Station Unit 2, Missouri Basin Power Project's Laramie River Station Unit 3, Detroit Edison's Monroe Power Plant Unit 4, and AEP's Conesville Station Unit 6. These plants have configurations that together represent 78% of the existing coal-fired generation plants. The goals for the program established by DOE/NETL are to reduce the uncontrolled mercury emissions by 50 to 70% at a cost 25 to 50% lower than the benchmark established by DOE of $60,000/lb mercury removed. The goals of the program were exceeded at Laramie River Station by achieving over 90% mercury removal at a sorbent cost of $3,980/lb ($660/oz) mercury removed for a coal mercury content of 7.9 lb/TBtu.

  5. Beam optics of the 2 MeV proton injection line at the LLUMC proton accelerator

    NASA Astrophysics Data System (ADS)

    Coutrakon, G.; Hubbard, J.; Sanders, E.

    2005-12-01

    Simulations of the beam optics of the LLUMC proton accelerator injection line have been modeled using the computer codes Parmila [Los Alamos Nat'l Lab, Internal Report LA-UR-98-4478, Los Alamos Accelerator Code Group, Los Alamos, NM] and Trace 3D [Distributed by AccelSoft Inc, P.O. Box 2813. Del Mar, CA 92014, United States]. These simulations give reasonable agreement with the known accelerator dispersion, beam energy spread and optimal debuncher setting. The purpose of this paper is to understand the beam losses and show where improvements can be made, if required, in the future. It has previously been found [G. Coutrakon et al., J. Med. Phys. 20 (11) (1994) 1691] that most intensity losses in the synchrotron can be ascribed to the narrow energy acceptance of the synchrotron. While the present intensity of the accelerator is quite adequate for patient treatments, future plans to treat larger fields will make higher intensity more desirable. A simulation has been performed which adds a second debuncher, or energy compactor, which shows a reduction in energy spread by a factor of two yielding a factor of two increase in the available intensity. The present intensity of 2.5 × 1010 protons per pulse with 34% of the injected intensity captured in the ring can possibly be improved to 5 × 1010 protons per pulse by capturing 68% of the injected beam intensity. These results are discussed in this paper.

  6. LASER WAKEFIELD ACCELERATION BEYOND 1 GeV USING IONIZATION INDUCED INJECTION*

    SciTech Connect

    Marsh, K A; Clayton, C E; Joshi, C; Lu, W; Mori, W B; Pak, A; silva, L O; Lemos, N; Fonseca, R A; de Freitas, S; Albert, F; Doeppner, T; Filip, C; Froula, D; Glenzer, S H; Price, D; Ralph, J; Pollock, B B

    2011-03-22

    A series of laser wake field accelerator experiments leading to electron energy exceeding 1 GeV are described. Theoretical concepts and experimental methods developed while conducting experiments using the 10 TW Ti:Sapphire laser at UCLA were implemented and transferred successfully to the 100 TW Callisto Laser System at the Jupiter Laser Facility at LLNL. To reach electron energies greater than 1 GeV with current laser systems, it is necessary to inject and trap electrons into the wake and to guide the laser for more than 1 cm of plasma. Using the 10 TW laser, the physics of self-guiding and the limitations in regards to pump depletion over cm-scale plasmas were demonstrated. Furthermore, a novel injection mechanism was explored which allows injection by ionization at conditions necessary for generating electron energies greater than a GeV. The 10 TW results were followed by self-guiding at the 100 TW scale over cm plasma lengths. The energy of the self-injected electrons, at 3 x 10{sup 18} cm{sup -3} plasma density, was limited by dephasing to 720 MeV. Implementation of ionization injection allowed extending the acceleration well beyond a centimeter and 1.4 GeV electrons were measured.

  7. Linear accelerator design study with direct plasma injection scheme for warm dense matter

    SciTech Connect

    Kondo, K.; Kanesue, T; Okamura, M.

    2011-03-28

    Warm Dense Matter (WDM) is a challenging science field, which is related to heavy ion inertial fusion and planetary science. It is difficult to expect the behavior because the state with high density and low temperature is completely different from ideal condition. The well-defined WDM generation is required to understand it. Moderate energy ion beams ({approx} MeV/u) slightly above Bragg peak is an advantageous method for WDM because of the uniform energy deposition. Direct Plasma Injection Scheme (DPIS) with a Interdigital H-mode (IH) accelerator has a potential for the beam parameter. We show feasible parameters of the IH accelerator for WDM. WDM physics is a challenging science and is strongly related to Heavy Ion Fusion science. WDM formation by Direct Plasma Injection Scheme (DPIS) with IH accelerator, which is a compact system, is proposed. Feasible parameters for IH accelerator are shown for WDM state. These represents that DPIS with IH accelerator can access a different parameter region of WDM.

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

    SciTech Connect

    Parsa, Z.; Ko, S.K.

    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.

  9. Evaluation of Sorbent Injection for Mercury Control

    SciTech Connect

    Sharon Sjostrom

    2008-06-30

    ADA-ES, Inc., with support from DOE/NETL, EPRI, and industry partners, studied mercury control options at six coal-fired power plants. The overall objective of the this test program was to evaluate the capabilities of activated carbon injection at six plants: Sunflower Electric's Holcomb Station Unit 1, AmerenUE's Meramec Station Unit 2, Missouri Basin Power Project's Laramie River Station Unit 3, Detroit Edison's Monroe Power Plant Unit 4, American Electric Power's Conesville Station Unit 6, and Labadie Power Plant Unit 2. These plants have configurations that together represent 78% of the existing coal-fired generation plants. The financial goals for the program established by DOE/NETL were to reduce the uncontrolled mercury emissions by 50 to 70% at a cost 25 to 50% lower than the target established by DOE of $60,000 per pound of mercury removed. Results from testing at Holcomb, Laramie, Meramec, Labadie, and Monroe indicate the DOE goal was successfully achieved. However, further improvements for plants with conditions similar to Conesville are recommended that would improve both mercury removal performance and economics.

  10. Evaluation of Sorbent Injection for Mercury Control

    SciTech Connect

    Sharon Sjostrom

    2004-10-29

    The power industry in the U.S. is faced with meeting new regulations to reduce the emissions of mercury compounds from coal-fired plants. These regulations are directed at the existing fleet of nearly 1,100 boilers. These plants are relatively old with an average age of over 40 years. Although most of these units are capable of operating for many additional years, there is a desire to minimize large capital expenditures because of the reduced (and unknown) remaining life of the plant to amortize the project. Injecting a sorbent such as powdered activated carbon into the flue gas represents one of the simplest and most mature approaches to controlling mercury emissions from coal-fired boilers. The overall objective of the test program described in this quarterly report is to evaluate the capabilities of activated carbon injection at four plants with configurations that together represent 78% of the existing coal-fired generation plants. This technology was successfully evaluated in NETL's Phase I tests at scales up to 150 MW, on plants burning subbituminous and bituminous coals and with ESPs and fabric filters. The tests also identified issues that still need to be addressed, such as evaluating performance on other configurations, optimizing sorbent usage (costs), and gathering longer-term operating data to address concerns about the impact of activated carbon on plant equipment and operations. The four sites identified for testing are Sunflower Electric's Holcomb Station, AmerenUE's Meramec Station, AEP's Conesville Station, and a site burning a blend of bituminous and subbituminous coals with a cold-side ESP. This is the fourth quarterly report for this project. Long-term testing was completed at Holcomb during this reporting period and baseline testing at Meramec was begun. Preliminary results from long-term testing at Holcomb are included in this report. Planning information for the other three sites is also included. In general, quarterly reports will be used

  11. Evaluation of Sorbent Injection for Mercury Control

    SciTech Connect

    Sharon Sjostrom

    2006-04-30

    The power industry in the U.S. is faced with meeting new regulations to reduce the emissions of mercury compounds from coal-fired plants. These regulations are directed at the existing fleet of nearly 1,100 boilers. These plants are relatively old with an average age of over 40 years. Although most of these units are capable of operating for many additional years, there is a desire to minimize large capital expenditures because of the reduced (and unknown) remaining life of the plant to amortize the project. Injecting a sorbent such as powdered activated carbon into the flue gas represents one of the simplest and most mature approaches to controlling mercury emissions from coal-fired boilers. This is the final site report for tests conducted at DTE Energy's Monroe Power Plant, one of five sites evaluated in this DOE/NETL program. The overall objective of the test program was to evaluate the capabilities of activated carbon injection at five plants: Sunflower Electric's Holcomb Station Unit 1, AmerenUE's Meramec Station Unit 2, Missouri Basin Power Project's Laramie River Station Unit 3, Detroit Edison's Monroe Power Plant Unit 4, and AEP's Conesville Station Unit 6. These plants have configurations that together represent 78% of the existing coal-fired generation plants. The goals for the program established by DOE/NETL were to reduce the uncontrolled mercury emissions by 50 to 70% at a cost 25 to 50% lower than the target established by DOE of $60,000/lb mercury removed. The results from Monroe indicate that using DARCO{reg_sign} Hg would result in higher mercury removal (80%) at a sorbent cost of $18,000/lb mercury, or 70% lower than the benchmark. These results demonstrate that the goals established by DOE/NETL were exceeded during this test program. The increase in mercury removal over baseline conditions is defined for this program as a comparison in the outlet emissions measured using the Ontario Hydro method during the baseline and long-term test periods

  12. Evaluation of Sorbent Injection for Mercury Control

    SciTech Connect

    Sharon Sjostrom

    2005-02-02

    The power industry in the U.S. is faced with meeting new regulations to reduce the emissions of mercury compounds from coal-fired plants. These regulations are directed at the existing fleet of nearly 1,100 boilers. These plants are relatively old with an average age of over 40 years. Although most of these units are capable of operating for many additional years, there is a desire to minimize large capital expenditures because of the reduced (and unknown) remaining life of the plant to amortize the project. Injecting a sorbent such as powdered activated carbon into the flue gas represents one of the simplest and most mature approaches to controlling mercury emissions from coal-fired boilers. The overall objective of the test program described in this quarterly report is to evaluate the capabilities of activated carbon injection at five plants with configurations that together represent 78% of the existing coal-fired generation plants. This technology was successfully evaluated in NETL's Phase I tests at scales up to 150 MW, on plants burning subbituminous and bituminous coals and with ESPs and fabric filters. The tests also identified issues that still need to be addressed, such as evaluating performance on other configurations, optimizing sorbent usage (costs), and gathering longer-term operating data to address concerns about the impact of activated carbon on plant equipment and operations. The four sites identified for testing are Sunflower Electric's Holcomb Station, AmerenUE's Meramec Station, AEP's Conesville Station, and Detroit Edison's Monroe Power Plant. In addition to tests identified for the four main sites, parametric testing at Missouri Basin Power Project's Laramie River Station Unit 3 has been scheduled and made possible through additional costshare participation targeted by team members specifically for tests at Holcomb or a similar plant. This is the fifth quarterly report for this project. Long-term testing was completed at Meramec during this

  13. Modification to the accelerator of the NBI-1B ion source for improving the injection efficiency.

    PubMed

    Kim, T S; Jeong, S H; Chang, D H; In, S R; Park, M; Jung, B K; Lee, K W; Wang, S J; Bae, Y S; Park, H T; Kim, J S; Cho, W; Choi, D J

    2016-02-01

    Minimizing power loss of a neutral beam imposes modification of the accelerator of the ion source for further improvement of the beam optics. The beam optics can be improved by focusing beamlets. The injection efficiencies by the steering of ion beamlets are investigated numerically to find the optimum modification of the accelerator design of the NBI-1B ion source. The beam power loss was reduced by aperture displacement of three edge beamlets arrays considering power loadings on the beamline components. Successful testing and operation of the ion source at 60 keV/84% of injection efficiency led to the possibility of enhancing the system capability to a 2.4 MW power level at 100 keV/1.9 μP. PMID:26932045

  14. Modification to the accelerator of the NBI-1B ion source for improving the injection efficiency

    NASA Astrophysics Data System (ADS)

    Kim, T. S.; Jeong, S. H.; Chang, D. H.; In, S. R.; Park, M.; Jung, B. K.; Lee, K. W.; Wang, S. J.; Bae, Y. S.; Park, H. T.; Kim, J. S.; Cho, W.; Choi, D. J.

    2016-02-01

    Minimizing power loss of a neutral beam imposes modification of the accelerator of the ion source for further improvement of the beam optics. The beam optics can be improved by focusing beamlets. The injection efficiencies by the steering of ion beamlets are investigated numerically to find the optimum modification of the accelerator design of the NBI-1B ion source. The beam power loss was reduced by aperture displacement of three edge beamlets arrays considering power loadings on the beamline components. Successful testing and operation of the ion source at 60 keV/84% of injection efficiency led to the possibility of enhancing the system capability to a 2.4 MW power level at 100 keV/1.9 μP.

  15. Injection and acceleration of electron bunch in a plasma wakefield produced by a chirped laser pulse

    SciTech Connect

    Afhami, Saeedeh; Eslami, Esmaeil

    2014-06-15

    An ultrashort laser pulse propagating in plasma can excite a nonlinear plasma wakefield which can trap and accelerate charged particles up to GeV. One-dimensional analysis of electron injection, trapping, and acceleration by different chirped pulses propagating in plasma is investigated numerically. In this paper, we inject electron bunches in front of the chirped pulses. It is indicated that periodical chirped laser pulse can trap electrons earlier than other pulses. It is shown that periodical chirped laser pulses lead to decrease the minimum momentum necessary to trap the electrons. This is due to the fact that periodical chirped laser pulses are globally much efficient than nonchirped pulses in the wakefield generation. It is found that chirped laser pulses could lead to much larger electron energy than that of nonchirped pulses. Relative energy spread has a lower value in the case of periodical chirped laser pulses.

  16. Alkaline sorbent injection for mercury control

    DOEpatents

    Madden, Deborah A.; Holmes, Michael J.

    2002-01-01

    A mercury removal system for removing mercury from combustion flue gases is provided in which alkaline sorbents at generally extremely low stoichiometric molar ratios of alkaline earth or an alkali metal to sulfur of less than 1.0 are injected into a power plant system at one or more locations to remove at least between about 40% and 60% of the mercury content from combustion flue gases. Small amounts of alkaline sorbents are injected into the flue gas stream at a relatively low rate. A particulate filter is used to remove mercury-containing particles downstream of each injection point used in the power plant system.

  17. Alkaline sorbent injection for mercury control

    DOEpatents

    Madden, Deborah A.; Holmes, Michael J.

    2003-01-01

    A mercury removal system for removing mercury from combustion flue gases is provided in which alkaline sorbents at generally extremely low stoichiometric molar ratios of alkaline earth or an alkali metal to sulfur of less than 1.0 are injected into a power plant system at one or more locations to remove at least between about 40% and 60% of the mercury content from combustion flue gases. Small amounts of alkaline sorbents are injected into the flue gas stream at a relatively low rate. A particulate filter is used to remove mercury-containing particles downstream of each injection point used in the power plant system.

  18. FPGA-accelerated adaptive optics wavefront control

    NASA Astrophysics Data System (ADS)

    Mauch, S.; Reger, J.; Reinlein, C.; Appelfelder, M.; Goy, M.; Beckert, E.; Tünnermann, A.

    2014-03-01

    The speed of real-time adaptive optical systems is primarily restricted by the data processing hardware and computational aspects. Furthermore, the application of mirror layouts with increasing numbers of actuators reduces the bandwidth (speed) of the system and, thus, the number of applicable control algorithms. This burden turns out a key-impediment for deformable mirrors with continuous mirror surface and highly coupled actuator influence functions. In this regard, specialized hardware is necessary for high performance real-time control applications. Our approach to overcome this challenge is an adaptive optics system based on a Shack-Hartmann wavefront sensor (SHWFS) with a CameraLink interface. The data processing is based on a high performance Intel Core i7 Quadcore hard real-time Linux system. Employing a Xilinx Kintex-7 FPGA, an own developed PCie card is outlined in order to accelerate the analysis of a Shack-Hartmann Wavefront Sensor. A recently developed real-time capable spot detection algorithm evaluates the wavefront. The main features of the presented system are the reduction of latency and the acceleration of computation For example, matrix multiplications which in general are of complexity O(n3 are accelerated by using the DSP48 slices of the field-programmable gate array (FPGA) as well as a novel hardware implementation of the SHWFS algorithm. Further benefits are the Streaming SIMD Extensions (SSE) which intensively use the parallelization capability of the processor for further reducing the latency and increasing the bandwidth of the closed-loop. Due to this approach, up to 64 actuators of a deformable mirror can be handled and controlled without noticeable restriction from computational burdens.

  19. Toward automatic control of particle accelerator beams

    SciTech Connect

    Schultz, D.E.; Silbar, R.R.

    1988-01-01

    We describe a program aiming toward automatic control of particle accelerator beams. A hybrid approach is used, combining knowledge- based system programming techniques and traditional numerical simulations. We use an expert system shell for the symbolic processing and have incorporated the FORTRAN beam optics code TRANSPORT for numerical simulation. The paper discusses the symbolic model we built, the reasoning components, how the knowledge base accesses information from an operating beamline, and the experience gained in merging the two worlds of numeric and symbolic processing. We also discuss plans for a future real-time system. 6 refs., 6 figs.

  20. Open Hardware for CERN's accelerator control systems

    NASA Astrophysics Data System (ADS)

    van der Bij, E.; Serrano, J.; Wlostowski, T.; Cattin, M.; Gousiou, E.; Alvarez Sanchez, P.; Boccardi, A.; Voumard, N.; Penacoba, G.

    2012-01-01

    The accelerator control systems at CERN will be upgraded and many electronics modules such as analog and digital I/O, level converters and repeaters, serial links and timing modules are being redesigned. The new developments are based on the FPGA Mezzanine Card, PCI Express and VME64x standards while the Wishbone specification is used as a system on a chip bus. To attract partners, the projects are developed in an `Open' fashion. Within this Open Hardware project new ways of working with industry are being evaluated and it has been proven that industry can be involved at all stages, from design to production and support.

  1. 3D simulations of pre-ionized and two-stage ionization injected laser wakefield accelerators

    NASA Astrophysics Data System (ADS)

    Davidson, Asher; Zheng, Ming; Lu, Wei; Xu, Xinlu; Joshi, Chang; Silva, Luis O.; Martins, Joana; Fonseca, Ricardo; Mori, Warren B.

    2012-12-01

    In plasma based accelerators (LWFA and PWFA), the methods of injecting high quality electron bunches into the accelerating wakefield is of utmost importance for various applications. To fully understand the numerical effect of simulating the trapping process, numerous numerical convergence tests were performed to ensure the correctness of preionized simulations which confirm the physical picture first proposed in [1]. We Further investigate the use of a two-stage ionization injected LWFA to achieve high quality monoenergetic beams through the use of 3D PIC simulations. The first stage constitutes the Injection Regime, which is 99.5% He and 0.5% N, while the second stage constitutes the Acceleration Regime, which is entirely composed of He. Two of the simulations model the parameters of the LWFA experiments for the LLNL Callisto laser, at laser powers of 90 and 100TW. energies as high as 680MeV were observed in the 90TW simulation, and those as high as 1.44GeV were observed in the 100TW simulation. The affect of the matching condition of the spot size in this LWFA is discussed.

  2. Injection to Rapid Diffusive Shock Acceleration at Perpendicular Shocks in Partially Ionized Plasmas

    NASA Astrophysics Data System (ADS)

    Ohira, Yutaka

    2016-08-01

    We present a three-dimensional hybrid simulation of a collisionless perpendicular shock in a partially ionized plasma for the first time. In this simulation, the shock velocity and upstream ionization fraction are v sh ≈ 1333 km s‑1 and f i ˜ 0.5, which are typical values for isolated young supernova remnants (SNRs) in the interstellar medium. We confirm previous two-dimensional simulation results showing that downstream hydrogen atoms leak into the upstream region and are accelerated by the pickup process in the upstream region, and large magnetic field fluctuations are generated both in the upstream and downstream regions. In addition, we find that the magnetic field fluctuations have three-dimensional structures and the leaking hydrogen atoms are injected into the diffusive shock acceleration (DSA) at the perpendicular shock after the pickup process. The observed DSA can be interpreted as shock drift acceleration with scattering. In this simulation, particles are accelerated to v ˜ 100 v sh ˜ 0.3 c within ˜100 gyroperiods. The acceleration timescale is faster than that of DSA in parallel shocks. Our simulation results suggest that SNRs can accelerate cosmic rays to 1015.5 eV (the knee) during the Sedov phase.

  3. Injection to Rapid Diffusive Shock Acceleration at Perpendicular Shocks in Partially Ionized Plasmas

    NASA Astrophysics Data System (ADS)

    Ohira, Yutaka

    2016-08-01

    We present a three-dimensional hybrid simulation of a collisionless perpendicular shock in a partially ionized plasma for the first time. In this simulation, the shock velocity and upstream ionization fraction are v sh ≈ 1333 km s‑1 and f i ∼ 0.5, which are typical values for isolated young supernova remnants (SNRs) in the interstellar medium. We confirm previous two-dimensional simulation results showing that downstream hydrogen atoms leak into the upstream region and are accelerated by the pickup process in the upstream region, and large magnetic field fluctuations are generated both in the upstream and downstream regions. In addition, we find that the magnetic field fluctuations have three-dimensional structures and the leaking hydrogen atoms are injected into the diffusive shock acceleration (DSA) at the perpendicular shock after the pickup process. The observed DSA can be interpreted as shock drift acceleration with scattering. In this simulation, particles are accelerated to v ∼ 100 v sh ∼ 0.3 c within ∼100 gyroperiods. The acceleration timescale is faster than that of DSA in parallel shocks. Our simulation results suggest that SNRs can accelerate cosmic rays to 1015.5 eV (the knee) during the Sedov phase.

  4. Laser triggered injection of electrons in a laser wakefield accelerator with the colliding pulse method

    SciTech Connect

    Nakamura, K.; Fubiani, G.; Geddes, C.G.R.; Michel, P.; van Tilborg, J.; Toth, C.; Esarey, E.; Schroeder, C.B.; Leemans, W.P.

    2004-10-22

    An injection scheme for a laser wakefield accelerator that employs a counter propagating laser (colliding with the drive laser pulse, used to generate a plasma wake) is discussed. The threshold laser intensity for electron injection into the wakefield was analyzed using a heuristic model based on phase-space island overlap. Analysis shows that the injection can be performed using modest counter propagating laser intensity a{sub 1} < 0.5 for a drive laser intensity of a{sub 0} = 1.0. Preliminary experiments were preformed using a drive beam and colliding beam. Charge enhancement by the colliding pulse was observed. Increasing the signal-to-noise ratio by means of a preformed plasma channel is discussed.

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

    NASA Astrophysics Data System (ADS)

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

    2010-10-01

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

  6. Front-to-end simulations of the design of a laser wakefield accelerator with external injection

    SciTech Connect

    Urbanus, W.H.; Dijk, W. van; Geer, S.B. van der; Brussaard, G.J.H.; Wiel, M.J. van der

    2006-06-01

    We report the design of a laser wakefield accelerator (LWA) with external injection by a rf photogun and acceleration by a linear wakefield in a capillary discharge channel. The design process is complex due to the large number of intricately coupled free parameters. To alleviate this problem, we performed front-to-end simulations of the complete system. The tool we used was the general particle-tracking code, extended with a module representing the linear wakefield by a two-dimensional traveling wave with appropriate wavelength and amplitude. Given the limitations of existing technology for the longest discharge plasma wavelength ({approx}50 {mu}m) and shortest electron bunch length ({approx}100 {mu}m), we studied the regime in which the wakefield acts as slicer and buncher, while rejecting a large fraction of the injected bunch. The optimized parameters for the injected bunch are 10 pC, 300 fs at 6.7 MeV, to be injected into a 70 mm long channel at a plasma density of 7x10{sup 23} m{sup -3}. A linear wakefield is generated by a 2 TW laser focused to 30 {mu}m. The simulations predict an accelerated output of 0.6 pC, 10 fs bunches at 90 MeV, with energy spread below 10%. The design is currently being implemented. The design process also led to an important conclusion: output specifications directly comparable to those reported recently from 'laser-into-gas jet' experiments are feasible, provided the performance of the rf photogun is considerably enhanced. The paper outlines a photogun design providing such a performance level.

  7. Controlled Microwave Heating Accelerates Rolling Circle Amplification

    PubMed Central

    Yoshimura, Takeo; Suzuki, Takamasa; Mineki, Shigeru; Ohuchi, Shokichi

    2015-01-01

    Rolling circle amplification (RCA) generates single-stranded DNAs or RNA, and the diverse applications of this isothermal technique range from the sensitive detection of nucleic acids to analysis of single nucleotide polymorphisms. Microwave chemistry is widely applied to increase reaction rate as well as product yield and purity. The objectives of the present research were to apply microwave heating to RCA and indicate factors that contribute to the microwave selective heating effect. The microwave reaction temperature was strictly controlled using a microwave applicator optimized for enzymatic-scale reactions. Here, we showed that microwave-assisted RCA reactions catalyzed by either of the four thermostable DNA polymerases were accelerated over 4-folds compared with conventional RCA. Furthermore, the temperatures of the individual buffer components were specifically influenced by microwave heating. We concluded that microwave heating accelerated isothermal RCA of DNA because of the differential heating mechanisms of microwaves on the temperatures of reaction components, although the overall reaction temperatures were the same. PMID:26348227

  8. Reliable timing systems for computer controlled accelerators

    NASA Astrophysics Data System (ADS)

    Knott, Jürgen; Nettleton, Robert

    1986-06-01

    Over the past decade the use of computers has set new standards for control systems of accelerators with ever increasing complexity coupled with stringent reliability criteria. In fact, with very slow cycling machines or storage rings any erratic operation or timing pulse will cause the loss of precious particles and waste hours of time and effort of preparation. Thus, for the CERN linac and LEAR (Low Energy Antiproton Ring) timing system reliability becomes a crucial factor in the sense that all components must operate practically without fault for very long periods compared to the effective machine cycle. This has been achieved by careful selection of components and design well below thermal and electrical limits, using error detection and correction where possible, as well as developing "safe" decoding techniques for serial data trains. Further, consistent structuring had to be applied in order to obtain simple and flexible modular configurations with very few components on critical paths and to minimize the exchange of information to synchronize accelerators. In addition, this structuring allows the development of efficient strategies for on-line and off-line fault diagnostics. As a result, the timing system for Linac 2 has, so far, been operating without fault for three years, the one for LEAR more than one year since its final debugging.

  9. Ion Acceleration at the Quasi-parallel Bow Shock: Decoding the Signature of Injection

    NASA Astrophysics Data System (ADS)

    Sundberg, Torbjörn; Haynes, Christopher T.; Burgess, D.; Mazelle, Christian X.

    2016-03-01

    Collisionless shocks are efficient particle accelerators. At Earth, ions with energies exceeding 100 keV are seen upstream of the bow shock when the magnetic geometry is quasi-parallel, and large-scale supernova remnant shocks can accelerate ions into cosmic-ray energies. This energization is attributed to diffusive shock acceleration however, for this process to become active, the ions must first be sufficiently energized. How and where this initial acceleration takes place has been one of the key unresolved issues in shock acceleration theory. Using Cluster spacecraft observations, we study the signatures of ion reflection events in the turbulent transition layer upstream of the terrestrial bow shock, and with the support of a hybrid simulation of the shock, we show that these reflection signatures are characteristic of the first step in the ion injection process. These reflection events develop in particular in the region where the trailing edge of large-amplitude upstream waves intercept the local shock ramp and the upstream magnetic field changes from quasi-perpendicular to quasi-parallel. The dispersed ion velocity signature observed can be attributed to a rapid succession of ion reflections at this wave boundary. After the ions’ initial interaction with the shock, they flow upstream along the quasi-parallel magnetic field. Each subsequent wavefront in the upstream region will sweep the ions back toward the shock, where they gain energy with each transition between the upstream and the shock wave frames. Within three to five gyroperiods, some ions have gained enough parallel velocity to escape upstream, thus completing the injection process.

  10. Method for controlling corrosion in thermal vapor injection gases

    DOEpatents

    Sperry, John S.; Krajicek, Richard W.

    1981-01-01

    An improvement in the method for producing high pressure thermal vapor streams from combustion gases for injection into subterranean oil producing formations to stimulate the production of viscous minerals is described. The improvement involves controlling corrosion in such thermal vapor gases by injecting water near the flame in the combustion zone and injecting ammonia into a vapor producing vessel to contact the combustion gases exiting the combustion chamber.

  11. Acceleration-Augmented LQG Control of an Active Magnetic Bearing

    NASA Technical Reports Server (NTRS)

    Feeley, Joseph J.

    1993-01-01

    A linear-quadratic-gaussian (LQG) regulator controller design for an acceleration-augmented active magnetic bearing (AMB) is outlined. Acceleration augmentation is a key feature in providing improved dynamic performance of the controller. The optimal control formulation provides a convenient method of trading-off fast transient response and force attenuation as control objectives.

  12. Accelerator diagnosis and control by Neural Nets

    SciTech Connect

    Spencer, J.E.

    1989-01-01

    Neural Nets (NN) have been described as a solution looking for a problem. In the last conference, Artificial Intelligence (AI) was considered in the accelerator context. While good for local surveillance and control, its use for large complex systems (LCS) was much more restricted. By contrast, NN provide a good metaphor for LCS. It can be argued that they are logically equivalent to multi-loop feedback/forward control of faulty systems, and therefore provide an ideal adaptive control system. Thus, where AI may be good for maintaining a 'golden orbit,' NN should be good for obtaining it via a quantitative approach to 'look and adjust' methods like operator tweaking which use pattern recognition to deal with hardware and software limitations, inaccuracies or errors as well as imprecise knowledge or understanding of effects like annealing and hysteresis. Further, insights from NN allow one to define feasibility conditions for LCS in terms of design constraints and tolerances. Hardware and software implications are discussed and several LCS of current interest are compared and contrasted. 15 refs., 5 figs.

  13. Turbulent shear control with oscillatory bubble injection

    NASA Astrophysics Data System (ADS)

    Park, Hyun Jin; Oishi, Yoshihiko; Tasaka, Yuji; Murai, Yuichi; Takeda, Yasushi

    2009-02-01

    It is known that injecting bubbles into shear flow can reduce the frictional drag. This method has advantages in comparison to others in simplicity of installation and also in environment. The amount of drag reduction by bubbles depends on the void fraction provided in the boundary layer. It means, however, that certain power must be consumed to generate bubbles in water, worsening the total power-saving performance. We propose oscillatory bubble injection technique to improve the performance in this study. In order to prove this idea of new type of drag reduction, velocity vector field and shear stress profile in a horizontal channel flow are measured by ultrasonic velocity profiler (UVP) and shear stress transducer, respectively. We measure the gas-liquid interface from the UVP signal, as well. This compound measurement with different principles leads to deeper understanding of bubble-originated drag reduction phenomena, in particular for unsteady process of boundary layer alternation. At these experiments, the results have demonstrated that the intermittency promotes the drag reduction more than normal continuous injection for the same void fraction supplied.

  14. Closed-Loop Control of Chemical Injection Rate for a Direct Nozzle Injection System

    PubMed Central

    Cai, Xiang; Walgenbach, Martin; Doerpmond, Malte; Schulze Lammers, Peter; Sun, Yurui

    2016-01-01

    To realize site-specific and variable-rate application of agricultural pesticides, accurately metering and controlling the chemical injection rate is necessary. This study presents a prototype of a direct nozzle injection system (DNIS) by which chemical concentration transport lag was greatly reduced. In this system, a rapid-reacting solenoid valve (RRV) was utilized for injecting chemicals, driven by a pulse-width modulation (PWM) signal at 100 Hz, so with varying pulse width the chemical injection rate could be adjusted. Meanwhile, a closed-loop control strategy, proportional-integral-derivative (PID) method, was applied for metering and stabilizing the chemical injection rate. In order to measure chemical flow rates and input them into the controller as a feedback in real-time, a thermodynamic flowmeter that was independent of chemical viscosity was used. Laboratory tests were conducted to assess the performance of DNIS and PID control strategy. Due to the nonlinear input–output characteristics of the RRV, a two-phase PID control process obtained better effects as compared with single PID control strategy. Test results also indicated that the set-point chemical flow rate could be achieved within less than 4 s, and the output stability was improved compared to the case without control strategy. PMID:26805833

  15. Closed-Loop Control of Chemical Injection Rate for a Direct Nozzle Injection System.

    PubMed

    Cai, Xiang; Walgenbach, Martin; Doerpmond, Malte; Schulze Lammers, Peter; Sun, Yurui

    2016-01-01

    To realize site-specific and variable-rate application of agricultural pesticides, accurately metering and controlling the chemical injection rate is necessary. This study presents a prototype of a direct nozzle injection system (DNIS) by which chemical concentration transport lag was greatly reduced. In this system, a rapid-reacting solenoid valve (RRV) was utilized for injecting chemicals, driven by a pulse-width modulation (PWM) signal at 100 Hz, so with varying pulse width the chemical injection rate could be adjusted. Meanwhile, a closed-loop control strategy, proportional-integral-derivative (PID) method, was applied for metering and stabilizing the chemical injection rate. In order to measure chemical flow rates and input them into the controller as a feedback in real-time, a thermodynamic flowmeter that was independent of chemical viscosity was used. Laboratory tests were conducted to assess the performance of DNIS and PID control strategy. Due to the nonlinear input-output characteristics of the RRV, a two-phase PID control process obtained better effects as compared with single PID control strategy. Test results also indicated that the set-point chemical flow rate could be achieved within less than 4 s, and the output stability was improved compared to the case without control strategy. PMID:26805833

  16. Direct Observation of the Injection Dynamics of a Laser Wakefield Accelerator Using Few-Femtosecond Shadowgraphy.

    PubMed

    Sävert, A; Mangles, S P D; Schnell, M; Siminos, E; Cole, J M; Leier, M; Reuter, M; Schwab, M B; Möller, M; Poder, K; Jäckel, O; Paulus, G G; Spielmann, C; Skupin, S; Najmudin, Z; Kaluza, M C

    2015-07-31

    We present few-femtosecond shadowgraphic snapshots taken during the nonlinear evolution of the plasma wave in a laser wakefield accelerator with transverse synchronized few-cycle probe pulses. These snapshots can be directly associated with the electron density distribution within the plasma wave and give quantitative information about its size and shape. Our results show that self-injection of electrons into the first plasma-wave period is induced by a lengthening of the first plasma period. Three-dimensional particle-in-cell simulations support our observations. PMID:26274425

  17. Transverse Electron Motion and Multiple Electron Injection in Blowout Bubble of Laser Wakefield Accelerator

    NASA Astrophysics Data System (ADS)

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

    2010-11-01

    An analytical formula for electron motion in a spherical bubble was compared with data from electron acceleration experiments using the HERCULES laser system showing reasonable agreement. This also provides evidence for continuous injection of electrons into the bubble with multiple bunches in the bubble separated both transversely and longitudinally. The only free parameter in the analytical model was radius of the bubble (rb) which was found to be close to the matched spot size for self focusing. The RMS electron beam divergence is found to increase with bunch charge also suggesting tradeoff between beam divergence and photon number in applications for such beams as an x-ray source.

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

    ERIC Educational Resources Information Center

    Rogers, Dana B.; And Others

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

  19. Properties and parameters of the electron beam injected into the mirror magnetic trap of a plasma accelerator

    NASA Astrophysics Data System (ADS)

    Andreev, V. V.; Novitsky, A. A.; Vinnichenko, L. A.; Umnov, A. M.; Ndong, D. O.

    2016-03-01

    The parameters of the injector of an axial plasma beam injected into a plasma accelerator operating on the basis of gyroresonance acceleration of electrons in the reverse magnetic field are determined. The trapping of the beam electrons into the regime of gyroresonance acceleration is numerically simulated by the particle- in-cell method. The optimal time of axial injection of the beam into a magnetic mirror trap is determined. The beam parameters satisfying the condition of efficient particle trapping into the gyromagnetic autoresonance regime are found.

  20. Numerical Modeling of Fuel Injection into an Accelerating, Turning Flow with a Cavity

    NASA Astrophysics Data System (ADS)

    Colcord, Ben James

    Deliberate continuation of the combustion in the turbine passages of a gas turbine engine has the potential to increase the efficiency and the specific thrust or power of current gas-turbine engines. This concept, known as a turbine-burner, must overcome many challenges before becoming a viable product. One major challenge is the injection, mixing, ignition, and burning of fuel within a short residence time in a turbine passage characterized by large three-dimensional accelerations. One method of increasing the residence time is to inject the fuel into a cavity adjacent to the turbine passage, creating a low-speed zone for mixing and combustion. This situation is simulated numerically, with the turbine passage modeled as a turning, converging channel flow of high-temperature, vitiated air adjacent to a cavity. Both two- and three-dimensional, reacting and non-reacting calculations are performed, examining the effects of channel curvature and convergence, fuel and additional air injection configurations, and inlet conditions. Two-dimensional, non-reacting calculations show that higher aspect ratio cavities improve the fluid interaction between the channel flow and the cavity, and that the cavity dimensions are important for enhancing the mixing. Two-dimensional, reacting calculations show that converging channels improve the combustion efficiency. Channel curvature can be either beneficial or detrimental to combustion efficiency, depending on the location of the cavity and the fuel and air injection configuration. Three-dimensional, reacting calculations show that injecting fuel and air so as to disrupt the natural motion of the cavity stimulates three-dimensional instability and improves the combustion efficiency.

  1. Injection of κ-like suprathermal particles into diffusive shock acceleration

    SciTech Connect

    Kang, Hyesung; Petrosian, Vahé; Ryu, Dongsu; Jones, T. W. E-mail: vahe@stanford.edu E-mail: twj@msi.umn.edu

    2014-06-20

    We consider a phenomenological model for the thermal leakage injection in the diffusive shock acceleration (DSA) process, in which suprathermal protons and electrons near the shock transition zone are assumed to have the so-called κ-distributions produced by interactions of background thermal particles with pre-existing and/or self-excited plasma/MHD waves or turbulence. The κ-distribution has a power-law tail, instead of an exponential cutoff, well above the thermal peak momentum. So there are a larger number of potential seed particles with momentum, above that required for participation in the DSA process. As a result, the injection fraction for the κ-distribution depends on the shock Mach number much less severely compared to that for the Maxwellian distribution. Thus, the existence of κ-like suprathermal tails at shocks would ease the problem of extremely low injection fractions, especially for electrons and especially at weak shocks such as those found in the intracluster medium. We suggest that the injection fraction for protons ranges 10{sup –4}-10{sup –3} for a κ-distribution with 10 ≲ κ {sub p} ≲ 30 at quasi-parallel shocks, while the injection fraction for electrons becomes 10{sup –6}-10{sup –5} for a κ-distribution with κ {sub e} ≲ 2 at quasi-perpendicular shocks. For such κ values the ratio of cosmic ray (CR) electrons to protons naturally becomes K {sub e/p} ∼ 10{sup –3}-10{sup –2}, which is required to explain the observed ratio for Galactic CRs.

  2. High-quality electron beams from beam-driven plasma accelerators by wakefield-induced ionization injection.

    PubMed

    Martinez de la Ossa, A; Grebenyuk, J; Mehrling, T; Schaper, L; Osterhoff, J

    2013-12-13

    We propose a new and simple strategy for controlled ionization-induced trapping of electrons in a beam-driven plasma accelerator. The presented method directly exploits electric wakefields to ionize electrons from a dopant gas and capture them into a well-defined volume of the accelerating and focusing wake phase, leading to high-quality witness bunches. This injection principle is explained by example of three-dimensional particle-in-cell calculations using the code OSIRIS. In these simulations a high-current-density electron-beam driver excites plasma waves in the blowout regime inside a fully ionized hydrogen plasma of density 5×10(17)cm-3. Within an embedded 100  μm long plasma column contaminated with neutral helium gas, the wakefields trigger ionization, trapping of a defined fraction of the released electrons, and subsequent acceleration. The hereby generated electron beam features a 1.5 kA peak current, 1.5  μm transverse normalized emittance, an uncorrelated energy spread of 0.3% on a GeV-energy scale, and few femtosecond bunch length. PMID:24483670

  3. Simulating the effects of timing and energy stability in a laser wakefield accelerator with external injection

    SciTech Connect

    Dijk, W. van; Corstens, J. M.; Stragier, X. F. D.; Brussaard, G. J. H.; Geer, S. B. van der

    2009-01-22

    One of the most compelling reasons to use external injection of electrons into a laser wakefield accelerator is to improve the stability and reproducibility of the accelerated electrons. We have built a simulation tool based on particle tracking to investigate the expected output parameters. Specifically, we are simulating the variations in energy and bunch charge under the influence of variations in laser power and timing jitter. In these simulations a a{sub 0} = 0.32 to a{sub 0} = 1.02 laser pulse with 10% shot-to-shot energy fluctuation is focused into a plasma waveguide with a density of 1.0x10{sup 24} m{sup -3} and a calculated matched spot size of 50.2 {mu}m. The timing of the injected electron bunch with respect to the laser pulse is varied from up to 1 ps from the standard timing (1 ps ahead or behind the laser pulse, depending on the regime). The simulation method and first results will be presented. Shortcomings and possible extensions to the model will be discussed.

  4. A Microcomputer-Controlled Measurement of Acceleration.

    ERIC Educational Resources Information Center

    Crandall, A. Jared; Stoner, Ronald

    1982-01-01

    Describes apparatus and method used to allow rapid and repeated measurement of acceleration of a ball rolling down an inclined plane. Acceleration measurements can be performed in an hour with the apparatus interfaced to a Commodore PET microcomputer. A copy of the BASIC program is available from the authors. (Author/JN)

  5. Ionization Injection of Electrons into a Plasma Wakefield Accelerator at FACET

    NASA Astrophysics Data System (ADS)

    Clayton, Chris; E-200 At Facet Collaboration

    2013-10-01

    In the PWFA experiments at FACET, a low ionization-potential (IP) metal vapor gas (Li) is confined within a heat-pipe oven by a higher IP buffer gas (typically He). The Li is easily field-ionized by the FACET beam. A non-linear wake is formed in the blowout regime when the 20.3 GeV bunch containing 2e10 electrons in a σz ~ 30 μm is focused to a (vacuum) σr < 25 near the ~ 10cm-long boundary region. There the Li density rises from zero up to the oven's 30cm-long flat-topped density of 2.5e17 cm-3. To obtain a mono-energetic beam from accelerated ionization-injected electrons at the far end of the oven--the goal of this experiment--it is necessary for the FACET beam to have a betatron pinch just where the flat-topped region begins; i.e., where the wake wavelength is no longer changing. If the buffer gas contains a mixture of He and a moderate IP gas, the ``impurity'' gases will also be field ionized and potentially contribute more charge to the injected bunch than with He alone. Moderate IP gases were added to the He buffer gas: 10%, 20%, and 50% Ar (balance He) and 30% Ne (balance He) have been used. Evidence for ionization injection and acceleration appears through the observation of distinct features, characterized by their very narrow size and thus angular spread, at the image plane of a magnetic imaging spectrometer. Analysis aimed at characterizing these features with respect to energy, charge, and angular spread is underway and will be presented. This work was supported by the DOE and the NSF.

  6. Field Demonstration of Enhanced Sorbent Injection for Mercury Control

    SciTech Connect

    Shin Kang; Robert Schrecengost

    2009-01-07

    Alstom Power Inc. has conducted a DOE/NETL-sponsored program (under DOE Cooperative Agreement No. DE-FC26-04NT42306) to demonstrate Mer-Cure{trademark}, one of Alstom's mercury control technologies for coal-fired boilers. Mer-Cure{trademark} utilizes a small amount of Mer-Clean{trademark} sorbent that is injected into the flue gas stream for oxidation and adsorption of gaseous mercury. Mer-Clean{trademark} sorbents are carbon-based and prepared with chemical additives that promote oxidation and capture of mercury. Mer-Cure{trademark} is unique in that the sorbent is injected into an environment where the mercury capture kinetics is accelerated. This full-scale demonstration program was comprised of three seven-week long test campaigns at three host sites including PacifiCorp's 240-MW{sub e} Dave Johnston Unit No.3 burning a Powder River Basin (PRB) coal, Basin Electric's 220-MW{sub e} Leland Olds Unit No.1 burning a North Dakota lignite, and Reliant Energy's 170-MW{sub e} Portland Unit No.1 burning an Eastern bituminous coal. All three boilers are equipped with electrostatic precipitators. The goals for this Round 2 program, established by DOE/NETL under the original solicitation, were to reduce the uncontrolled mercury emissions by 50 to 70% at a cost 25 to 50% lower than the previous target of $60,000/lb mercury removed. The results for all three host sites indicated that Mer-Cure{trademark} technology could achieve mercury removal of 90%. The estimated mercury removal costs were 25-92% lower than the benchmark of $60,000/lb mercury removed. The estimated costs for control, at sorbent cost of $1.25 to $2.00/lb respectively, are as follows: (1) Dave Johnston Unit No.3--$2,650 to $4,328/lb Hg removed (92.8% less than $60k/lb); (2) Leland Olds Unit No.1--$8,680 to $13,860/lb Hg removed (76.7% less than $60k/lb); and (3) Portland Unit No.1--$28,540 to $45,065/lb Hg removed (24.9% less than $60k/lb). In summary, the results from demonstration testing at all three host

  7. PARTICLE ACCELERATOR AND METHOD OF CONTROLLING THE TEMPERATURE THEREOF

    DOEpatents

    Neal, R.B.; Gallagher, W.J.

    1960-10-11

    A method and means for controlling the temperature of a particle accelerator and more particularly to the maintenance of a constant and uniform temperature throughout a particle accelerator is offered. The novel feature of the invention resides in the provision of two individual heating applications to the accelerator structure. The first heating application provided is substantially a duplication of the accelerator heat created from energization, this first application being employed only when the accelerator is de-energized thereby maintaining the accelerator temperature constant with regard to time whether the accelerator is energized or not. The second heating application provided is designed to add to either the first application or energization heat in a manner to create the same uniform temperature throughout all portions of the accelerator.

  8. Torque-based optimal acceleration control for electric vehicle

    NASA Astrophysics Data System (ADS)

    Lu, Dongbin; Ouyang, Minggao

    2014-03-01

    The existing research of the acceleration control mainly focuses on an optimization of the velocity trajectory with respect to a criterion formulation that weights acceleration time and fuel consumption. The minimum-fuel acceleration problem in conventional vehicle has been solved by Pontryagin's maximum principle and dynamic programming algorithm, respectively. The acceleration control with minimum energy consumption for battery electric vehicle(EV) has not been reported. In this paper, the permanent magnet synchronous motor(PMSM) is controlled by the field oriented control(FOC) method and the electric drive system for the EV(including the PMSM, the inverter and the battery) is modeled to favor over a detailed consumption map. The analytical algorithm is proposed to analyze the optimal acceleration control and the optimal torque versus speed curve in the acceleration process is obtained. Considering the acceleration time, a penalty function is introduced to realize a fast vehicle speed tracking. The optimal acceleration control is also addressed with dynamic programming(DP). This method can solve the optimal acceleration problem with precise time constraint, but it consumes a large amount of computation time. The EV used in simulation and experiment is a four-wheel hub motor drive electric vehicle. The simulation and experimental results show that the required battery energy has little difference between the acceleration control solved by analytical algorithm and that solved by DP, and is greatly reduced comparing with the constant pedal opening acceleration. The proposed analytical and DP algorithms can minimize the energy consumption in EV's acceleration process and the analytical algorithm is easy to be implemented in real-time control.

  9. Accelerated wound healing by injectable microporous gel scaffolds assembled from annealed building blocks

    PubMed Central

    Griffin, Donald R.; Weaver, Westbrook M.; Scumpia, Philip; Di Carlo, Dino; Segura, Tatiana

    2015-01-01

    Summary Injectable hydrogels can provide a scaffold for in situ tissue regrowth and regeneration, however these injected materials require gel degradation prior to tissue reformation limiting their ability to provide physical support. We have created a new class of injectable biomaterial that circumvents this challenge by providing an interconnected microporous network for simultaneous tissue reformation and material degradation. We assemble monodisperse micro-gel building blocks into an interconnected microporous annealed particle (MAP) scaffold. Through microfluidic formation, we tailor the chemical and physical properties of the building blocks, providing downstream control of the physical and chemical properties of the assembled MAP scaffold. In vitro, cells incorporated during MAP scaffold formation proliferated and formed extensive 3D networks within 48 hours. In vivo, the injectable MAP scaffold facilitated cell migration resulting in rapid cutaneous tissue regeneration and tissue structure formation within 5 days. The combination of microporosity and injectability achieved with MAP scaffolds will enable novel routes to tissue regeneration in vivo and tissue creation de novo. PMID:26030305

  10. Separation Control in a Multistage Compressor Using Impulsive Surface Injection

    NASA Technical Reports Server (NTRS)

    Wundrow, David W.; Braunscheidel, Edward P.; Culley, Dennis E.; Bright, Michelle M.

    2006-01-01

    Control of flow separation using impulsive surface injection is investigated within the multistage environment of a low speed axial-flow compressor. Measured wake profiles behind a set of embedded stator vanes treated with suction-surface injection indicate significant reduction in flow separation at a variety of injection-pulse repetition rates and durations. The corresponding total pressure losses across the vanes reveal a bank of repetition rates at each pulse duration where the separation control remains nearly complete. This persistence allows for demands on the injected-mass delivery system to be economized while still achieving effective flow control. The response of the stator-vane boundary layers to infrequently applied short injection pulses is described in terms of the periodic excitation of turbulent strips whose growth and propagation characteristics dictate the lower bound on the band of optimal pulse repetition rates. The eventual falloff in separation control at higher repetition rates is linked to a competition between the benefits of pulse-induced mixing and the aggravation caused by the periodic introduction of low-momentum fluid. Use of these observations for impulsive actuator design is discussed and their impact on modeling the time-average effect of impulsive surface injection for multistage steady-flow simulation is considered.

  11. FPGA-Based Multiprocessor System for Injection Molding Control

    PubMed Central

    Muñoz-Barron, Benigno; Morales-Velazquez, Luis; Romero-Troncoso, Rene J.; Rodriguez-Donate, Carlos; Trejo-Hernandez, Miguel; Benitez-Rangel, Juan P.; Osornio-Rios, Roque A.

    2012-01-01

    The plastic industry is a very important manufacturing sector and injection molding is a widely used forming method in that industry. The contribution of this work is the development of a strategy to retrofit control of an injection molding machine based on an embedded system microprocessors sensor network on a field programmable gate array (FPGA) device. Six types of embedded processors are included in the system: a smart-sensor processor, a micro fuzzy logic controller, a programmable logic controller, a system manager, an IO processor and a communication processor. Temperature, pressure and position are controlled by the proposed system and experimentation results show its feasibility and robustness. As validation of the present work, a particular sample was successfully injected. PMID:23202036

  12. FPGA-based multiprocessor system for injection molding control.

    PubMed

    Muñoz-Barron, Benigno; Morales-Velazquez, Luis; Romero-Troncoso, Rene J; Rodriguez-Donate, Carlos; Trejo-Hernandez, Miguel; Benitez-Rangel, Juan P; Osornio-Rios, Roque A

    2012-01-01

    The plastic industry is a very important manufacturing sector and injection molding is a widely used forming method in that industry. The contribution of this work is the development of a strategy to retrofit control of an injection molding machine based on an embedded system microprocessors sensor network on a field programmable gate array (FPGA) device. Six types of embedded processors are included in the system: a smart-sensor processor, a micro fuzzy logic controller, a programmable logic controller, a system manager, an IO processor and a communication processor. Temperature, pressure and position are controlled by the proposed system and experimentation results show its feasibility and robustness. As validation of the present work, a particular sample was successfully injected. PMID:23202036

  13. Low-energy-spread laser wakefield acceleration using ionization injection with a tightly focused laser in a mismatched plasma channel

    NASA Astrophysics Data System (ADS)

    Li, F.; Zhang, C. J.; Wan, Y.; Wu, Y. P.; Xu, X. L.; Hua, J. F.; Pai, C. H.; Lu, W.; Gu, Y. Q.; Mori, W. B.; Joshi, C.

    2016-03-01

    An improved ionization injection scheme for laser wakefield acceleration using a tightly focused laser pulse, with intensity near the ionization threshold to trigger the injection in a mismatched plasma channel, has been proposed and examined via 3D particle-in-cell (PIC) simulations. In this scheme, the key to achieving a very low energy spread is shortening the injection distance through the fast diffraction of the tightly focused laser. Furthermore, the oscillation of the laser envelope in the mismatched plasma channel can induce multiple low-energy-spread injections with an even distribution in both space and energy. The envelope oscillation can also significantly enhance the energy gain of the injected beams compared to the standard non-evolving wake scenario due to the rephasing between the electron beam and the laser wake. A theoretical model has been derived to precisely predict the injection distance, the ionization degree of injection atoms/ions, the electron yield as well as the ionized charge for given laser-plasma parameters, and such expressions can be directly utilized for optimizing the quality of the injected beam. Through 3D PIC simulations, we show that an injection distance as short as tens of microns can be achieved, which leads to ultrashort fs, few pC electron bunches with a narrow absolute energy spread around 2 MeV (rms). Simulations also show that the initial absolute energy spread remains nearly constant during the subsequent acceleration due to the very short bunch length, and this indicates that further acceleration of the electron bunches up to the GeV level may lead to an electron beam with an energy spread well below 0.5%. Such low-energy-spread electron beams may have potential applications for future coherent light sources driven by laser-plasma accelerators.

  14. Measurements of the critical power for self-injection of electrons in a laser wakefield accelerator

    SciTech Connect

    Froula, D H; Clayton, C E; Doppner, T; Fonseca, R A; Marsh, K A; Barty, C J; Divol, L; Glenzer, S H; Joshi, C; Lu, W; Martins, S F; Michel, P; Mori, W; Palastro, J P; Pollock, B B; Pak, A; Ralph, J E; Ross, J S; Siders, C; Silva, L O; Wang, T

    2009-06-02

    A laser wakefield acceleration study has been performed in the matched, self-guided, blow-out regime where a 10 J, 60 fs laser produced 720 {+-} 50 MeV quasi-monoenergetic electrons with a divergence of {Delta}{theta} = 2.85 {+-} 0.15 mRad. While maintaining a nearly constant plasma density (3 x 10{sup 18} cm{sup -3}), a linear electron energy gain was measured from 100 MeV to 700 MeV when the plasma length was scaled from 3 mm to 8 mm. Absolute charge measurements indicate that self-injection occurs when P/P{sub cr} > 4 and saturates around 100 pC for P/P{sub cr} > 12. The results are compared with both analytical scalings and full 3D particle-in-cell simulations.

  15. Measurements of the critical power for self-injection of electrons in a laser wakefield accelerator.

    PubMed

    Froula, D H; Clayton, C E; Döppner, T; Marsh, K A; Barty, C P J; Divol, L; Fonseca, R A; Glenzer, S H; Joshi, C; Lu, W; Martins, S F; Michel, P; Mori, W B; Palastro, J P; Pollock, B B; Pak, A; Ralph, J E; Ross, J S; Siders, C W; Silva, L O; Wang, T

    2009-11-20

    A laser wakefield acceleration study has been performed in the matched, self-guided, blowout regime producing 720 +/- 50 MeV quasimonoenergetic electrons with a divergence Deltatheta_{FWHM} of 2.85 +/- 0.15 mrad using a 10 J, 60 fs 0.8 microm laser. While maintaining a nearly constant plasma density (3 x 10{18} cm{-3}), the energy gain increased from 75 to 720 MeV when the plasma length was increased from 3 to 8 mm. Absolute charge measurements indicate that self-injection of electrons occurs when the laser power P exceeds 3 times the critical power P{cr} for relativistic self-focusing and saturates around 100 pC for P/P{cr} > 5. The results are compared with both analytical scalings and full 3D particle-in-cell simulations. PMID:20366048

  16. Measurements of the Critical Power for Self-Injection of Electrons in a Laser Wakefield Accelerator

    NASA Astrophysics Data System (ADS)

    Froula, D. H.; Clayton, C. E.; Döppner, T.; Marsh, K. A.; Barty, C. P. J.; Divol, L.; Fonseca, R. A.; Glenzer, S. H.; Joshi, C.; Lu, W.; Martins, S. F.; Michel, P.; Mori, W. B.; Palastro, J. P.; Pollock, B. B.; Pak, A.; Ralph, J. E.; Ross, J. S.; Siders, C. W.; Silva, L. O.; Wang, T.

    2009-11-01

    A laser wakefield acceleration study has been performed in the matched, self-guided, blowout regime producing 720±50MeV quasimonoenergetic electrons with a divergence ΔθFWHM of 2.85±0.15mrad using a 10 J, 60 fs 0.8μm laser. While maintaining a nearly constant plasma density (3×1018cm-3), the energy gain increased from 75 to 720 MeV when the plasma length was increased from 3 to 8 mm. Absolute charge measurements indicate that self-injection of electrons occurs when the laser power P exceeds 3 times the critical power Pcr for relativistic self-focusing and saturates around 100 pC for P/Pcr>5. The results are compared with both analytical scalings and full 3D particle-in-cell simulations.

  17. Simulation of direct plasma injection for laser ion beam acceleration with a radio frequency quadrupole

    SciTech Connect

    Jin, Q. Y.; Li, Zh. M.; Liu, W.; Zhao, H. Y. Zhang, J. J.; Sha, Sh.; Zhang, Zh. L.; Zhang, X. Zh.; Sun, L. T.; Zhao, H. W.

    2014-07-15

    The direct plasma injection scheme (DPIS) has been being studied at Institute of Modern Physics since several years ago. A C{sup 6+} beam with peak current of 13 mA, energy of 593 keV/u has been successfully achieved after acceleration with DPIS method. To understand the process of DPIS, some simulations have been done as follows. First, with the total current intensity and the relative yields of different charge states for carbon ions measured at the different distance from the target, the absolute current intensities and time-dependences for different charge states are scaled to the exit of the laser ion source in the DPIS. Then with these derived values as the input parameters, the extraction of carbon beam from the laser ion source to the radio frequency quadrupole with DPIS is simulated, which is well agreed with the experiment results.

  18. In Situ Oxalic Acid Injection to Accelerate Arsenic Remediation at a Superfund Site in New Jersey

    PubMed Central

    Wovkulich, Karen; Stute, Martin; Mailloux, Brian J.; Keimowitz, Alison R.; Ross, James; Bostick, Benjamin; Sun, Jing; Chillrud, Steven N.

    2015-01-01

    Arsenic is a prevalent contaminant at a large number of US Superfund sites; establishing techniques that accelerate As remediation could benefit many sites. Hundreds of tons of As were released into the environment by the Vineland Chemical Co. in southern New Jersey during its manufacturing lifetime (1949–1994), resulting in extensive contamination of surface and subsurface soils and sediments, groundwater, and the downstream watershed. Despite substantial intervention at this Superfund site, sufficient aquifer cleanup could require many decades if based on traditional pump and treat technologies only. Laboratory column experiments have suggested that oxalic acid addition to contaminated aquifer solids could promote significant As release from the solid phase. To evaluate the potential of chemical additions to increase As release in situ and boost treatment efficiency, a forced gradient pilot scale study was conducted on the Vineland site. During spring/summer 2009, oxalic acid and bromide tracer were injected into a small portion (~50 m2) of the site for 3 months. Groundwater samples indicate that introduction of oxalic acid led to increased As release. Between 2.9 and 3.6 kg of As were removed from the sampled wells as a result of the oxalic acid treatment during the 3-month injection. A comparison of As concentrations on sediment cores collected before and after treatment and analyzed using X-ray fluorescence spectroscopy suggested reduction in As concentrations of ~36% (median difference) to 48% (mean difference). While further study is necessary, the addition of oxalic acid shows potential for accelerating treatment of a highly contaminated site and decreasing the As remediation time-scale. PMID:25598701

  19. Beam Control for Ion Induction Accelerators

    SciTech Connect

    Sangster, T.C.; Ahle, L.

    2000-02-17

    Coordinated bending and acceleration of an intense space-charge-dominated ion beam has been achieved for the first time. This required the development of a variable waveform, precision, bi-polar high voltage pulser and a precision, high repetition rate induction core modulator. Waveforms applied to the induction cores accelerate the beam as the bi-polar high voltage pulser delivers a voltage ramp to electrostatic dipoles which bend the beam through a 90 degree permanent magnet quadrupole lattice. Further work on emittance minimization is also reported.

  20. High pressure common rail injection system modeling and control.

    PubMed

    Wang, H P; Zheng, D; Tian, Y

    2016-07-01

    In this paper modeling and common-rail pressure control of high pressure common rail injection system (HPCRIS) is presented. The proposed mathematical model of high pressure common rail injection system which contains three sub-systems: high pressure pump sub-model, common rail sub-model and injector sub-model is a relative complicated nonlinear system. The mathematical model is validated by the software Matlab and a virtual detailed simulation environment. For the considered HPCRIS, an effective model free controller which is called Extended State Observer - based intelligent Proportional Integral (ESO-based iPI) controller is designed. And this proposed method is composed mainly of the referred ESO observer, and a time delay estimation based iPI controller. Finally, to demonstrate the performances of the proposed controller, the proposed ESO-based iPI controller is compared with a conventional PID controller and ADRC. PMID:27012440

  1. A targeted controlled force injection of genetic material in vivo

    PubMed Central

    Ahlén, Gustaf; Frelin, Lars; Holmström, Fredrik; Smetham, Grant; Augustyn, Steve; Sällberg, Matti

    2016-01-01

    A general limitation in gene delivery is the cellular uptake in lager animals including humans. Several approaches have been tested including liposomes, micro-needles, in vivo electro-transfer, ballistic delivery, and needle-free delivery. All these techniques have individual limitations. One approach reproducibly delivering genetic material in muscle tissue in nonhuman primates is hydrodynamic injection, a forced injection of a volume equaling the volume of the tissue to be transfected thereby causing an increased local pressure resulting in an improved uptake of genetic material. We transferred the principle of hydrodynamic injection to a device, where a small injection volume can be delivered to a targeted tissue volume, termed in vivo intracellular injection (IVIN). The device is based on needle(s) with apertures along the needle shafts, where multiple needles can fix the tissue volume to be transfected. The apertures direct the injection from a central needle outward or inward to the centroid of a geometric arrangement thereby targeting the tissue to be transfected. With a controlled force, this results in a targeted injection with increased transfection efficiency. We here show that the IVIN technology reproducibly improved plasmid uptake and expression and the immunogenicity. The IVIN technology can be generally applied to a targeted delivery of genetic materials. PMID:27069951

  2. Clean beams from laser wake-field accelerators via optical injection with a cleanup pulse

    SciTech Connect

    Cary, John R.; Giacone, R.E.; Nieter, C.; Bruhwiler, D.L.

    2005-05-15

    Multiple colliding-pulse injection schemes have been proposed as means for trapping electrons in the ultrashort acceleration buckets of laser-generated wake fields. The primary goal of this paper is to present a parameter study to determine the beams that can be obtained through collisions of collinear laser pulses in uniform plasma. The parameter study is through fully self-consistent, two-dimensional, particle-in-cell simulations, as previous work used only test-particle computations. To remove the multiple beams that can commonly be generated in colliding pulse injection, we use a cleanup pulse, a trailing laser pulse that absorbs the wake. The wake then no longer exists in the region where the trailing beamlets would be, and so the trailing beamlets no longer form. A series of simulations predicts that with such one can obtain single, short ({<=}10 fs) beams with a bunch charge of order 10 pC, normalized emittance of order 2{pi} {mu}m, and energy spread of the order of 10%. The parameters of the beams are insensitive to the amplitude of the backward pulse above normalized amplitudes of a{sub bw}{approx_equal}0.4.

  3. Acceleration and injection of particles inside the magnetosphere changes during duskward IMF By: statistical approach

    NASA Astrophysics Data System (ADS)

    Yan, X.; Cai, D.; Lembege, B.; Nishikawa, K.

    2005-12-01

    The change of the interplanetary magnetic field (IMF) direction from northward to duskward has an important impact on the inner magnetosphere as analyzed in a recent paper [Yan et al, GRL, to appear] . This impact is analyzed with the help of a new parallel version of the global three-dimensional full particle simulation. As the newly duskward-oriented IMF interacts with the magnetosphere, bands of weak magnetic field (sash) move to the equator (within opposite quadrants), reach lower latitude and merge into each other to form characteristic ``Crosstail-S" structures within the neutral sheet of the magnetotail. The analysis of particle fluxes shows that ``sashs" and ``Crosstail-S" act as magnetic groove to facilitate the entry and injection of magnetosheath particles into the inner magnetosphere. Injected particles are accelerated after the IMF changes its direction from northward to duskward. Characteristic times associated to the changes of the particle dynamics are estimated from the simulations. These informations are thought to be helpful as pre-signatures announcing the triggering of magnetic substorms.

  4. Novel technique for injecting and extracting beams in a circular hadron accelerator without using septum magnets

    NASA Astrophysics Data System (ADS)

    Franchi, Andrea; Giovannozzi, Massimo

    2015-07-01

    With a few exceptions, all on-axis injection and extraction schemes implemented in circular particle accelerators, synchrotrons, and storage rings, make use of magnetic and electrostatic septa with systems of slow-pulsing dipoles acting on tens of thousands of turns and fast-pulsing dipoles on just a few. The dipoles create a closed orbit deformation around the septa, usually referred to as an orbit bump. A new approach is presented which obviates the need for the septum deflectors. Fast-pulsing elements are still required, but their strength can be minimized by choosing appropriate local accelerator optics. This technique should increase the beam clearance and reduce the usually high radiation levels found around the septa and also reduce the machine impedance introduced by the fast-pulsing dipoles. The basis of the technique is the creation of stable islands around stable fixed points in horizontal phase space. The trajectories of these islands may then be adjusted to match the position and angle of the incoming or outgoing beam.

  5. NOx Sensor for Direct Injection Emission Control

    SciTech Connect

    Betteridge, William J

    2006-02-28

    The Electricore/Delphi team continues to leverage the electrochemical planar sensor technology that has produced stoichiometric planar and wide range oxygen sensors as the basis for development of a NOx sensor. Zirconia cell technology with an integrated heater will provide the foundation for the sensor structure. Proven materials and packaging technology will help to ensure a cost-effective approach to the manufacture of this sensor. The electronics technique and interface is considered to be an area where new strategies need to be employed to produce higher S/N ratios of the NOx signal with emphasis on signal stability over time for robustness and durability Both continuous mode and pulse mode control techniques are being evaluated. Packaging the electronics requires careful design and circuit partitioning so that only the necessary signal conditioning electronics are coupled directly in the wiring harness, while the remainder is situated within the ECM for durability and costs reasons. This task continues to be on hold due to the limitation that the definition of the interface electronics was unavailable until very late in the project. The sense element is based on the amperometric method utilizing integrated alumina and zirconia ceramics. Precious metal electrodes are used to form the integrated heater, the cell electrodes and leads. Inside the actual sense cell structure, it is first necessary to separate NOx from the remaining oxygen constituents of the exhaust, without reducing the NOx. Once separated, the NOx will be measured using a measurement cell. Development or test coupons have been used to facilitate material selection and refinement, cell, diffusion barrier, and chamber development. The sense element currently requires elaborate interconnections. To facilitate a robust durable connection, mechanical and metallurgical connections are under investigation. Materials and process refinements continue to play an important role in the development of the

  6. Failure Mode Effects Analysis for an Accelerator Control System

    SciTech Connect

    Hartman, Steven M

    2009-01-01

    Failure mode effects analysis (FMEA) has been used in industry for design, manufacturing and assembly process quality control. It describes a formal approach for categorizing how a process may fail and for prioritizing failures based on their severity, frequency and likelihood of detection. Experience conducting a partial FMEA of an accelerator subsystem and its related control system will be reviewed. The applicability of the FMEA process to an operational accelerator control system will be discussed.

  7. Simulation Study Using an Injection Phase-locked Magnetron as an Alternative Source for SRF Accelerators

    SciTech Connect

    Wang, Haipeng; Plawski, Tomasz E.; Rimmer, Robert A.

    2015-09-01

    As a drop-in replacement for the CEBAF CW klystron system, a 1497 MHz, CW-type high-efficiency magnetron using injection phase lock and amplitude variation is attractive. Amplitude control using magnetic field trimming and anode voltage modulation has been studied using analytical models and MATLAB/Simulink simulations. Since the 1497 MHz magnetron has not been built yet, previously measured characteristics of a 2.45GHz cooker magnetron are used as reference. The results of linear responses to the amplitude and phase control of a superconducting RF (SRF) cavity, and the expected overall benefit for the current CEBAF and future MEIC RF systems are presented in this paper.

  8. FURNACE INJECTION OF ALKALINE SORBENTS FOR SULFURIC ACID CONTROL

    SciTech Connect

    Gary M. Blythe

    2000-12-01

    This document summarizes progress on the Cooperative Agreement DE-FC26-99FT40718, Furnace Injection of Alkaline Sorbents for Sulfuric Acid Control, during the time period April 1, 2000 through September 30, 2000. The objective of this project is to demonstrate the use of alkaline reagents injected into the furnace of coal-fired boilers as a means of controlling sulfuric acid emissions. The coincident removal of hydrochloric acid and hydrofluoric acid will also be determined, as will the removal of arsenic, a known poison for NOX selective catalytic reduction (SCR) catalysts. EPRI, the Tennessee Valley Authority (TVA), First Energy Corporation, and the Dravo Lime Company are project co-funders. URS Corporation is the prime contractor. This is the second reporting period for the subject Cooperative Agreement. During this period, the first of four short-term sorbent injection tests were conducted at the First Energy Bruce Mansfield Plant. This test determined the effectiveness of dolomite injection through out-of-service burners as a means of controlling sulfuric acid emissions from this unit. The tests showed that dolomite injection could achieve up to 95% sulfuric acid removal. Balance of plant impacts on furnace slagging and fouling, air heater fouling, ash loss-on-ignition, and the flue gas desulfurization system were also determined. These results are presented and discussed in this report.

  9. NODAL — The second life of the accelerator control language

    NASA Astrophysics Data System (ADS)

    Cuisinier, G.; Perriollat, F.; Ribeiro, P.; Kagarmanov, A.; Kovaltsov, V.

    1994-12-01

    NODAL has been a popular interpreter language for accelerator controls since the beginning of the 1970s. NODAL has been rewritten in the C language to be easily portable to the different computer platforms which are in use in accelerator controls. The paper describes the major features of this new version of NODAL, the major software packages which are available through this implementation, the platforms on which it is currently running, and some relevant performances. The experience gained during the rejuvenation project of the CERN accelerator control systems is presented. The benefit of this is discussed, in particular in a view of the prevailing strong constraints in personnel and money resources.

  10. Techniques for increasing the reliability of accelerator control system electronics

    SciTech Connect

    Utterback, J.

    1993-09-01

    As the physical size of modern accelerators becomes larger and larger, the number of required control system circuit boards increases, and the probability of one of those circuit boards failing while in service also increases. In order to do physics, the experimenters need the accelerator to provide beam reliably with as little down time as possible. With the advent of colliding beams physics, reliability becomes even more important due to the fact that a control system failure can cause the loss of painstakingly produced antiprotons. These facts prove the importance of keeping reliability in mind when designing and maintaining accelerator control system electronics.

  11. Control of diesel engine emissions by dilute oxidizer injection

    SciTech Connect

    Duva, A.W.; Ibrahim, O.; Zhang, Z.

    1996-12-31

    The current diesel engine power systems have progressed to the point where significant reduction in emissions or fuel consumption are at the limit of the state of the art with the present fuels. It is proposed that overall system weight, power or efficiency must be traded to achieve reduced exhaust emission levels. Emission control through the injection of dilute oxidizers are explored to minimize the formation of noxious gases, emission of unburned hydrocarbons and soot in internal combustion diesel cycle engines. Relevant literature detailing the attempts to control exhaust emissions by altering the intake charge are reviewed and utilized as the foundation for the current study. Steady flow type combustion simulations utilizing low concentration hydrogen peroxide with available air in varying ratios are presented for trend comparison to experimental data developed during this investigation. The empirical portion of the study focused on the adaptation of proposed dilute hydrogen peroxide injection to a standard four cylinder marine diesel engine. The main thrust evaluated the impact of oxidizer injection on an aging engine without significant modifications to the existing auxiliary equipment. A simple spray apparatus delivered the dilute hydrogen peroxide to the air intake stream to minimize the alterations to the existing system. Water injection was performed as an experimental control for comparison to reference literature and to normalize the results obtained from the injection of the 5% and 10% concentration hydrogen peroxide. The injection of both concentrations of hydrogen peroxide showed an improvement relative to water injection for unburned hydrocarbon and oxides of nitrogen emissions. The improvements relative to water was greater with the higher concentration of hydrogen peroxide.

  12. Accelerator control system at KEKB and the linac

    NASA Astrophysics Data System (ADS)

    Akiyama, Atsuyoshi; Furukawa, Kazuro; Kadokura, Eiichi; Kurashina, Miho; Mikawa, Katsuhiko; Nakamura, Tatsuro; Odagiri, Jun-ichi; Satoh, Masanori; Suwada, Tsuyoshi

    2013-03-01

    KEKB has completed all of the technical milestones and has offered important insights into the flavor structure of elementary particles, especially CP violation. The accelerator control system at KEKB and the injector linac was initiated by a combination of scripting languages at the operation layer and EPICS (experimental physics and industrial control system) at the equipment layer. During the project, many features were implemented to achieve extreme performance from the machine. In particular, the online linkage to the accelerator simulation played an essential role. In order to further improve the reliability and flexibility, two major concepts were additionally introduced later in the project, namely, channel access everywhere and dual-tier controls. Based on the improved control system, a virtual accelerator concept was realized, allowing the single injector linac to serve as three separate injectors to KEKB's high-energy ring, low-energy ring, and Photon Factory, respectively. These control technologies are indispensable for future particle accelerators.

  13. Laser-ion acceleration through controlled surface contamination

    SciTech Connect

    Hou Bixue; Nees, John A.; He Zhaohan; Easter, James H.; Thomas, Alexander G. R.; Krushelnick, Karl M.; Petrov, George; Davis, Jack

    2011-04-15

    In laser-plasma ion accelerators, control of target contamination layers can lead to selection of accelerated ion species and enhancement of acceleration. To demonstrate this, deuterons up to 75 keV are accelerated from an intense laser interaction with a glass target simply by placing 1 ml of heavy water inside the experimental chamber prior to pumping to generate a deuterated contamination layer on the target. Using the same technique with a deuterated-polystyrene-coated target also enhances deuteron yield by a factor of 3 to 5, while increasing the maximum energy of the generated deuterons to 140 keV.

  14. BNL ACCELERATOR TEST FACILITY CONTROL SYSTEM UPGRADE.

    SciTech Connect

    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.

  15. Neural Networks for Modeling and Control of Particle Accelerators

    DOE PAGESBeta

    Edelen, A. L.; Biedron, S. G.; Chase, B. E.; Edstrom, D.; Milton, S. V.; Stabile, P.

    2016-04-01

    Myriad nonlinear and complex physical phenomena are host to particle accelerators. They often involve a multitude of interacting systems, are subject to tight performance demands, and should be able to run for extended periods of time with minimal interruptions. Often times, traditional control techniques cannot fully meet these requirements. One promising avenue is to introduce machine learning and sophisticated control techniques inspired by artificial intelligence, particularly in light of recent theoretical and practical advances in these fields. Within machine learning and artificial intelligence, neural networks are particularly well-suited to modeling, control, and diagnostic analysis of complex, nonlinear, and time-varying systems,more » as well as systems with large parameter spaces. Consequently, the use of neural network-based modeling and control techniques could be of significant benefit to particle accelerators. For the same reasons, particle accelerators are also ideal test-beds for these techniques. Moreover, many early attempts to apply neural networks to particle accelerators yielded mixed results due to the relative immaturity of the technology for such tasks. For the purpose of this paper is to re-introduce neural networks to the particle accelerator community and report on some work in neural network control that is being conducted as part of a dedicated collaboration between Fermilab and Colorado State University (CSU). We also describe some of the challenges of particle accelerator control, highlight recent advances in neural network techniques, discuss some promising avenues for incorporating neural networks into particle accelerator control systems, and describe a neural network-based control system that is being developed for resonance control of an RF electron gun at the Fermilab Accelerator Science and Technology (FAST) facility, including initial experimental results from a benchmark controller.« less

  16. Flow monitoring and control system for injection wells

    DOEpatents

    Corey, J.C.

    1991-01-01

    The present invention relates to a system for monitoring and controlling the rate of fluid flow from an injection well used for in-situ remediation of contaminated groundwater. The United States Government has rights in this invention pursuant to Contract No. DE-AC09-89SR18035 between the US Department of Energy and Westinghouse Savannah River Company.

  17. 2D hydrodynamic simulations of a variable length gas target for density down-ramp injection of electrons into a laser wakefield accelerator

    NASA Astrophysics Data System (ADS)

    Kononenko, O.; Lopes, N. C.; Cole, J. M.; Kamperidis, C.; Mangles, S. P. D.; Najmudin, Z.; Osterhoff, J.; Poder, K.; Rusby, D.; Symes, D. R.; Warwick, J.; Wood, J. C.; Palmer, C. A. J.

    2016-09-01

    In this work, two-dimensional (2D) hydrodynamic simulations of a variable length gas cell were performed using the open source fluid code OpenFOAM. The gas cell was designed to study controlled injection of electrons into a laser-driven wakefield at the Astra Gemini laser facility. The target consists of two compartments: an accelerator and an injector section connected via an aperture. A sharp transition between the peak and plateau density regions in the injector and accelerator compartments, respectively, was observed in simulations with various inlet pressures. The fluid simulations indicate that the length of the down-ramp connecting the sections depends on the aperture diameter, as does the density drop outside the entrance and the exit cones. Further studies showed, that increasing the inlet pressure leads to turbulence and strong fluctuations in density along the axial profile during target filling, and consequently, is expected to negatively impact the accelerator stability.

  18. Laser wakefield acceleration of electrons with ionization injection in a pure N{sup 5+} plasma waveguide

    SciTech Connect

    Goers, A. J.; Yoon, S. J.; Elle, J. A.; Hine, G. A.; Milchberg, H. M.

    2014-05-26

    Ionization injection-assisted laser wakefield acceleration of electrons up to 120 MeV is demonstrated in a 1.5 mm long pure helium-like nitrogen plasma waveguide. The guiding structure stabilizes the high energy electron beam pointing and reduces the beam divergence. Our results are confirmed by 3D particle-in-cell simulations.

  19. Simulations of laser-wakefield acceleration with external electron-bunch injection for REGAE experiments at DESY

    SciTech Connect

    Grebenyuk, Julia; Mehrling, Timon; Tsung, Frank S.; Floettman, Klaus; Osterhoff, Jens

    2012-12-21

    We present particle-in-cell simulations for future laser-plasma wakefield experiments with external bunch injection at the REGAE accelerator facility at DESY, Hamburg, Germany. Two effects have been studied in detail: emittance evolution of electron bunches externally injected into a wake, and longitudinal bunch compression inside the wakefield. Results show significant transverse emittance growth during the injection process, if the electron bunch is not matched to its intrinsic betatron motion inside the wakefield. This might introduce the necessity to include beam-matching sections upstream of each plasma-accelerator section with fundamental implications on the design of staged laser wakefield accelerators. When externally injected at the zero-field crossing of the laser-driven wake, the electron bunch may undergo significant compression in longitudinal direction and be accelerated simultaneously due to the gradient in the acting force. The mechanism would allow for production of single high-energy, ultra-short (on the order of one femtosecond) bunches at REGAE. The optimal conditions for maximal bunch compression are discussed in the presented studies.

  20. Analytic model of electron self-injection in a plasma wakefield accelerator in the strongly nonlinear bubble regime

    SciTech Connect

    Yi, S. A.; Khudik, V.; Siemon, C.; Shvets, G.

    2012-12-21

    Self-injection of background electrons in plasma wakefield accelerators in the highly nonlinear bubble regime is analyzed using particle-in-cell and semi-analytic modeling. It is shown that the return current in the bubble sheath layer is crucial for accurate determination of the trapped particle trajectories.

  1. Enhancement of injection and acceleration of electrons in a laser wakefield accelerator by using an argon-doped hydrogen gas jet and optically preformed plasma waveguide

    SciTech Connect

    Ho, Y.-C.; Hung, T.-S.; Chen, S.-Y.; Chou, M.-C.; Yen, C.-P.; Wang, J.; Chu, H.-H.; Lin, J.-Y.

    2011-06-15

    A systematic experimental study on injection of electrons in a gas-jet-based laser wakefield accelerator via ionization of dopant was conducted. The pump-pulse threshold energy for producing a quasi-monoenergetic electron beam was significantly reduced by doping the hydrogen gas jet with argon atoms, resulting in a much better spatial contrast of the electron beam. Furthermore, laser wakefield electron acceleration in an optically preformed plasma waveguide based on the axicon-ignitor-heater scheme was achieved. It was found that doping with argon atoms can also lower the pump-pulse threshold energy in this experimental configuration.

  2. High quality electron beam acceleration by ionization injection in laser wakefields with mid-infrared dual-color lasers

    NASA Astrophysics Data System (ADS)

    Zeng, Ming; Luo, Ji; Chen, Min; Mori, Warren B.; Sheng, Zheng-Ming; Hidding, Bernhard

    2016-06-01

    For the laser wakefield acceleration, suppression of beam energy spread while keeping sufficient charge is one of the key challenges. In order to achieve this, we propose bichromatic laser ionization injection with combined laser wavelengths of 2.4 μ m and 0.8 μ m for wakefield excitation and triggering electron injection via field ionization, respectively. A laser pulse at 2.4 μ m wavelength enables one to drive an intense acceleration structure with a relatively low laser power. To further reduce the requirement of laser power, we also propose to use carbon dioxide as the working gas medium, where carbon acts as the injection element. Our three dimensional particle-in-cell simulations show that electron beams at the GeV energy level with both low energy spreads (around 1%) and high charges (several tens of picocoulomb) can be obtained by the use of this scheme with laser peak power totaling sub-100 TW.

  3. Flow monitoring and control system for injection wells

    DOEpatents

    Corey, John C.

    1993-01-01

    A system for monitoring and controlling the injection rate of fluid by an injection well of an in-situ remediation system for treating a contaminated groundwater plume. The well is fitted with a gated insert, substantially coaxial with the injection well. A plurality of openings, some or all of which are equipped with fluid flow sensors and gates, are spaced along the insert. The gates and sensors are connected to a surface controller. The insert may extend throughout part of, or substantially the entire length of the injection well. Alternatively, the insert may comprise one or more movable modules which can be positioned wherever desired along the well. The gates are opened part-way at the start of treatment. The sensors monitor and display the flow rate of fluid passing through each opening on a controller. As treatment continues, the gates are opened to increase flow in regions of lesser flow, and closed to decrease flow in regions of greater flow, thereby approximately equalizing the amount of fluid reaching each part of the plume.

  4. Flow monitoring and control system for injection wells

    DOEpatents

    Corey, J.C.

    1993-02-16

    A system for monitoring and controlling the injection rate of fluid by an injection well of an in-situ remediation system for treating a contaminated groundwater plume. The well is fitted with a gated insert, substantially coaxial with the injection well. A plurality of openings, some or all of which are equipped with fluid flow sensors and gates, are spaced along the insert. The gates and sensors are connected to a surface controller. The insert may extend throughout part of, or substantially the entire length of the injection well. Alternatively, the insert may comprise one or more movable modules which can be positioned wherever desired along the well. The gates are opened part-way at the start of treatment. The sensors monitor and display the flow rate of fluid passing through each opening on a controller. As treatment continues, the gates are opened to increase flow in regions of lesser flow, and closed to decrease flow in regions of greater flow, thereby approximately equalizing the amount of fluid reaching each part of the plume.

  5. APPARATUS FOR CONTROL OF HIGH-ENERGY ACCELERATORS

    DOEpatents

    Heard, H.G.

    1961-10-24

    A particle beam positioning control for a synchrotron or the like is described. The control includes means for selectively impressing a sinusoidal perturbation upon the rising voltage utilized to sweep the frequency of the f-m oscillator which is conventionally coupled to the accelerating electrode of a synchrotron. The perturbation produces a variation in the normal rate of change of frequency of the accelerating voltage applied to the accelerating electrode, resulting in an expansion or contraction of the particle beam orbit diameter during the perturbation. The beam may thus be controlled such that a portion strikes a target positioned close to the expanded or contracted orbit diameter and returns to the original orbit for further acceleration to the final energy. (AEC)

  6. No Acceleration of Intervertebral Disc Degeneration after a Single Injection of Bupivacaine in Young Age Group with Follow-Up of 5 Years

    PubMed Central

    Inoue, Gen; Orita, Sumihisa; Eguchi, Yawara; Ochiai, Nobuyasu; Kishida, Shunji; Kuniyoshi, Kazuki; Nakamura, Junichi; Aoki, Yasuchika; Ishikawa, Tetsuhiro; Miyagi, Masayuki; Kamoda, Hiroto; Suzuki, Miyako; Takaso, Masashi; Toyone, Tomoaki; Kubota, Gou; Sakuma, Yoshihiro; Oikawa, Yasuhiro; Inage, Kazuhide; Sainoh, Takeshi; Takahashi, Kazuhisa

    2013-01-01

    Study Design Prospective study of changes in intervertebral disc degeneration after injection of bupivacaine. Purpose To examine whether injection of bupivacaine into human intervertebral discs accelerates their degeneration. Overview of Literature Bupivacaine is commonly used for therapy and diagnosis of discogenic low back pain. However, several in vitro studies have reported toxic effects of bupivacaine to disc cells. We sought to evaluate whether this finding is clinically relevant. Methods We selected 46 patients with low back pain who showed disc degeneration at only one level (L4-L5 or L5-S1) on magnetic resonance imaging (MRI) (discography group, n=18), discoblock group (injection of bupivacaine, n=18), and a control group, n=10). There were no significant differences in baseline characteristics across the 3 groups. The two experimental groups underwent either discography or anesthetic discoblock, respectively. All three groups were followed up 5 years after the examination. Results At 5 years follow-up, there was no significant difference in the rate of disc degeneration among the 3 groups (p>0.1). Moreover, X-ray images showed that there was no significant difference in disc height, range of motion, or translation between flex and extension position (p>0.1). Conclusions In conclusion, radiologic and MRI findings did not show acceleration of intervertebral disc degeneration at 5 years after a single injection of bupivacaine into human discs. PMID:24066217

  7. Simulations of second-order Fermi acceleration of electrons: Solving the injection problem

    SciTech Connect

    Gisler, G.R.

    1991-12-31

    The boosting of electrons from a Maxwellian distribution into a suprathermal power-law tail has long been recognized as an important bottleneck governing the subsequent acceleration of some of these electrons to relativistic energies. This is the seed or injection problem. I study this boosting process using a test-particle simulation code, following the full equations of motion of tens of thousands of electrons chosen from a thermal population as they move through general time-dependent magnetic fields. Inhomogeneities in the magnetic field are provided by finite swarms of moving current loops with Maxwellian velocity distributions and power-law distributions of loop size and dipole moment strength. Whether bulk heating or boosting occurs is found to depend on the size of the swarm thermal speed compared to the electron thermal speed. When the swarm thermal speed is comparable to the electron thermal speed the entire electron population is heated by encounters with the rapidly moving current loops, approximately preserving the Maxwellian character of the electron distribution. On the other hand, at very low swarm thermal speeds there is no bulk heating; instead one percent or fewer of the electrons are boosted into a power-law suprathermal tail with a differential energy spectral index between 1 and 2. Individual boosts of 2000 and more have been observed in samples of 50,000 electrons. Most of the strongly boosted electrons have initial energies that are well below the peak of the initial Maxwellian.

  8. Optimization of Beam Injection Into the First Accelerating Module at TTF With Cavity Dipole Mode Signals

    SciTech Connect

    Baboi, N.; Kreps, G.; Schlarb, H.; Wendt, M.; Frisch, J.; McCormick, D.; Ross, M.; Smith, T.; Napoly, O.; Paparella, R.G.; /DSM, DAPNIA, Saclay

    2006-04-10

    The TESLA Test Facility (TTF) is a user facility for intense VUV-FEL light. The facility is densely equipped with diagnostics, essential in obtaining the necessary beam parameters, in particular the low emittance. However there is no dedicated component for alignment of the beam in the accelerating modules, each containing eight superconducting cavities. Large beam offsets can lead to an increase of the beam emittance. The centering of the beam in these modules is therefore important, mostly at the low energy end. A misalignment of the first TTF module with respect to the gun axis has already been observed using cavity dipole modes. This paper presents the experimental results of the optimization of the beam injection into the first module, based on the monitoring of dipole modes through the couplers installed for wakefield damping. For this we use a spectrum analyzer together with a multiplexer. By scanning the beam position and tilt with two pairs of steerers, we can find the trajectory which minimizes the dipole modes amplitude. The impact of the beam steering in the module on the beam is discussed. A time domain setup is also being presented.

  9. FURNACE INJECTION OF ALKALINE SORBENTS FOR SULFURIC ACID CONTROL

    SciTech Connect

    Gary M. Blythe

    2001-11-06

    This document summarizes progress on Cooperative Agreement DE-FC26-99FT40718, Furnace Injection of Alkaline Sorbents for Sulfuric Acid Control, during the time period April 1, 2001 through September 30, 2001. The objective of this project is to demonstrate the use of alkaline reagents injected into the furnace of coal-fired boilers as a means of controlling sulfuric acid emissions. The coincident removal of hydrochloric acid and hydrofluoric acid is also being determined, as is the removal of arsenic, a known poison for NO{sub x} selective catalytic reduction (SCR) catalysts. EPRI, the Tennessee Valley Authority (TVA), FirstEnergy Corporation, and the Dravo Lime Company are project co-funders. URS Corporation is the prime contractor. During the current period, American Electric Power (AEP) joined the project as an additional co-funder and as a provider of a host site for testing. This is the fourth reporting period for the subject Cooperative Agreement. During this period, two long-term sorbent injection tests were conducted, one on Unit 3 at FirstEnergy's Bruce Mansfield Plant (BMP) and one on Unit 1 at AEP's Gavin Station. These tests determined the effectiveness of injecting alkaline slurries into the upper furnace of the boiler as a means of controlling sulfuric acid emissions from these units. The alkaline slurries tested included commercially available magnesium hydroxide slurry (Gavin Station), and a byproduct magnesium hydroxide slurry (both Gavin Station and BMP). The tests showed that injecting either the commercial or the byproduct magnesium hydroxide slurry could achieve up to 70 to 75% sulfuric acid removal. At BMP, the overall removal was limited by the need to maintain acceptable electrostatic precipitator (ESP) particulate control performance. At Gavin Station, the overall sulfuric acid removal was limited because the furnace injected sorbent was less effective at removing SO{sub 3} formed across the SCR system installed on the unit for NO{sub x

  10. Petawatt laser-driven wakefield accelerator: All-optical electron injection via collision of laser pulses and radiation cooling of accelerated electron bunches.

    NASA Astrophysics Data System (ADS)

    Kalmykov, Serguei; Avitzour, Yoav; Yi, S. Austin; Shvets, Gennady

    2007-11-01

    We explore an electron injection into the laser wakefield accelerator (LWFA) using nearly head-on collision of the petawatt ultrashort (˜30 fs) laser pulse (driver) with a low- amplitude laser (seed) beam of the same duration and polarization. To eliminate the threat to the main laser amplifier we consider two options: (i) a frequency-shifted seed and (ii) a seed pulse propagating at a small angle to the axis. We show that the emission of synchrotron radiation due to betatron oscillations of trapped and accelerated electrons results in significant transverse cooling of quasi- monoenergetic accelerated electrons (with energies above 1 GeV). At the same time, the energy losses due to the synchrotron emission preserve the final energy spread of the electron beam. The ``dark current'' due to the electron trapping in multiple wake buckets and the effect of beam loading (wake destruction at the instant of beams collision) are discussed.

  11. Single-hit spectroscopy of betatron X-ray spectra generated by laser wakefield acceleration using self and ionization injection

    NASA Astrophysics Data System (ADS)

    Condamine, Florian; Schumaker, Will; Kotick, Jordan; Albert, Felicie; Barbrel, Benjamin; Galtier, Eric; Granados, Eduardo; Ravasio, Alessandra; Fry, Alan; Glenzer, Siegfried

    2015-11-01

    Betatron X-ray created by laser wakefield acceleration (LWFA) are of fundamental interest in plasma physics due to their broadband X-ray spectra, compact source size and ultra short duration. In particular, the femtosecond duration of electrons bunches produced during LWFA offers the opportunity to study warm dense matter (WDM) in detail via pump/probe experiments. In this study, we used the SLAC MEC optical laser (Ti:S 800nm, 1J in 40fs) focused in a gas cell to generate betatron X-ray by using two LWFA techniques : self-injection and ionization-injection. Three different gas types (100%, 98% and 90% helium, doped with nitrogen) were investigated using a single hit detector to characterize X-ray spectra generated by the betatron source. We will compare results with self-injection and ionization-injection for different plasma conditions and several positions of the laser focal spot inside the gas cell.

  12. Readout control for high luminosity accelerators

    NASA Astrophysics Data System (ADS)

    Belusevic, R.; Nixon, G.

    1991-09-01

    In this article we discuss some aspects of data acquisition at high luminosities and offer a set of design principles concerning readout control electronics and related software. As an example we include a brief description of a data transfer and processing system for future hadron colliders, featuring a transputer-based crate controller and a set of readout cards. This is a simplified and more efficient version of our design recently published in Nuclear Instruments and Methods. [A295 (1991) 391].

  13. FURNACE INJECTION OF ALKALINE SORBENTS FOR SULFURIC ACID CONTROL

    SciTech Connect

    Gary M. Blythe

    2002-04-29

    This document summarizes progress on Cooperative Agreement DE-FC26-99FT40718, Furnace Injection of Alkaline Sorbents for Sulfuric Acid Control, during the time period October 1, 2001 through March 31, 2002. The objective of this project is to demonstrate the use of alkaline reagents injected into the furnace of coal-fired boilers as a means of controlling sulfuric acid emissions. The coincident removal of hydrochloric acid and hydrofluoric acid is also being determined, as is the removal of arsenic, a known poison for NO{sub X} selective catalytic reduction (SCR) catalysts. EPRI, the Tennessee Valley Authority (TVA), FirstEnergy Corporation, American Electric Power (AEP) and the Dravo Lime Company are project co-funders. URS Corporation is the prime contractor. This is the fifth reporting period for the subject Cooperative Agreement. During the previous (fourth) period, two long-term sorbent injection tests were conducted, one on Unit 3 at FirstEnergy's Bruce Mansfield Plant (BMP) and one on Unit 1 at AEP's Gavin Plant. Those tests determined the effectiveness of injecting alkaline slurries into the upper furnace of the boiler as a means of controlling sulfuric acid emissions from these units. The alkaline slurries tested included commercially available magnesium hydroxide slurry (Gavin Plant) and a byproduct magnesium hydroxide slurry (at both Gavin and BMP). The tests showed that injecting either the commercial or the byproduct magnesium hydroxide slurry could achieve up to 70-75% overall sulfuric acid removal. At BMP, the overall removal was limited by the need to maintain acceptable electrostatic precipitator (ESP) particulate control performance. At Gavin Plant, the overall sulfuric acid removal was limited because the furnace injected sorbent was less effective at removing SO{sub 3} formed across the SCR system installed on the unit for NO{sub X} control than at removing SO{sub 3} formed in the furnace. The SO{sub 3} removal results were presented in the

  14. Adaptive control technique for accelerators using digital signal processing

    SciTech Connect

    Eaton, L.; Jachim, S.; Natter, E.

    1987-01-01

    The use of present Digital Signal Processing (DSP) techniques can drastically reduce the residual rf amplitude and phase error in an accelerating rf cavity. Accelerator beam loading contributes greatly to this residual error, and the low-level rf field control loops cannot completely absorb the fast transient of the error. A feedforward technique using DSP is required to maintain the very stringent rf field amplitude and phase specifications. 7 refs.

  15. ISABELLE accelerator software, control system, and beam diagnostic philosophy

    SciTech Connect

    Cornacchia, M.; Humphrey, J.W.; Niederer, J.; Poole, J.H.

    1981-01-01

    The ISABELLE Project combines two large proton accelerators with two storage rings in the same facility using superconducting magnet technology. This combination leads to severe constraints on beam loss in magnets and involves complex treatment of magnetic field imperfections and correction elements. The consequent demands placed upon beam diagnostics, accelerator model programs, and the computer oriented control system are discussed in terms of an illustrative operation scenario.

  16. The processes controlling damage zone propagation induced by wellbore fluid injection

    NASA Astrophysics Data System (ADS)

    Shalev, Eyal; Lyakhovsky, Vladimir

    2013-04-01

    Induced seismicity by wellbore fluid injection is an important tool for enhancing permeability in hydrocarbon and geothermal reservoirs. We model nucleation and propagation of damage zones and seismicity patterns for two-dimensional plane strain configuration at a depth of 5 km using novel numerical software developed in the course of this study. Simulations include the coupling of poro-elastic deformation and groundwater flow with damage evolution (weakening and healing) and its effect on the elastic and hydrologic parameters. Results show that the process occurring during fluid injection can be divided into four stages. The duration of each stage depends on the hydrological and mechanical parameters. Initially, fluid flows into the rock with no seismic events (5 to 20 hr). At this stage, damage increases from 0 to 1 creating two sets of conjugate zones (four narrow damage zones). Thereafter, the occurrence of seismic events and faulting begins and accelerates for the next 20 to 70 hr. At the initial part of this stage, two of the damage zones create stress shadows on the other two damage zones that stop progressing. The velocity of the advancing damage is limited only by the rock parameters controlling damage evolution. At the third stage, which lasts for the following 20-30 hr, damage acceleration decreases because fluid transport becomes a limiting factor as the damage zones are too long to efficiently transfer the pressure from the well to the tip of the damage zones. Finally, the damage decelerates and even stops in some cases. The propagation of damage is controlled and limited by fluid transport from the injection well to the tip of the damage zones because fluid transport does not keep up with the dilatancy of the damage zones. The time and distance of propagation depend on the damage-permeability coupling and the remote shear stress. Higher remote shear stress causes shorter initial periods of no seismicity; strong damage-permeability coupling causes

  17. Control over Drug Acquisition, Preparation, and Injection: Implications for HIV and HCV Risk among Young Female Injection Drug Users

    PubMed Central

    Wagner, Karla D.; Jackson Bloom, Jennifer; Hathazi, Susan Dodi; Sanders, Bill; Lankenau, Stephen E.

    2013-01-01

    Young female injection drug users (IDUs) are at risk for HIV/HCV, and initiating the use of a new drug may confer additional and unexpected risks. While gender differences in the social context of injection drug use have been identified, it is unknown whether those differences persist during the initiation of a new drug. This mixed-methods study examined the accounts of 30 young female IDUs in Los Angeles, CA, USA from 2004 to 2006, who described the social context of initiating injection drug use and initiating ketamine injection. The analysis aimed to understand how the social context of young women's injection events contributes to HIV/HCV risk. Women's initiation into ketamine injection occurred approximately 2 years after their first injection of any drug. Over that time, women experienced changes in some aspects of the social context of drug injection, including the size and composition of the using group. A significant proportion of women described injection events characterized by a lack of control over the acquisition, preparation, and injection of drugs, as well as reliance on friends and sexual partners. Findings suggest that lack of control over drug acquisition, preparation, and injection may elevate women's risk; these phenomena should be considered as a behavioral risk factor when designing interventions. PMID:24364027

  18. Ionization injection effects in x-ray spectra generated by betatron oscillations in a laser wakefield accelerator

    NASA Astrophysics Data System (ADS)

    Behm, K. T.; Zhao, T. Z.; Cole, J. M.; Maksimchuk, A.; Mangles, S. P. D.; Nees, J.; Wood, J. C.; Yanovsky, V.; Krushelnick, K.; Thomas, A. G. R.

    2016-05-01

    Single photon counting techniques were used with an x-ray CCD camera to measure features of synchrotron-like x-ray spectra generated by betatron oscillations of electrons in a laser wakefield accelerator (LWFA) with different injection techniques. Measurements were made using the Hercules laser system at the University of Michigan. With a single stage gas cell, we demonstrate that pure helium gas in our wakefield accelerator will produce spectra with higher critical energies than when helium mixed with nitrogen is used. This result was not evident when a two stage gas cell was used.

  19. FURNACE INJECTION OF ALKALINE SORBENTS FOR SULFURIC ACID CONTROL

    SciTech Connect

    Gary M. Blythe

    2003-10-01

    This document summarizes progress on Cooperative Agreement DE-FC26-99FT40718, Furnace Injection of Alkaline Sorbents for Sulfuric Acid Control, during the time period April 1, 2003 through September, 2003. The objective of this project is to demonstrate the use of alkaline reagents injected into the furnace of coal-fired boilers as a means of controlling sulfuric acid emissions. The coincident removal of hydrochloric acid and hydrofluoric acid is also being determined, as is the removal of arsenic, a known poison for NO{sub x} selective catalytic reduction (SCR) catalysts. EPRI, the Tennessee Valley Authority (TVA), FirstEnergy Corporation, American Electric Power (AEP) and the Dravo Lime Company are project co-funders. URS Group is the prime contractor. This is the eighth reporting period for the subject Cooperative Agreement. During previous reporting periods, two long-term sorbent injection tests were conducted, one on Unit 3 at FirstEnergy's Bruce Mansfield Plant (BMP) and one on Unit 1 at AEP's Gavin Plant. Those tests determined the effectiveness of injecting alkaline slurries into the upper furnace of the boiler as a means of controlling sulfuric acid emissions from these units. The alkaline slurries tested included commercially available magnesium hydroxide slurry (Gavin Plant), and a byproduct magnesium hydroxide slurry (both Gavin Plant and BMP). The tests showed that injecting either the commercial or the byproduct magnesium hydroxide slurry could achieve up to 70-75% overall sulfuric acid removal. At BMP, the overall removal was limited by the need to maintain acceptable electrostatic precipitator (ESP) particulate control performance. At Gavin Plant, the overall sulfuric acid removal was limited because the furnace injected sorbent was less effective at removing SO{sub 3} formed across the SCR system installed on the unit for NO{sub x} control than at removing SO{sub 3} formed in the furnace. The SO{sub 3} removal results were presented in the semi

  20. FURNACE INJECTION OF ALKALINE SORBENTS FOR SULFURIC ACID CONTROL

    SciTech Connect

    Gary M. Blythe

    2003-06-01

    This document summarizes progress on Cooperative Agreement DE-FC26-99FT40718, Furnace Injection of Alkaline Sorbents for Sulfuric Acid Control, during the time period October 1, 2002 through March 31, 2003. The objective of this project is to demonstrate the use of alkaline reagents injected into the furnace of coal-fired boilers as a means of controlling sulfuric acid emissions. The coincident removal of hydrochloric acid and hydrofluoric acid is also being determined, as is the removal of arsenic, a known poison for NO{sub x} selective catalytic reduction (SCR) catalysts. EPRI, the Tennessee Valley Authority (TVA), FirstEnergy Corporation, American Electric Power (AEP) and the Dravo Lime Company are project co-funders. URS Group is the prime contractor. This is the seventh reporting period for the subject Cooperative Agreement. During previous reporting periods, two long-term sorbent injection tests were conducted, one on Unit 3 at FirstEnergy's Bruce Mansfield Plant (BMP) and one on Unit 1 at AEP's Gavin Plant. Those tests determined the effectiveness of injecting alkaline slurries into the upper furnace of the boiler as a means of controlling sulfuric acid emissions from these units. The alkaline slurries tested included commercially available magnesium hydroxide slurry (Gavin Plant), and a byproduct magnesium hydroxide slurry (both Gavin Plant and BMP). The tests showed that injecting either the commercial or the byproduct magnesium hydroxide slurry could achieve up to 70-75% overall sulfuric acid removal. At BMP, the overall removal was limited by the need to maintain acceptable electrostatic precipitator (ESP) particulate control performance. At Gavin Plant, the overall sulfuric acid removal was limited because the furnace injected sorbent was less effective at removing SO{sub 3} formed across the SCR system installed on the unit for NO{sub x} control than at removing SO{sub 3} formed in the furnace. The SO3 removal results were presented in the semi

  1. Atmosphere control during debinding of powder injection molded parts

    NASA Astrophysics Data System (ADS)

    Moore, J. A.; Jarding, B. P.; Lograsso, B. K.; Anderson, I. E.

    1995-06-01

    Atmosphere control during debinding of powder injection molded (PIM) parts is an important parameter to consider. Experimental results have shown that a stagnant atmosphere containing volatiles evolved during debinding can cause slumping of the green samples. Removal of volatiles from the sample zone aids debinding and can reduce cycle times and improve sample quality. Residual carbon and oxygen can be controlled during debinding by adjusting the atmosphere composition. This paper presents the results of PIM 70 vol% spherical copper powder and 30 vol% binder. Debinding atmospheres were altered to determine the effect of debinding on the green body and the sintered sample.

  2. Controllability in Multi-Stage Laser Ion Acceleration

    NASA Astrophysics Data System (ADS)

    Kawata, S.; Kamiyama, D.; Ohtake, Y.; Barada, D.; Ma, Y. Y.; Kong, Q.; Wang, P. X.; Gu, Y. J.; Li, X. F.; Yu, Q.

    2015-11-01

    The present paper shows a concept for a future laser ion accelerator, which should have an ion source, ion collimators, ion beam bunchers and ion post acceleration devices. Based on the laser ion accelerator components, the ion particle energy and the ion energy spectrum are controlled, and a future compact laser ion accelerator would be designed for ion cancer therapy or for ion material treatment. In this study each component is designed to control the ion beam quality. The energy efficiency from the laser to ions is improved by using a solid target with a fine sub-wavelength structure or a near-critical density gas plasma. The ion beam collimation is performed by holes behind the solid target or a multi-layered solid target. The control of the ion energy spectrum and the ion particle energy, and the ion beam bunching are successfully realized by a multi-stage laser-target interaction. A combination of each component provides a high controllability of the ion beam quality to meet variable requirements in various purposes in the laser ion accelerator. The work was partly supported by MEXT, JSPS, ASHULA project/ ILE, Osaka University, CORE (Center for Optical Research and Education, Utsunomiya University, Japan), Fudan University and CDI (Creative Dept. for Innovation) in CCRD, Utsunomiya University.

  3. Apparatus and method for controlling the secondary injection of fuel

    DOEpatents

    Martin, Scott M.; Cai, Weidong; Harris, Jr., Arthur J.

    2013-03-05

    A combustor (28) for a gas turbine engine is provided comprising a primary combustion chamber (30) for combusting a first fuel to form a combustion flow stream (50) and a transition piece (32) located downstream from the primary combustion chamber (30). The transition piece (32) comprises a plurality of injectors (66) located around a circumference of the transition piece (32) for injecting a second fuel into the combustion flow stream (50). The injectors (66) are effective to create a radial temperature profile (74) at an exit (58) of the transition piece (32) having a reduced coefficient of variation relative to a radial temperature profile (64) at an inlet (54) of the transition piece (32). Methods for controlling the temperature profile of a secondary injection are also provided.

  4. Caudal epidural steroid injection: a randomized controlled trial

    PubMed Central

    Murakibhavi, V. G.; Khemka, Aditya G.

    2011-01-01

    Study design: Prospective study. Study rationale: A recurrent phenomenon, the lifetime prevalence of low back pain has been reported as 54%–80%, while annual prevalence ranges from 15%–45%.1 It is also associated with enormous economic, societal, and health impact.2 India, being a developing country, has its problem compounded by the occupational compulsions in parts of the rural areas.3 For some interventional therapies, like epidural steroid injections, utilization rates have increased dramatically.4,5,6,7,8,9 They have become one of the most commonly performed interventions in the United States for low back pain with radiculopathy.10 Clinical question: Multiple systematic reviews,11 a meta-analysis,12 several guidelines,13 health technology assessments by insurers, and local medical review policies and coverage decisions have been published. However, controversy continues regarding the effectiveness of epidural steroid injections. In addition three types of epidurals, namely interlaminar, transforaminal, and caudal, with variable results complicate the picture for practice of interventional pain management. The underlying mechanism of action of epidurally administered steroid and local anesthetic injections is still not well understood and compounds the problem.14 Objective: To evaluate and update the effects of caudal epidural injection in the management of chronic low back pain and sciatica. Final Class of evidence-treatment Yes Study design:  RCT •  Cohort  Case control  Case series Methods  Concealed allocation (RCT) •  Intention to treat (RCT) •  Blinded/independent evaluation of primary outcome •  F/U ≥ 85% •  Adequate sample size • Control for confounding Overall class of evidence II The definiton of the different classes of evidence is available here. PMID:23230402

  5. Injection and acceleration of quasimonoenergetic relativistic electron beams using density gradients at the edges of a plasma channel

    SciTech Connect

    Faure, J.; Rechatin, C.; Lundh, O.; Ammoura, L.; Malka, V.

    2010-08-15

    The injection of quasimonoenergetic electron beams into a laser wakefield accelerator is demonstrated experimentally using density gradients at the edges of a plasma channel. In the experiment, two laser pulses are used; the main laser pulse drives a wakefield, while a second countercrossing laser beam produces a plasma whose expansion creates a channel with significant density gradients. Local injection of electrons in the wakefield is triggered by wave breaking in the density ramp. The injection is localized spatially and leads to the generation of collimated and narrow energy spread relativistic electron beams at the 100 MeV level, with charges in the range of 20-100 pC. The stability of this injection process is compared to the stability of the colliding pulse injection process and is found to be inferior for our experimental conditions. On the other hand, it is found that as the electron beam divergence is smaller in the case of gradient injection, the transverse emittance might be better.

  6. A bremsstrahlung gamma-ray source based on stable ionization injection of electrons into a laser wakefield accelerator

    NASA Astrophysics Data System (ADS)

    Döpp, A.; Guillaume, E.; Thaury, C.; Lifschitz, A.; Sylla, F.; Goddet, J.-P.; Tafzi, A.; Iaquanello, G.; Lefrou, T.; Rousseau, P.; Conejero, E.; Ruiz, C.; Ta Phuoc, K.; Malka, V.

    2016-09-01

    Laser wakefield acceleration permits the generation of ultra-short, high-brightness relativistic electron beams on a millimeter scale. While those features are of interest for many applications, the source remains constraint by the poor stability of the electron injection process. Here we present results on injection and acceleration of electrons in pure nitrogen and argon. We observe stable, continuous ionization-induced injection of electrons into the wakefield for laser powers exceeding a threshold of 7 TW. The beam charge scales approximately with the laser energy and is limited by beam loading. For 40 TW laser pulses we measure a maximum charge of almost 1 nC per shot, originating mostly from electrons of less than 10 MeV energy. The relatively low energy, the high charge and its stability make this source well-suited for applications such as non-destructive testing. Hence, we demonstrate the production of energetic radiation via bremsstrahlung conversion at 1 Hz repetition rate. In accordance with GEANT4 Monte-Carlo simulations, we measure a γ-ray source size of less than 100 μm for a 0.5 mm tantalum converter placed at 2 mm from the accelerator exit. Furthermore we present radiographs of image quality indicators.

  7. Acceleration and torque feedback for robotic control - Experimental results

    NASA Technical Reports Server (NTRS)

    Mclnroy, John E.; Saridis, George N.

    1990-01-01

    Gross motion control of robotic manipulators typically requires significant on-line computations to compensate for nonlinear dynamics due to gravity, Coriolis, centripetal, and friction nonlinearities. One controller proposed by Luo and Saridis avoids these computations by feeding back joint acceleration and torque. This study implements the controller on a Puma 600 robotic manipulator. Joint acceleration measurement is obtained by measuring linear accelerations of each joint, and deriving a computationally efficient transformation from the linear measurements to the angular accelerations. Torque feedback is obtained by using the previous torque sent to the joints. The implementation has stability problems on the Puma 600 due to the extremely high gains inherent in the feedback structure. Since these high gains excite frequency modes in the Puma 600, the algorithm is modified to decrease the gain inherent in the feedback structure. The resulting compensator is stable and insensitive to high frequency unmodeled dynamics. Moreover, a second compensator is proposed which uses acceleration and torque feedback, but still allows nonlinear terms to be fed forward. Thus, by feeding the increment in the easily calculated gravity terms forward, improved responses are obtained. Both proposed compensators are implemented, and the real time results are compared to those obtained with the computed torque algorithm.

  8. A count rate based contamination control standard for electron accelerators

    SciTech Connect

    May, R.T.; Schwahn, S.O.

    1996-12-31

    Accelerators of sufficient energy and particle fluence can produce radioactivity as an unwanted byproduct. The radioactivity is typically imbedded in structural materials but may also be removable from surfaces. Many of these radionuclides decay by positron emission or electron capture; they often have long half lives and produce photons of low energy and yield making detection by standard devices difficult. The contamination control limit used throughout the US nuclear industry and the Department of Energy is 1,000 disintegrations per minute. This limit is based on the detection threshold of pancake type Geiger-Mueller probes for radionuclides of relatively high radiotoxicity, such as cobalt-60. Several radionuclides of concern at a high energy electron accelerator are compared in terms of radiotoxicity with radionuclides commonly found in the nuclear industry. Based on this comparison, a count-rate based contamination control limit and associated measurement strategy is proposed which provides adequate detection of contamination at accelerators without an increase in risk.

  9. Implementation of the beamline controls at the Florence accelerator laboratory

    NASA Astrophysics Data System (ADS)

    Carraresi, L.; Mirto, F. A.

    2008-05-01

    The new Tandetron accelerator in Florence, with many different beamlines, has required a new organization of all the control signals of the used equipment (slow control). We present our solution, which allows us the control of all the employed instruments simultaneously from a number of different workplaces. All of our equipment has been designed to be Ethernet based and this is the key to accomplish two very important requirements: simultaneous remote control from many computers and electrical isolation to achieve a lower noise level. The control of the instruments requires only one Ethernet network and no particular interfaces or drivers on the computers.

  10. Cost and performance of activated carbon injection for mercury control

    SciTech Connect

    2006-08-15

    Activated carbon injection (ACI) is one technology being developed to absorb mercury from mercury emitted from coal-fired power plants. In 2003/04, the USDOE and NETL selected 14 projects to test and evaluate mercury control technologies. While field testing is still ongoing, DOE/NETL recently completed an economic analysis of mercury control for six test sites spanning three ACI variations - conventional powdered activated carbon (PAC), brominated PAC and conventional PAC combined with a sorbent enhancement additive (SEA) applied to the coal. To evaluate the progress of the field testing program and discern the performance of ACI, a data adjustment methodology was developed to account for baseline methane capture. This data were used to perform economic analyses to achieve low, mid and high levels of mercury control. The costs are given in the article. Full details are available on the DOE/NETL website, www.netl.doe.gov. 2 figs., 1 photo.

  11. Electron injection for direct acceleration to multi-GeV energy by a Gaussian laser field under the influence of axial magnetic field

    NASA Astrophysics Data System (ADS)

    Ghotra, Harjit Singh; Kant, Niti

    2016-05-01

    Electron injected in the path of a circularly polarized Gaussian laser beam under the influence of an external axial magnetic field is shown to be accelerated with a several GeV of energy in vacuum. A small angle of injection δ with 0 ∘ < δ < 20 ∘ for a sideway injection of electron about the axis of propagation of laser pulse is suggested for better trapping of electron in laser field and stronger betatron resonance under the influence of axial magnetic field. Such an optimized electron injection with axial magnetic field maximizes the acceleration gradient and electron energy gain with low electron scattering.

  12. Survey of Botulinum Toxin Injections in Anticoagulated Patients: Korean Physiatrists' Preference in Controlling Anticoagulation Profile Prior to Intramuscular Injection

    PubMed Central

    Jang, Yongjun; Park, Geun-Young; Park, Jihye; Choi, Asayeon; Kim, Soo Yeon; Boulias, Chris; Phadke, Chetan P.; Ismail, Farooq

    2016-01-01

    Objective To evaluate Korean physiatrists' practice of performing intramuscular botulinum toxin injection in anticoagulated patients and to assess their preference in controlling the bleeding risk before injection. Methods As part of an international collaboration survey study, a questionnaire survey was administered to 100 Korean physiatrists. Physiatrists were asked about their level of experience with botulinum toxin injection, the safe international normalized ratio range in anticoagulated patients undergoing injection, their tendency for injecting into deep muscles, and their experience of bleeding complications. Results International normalized ratio <2.0 was perceived as an ideal range for performing Botulinum toxin injection by 41% of the respondents. Thirty-six respondents replied that the international normalized ratio should be lowered to sub-therapeutic levels before injection, and 18% of the respondents reported that anticoagulants should be intentionally withheld and discontinued prior to injection. In addition, 20%–30% of the respondents answered that they were uncertain whether they should perform the injection regardless of the international normalized ratio values. About 69% of the respondents replied that they did have any standardized protocols for performing botulinum toxin injection in patients using anticoagulants. Only 1 physiatrist replied that he had encountered a case of compartment syndrome. Conclusion In accordance with the lack of consensus in performing intramuscular botulinum toxin injection in anticoagulated patients, our survey shows a wide range of practices among many Korean physiatrists; they tend to avoid botulinum toxin injection in anticoagulated patients and are uncertain about how to approach these patients. The results of this study emphasize the need for formulating a proper international consensus on botulinum toxin injection management in anticoagulated patients. PMID:27152278

  13. Tailoring the laser pulse shape to improve the quality of the self-injected electron beam in laser wakefield acceleration

    SciTech Connect

    Upadhyay, Ajay K.; Samant, Sushil A.; Krishnagopal, S.

    2013-01-15

    In laser wakefield acceleration, tailoring the shape of the laser pulse is one way of influencing the laser-plasma interaction and, therefore, of improving the quality of the self-injected electron beam in the bubble regime. Using three-dimensional particle-in-cell simulations, the evolution dynamics of the laser pulse and the quality of the self-injected beam, for a Gaussian pulse, a positive skew pulse (i.e., one with sharp rise and slow fall), and a negative skew pulse (i.e., one with a slow rise and sharp fall) are studied. It is observed that with a negative skew laser pulse there is a substantial improvement in the emittance (by around a factor of two), and a modest improvement in the energy-spread, compared to Gaussian as well as positive skew pulses. However, the injected charge is less in the negative skew pulse compared to the other two. It is also found that there is an optimal propagation distance that gives the best beam quality; beyond this distance, though the energy increases, the beam quality deteriorates, but this deterioration is least for the negative skew pulse. Thus, the negative skew pulse gives an improvement in terms of beam quality (emittance and energy spread) over what one can get with a Gaussian or positive skew pulse. In part, this is because of the lesser injected charge, and the strong suppression of continuous injection for the negative skew pulse.

  14. Towards MRI-guided linear accelerator control: gating on an MRI accelerator

    NASA Astrophysics Data System (ADS)

    Crijns, S. P. M.; Kok, J. G. M.; Lagendijk, J. J. W.; Raaymakers, B. W.

    2011-08-01

    To boost the possibilities of image guidance in radiotherapy by providing images with superior soft-tissue contrast during treatment, we pursue diagnostic quality MRI functionality integrated with a linear accelerator. Large respiration-induced semi-periodic target excursions hamper treatment of cancer of the abdominal organs. Methods to compensate in real time for such motion are gating and tracking. These strategies are most effective in cases where anatomic motion can be visualized directly, which supports the use of an integrated MRI accelerator. We establish here an infrastructure needed to realize gated radiation delivery based on MR feedback and demonstrate its potential as a first step towards more advanced image guidance techniques. The position of a phantom subjected to one-dimensional periodic translation is tracked with the MR scanner. Real-time communication with the MR scanner and control of the radiation beam are established. Based on the time-resolved position of the phantom, gated radiation delivery to the phantom is realized. Dose distributions for dynamic delivery conditions with varying gating windows are recorded on gafchromic film. The similarity between dynamically and statically obtained dose profiles gradually increases as the gating window is decreased. With gating windows of 5 mm, we obtain sharp dose profiles. We validate our gating implementation by comparing measured dose profiles to theoretical profiles calculated using the knowledge of the imposed motion pattern. Excellent correspondence is observed. At the same time, we show that real-time on-line reconstruction of the accumulated dose can be performed using time-resolved target position information. This facilitates plan adaptation not only on a fraction-to-fraction scale but also during one fraction, which is especially valuable in highly accelerated treatment strategies. With the currently established framework and upcoming improvements to our prototype-integrated MRI accelerator

  15. Electron-beam manipulation techniques in the SINBAD Linac for external injection in plasma wake-field acceleration

    NASA Astrophysics Data System (ADS)

    Marchetti, B.; Assmann, R.; Behrens, C.; Brinkmann, R.; Dorda, U.; Floettmann, K.; Hartl, I.; Huening, M.; Nie, Y.; Schlarb, H.; Zhu, J.

    2016-09-01

    The SINBAD facility (Short and INnovative Bunches and Accelerators at Desy) is foreseen to host various experiments in the field of production of ultra-short electron bunches and novel high gradient acceleration techniques. Besides studying novel acceleration techniques aiming to produce high brightness short electron bunches, the ARD group at DESY is working on the design of a conventional RF accelerator that will allow the production of low charge (0.5 pC - few pC) ultra-short electron bunches (having full width half maximum, FWHM, length ≤ 1 fs - few fs). The setup will allow the direct experimental comparison of the performance achievable by using different compression techniques (velocity bunching, magnetic compression, hybrid compression schemes). At a later stage the SINBAD linac will be used to inject such electron bunches into a laser driven Plasma Wakefield Accelerator, which imposes strong requirements on parameters such as the arrival time jitter and the pointing stability of the beam. In this paper we review the compression techniques that are foreseen at SINBAD and we underline the differences in terms of peak current, beam quality and arrival time stability.

  16. Quick setup of unit test for accelerator controls system

    SciTech Connect

    Fu, W.; D'Ottavio, T.; Gassner, D.; Nemesure, S.; Morris, J.

    2011-03-28

    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.

  17. An accelerator controls network designed for reliability and flexibility

    SciTech Connect

    McDowell, W. P.; Sidorowicz, K. V.

    1997-12-02

    The APS accelerator control system is a typical modern system based on the standard control system model, which consists of operator interfaces to a network and computer-controlled interfaces to hardware. The network provides a generalized communication path between the host computers, operator workstations, input/output crates, and other hardware that comprise the control system. The network is an integral part of all modern control systems and network performance will determine many characteristics of a control system. This paper describes the methods used to provide redundancy for various network system components as well as methods used to provide comprehensive monitoring of this network. The effect of archiving tens of thousands of data points on a regular basis and the effect on the controls network will be discussed. Metrics are provided on the performance of the system under various conditions.

  18. An RF photogun for external injection of electrons in a laser wakefield accelerator

    NASA Astrophysics Data System (ADS)

    Stragier, Xavier F. D.; van der Geer, Bas; van der Wiel, Marnix J.; Luiten, Jom; Brussaard, Seth

    2011-05-01

    It has been found that more intense proton beams are generated from plastic foils than metal foils irradiated by an ultraintense laser pulse. The acceleration model, ARIE (Acceleration by a Resistively Induced Electric field) accounts for the experimental observations from plastic foils compared with metal foils. Proton beams on foil thickness and laser prepulse have been observed, which is also well described by the ARIE model. An experiment with an aluminum-coated plastic target strongly suggests that front side acceleration is a dominant acceleration process in plastic targets. We also suggest that a vacuum-sandwiched double layer target could effectively enhance the laser contrast ratio, which was investigated in the combination of a two-dimensional hydro code and a two-dimensional PIC (Particle-In-Cell) code.

  19. A Digital Self Excited Loop for Accelerating Cavity Field Control

    SciTech Connect

    Curt Hovater; Trent Allison; Jean Delayen; John Musson; Tomasz Plawski

    2007-06-22

    We have developed a digital process that emulates an analog oscillator and ultimately a self excited loop (SEL) for field control. The SEL, in its analog form, has been used for many years for accelerating cavity field control. In essence the SEL uses the cavity as a resonant circuit -- much like a resonant (tank) circuit is used to build an oscillator. An oscillating resonant circuit can be forced to oscillate at different, but close, frequencies to resonance by applying a phase shift in the feedback path. This allows the circuit to be phased-locked to a master reference, which is crucial for multiple cavity accelerators. For phase and amplitude control the SEL must be forced to the master reference frequency, and feedback provided for in both dimensions. The novelty of this design is in the way digital signal processing (DSP) is structured to emulate an analog system. While the digital signal processing elements are not new, to our knowledge this is the first time that the digital SEL concept has been designed and demonstrated. This paper reports on the progress of the design and implementation of the digital SEL for field control of superconducting accelerating cavities.

  20. Rapid control of mold temperature during injection molding process

    NASA Astrophysics Data System (ADS)

    Liparoti, Sara; Hunag, Tsang Min; Sorrentino, Andrea; Titomanlio, Giuseppe; Cakmak, Mukerrem

    2015-05-01

    The control of mold surface temperature is an important factor that determines surface morphology and its dimension in thickness direction. It can also affect the frozen molecular orientation and the mold surface replicability in injection molded products. In this work, thin thermally active films were used to quickly control the mold surface temperature. In particular, an active high electrical conductivity carbon black loaded polyimide composites sandwiched between two insulating thin polymeric layers was used to condition the mold surface. By controlling the heating time, it was possible to control precisely the temporal variation of the mold temperature surface during the entire cycle. The surface heating rate was about 40°C/s and upon contact with the polymer the surface temperature decreased back to 40°C within about 5 s; the overall cycle time increased only slightly. The effect on cross section sample morphology of samples of iPP were analyzed and discussed on the basis of the recorded temperature evolution.

  1. Rapid control of mold temperature during injection molding process

    SciTech Connect

    Liparoti, Sara; Titomanlio, Giuseppe; Hunag, Tsang Min; Cakmak, Mukerrem; Sorrentino, Andrea

    2015-05-22

    The control of mold surface temperature is an important factor that determines surface morphology and its dimension in thickness direction. It can also affect the frozen molecular orientation and the mold surface replicability in injection molded products. In this work, thin thermally active films were used to quickly control the mold surface temperature. In particular, an active high electrical conductivity carbon black loaded polyimide composites sandwiched between two insulating thin polymeric layers was used to condition the mold surface. By controlling the heating time, it was possible to control precisely the temporal variation of the mold temperature surface during the entire cycle. The surface heating rate was about 40°C/s and upon contact with the polymer the surface temperature decreased back to 40°C within about 5 s; the overall cycle time increased only slightly. The effect on cross section sample morphology of samples of iPP were analyzed and discussed on the basis of the recorded temperature evolution.

  2. 76 FR 42125 - Underground Injection Control Program; Hazardous Waste Injection Restrictions; Petition for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-18

    ... Protection Division, Source Water Protection Branch (6WQ-S), 1445 Ross Avenue, Dallas, Texas 75202- 2733. FOR... Company for one Class I injection well located at Borger, Texas. The company has adequately demonstrated... exemption, into Class I hazardous waste injection well No. WDW-325 at the Borger Texas facility,...

  3. 76 FR 36129 - Underground Injection Control Program; Hazardous Waste Injection Restrictions; Petition for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-21

    ..., Texas 75202- 2733. FOR FURTHER INFORMATION CONTACT: Philip Dellinger, Chief Ground Water/ UIC Section... Environmental Services Company for two Class I injection wells located at Pasadena, Texas. The company has..., into Class I hazardous waste injection wells No. WDW- 397 and WDW-398 at the Agrifos Pasadena...

  4. Embedded computer controlled premixing inline injection system for air-assisted variable-rate sprayers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Improvements to reduce chemical waste and environmental pollution for variable-rate sprayers used in orchards and ornamental nurseries require inline injection techniques. A microprocessor controlled premixing inline injection system implementing a ceramic piston chemical metering pump and two small...

  5. Accelerated Hepatitis B Vaccine Schedule among Drug Users – A Randomized Controlled Trial

    PubMed Central

    Hwang, Lu-Yu; Grimes, Carolyn Z.; Tran, Thanh Quoc; Clark, April; Xia, Rui; Lai, Dejian; Troisi, Catherine; Williams, Mark

    2010-01-01

    Background Hepatitis B vaccine provides a model for improving uptake and completion of multi-dose vaccinations in the drug-using community. Methods DASH project conducted randomized controlled trial among not-in-treatment current drug users in two urban neighborhoods. Neighborhoods were cluster-randomized to receive a standard (HIV information) or enhanced (HBV vaccine acceptance/adherence) behavioral intervention; participants within clusters were randomized to a standard (0, 1, 6 mo) or accelerated (0, 1, 2 mo) vaccination schedule. Outcomes were completion of three-dose vaccine and HBV seroprotection. Results Of those screening negative for HIV/HBV, 77% accepted HB vaccination and 75% of those received all 3 doses. Injecting drug users (IDUs) on the accelerated schedule were significantly more likely to receive 3 doses (76%) than those on the standard schedule (66%, p=.04), although for drug users as a whole the adherence was 77% and 73%. No difference in adherence was observed between behavioral intervention groups. Predictors of adherence were older age, African American race, stable housing, and alcohol use. Cumulative HBV seroprotection (≥10 mIU/mL) was gained by 12 months by 65% of those completing. Seroprotection at 6 months was greater for the accelerated schedule group. Conclusions The accelerated vaccine schedule improves hepatitis B vaccination adherence among IDU. PMID:20936979

  6. Accelerated wound healing by injectable microporous gel scaffolds assembled from annealed building blocks

    NASA Astrophysics Data System (ADS)

    Griffin, Donald R.; Weaver, Westbrook M.; Scumpia, Philip O.; di Carlo, Dino; Segura, Tatiana

    2015-07-01

    Injectable hydrogels can provide a scaffold for in situ tissue regrowth and regeneration, yet gel degradation before tissue reformation limits the gels' ability to provide physical support. Here, we show that this shortcoming can be circumvented through an injectable, interconnected microporous gel scaffold assembled from annealed microgel building blocks whose chemical and physical properties can be tailored by microfluidic fabrication. In vitro, cells incorporated during scaffold formation proliferated and formed extensive three-dimensional networks within 48 h. In vivo, the scaffolds facilitated cell migration that resulted in rapid cutaneous-tissue regeneration and tissue-structure formation within five days. The combination of microporosity and injectability of these annealed gel scaffolds should enable novel routes to tissue regeneration and formation in vivo.

  7. Lessons learned on the Ground Test Accelerator control system

    SciTech Connect

    Kozubal, A.J.; Weiss, R.E.

    1994-09-01

    When we initiated the control system design for the Ground Test Accelerator (GTA), we envisioned a system that would be flexible enough to handle the changing requirements of an experimental project. This control system would use a developers` toolkit to reduce the cost and time to develop applications for GTA, and through the use of open standards, the system would accommodate unforeseen requirements as they arose. Furthermore, we would attempt to demonstrate on GTA a level of automation far beyond that achieved by existing accelerator control systems. How well did we achieve these goals? What were the stumbling blocks to deploying the control system, and what assumptions did we make about requirements that turned out to be incorrect? In this paper we look at the process of developing a control system that evolved into what is now the ``Experimental Physics and Industrial Control System`` (EPICS). Also, we assess the impact of this system on the GTA project, as well as the impact of GTA on EPICS. The lessons learned on GTA will be valuable for future projects.

  8. Device Configuration Handler for Accelerator Control Applications at Jefferson Lab

    SciTech Connect

    Matt Bickley; P. Chevtsov; T. Larrieu

    2003-10-01

    The accelerator control system at Jefferson Lab uses hundreds of physical devices with such popular instrument bus interfaces as Industry Pack (IPAC), GPIB, RS-232, etc. To properly handle all these components, control computers (IOCs) must be provided with the correct information about the unique memory addresses of the used interface cards, interrupt numbers (if any), data communication channels and protocols. In these conditions, the registration of a new control device in the control system is not an easy task for software developers. Because the device configuration is distributed, it requires the detailed knowledge about not only the new device but also the configuration of all other devices on the existing system. A configuration handler implemented at Jefferson Lab centralizes the information about all control devices making their registration user-friendly and very easy to use. It consists of a device driver framework and the device registration software developed on the basis of ORACLE database and freely available scripting tools (perl, php).

  9. Precision vector control of a superconducting RF cavity driven by an injection locked magnetron

    DOE PAGESBeta

    Chase, Brian; Pasquinelli, Ralph; Cullerton, Ed; Varghese, Philip

    2015-03-01

    The technique presented in this paper enables the regulation of both radio frequency amplitude and phase in narrow band devices such as a Superconducting RF (SRF) cavity driven by constant power output devices i.e. magnetrons [1]. The ability to use low cost high efficiency magnetrons for accelerator RF power systems, with tight vector regulation, presents a substantial cost savings in both construction and operating costs - compared to current RF power system technology. An operating CW system at 2.45 GHz has been experimentally developed. Vector control of an injection locked magnetron has been extensively tested and characterized with a SRFmore » cavity as the load. Amplitude dynamic range of 30 dB, amplitude stability of 0.3% r.m.s, and phase stability of 0.26 degrees r.m.s. has been demonstrated.« less

  10. Precision vector control of a superconducting RF cavity driven by an injection locked magnetron

    SciTech Connect

    Chase, Brian; Pasquinelli, Ralph; Cullerton, Ed; Varghese, Philip

    2015-03-01

    The technique presented in this paper enables the regulation of both radio frequency amplitude and phase in narrow band devices such as a Superconducting RF (SRF) cavity driven by constant power output devices i.e. magnetrons [1]. The ability to use low cost high efficiency magnetrons for accelerator RF power systems, with tight vector regulation, presents a substantial cost savings in both construction and operating costs - compared to current RF power system technology. An operating CW system at 2.45 GHz has been experimentally developed. Vector control of an injection locked magnetron has been extensively tested and characterized with a SRF cavity as the load. Amplitude dynamic range of 30 dB, amplitude stability of 0.3% r.m.s, and phase stability of 0.26 degrees r.m.s. has been demonstrated.

  11. Numerical investigation of closed-loop control for Hall accelerators

    SciTech Connect

    Barral, S.; Miedzik, J.

    2011-01-01

    Low frequency discharge current oscillations in Hall accelerators are conventionally damped with external inductor-capacitor (LC) or resistor-inductor-capacitor (RLC) networks. The role of such network in the stabilization of the plasma discharge is investigated with a numerical model and the potential advantages of proportional-integral-derivative (PID) closed-loop control over RLC networks are subsequently assessed using either discharge voltage or magnetic field modulation. Simulations confirm the reduction of current oscillations in the presence of a RLC network, but suggest that PID control could ensure nearly oscillation-free operation with little sensitivity toward the PID settings.

  12. 78 FR 76294 - Underground Injection Control Program; Hazardous Waste Injection Restrictions; Petition for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-17

    ... Exemption--Class I Hazardous Waste Injection; Mosaic Fertilizer, LLC Uncle Sam, LA AGENCY: Environmental... Waste Amendments to the Resource Conservation and Recovery Act, has been granted to Mosaic...

  13. Screening of conditions controlling spectrophotometric sequential injection analysis

    PubMed Central

    2011-01-01

    Background Despite its potential benefits over univariate, chemometrics is rarely utilized for optimizing sequential injection analysis (SIA) methods. Specifically, in previous vis-spectrophotometric SIA methods, chemometrically optimized conditions were confined within flow rate and reagent concentrations while other conditions were ignored. Results The current manuscript reports, for the first time, a comprehensive screening of conditions controlling vis-spectrophotometric SIA. A new diclofenac assay method was adopted. The method was based on oxidizing diclofenac by permanganate (a major reagent) with sulfuric acid (a minor reagent). The reaction produced a spectrophotometrically detectable diclofenac form. The 26 full-factorial design was utilized to study the effect of volumes of reagents and sample, in addition to flow rate and concentrations of reagents. The main effects and all interaction order effects on method performance, i.e. namely sensitivity, rapidity and reagent consumption, were determined. The method was validated and applied to pharmaceutical formulations (tablets, injection and gel). Conclusions Despite 64 experiments those conducted in the current study were cumbersome, the results obtained would reduce effort and time when developing similar SIA methods in the future. It is recommended to critically optimize effective and interacting conditions using other such optimization tools as fractional-factorial design, response surface and simplex, rather than full-factorial design that used at an initial optimization stage. In vis-spectrophotometric SIA methods those involve developing reactions with two reagents (major and minor), conditions affecting method performance are in the following order: sample volume > flow rate ≈ major reagent concentration >> major reagent volume ≈ minor reagent concentration >> minor reagent volume. PMID:21333024

  14. Status and Future Developments in Large Accelerator Control Systems

    SciTech Connect

    Karen S. White

    2006-10-31

    Over the years, accelerator control systems have evolved from small hardwired systems to complex computer controlled systems with many types of graphical user interfaces and electronic data processing. Today's control systems often include multiple software layers, hundreds of distributed processors, and hundreds of thousands of lines of code. While it is clear that the next generation of accelerators will require much bigger control systems, they will also need better systems. Advances in technology will be needed to ensure the network bandwidth and CPU power can provide reasonable update rates and support the requisite timing systems. Beyond the scaling problem, next generation systems face additional challenges due to growing cyber security threats and the likelihood that some degree of remote development and operation will be required. With a large number of components, the need for high reliability increases and commercial solutions can play a key role towards this goal. Future control systems will operate more complex machines and need to present a well integrated, interoperable set of tools with a high degree of automation. Consistency of data presentation and exception handling will contribute to efficient operations. From the development perspective, engineers will need to provide integrated data management in the beginning of the project and build adaptive software components around a central data repository. This will make the system maintainable and ensure consistency throughout the inevitable changes during the machine lifetime. Additionally, such a large project will require professional project management and disciplined use of well-defined engineering processes. Distributed project teams will make the use of standards, formal requirements and design and configuration control vital. Success in building the control system of the future may hinge on how well we integrate commercial components and learn from best practices used in other industries.

  15. Magnetically Controlled Plasma Waveguide For Laser Wakefield Acceleration

    SciTech Connect

    Froula, D H; Divol, L; Davis, P; Palastro, J; Michel, P; Leurent, V; Glenzer, S H; Pollock, B; Tynan, G

    2008-05-14

    An external magnetic field applied to a laser plasma is shown produce a plasma channel at densities relevant to creating GeV monoenergetic electrons through laser wakefield acceleration. Furthermore, the magnetic field also provides a pressure to help shape the channel to match the guiding conditions of an incident laser beam. Measured density channels suitable for guiding relativistic short-pulse laser beams are presented with a minimum density of 5 x 10{sup 17} cm{sup -3} which corresponds to a linear dephasing length of several centimeters suitable for multi-GeV electron acceleration. The experimental setup at the Jupiter Laser Facility, Lawrence Livermore National Laboratory, where a 1-ns, 150 J 1054 nm laser will produce a magnetically controlled channel to guide a < 75 fs, 10 J short-pulse laser beam through 5-cm of 5 x 10{sup 17} cm{sup -3} plasma is presented. Calculations presented show that electrons can be accelerated to 3 GeV with this system. Three-dimensional resistive magneto-hydrodynamic simulations are used to design the laser and plasma parameters and quasi-static kinetic simulations indicate that the channel will guide a 200 TW laser beam over 5-cm.

  16. Enhanced acceleration of injected electrons in a laser-beat-wave-induced plasma channel.

    PubMed

    Tochitsky, S Ya; Narang, R; Filip, C V; Musumeci, P; Clayton, C E; Yoder, R B; Marsh, K A; Rosenzweig, J B; Pellegrini, C; Joshi, C

    2004-03-01

    Enhanced energy gain of externally injected electrons by a approximately 3 cm long, high-gradient relativistic plasma wave (RPW) is demonstrated. Using a CO2 laser beat wave of duration longer than the ion motion time across the laser spot size, a laser self-guiding process is initiated in a plasma channel. Guiding compensates for ionization-induced defocusing (IID) creating a longer plasma, which extends the interaction length between electrons and the RPW. In contrast to a maximum energy gain of 10 MeV when IID is dominant, the electrons gain up to 38 MeV energy in a laser-beat-wave-induced plasma channel. PMID:15089478

  17. Design of a Normal Acceleration and Angle of Attack Control System for a Missile Having Front and Rear Control Surfaces

    NASA Astrophysics Data System (ADS)

    Ochi, Yoshimasa

    Precise normal acceleration control is essential for missile guidance. Missiles with both front and rear control surfaces have a higher ability to control normal acceleration than missiles with front or rear control surfaces only. From the viewpoint of control, however, the control problem becomes a two-input-one-output problem, where generally control input cannot be determined uniquely. This paper proposes controlling angle of attack as well as normal acceleration, which makes the problem a two-input-two-output one and determines the controls uniquely. Normal acceleration command is given by a guidance system, but angle of attack command must be generated in accordance to the acceleration command without affecting the normal acceleration control. This paper also proposes such a command generator for angle of attack. Computer simulation is conducted using a nonlinear missile model to investigate the effectiveness of the control system along with control systems designed using three other methods.

  18. Computer control of large accelerators, design concepts and methods

    NASA Astrophysics Data System (ADS)

    Beck, F.; Gormley, M.

    1985-03-01

    Unlike most of the specialities treated in this volume, control system design is still an art, not a science. This presentation is an attempt to produce a primer for prospective practitioners of this art. A large modern accelerator requires a comprehensive control system for commissioning, machine studies, and day-to-day operation. Faced with the requirement to design a control system for such a machine, the control system architect has a bewildering array of technical devices and techniques at his disposal, and it is our aim in the following chapters to lead him through the characteristics of the problems he will have to face and the practical alternatives available for solving them. We emphasize good system architecture using commercially available hardware and software components, but in addition we discuss the actual control strategies which are to be implemented, since it is at the point of deciding what facilities shall be available that the complexity of the control system and its cost are implicitly decided.

  19. Computer control of large accelerators design concepts and methods

    SciTech Connect

    Beck, F.; Gormley, M.

    1984-05-01

    Unlike most of the specialities treated in this volume, control system design is still an art, not a science. These lectures are an attempt to produce a primer for prospective practitioners of this art. A large modern accelerator requires a comprehensive control system for commissioning, machine studies and day-to-day operation. Faced with the requirement to design a control system for such a machine, the control system architect has a bewildering array of technical devices and techniques at his disposal, and it is our aim in the following chapters to lead him through the characteristics of the problems he will have to face and the practical alternatives available for solving them. We emphasize good system architecture using commercially available hardware and software components, but in addition we discuss the actual control strategies which are to be implemented since it is at the point of deciding what facilities shall be available that the complexity of the control system and its cost are implicitly decided. 19 references.

  20. Lithium mass flow control for high power Lorentz Force Accelerators

    NASA Astrophysics Data System (ADS)

    Kodys, Andrea D.; Emsellem, Gregory; Cassady, Leonard D.; Polk, James E.; Choueiri, Edgar Y.

    2001-02-01

    A lithium feeding system has been developed to measure and control propellant flow for 30-200 kW Lithium Lorentz Force Accelerators (LiLFAs). The new, mechanically actuated, liquid lithium feed system has been designed and tested as a central component of a campaign to obtain basic data and establish scaling laws and performance relations for these thrusters. Calibration data are presented which demonstrate reliable and controllable feed of liquid lithium to the vaporizer hollow cathode of the thruster at flow rates between 10 and 120 mg/s. The ability to thermally track the liquid lithium through the system by the use of external temperature measurements is demonstrated. In addition, recent developments are presented in the establishment and successful testing of a lithium handling facility and safety procedures allowing for the in-house loading of the feed system and the neutralization, cleaning and disposal of up to 300 g of lithium. .

  1. Progestin-Only Hormonal Birth Control: Pill and Injection

    MedlinePlus

    ... disorders —Possible decrease in bleeding associated with uterine fibroids What are possible risks of the injection? Bone ... Estrogen: A female hormone produced in the ovaries. Fibroids: Benign growths that form in the muscle of ...

  2. A Framework for a General Purpose Intelligent Control System for Particle Accelerators. Phase II Final Report

    SciTech Connect

    Dr. Robert Westervelt; Dr. William Klein; Dr. Michael Kroupa; Eric Olsson; Rick Rothrock

    1999-06-28

    Vista Control Systems, Inc. has developed a portable system for intelligent accelerator control. The design is general in scope and is thus configurable to a wide range of accelerator facilities and control problems. The control system employs a multi-layer organization in which knowledge-based decision making is used to dynamically configure lower level optimization and control algorithms.

  3. High-Brightness Electron Accelerator Injection System and Experimental Studies of Laser-Induced Explosive Electron Emission.

    NASA Astrophysics Data System (ADS)

    Wang, Xijie

    1992-01-01

    Design studies for the Brookhaven Accelerator Test facility (ATF) injection system are presented. The injection system consists of a high-brightness electron source (photocathode RF gun) and a low-energy transport line. Cavity properties of the RF gun were measured, and found to agree with the calculated results obtained using the computer program SUPERFISH. We also studied the effect of using a non-symmetrical laser spot and RF focusing techniques to reduce the emittance growth in the injection system. A tracking program was developed to investigate higher-order effects on the transverse emittance and the bunch length of the electron beam in the transport line. Field-related electron emissions, i.e., field emission, the Schottky effect in photoemission and field -assisted thermionic emission, were measured. The effect of these electron emissions on the performance of the photocathode RF gun was studied. The possibility of using the momentum of the field emission current for measurement of the RF power in the RF gun was considered. Laser-induced explosive electron emission (EEE) was observed for the first time. It was found that the thresholds of the laser power for RF (80 MV/m) and DC (10 MV/m) cases are 10^9 W/cm ^2 and 10^{11} W/cm^2, respectively. No laser frequency dependence was detected. We infer a 1 muC charge with 20 A average current in RF case, and measured 0.17 muC for the DC situation from laser-induced EEE. The temporal structure of laser-induced EEE was measured. We discussed the possibility of using laser-induced EEE as electron and ion sources.

  4. Effect of additional optical pumping injection into the ground-state ensemble on the gain and the phase recovery acceleration of quantum-dot semiconductor optical amplifiers

    NASA Astrophysics Data System (ADS)

    Kim, Jungho

    2014-02-01

    The effect of additional optical pumping injection into the ground-state ensemble on the ultrafast gain and the phase recovery dynamics of electrically-driven quantum-dot semiconductor optical amplifiers is numerically investigated by solving 1088 coupled rate equations. The ultrafast gain and the phase recovery responses are calculated with respect to the additional optical pumping power. Increasing the additional optical pumping power can significantly accelerate the ultrafast phase recovery, which cannot be done by increasing the injection current density.

  5. Corrosion Effects of Calcium Chloride Injection for Mercury Control on the Pollution Control Equipment

    SciTech Connect

    Vijay Sethi; M.P. Sharma

    2009-02-28

    In response to the Clean Air Mercury Rule (CAMR) of 2005, Black Hills Power (BHP) initiated testing of a calcium chloride (CaCl{sub 2}) injection method in their Wygen 1 (Gillette, WY) coal-fired power plant to help lower mercury emissions. In 2006, Babcock & Wilcox (B&W) was contracted to test their CaCl{sub 2} technology in-situ by adding a CaCl{sub 2} solution onto the raw, pre-pulverized coal during normal operation of Wygen 1. Follow-up tests were conducted by BHP in 2007. Data were collected from these two time periods and analyzed by a collaborative investigation team from Western Research Institute (WRI) and the University of Wyoming (UW) to see if there were any effects on the current air pollution control systems. During a CaCl{sub 2} injection period in 2007, corrosion was monitored in the flue and recycle ash system by placing corrosion coupons in strategic locations to test if corrosion was enhanced by the CaCl{sub 2} injection. While the CaCl{sub 2} produced a reduction in stack mercury levels, there was some evidence of beneficial impacts on the removal of SO{sub 2} from the flue gas during CaCl{sub 2} injection. Data on NOx remained inconclusive. It was also discovered that corrosion was enhanced significantly in the Spray Drier Absorber (SDA) vessel and corresponding outlet ductwork during CaCl{sub 2} injections. Further studies are being carried out in the field and lab to better understand the corrosive effects of CaCl{sub 2} to help formulate operation controls to manage the increased corrosion rates.

  6. 77 FR 26231 - State of Tennessee; Underground Injection Control (UIC) Program Primacy

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-03

    ... AGENCY 40 CFR Part 147 State of Tennessee; Underground Injection Control (UIC) Program Primacy AGENCY: U... application from the State of Tennessee requesting approval of its Underground Injection Control program; 2... submitting comments. Email: marsh.nancy@epa.gov . Fax: (404) 562-9439. Mail: State of Tennessee;...

  7. Integrated Enterprise Accelerator Database for the SLC Control System

    NASA Astrophysics Data System (ADS)

    Lahey, T.; Rock, J.; Sass, R.; Shoaee, H.; Underwood, K.

    2002-08-01

    Since its inception in the early 1980's, the SLC Control System has been driven by a highly structured memory-resident real-time database. While efficient, its rigid structure and file-based sources makes it difficult to maintain and extract relevant information. The goal of transforming the sources for this database into a relational form is to enable it to be part of a Control System Enterprise Database that is an integrated central repository for SLC accelerator device and Control System data with links to other associated databases. We have taken the concepts developed for the NLC Enterprise Database and used them to create and load a relational model of the online SLC Control System database. This database contains data and structure to allow querying and reporting on beamline devices, their associations and parameters. queries tend to retrieve large numbers of rows and attribute tables can become large, adversely affecting performance. In addition, this model does not allow optimal use of database features such as constraints and joins, nor the standard set of database query and

  8. Experimental study of the reduction of field emission by gas injection in vacuum for accelerator applications

    NASA Astrophysics Data System (ADS)

    Almaksour, K.; Kirkpatrick, M. J.; Dessante, Ph.; Odic, E.; Simonin, A.; de Esch, H. P. L.; Lepetit, B.; Alamarguy, D.; Bayle, F.; Teste, Ph.

    2014-10-01

    Field emission current from surfaces under vacuum and at high field strengths can be reduced by the injection of gas into the evacuated volume. In this paper, the effects of H2, He, N2, and Ar on this "dark" current emitted from a tungsten carbide point cathode for 2 cm gap distance is studied. Exposure to any of these gases at pressures on the order of 10-3-10-2 Pa was found to reduce the emission current by up to 90% with a time constant on the order of ˜1 minute as compared to the current at 10-6 Pa. The effect was strongly dependent on the gas nature, with Ar and N2 having larger effects at lower pressures than He and H2. The reduction was reversible, with the current increasing to near its original value with a time constant on the order of ˜1-10 minutes after pumping down. The effect of the gas remained in the absence of electric field, whatever the gas pressure. Mechanisms for these and related phenomena are discussed.

  9. Microwave Ion Source and Beam Injection for an Accelerator-drivenNeutron Source

    SciTech Connect

    Vainionpaa, J.H.; Gough, R.; Hoff, M.; Kwan, J.W.; Ludewigt,B.A.; Regis, M.J.; Wallig, J.G.; Wells, R.

    2007-02-15

    An over-dense microwave driven ion source capable ofproducing deuterium (or hydrogen) beams at 100-200 mA/cm2 and with atomicfraction>90 percent was designed and tested with an electrostaticlow energy beam transport section (LEBT). This ion source wasincorporatedinto the design of an Accelerator Driven Neutron Source(ADNS). The other key components in the ADNS include a 6 MeV RFQaccelerator, a beam bending and scanning system, and a deuterium gastarget. In this design a 40 mA D+ beam is produced from a 6 mm diameteraperture using a 60 kV extraction voltage. The LEBT section consists of 5electrodes arranged to form 2 Einzel lenses that focus the beam into theRFQ entrance. To create the ECR condition, 2 induction coils are used tocreate ~; 875 Gauss on axis inside the source chamber. To prevent HVbreakdown in the LEBT a magnetic field clamp is necessary to minimize thefield in this region. Matching of the microwave power from the waveguideto the plasma is done by an autotuner. We observed significantimprovement of the beam quality after installing a boron nitride linerinside the ion source. The measured emittance data are compared withPBGUNS simulations.

  10. A comparison of acceleration control and pulse control in simulated spacecraft docking maneuvers

    NASA Technical Reports Server (NTRS)

    Brody, Adam R.; Ellis, Stephen R.

    1991-01-01

    Results are reported from a study designed to compare acceleration control with pulse control in simulated spacecraft docking maneuvers. Nine commercial airline pilots served as test subjects and the simulated remote dockings of an orbital maneuvering vehicle (OMV) to a space station were initiated from 50, 100, and 150 meters along the station's minus velocity vector. The trials were grouped into blocks of 18 consisting of six repetitions of the three ranges. It was found that mission duration was lower with pulse mode, while fuel consumption was lower with acceleration mode. It is suggested that this result is most likely specific to the thruster values that are being used.

  11. Spatially localized self-injection of electrons in a self-modulated laser-wakefield accelerator by using a laser-induced transient density ramp.

    PubMed

    Chien, T-Y; Chang, C-L; Lee, C-H; Lin, J-Y; Wang, J; Chen, S-Y

    2005-03-25

    By using a laser-induced transient density ramp, we demonstrate self-injection of electrons in a self-modulated laser-wakefield accelerator with spatial localization. The number of injected electrons reaches 1.7 x 10(8). The transient density ramp is produced by a prepulse propagating transversely to drill a density depression channel via ionization and expansion. The same mechanism of injection with comparable efficiency is also demonstrated with a transverse plasma waveguide driven by Coulomb explosion. PMID:15903867

  12. A Study of the Design of Acceleration Control System for Missiles

    NASA Astrophysics Data System (ADS)

    Kajita, Takanori; Eguchi, Hirofumi

    A 2-degrees of freedom PID controller is designed for a maneuvering acceleration control system. This design method is based on the combination of PID and IPD controller. Results show that (1) IP controller is superior to PI controller for the damper loop controller, (2) the selection of PI or IP controller as for the acceleration controller depends on the tradeoffs between the responsibility and the reduction of inverse response.

  13. Activated carbon injection - a mercury control success story

    SciTech Connect

    2008-07-01

    Almost 100 full-scale activated carbon injection (ACI) systems have been ordered by US electric utilities. These systems have the potential to remove over 90% of the mercury in flue, at a cost below $10,000 per pound of mercury removal. Field trials of ACI systems arm outlined. 1 fig.

  14. Best infection control practices for intradermal, subcutaneous, and intramuscular needle injections.

    PubMed Central

    Hutin, Yvan; Hauri, Anja; Chiarello, Linda; Catlin, Mary; Stilwell, Barbara; Ghebrehiwet, Tesfamicael; Garner, Julia

    2003-01-01

    OBJECTIVE: To draw up evidence-based guidelines to make injections safer. METHODS: A development group summarized evidence-based best practices for preventing injection-associated infections in resource-limited settings. The development process included a breakdown of the WHO reference definition of a safe injection into a list of potentially critical steps, a review of the literature for each of these steps, the formulation of best practices, and the submission of the draft document to peer review. FINDINGS: Eliminating unnecessary injections is the highest priority in preventing injection-associated infections. However, when intradermal, subcutaneous, or intramuscular injections are medically indicated, best infection control practices include the use of sterile injection equipment, the prevention of contamination of injection equipment and medication, the prevention of needle-stick injuries to the provider, and the prevention of access to used needles. CONCLUSION: The availability of best infection control practices for intradermal, subcutaneous, and intramuscular injections will provide a reference for global efforts to achieve the goal of safe and appropriate use of injections. WHO will revise the best practices five years after initial development, i.e. in 2005. PMID:12973641

  15. Flue gas injection control of silica in cooling towers.

    SciTech Connect

    Brady, Patrick Vane; Anderson, Howard L., Jr.; Altman, Susan Jeanne

    2011-06-01

    Injection of CO{sub 2}-laden flue gas can decrease the potential for silica and calcite scale formation in cooling tower blowdown by lowering solution pH to decrease equilibrium calcite solubility and kinetic rates of silica polymerization. Flue gas injection might best inhibit scale formation in power plant cooling towers that use impaired makeup waters - for example, groundwaters that contain relatively high levels of calcium, alkalinity, and silica. Groundwaters brought to the surface for cooling will degas CO{sub 2} and increase their pH by 1-2 units, possibly precipitating calcite in the process. Recarbonation with flue gas can lower the pHs of these fluids back to roughly their initial pH. Flue gas carbonation probably cannot lower pHs to much below pH 6 because the pHs of impaired waters, once outgassed at the surface, are likely to be relatively alkaline. Silica polymerization to form scale occurs most rapidly at pH {approx} 8.3 at 25 C; polymerization is slower at higher and lower pH. pH 7 fluids containing {approx}220 ppm SiO{sub 2} require > 180 hours equilibration to begin forming scale whereas at pH 8.3 scale formation is complete within 36 hours. Flue gas injection that lowers pHs to {approx} 7 should allow substantially higher concentration factors. Periodic cycling to lower recoveries - hence lower silica concentrations - might be required though. Higher concentration factors enabled by flue gas injection should decrease concentrate volumes and disposal costs by roughly half.

  16. Customizable electron beams from optically controlled laser plasma acceleration for γ-ray sources based on inverse Thomson scattering

    NASA Astrophysics Data System (ADS)

    Kalmykov, S. Y.; Davoine, X.; Ghebregziabher, I.; Shadwick, B. A.

    2016-09-01

    Laser wakefield acceleration of electrons in the blowout regime can be controlled by tailoring the laser pulse phase and the plasma target. The 100 nm-scale bandwidth and negative frequency chirp of the optical driver compensate for the nonlinear frequency red-shift imparted by wakefield excitation. This mitigates pulse self-steepening and suppresses continuous injection. The plasma channel suppresses diffraction of the pulse leading edge, further reducing self-steepening, making injection even quieter. Besides, the channel destabilizes the pulse tail confined within the accelerator cavity (the electron density "bubble"), causing oscillations in the bubble size. The resulting periodic injection generates background-free comb-like beams - sequences of synchronized, low phase-space volume bunches. Controlling the number of bunches, their energy, and energy spacing by varying the channel radius and the pulse length (as permitted by the large bandwidth) enables the design of a tunable, all-optical source of polychromatic, pulsed γ-rays using the mechanism of inverse Thomson scattering. Such source may radiate ~107 quasi-monochromatic 10 MeV-scale photons per shot into a microsteradian-scale observation angle. The photon energy is distributed among several distinct bands, each having sub-25% energy spread dictated by the mrad-scale divergence of electron beam.

  17. Control of soliton train transmission, storage, and clock recovery by cw light injection

    NASA Astrophysics Data System (ADS)

    Wabnitz, S.

    1996-12-01

    The Gordon-Haus time jitter and the soliton-soliton interactions in a soliton fiber loop memory or in a transmission link may be suppressed by the periodic injection of a weak cw control beam. In the case of a fiber ring cavity cw injection may also permit clock regeneration from a randomly modulated soliton train. .

  18. [Construction and implementation of quality control index for clinical safety of Chinese medicine injection].

    PubMed

    Jiang, Jun-jie; Xie, Yan-ming

    2015-12-01

    In order to ensure the authenticity and accuracy of traditional Chinese medicine injection safety monitoring data, Chinese medicine injection safety monitoring quality control indicators, including the monitoring center, monitoring personnel, hardware conditions, monitoring progress and the number of patients into the group, original documents and archives management, electronic data, adverse events, quality management were constructed. Its application in the creation of major new drugs technology major projects, 10 kinds of traditional Chinese medicine injections clinical safety monitoring quality control work, found the missing case surveillance, not reported adverse events, only reported adverse reactions, electronic data reporting lag, lack of level of efforts to control the problem, and corrected, the traditional Chinese medicine injection safety monitoring of quality control and quality assurance, and subsequent Chinese medicine safety monitoring quality control to provide the reference. PMID:27245020

  19. Borehole Investigation of the Effectiveness of Grout Injection Technology on Coal Mine Subsidence Control

    NASA Astrophysics Data System (ADS)

    Xuan, Dayang; Xu, Jialin; Wang, Binglong; Teng, Hao

    2015-11-01

    Grout injection into the horizontal fracture at the bed separation of an overburden is used as a surface subsidence control measure in coal-producing countries such as Poland, China, and Australia. However, the stiffness and distribution of the grouting mass in the post-injected overburden, as well as its effect on surface subsidence control, have not been investigated. To address these issues, two surface boreholes were drilled into the post-injected overburden above a longwall panel on the study site. It was found that the fly ash injected more than 7 months previously had become compacted. More than 90 % of the total fill was concentrated in the main injection section (MIS) of the overburden (thickness of 4.8-18.4 m). The MIS was located between the bottom of the injection borehole and the key stratum immediately above. Following injection, the central gob area received the maximum possible compression and served as the foundation of the support for the grout, allowing the grout to restrain the deformation of the strata above it, thus reducing surface subsidence. The results of this investigation may facilitate future injection design, thus improving the control of surface subsidence.

  20. An injectable, dual pH and oxidation-responsive supramolecular hydrogel for controlled dual drug delivery.

    PubMed

    Cheng, Xinfeng; Jin, Yong; Sun, Tongbing; Qi, Rui; Li, Hanping; Fan, Wuhou

    2016-05-01

    A novel pH and oxidation dual-responsive and injectable supramolecular hydrogel was developed, which was formed from multi-block copolymer poly(ether urethane) (PEU) and α-cyclodextrin (α-CD) inclusion complexes (ICs). The PEU copolymer was synthesized through a simple one-pot condensation polymerization of poly(ethylene glycol), di(1-hydroxyethylene) diselenide, dimethylolpropionic acid and 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate. In aqueous solution, the amphiphilic PEU copolymers could self-assemble into nanoparticles with dual pH and oxidation sensitivities, which can efficiently load and controllably release a hydrophobic drug indomethacin (IND). Then a dual-drug loaded supramolecular hydrogel was obtained by addition of α-CD and hydrophilic model drug (rhodamine B, RB) into the resulting IND-loaded PEU nanoparticle solution. The rheology studies showed that the supramolecular hydrogels with good injectability underwent a pH-induced reversible sol-gel transition and an oxidation-triggered degradation behavior. The in vitro drug release results demonstrated that the hydrogels showed dual drug release behavior and the release rates could be significantly accelerated by addition of an oxidizing agent (H2O2) or increasing the environmental pH. Therefore, this injectable and dual stimuli-responsive supramolecular hydrogel based codelivery systems could potentially be a promising candidate for controlled drug delivery systems. PMID:26851440

  1. Severe illness and death among injecting drug users in Scotland: a case-control study.

    PubMed

    Taylor, A; Hutchinson, S; Lingappa, J; Wadd, S; Ahmed, S; Gruer, L; Taylor, T H; Roy, K; Gilchrist, G; McGuigan, C; Penrice, G; Goldberg, D

    2005-04-01

    Between April and September 2000, 60 injecting drug users in Scotland died or were hospitalized with severe illness. Laboratory investigations suggested that Clostridium novyi and other bacteria were important aetiological agents. To determine associated environmental/behavioural factors a case-control study was undertaken with 19 'definite' and 32 'probable' cases in Glasgow, Scotland. For every deceased case (n=19), up to three proxy individuals were interviewed. Three controls were identified for each case. Multivariate logistic regression analyses compared (i) all cases and controls; (ii) definite cases and matched controls; (iii) probable cases and matched controls. In all three analyses injecting into muscle or skin and injecting most of the time with a filter used by someone else were the variables most strongly associated with illness. Comparing only muscle-injecting cases and controls, cases were significantly more likely to have injected larger amounts of heroin per average injection than were controls. The findings make an important epidemiological contribution to the understanding of the public health and clinical implications of the contamination of illicit drugs by histotoxic clostridia. PMID:15816144

  2. Simulation and experiment research on the proportional pressure control of water-assisted injection molding

    NASA Astrophysics Data System (ADS)

    Zhou, Hua; Chen, Yinglong; Zhang, Zengmeng; Yang, Huayong

    2012-05-01

    Water-assisted injection molding (WAIM), a newly developed fluid-assisted injection molding technology has drawn more and more attentions for the energy saving, short cooling circle time and high quality of products. Existing research for the process of WAIM has shown that the pressure control of the injecting water is mostly important for the WAIM. However, the proportional pressure control for the WAIM system is quite complex due to the existence of nonlinearities in the water hydraulic system. In order to achieve better pressure control performance of the injecting water to meet the requirements of the WAIM, the proportional pressure control of the WAIM system is investigated both numerically and experimentally. A newly designed water hydraulic system for WAIM is first modeled in AMEsim environment, the load characteristics and the nonlinearities of water hydraulic system are both considered, then the main factors affecting the injecting pressure and load flow rate are extensively studied. Meanwhile, an open-loop model-based compensation control strategy is employed to regulate the water injection pressure and a feedback proportional integrator controller is further adopted to achieve better control performance. In order to verify the AMEsim simulation results WAIM experiment for particular Acrylonitrile Butadiene Styrene (ABS) parts is implemented and the measured experimental data including injecting pressure and flow rate results are compared with the simulation. The good coincidence between experiment and simulation shows that the AMEsim model is accurate, and the tracking performance of the load pressure indicates that the proposed control strategy is effective for the proportional pressure control of the nonlinear WAIM system. The proposed proportional pressure control strategy and the conclusions drawn from simulation and experiment contribute to the application of water hydraulic proportional control and WAIM technology.

  3. Active Flow Separation Control of a Stator Vane Using Surface Injection in a Multistage Compressor Experiment

    NASA Technical Reports Server (NTRS)

    Culley, Dennis E.; Bright, Michelle M.; Prahst, Patricia S.; Strazisar, Anthony J.

    2003-01-01

    Micro-flow control actuation embedded in a stator vane was used to successfully control separation and improve near stall performance in a multistage compressor rig at NASA Glenn. Using specially designed stator vanes configured with internal actuation to deliver pulsating air through slots along the suction surface, a research study was performed to identify performance benefits using this microflow control approach. Pressure profiles and unsteady pressure measurements along the blade surface and at the shroud provided a dynamic look at the compressor during microflow air injection. These pressure measurements lead to a tracking algorithm to identify the onset of separation. The testing included steady air injection at various slot locations along the vane. The research also examined the benefit of pulsed injection and actively controlled air injection along the stator vane. Two types of actuation schemes were studied, including an embedded actuator for on-blade control. Successful application of an online detection and flow control scheme will be discussed. Testing showed dramatic performance benefit for flow reattachment and subsequent improvement in diffusion through the use of pulsed controlled injection. The paper will discuss the experimental setup, the blade configurations, and preliminary CFD results which guided the slot location along the blade. The paper will also show the pressure profiles and unsteady pressure measurements used to track flow control enhancement, and will conclude with the tracking algorithm for adjusting the control.

  4. A Shot Parameter Specification Subsystem for automated control of PBFA (Particle Beam Fusion Accelerator) II accelerator shots

    SciTech Connect

    Spiller, J.L.

    1987-01-01

    The Shot Parameter Specification Subsystem (SPSS) is an integral part of the automatic control system developed for the Particle Beam Fusion Accelerator II (PBFA II) by the Control Monitor (C/M) Software Development Team. This system has been designed to fully utilize the accelerator by tailoring shot parameters to the needs of the experimenters. The SPSS is the key to this flexibility. Automatic systems will be required on many pulsed power machines for the fastest turnaround, the highest reliability, and most cost effective operation. These systems will require the flexibility and the ease of use that is part of the SPSS. The PBFA II control system has proved to be an effective modular system, flexible enough to meet the demands of both the fast track construction of PBFA II and the control needs of Hermes III at the Simulation Technology Laboratory. This system is expected to meet the demands of most future machine changes.

  5. Measurement of performance using acceleration control and pulse control in simulated spacecraft docking operations

    NASA Technical Reports Server (NTRS)

    Brody, Adam R.; Ellis, Stephen R.

    1992-01-01

    Nine commercial airline pilots served as test subjects in a study to compare acceleration control with pulse control in simulated spacecraft maneuvers. Simulated remote dockings of an orbital maneuvering vehicle (OMV) to a space station were initiated from 50, 100, and 150 meters along the station's -V-bar (minus velocity vector). All unsuccessful missions were reflown. Five way mixed analysis of variance (ANOVA) with one between factor, first mode, and four within factors (mode, bloch, range, and trial) were performed on the data. Recorded performance measures included mission duration and fuel consumption along each of the three coordinate axes. Mission duration was lower with pulse mode, while delta V (fuel consumption) was lower with acceleration mode. Subjects used more fuel to travel faster with pulse mode than with acceleration mode. Mission duration, delta V, X delta V, Y delta V., and Z delta V all increased with range. Subjects commanded the OMV to 'fly' at faster rates from further distances. These higher average velocities were paid for with increased fuel consumption. Asymmetrical transfer was found in that the mode transitions could not be predicted solely from the mission duration main effect. More testing is advised to understand the manual control aspects of spaceflight maneuvers better.

  6. Sequential injection approach for simultaneous determination of ultratrace plutonium and neptunium in urine with accelerator mass spectrometry.

    PubMed

    Qiao, Jixin; Hou, Xiaolin; Roos, Per; Lachner, Johannes; Christl, Marcus; Xu, Yihong

    2013-09-17

    An analytical method was developed for simultaneous determination of ultratrace level plutonium (Pu) and neptunium (Np) using iron hydroxide coprecipitation in combination with automated sequential injection extraction chromatography separation and accelerator mass spectrometry (AMS) measurement. Several experimental parameters affecting the analytical performance were investigated and compared including sample preboiling operation, aging time, amount of coprecipitating reagent, reagent for pH adjustment, sedimentation time, and organic matter decomposition approach. The overall analytical results show that preboiling and aging are important for obtaining high chemical yields for both Pu and Np, which is possibly related to the aggregation and adsorption behavior of organic substances contained in urine. Although the optimal condition for Np and Pu simultaneous determination requires 5-day aging time, an immediate coprecipitation without preboiling and aging could also provide fairly satisfactory chemical yields for both Np and Pu (50-60%) with high sample throughput (4 h/sample). Within the developed method, (242)Pu was exploited as chemical yield tracer for both Pu and Np isotopes. (242)Pu was also used as a spike in the AMS measurement for quantification of (239)Pu and (237)Np concentrations. The results show that, under the optimal experimental condition, the chemical yields of (237)Np and (242)Pu are nearly identical, indicating the high feasibility of (242)Pu as a nonisotopic tracer for (237)Np determination in real urine samples. The analytical method was validated by analysis of a number of urine samples spiked with different levels of (237)Np and (239)Pu. The measured values of (237)Np and (239)Pu by AMS exhibit good agreement (R(2) ≥ 0.955) with the spiked ones confirming the reliability of the proposed method. PMID:23952680

  7. A Heading and Flight-Path Angle Control of Aircraft Based on Required Acceleration Vector

    NASA Astrophysics Data System (ADS)

    Yoshitani, Naoharu

    This paper describes a control of heading and flight-path angles of aircraft to time-varying command angles. The controller first calculates an acceleration command vector (acV), which is vertical to the velocity vector. acV consists of two components; the one is feedforward acceleration obtained from the rates of command angles, and the other is feedback acceleration obtained from angle deviations by using PID control law. A bank angle command around the velocity vector and commands of pitch and yaw rates are then obtained to generate the required acceleration. A roll rate command is calculated from bank angle deviation. Roll, pitch and yaw rate commands are put into the attitude controller, which can be composed of any suitable control laws such as PID control. The control requires neither aerodynamic coefficients nor online calculation of the inverse dynamics of the aircraft. A numerical simulation illustrates the effects of the control.

  8. Assessing sorbent injection mercury control effectiveness in flue gas streams

    USGS Publications Warehouse

    Carey, T.R.; Richardson, C.F.; Chang, R.; Meserole, F.B.; Rostam-Abadi, M.; Chen, S.

    2000-01-01

    One promising approach for removing mercury from coal-fired, utility flue gas involves the direct injection of mercury sorbents. Although this method has been effective at removing mercury in municipal waste incinerators, tests conducted to date on utility coal-fired boilers show that mercury removal is much more difficult in utility flue gas. EPRI is conducting research to investigate mercury removal using sorbents in this application. Bench-scale, pilot-scale, and field tests have been conducted to determine the ability of different sorbents to remove mercury in simulated and actual flue gas streams. This paper focuses on recent bench-scale and field test results evaluating the adsorption characteristics of activated carbon and fly ash and the use of these results to develop a predictive mercury removal model. Field tests with activated carbon show that adsorption characteristics measured in the lab agree reasonably well with characteristics measured in the field. However, more laboratory and field data will be needed to identify other gas phase components which may impact performance. This will allow laboratory tests to better simulate field conditions and provide improved estimates of sorbent performance for specific sites. In addition to activated carbon results, bench-scale and modeling results using fly ash are presented which suggest that certain fly ashes are capable of adsorbing mercury.

  9. PAB3D Simulations of a Nozzle with Fluidic Injection for Yaw Thrust-Vector Control

    NASA Technical Reports Server (NTRS)

    Deere, Karen A.

    1998-01-01

    An experimental and computational study was conducted on an exhaust nozzle with fluidic injection for yaw thrust-vector control. The nozzle concept was tested experimentally in the NASA Langley Jet Exit Test Facility (JETF) at nozzle pressure ratios up to 4 and secondary fluidic injection flow rates up to 15 percent of the primary flow rate. Although many injection-port geometries and two nozzle planforms (symmetric and asymmetric) were tested experimentally, this paper focuses on the computational results of the more successful asymmetric planform with a slot injection port. This nozzle concept was simulated with the Navier-Stokes flow solver, PAB3D, invoking the Shih, Zhu, and Lumley algebraic Reynolds stress turbulence model (ASM) at nozzle pressure ratios (NPRs) of 2,3, and 4 with secondary to primary injection flow rates (w(sub s)/w(sub p)) of 0, 2, 7 and 10 percent.

  10. Near-GeV-Energy Laser-Wakefield Acceleration of Self-Injected Electrons in a Centimeter-Scale Plasma Channel

    NASA Astrophysics Data System (ADS)

    Tsung, F. S.; Narang, Ritesh; Mori, W. B.; Joshi, C.; Fonseca, R. A.; Silva, L. O.

    2004-10-01

    The first three-dimensional, particle-in-cell (PIC) simulations of laser-wakefield acceleration of self-injected electrons in a 0.84cm long plasma channel are reported. The frequency evolution of the initially 50fs (FWHM) long laser pulse by photon interaction with the wake followed by plasma dispersion enhances the wake which eventually leads to self-injection of electrons from the channel wall. This first bunch of electrons remains spatially highly localized. Its phase space rotation due to slippage with respect to the wake leads to a monoenergetic bunch of electrons with a central energy of 0.26GeV after 0.55cm propagation. At later times, spatial bunching of the laser enhances the acceleration of a second bunch of electrons to energies up to 0.84GeV before the laser pulse intensity is significantly reduced.

  11. Near-GeV-energy laser-wakefield acceleration of self-injected electrons in a centimeter-scale plasma channel.

    PubMed

    Tsung, F S; Narang, Ritesh; Mori, W B; Joshi, C; Fonseca, R A; Silva, L O

    2004-10-29

    The first three-dimensional, particle-in-cell (PIC) simulations of laser-wakefield acceleration of self-injected electrons in a 0.84 cm long plasma channel are reported. The frequency evolution of the initially 50 fs (FWHM) long laser pulse by photon interaction with the wake followed by plasma dispersion enhances the wake which eventually leads to self-injection of electrons from the channel wall. This first bunch of electrons remains spatially highly localized. Its phase space rotation due to slippage with respect to the wake leads to a monoenergetic bunch of electrons with a central energy of 0.26 GeV after 0.55 cm propagation. At later times, spatial bunching of the laser enhances the acceleration of a second bunch of electrons to energies up to 0.84 GeV before the laser pulse intensity is significantly reduced. PMID:15525172

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

    DOEpatents

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

    2014-05-13

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

  13. Method of controlling injection of oxygen into hydrogen-rich fuel cell feed stream

    DOEpatents

    Meltser, Mark Alexander; Gutowski, Stanley; Weisbrod, Kirk

    2001-01-01

    A method of operating a H.sub.2 --O.sub.2 fuel cell fueled by hydrogen-rich fuel stream containing CO. The CO content is reduced to acceptable levels by injecting oxygen into the fuel gas stream. The amount of oxygen injected is controlled in relation to the CO content of the fuel gas, by a control strategy that involves (a) determining the CO content of the fuel stream at a first injection rate, (b) increasing the O.sub.2 injection rate, (c) determining the CO content of the stream at the higher injection rate, (d) further increasing the O.sub.2 injection rate if the second measured CO content is lower than the first measured CO content or reducing the O.sub.2 injection rate if the second measured CO content is greater than the first measured CO content, and (e) repeating steps a-d as needed to optimize CO consumption and minimize H.sub.2 consumption.

  14. Impact of the underground injection control program on energy resource development

    SciTech Connect

    Allen, E.P.

    1983-10-01

    Part C of the Safe Drinking Water Act requires that underground sources of drinking water be protected from endangerment by well injection. The Act, as amended through 1980, and the resultant Underground Injection Control (UIC) program regulations and guidance describe minimum requirements for achieving this protection. Injection wells used in the development of energy resources, for example, those related to oil and natural gas production, and the solution mining of uranium, are regulated under the UIC program. The major features of the program requirements that affect such energy related wells are considered here from the Federal-Regional perspective.

  15. Control of light polarization using optically spin-injected vertical external cavity surface emitting lasers

    SciTech Connect

    Frougier, J. Jaffrès, H.; Deranlot, C.; George, J.-M.; Baili, G.; Dolfi, D.; Alouini, M.; Sagnes, I.; Garnache, A.

    2013-12-16

    We fabricated and characterized an optically pumped (100)-oriented InGaAs/GaAsP multiple quantum well Vertical External Cavity Surface Emitting Laser (VECSEL). The structure is designed to allow the integration of a Metal-Tunnel-Junction ferromagnetic spin-injector for future electrical injection. We report here the control at room temperature of the electromagnetic field polarization using optical spin injection in the active medium of the VECSEL. The switching between two highly circular polarization states had been demonstrated using an M-shaped extended cavity in multi-modes lasing. This result witnesses an efficient spin-injection in the active medium of the LASER.

  16. Medroxyprogesterone Injection

    MedlinePlus

    ... Medroxyprogesterone injection is a very effective method of birth control but does not prevent the spread of human ... you have been using a different method of birth control and are switching to medroxyprogesterone injection, your doctor ...

  17. Percutaneous Cyanoacrylate Glue Injection into the Renal Pseudoaneurysm to Control Intractable Hematuria After Percutaneous Nephrolithotomy

    SciTech Connect

    Lal, Anupam Kumar, Ajay; Prakash, Mahesh; Singhal, Manphool; Agarwal, Mayank Mohan; Sarkar, Debansu; Khandelwal, Niranjan

    2009-07-15

    We report a case of a 43-year-old man who developed intractable hematuria after percutaneous nephrolithotomy. Angiography detected a pseudoaneurysm arising from the lower polar artery; however, embolization could not be performed because of unfavorable vascular anatomy. A percutaneous thrombin injection under ultrasound guidance initially controlled the bleeding, but hematuria subsequently recurred as a result of recanalization of the aneurysm. The case was successfully managed with ultrasound- and fluoroscopic-guided direct injection of cyanoacrylate glue into the pseudoaneurysm.

  18. Generation of 500 MeV-1 GeV energy electrons from laser wakefield acceleration via ionization induced injection using CO{sub 2} mixed in He

    SciTech Connect

    Mo, M. Z.; Ali, A.; Fedosejevs, R.; Fourmaux, S.; Lassonde, P.; Kieffer, J. C.

    2013-04-01

    Laser wakefield acceleration of 500 MeV to 1 GeV electron bunches has been demonstrated using ionization injection in mixtures of 4% to 10% of CO{sub 2} in He. 80 TW laser pulses were propagated through 5 mm gas jet targets at electron densities of 0.4-1.5 Multiplication-Sign 10{sup 19}cm{sup -3}. Ionization injection led to lower density thresholds, a higher total electron charge, and an increased probability of producing electrons above 500 MeV in energy compared to self-injection in He gas alone. Electrons with GeV energies were also observed on a few shots and indicative of an additional energy enhancement mechanism.

  19. Energy shaping non-linear acceleration control for a pendulum-type mobility and experimental verification

    NASA Astrophysics Data System (ADS)

    Yokoyama, Kazuto; Takahashi, Masaki

    2015-02-01

    A dynamics-based non-linear controller with energy shaping to accelerate a pendulum-type mobility is proposed. The concept of this study is to control translational acceleration of the vehicle in a dynamically reasonable manner. The body angle is controlled to maintain a reference state where the vehicle is statically unstable but dynamically stable, which leads to a constant translational acceleration due to instability of the system. The accelerating motion is like a sprinter moving from crouch start and it fully exploits dynamics of the vehicle. To achieve it, the total energy of the system is shaped to have the minimum at a given reference state and the system is controlled to converge to it. The controller can achieve various properties through the energy shaping procedure. Especially, an energy function that will lead to safe operation of the vehicle is proposed. The effectiveness of the controller is verified in simulations and experiments.

  20. Pressure-controlled injection of guar gum stabilized microscale zerovalent iron for groundwater remediation.

    PubMed

    Luna, M; Gastone, F; Tosco, T; Sethi, R; Velimirovic, M; Gemoets, J; Muyshondt, R; Sapion, H; Klaas, N; Bastiaens, L

    2015-10-01

    The paper reports a pilot injection test of microsized zerovalent iron (mZVI) dispersed in a guar gum shear thinning solution. The test was performed in the framework of the EU research project AQUAREHAB in a site in Belgium contaminated by chlorinated aliphatic hydrocarbons (CAHs). The field application was aimed to overcome those critical aspects which hinder mZVI field injection, mainly due to the colloidal instability of ZVI-based suspensions. The iron slurry properties (iron particles size and concentration, polymeric stabilizer type and concentration, slurry viscosity) were designed in the laboratory based on several tests (reactivity tests towards contaminants, sedimentation tests and rheological measurements). The particles were delivered into the aquifer through an injection well specifically designed for controlled-pressure delivery (approximately 10 bars). The well characteristics and the critical pressure of the aquifer (i.e. the injection pressure above which fracturing occurs) were assessed via two innovative injection step rate tests, one performed with water and the other one with guar gum. Based on laboratory and field preliminary tests, a flow regime at the threshold between permeation and preferential flow was selected for mZVI delivery, as a compromise between the desired homogeneous distribution of the mZVI around the injection point (ensured by permeation flow) and the fast and effective injection of the slurry (guaranteed by high discharge rates and injection pressure, resulting in the generation of preferential flow paths). A monitoring setup was designed and installed for the real-time monitoring of relevant parameters during injection, and for a fast determination of the spatial mZVI distribution after injection via non-invasive magnetic susceptibility measurements. PMID:25971233

  1. Design of Control Server Application Software for Neutral Beam Injection System

    NASA Astrophysics Data System (ADS)

    Shi, Qilin; Hu, Chundong; Sheng, Peng; Song, Shihua

    2012-04-01

    For the remote control of a neutral beam injection (NBI) system, a software NBIcsw is developed to work on the control server. It can meet the requirements of data transmission and operation-control between the NBI measurement and control layer (MCL) and the remote monitoring layer (RML). The NBIcsw runs on a Linux system, developed with client/server (C/S) mode and multithreading technology. It is shown through application that the software is with good efficiency.

  2. Optimization of Trona/Limestone Injection for SO2 Control in Coal-Fired Boilers

    SciTech Connect

    2005-09-01

    Mobotec USA develops and markets air pollution control systems for utility boilers and other combustion systems. They have a particular interest in technologies that can reduce NOx, SOx, and mercury emissions from coal-fired boilers, and have been investigating the injection of sorbents such as limestone and trona into a boiler to reduce SOx and Hg emissions. WRI proposed to use the Combustion Test Facility (CTF) to enable Mobotec to conduct a thorough evaluation of limestone and trona injection for SO{sub 2} control. The overall goal of the project was to characterize the SO{sub 2} reductions resulting from the injection of limestone and trona into the CTF when fired with a high-sulfur eastern bituminous coal used in one of Mobotec's Midwest installations. Results revealed that when limestone was injected at Ca:S molar ratios of 1.5 to 3.0, the resulting SO{sub 2} reductions were 35-55%. It is believed that further reductions can be attained with improved mixing of the sorbent with the combustion gases. When limestone was added to the coal, at Ca:S molar ratios of 0.5 to 1.5, the SO{sub 2} reductions were 13-21%. The lower reductions were attributed to dead-burning of the sorbent in the high temperature flame zone. In cases where limestone was both injected into the furnace and added to the coal, the total SO{sub 2} reductions for a given Ca:S molar ratio were similar to the reductions for furnace injection only. The injection of trona into the mid-furnace zone, for Na:S molar ratios of 1.4 to 2.4, resulted in SO{sub 2} reductions of 29-43%. Limestone injection did not produce any slag deposits on an ash deposition probe while trona injection resulted in noticeable slag deposition.

  3. Control of focusing fields for positron acceleration in nonlinear plasma wakes using multiple laser modes

    SciTech Connect

    Yu, L.-L. Li, F.-Y.; Chen, M.; Weng, S.-M.; Schroeder, C. B.; Benedetti, C.; Esarey, E.; Sheng, Z.-M.

    2014-12-15

    Control of transverse wakefields in the nonlinear laser-driven bubble regime using a combination of Hermite-Gaussian laser modes is proposed. By controlling the relative intensity ratio of the two laser modes, the focusing force can be controlled, enabling matched beam propagation for emittance preservation. A ring bubble can be generated with a large longitudinal accelerating field and a transverse focusing field suitable for positron beam focusing and acceleration.

  4. Two-photon indirect optical injection and two-color coherent control in bulk silicon

    NASA Astrophysics Data System (ADS)

    Cheng, J. L.; Rioux, J.; Sipe, J. E.

    2011-12-01

    Using an empirical pseudopotential description of electron states and an adiabatic bond charge model for phonon states in bulk silicon, we theoretically investigate two-photon indirect optical injection of carriers and spins and two-color coherent control of the motion of the injected carriers and spins. For two-photon indirect carrier and spin injection, we identify the selection rules of band edge transitions, the injection in each conduction band valley, and the injection from each phonon branch at 4 and 300 K. At 4 K, the TA-phonon-assisted transitions dominate the injection at low photon energies and the TO-phonon-assisted transitions at high photon energies. At 300 K, the former dominates at all photon energies of interest. The carrier injection shows anisotropy and linear-circular dichroism with respect to the light propagation direction. For light propagating along the <001> direction, the carrier injection exhibits valley anisotropy, and the injection into the Z conduction band valley is larger than that into the X and Y valleys. For σ- light propagating along the <001> (<111>) direction, the degree of spin polarization gives a maximum value about 20% (6%) at 4 K and -10% (20%) at 300 K, and at both temperature shows abundant structure near the injection edges due to contributions from different phonon branches. For two-color coherent current injection with an incident optical field composed of a fundamental frequency and its second harmonic, the response tensors of the electron (hole) charge and spin currents are calculated at 4 and 300 K. We show the current control for three different polarization scenarios: For cocircularly polarized beams, the direction of the charge current and the polarization direction of the spin current can be controlled by a relative-phase parameter; for the collinearly and cross-linearly polarized beams, the current amplitude can be controlled by that parameter. The spectral dependence of the maximum swarm velocity shows that

  5. Image processing and computer controls for video profile diagnostic system in the ground test accelerator (GTA)

    SciTech Connect

    Wright, R.M.; Zander, M.E.; Brown, S.K.; Sandoval, D.P.; Gilpatrick, J.D.; Gibson, H.E.

    1992-09-01

    This paper describes the application of video image processing to beam profile measurements on the Ground Test Accelerator (GTA). A diagnostic was needed to measure beam profiles in the intermediate matching section (IMS) between the radio-frequency quadrupole (RFQ) and the drift tube linac (DTL). Beam profiles are measured by injecting puffs of gas into the beam. The light emitted from the beam-gas interaction is captured and processed by a video image processing system, generating the beam profile data. A general purpose, modular and flexible video image processing system, imagetool, was used for the GTA image profile measurement. The development of both software and hardware for imagetool and its integration with the GTA control system (GTACS) will be discussed. The software includes specialized algorithms for analyzing data and calibrating the system. The underlying design philosophy of imagetool was tested by the experience of building and using the system, pointing the way for future improvements. The current status of the system will be illustrated by samples of experimental data.

  6. Image processing and computer controls for video profile diagnostic system in the ground test accelerator (GTA)

    SciTech Connect

    Wright, R.M.; Zander, M.E.; Brown, S.K.; Sandoval, D.P.; Gilpatrick, J.D.; Gibson, H.E.

    1992-01-01

    This paper describes the application of video image processing to beam profile measurements on the Ground Test Accelerator (GTA). A diagnostic was needed to measure beam profiles in the intermediate matching section (IMS) between the radio-frequency quadrupole (RFQ) and the drift tube linac (DTL). Beam profiles are measured by injecting puffs of gas into the beam. The light emitted from the beam-gas interaction is captured and processed by a video image processing system, generating the beam profile data. A general purpose, modular and flexible video image processing system, imagetool, was used for the GTA image profile measurement. The development of both software and hardware for imagetool and its integration with the GTA control system (GTACS) will be discussed. The software includes specialized algorithms for analyzing data and calibrating the system. The underlying design philosophy of imagetool was tested by the experience of building and using the system, pointing the way for future improvements. The current status of the system will be illustrated by samples of experimental data.

  7. Longitudinal Bunch Position Control for the Super-B Accelerator

    SciTech Connect

    Bertsche, Kirk; Rivetta, Claudio; Sullivam, Michael K.; Drago, Alessandro; /Frascati

    2009-05-15

    The use of normal conducting cavities and an ion-clearing gap will cause a significant RF accelerating voltage gap transient and longitudinal phase shift of the individual bunches along the bunch train in both rings of the SuperB accelerator. Small relative centroid position shifts between bunches of the colliding beams will have a large adverse impact on the luminosity due to the small {beta}*{sub y} at the interaction point (IP). We investigate the possibility of minimizing the relative longitudinal position shift between bunches by reducing the gap transient in each ring and matching the longitudinal bunch positions of the two rings at the IP using feedback/feedforward techniques in the LLRF. The analysis is conducted assuming maximum use of the klystron power installed in the system.

  8. Investigations of stability and dynamic performances of switching regulators employing current-injected control

    NASA Technical Reports Server (NTRS)

    Lee, F. C.; Carter, R. A.

    1981-01-01

    The stability and dynamic performances of a buck/boost regulator employing a current-injected control are examined. Small-signal models for the power state, the multi-loop error processor and the duty-cycle pulse-modulator are developed. The error-processor model which incorporates the current-injected loop, the dc loop and the compensation network permits evaluation of the effects of each individual control loop and their combined efforts toward shaping the performance characteristics of the closed-loop system. Comparisons are made between this modeling approach and earlier approaches. Some important yet subtle dissimilarities are discussed. This model predicts the constant-frequency 50 percent duty-cycle instability which is inherent to the current-injected control.

  9. A gel aspiration-ejection system for the controlled production and delivery of injectable dense collagen scaffolds.

    PubMed

    Kamranpour, Neysan O; Miri, Amir K; James-Bhasin, Mark; Nazhat, Showan N

    2016-03-01

    A gel aspiration-ejection (GAE) system has been developed for the advanced production and delivery of injectable dense collagen (I-DC) gels of unique collagen fibrillar densities (CFDs). Through the creation of negative pressure, GAE aspirates prefabricated highly hydrated collagen gels into a needle, simultaneously inducing compaction and meso-scale anisotropy (i.e., fibrillar alignment) on the gels, and by subsequent reversal of the pressure, I-DC gels can be controllably ejected. The system generates I-DC gels with CFDs ranging from 5 to 32 wt%, controlling the initial scaffold microstructure, anisotropy, hydraulic permeability, and mechanical properties. These features could potentially enable the minimally invasive delivery of more stable hydrogels. The viability, metabolic activity, and differentiation of seeded mesenchymal stem cells (MSCs) was investigated in the I-DC gels of distinct CFDs and extents of anisotropy produced through two different gauge needles. MSC osteoblastic differentiation was found to be relatively accelerated in I-DC gels that combined physiologically relevant CFDs and increased fibrillar alignment. The ability to not only support homogenous cell seeding, but also to direct and accelerate their differentiation through tissue-equivalent anisotropy, creates numerous opportunities in regenerative medicine. PMID:27003606

  10. Controle de la fabrication des composites par injection sur renforts

    NASA Astrophysics Data System (ADS)

    Lebel, Francois

    Liquid Composite Molding (LCM) is an increasingly used class of processes to manufacture high performance composites. A multiscale study is presented in this thesis in order to better understand the fundamental physics of impregnation and air entrapment phenomena in dual scale fibrous reinforcements and thus propose practical solutions for process control engineers. First of all, an experimental setup is developed to study the saturation of fibrous reinforcements, at the macroscopic scale, during the Resin Transfer Molding (RTM). This setup is used to determine some key parameters of the part filling step and industrial post-filling strategies (mold bleeding and consolidation) that control the impregnation quality of fibrous reinforcements. These key parameters are identified using three series of experiments. These parameters are the flow front velocity, the inlet mold pressure and the bleeding flow rate. The analyses in these three series of experiments are based on an ASTM standard procedure for void content determination in the composite parts by carbonization (also called loss on ignition (LOI)). These three series of experiments have related a posteriori the key parameters of LCM processes to phenomena of void formation, migration and dissolution in composite parts made of E-glass non crimp fabric (NCF) and vinyl ester resin. The second part of this thesis aims to investigate, at the mesoscopic and microscopic scale, the impregnation mechanisms of fibrous reinforcements during LCM processes. This analysis focuses more specifically on wicking phenomenon in fiber tows and in fibrous laminates, namely here stacks of non crimp fabric plies. This experimental study is carried out to better understand the physics which explain that the impregnation velocity is one of the key parameters that control the quality of composite parts manufactured by LCM processes. This analysis also aims to identify the structural features of fiber tows and fibrous reinforcements that

  11. The impact of including corticosteroid in a periarticular injection for pain control after total knee arthroplasty

    PubMed Central

    Tsukada, S.; Wakui, M.; Hoshino, A.

    2016-01-01

    There is conflicting evidence about the benefit of using corticosteroid in periarticular injections for pain relief after total knee arthroplasty (TKA). We carried out a double-blinded, randomised controlled trial to assess the efficacy of using corticosteroid in a periarticular injection to control pain after TKA. A total of 77 patients, 67 women and ten men, with a mean age of 74 years (47 to 88) who were about to undergo unilateral TKA were randomly assigned to have a periarticular injection with or without corticosteroid. The primary outcome was post-operative pain at rest during the first 24 hours after surgery, measured every two hours using a visual analogue pain scale score. The cumulative pain score was quantified using the area under the curve. The corticosteroid group had a significantly lower cumulative pain score than the no-corticosteroid group during the first 24 hours after surgery (mean area under the curve 139, 0 to 560, and 264, 0 to 1460; p = 0.024). The rate of complications, including surgical site infection, was not significantly different between the two groups up to one year post-operatively. The addition of corticosteroid to the periarticular injection significantly decreased early post-operative pain. Further studies are needed to confirm the safety of corticosteroid in periarticular injection. Take home message: The use of corticosteroid in periarticular injection offered better pain relief during the initial 24 hours after TKA. Cite this article: Bone Joint J 2016;98-B:194–200. PMID:26850424

  12. Real-time Optical Network for Accelerator Control

    SciTech Connect

    Lee, Keun

    2012-06-27

    The timing requirements of a modern accelerator complex call for several features. The first is a system for high precision relative timing among accelerator components. Stabilized fiber links have already been demonstrated to achieve sub-10 femtoseconds relative timing precision. The second is a system for timing distribution of absolute time with sufficient precision to identify a specific RF bucket. The White Rabbit technology is a promising candidate to deliver the absolute time that is linked to the GPS clock. In this study we demonstrated that these two technologies can be combined in a way that the absolute time information can be delivered to the stabilized fiber link system. This was accomplished by researching the design of the stabilized fiber and White Rabbit systems and devising adaptation modules that facilitate co-existence of both systems in the same FPGA environment. We built a prototype system using off-the-shelf products and implemented a proof-of-concept version of the FPGA firmware. The test verified that the White Rabbit features operate correctly under the stabilized fiber system environment. This work demonstrates that turn-key femtosecond timing systems with absolute time information can be built cost effectively and deployed in various accelerator environments. This will lead to many new applications in chemistry, biology and surface dynamics, to name a few.

  13. Injection slot location for boundary-layer control in shock-induced separation

    NASA Technical Reports Server (NTRS)

    Viswanath, P. R.; Sankaran, L.; Sagdeo, P. M.; Narasimha, R.; Prabhu, A.

    1978-01-01

    An experimental investigation of the effect of tangential air injection, when the injection slot is located inside of what would otherwise have been the dead air zone in a separated flow, in controlling shock-induced turbulent boundary layer separation is presented. The experiments were carried out at a free-stream Mach number of 2.5 in the separated flow induced by a compression corner with a 20 deg angle. The observations made were wall static pressures, pitot profiles, and schlieren visualizations of the flow. The results show that the present location for injection is more effective in suppressing boundary-layer separation than the more conventional one, where the slot is located upstream of where separation would occur in the absence of injection.

  14. High-Flux Femtosecond X-Ray Emission from Controlled Generation of Annular Electron Beams in a Laser Wakefield Accelerator.

    PubMed

    Zhao, T Z; Behm, K; Dong, C F; Davoine, X; Kalmykov, S Y; Petrov, V; Chvykov, V; Cummings, P; Hou, B; Maksimchuk, A; Nees, J A; Yanovsky, V; Thomas, A G R; Krushelnick, K

    2016-08-26

    Annular quasimonoenergetic electron beams with a mean energy in the range 200-400 MeV and charge on the order of several picocoulombs were generated in a laser wakefield accelerator and subsequently accelerated using a plasma afterburner in a two-stage gas cell. Generation of these beams is associated with injection occurring on the density down ramp between the stages. This well-localized injection produces a bunch of electrons performing coherent betatron oscillations in the wakefield, resulting in a significant increase in the x-ray yield. Annular electron distributions are detected in 40% of shots under optimal conditions. Simultaneous control of the pulse duration and frequency chirp enables optimization of both the energy and the energy spread of the annular beam and boosts the radiant energy per unit charge by almost an order of magnitude. These well-defined annular distributions of electrons are a promising source of high-brightness laser plasma-based x rays. PMID:27610860

  15. Ultra-low emittance beam generation using two-color ionization injection in a CO2 laser-driven plasma accelerator

    SciTech Connect

    Schroeder, Carl; Benedetti, Carlo; Bulanov, Stepan; Chen, Min; Esarey, Eric; Geddes, Cameron; Vay, J.; Yu, Lule; Leemans, Wim

    2015-05-21

    Ultra-low emittance (tens of nm) beams can be generated in a plasma accelerator using ionization injection of electrons into a wakefield. An all-optical method of beam generation uses two laser pulses of different colors. A long-wavelength drive laser pulse (with a large ponderomotive force and small peak electric field) is used to excite a large wakefield without fully ionizing a gas, and a short-wavelength injection laser pulse (with a small ponderomotive force and large peak electric field), co-propagating and delayed with respect to the pump laser, to ionize a fraction of the remaining bound electrons at a trapped wake phase, generating an electron beam that is accelerated in the wake. The trapping condition, the ionized electron distribution, and the trapped bunch dynamics are discussed. Expressions for the beam transverse emittance, parallel and orthogonal to the ionization laser polarization, are presented. An example is shown using a 10-micron CO2 laser to drive the wake and a frequency-doubled Ti:Al2O3 laser for ionization injection.

  16. Electron acceleration in a two-stage laser wakefield accelerator

    NASA Astrophysics Data System (ADS)

    Li, Ruxin; Liu, Jiansheng; Xia, Changquan; Wang, Wentao; Lu, Haiyang; Wang, Cheng; Deng, Aihua; Li, Wentao; Zhang, Hui; Liang, Xiaoyan; Leng, Yuxin; Lu, Xiaoming; Wang, Cheng; Wang, Jianzhou; Shen, Baifei; Nakajima, Kazuhisa; Xu, Zhizhan

    2012-07-01

    Near-GeV electron beam generation from a two-stage laser wakefield accelerator (LWFA) is reported. Electron injection and acceleration are separated into two distinct LWFA stages and controlled independently from each other by employing two gas cells filled with a He/O2 mixture and pure He gas, respectively. Electrons with a Maxwellian spectrum, generated from the injection stage assisted by ionization-induced injection, are seeded into the acceleration stage with a 3-mm long gas cell and accelerated to produce a 0.8-GeV quasimonoenergetic electron beam for a 45 TW 40 fs laser pulse, corresponding to an acceleration gradient of 187 GV/m. In the injection stage, the produced electron beam properties can be optimized by adjusting the input laser intensity and the plasma density so that quasimonoenergetic electron beams are obtained owing to the self-focusing effects of the laser beam. The ionization-induced injection scheme has been extensively employed for a capillary discharge plasma waveguide to demonstrate channel-guided LWFA beyond 1 GeV. Using a 4-cm capillary made of oxygen containing acrylic resin results in optically guiding 130 TW 55 fs laser pulse that accelerates electrons up to 1.8 GeV in contrast with no electron acceleration in a polyethylene capillary free of oxygen.

  17. Fast electron spin resonance controlled manipulation of spin injection into quantum dots

    SciTech Connect

    Merz, Andreas Siller, Jan; Schittny, Robert; Krämmer, Christoph; Kalt, Heinz; Hetterich, Michael

    2014-06-23

    In our spin-injection light-emitting diodes, electrons are spin-polarized in a semimagnetic ZnMnSe spin aligner and then injected into InGaAs quantum dots. The resulting electron spin state can be read out by measuring the circular polarization state of the emitted light. Here, we resonantly excite the Mn 3d electron spin system with microwave pulses and perform time-resolved measurements of the spin dynamics. We find that we are able to control the spin polarization of the injected electrons on a microsecond timescale. This electron spin resonance induced spin control could be one of the ingredients required to utilize the quantum dot electrons or the Mn spins as qubits.

  18. The Diagnosis of the Os Trigonum Syndrome with a Fluoroscopically Controlled Injection of Local Anesthetic

    PubMed Central

    Jones, Darron M; Saltzman, Charles L; El-Khoury, George

    1999-01-01

    Purpose To report the results of excision of the os trigonum using a fluoroscopically controlled injection of local anesthetic to diagnose the os trigonum syndrome. Design and patients Os trigonum syndrome is a recognized cause of pain in the posterior aspect of the foot and ankle. The symptoms and physical findings, however, are often nonspecific and difficult to differentiate from other causes of posterior ankle pain. We report four patients with persistent posterolateral ankle pain despite prolonged nonoperative treatment. An os trigonal syndrome was diagnosed by a positive response to a fluoroscopically guided local anesthetic injection in the region of synchondrosis between the os trigonum and the posterior talus. Results All four patients underwent excision of the os trigonum with complete resolution of symptoms and return to full activity. Conclusions Fluoroscopically controlled injection can help confirm the suspected diagnosis of an os trigonum syndrome and may have positive predictive value regarding the outcome of excisional surgery. PMID:10847526

  19. Paraspinous Lidocaine Injection for Chronic Nonspecific Low Back Pain: A Randomized Controlled Clinical Trial

    PubMed Central

    Imamura, Marta; Imamura, Satiko Tomikawa; Targino, Rosa Alves; Morales-Quezada, León; Onoda Tomikawa, Luis C.; Onoda Tomikawa, Luis G.; Alfieri, Fabio M.; Filippo, Thais R.; da Rocha, Ivan D.; Neto, Raul Bolliger; Fregni, Felipe; Battistella, Linamara Rizzo

    2016-01-01

    In this large, sham-controlled, randomized trial, we examined the efficacy of the combination of standard treatment and paraspinous lidocaine injection compared with standard therapy alone in subjects with chronic low back pain. There is little research-based evidence for the routine clinical use of paraspinous lidocaine injection for low back pain. A total of 378 subjects with nonspecific chronic low back pain were randomized to 3 groups: paraspinous lidocaine injection, analgesics, and exercises (group 1, LID-INJ); sham paraspinous lidocaine injection, analgesics, and exercises (group 2, SH-INJ); and analgesics and exercises (group 3, STD-TTR). A blinded rater assessed the study outcomes at 3 time points: baseline, after treatment, and after 3 months of follow-up. There were increased frequency of pain responses and better low back functional scores in the LID-INJ group compared with the SH-INJ and STD-TTR groups. These effects remained at the 3-month follow-up but differed between all 3 groups. There were significant changes in pain threshold immediately after treatment, supporting the effects of this intervention in reducing central sensitization. Paraspinous lidocaine injection therapy is not associated with a higher risk of adverse effects compared with conventional treatment and sham injection. Its effects on hyperalgesia might correlate with changes in central sensitization. PMID:26828801

  20. On designing a control system for a new generation of accelerators

    SciTech Connect

    Schaller, S.C.; Schultz, D.E.

    1987-01-01

    A well-conceived plan of attack is essential to the task of designing a control system for a large accelerator. Several aspects of such a plan have been investigated during recent work at LAMPF on design strategies for an Advanced Hadron Facility control system. Aspects discussed in this paper include: identification of requirements, creation and enforcement of standards, interaction with users, consideration of commercial controls products, integration with existing control systems, planning for continual change, and establishment of design reviews. We emphasize the need for the controls group to acquire and integrate accelerator design information from the start of the design process. We suggest that a controls design for a new generation of accelerators be done with a new generation of software tools. 12 refs.

  1. New kind of injection-locked oscillator and its corresponding long-term stability control.

    PubMed

    Hong, Jun; Liu, An; Wang, Xiao-hu; Yao, Sheng-xing; Li, Zu-ling

    2015-09-20

    A new type of opto-electronic hybrid oscillator is proposed for the first time, to the best of our knowledge, and verified by experiments in this paper. Typical electronic oscillator-dielectric resonator oscillator as the first injection source is used to injection lock the first long-fiber loop-based opto-electronic oscillator (OEO); then its output is used to injection lock the second long-fiber opto-electronic oscillator. Using this method, low-phase noise output signal can be obtained. Experiments show that single side-band (SSB) phase noise of a 9.5 GHz oscillation signal at 10 kHz offset frequency decreases from -123 to -135  dBc/Hz after the first injection, then, through the second injection, the SSB phase noise drops down to -146  dBc/Hz. In order to solve the long-term stability problem of the above oscillator, a new stability-control circuit also is designed and verified by experiments. Experiments show that the Allan deviation decreases from 9.0×10(-11) to 2.2×10(-12) during 1 s after the long-term stability-control circuit being used. PMID:26406523

  2. The effectiveness of a double-stem injection valve in controlling combustion in a compression-ignition engine

    NASA Technical Reports Server (NTRS)

    Spanogle, J A; Whitney, E G

    1931-01-01

    An investigation was made to determine to what extent the rates of combustion in a compression-ignition engine can be controlled by varying the rates of fuel injection. The tests showed that the double-stem valve operated satisfactorily under all normal injection conditions; the rate of injection has a definite effect on the rate of combustion; the engine performance with the double-stem valve was inferior to that obtained with a single-stem valve; and the control of injection rates permitted by an injection valve of two stages of discharge is not sufficient to effect the desired rates of combustion.

  3. EMISSION TEST REPORT- FIELD TEST OF CARBON INJECTION FOR MERCURY CONTROL, CAMDEN COUNTY MUNICIPAL WASTE COMBUSTOR

    EPA Science Inventory

    The report gives results of parametric test to evaluate the injection powdered activated carbon to control volatile pollutants in municipal waste combustor (MWC) flue gas. he tests were conducted at a spray dryer absorber/electrostatic precipitator (SD/ESP)-equipped MWC in Camden...

  4. TEST DESIGN FOR ENVIRONMENTAL TECHNOLOGY VERIFICATION (ETV) OF ADD-ON NOX CONTROL UTILIZING OZONE INJECTION

    EPA Science Inventory

    The paper discusses the test design for environmental technology verification (ETV) of add-0n nitrogen oxides (NOx) control utilizing ozone injection. (NOTE: ETV is an EPA-established program to enhance domestic and international market acceptance of new or improved commercially...

  5. EMISSION TEST REPORT - FIELD TEST OF CARBON INJECTION FOR MERCURY CONTROL - CAMDEN COUNTY MUNICIPAL WASTE COMBUSTOR

    EPA Science Inventory

    The report gives results of parametric test to evaluate the injection powdered activated carbon to control volatile pollutants in municipal waste combustor (MWC) flue gas. he tests were conducted at a spray dryer absorber/electrostatic precipitator (SD/ESP)-equipped MWC in Camden...

  6. Initial investigation using statistical process control for quality control of accelerator beam steering

    PubMed Central

    2011-01-01

    Background This study seeks to increase clinical operational efficiency and accelerator beam consistency by retrospectively investigating the application of statistical process control (SPC) to linear accelerator beam steering parameters to determine the utility of such a methodology in detecting changes prior to equipment failure (interlocks actuated). Methods Steering coil currents (SCC) for the transverse and radial planes are set such that a reproducibly useful photon or electron beam is available. SCC are sampled and stored in the control console computer each day during the morning warm-up. The transverse and radial - positioning and angle SCC for photon beam energies were evaluated using average and range (Xbar-R) process control charts (PCC). The weekly average and range values (subgroup n = 5) for each steering coil were used to develop the PCC. SCC from September 2009 (annual calibration) until two weeks following a beam steering failure in June 2010 were evaluated. PCC limits were calculated using the first twenty subgroups. Appropriate action limits were developed using conventional SPC guidelines. Results PCC high-alarm action limit was set at 6 standard deviations from the mean. A value exceeding this limit would require beam scanning and evaluation by the physicist and engineer. Two low alarms were used to indicate negative trends. Alarms received following establishment of limits (week 20) are indicative of a non-random cause for deviation (Xbar chart) and/or an uncontrolled process (R chart). Transverse angle SCC for 6 MV and 15 MV indicated a high-alarm 90 and 108 days prior to equipment failure respectively. A downward trend in this parameter continued, with high-alarm, until failure. Transverse position and radial angle SCC for 6 and 15 MV indicated low-alarms starting as early as 124 and 116 days prior to failure, respectively. Conclusion Radiotherapy clinical efficiency and accelerator beam consistency may be improved by instituting SPC

  7. Magnetically Controlled Optical Plasma Waveguide for Electron Acceleration

    SciTech Connect

    Pollock, B. B.; Davis, P.; Divol, L.; Glenzer, S. H.; Palastro, J. P.; Price, D.; Froula, D. H.; Tynan, G. R.

    2009-01-22

    In order to produce multi-Gev electrons from Laser Wakefield Accelerators, we present a technique to guide high power laser beams through underdense plasma. Experimental results from the Jupiter Laser Facility at the Lawrence Livermore National Laboratory that show density channels with minimum plasma densities below 5x10{sup 17} cm{sup -3} are presented. These results are obtained using an external magnetic field (<5 T) to limit the radial heat flux from a pre-forming laser beam. The resulting increased plasma pressure gradient produces a parabolic density gradient which is tunable by changing the external magnetic field strength. These results are compared with 1-D hydrodynamic simulations, while quasi-static kinetic simulations show that for these channel conditions 90% of the energy in a 150 TW short pulse beam is guided over 5 cm and predict electron energy gains of 3 GeV.

  8. Magnetically Controlled Optical Plasma Waveguide for Electron Acceleration

    SciTech Connect

    Pollock, B B; Froula, D H; Tynan, G R; Divol, L; Davis, P; Palastro, J P; Price, D; Glenzer, S H

    2008-08-28

    In order to produce multi-Gev electrons from Laser Wakefield Accelerators, we present a technique to guide high power laser beams through underdense plasma. Experimental results from the Jupiter Laser Facility at the Lawrence Livermore National Laboratory that show density channels with minimum plasma densities below 5 x 10{sup 17} cm{sup -3} are presented. These results are obtained using an external magnetic field (<5 T) to limit the radial heat flux from a pre-forming laser beam. The resulting increased plasma pressure gradient produces a parabolic density gradient which is tunable by changing the external magnetic field strength. These results are compared with 1-D hydrodynamic simulations, while quasi-static kinetic simulations show that for these channel conditions 90% of the energy in a 150 TW short pulse beam is guided over 5 cm and predict electron energy gains of 3 GeV.

  9. Intensity control in experimental rooms of the GANIL accelerator

    NASA Astrophysics Data System (ADS)

    Courtois, C.; Jamet, C.; Le Coz, W.; Ledu, G.

    2014-12-01

    The safety re-examination of existing GANIL (the French national heavy-ion accelerator facility) installations requires the implementation of a safety system which makes possible the monitoring of beam intensities sent in the experimental rooms. The aim is to demonstrate that beam intensities stay below the authorized limits. The required characteristics should enable the measurement, by a non-interceptive method, of beam intensities from 5 nA to 5 μA with a maximum uncertainty of ±5%, independently of the frequency and the beam energy. After a comparative study, two high frequency diagnostics were selected: the capacitive Pick-Up (PU) and the Fast Current Transformer (FCT). Based on results of simulation, laboratory tests and machine studies, this paper discusses all the considerations required to deliver accurate results from PU and FCT measurement of ion beams.

  10. Acceleration of onset of collagen-induced arthritis by intra-articular injection of tumour necrosis factor or transforming growth factor-beta.

    PubMed Central

    Cooper, W O; Fava, R A; Gates, C A; Cremer, M A; Townes, A S

    1992-01-01

    We examined whether tumour necrosis factor (TNF) or transforming growth factor-beta 1 (TGF-beta 1) could alter the course of collagen-induced arthritis (CIA). Injection of 100 ng TNF or 500 ng TGF-beta 1 into ankle joints of normal rats induced a very limited inflammatory response, observable only upon histological analysis. However, when injected into ankle joints of rats 9 days after immunization with bovine type II collagen (CII), identical doses of TNF or TGF-beta 1 induced a sustained, clinically obvious inflammation and oedema that began within 8 h on average, as compared to 90 h in CII-immunized control rats given no injections or intra-articular injections of buffer. The incidence of arthritis at 2 weeks post-immunization was 100% for TNF-injected hindpaws, compared with 55% for the control groups, a statistically significant difference. In rats passively immunized with a subarthritic dose of affinity purified antibody to rat-CII, intra-articular injection of 100 ng TNF or 500 ng of TGF-beta 1 also induced intense, though transient arthritis. The rapid proinflammatory effects in CIA described in this study and the synergy demonstrated between anti-CII IgG and either cytokine, suggest that these cytokines can participate locally in the pathogenesis of arthritis. PMID:1638767

  11. Induction of electron injection and betatron oscillation in a plasma-waveguide-based laser wakefield accelerator by modification of waveguide structure

    SciTech Connect

    Ho, Y.-C.; Hung, T.-S.; Chen, W.-H.; Jhou, J.-G.; Qayyum, H.; Chen, S.-Y.; Chu, H.-H.; Lin, J.-Y.; Wang, J.

    2013-08-15

    By adding a transverse heater pulse into the axicon ignitor-heater scheme for producing a plasma waveguide, a variable three-dimensionally structured plasma waveguide can be fabricated. With this technique, electron injection in a plasma-waveguide-based laser wakefield accelerator was achieved and resulted in production of a quasi-monoenergetic electron beam. The injection was correlated with a section of expanding cross-section in the plasma waveguide. Moreover, the intensity of the X-ray beam produced by the electron bunch in betatron oscillation was greatly enhanced with a transversely shifted section in the plasma waveguide. The technique opens a route to a compact hard-X-ray pulse source.

  12. Transverse acceptance calculation for continuous ion beam injection into the electron beam ion trap charge breeder of the ReA post-accelerator

    NASA Astrophysics Data System (ADS)

    Kittimanapun, K.; Baumann, T. M.; Lapierre, A.; Schwarz, S.; Bollen, G.

    2015-11-01

    The ReA post-accelerator at the National Superconducting Cyclotron Laboratory (NSCL) employs an electron beam ion trap (EBIT) as a charge breeder. A Monte-Carlo simulation code was developed to calculate the transverse acceptance phase space of the EBIT for continuously injected ion beams and to determine the capture efficiency in dependence of the transverse beam emittance. For this purpose, the code records the position and time of changes in charge state of injected ions, leading either to capture or loss of ions. To benchmark and validate the code, calculated capture efficiencies were compared with results from a geometrical model and measurements. The results of the code agree with the experimental findings within a few 10%. The code predicts a maximum total capture efficiency of 50% for EBIT parameters readily achievable and an efficiency of up to 80% for an electron beam current density of 1900 A/cm2.

  13. Direct observation of the phase space footprint of a painting injection in the Rapid Cycling Synchrotron at the Japan Proton Accelerator Research Complex

    NASA Astrophysics Data System (ADS)

    Saha, P. K.; Shobuda, Y.; Hotchi, H.; Hayashi, N.; Takayanagi, T.; Harada, H.; Irie, Y.

    2009-04-01

    The 3 GeV Rapid Cycling Synchrotron (RCS) at Japan Proton Accelerator Research Complex is nearly at the operational stage with regard to the beam commissioning aspects. Recently, the design painting injection study has been commenced with the aim of high output beam power at the extraction. In order to observe the phase space footprint of the painting injection, a method was developed utilizing a beam position monitor (BPM) in the so-called single pass mode. The turn-by-turn phase space coordinates of the circulating beam directly measured using a pair of BPMs entirely positioned in drift space, and the calculated transfer matrices from the injection point to the pair of BPMs with several successive turns were used together in order to obtain the phase space footprint of the painting injection. There are two such pairs of BPMs placed in two different locations in the RCS, the results from which both agreed and were quite consistent with what was expected.

  14. Attack methodology Analysis: SQL Injection Attacks and Their Applicability to Control Systems

    SciTech Connect

    Bri Rolston

    2005-09-01

    Database applications have become a core component in control systems and their associated record keeping utilities. Traditional security models attempt to secure systems by isolating core software components and concentrating security efforts against threats specific to those computers or software components. Database security within control systems follows these models by using generally independent systems that rely on one another for proper functionality. The high level of reliance between the two systems creates an expanded threat surface. To understand the scope of a threat surface, all segments of the control system, with an emphasis on entry points, must be examined. The communication link between data and decision layers is the primary attack surface for SQL injection. This paper facilitates understanding what SQL injection is and why it is a significant threat to control system environments.

  15. Comparing the performance of injection and infiltration in controlling seawater intrusion

    NASA Astrophysics Data System (ADS)

    Lu, C.

    2015-12-01

    Among various strategies introduced for controlling seawater intrusion, artificial recharge through either well injection or pond infiltration is used most commonly in practice. In this study, we compare the performance of well injection and pond infiltration in controlling seawater intrusion through two scenario groups. First, a single injection well is compared with an elliptical infiltration pond by assuming that the pond and the well share the same location and the recharge rate. Second, an injection-extraction well pair system is compared with an elliptical pond infiltration-well extraction system by assuming the same condition as in the first scenario and the same location of the extraction well. The quantitative indicators including the interface toe location, saltwater volume, and the maximum net extraction rate are derived analytically using the potential theory. By comparing the two schemes in the first scenario group, it is found that the infiltration pond significantly outperforms the injection well under the condition that the major semi-axis of the ellipse is along the coastline. Importantly, a critical location of the infiltration pond/injection well is found, under which the maximum reduction in the saltwater volume is achieved. The study of the second scenario suggests that the pond-well system significantly outperforms a well-pair system in terms of the maximum net extraction rate, if the major semi-axis of the ellipse is along the coastline. Sensitivity analysis shows that the shape of the elliptical pond (i.e., the ratio of the major semi-axis to the minor semi-axis) is a key design parameter controlling its performance. The analytical analysis in this study provides initial guidance for practitioners when using the aquifer recharge strategy to restore a salinized coastal aquifer.

  16. System modeling for the longitudinal beam dynamics control problem in heavy ion induction accelerators

    SciTech Connect

    Payne, A.N.

    1993-05-17

    We address the problem of developing system models that are suitable for studying the control of the longitudinal beam dynamics in induction accelerators for heavy ions. In particular, we present the preliminary results of our efforts to devise a general framework for building detailed, integrated models of accelerator systems consisting of pulsed power modular circuits, induction cells, beam dynamics, and control system elements. Such a framework will permit us to analyze and design the pulsed power modulators and the control systems required to effect precise control over the longitudinal beam dynamics.

  17. The importance of energetic particle injections and cross-energy and -species interactions to the acceleration and loss of relativistic electrons in Earth's outer radiation belt (invited talk)

    NASA Astrophysics Data System (ADS)

    Turner, Drew; Gkioulidou, Matina; Ukhorskiy, Aleksandr; Gabrielse, Christine; Runov, Andrei; Angelopoulos, Vassilis

    2014-05-01

    Earth's radiation belts provide a natural laboratory to study a variety of physical mechanisms important for understanding the nature of energetic particles throughout the Universe. The outer electron belt is a particularly variable population, with drastic changes in relativistic electron intensities occurring on a variety of timescales ranging from seconds to decades. Outer belt variability ultimately results from the complex interplay between different source, loss, and transport processes, and all of these processes are related to the dynamics of the inner magnetosphere. Currently, an unprecedented number of spacecraft are providing in situ observations of the inner magnetospheric environment, including missions such as NASA's THEMIS and Van Allen Probes and ESA's Cluster and operational monitors such as NOAA's GOES and POES constellations. From a sampling of case studies using multi-point observations, we present examples showcasing the significant importance of two processes to outer belt dynamics: energetic particle injections and wave-particle interactions. Energetic particle injections are transient events that tie the inner magnetosphere to the near-Earth magnetotail; they involve the rapid inward transport of plasmasheet particles into the trapping zone in the inner magnetosphere. We briefly review key concepts and present new evidence from Van Allen Probes, GOES, and THEMIS of how these injections provide: 1. the seed population of electrons that are subsequently accelerated locally to relativistic energies in the outer belt and 2. the source populations of ions and electrons that produce a variety of ULF and VLF waves, which are also important for driving outer belt dynamics via wave-particle interactions. Cases of electron acceleration by chorus waves, losses by plasmaspheric hiss and EMIC waves, and radial transport driven by ULF waves will also be presented. Finally, we discuss the implications of this developing picture of the system, namely how

  18. KEK digital accelerator

    NASA Astrophysics Data System (ADS)

    Iwashita, T.; Adachi, T.; Takayama, K.; Leo, K. W.; Arai, T.; Arakida, Y.; Hashimoto, M.; Kadokura, E.; Kawai, M.; Kawakubo, T.; Kubo, Tomio; Koyama, K.; Nakanishi, H.; Okazaki, K.; Okamura, K.; Someya, H.; Takagi, A.; Tokuchi, A.; Wake, M.

    2011-07-01

    The High Energy Accelerator Research Organization KEK digital accelerator (KEK-DA) is a renovation of the KEK 500 MeV booster proton synchrotron, which was shut down in 2006. The existing 40 MeV drift tube linac and rf cavities have been replaced by an electron cyclotron resonance (ECR) ion source embedded in a 200 kV high-voltage terminal and induction acceleration cells, respectively. A DA is, in principle, capable of accelerating any species of ion in all possible charge states. The KEK-DA is characterized by specific accelerator components such as a permanent magnet X-band ECR ion source, a low-energy transport line, an electrostatic injection kicker, an extraction septum magnet operated in air, combined-function main magnets, and an induction acceleration system. The induction acceleration method, integrating modern pulse power technology and state-of-art digital control, is crucial for the rapid-cycle KEK-DA. The key issues of beam dynamics associated with low-energy injection of heavy ions are beam loss caused by electron capture and stripping as results of the interaction with residual gas molecules and the closed orbit distortion resulting from relatively high remanent fields in the bending magnets. Attractive applications of this accelerator in materials and biological sciences are discussed.

  19. Injectable thermosensitive chitosan hydrogels with controlled gelation kinetics and enhanced mechanical resistance.

    PubMed

    Assaad, Elias; Maire, Marion; Lerouge, Sophie

    2015-10-01

    The use of injectable hydrogels is presently limited by the difficulty to achieve rapid gelation, high mechanical resistance and excellent cytocompatibility. In our study, high-strength injectable thermosensitive hydrogels of unmodified chitosan (CH) were obtained by combining sodium hydrogen carbonate (SHC) with phosphate buffer (PB) or beta-glycerophosphate (BGP) as gelling agents. A synergic effect led to the acceleration of gelation and a remarkable improvement of the storage modulus (G') of the hydrogels. Furthermore, the new hydrogels exhibited drastically enhanced Young moduli and resistance in compression as compared to conventional hydrogels prepared with BGP, PB or their combination. This was achieved while reducing the total salt concentration in the hydrogels. The gelation was rapid and the hydrogels presented porous structures and physiological pH, and did not show any cytotoxicity to L929 fibroblast cells in vitro. Overall, these new hydrogels provide interesting alternatives for use as blood vessel embolizing agents or as injectable scaffolds for drug delivery and/or cell seeding in tissue engineering strategies. PMID:26076604

  20. Surfactant enhanced injectivity of xanthan mobility control solutions for tertiary oil recovery

    SciTech Connect

    Miller, J.W.; Tate, B.E.

    1983-09-27

    An aqueous mobility control solution for tertiary oil recovery from saline oil fields comprises from about 200 to 2000 ppm xanthan biopolymer in the form of clean, unreconstituted fermentation broth and from about 20 to 200 ppm of a selected water-soluble polyglycol-based surfactant. A process for tertiary oil recovery which comprises the injection of the mobility control solution into saline oil-bearing subterranian formations is also disclosed.

  1. Low-level RF control system issues for an ADTT accelerator

    SciTech Connect

    Ziomek, C.D.; Regan, A.H.; Lynch, M.T.; Bowling, P.S.

    1994-09-01

    The RF control system for a charged-particle accelerator must maintain the correct amplitude and phase of RF field inside the accelerator cavity in the presence of perturbations, noises, and time varying system components. For an accelerator with heavy beam-loading, fluctuations in the beam current cause large perturbations to the RF field amplitude and phase that must be corrected by the RF control system. The ADTT applications require a high-current, heavily beam-loaded, continuous-wave (CW) accelerator. Additional concerns created by the CW operation include system start-up, beam interruption, and fault recovery. Also, the RF control system for an ADTT facility must include sophisticated automation to reduce the operator interaction and support. This paper describes an RF control system design that addresses these various issues by evaluation a combination of feedback and feed forward control techniques. Experience from the high-current Ground Test Accelerator (GTA) is drawn upon for this RF control system design. Comprehensive computer modeling with the Matrix{sub x} software has been used to predict the performance of this RF control system.

  2. Low-level RF control system issues for an ADTT accelerator

    SciTech Connect

    Ziomek, C. D.; Regan, A. H.; Lynch, M. T.; Bowling, P. S.

    1995-09-15

    The RF control system for a charged-particle accelerator must maintain the correct amplitude and phase of the RF field inside the accelerator cavity in the presence of perturbations, noises, and time varying system components. For an accelerator with heavy beam-loading, fluctuations in the beam current cause large perturbations to the RF field amplitude and phase that must be corrected by the RF control system. The ADTT applications require a high-current, heavily beam-loaded, continuous-wave (CW) accelerator. Additional concerns created by the CW operation include system start-up, beam interruption, and fault recovery. Also, the RF control system for an ADTT facility must include sophisticated automation to reduce the operator interaction and support. This paper describes an RF control system design that addresses these various issues by evaluation a combination of feedback and feedforward control techniques. Experience from the high-current Ground Test Accelerator (GTA) is drawn upon for this RF control system design. Comprehensive computer modeling with the Matrixx software has been used to predict the performance of this RF control system.

  3. Control of linear accelerator noise in the Los Alamos free-electron laser (FEL)

    SciTech Connect

    Lynch, M.T.

    1986-01-01

    The Los Alamos FEL requires tight control of the amplitudes and phases of the fields in two linear accelerator tanks to obtain stable lasing. The accelerator control loops must establish constant, stable, repeatable amplitudes and phases of the rf fields and must have excellent bandwidth to control high-frequency noise components. A model of the feedback loops has been developed that agrees well with measurements and allows easy substitution of components and circuits, thus reducing breadboarding requirements. The model permits both frequency and time-domain analysis. This paper describes the accelerator control scheme and our model and discusses the control of noise in feedback loops, showing how low-frequency-noise components (errors) can be corrected, but high-frequency-noise components (errors) are actually amplified by the feedback circuit. Measurements of noise in both open- and closed-loop modes are shown and comparison is made with results from the model calculations.

  4. Controlled release of protein from biodegradable multi-sensitive injectable poly(ether-urethane) hydrogel.

    PubMed

    Li, Xiaomeng; Wang, Yangyun; Chen, Jiaming; Wang, Yinong; Ma, Jianbiao; Wu, Guolin

    2014-03-12

    The synthesis and characterization of multi-sensitive polymers for use as injectable hydrogels for controlled protein/drug delivery is reported. A series of biodegradable multi-sensitive poly(ether-urethane)s were prepared through a simple one-pot condensation of poly(ethylene glycol), 2,2'-dithiodiethanol, N-methyldiethanolamine, and hexamethylene diisocyanate. The sol-gel phase transition behaviors of the obtained copolymers were investigated. Experimental results showed that the aqueous medium comprising the multi-segment copolymers underwent a sol-to-gel phase transition with increasing temperature and pH. At a certain concentration, the copolymer solution could immediately change to a gel under physiological conditions (37 °C and pH 7.4), indicating their suitability as in situ injectable hydrogels in vivo. Insulin was used as a model protein drug for evaluation of the injectable hydrogels as a site-specific drug delivery system. The controlled release of insulin from the hydrogel devices was demonstrated by degradation of the copolymer, which is modulated via the 2,2'-dithiodiethanol content in the poly(ether-urethane)s. These hydrogels having multi-responsive properties may prove to be promising candidates for injectable and controllable protein drug delivery devices. PMID:24460175

  5. A harmonic injection SPWM method for the high-responsive PMSM control system

    NASA Astrophysics Data System (ADS)

    Lei, Wang; Shuanghui, Hao; Minghui, Hao; Baoyu, Song

    2016-01-01

    In a permanent magnet synchronous motor (PMSM) control system, usually, the phase voltage instruction is limited independently to prevent a three-phase pulse width modulation (PWM) wave from overflowing. This method decreases the efficiency of the bus voltage and causes voltage vector direction errors. To solve these problems, we propose a harmonic injection sinusoidal pulse-width modulation (SPWM). This method uses harmonic injected sinusoidal PWM to improve the utilisation ratio of the bus voltage, and consequently improve system performance. In this paper, we analyse the problem in terms of potential difference. The simulation results show that the proposed method can increase the utilisation ratio of the bus voltage up to 15.4%, and the voltage vector mode obtained with the proposed algorithm is larger than that obtained with the conventional one. The method with harmonic injection consequently improves current response, without affecting voltage vector accuracy. The experiment results validate the proposed method.

  6. Field Testing of Activated Carbon Injection Options for Mercury Control at TXU's Big Brown Station

    SciTech Connect

    John Pavlish; Jeffrey Thompson; Christopher Martin; Mark Musich; Lucinda Hamre

    2009-01-07

    The primary objective of the project was to evaluate the long-term feasibility of using activated carbon injection (ACI) options to effectively reduce mercury emissions from Texas electric generation plants in which a blend of lignite and subbituminous coal is fired. Field testing of ACI options was performed on one-quarter of Unit 2 at TXU's Big Brown Steam Electric Station. Unit 2 has a design output of 600 MW and burns a blend of 70% Texas Gulf Coast lignite and 30% subbituminous Powder River Basin coal. Big Brown employs a COHPAC configuration, i.e., high air-to-cloth baghouses following cold-side electrostatic precipitators (ESPs), for particulate control. When sorbent injection is added between the ESP and the baghouse, the combined technology is referred to as TOXECON{trademark} and is patented by the Electric Power Research Institute in the United States. Key benefits of the TOXECON configuration include better mass transfer characteristics of a fabric filter compared to an ESP for mercury capture and contamination of only a small percentage of the fly ash with AC. The field testing consisted of a baseline sampling period, a parametric screening of three sorbent injection options, and a month long test with a single mercury control technology. During the baseline sampling, native mercury removal was observed to be less than 10%. Parametric testing was conducted for three sorbent injection options: injection of standard AC alone; injection of an EERC sorbent enhancement additive, SEA4, with ACI; and injection of an EERC enhanced AC. Injection rates were determined for all of the options to achieve the minimum target of 55% mercury removal as well as for higher removals approaching 90%. Some of the higher injection rates were not sustainable because of increased differential pressure across the test baghouse module. After completion of the parametric testing, a month long test was conducted using the enhanced AC at a nominal rate of 1.5 lb/Macf. During the

  7. Interdiffusion-controlled Kondo suppression of injection efficiency in metallic nonlocal spin valves

    NASA Astrophysics Data System (ADS)

    O'Brien, L.; Spivak, D.; Jeong, J. S.; Mkhoyan, K. A.; Crowell, P. A.; Leighton, C.

    2016-01-01

    Nonlocal spin valves (NLSVs) generate pure spin currents, providing unique insight into spin injection and relaxation at the nanoscale. Recently it was shown that the puzzling low temperature nonmonotonicity of the spin accumulation in all-metal NLSVs occurs due to a manifestation of the Kondo effect arising from dilute local-moment-forming impurities in the nonmagnetic material. Here it is demonstrated that precise control over interdiffusion in Fe/Cu NLSVs via thermal annealing can induce dramatic increases in this Kondo suppression of injection efficiency, observation of injector/detector separation-dependent Kondo effects in both charge and spin channels simultaneously, and, in the limit of large interdiffusion, complete breakdown of standard Valet-Fert-based models. The Kondo effect in the charge channel enables extraction of the exact interdiffusion profile, quantifying the influence of local moment density on the injection efficiency and presenting a well-posed challenge to theory.

  8. GENERATION AND CONTROL OF HIGH PRECISION BEAMS AT LEPTON ACCELERATORS

    SciTech Connect

    Yu-Chiu Chao

    2007-06-25

    Parity violation experiments require precision manipulation of helicity-correlated beam coordinates on target at the nm/nrad-level. Achieving this unprecedented level of control requires a detailed understanding of the particle optics and careful tuning of the beam transport to keep anomalies from compromising the design adiabatic damping. Such efforts are often hindered by machine configuration and instrumentation limitations at the low energy end. A technique has been developed at CEBAF including high precision measurements, Mathematica-based analysis for obtaining corrective solutions, and control hardware/software developments for realizing such level of control at energies up to 5 GeV.

  9. ACCELERATORS Control system for the CSNS ion source test stand

    NASA Astrophysics Data System (ADS)

    Lu, Yan-Hua; Li, Gang; Ouyang, Hua-Fu

    2010-12-01

    A penning plasma surface H- ion source test stand for the CSNS has just been constructed at the IHEP. In order to achieve a safe and reliable system, nearly all devices of the ion source are designed to have the capability of both local and remote operation function. The control system consists of PLCs and EPICS real-time software tools separately serving device control and monitoring, PLC integration and OPI support. This paper summarizes the hardware and software implementation satisfying the requirements of the ion source control system.

  10. Acupuncture point injection treatment of primary dysmenorrhoea: a randomised, double blind, controlled study

    PubMed Central

    Wade, C; Wang, L; Zhao, W J; Cardini, F; Kronenberg, F; Gui, S Q; Ying, Z; Zhao, N Q; Chao, M T; Yu, J

    2016-01-01

    Objective To determine if injection of vitamin K3 in an acupuncture point is optimal for the treatment of primary dysmenorrhoea, when compared with 2 other injection treatments. Setting A Menstrual Disorder Centre at a public hospital in Shanghai, China. Participants Chinese women aged 14–25 years with severe primary dysmenorrhoea for at least 6 months not relieved by any other treatment were recruited. Exclusion criteria were the use of oral contraceptives, intrauterine devices or anticoagulant drugs, pregnancy, history of abdominal surgery, participation in other therapies for pain and diagnosis of secondary dysmenorrhoea. Eighty patients with primary dysmenorrhoea, as defined on a 4-grade scale, completed the study. Two patients withdrew after randomisation. Interventions A double-blind, double-dummy, randomised controlled trial compared vitamin K3 acupuncture point injection to saline acupuncture point injection and vitamin K3 deep muscle injection. Patients in each group received 3 injections at a single treatment visit. Primary and secondary outcome measures The primary outcome was the difference in subjective perception of pain as measured by an 11 unit Numeric Rating Scale (NRS). Secondary measurements were Cox Pain Intensity and Duration scales and the consumption of analgesic tablets before and after treatment and during 6 following cycles. Results Patients in all 3 groups experienced pain relief from the injection treatments. Differences in NRS measured mean pain scores between the 2 active control groups were less than 1 unit (−0.71, CI −1.37 to −0.05) and not significant, but the differences in average scores between the treatment hypothesised to be optimal and both active control groups (1.11, CI 0.45 to 1.78) and (1.82, CI 1.45 to 2.49) were statistically significant in adjusted mixed-effects models. Menstrual distress and use of analgesics were diminished for 6 months post-treatment. Conclusions Acupuncture point injection of

  11. Single Cell Transfection through Precise Microinjection with Quantitatively Controlled Injection Volumes

    PubMed Central

    Chow, Yu Ting; Chen, Shuxun; Wang, Ran; Liu, Chichi; Kong, Chi-wing; Li, Ronald A.; Cheng, Shuk Han; Sun, Dong

    2016-01-01

    Cell transfection is a technique wherein foreign genetic molecules are delivered into cells. To elucidate distinct responses during cell genetic modification, methods to achieve transfection at the single-cell level are of great value. Herein, we developed an automated micropipette-based quantitative microinjection technology that can deliver precise amounts of materials into cells. The developed microinjection system achieved precise single-cell microinjection by pre-patterning cells in an array and controlling the amount of substance delivered based on injection pressure and time. The precision of the proposed injection technique was examined by comparing the fluorescence intensities of fluorescent dye droplets with a standard concentration and water droplets with a known injection amount of the dye in oil. Injection of synthetic modified mRNA (modRNA) encoding green fluorescence proteins or a cocktail of plasmids encoding green and red fluorescence proteins into human foreskin fibroblast cells demonstrated that the resulting green fluorescence intensity or green/red fluorescence intensity ratio were well correlated with the amount of genetic material injected into the cells. Single-cell transfection via the developed microinjection technique will be of particular use in cases where cell transfection is challenging and genetically modified of selected cells are desired. PMID:27067121

  12. Single Cell Transfection through Precise Microinjection with Quantitatively Controlled Injection Volumes.

    PubMed

    Chow, Yu Ting; Chen, Shuxun; Wang, Ran; Liu, Chichi; Kong, Chi-Wing; Li, Ronald A; Cheng, Shuk Han; Sun, Dong

    2016-01-01

    Cell transfection is a technique wherein foreign genetic molecules are delivered into cells. To elucidate distinct responses during cell genetic modification, methods to achieve transfection at the single-cell level are of great value. Herein, we developed an automated micropipette-based quantitative microinjection technology that can deliver precise amounts of materials into cells. The developed microinjection system achieved precise single-cell microinjection by pre-patterning cells in an array and controlling the amount of substance delivered based on injection pressure and time. The precision of the proposed injection technique was examined by comparing the fluorescence intensities of fluorescent dye droplets with a standard concentration and water droplets with a known injection amount of the dye in oil. Injection of synthetic modified mRNA (modRNA) encoding green fluorescence proteins or a cocktail of plasmids encoding green and red fluorescence proteins into human foreskin fibroblast cells demonstrated that the resulting green fluorescence intensity or green/red fluorescence intensity ratio were well correlated with the amount of genetic material injected into the cells. Single-cell transfection via the developed microinjection technique will be of particular use in cases where cell transfection is challenging and genetically modified of selected cells are desired. PMID:27067121

  13. Single Cell Transfection through Precise Microinjection with Quantitatively Controlled Injection Volumes

    NASA Astrophysics Data System (ADS)

    Chow, Yu Ting; Chen, Shuxun; Wang, Ran; Liu, Chichi; Kong, Chi-Wing; Li, Ronald A.; Cheng, Shuk Han; Sun, Dong

    2016-04-01

    Cell transfection is a technique wherein foreign genetic molecules are delivered into cells. To elucidate distinct responses during cell genetic modification, methods to achieve transfection at the single-cell level are of great value. Herein, we developed an automated micropipette-based quantitative microinjection technology that can deliver precise amounts of materials into cells. The developed microinjection system achieved precise single-cell microinjection by pre-patterning cells in an array and controlling the amount of substance delivered based on injection pressure and time. The precision of the proposed injection technique was examined by comparing the fluorescence intensities of fluorescent dye droplets with a standard concentration and water droplets with a known injection amount of the dye in oil. Injection of synthetic modified mRNA (modRNA) encoding green fluorescence proteins or a cocktail of plasmids encoding green and red fluorescence proteins into human foreskin fibroblast cells demonstrated that the resulting green fluorescence intensity or green/red fluorescence intensity ratio were well correlated with the amount of genetic material injected into the cells. Single-cell transfection via the developed microinjection technique will be of particular use in cases where cell transfection is challenging and genetically modified of selected cells are desired.

  14. Lime Juice and Vinegar Injections as a Cheap and Natural Alternative to Control COTS Outbreaks.

    PubMed

    Moutardier, Grégoire; Gereva, Sompert; Mills, Suzanne C; Adjeroud, Mehdi; Beldade, Ricardo; Ham, Jayven; Kaku, Rocky; Dumas, Pascal

    2015-01-01

    Outbreaks of the corallivorous crown-of-thorns seastar Acanthaster planci (COTS) represent one of the greatest disturbances to coral reef ecosystems in the Indo-Pacific, affecting not only coral reefs but also the coastal communities which rely on their resources. While injection approaches are increasingly used in an attempt to control COTS densities, most of them display severe drawbacks including logistical challenges, high residual environmental impacts or low cost-effectiveness. We tested a new alternative control method based upon acidic injections of cheap, 100% natural products. We investigated the lethal doses, intra- and inter-specific disease transmission and immune responses of COTS when injected with fresh lime juice (extracted from local Citrus arantifolia) and white spirit vinegar. High COTS mortality was achieved with small volumes: 10-20 ml per seastar induced death in 89%/97% of injected specimens after an average 34.3 h/29.8 h for lime juice and vinegar respectively. Highest efficiency was reached for both solutions with double shots of (2 × 10 ml) in two different areas on the body: 100% mortality occurred within 12-24 h, which is similar or faster compared with other current injection methods. Multiple immune measures suggested that death was very likely caused by pH stress from the acidic solutions rather than a bacterial infection. Contagion to either conspecifics or a variety of other reef species was not observed, even at COTS densities 15 times higher than the highest naturally reported. 10 to 20 l lime juice/vinegar could kill up to a thousand COTS at a cost of less than 0.05 USD per specimen; no permits or special handling procedures are required. We conclude that injections of lime juice and vinegar offer great advantages when compared to current best practises and constitute a cheap and natural option for all reefs affected by COTS. PMID:26356840

  15. Lime Juice and Vinegar Injections as a Cheap and Natural Alternative to Control COTS Outbreaks

    PubMed Central

    Moutardier, Grégoire; Gereva, Sompert; Mills, Suzanne C.; Adjeroud, Mehdi; Beldade, Ricardo; Ham, Jayven; Kaku, Rocky; Dumas, Pascal

    2015-01-01

    Outbreaks of the corallivorous crown-of-thorns seastar Acanthaster planci (COTS) represent one of the greatest disturbances to coral reef ecosystems in the Indo-Pacific, affecting not only coral reefs but also the coastal communities which rely on their resources. While injection approaches are increasingly used in an attempt to control COTS densities, most of them display severe drawbacks including logistical challenges, high residual environmental impacts or low cost-effectiveness. We tested a new alternative control method based upon acidic injections of cheap, 100% natural products. We investigated the lethal doses, intra- and inter-specific disease transmission and immune responses of COTS when injected with fresh lime juice (extracted from local Citrus arantifolia) and white spirit vinegar. High COTS mortality was achieved with small volumes: 10–20 ml per seastar induced death in 89%/97% of injected specimens after an average 34.3 h/29.8 h for lime juice and vinegar respectively. Highest efficiency was reached for both solutions with double shots of (2 × 10 ml) in two different areas on the body: 100% mortality occurred within 12–24 h, which is similar or faster compared with other current injection methods. Multiple immune measures suggested that death was very likely caused by pH stress from the acidic solutions rather than a bacterial infection. Contagion to either conspecifics or a variety of other reef species was not observed, even at COTS densities 15 times higher than the highest naturally reported. 10 to 20 l lime juice/vinegar could kill up to a thousand COTS at a cost of less than 0.05 USD per specimen; no permits or special handling procedures are required. We conclude that injections of lime juice and vinegar offer great advantages when compared to current best practises and constitute a cheap and natural option for all reefs affected by COTS. PMID:26356840

  16. A randomised controlled comparison of injection, thermal, and mechanical endoscopic methods of haemostasis on mesenteric vessels

    PubMed Central

    Hepworth, C; Kadirkamanathan, S; Gong, F; Swain, C

    1998-01-01

    Background and aims—A randomised controlled comparison of haemostatic efficacy of mechanical, injection, and thermal methods of haemostasis was undertaken using canine mesenteric vessels to test the hypothesis that mechanical methods of haemostasis are more effective in controlling haemorrhage than injection or thermal methods. The diameter of arteries in human bleeding ulcers measures up to 3.45 mm; mesenteric vessels up to 5 mm were therefore studied. 
Methods—Mesenteric vessels were randomised to treatment with injection sclerotherapy (adrenaline and ethanolamine), bipolar diathermy, or mechanical methods (band, clips, sewing machine, endoloops). The vessels were severed and haemostasis recorded. 
Results—Injection sclerotherapy and clips failed to stop bleeding from vessels of 1 mm (n=20) and 2 mm (n=20). Bipolar diathermy was effective on 8/10 vessels of 2 mm but failed on 3 mm vessels (n=5). Unstretched elastic bands succeeded on 13/15 vessels of 2 mm but on only 3/10 vessels of 3 mm. The sewing machine achieved haemostasis on 8/10 vessels of 4 mm but failed on 5 mm vessels (n=5); endoloops were effective on all 5 mm vessels (n=5). 
Conclusions—Only mechanical methods were effective on vessels greater than 2 mm in diameter. Some mechanical methods (banding and clips) were less effective than expected and need modification. Thermal and (effective) mechanical methods were significantly (p<0.01) more effective than injection sclerotherapy. The most effective mechanical methods were significantly more effective (p<0.01) than thermal or injection on vessels greater than 2mm. 

 Keywords: endoscopic haemostasis; mesenteric vessels PMID:9616305

  17. Injection molding simulation with variothermal mold temperature control of highly filled polyphenylene sulfide

    NASA Astrophysics Data System (ADS)

    Birkholz, A.; Tschiersky, M.; Wortberg, J.

    2015-05-01

    For the installation of a fuel cell stack to convert chemical energy into electricity it is common to apply bipolar plates to separate and distribute reaction gases and cooling agents. For reducing manufacturing costs of bipolar plates a fully automated injection molding process is examined. The high performance thermoplastic matrix material, polyphenylene sulfide (PPS), defies against the chemical setting and the operation temperature up to 200 °C. To adjust also high electrical and thermal conductivity, PPS is highly filled with various carbon fillers up to an amount of 65 percentage by volume. In the first step two different structural plates (one-sided) with three different gate heights and molds are designed according to the characteristics of a bipolar plate. To cope with the approach that this plate should be producible on standard injection molding machines with variothermal mold temperature control, injection molding simulation is used. Additionally, the simulation should allow to formulate a quality prediction model, which is transferrable to bipolar plates. Obviously, the basis for a precise simulation output is an accurate description of the material properties and behavior of the highly filled compound. This, the design of the structural plate and mold and the optimization via simulation is presented, as well. The influence of the injection molding process parameters, e.g. injection time, cycle times, packing pressure, mold temperature, and melt temperature on the form filling have been simulated to determine optimal process conditions. With the aid of the simulation and the variothermal mold temperature control it was possible to reduce the required melt temperature below the decomposition temperature of PPS. Thereby, hazardous decomposition products as hydrogen sulfide are obviated. Thus, the health of the processor, the longevity of the injection molding machine as well as the material and product properties can be protected.

  18. Tangential acceleration feedback control of friction induced vibration

    NASA Astrophysics Data System (ADS)

    Nath, Jyayasi; Chatterjee, S.

    2016-09-01

    Tangential control action is studied on a phenomenological mass-on-belt model exhibiting friction-induced self-excited vibration attributed to the low-velocity drooping characteristics of friction which is also known as Stribeck effect. The friction phenomenon is modelled by the exponential model. Linear stability analysis is carried out near the equilibrium point and local stability boundary is delineated in the plane of control parameters. The system is observed to undergo a Hopf bifurcation as the eigenvalues determined from the linear stability analysis are found to cross the imaginary axis transversally from RHS s-plane to LHS s-plane or vice-versa as one varies the control parameters, namely non-dimensional belt velocity and the control gain. A nonlinear stability analysis by the method of Averaging reveals the subcritical nature of the Hopf bifurcation. Thus, a global stability boundary is constructed so that any choice of control parameters from the globally stable region leads to a stable equilibrium. Numerical simulations in a MATLAB SIMULINK model and bifurcation diagrams obtained in AUTO validate these analytically obtained results. Pole crossover design is implemented to optimize the filter parameters with an independent choice of belt velocity and control gain. The efficacy of this optimization (based on numerical results) in the delicate low velocity region is also enclosed.

  19. Instrumentation for diagnostics and control of laser-accelerated proton (ion) beams.

    PubMed

    Bolton, P R; Borghesi, M; Brenner, C; Carroll, D C; De Martinis, C; Fiorini, Francesca; Flacco, A; Floquet, V; Fuchs, J; Gallegos, P; Giove, D; Green, J S; Green, S; Jones, B; Kirby, D; McKenna, P; Neely, D; Nuesslin, F; Prasad, R; Reinhardt, S; Roth, M; Schramm, U; Scott, G G; Ter-Avetisyan, S; Tolley, M; Turchetti, G; Wilkens, J J

    2014-05-01

    Suitable instrumentation for laser-accelerated proton (ion) beams is critical for development of integrated, laser-driven ion accelerator systems. Instrumentation aimed at beam diagnostics and control must be applied to the driving laser pulse, the laser-plasma that forms at the target and the emergent proton (ion) bunch in a correlated way to develop these novel accelerators. This report is a brief overview of established diagnostic techniques and new developments based on material presented at the first workshop on 'Instrumentation for Diagnostics and Control of Laser-accelerated Proton (Ion) Beams' in Abingdon, UK. It includes radiochromic film (RCF), image plates (IP), micro-channel plates (MCP), Thomson spectrometers, prompt inline scintillators, time and space-resolved interferometry (TASRI) and nuclear activation schemes. Repetition-rated instrumentation requirements for target metrology are also addressed. PMID:24100298

  20. Active suppression of vortex-driven combustion instability using controlled liquid-fuel injection

    NASA Astrophysics Data System (ADS)

    Pang, Bin

    Combustion instabilities remain one of the most challenging problems encountered in developing propulsion and power systems. Large amplitude pressure oscillations, driven by unsteady heat release, can produce numerous detrimental effects. Most previous active control studies utilized gaseous fuels to suppress combustion instabilities. However, using liquid fuel to suppress combustion instabilities is more realistic for propulsion applications. Active instability suppression in vortex-driven combustors using a direct liquid fuel injection strategy was theoretically established and experimentally demonstrated in this dissertation work. Droplet size measurements revealed that with pulsed fuel injection management, fuel droplet size could be modulated periodically. Consequently, desired heat release fluctuation could be created. If this oscillatory heat release is coupled with the natural pressure oscillation in an out of phase manner, combustion instabilities can be suppressed. To identify proper locations of supplying additional liquid fuel for the purpose of achieving control, the natural heat release pattern in a vortex-driven combustor was characterized in this study. It was found that at high Damkohler number oscillatory heat release pattern closely followed the evolving vortex front. However, when Damkohler number became close to unity, heat release fluctuation wave no longer coincided with the coherent structures. A heat release deficit area was found near the dump plane when combustor was operated in lean premixed conditions. Active combustion instability suppression experiments were performed in a dump combustor using a controlled liquid fuel injection strategy. High-speed Schlieren results illustrated that vortex shedding plays an important role in maintaining self-sustained combustion instabilities. Complete combustion instability control requires total suppression of these large-scale coherent structures. The sound pressure level at the excited dominant

  1. Non-linear stochastic optimal control of acceleration parametrically excited systems

    NASA Astrophysics Data System (ADS)

    Wang, Yong; Jin, Xiaoling; Huang, Zhilong

    2016-02-01

    Acceleration parametrical excitations have not been taken into account due to the lack of physical significance in macroscopic structures. The explosive development of microtechnology and nanotechnology, however, motivates the investigation of the acceleration parametrically excited systems. The adsorption and desorption effects dramatically change the mass of nano-sized structures, which significantly reduces the precision of nanoscale sensors or can be reasonably utilised to detect molecular mass. This manuscript proposes a non-linear stochastic optimal control strategy for stochastic systems with acceleration parametric excitation based on stochastic averaging of energy envelope and stochastic dynamic programming principle. System acceleration is approximately expressed as a function of system displacement in a short time range under the conditions of light damping and weak excitations, and the acceleration parametrically excited system is shown to be equivalent to a constructed system with an additional displacement parametric excitation term. Then, the controlled system is converted into a partially averaged Itô equation with respect to the total system energy through stochastic averaging of energy envelope, and the optimal control strategy for the averaged system is derived from solving the associated dynamic programming equation. Numerical results for a controlled Duffing oscillator indicate the efficacy of the proposed control strategy.

  2. Randomised controlled trial of local corticosteroid injections for de Quervain's tenosynovitis in general practice

    PubMed Central

    Peters-Veluthamaningal, Cyriac; Winters, Jan C; Groenier, Klaas H; Meyboom-deJong, Betty

    2009-01-01

    Background De Quervain's tenosynovitis is a stenosing tenosynovitis of the first dorsal compartment of the wrist and leads to wrist pain and to impaired function of the wrist and hand. It can be treated by splinting, local corticosteroid injection and operation. In this study effectiveness of local corticosteroid injections for de Quervain's tenosynovitis provided by general practitioners was assessed. Methods Participants with de Quervain's tenosynovitis were recruited by general practitioners. Short-term outcomes (one week after injections) were assessed in a randomised, placebo-controlled trial. Long-term effectiveness was evaluated in an open prospective cohort-study of steroid responders during a follow-up period of 12 months. Participants were randomised to one or two local injections of 1 ml of triamcinolonacetonide (TCA) or 1 ml of NaCl 0.9% (placebo). Non-responders to NaCl were treated with additional TCA injections. Main outcomes were immediate treatment response, severity of pain, improvement as perceived by participant and functional disability using sub items hand and finger function of the Dutch Arthritis Impact Measurement Scale (Dutch AIMS-2-HFF). Results 11 general practitioners included 21 wrists in 21 patients. The TCA-group had better results for short-term outcomes treatment response (78% vs. 25%; p = 0.015), perceived improvement (78% vs. 33%; p = 0.047) and severity of pain (4.27 vs. 1.33; p = 0.031) but not for the Dutch-AIMS-HFF (2.71 vs. 1.92; p = 0.112). Absolute risk reduction for the main outcome short-term treatment response was 0.55 (95% CI: 0.34, 0.76) with a number needed to treat of 2 (95% CI: 1, 3). In the cohort of steroid responders (n = 12) the beneficial effects of steroid injections were sustained during the follow-up of 12 months regarding severity of pain (p = 0.67) and scores of Dutch AIMS-2-HFF (p = 0.36), but not for patient perceived improvement (p = 0.02). No adverse events were observed during the 12 months of follow

  3. Optimizing a mobile robot control system using GPU acceleration

    NASA Astrophysics Data System (ADS)

    Tuck, Nat; McGuinness, Michael; Martin, Fred

    2012-01-01

    This paper describes our attempt to optimize a robot control program for the Intelligent Ground Vehicle Competition (IGVC) by running computationally intensive portions of the system on a commodity graphics processing unit (GPU). The IGVC Autonomous Challenge requires a control program that performs a number of different computationally intensive tasks ranging from computer vision to path planning. For the 2011 competition our Robot Operating System (ROS) based control system would not run comfortably on the multicore CPU on our custom robot platform. The process of profiling the ROS control program and selecting appropriate modules for porting to run on a GPU is described. A GPU-targeting compiler, Bacon, is used to speed up development and help optimize the ported modules. The impact of the ported modules on overall performance is discussed. We conclude that GPU optimization can free a significant amount of CPU resources with minimal effort for expensive user-written code, but that replacing heavily-optimized library functions is more difficult, and a much less efficient use of time.

  4. Modification of the logic and control system for the 80-ounce injection molding machine

    SciTech Connect

    Domer, G.A.

    1990-01-01

    The modification of the hydraulic logic and control system for the 80-ounce injection molding machine in the Molding and Machining, Plastics, department was required to allow production of near net size thick-walled parts and machining stock from high-shrinkage materials while retaining the original logic for standard product. The control system that was developed allows the new capability of open clamp injection. This capability will replace the present method of purchasing machining stock from an outside source. The control system was implemented with a Giddings Lewis Programmable Industrial Computer 409 (G L PiC 409). Hydraulic modifications included adding Vickers servo valves, an Inductosyn position transducer, and MOOG pressure transducers to perform force and position control. The control system provides two capabilities, NORMAL and SERVO. The NORMAL mode is defined as operating the machine according to original design specifications. The SERVO mode is defined as operating the machine according to a recipe in open loop position control then in closed loop force control. The G L PiC 409 controls the tasks of both modes. A selector switch determines the mode of operation (NORMAL or SERVO). The NORMAL mode uses the original hydraulic circuits, and the SERVO mode diverts fluid into the modified hydraulic circuits. 11 figs.

  5. Control of the upper body accelerations in young and elderly women during level walking

    PubMed Central

    Mazzà, Claudia; Iosa, Marco; Pecoraro, Fabrizio; Cappozzo, Aurelio

    2008-01-01

    Background The control of the head movements during walking allows for the stabilisation of the optic flow, for a more effective processing of the vestibular system signals, and for the consequent control of equilibrium. In young individuals, the oscillations of the upper body during level walking are characterised by an attenuation of the linear acceleration going from pelvis to head level. In elderly subjects the ability to implement this motor strategy is reduced. The aim of this paper is to go deeper into the mechanisms through which the head accelerations are controlled during level walking, in both young and elderly women specifically. Methods A stereophotogrammetric system was used to reconstruct the displacement of markers located at head, shoulder, and pelvis level while 16 young (age: 24 ± 4 years) and 20 older (age: 72 ± 4 years) female volunteers walked at comfortable and fast speed along a linear pathway. The harmonic coefficients of the displacements in the medio-lateral (ML), antero-posterior (AP), and vertical (V) directions were calculated via discrete Fourier transform, and relevant accelerations were computed by analytical double differentiation. The root mean square of the accelerations were used to define three coefficients for quantifying the attenuations of the accelerations from pelvis to head, from pelvis to shoulder, and from shoulder to head. Results The coefficients of attenuation were shown to be independent from the walking speed, and hence suitable for group and subject comparison. The acceleration in the AP direction was attenuated by the two groups both from pelvis to shoulder and from shoulder to head. The reduction of the shoulder to head acceleration, however, was less effective in older women, suggesting that the ability to exploit the cervical hinge to attenuate the AP acceleration is challenged in this population. Young women managed to exploit a pelvis to shoulder attenuation strategy also in the ML direction, whereas in

  6. Engineered and Administrative Safety Systems for the Control of Prompt Radiation Hazards at Accelerator Facilities

    SciTech Connect

    Liu, James C.; Vylet, Vashek; Walker, Lawrence S.; /SLAC

    2007-12-17

    The ANSI N43.1 Standard, currently in revision (ANSI 2007), sets forth the requirements for accelerator facilities to provide adequate protection for the workers, the public and the environment from the hazards of ionizing radiation produced during and from accelerator operations. The Standard also recommends good practices that, when followed, provide a level of radiation protection consistent with those established for the accelerator communities. The N43.1 Standard is suitable for all accelerator facilities (using electron, positron, proton, or ion particle beams) capable of producing radiation, subject to federal or state regulations. The requirements (see word 'shall') and recommended practices (see word 'should') are prescribed in a graded approach that are commensurate with the complexity and hazard levels of the accelerator facility. Chapters 4, 5 and 6 of the N43.1 Standard address specially the Radiation Safety System (RSS), both engineered and administrative systems, to mitigate and control the prompt radiation hazards from accelerator operations. The RSS includes the Access Control System (ACS) and Radiation Control System (RCS). The main requirements and recommendations of the N43.1 Standard regarding the management, technical and operational aspects of the RSS are described and condensed in this report. Clearly some aspects of the RSS policies and practices at different facilities may differ in order to meet the practical needs for field implementation. A previous report (Liu et al. 2001a), which reviews and summarizes the RSS at five North American high-energy accelerator facilities, as well as the RSS references for the 5 labs (Drozdoff 2001; Gallegos 1996; Ipe and Liu 1992; Liu 1999; Liu 2001b; Rokni 1996; TJNAF 1994; Yotam et al. 1991), can be consulted for the actual RSS implementation at various laboratories. A comprehensive report describing the RSS at the Stanford Linear Accelerator Center (SLAC 2006) can also serve as a reference.

  7. FPGA-accelerated adaptive optics wavefront control part II

    NASA Astrophysics Data System (ADS)

    Mauch, S.; Barth, A.; Reger, J.; Reinlein, C.; Appelfelder, M.; Beckert, E.

    2015-03-01

    We present progressive work that is based on our recently developed rapid control prototyping system (RCP), designed for the implementation of high-performance adaptive optical control algorithms using a continuous de-formable mirror (DM). The RCP system, presented in 2014, is resorting to a Xilinx Kintex-7 Field Programmable Gate Array (FPGA), placed on a self-developed PCIe card, and installed on a high-performance computer that runs a hard real-time Linux operating system. For this purpose, algorithms for the efficient evaluation of data from a Shack-Hartmann wavefront sensor (SHWFS) on an FPGA have been developed. The corresponding analog input and output cards are designed for exploiting the maximum possible performance while not being constrained to a specific DM and control algorithm due to the RCP approach. In this second part of our contribution, we focus on recent results that we achieved with this novel experimental setup. By presenting results which are far superior to the former ones, we further justify the deployment of the RCP system and its required time and resources. We conducted various experiments for revealing the effective performance, i.e. the maximum manageable complexity in the controller design that may be achieved in real-time without performance losses. A detailed analysis of the hidden latencies is carried out, showing that these latencies have been drastically reduced. In addition, a series of concepts relating the evaluation of the wavefront as well as designing and synthesizing a wavefront are thoroughly investigated with the goal to overcome some of the prevalent limitations. Furthermore, principal results regarding the closed-loop performance of the low-speed dynamics of the integrated heater in a DM concept are illustrated in detail; to be combined with the piezo-electric high-speed actuators in the next step

  8. Modern approaches to accelerator simulation and on-line control

    SciTech Connect

    Lee, M.; Clearwater, S.; Theil, E.; Paxson, V.

    1987-02-01

    COMFORT-PLUS consists of three parts: (1) COMFORT (Control Of Machine Function, ORbits, and Trajectories), which computes the machine lattice functions and transport matrices along a beamline; (2) PLUS (Prediction from Lattice Using Simulation) which finds or compensates for errors in the beam parameters or machine elements; and (3) a highly graphical interface to PLUS. The COMFORT-PLUS package has been developed on a SUN-3 workstation. The structure and use of COMFORT-PLUS are described, and an example of the use of the package is presented. (LEW)

  9. Artificial intelligence research in particle accelerator control systems for beam line tuning

    SciTech Connect

    Pieck, Martin

    2008-01-01

    Tuning particle accelerators is time consuming and expensive, with a number of inherently non-linear interactions between system components. Conventional control methods have not been successful in this domain and the result is constant and expensive monitoring of the systems by human operators. This is particularly true for the start-up and conditioning phase after a maintenance period or an unexpected fault. In turn, this often requires a step-by-step restart of the accelerator. Surprisingly few attempts have been made to apply intelligent accelerator control techniques to help with beam tuning, fault detection, and fault recovery problems. The reason for that might be that accelerator facilities are rare and difficult to understand systems that require detailed expert knowledge about the underlying physics as well as months if not years of experience to understand the relationship between individual components, particularly if they are geographically disjoint. This paper will give an overview about the research effort in the accelerator community that has been dedicated to the use of artificial intelligence methods for accelerator beam line tuning.

  10. Vasectomy with rivanol injection and fertility control by vital staining with eosin.

    PubMed

    Lauritsen, N P; Kløve-Mogensen, M; Glavind, K

    1987-01-01

    A material is presented of 66 males who were treated with Rivanol injection during vasectomy in order to obtain immediate sterility. The fertility control was established using vital eosin staining on seminal fluid at home. One case of recanalization occurred. All patients had infertile spermatozoa or aspermia 10 days after surgery. Increased frequency of complications was not observed. Vital staining with eosin is found to be practical and easily used. PMID:2448262

  11. Nuclear Safety Functions of ITER Gas Injection System Instrumentation and Control and the Concept Design

    NASA Astrophysics Data System (ADS)

    Yang, Yu; Maruyama, S.; Fossen, A.; Villers, F.; Kiss, G.; Zhang, Bo; Li, Bo; Jiang, Tao; Huang, Xiangmei

    2016-08-01

    The ITER Gas Injection System (GIS) plays an important role on fueling, wall conditioning and distribution for plasma operation. Besides that, to support the safety function of ITER, GIS needs to implement three nuclear safety Instrumentation and Control (I&C) functions. In this paper, these three functions are introduced with the emphasis on their latest safety classifications. The nuclear I&C design concept is briefly discussed at the end.

  12. Status of the Advanced Photon Source and its accelerator control system

    SciTech Connect

    McDowell, W.; Knott, M.; Kraimer, K.M.

    1993-11-01

    This paper presents the current status of the Advanced Photon Source (APS), its control system and the Experimental Physics and Industrial Control System (EPICS) tools being used to implement this control system. The status of the physical plant and each of the accelerators as well as detailed descriptions of the software tools used to build the accelerator control system are presented. The control system uses high-performance graphic workstations and the X-windows graphical user interface (GUI) at the operator interface level. It connects to VME/VXI-based microprocessors at the field level using TCP/IP protocols over high-performance networks. This strategy assures the flexibility and expansibility of the control system. A defined interface between the system components will allow the system to evolve with the direct addition of future, improved equipment and new capabilities.

  13. Investigating the feasibility of temperature-controlled accelerated drug release testing for an intravaginal ring.

    PubMed

    Externbrink, Anna; Clark, Meredith R; Friend, David R; Klein, Sandra

    2013-11-01

    The objective of the present study was to investigate if temperature can be utilized to accelerate drug release from Nuvaring®, a reservoir type intravaginal ring based on polyethylene vinyl acetate copolymer that releases a constant dose of contraceptive steroids over a duration of 3 weeks. The reciprocating holder apparatus (USP 7) was utilized to determine real-time and accelerated etonogestrel release from ring segments. It was demonstrated that drug release increased with increasing temperature which can be attributed to enhanced drug diffusion. An Arrhenius relationship of the zero-order release constants was established, indicating that temperature is a valid parameter to accelerate drug release from this dosage form and that the release mechanism is maintained under these accelerated test conditions. Accelerated release tests are particularly useful for routine quality control to assist during batch release of extended release formulations that typically release the active over several weeks, months or even years, since they can increase the product shelf life. The accelerated method should therefore be able to discriminate between formulations with different release characteristics that can result from normal manufacturing variance. In the case of Nuvaring®, it is well known that the process parameters during the extrusion process strongly influence the polymeric structure. These changes in the polymeric structure can affect the permeability which, in turn, is reflected in the release properties. Results from this study indicate that changes in the polymeric structure can lead to a different temperature dependence of the release rate, and as a consequence, the accelerated method can become less sensitive to detect changes in the release properties. When the accelerated method is utilized during batch release, it is therefore important to take this possible restriction into account and to evaluate the accelerated method with samples from non

  14. Generalized control and data access at the LANSCE Accelerator Complex -- Gateway, migrators, and other servers

    SciTech Connect

    Schaller, S.C.; Oothoudt, M.A.

    1995-12-01

    All large accelerator control systems eventually outlast the technologies with which they were built. This has happened several times during the lifetime of the accelerators at Los Alamos in the LAMPF/PSR beam delivery complex. Most recently, the EPICS control system has been integrated with the existing LAMPF and PSR control systems. In this paper, the authors discuss the provisions that were made to provide uniform, and nearly transparent sharing of data among the three control systems. The data sharing mechanisms have now been in use during a very successful beam production period. They comment on the successes and failures of the project and indicate the control system properties that make such sharing possible.

  15. Addition of Lidocaine Injection Immediately before Physiotherapy for Frozen Shoulder: A Randomized Controlled Trial

    PubMed Central

    Hsu, Wei-Chun; Wang, Tao-Liang; Lin, Yi-Jia; Hsieh, Lin-Fen; Tsai, Chun-Mei; Huang, Kuang-Hui

    2015-01-01

    The intraarticular injection of lidocaine immediately before a physiotherapy session may relieve pain during the stretching and mobilization of the affected joint in patients with a frozen shoulder, thus enhancing the treatment effect. To compare the effects of intraarticular injection of lidocaine plus physiotherapy to that of physiotherapy alone in the treatment of a frozen shoulder, a prospective randomized controlled trial was conducted in the rehabilitation department of a private teaching hospital. Patients with a frozen shoulder were randomized into the physiotherapy group or the lidocaine injection plus physiotherapy (INJPT) group. The subjects in the INJPT group underwent injection of 3 ml of 1% lidocaine into the affected shoulder 10 to 20 minutes before each physiotherapy session. In each group, the treatment lasted 3 months. The primary outcome measures were the active and passive range of motion of the affected shoulder. The secondary outcome measures were the results of the Shoulder Disability Questionnaire, the Shoulder Pain and Disability Index, and the 36-item Short-Form Health Survey (SF-36). The outcome measures were evaluated before treatment and 1, 2, 3, 4, and 6 months after the start of treatment. The group comparisons showed significantly greater improvement in the INJPT group, mainly in active and passive shoulder range of motion in flexion and external rotation and improvements in pain and disability (P < 0.05); however, no significant group difference was seen in the SF-36 results. The intraarticular injection of lidocaine immediately before a physiotherapy session might be superior to physiotherapy alone in the treatment of a frozen shoulder. Trial Registration ClinicalTrials.gov NCT01817348 PMID:25714415

  16. Characterization of a high-pressure diesel fuel injection system as a control technology option to improve engine performance and reduce exhaust emissions

    NASA Technical Reports Server (NTRS)

    Mcfadden, J. J.; Dezelick, R. A.; Barrows, R. R.

    1983-01-01

    Test results from a high pressure electronically controlled fuel injection system are compared with a commercial mechanical injection system on a single cylinder, diesel test engine using an inlet boost pressure of 2.6:1. The electronic fuel injection system achieved high pressure by means of a fluid intensifier with peak injection pressures of 47 to 69 MPa. Reduced exhaust emissions were demonstrated with an increasing rate of injection followed by a fast cutoff of injection. The reduction in emissions is more responsive to the rate of injection and injection timing than to high peak injection pressure.

  17. Electron Injection to Control Self-Assembly and Disassembly of Phenylacetylene on Gold

    NASA Astrophysics Data System (ADS)

    Baddorf, Arthur P.; Li, Qing; Han, Chengbo; Bernholc, J.; Terrones, Humberto; Sumpter, Bobby; Fuentes-Cabrera, Miguel; Yi, Jieyu; Gai, Zheng; Maksymovych, Peter; Pan, Minghu

    2013-03-01

    The power of two-dimensional organic molecular systems for applications including electronics, functionalization and nanolithography is enabled by our ability to produce structures through self-assembly on a surface. Unfortunately, relying on thermal fluctuations to drive the surface attachment reactions has limited self-assembled molecules (SAMs) to little beyond alkanethiols on gold. We demonstrate a seminal example of non-thermal control over molecular self-assembly, where hot-electron injection rather than thermal fluctuations transform a disordered layer of weakly bonded hydrocarbon molecules into an ordered, dense monolayer. The process is reversible, in that injection of holes reverts to a disordered state. Since electron and hole injection is accomplished with a STM, unprecedented local control over ordered and disordered domains is achieved. STM imaging and correlated density functional calculations reveal that ordered domains consist of molecules vertically aligned and more strongly attached to the gold substrate through the acetylene tail, while disordered domains contain weakly bound molecules lying flat. Research was conducted at the CNMS, sponsored by the Division of Scientific User Facilities, U.S. Department of Energy.

  18. Controlled Human Malaria Infection of Tanzanians by Intradermal Injection of Aseptic, Purified, Cryopreserved Plasmodium falciparum Sporozoites

    PubMed Central

    Shekalaghe, Seif; Rutaihwa, Mastidia; Billingsley, Peter F.; Chemba, Mwajuma; Daubenberger, Claudia A.; James, Eric R.; Mpina, Maximillian; Ali Juma, Omar; Schindler, Tobias; Huber, Eric; Gunasekera, Anusha; Manoj, Anita; Simon, Beatus; Saverino, Elizabeth; Church, L. W. Preston; Hermsen, Cornelus C.; Sauerwein, Robert W.; Plowe, Christopher; Venkatesan, Meera; Sasi, Philip; Lweno, Omar; Mutani, Paul; Hamad, Ali; Mohammed, Ali; Urassa, Alwisa; Mzee, Tutu; Padilla, Debbie; Ruben, Adam; Lee Sim, B. Kim; Tanner, Marcel; Abdulla, Salim; Hoffman, Stephen L.

    2014-01-01

    Controlled human malaria infection (CHMI) by mosquito bite has been used to assess anti-malaria interventions in > 1,500 volunteers since development of methods for infecting mosquitoes by feeding on Plasmodium falciparum (Pf) gametocyte cultures. Such CHMIs have never been used in Africa. Aseptic, purified, cryopreserved Pf sporozoites, PfSPZ Challenge, were used to infect Dutch volunteers by intradermal injection. We conducted a double-blind, placebo-controlled trial to assess safety and infectivity of PfSPZ Challenge in adult male Tanzanians. Volunteers were injected intradermally with 10,000 (N = 12) or 25,000 (N = 12) PfSPZ or normal saline (N = 6). PfSPZ Challenge was well tolerated and safe. Eleven of 12 and 10 of 11 subjects, who received 10,000 and 25,000 PfSPZ respectively, developed parasitemia. In 10,000 versus 25,000 PfSPZ groups geometric mean days from injection to Pf positivity by thick blood film was 15.4 versus 13.5 (P = 0.023). Alpha-thalassemia heterozygosity had no apparent effect on infectivity. PfSPZ Challenge was safe, well tolerated, and infectious. PMID:25070995

  19. Determination of dry carbon-based sorbent injection for mercury control in utility ESP and baghouses

    SciTech Connect

    Broderick, T.; Haythornthwaite, S.; Bell, W.; Selegue, T.; Perry, M.

    1998-12-31

    Domestic coal-fired power plants emit approximately 40 to 80 metric tons of mercury to the atmosphere annually. The mercury concentration in utility flue gas is in the dilute range of 0.1 to 1 parts per billion. The EPA is assessing whether such low concentrations of mercury emissions from coal-fired utilities pose any significant health risk and whether mercury regulations would be necessary or appropriate. In anticipation of possible mercury control regulations, ADA Technologies (ADA) and TDA Research, Inc (TDA) were funded by the Department of Energy (DOE) to evaluate carbon-based sorbents for mercury control at utility coal-fired power plants. Past investigations of the use of dry carbon-based sorbent injection for mercury control on pilot-scale utility flue gas applications have shown that these sorbents are capable of removing gas-phase mercury. ADA Technologies field-tested the mercury removal capability of several carbon-based sorbents manufactured by TDA. The test facility was a DOE-owned test facility built and operated by ADA at the Public Service Company of Colorado`s Comanche Station in Pueblo, Colorado. The pilot-scale test fixture is a 600-acfm particulate control module that can be configured as an electrostatic precipitator, a pulse-jet baghouse, or a reverse-gas baghouse. It extracts a slipstream of flue gas from a coal-fired utility boiler. Sorbent is injected into the flue gas slipstream upstream of the particulate control module and is removed by the module. ADA evaluated the mercury capture efficiency of the sorbents over a range of flue gas temperatures and injection rates. In addition, the effect of flyash on mercury capture was also investigated. The test facility is configured to take flue gas from either upstream or downstream of Comanche Station`s full-scale reverse-gas baghouse, allowing tests to be conducted with normal-ash or low-ash flue gas.

  20. Geological controls on the performance of CO2 injection and storage sites

    NASA Astrophysics Data System (ADS)

    Ringrose, P. S.; Nazarian, B.; Gemmer, L.; Cavanagh, A.

    2011-12-01

    Using experience gained from several pioneering industrial-scale CO2 storage projects we identify the key factors controlling injection performance, both for the injection period (c. 10 years) and for the longer term (>10 years). The Sleipner, In Salah and Snøhvit storage sites, which together have succeeded in disposing of over 16 Mt of CO2, present highly variable reservoirs, covering a range of reservoir depth, permeability and geological architecture. Reservoir modelling studies show how CO2 plume development has been controlled by geology, geo-mechanics and fluid phase behaviour. Three general themes about CO2 in the subsurface emerge from these cases studies: a) Geology: Variations in geological architecture result in highly non-uniform plume development. Short-term and near-well injection performance is viscous dominated, while longer-term and far-field performance becomes gravity/capillary dominated. The case studies illustrate how thin-shale layers, top-reservoir topography, faults and fractures control actual CO2 plume development. Understanding how these controls affect field performance is best achieved by careful tuning of reservoir models to observations from reservoir monitoring. b) Rock mechanics: Geo-mechanical properties affect storage capacity, limit well injectivity and determine pressure development within the reservoir. Simple linear elastic models are generally insufficient, whereas by using detailed mechanical models we have been able to fine-tune the reservoir and overburden mechanical models to learn how the rock system responds to fluid pressure. c) Phase behaviour: While pure CO2 phase behaviour is well understood, the behaviour of gas mixtures, within the inherently uncertain ranges of in situ reservoir pressure and temperature, presents a significant challenge, leading to large uncertainties in gas density, viscosity, and solubility. Detailed models of near-wellbore multi-phase flow show how injectivity and plume growth around the

  1. Correlation between Rotator Cuff Tears and Repeated Subacromial Steroid Injections: A Case-Controlled Study

    PubMed Central

    Bhatia, M; Singh, B; Nicolaou, N; Ravikumar, KJ

    2009-01-01

    INTRODUCTION Concern exists regarding potential damage to the rotator cuff from repeated corticosteroid injections into the subacromial space. PATIENTS AND METHODS In this retrospective, case-controlled study, 230 consecutive patients presenting to three orthopaedic units with subacromial impingement and investigated as an end-point with magnetic resonance imaging (MRI) of the shoulder were divided into groups having received less than three or three or more subacromial injections of corticosteroids. RESULTS With no significant difference in age and sex distribution, analysis by MRI showed no significant difference between the two groups in the incidence of rotator cuff tear (P < 1.0). CONCLUSIONS This suggests that corticosteroid use in patients with subacromial impingement should not be considered a causative factor in rotator cuff tears. PMID:19409148

  2. Modeling and control of plasma rotation for NSTX using neoclassical toroidal viscosity and neutral beam injection

    NASA Astrophysics Data System (ADS)

    Goumiri, I. R.; Rowley, C. W.; Sabbagh, S. A.; Gates, D. A.; Gerhardt, S. P.; Boyer, M. D.; Andre, R.; Kolemen, E.; Taira, K.

    2016-03-01

    A model-based feedback system is presented to control plasma rotation in a magnetically confined toroidal fusion device, to maintain plasma stability for long-pulse operation. This research uses experimental measurements from the National Spherical Torus Experiment (NSTX) and is aimed at controlling plasma rotation using two different types of actuation: momentum from injected neutral beams and neoclassical toroidal viscosity generated by three-dimensional applied magnetic fields. Based on the data-driven model obtained, a feedback controller is designed, and predictive simulations using the TRANSP plasma transport code show that the controller is able to attain desired plasma rotation profiles given practical constraints on the actuators and the available measurements of rotation.

  3. Data acquisition, control, and analysis for the Argonne Advanced Accelerator Test Facility (AATF)

    SciTech Connect

    Schoessow, P.

    1989-01-01

    The AATF has been used to study wakefield acceleration and focusing in plasmas and rf structures. A PC-based system is described which incorporates the functions of beamline control and acquisition, storage, and preliminary analysis of video images from luminescent screen beam diagnostics. General features of the offline analysis of wakefield data are also discussed. 4 refs., 3 figs.

  4. 49 CFR 571.124 - Standard No. 124; Accelerator control systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR VEHICLE SAFETY STANDARDS Federal Motor Vehicle Safety Standards § 571.124 Standard No. 124; Accelerator control systems. S1. Scope. This standard establishes requirements for the return of a vehicle's throttle to the idle position...

  5. 49 CFR 571.124 - Standard No. 124; Accelerator control systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR VEHICLE SAFETY STANDARDS Federal Motor Vehicle Safety Standards § 571.124 Standard No. 124; Accelerator control systems. S1. Scope. This standard establishes requirements for the return of a vehicle's throttle to the idle position...

  6. 49 CFR 571.124 - Standard No. 124; Accelerator control systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 6 2014-10-01 2014-10-01 false Standard No. 124; Accelerator control systems. 571.124 Section 571.124 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR VEHICLE SAFETY STANDARDS Federal Motor Vehicle Safety Standards...

  7. 49 CFR 571.124 - Standard No. 124; Accelerator control systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR VEHICLE SAFETY STANDARDS Federal Motor Vehicle Safety Standards § 571.124 Standard No. 124; Accelerator control systems. S1. Scope. This standard establishes requirements for the return of a vehicle's throttle to the idle position...

  8. Plasma gradient controlled injection and postacceleration of high quality electron bunches

    SciTech Connect

    Geddes, C. G. R.; Cormier-Michel, E.; Nakamura, K.; Schroeder, C. B.; Toth, Cs.; Esarey, E.; Plateau, G. R.; Bruhwiler, D. L.; Cary, J. R.; Leemans, W. P.

    2009-01-22

    Plasma density gradient control of wake phase velocity and trapping threshold in a laser wakefield accelerator produced electron bunches with absolute longitudinal and transverse momentum spreads more than ten times lower than in previous experiments (0.17 and 0.02 MeV/c FWHM, respectively) and with central momenta of 0.76{+-}0.02 MeV/c, stable over a week of operation. Simulations validated against diagnostics show that use of such bunches as a wakefield accelerator injector can produce stable beams with 0.2 MeV/c-class momentum spread at high energies. Preservation of bunch momentum spread requires high simulation momentum accuracy, and related self-trapped simulations showed that high order particle weight effectively suppresses simulation momentum errors allowing design of low emittance stages.

  9. Sorbent Injection for Small ESP Mercury Control in Low Sulfur Eastern Bituminous Coal Flue Gas

    SciTech Connect

    Carl Richardson; Katherine Dombrowski; Douglas Orr

    2006-12-31

    This project Final Report is submitted to the U.S. Department of Energy (DOE) as part of Cooperative Agreement DE-FC26-03NT41987, 'Sorbent Injection for Small ESP Mercury Control in Low Sulfur Eastern Bituminous Coal Flue Gas.' Sorbent injection technology is targeted as the primary mercury control process on plants burning low/medium sulfur bituminous coals equipped with ESP and ESP/FGD systems. About 70% of the ESPs used in the utility industry have SCAs less than 300 ft2/1000 acfm. Prior to this test program, previous sorbent injection tests had focused on large-SCA ESPs. This DOE-NETL program was designed to generate data to evaluate the performance and economic feasibility of sorbent injection for mercury control at power plants that fire bituminous coal and are configured with small-sized electrostatic precipitators and/or an ESP-flue gas desulfurization (FGD) configuration. EPRI and Southern Company were co-funders for the test program. Southern Company and Reliant Energy provided host sites for testing and technical input to the project. URS Group was the prime contractor to NETL. ADA-ES and Apogee Scientific Inc. were sub-contractors to URS and was responsible for all aspects of the sorbent injection systems design, installation and operation at the different host sites. Full-scale sorbent injection for mercury control was evaluated at three sites: Georgia Power's Plant Yates Units 1 and 2 [Georgia Power is a subsidiary of the Southern Company] and Reliant Energy's Shawville Unit 3. Georgia Power's Plant Yates Unit 1 has an existing small-SCA cold-side ESP followed by a Chiyoda CT-121 wet scrubber. Yates Unit 2 is also equipped with a small-SCA ESP and a dual flue gas conditioning system. Unit 2 has no SO2 control system. Shawville Unit 3 is equipped with two small-SCA cold-side ESPs operated in series. All ESP systems tested in this program had SCAs less than 250 ft2/1000 acfm. Short-term parametric tests were conducted on Yates Units 1 and 2 to evaluate

  10. Pilot-scale carbon injection for mercury control at Comanche Station

    SciTech Connect

    Haythornthwaite, S.M.; Smith, J.; Anderson, G.; Hunt, T.; Fox, M.; Chang, R.; Brown, T.

    1999-07-01

    The Department of Energy is sponsoring an investigation of the applicability of using activated carbon sorbents for control of mercury emissions from coal-fired power plants. There is a significant level of federal regulatory interest regarding the need and feasibility of controlling these emissions. This interest arises from the status of coal-fired power plants as responsible for approximately 33% of the estimated anthropogenic mercury emissions in the U.S. EPA decided in April 1998 that although current technologies and emission data were not sufficiently developed to require implementation today, the results of further study and testing would determine regulatory direction within three to five years. DOE, Public Service Company of Colorado (PSCo), and EPRI are funding pilot and field tests to evaluate the feasibility of carbon injection as a potential mercury control technology. ADA Technologies performs the fabrication, pilot operation, and reporting. The work described in this paper is a summary of test results on a 600- actual cubic feet per minute (acfm) pilot-scale particulate collector, configurable as an ESP or baghouse. This pilot is installed at PSCo's Comanche Station, and has been operating since mid-1996. Testing to determine the efficacy of carbon injection as a mercury control technology on this pilot, has provided mixed results and many questions remain concerning this technology. One of the challenges encountered in this project has been in mercury measurement and test repeatability. Improvements have been made in sampling methodology which have resulted in improved repeatability among replicate tests. Mercury removal rates as a function of flue gas temperature and carbon injection rate have been quantified and preliminary results are presented in this paper. The transferability of results to full-scale or to other coal-fired power plants is still being evaluated under this program.

  11. Self-injection and acceleration of electrons during ionization of gas atoms by a short laser pulse

    SciTech Connect

    Singh, K.P.

    2006-04-15

    Using a relativistic three-dimensional single-particle code, acceleration of electrons created during the ionization of nitrogen and oxygen gas atoms by a laser pulse has been studied. Barrier suppression ionization model has been used to calculate ionization time of the bound electrons. The energy gained by the electrons peaks for an optimum value of laser spot size. The electrons created near the tail do not gain sufficient energy for a long duration laser pulse. The electrons created at the tail of pulse escape before fully interacting with the trailing part of the pulse for a short duration laser pulse, which causes electrons to retain sufficient energy. If a suitable frequency chirp is introduced then energy of the electrons created at the tail of the pulse further increases.

  12. Architecture, implementation, and testing of a multiple-shell gas injection system for high current implosions on the Z accelerator.

    PubMed

    Krishnan, Mahadevan; Elliott, Kristi Wilson; Madden, Robert E; Coleman, P L; Thompson, John R; Bixler, Alex; Lamppa, D C; McKenney, J L; Strizic, T; Johnson, D; Johns, O; Vigil, M P; Jones, B; Ampleford, D J; Savage, M E; Cuneo, M E; Jones, M C

    2013-06-01

    Tests are ongoing to conduct ~20 MA z-pinch implosions on the Z accelerator at Sandia National Laboratory using Ar, Kr, and D2 gas puffs as the imploding loads. The relatively high cost of operations on a machine of this scale imposes stringent requirements on the functionality, reliability, and safety of gas puff hardware. Here we describe the development of a prototype gas puff system including the multiple-shell nozzles, electromagnetic drivers for each nozzle's valve, a UV pre-ionizer, and an inductive isolator to isolate the ~2.4 MV machine voltage pulse present at the gas load from the necessary electrical and fluid connections made to the puff system from outside the Z vacuum chamber. This paper shows how the assembly couples to the overall Z system and presents data taken to validate the functionality of the overall system. PMID:23822342

  13. Architecture, implementation, and testing of a multiple-shell gas injection system for high current implosions on the Z accelerator

    SciTech Connect

    Krishnan, Mahadevan; Elliott, Kristi Wilson; Madden, Robert E.; Coleman, P. L.; Thompson, John R.; Bixler, Alex; Lamppa, D. C.; McKenney, J. L.; Strizic, T.; Johnson, D.; Johns, O.; Vigil, M. P.; Jones, B.; Ampleford, D. J.; Savage, M. E.; Cuneo, M. E.; Jones, M. C.

    2013-06-15

    Tests are ongoing to conduct {approx}20 MA z-pinch implosions on the Z accelerator at Sandia National Laboratory using Ar, Kr, and D{sub 2} gas puffs as the imploding loads. The relatively high cost of operations on a machine of this scale imposes stringent requirements on the functionality, reliability, and safety of gas puff hardware. Here we describe the development of a prototype gas puff system including the multiple-shell nozzles, electromagnetic drivers for each nozzle's valve, a UV pre-ionizer, and an inductive isolator to isolate the {approx}2.4 MV machine voltage pulse present at the gas load from the necessary electrical and fluid connections made to the puff system from outside the Z vacuum chamber. This paper shows how the assembly couples to the overall Z system and presents data taken to validate the functionality of the overall system.

  14. A novel beam focus control at the entrance to the ANU 14UD accelerator

    NASA Astrophysics Data System (ADS)

    De Cesare, M.; Weisser, D. C.; Fifield, L. K.; Tunningley, T. B.; Lobanov, N. R.

    2013-12-01

    Tandem electrostatic accelerators often require the flexibility to operate at variety of terminal voltages to cater for various user needs. However beam transmission will only be optimal for a limited range of terminal voltages. This paper describes a focussing system that greatly expands the range of terminal voltages for optimal transmission. This is achieved by controlling the gradient of the entrance of the low-energy tube providing an additional controllable focusing element. Up to 150 kV is applied to the fifth electrode of the first unit of the accelerator tube giving control of the tube entrance lens strength. Beam tests to confirm the efficacy of the lens have been performed. These tests demonstrate that the entrance lens control eliminates the need to short out sections of the tube for low terminal voltage operation.

  15. Protecting Accelerator Control Systems in the Face of Sophisticated Cyber Attacks

    SciTech Connect

    Hartman, Steven M

    2012-01-01

    Cyber security for industrial control systems has received significant attention in the past two years. The news coverage of the Stuxnet attack, believed to be targeted at the control system for a uranium enrichment plant, brought the issue to the attention of news media and policy makers. This has led to increased scrutiny of control systems for critical infrastructure such as power generation and distribution, and industrial systems such as chemical plants and petroleum refineries. The past two years have also seen targeted network attacks aimed at corporate and government entities including US Department of Energy National Laboratories. Both of these developments have potential repercussions for the control systems of particle accelerators. The need to balance risks from potential attacks with the operational needs of an accelerator present a unique challenge for the system architecture and access model.

  16. Investigation and Demonstration of Dry Carbon-Based Sorbent Injection for Mercury Control

    SciTech Connect

    Jim Butz; Terry Hunt

    2005-11-01

    Public Service Company of Colorado and ADA Technologies, Inc. have performed a study of the injection of activated carbon for the removal of vapor-phase mercury from coal-fired flue gas streams. The project was completed under contract to the US Department of Energy's National Energy Technology Laboratory, with contributions from EPRI and Public Service Company. The prime contractor for the project was Public Service Company, with ADA Technologies as the major subcontractor providing technical support to all aspects of the project. The research and development effort was conducted in two phases. In Phase I a pilot facility was fabricated and tests were performed using dry carbon-based sorbent injection for mercury control on a coal-fired flue gas slipstream extracted from an operating power plant. Phase II was designed to move carbon injection technology towards commercial application on coal-fired power plants by addressing key reliability and operability concerns. Phase II field work included further development work with the Phase I pilot and mercury measurements on several of PSCo's coal-fired generating units. In addition, tests were run on collected sorbent plus fly ash to evaluate the impact of the activated carbon sorbent on the disposal of fly ash. An economic analysis was performed where pilot plant test data was used to develop a model to predict estimated costs of mercury removal from plants burning western coals. Testing in the pilot plant was undertaken to quantify the effects of plant configuration, flue gas temperature, and activated carbon injection rate on mercury removal. All three variables were found to significantly impact the mercury removal efficiency in the pilot. The trends were clear: mercury removal rates increased with decreasing flue gas temperature and with increasing carbon injection rates. Mercury removal was much more efficient with reverse-gas and pulse-jet baghouse configurations than with an ESP as the particulate control device

  17. Development of a remote control console for the HHIRF 25-MV tandem accelerator

    SciTech Connect

    Hasanul Basher, A.M.

    1991-09-01

    The CAMAC-based control system for the 25-MV Tandem Accelerator at HHIRF uses two Perkin-Elmer, 32-bit minicomputers: a message-switching computer and a supervisory computer. Two operator consoles are located on one of the six serial highways. Operator control is provided by means of a console CRT, trackball, assignable shaft encoders and meters. The message-switching computer transmits and receives control information on the serial highways. At present, the CRT pages with updated parameters can be displayed and parameters can be controlled only from the two existing consoles, one in the Tandem control room and the other in the ORIC control room. It has become necessary to expand the control capability to several other locations in the building. With the expansion of control and monitoring capability of accelerator parameters to other locations, the operators will be able to control and observe the result of the control action at the same time. Since the new control console will be PC-based, the existing page format will be changed. The PC will be communicating with the Perkin-Elmer through RS-232 and a communication software package. Hardware configuration has been established, a communication software program that reads the pages from the shared memory has been developed. In this paper, we present the implementation strategy, works completed, existing and new page format, future action plans, explanation of pages and use of related global variables, a sample session, and flowcharts.

  18. A remote control console for the HHIRF 25-MV Tandem Accelerator

    SciTech Connect

    Hasanul Basher, A.M.

    1993-09-01

    The CAMAC-based control system for the 25-MV Tandem Accelerator at HHIRF uses two Perkin-Elmer, 32-bit minicomputers: a message-switching computer and a supervisory computer. Two operator consoles are located on one of the six serial highways. Operator control is provided by means of a console CRT, trackball, assignable shaft encoders, and meters. The message-switching computer transmits and receives control information on the serial highways. At present, the CRT pages with updated parameters can be displayed and parameters can be controlled only from the two existing consoles, one in the Tandem control room and the other in the ORIC control room. It has become necessary to expand the control capability to several other locations in the building. With the expansion of control and monitoring capability of accelerator parameters to other locations, the operators will be able to control and observe the result of the control action at the same time. This capability will be useful in the new Radioactive Ion Beam project of the division. Since the new control console will be PC-based, the existing page format will be changed. The PC will be communicating with the Perkin-Elmer through RS-232 with the aid of a communication protocol. Hardware configuration has been established, a software program that reads the pages from the shared memory, and a communication protocol have been developed. The following sections present the implementation strategy, work completed, future action plans, and the functional details of the communication protocol.

  19. Stabilization of Gyrotron Frequency by PID Feedback Control on the Acceleration Voltage

    NASA Astrophysics Data System (ADS)

    Khutoryan, E. M.; Idehara, T.; Kuleshov, A. N.; Tatematsu, Y.; Yamaguchi, Y.; Matsuki, Y.; Fujiwara, T.

    2015-12-01

    The results of frequency stabilization by proportional-integral-derivative (PID) feedback control of acceleration voltage in the 460-GHz Gyrotron FU CW GVI (the official name in Osaka University is Gyrotron FU CW GOI) are presented. The experiment was organized on the basis of the frequency modulation by modulation of acceleration voltage of beam electrons. The frequency stabilization during 10 h experiment was better than 10-6, which is compared with the results of the frequency deviation in free-running gyrotron operation.

  20. Persistence, localization, and external control of transgene expression after single injection of adeno-associated virus into injured joints.

    PubMed

    Lee, Hannah H; O'Malley, Michael J; Friel, Nicole A; Payne, Karin A; Qiao, Chunping; Xiao, Xiao; Chu, Constance R

    2013-04-01

    A single intra-articular injection of adeno-associated virus (AAV) results in stable and controllable transgene expression in normal rat knees. Because undamaged joints are unlikely to require treatment, the study of AAV delivery in joint injury models is crucial to potential therapeutic applications. This study tests the hypotheses that persistent and controllable AAV-transgene expression are (1) highly localized to the cartilage when AAV is injected postinjury and (2) localized to the intra-articular soft tissues when AAV is injected preinjury. Two AAV injection time points, postinjury and preinjury, were investigated in osteochondral defect and anterior cruciate ligament transection models of joint injury. Rats injected with AAV tetracycline response element (TRE)-luciferase received oral doxycycline for 7 days. Luciferase expression was evaluated longitudinally for 6 months. Transgene expression was persistent and controllable with oral doxycycline for 6 months in all groups. However, the location of transgene expression was different: postinjury AAV-injected knees had luciferase expression highly localized to the cartilage, while preinjury AAV-injected knees had more widespread signal from intra-articular soft tissues. The differential transgene localization between preinjury and postinjury injection can be used to optimize treatment strategies. Highly localized postinjury injection appears advantageous for treatments targeting repair cells. The more generalized and controllable reservoir of transgene expression following AAV injection before anterior cruciate ligament transection (ACLT) suggests an intriguing concept for prophylactic delivery of joint protective factors to individuals at high risk for early osteoarthritis (OA). Successful external control of intra-articular transgene expression provides an added margin of safety for these potential clinical applications. PMID:23496155

  1. Pilot scale-SO{sub 2} control by dry sodium bicarbonate injection and an electrostatic precipitator

    SciTech Connect

    Pliat, M.J.; Wilder, J.M.

    2007-10-15

    A 500 actual cubic feet gas per minute (acfm) pilot-scale SO{sub 2} control study was undertaken to investigate flue gas desulfurization (FGD) by dry sodium sorbents in 400{sup o}F (204.5{sup o}C) flue gases emitted from a coal fired boiler with flue gas concentrations between 350 and 2500 ppm SO{sub 2}. Powdered sodium alkaline reagents were injected into the hot flue gas downstream of the air preheater and the spent reagents were collected using an electrostatic precipitator. Three different sorbents were used: processed sodium bicarbonate of two particle sizes; solution mined sodium bicarbonate, and processed sodium sesquicarbonate. SO{sub 2} concentrations were measured upstream of the reagent injection, 25-ft (7.62 m) downstream of the injection point, and downstream of the electrostatic precipitator. SO{sub 2} collection efficiencies ranged from 40 to 80% using sodium bicarbonate stoichiometric ratios from 0.5 to 3.0. Much of the in-duct SO{sub 2} removal occurred during the first second of reagent reaction time, indicating that the sulfur dioxide-sodium reaction rates may be faster than have been measured for fixed bed measurements reported in the literature.

  2. Two-pulse ionization injection into quasilinear laser wakefields.

    PubMed

    Bourgeois, N; Cowley, J; Hooker, S M

    2013-10-11

    We describe a scheme for controlling electron injection into the quasilinear wakefield driven by a guided drive pulse via ionization of a dopant species by a collinear injection laser pulse with a short Rayleigh range. The scheme is analyzed by particle-in-cell simulations which show controlled injection and acceleration of electrons to an energy of 370 MeV, a relative energy spread of 2%, and a normalized transverse emittance of 2.0 μm. PMID:24160608

  3. Control of Laser Plasma Based Accelerators up to 1 GeV

    SciTech Connect

    Nakamura, Kei

    2007-12-03

    This dissertation documents the development of a broadband electron spectrometer (ESM) for GeV class Laser Wakefield Accelerators (LWFA), the production of high quality GeV electron beams (e-beams) for the first time in a LWFA by using a capillary discharge guide (CDG), and a statistical analysis of CDG-LWFAs. An ESM specialized for CDG-LWFAs with an unprecedented wide momentum acceptance, from 0.01 to 1.1 GeV in a single shot, has been developed. Simultaneous measurement of e-beam spectra and output laser properties as well as a large angular acceptance (> {+-} 10 mrad) were realized by employing a slitless scheme. A scintillating screen (LANEX Fast back, LANEX-FB)--camera system allowed faster than 1 Hz operation and evaluation of the spatial properties of e-beams. The design provided sufficient resolution for the whole range of the ESM (below 5% for beams with 2 mrad divergence). The calibration between light yield from LANEX-FB and total charge, and a study on the electron energy dependence (0.071 to 1.23 GeV) of LANEX-FB were performed at the Advanced light source (ALS), Lawrence Berkeley National Laboratory (LBNL). Using this calibration data, the developed ESM provided a charge measurement as well. The production of high quality electron beams up to 1 GeV from a centimeter-scale accelerator was demonstrated. The experiment used a 310 {micro}m diameter gas-filled capillary discharge waveguide that channeled relativistically-intense laser pulses (42 TW, 4.5 x 10{sup 18} W/cm{sup 2}) over 3.3 centimeters of sufficiently low density ({approx_equal} 4.3 x 10{sup 18}/cm{sup 3}) plasma. Also demonstrated was stable self-injection and acceleration at a beam energy of {approx_equal} 0.5 GeV by using a 225 {micro}m diameter capillary. Relativistically-intense laser pulses (12 TW, 1.3 x 10{sup 18}W/cm{sup 2}) were guided over 3.3 centimeters of low density ({approx_equal} 3.5 x 10{sup 18}/cm{sup 3}) plasma in this experiment. A statistical analysis of the CDG

  4. Control of laser-wakefield acceleration by the plasma-density profile.

    PubMed

    Pukhov, A; Kostyukov, I

    2008-02-01

    We show that both the maximum energy gain and the accelerated beam quality can be efficiently controlled by the plasma-density profile. Choosing a proper density gradient one can uplift the dephasing limitation and keep the phase synchronism between the bunch of relativistic particles and the plasma wave over extended distances. Putting electrons into the n th wake period behind the driving laser pulse, the maximum energy gain is increased by the factor, which is proportional to n, over that in the case of uniform plasma. Layered plasma is suggested to keep the resonant condition for laser-wakefield excitation. The acceleration is limited then by laser depletion rather than by dephasing. Further, we show that the natural energy spread of the particle bunch acquired at the acceleration stage can be effectively removed by a matched deceleration stage, where a larger plasma density is used. PMID:18352081

  5. The evolution of tooling, techniques, and quality control for accelerator dipole magnet cables

    SciTech Connect

    Scanlan, R.M.

    1992-08-01

    The present generation of particle accelerators are utilizing the flattened, compacted, single layer cable design introduced nearly 20 years ago at Rutherford Laboratory. However, the requirements for current density, filament size, dimensional control long lengths, and low current degradation are much more stringent for the present accelerators compared with the earlier Tevatron and HERA accelerators. Also, in order to achieve higher field strengths with efficient use of superconductor, the new designs require wider cables with more strands. These requirements have stimulated an active research effort which has led to significant improvements in critical current density and conductor manufacturing. In addition they have stimulated the development of new cabling techniques, improved tooling, and better measurement techniques. The need to produce over 20 million meters of cable has led to the development of high speed cabling machines and on-line quality assurance measurements. These new developments will be discussed, and areas still requiring improvement will be identified.

  6. Laser acceleration and its future.

    PubMed

    Tajima, Toshiki

    2010-01-01

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

  7. Laser acceleration and its future

    PubMed Central

    Tajima, Toshiki

    2010-01-01

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

  8. Multi-cavity complex controller with vector simulator for TESLA technology linear accelerator

    NASA Astrophysics Data System (ADS)

    Czarski, Tomasz; Pozniak, Krzysztof T.; Romaniuk, Ryszard S.; Szewinski, Jaroslaw

    2008-01-01

    A digital control, as the main part of the Low Level RF system, for superconducting cavities of a linear accelerator is presented. The FPGA based controller, supported by MATLAB system, was developed to investigate a novel firmware implementation. The complex control algorithm based on the non-linear system identification is the proposal verified by the preliminary experimental results. The general idea is implemented as the Multi-Cavity Complex Controller (MCC) and is still under development. The FPGA based controller executes procedure according to the prearranged control tables: Feed-Forward, Set-Point and Corrector unit, to fulfill the required cavity performance: driving in the resonance during filling and field stabilization for the flattop range. Adaptive control algorithm is applied for the feed-forward and feedback modes. The vector Simulator table has been introduced for an efficient verification of the FPGA controller structure. Experimental results of the internal simulation, are presented for a cavity representative condition.

  9. The Datacon Master -- Renovation of a Datacon field bus communications system for accelerator control

    SciTech Connect

    Kerner, T.M.

    1995-05-01

    The Datacon system is a serial coaxial transformer isolated communication field bus system used to control and monitor accelerator remote devices. The Datacon field bus has been a BNL accelerator standard since its initial use in 1965. A single Datacon field bus supports up to 256 devices on a multidrop RG62A/U coaxial cable with up to 33 devices or 2,000 feet between repeaters or buffered branches. The forcing factor to renovate was the inability to repair the aging PDP-8E and PDP10 computers. The maintenance on this aging system was costly and the large number of accelerator devices dependent on the Datacon system could not be converted in a reasonable period of time to a new modern field bus. A commercial VMEbus host CPU mated with a custom designed VMEbus SBC event driven serial communications engine featuring a superscaler RISC 32-bit Intel i960 CPU met the design challenge. The commercial VMEbus host runs the VxWorks real-time operating system and connects to UNIX workstations over a Ethernet LAN. The V110 Datacon Master is the custom designed front end computer that integrates an accelerator event time line system with accelerator devices for up to 8 ppm users adding new capabilities.

  10. Economical launching and accelerating control strategy for a single-shaft parallel hybrid electric bus

    NASA Astrophysics Data System (ADS)

    Yang, Chao; Song, Jian; Li, Liang; Li, Shengbo; Cao, Dongpu

    2016-08-01

    This paper presents an economical launching and accelerating mode, including four ordered phases: pure electrical driving, clutch engagement and engine start-up, engine active charging, and engine driving, which can be fit for the alternating conditions and improve the fuel economy of hybrid electric bus (HEB) during typical city-bus driving scenarios. By utilizing the fast response feature of electric motor (EM), an adaptive controller for EM is designed to realize the power demand during the pure electrical driving mode, the engine starting mode and the engine active charging mode. Concurrently, the smoothness issue induced by the sequential mode transitions is solved with a coordinated control logic for engine, EM and clutch. Simulation and experimental results show that the proposed launching and accelerating mode and its control methods are effective in improving the fuel economy and ensure the drivability during the fast transition between the operation modes of HEB.

  11. Plasma gradient controlled injection and postacceleration of high quality electron bunches

    SciTech Connect

    Geddes, Cameron G.R.; Nakamura, Kei; Plateau, Guillaume R.; Toth, Csaba; Cormier-Michel, Estelle; Esarey, Eric; Schroeder, Carl B.; Cary, John R.; Leemans, Wim P.; Bruhwiler, D.L.

    2008-10-15

    Plasma density gradients in a gas jet were used to control the wake phase velocity and trapping threshold in a laser wakefield accelerator, producing stable electron bunches with longitudinal and transverse momentum spreads more than 10 times lower than in previous experiments (0.17 and 0.02 MeV=c FWHM, respectively) and with central momenta of 0.76 +- 0.02 MeV=c. Transition radiation measurements combined with simulations indicated that the bunches can be used as a wakefieldaccelerator injector to produce stable beams with 0.2 MeV=c-class momentum spread at high energies.

  12. Controlled, sustained release of proteins via an injectable, mineral-coated microsphere delivery vehicle

    NASA Astrophysics Data System (ADS)

    Franklin-Ford, Travelle

    Hydroxyapatite interfaces have demonstrated strong protein binding and protein selection from a passing solution and can serve as a biocompatible carrier for controlled protein delivery. Hydroxyapatite is a major component of long bones and tooth enamel and is the most stable of all calcium phosphate isoforms in aqueous solutions at physiologic pH, providing a sensitive chromatographic mechanism for separating proteins. Here we describe an approach to create a synthetic hydroxyapatite coating through a biomimetic, heterogeneous nucleation from a modified simulated body fluid--supersaturated with calcium and phosphate ions on the surface of injectable polymer microspheres. We are able to bind and release bioactive growth factors into a variety of in vitro and in vivo conditions, demonstrating the functionality and advantage of the biomaterial. Creating a hydroxyapatite layer on the Poly(D,L-lactide-co-glycolide) (PLG) microsphere surface, avails the microsphere interior for another application that will not compete with protein binding and release. Encapsulating an imaging agent within the aqueous phase of the emulsion provides a visual reference for the injectable therapy upon microsphere fabrication. Another advantage of this system is that the mineral coating and subsequent protein binding is not compromised by the encapsulated imaging agent. This dual function delivery vehicle is not only advantageous for spatial tracking therapeutic applications, but also determining the longevity of the delivery vehicle once injected. In the broader sense, providing a mechanism to image and track our temporally controlled, sustained delivery system gives more evidence to support the effects of released protein on in vivo responses (bioactivity) and locate microspheres within different biological systems.

  13. Pellet injection technology

    NASA Astrophysics Data System (ADS)

    Combs, S. K.

    1993-07-01

    During the last 10 to 15 years, significant progress has been made worldwide in the area of pellet injection technology. This specialized field of research originated as a possible solution to the problem of depositing atoms of fuel deep within magnetically confined, hot plasmas for refueling of fusion power reactors. Using pellet injection systems, frozen macroscopic (millimeter-size) pellets composed of the isotopes of hydrogen are formed, accelerated, and transported to the plasma for fueling. The process and benefits of plasma fueling by this approach have been demonstrated conclusively on a number of toroidal magnetic confinement configurations; consequently, pellet injection is the leading technology for deep fueling of magnetically confined plasmas for controlled thermonuclear fusion research. Hydrogen pellet injection devices operate at very low temperatures (≂10 K) at which solid hydrogen ice can be formed and sustained. Most injectors use conventional pneumatic (light gas gun) or centrifuge (mechanical) acceleration concepts to inject hydrogen or deuterium pellets at speeds of ≂1-2 km/s. Pellet injectors that can operate at quasi-steady state (pellet delivery rates of 1-40 Hz) have been developed for long-pulse fueling. The design and operation of injectors with the heaviest hydrogen isotope, tritium, offer some special problems because of tritium's radioactivity. To address these problems, a proof-of-principle experiment was carried out in which tritium pellets were formed and accelerated to speeds of 1.4 km/s. Tritium pellet injection is scheduled on major fusion research devices within the next few years. Several advanced accelerator concepts are under development to increase the pellet velocity. One of these is the two-stage light gas gun, for which speeds of slightly over 4 km/s have already been reported in laboratory experiments with deuterium ice. A few two-stage pneumatic systems (single-shot) have recently been installed on tokamak

  14. Controlled Release of Chemotherapeutic Platinum-Bisphosphonate Complexes from Injectable Calcium Phosphate Cements.

    PubMed

    Farbod, Kambiz; Sariibrahimoglu, Kemal; Curci, Alessandra; Hayrapetyan, Astghik; Hakvoort, Jan N W; van den Beucken, Jeroen J J P; Iafisco, Michele; Margiotta, Nicola; Leeuwenburgh, Sander C G

    2016-05-01

    Herein, we present a method to release chemotherapeutic platinum-bisphosphonate (Pt-BP) complexes from apatitic calcium phosphate cements (CPCs). Pt-BP-loaded hydroxyapatite nanoparticles (HA NPs) were added at different ratios to the powder phase of the cements, which contained poly(D,L-lactic-co-glycolic acid) (PLGA) microspheres as porogens to accelerate their degradation. In vitro release kinetics of Pt-BP complexes revealed that the release rate of Pt species can be tuned by varying the amount of drug-loaded HA NPs as well as modifying the chemical structure of the Pt-BP complex to tailor its affinity with HA NPs. In addition, the incorporation of PLGA microspheres into the CPCs increased the degradation rate of the materials without affecting the release rate of Pt species. Finally, the antiproliferative activity of the free Pt-BP complexes and Pt-BP-loaded CPCs was evaluated using both human osteosarcoma cancer cells (MG-63) and human bone marrow-derived mesenchymal stromal cells (h-BMMSCs). This study demonstrated that both free Pt-BP complexes and the releasates from the CPCs were antiproliferative in a dose-dependent manner. Moreover, their antiproliferative activity was higher on MG-63 cells compared to h-BMMSC primary cells. In summary, it was shown that injectable CPCs can be rendered chemotherapeutically active by incorporation of HA NPs loaded with HA-binding Pt-BP complexes. PMID:27083055

  15. Transmission of Real World Force Sensation by Micro/Macro Bilateral Control Based on Acceleration Control with Standardization Matrix

    NASA Astrophysics Data System (ADS)

    Shimono, Tomoyuki; Katsura, Seiichiro; Susa, Shigeru; Takei, Takayoshi; Ohnishi, Kouhei

    This paper proposes novel micro/macro bilateral control based on acceleration control with standardization matrix. In bilateral control, force control and position control should be realized simultaneously. However, they are not able to be realized in one real axis at the same time. Thus, force control and position control are realized in virtual mode space in this paper. Then, the proposed standardization matrix is able to harmonize the standard of macro master system with the standard of micro slave system in the virtual mode space. With the proposed method, the transmission of force sensation from the real micro environment is realized. The experimental results are shown to verify the viability of the proposed method.

  16. Introducing a new paradigm for accelerators and large experimental apparatus control systems

    NASA Astrophysics Data System (ADS)

    Catani, L.; Zani, F.; Bisegni, C.; Di Pirro, G.; Foggetta, L.; Mazzitelli, G.; Stecchi, A.

    2012-11-01

    The integration of web technologies and web services has been, in the recent years, one of the major trends in upgrading and developing distributed control systems for accelerators and large experimental apparatuses. Usually, web technologies have been introduced to complement the control systems with smart add-ons and user friendly services or, for instance, to safely allow access to the control system to users from remote sites. Despite this still narrow spectrum of employment, some software technologies developed for high-performance web services, although originally intended and optimized for these particular applications, deserve some features suggesting a deeper integration in a control system and, eventually, their use to develop some of the control system’s core components. In this paper, we present the conceptual design of a new control system for a particle accelerator and associated machine data acquisition system, based on a synergic combination of a nonrelational key/value database and network distributed object caching. The use of these technologies, to implement respectively continuous data archiving and data distribution between components, brought about the definition of a new control system concept offering a number of interesting features such as a high level of abstraction of services and components and their integration in a framework that can be seen as a comprehensive service provider that both graphical user interface applications and front-end controllers join for accessing and, to some extent, expanding its functionalities.

  17. Injectable alginate hydrogel for enhanced spatiotemporal control of lentivector delivery in murine skeletal muscle.

    PubMed

    Stilhano, Roberta S; Madrigal, Justin L; Wong, Kevin; Williams, Priscilla A; Martin, Priscila K M; Yamaguchi, Fabio S M; Samoto, Vivian Y; Han, Sang W; Silva, Eduardo A

    2016-09-10

    Hydrogels are an especially appealing class of biomaterials for gene delivery vehicles as they can be introduced into the body with minimally invasive procedures and are often applied in tissue engineering and regenerative medicine strategies. In this study, we show for the first time the use of an injectable alginate hydrogel for controlled delivery of lentivectors in the skeletal muscle of murine hindlimb. We propose to alter the release rates of lentivectors through manipulation of the molecular weight distribution of alginate hydrogels. The release of lentivector was tested using two different ratios of low and high molecular weight (MW) alginate polymers (75/25 and 25/75 low/high MW). The interdependency of lentivector release rate and alginate degradation rate was assessed in vitro. Lentivector-loaded hydrogels maintained transduction potential for up to one week in vitro as demonstrated by the continual transduction of HEK-293T cells. Injection of lentivector-loaded hydrogel in vivo led to a sustained level of transgene expression for more than two months while minimizing the copies of lentivirus genome inserted into the genome of murine skeletal muscle cells. This strategy of spatiotemporal control of lentivector delivery from alginate hydrogels may provide a versatile tool to combine gene therapy and biomaterials for applications in regenerative medicine. PMID:27374631

  18. Asynchronous data change notification between database server and accelerator controls system

    SciTech Connect

    Fu, W.; Morris, J.; Nemesure, S.

    2011-10-10

    Database data change notification (DCN) is a commonly used feature. Not all database management systems (DBMS) provide an explicit DCN mechanism. Even for those DBMS's which support DCN (such as Oracle and MS SQL server), some server side and/or client side programming may be required to make the DCN system work. This makes the setup of DCN between database server and interested clients tedious and time consuming. In accelerator control systems, there are many well established software client/server architectures (such as CDEV, EPICS, and ADO) that can be used to implement data reflection servers that transfer data asynchronously to any client using the standard SET/GET API. This paper describes a method for using such a data reflection server to set up asynchronous DCN (ADCN) between a DBMS and clients. This method works well for all DBMS systems which provide database trigger functionality. Asynchronous data change notification (ADCN) between database server and clients can be realized by combining the use of a database trigger mechanism, which is supported by major DBMS systems, with server processes that use client/server software architectures that are familiar in the accelerator controls community (such as EPICS, CDEV or ADO). This approach makes the ADCN system easy to set up and integrate into an accelerator controls system. Several ADCN systems have been set up and used in the RHIC-AGS controls system.

  19. Intravitreal injection

    MedlinePlus

    Retinal vein occlusion-intravitreal injection; Triamcinolone-intravitreal injection; Dexamethasone-intravitreal injection; Lucentis-intravitreal injection; Avastin-intravitreal injection; Bevacizumab-intravitreal injection; Ranibizumab- ...

  20. Muon Acceleration - RLA and FFAG

    SciTech Connect

    Bogacz, Alex

    2011-10-01

    Various acceleration schemes for muons are presented. The overall goal of the acceleration systems: large acceptance acceleration to 25 GeV and 'beam shaping' can be accomplished by various fixed field accelerators at different stages. They involve three superconducting linacs: a single pass linear Pre-accelerator followed by a pair of multi-pass Recirculating Linear Accelerators (RLA) and finally a non-scaling FFAG ring. The present baseline acceleration scenario has been optimized to take maximum advantage of appropriate acceleration scheme at a given stage. The solenoid based Pre-accelerator offers very large acceptance and facilitates correction of energy gain across the bunch and significant longitudinal compression trough induced synchrotron motion. However, far off-crest acceleration reduces the effective acceleration gradient and adds complexity through the requirement of individual RF phase control for each cavity. The RLAs offer very efficient usage of high gradient superconducting RF and ability to adjust path-length after each linac pass through individual return arcs with uniformly periodic FODO optics suitable for chromatic compensation of emittance dilution with sextupoles. However, they require spreaders/recombiners switchyards at both linac ends and significant total length of the arcs. The non-scaling Fixed Field Alternating Gradient (FFAG) ring combines compactness with very large chromatic acceptance (twice the injection energy) and it allows for large number of passes through the RF (at least eight, possibly as high as 15).

  1. INVESTIGATION AND DEMONSTRATION OF DRY CARBON-BASED SORBENT INJECTION FOR MERCURY CONTROL

    SciTech Connect

    Terry Hunt; Mark Fox; Lillian Stan; Sheila Haythornthwaite; Justin Smith; Jason Ruhl

    1998-10-01

    This quarterly report describes the activities that have taken place during the first full quarter of the Phase II project ''Investigation and Demonstration of Dry Carbon-Based Sorbent Injection for Mercury Control''. Modifications were completed and sampling began at the 600 acfm pilot-scale particulate control module (PCM) located at the Comanche Station in Pueblo, CO. The PCM was configured as an electrostatic precipitator for these tests. A Perkin-Elmer flue gas mercury analyzer was installed on-site and operated. Initial test results using both manual sampling methodology and the mercury analyzer are presented herein. Preparations were made during this period for full-scale mercury testing of several PSCo units. A site visit was made to Arapahoe and Cherokee Generating Stations to determine sample locations and to develop a test plan.

  2. Prediction of force and acceleration control spectra for Space Shuttle orbiter sidewall-mounted payloads

    NASA Technical Reports Server (NTRS)

    Hipol, Philip J.

    1990-01-01

    The development of force and acceleration control spectra for vibration testing of Space Shuttle (STS) orbiter sidewall-mounted payloads requiresreliable estimates of the sidewall apparent weight and free (i.e. unloaded) vibration during lift-off. The feasibility of analytically predicting these quantities has been investigated through the development and analysis of a finite element model of the STS cargo bay. Analytical predictions of the sidewall apparent weight were compared with apparent weight measurements made on OV-101, and analytical predictions of the sidewall free vibration response during lift-off were compared with flight measurements obtained from STS-3 and STS-4. These analysis suggest that the cargo bay finite element model has potential application for the estimation of force and acceleration control spectra for STS sidewall-mounted payloads.

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

    SciTech Connect

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

    2009-05-04

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

  4. Optical control of electron phase space in plasma accelerators with incoherently stacked laser pulses

    SciTech Connect

    Kalmykov, S. Y. Shadwick, B. A.; Davoine, X.; Lehe, R.; Lifschitz, A. F.

    2015-05-15

    It is demonstrated that synthesizing an ultrahigh-bandwidth, negatively chirped laser pulse by incoherently stacking pulses of different wavelengths makes it possible to optimize the process of electron self-injection in a dense, highly dispersive plasma (n{sub 0}∼10{sup 19} cm{sup −3}). Avoiding transformation of the driving pulse into a relativistic optical shock maintains a quasi-monoenergetic electron spectrum through electron dephasing and boosts electron energy far beyond the limits suggested by existing scaling laws. In addition, evolution of the accelerating bucket in a plasma channel is shown to produce a background-free, tunable train of femtosecond-duration, 35–100 kA, time-synchronized quasi-monoenergetic electron bunches. The combination of the negative chirp and the channel permits acceleration of electrons beyond 1 GeV in a 3 mm plasma with 1.4 J of laser pulse energy, thus offering the opportunity of high-repetition-rate operation at manageable average laser power.

  5. Injectable polyanhydride granules provide controlled release of water-soluble drugs with a reduced initial burst.

    PubMed

    Tabata, Y; Domb, A; Langer, R

    1994-01-01

    A method for preparing polyanhydride granules of an injectable size was developed. The resulting granules permitted a nearly constant release of low-molecular-weight, water-soluble drugs without an initial burst. The polyanhydrides used were poly(fatty acid dimer), poly(sebacic acid), and their copolymers. The dyes acid orange 63 and p-nitroaniline were used as model compounds for drugs. Polymer degradation and drug release for disks and variously sized granules of copolymers containing drugs, prepared by a water-in-oil (W/O) emulsion method, were compared with those for devices prepared by the usual compression method. In the W/O emulsion method, a mixture of aqueous drug solution and polymer-chloroform solution was emulsified by probe sonication to prepare a very fine W/O emulsion. The powder obtained by freeze-drying of the W/O emulsion was pressed into circular disks. In the compression method, the drug was mechanically mixed with the polymer, and the mixture was compressed into circular disks. The resulting disks were ground to prepare granules of different sizes. The granules encapsulated more than 95% of the drug, irrespective of the preparation method. Both methods were effective in preparing polymer disks capable of controlled drug release without any initial burst. However, as the granule size decreased to an injectable size (diameter, < 150 microns), a large difference in the drug release profile was observed between the two preparation methods. The injectable granules obtained by the W/O emulsion method showed nearly constant drug release without any large initial burst, in contrast to those prepared by the compression method, irrespective of the drug type.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8138910

  6. Towards optical polarization control of laser-driven proton acceleration in foils undergoing relativistic transparency.

    PubMed

    Gonzalez-Izquierdo, Bruno; King, Martin; Gray, Ross J; Wilson, Robbie; Dance, Rachel J; Powell, Haydn; Maclellan, David A; McCreadie, John; Butler, Nicholas M H; Hawkes, Steve; Green, James S; Murphy, Chris D; Stockhausen, Luca C; Carroll, David C; Booth, Nicola; Scott, Graeme G; Borghesi, Marco; Neely, David; McKenna, Paul

    2016-01-01

    Control of the collective response of plasma particles to intense laser light is intrinsic to relativistic optics, the development of compact laser-driven particle and radiation sources, as well as investigations of some laboratory astrophysics phenomena. We recently demonstrated that a relativistic plasma aperture produced in an ultra-thin foil at the focus of intense laser radiation can induce diffraction, enabling polarization-based control of the collective motion of plasma electrons. Here we show that under these conditions the electron dynamics are mapped into the beam of protons accelerated via strong charge-separation-induced electrostatic fields. It is demonstrated experimentally and numerically via 3D particle-in-cell simulations that the degree of ellipticity of the laser polarization strongly influences the spatial-intensity distribution of the beam of multi-MeV protons. The influence on both sheath-accelerated and radiation pressure-accelerated protons is investigated. This approach opens up a potential new route to control laser-driven ion sources. PMID:27624920

  7. Optimization and beam control in large-emittance accelerators: Neutrino factories;

    SciTech Connect

    Carol Johnstone

    2004-08-23

    Schemes for intense sources of high-energy muons require collection, rf capture, and transport of particle beams with unprecedented emittances, both longitudinally and transversely. These large emittances must be reduced or ''cooled'' both in size and in energy spread before the muons can be efficiently accelerated. Therefore, formation of muon beams sufficiently intense to drive a Neutrino Factory or Muon Collider requires multi-stage preparation. Further, because of the large beam phase space which must be successfully controlled, accelerated, and transported, the major stages that comprise such a facility: proton driver, production, capture, phase rotation, cooling, acceleration, and storage are complex and strongly interlinked. Each of the stages must be consecutively matched and simultaneously optimized with upstream and downstream systems, meeting challenges not only technically in the optics and component design, but also in the modeling of both new and extended components. One design for transverse cooling, for example, employs meter-diameter solenoids to maintain strong focusing--300-500 mr beam divergences--across ultra-large momentum ranges, {ge} {+-}20% {delta}p/p, defying conventional approximations to the dynamics and field representation. To now, the interplay of the different systems and staging strategies has not been formally addressed. This work discusses two basic, but different approaches to a Neutrino Factory and how the staging strategy depends on beam parameters and method of acceleration.

  8. Improved plasma accelerator

    NASA Technical Reports Server (NTRS)

    Cheng, D. Y.

    1971-01-01

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

  9. The Value of Safflower Yellow Injection for the Treatment of Acute Cerebral Infarction: A Randomized Controlled Trial

    PubMed Central

    Li, Le-Jun; Li, Yu-Mei; Qiao, Ben-Yu; Jiang, Shan; Li, Xin; Du, Hong-Ming; Han, Peng-Cheng; Shi, Jiong

    2015-01-01

    Background. Safflower Yellow Injection has been reported as a treatment for acute cerebral infarction in recent studies in China. However, there is a lack of availability of the evidence for the efficacy and safety of Safflower Yellow Injection for the treatment of acute ischemic stroke. So we investigated the effects of Safflower Yellow Injection for the treatment of acute cerebral infarction. Method. All subjects were randomly divided into Safflower Yellow Injection group given Safflower Yellow Injection (80 mg) and control group given placebo (0 mg) injection by intravenous drop once daily for 14 days. National Institute of Health Stroke Scale (NIHSS); hemorheological detection; coagulation function; and serum inflammatory markers, tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6), were used to investigate the effects before and 14 days after the treatment. Results. The scores of NIHSS were decreased on day 7 and day 14 after treatment. The hemorheological index of RBC deformation and RBC aggregation were significantly improved, prothrombin time (PT) increased, and fibrinogen (FIB) and TNF-α, IL-1β, and IL-6 were decreased in patients treated with Safflower Yellow injection on day 14 after treatment (P < 0.05). Conclusion. Data suggests that Safflower Yellow Injection therapy may be beneficial for acute cerebral infarction. PMID:26074992

  10. Rapid control of mold temperature during injection molding process: Effect of packing pressure

    NASA Astrophysics Data System (ADS)

    Liparoti, Sara; Sorrentino, Andrea; Titomanlio, Giuseppe

    2015-12-01

    A thorough analysis of the effect of operative conditions of injection molding process on the morphology distribution inside the obtained molded is performed, with particular reference to semi- crystalline polymers. In particular, fully characterized injection molding tests are presented using an isotactic polypropylene, previously carefully characterized as far as most of properties of interest. The effects of mold temperature and packing conditions are analyzed. The mold temperature was controlled by a thin heating device, composed by polyimide as insulating layer and polyimide loaded carbon black as electrical conductive layer, that is able to increase temperature on mold surface in few seconds (70°C/s) by joule effect and cool down soon after. The shear layer thickness in the molded is reduced in the samples produced at high mold temperatures, that means high electrical power and long heating time, and this reduction is more significant at lower packing pressures, indeed, at 360bar as packing pressure and 20s as heating time the shear layer disappear. The resulting morphology was analyzed by optical microscope.

  11. FUEL FORMULATION EFFECTS ON DIESEL FUEL INJECTION, COMBUSTION, EMISSIONS AND EMISSION CONTROL

    SciTech Connect

    Boehman, A; Alam, M; Song, J; Acharya, R; Szybist, J; Zello, V; Miller, K

    2003-08-24

    This paper describes work under a U.S. DOE sponsored Ultra Clean Fuels project entitled ''Ultra Clean Fuels from Natural Gas,'' Cooperative Agreement No. DE-FC26-01NT41098. In this study we have examined the incremental benefits of moving from low sulfur diesel fuel and ultra low sulfur diesel fuel to an ultra clean fuel, Fischer-Tropsch diesel fuel produced from natural gas. Blending with biodiesel, B100, was also considered. The impact of fuel formulation on fuel injection timing, bulk modulus of compressibility, in-cylinder combustion processes, gaseous and particulate emissions, DPF regeneration temperature and urea-SCR NOx control has been examined. The primary test engine is a 5.9L Cummins ISB, which has been instrumented for in-cylinder combustion analysis and in-cylinder visualization with an engine videoscope. A single-cylinder engine has also been used to examine in detail the impacts of fuel formulation on injection timing in a pump-line-nozzle fueling system, to assist in the interpretation of results from the ISB engine.

  12. Fabrication and modelling of injection moulded all-polymer capillary microvalves for passive microfluidic control

    NASA Astrophysics Data System (ADS)

    Kistrup, Kasper; Esben Poulsen, Carl; Østergaard, Peter Friis; Haugshøj, Kenneth Brian; Taboryski, Rafael; Wolff, Anders; Fougt Hansen, Mikkel

    2014-12-01

    Rapid prototyping is desirable when developing products. One example of such a product is all-polymer, passive flow controlled lab-on-a-chip systems that are preferential when developing low-cost disposable chips for point-of-care use. In this paper we investigate the following aspects of going from rapid prototyping to pilot (mass) production. (1) Fabrication of an all-polymer microfluidic system using a rapid prototyped master insert for injection moulding and ultrasonic welding, including a systematic experimental characterisation of chip featured geometric capillary microvalve test structures. (2) Numerical modelling of the microvalve burst pressures. Numerical modelling of burst pressures is challenging due to its non-equilibrium nature. We have implemented and tested the level-set method modified with a damped driving term and show that the introduction of the damping term leads to numerically robust results with limited computational demands and a low number of iterations. Numerical and simplified analytical results are validated against the experimental results. We find that injection moulding and ultrasonic welding are effective for chip production and that the experimental burst pressures could be estimated with an average accuracy of 5% using the presented numerical model.

  13. (The control of microstructures during consolidation and injection molding of colloidal dispersions)

    SciTech Connect

    Not Available

    1991-01-01

    The existing three-year grant pertaining to The control of micro-structures during consolidation and injection molding of colloidal dispersions'' began July 1, 1988 as a continuation of a previous grant. The overall effort seeks to answer fundamental questions relevant to the colloidal processing of submicron particles leading to ceramic materials for strutural, electronic, or optical applications. At the outset two distinct projects were envisioned, an exploration of the ultrasonic enhancement of disorder-order transitions and a detailed study of injection molding of very dense dispersion, with each weighted toward experiments but with theoretical components. As the effort evolved the focus shifted in response to the interests of the students attracted to the project, the identification of interesting related problems through technical meetings, and different insights gained during participation in a DOE sponsored workshop. The scope that has emerged encompasses: completion of research begun during the first grant period on disorder-order transitions occurring during sedimentation, the consolidation of flocculated dispersions via filtration and the assembly of nanometer-sized particle into dense packings.

  14. Prevention, control and treatment of HIV-AIDS among injecting drug use in Bandung, Indonesia.

    PubMed

    Alisjahbana, Bachti; Susanto, Herman; Roesli, Rully; Yusuf, Hadi; Hinduan, Zahrotur; Mase, Johannes C; Surahman, Eri; van der Ven, Andre

    2009-07-01

    Indonesia is facing a growing HIV-epidemic that in many areas is driven by injecting drug use (IDU). IDUs underutilize health services, partly because of legal aspects which also cause that many are held in prison, where further HIV- transmission may take place. Most HIV-infected patients present with advanced HIV-AIDS and many deaths before starting antiretroviral treatment. The growing HIV-epidemic in Indonesia has socio-economical implications for individual patients as well as for the health system and for society. IMPACT, a multidisciplinary university-based program in Bandung, West-Java, integrates HIV-prevention and treatment, combining research and implementation. Biomedical, public health and sociobehavioral expertise is used for educational programs for adolescents; scaling-up HIV-testing, harm reduction strategies and care for HIV/AIDS in hospital, community and prison; and institutional as well as individual capacity building related to IDU and HIV/AIDS. It is expected that these activities can make a significant contribution to control of HIV-AIDS in the context of injecting drug use in West-Java and Indonesia as a whole. PMID:19920301

  15. [Experiences with pain control during piglet castration in Switzerland Part 2: Injection anesthesia].

    PubMed

    Enz, A; Schüpbach-Regula, G; Bettschart, R; Fuschini, E; Bürgi, E; Sidler, X

    2013-12-01

    The aim of this study was to describe the practical implementation of the painless castration under injection anaesthesia in Switzerland. 30 swine farms were visited and 60 farmers answered a questionnaire. 34 % of the piglets showed movements during castration under injection anaesthesia and 17 % had excitations during recovery from anaesthesia. After 48 minutes half of the piglets were in sternal position and after 112 minutes half of them showed coordinated movements. The body temperature decreased by 3.1 °C until 60 minutes after castration, especially small piglets reached critical temperature levels. 38 % of the piglets showed strong bleeding after castration. The healing of the wound was good according to 82 % of the farmers. 83 % of the farmers reported piglet losses, especially at the beginning of the anaesthesia period. The anaesthesia may be improved by using butorphanol in addition to the combination of ketamine and azaperone. The recovery of the piglets should be in a warm place without any risk of injury by obstacles or the sow. Increased bleeding can be controlled by using an emasculator. PMID:24297840

  16. Coal-water slurry spray characteristics of an electronically-controlled accumulator fuel injection system

    SciTech Connect

    Caton, J.A.; Payne, S.E.; Terracina, D.P.; Kihm, K.D.

    1993-12-31

    Experiments have been complete to characterize coal-water slurry sprays from a electronically-controlled accumulator fuel injection system of diesel engine. The sprays were injected into a pressurized chamber equipped with windows. High speed movies, fuel pressures and needle lifts were obtained as a function of time, orifice diameter, coal loading, gas density in the chamber, and accumulator fuel pressure. For the base conditions 50% (by mass) coal loading, 0.4 mm diameter nozzle hole, coal-water slurry pressure of 82 MPa (12,000 psi), and a chamber density of 25 kg/m{sup 3}, the break-up time was 0. 30 ms. An empirical correlation for both spray tip penetration and initial jet velocity was developed. For the conditions of this study, the spray tip penetration and initial jet velocity were 15% greater for coal-water slurry than for diesel fuel or water. Cone angles of the sprays were dependent on the operating conditions and fluid, as well as the time and locations of the measurement. The time-averaged cone angle for the base case conditions was 13.6{degree}. Results of this study and the correlation are specific to the tested coal-water slurry and are not general for other coal-water slurry fuels.

  17. Ant colony method to control variance reduction techniques in the Monte Carlo simulation of clinical electron linear accelerators

    NASA Astrophysics Data System (ADS)

    García-Pareja, S.; Vilches, M.; Lallena, A. M.

    2007-09-01

    The ant colony method is used to control the application of variance reduction techniques to the simulation of clinical electron linear accelerators of use in cancer therapy. In particular, splitting and Russian roulette, two standard variance reduction methods, are considered. The approach can be applied to any accelerator in a straightforward way and permits, in addition, to investigate the "hot" regions of the accelerator, an information which is basic to develop a source model for this therapy tool.

  18. A Design Methodology for Rapid Implementation of Active Control Systems Across Lean Direct Injection Combustor Platforms

    NASA Technical Reports Server (NTRS)

    Baumann, William T.; Saunders, William R.; Vandsburger, Uri; Saus, Joseph (Technical Monitor)

    2003-01-01

    The VACCG team is comprised of engineers at Virginia Tech who specialize in the subject areas of combustion physics, chemical kinetics, dynamics and controls, and signal processing. Currently, the team's work on this NRA research grant is designed to determine key factors that influence combustion control performance through a blend of theoretical and experimental investigations targeting design and demonstration of active control for three different combustors. To validiate the accuracy of conclusions about control effectiveness, a sequence of experimental verifications on increasingly complex lean, direct injection combustors is underway. During the work period January 1, 2002 through October 15, 2002, work has focused on two different laboratory-scale combustors that allow access for a wide variety of measurements. As the grant work proceeds, one key goal will be to obtain certain knowledge about a particular combustor process using a minimum of sophisticated measurements, due to the practical limitations of measurements on full-scale combustors. In the second year, results obtained in the first year will be validated on test combustors to be identified in the first quarter of that year. In the third year, it is proposed to validate the results at more realistic pressure and power levels by utilizing the facilities at the Glenn Research Center.

  19. Cavity control system advanced modeling and simulations for TESLA linear accelerator and free electron laser

    NASA Astrophysics Data System (ADS)

    Czarski, Tomasz; Romaniuk, Ryszard S.; Pozniak, Krzysztof T.; Simrock, Stefan

    2004-07-01

    The cavity control system for the TESLA -- TeV-Energy Superconducting Linear Accelerator project is initially introduced. The elementary analysis of the cavity resonator on RF (radio frequency) level and low level frequency with signal and power considerations is presented. For the field vector detection the digital signal processing is proposed. The electromechanical model concerning Lorentz force detuning is applied for analyzing the basic features of the system performance. For multiple cavities driven by one klystron the field vector sum control is considered. Simulink model implementation is developed to explore the feedback and feed-forward system operation and some experimental results for signals and power considerations are presented.

  20. Feedback control of torsion balance in measurement of gravitational constant G with angular acceleration method

    SciTech Connect

    Quan, Li-Di; Xue, Chao; Shao, Cheng-Gang; Yang, Shan-Qing; Tu, Liang-Cheng; Luo, Jun; Wang, Yong-Ji

    2014-01-15

    The performance of the feedback control system is of central importance in the measurement of the Newton's gravitational constant G with angular acceleration method. In this paper, a PID (Proportion-Integration-Differentiation) feedback loop is discussed in detail. Experimental results show that, with the feedback control activated, the twist angle of the torsion balance is limited to 7.3×10{sup −7} rad /√( Hz ) at the signal frequency of 2 mHz, which contributes a 0.4 ppm uncertainty to the G value.

  1. Late - Cycle Injection of Air/Oxygen - Enriched Air for Diesel Exhaust Emissions Control

    SciTech Connect

    Mather, Daniel

    2000-08-20

    Reduce the ''Engine Out'' particulates using the ''In Cylinder'' technique of late cycle auxiliary gas injection (AGI). Reduce the ''Engine Out'' NOx by combining AGI with optimization of fuel injection parameters. Maintain or Improve the Fuel Efficiency.

  2. Summary Report of Working Group 1: Laser-Plasma Acceleration

    SciTech Connect

    Geddes, C.G.R.; Clayton, C.; Lu, W.; Thomas, A.G.R.

    2010-06-01

    Advances in and physics of the acceleration of particles using underdense plasma structures driven by lasers were the topics of presentations and discussions in Working Group 1 of the 2010 Advanced Accelerator Concepts Workshop. Such accelerators have demonstrated gradients several orders beyond conventional machines, with quasi-monoenergetic beams at MeV-GeV energies, making them attractive candidates for next generation accelerators. Workshop discussions included advances in control over injection and laser propagation to further improve beam quality and stability, detailed diagnostics and physics models of the acceleration process, radiation generation as a source and diagnostic, and technological tools and upcoming facilities to extend the reach of laser-plasma accelerators.

  3. Data Processing Middleware in a High-Powered Neutral Beam Injection Control System

    NASA Astrophysics Data System (ADS)

    Sheng, Peng; Hu, Chundong; Song, Shihua; Liu, Zhimin; Zhao, Yuanzhe; Zhang, Xiaodan; Dou, Shaobin

    2013-06-01

    A set of data-processing middleware for a high-powered neutral beam injection (NBI) control system is presented in this paper. The middleware, based on TCP/IP and multi-threading technologies, focuses mainly on data processing and transmission. It separates the data processing and compression from data acquisition and storage. It provides universal transmitting interfaces for different software circumstances, such as WinCC, LabView and other measurement systems. The experimental data acquired on Windows, QNX and Linux platforms are processed by the middleware and sent to the monitoring applications. There are three middleware deployment models: serial processing, parallel processing and alternate serial processing. By using these models, the middleware solves real-time data-processing problems on heterogeneous environmental acquisition hardware with different operating systems and data applications.

  4. Fast optical frequency sweeping using voltage controlled oscillator driven single sideband modulation combined with injection locking.

    PubMed

    Wang, Jian; Chen, Dijun; Cai, Haiwen; Wei, Fang; Qu, Ronghui

    2015-03-23

    An ultrafast optical frequency sweeping technique for narrow linewidth lasers is reported. This technique exploits the large frequency modulation bandwidth of a wideband voltage controlled oscillator (VCO) and a high speed electro-optic dual parallel Mach-Zehnder modulator (DPMZM) which works on the state of carrier suppressed single sideband modulation(CS-SSB). Optical frequency sweeping of a narrow linewidth fiber laser with 3.85 GHz sweeping range and 80 GHz/μs tuning speed is demonstrated, which is an extremely high tuning speed for frequency sweeping of narrow linewidth lasers. In addition, injection locking technique is adopted to improve the sweeper's low optical power output and small side-mode suppression ratio (SMSR). PMID:25837048

  5. An advanced tracker design for pointing and control of space vehicles using the charge injection device

    NASA Technical Reports Server (NTRS)

    Jones, C.; Kollodge, J. C.

    1982-01-01

    The use of charge transfer devices (CTD) in pointing and control of space vehicles is examined, with emphasis on the use of charge injection devices (CID). The selection of CTD type and CID operation, including CID signal and noise analysis and signal improvement, are discussed. Star tracking operational advantages of the CTD are pointed out, and the tracking optical concept is discussed and graphically depicted. The position interpolation procedure and the effects of rate of stellar motion on position interpolation are considered, and error analysis is examined. Finally, the breadboard and test program are discussed in detail, coarse and fine acquisition, test for star, track pattern, test procedure and results. An overall accuracy performance of approximately 0.02 pixels or approximately 0.8 arcsec for the test equipment and tracker was obtained.

  6. State-of-the-Art developments in accelerator controls at the APS.

    SciTech Connect

    Lenkszus, F.

    1999-04-13

    The performance requirements of the Advanced Photon Source (APS) challenge the control system in a number of areas. This paper will review a few applications of advanced technology in the control and monitoring of the APS. The application of digital signal processors (DSPs) and techniques will be discussed, both from the perspective of a large distributed multiprocessor system and from that of embedded systems. In particular, two embedded applications will be highlighted, a beam position monitor processor and a DSP-based power supply controller. Fast data distribution is often a requirement. The application of a high-speed network based on reflective memory will also be discussed in the context of the APS global orbit feedback system. Timing systems provide opportunities to apply technologies such as high-speed logic and fiber optics. Examples of the use of these technologies will also be included. Finally, every modern accelerator control system of any size requires networking. Features of the APS accelerator controls network will be discussed.

  7. Insulin Injection

    MedlinePlus

    ... contraceptives (birth control pills, patches, rings, injections, or implants); niacin (Niacor, Niaspan, Slo-Niacin); octreotide (Sandostatin);oral ... cramps abnormal heartbeat large weight gain in a short period of time swelling of the arms, hands, ...

  8. Haloperidol Injection

    MedlinePlus

    ... emotions). Haloperidol injection is also used to control motor tics (uncontrollable need to repeat certain body movements) ... people who have Tourette's disorder (condition characterized by motor or verbal tics). Haloperidol is in a class ...

  9. Octreotide Injection

    MedlinePlus

    ... immediate-release injection is also used to control diarrhea and flushing caused by carcinoid tumors (slow-growing ... symptoms are severe or do not go away: diarrhea constipation pale, bulky, foul-smelling stools constantly feeling ...

  10. Experience in using workstations as hosts in an accelerator control environment

    SciTech Connect

    Abola, A.; Casella, R.; Clifford, T.; Hoff, L.; Katz, R.; Kennell, S.; Mandell, S.; McBreen, E.; Weygand, D.P.

    1987-03-01

    A new control system has been used for light ion acceleration at the Alternating Gradient Synchrotron (AGS). The control system uses Apollo workstations in the dual role of console hardware computer and controls system host. It has been found that having a powerful dedicated CPU with a demand paging virtual memory OS featuring strong interprocess communication, mapped memory shared files, shared code, and multi-window capabilities, allows us to provide an efficient operation environment in which users may view and manage several control processes simultaneously. The same features which make workstations good console computers also provide an outstanding platform for code development. The software for the system, consisting of about 30K lines of ''C'' code, was developed on schedule, ready for light ion commissioning. System development is continuing with work being done on applications programs.

  11. Control of focusing forces and emittances in plasma-based accelerators using near-hollow plasma channels

    SciTech Connect

    Schroeder, Carl; Esarey, Eric; Benedetti, Carlo; Leemans, Wim

    2013-08-06

    A near-hollow plasma channel, where the plasma density in the channel is much less than the plasma density in the walls, is proposed to provide independent control over the focusing and accelerating forces in a plasma accelerator. In this geometry the low density in the channel contributes to the focusing forces, while the accelerating fields are determined by the high density in the channel walls. The channel also provides guiding for intense laser pulses used for wakefield excitation. Both electron and positron beams can be accelerated in a nearly symmetric fashion. Near-hollow plasma channels can effectively mitigate emittance growth due to Coulomb scattering for high energy physics applications.

  12. Control of focusing forces and emittances in plasma-based accelerators using near-hollow plasma channels

    SciTech Connect

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

    2013-08-15

    A near-hollow plasma channel, where the plasma density in the channel is much less than the plasma density in the walls, is proposed to provide independent control over the focusing and accelerating forces in a plasma accelerator. In this geometry the low density in the channel contributes to the focusing forces, while the accelerating fields are determined by the high density in the channel walls. The channel also provides guiding for intense laser pulses used for wakefield excitation. Both electron and positron beams can be accelerated in a nearly symmetric fashion. Near-hollow plasma channels can effectively mitigate emittance growth due to Coulomb scattering for high-energy physics applications.

  13. Design and Flight Tests of an Adaptive Control System Employing Normal-Acceleration Command

    NASA Technical Reports Server (NTRS)

    McNeill, Water E.; McLean, John D.; Hegarty, Daniel M.; Heinle, Donovan R.

    1961-01-01

    An adaptive control system employing normal-acceleration command has been designed with the aid of an analog computer and has been flight tested. The design of the system was based on the concept of using a mathematical model in combination with a high gain and a limiter. The study was undertaken to investigate the application of a system of this type to the task of maintaining nearly constant dynamic longitudinal response of a piloted airplane over the flight envelope without relying on air data measurements for gain adjustment. The range of flight conditions investigated was between Mach numbers of 0.36 and 1.15 and altitudes of 10,000 and 40,000 feet. The final adaptive system configuration was derived from analog computer tests, in which the physical airplane control system and much of the control circuitry were included in the loop. The method employed to generate the feedback signals resulted in a model whose characteristics varied somewhat with changes in flight condition. Flight results showed that the system limited the variation in longitudinal natural frequency of the adaptive airplane to about half that of the basic airplane and that, for the subsonic cases, the damping ratio was maintained between 0.56 and 0.69. The system also automatically compensated for the transonic trim change. Objectionable features of the system were an exaggerated sensitivity of pitch attitude to gust disturbances, abnormally large pitch attitude response for a given pilot input at low speeds, and an initial delay in normal-acceleration response to pilot control at all flight conditions. The adaptive system chatter of +/-0.05 to +/-0.10 of elevon at about 9 cycles per second (resulting in a maximum airplane normal-acceleration response of from +/-0.025 g to +/- 0.035 g) was considered by the pilots to be mildly objectionable but tolerable.

  14. Nonlinear control of rotating stall and surge with axisymmetric bleed and air injection on axial flow compressors

    NASA Astrophysics Data System (ADS)

    Yeung, Chung-Hei (Simon)

    The study of compressor instabilities in gas turbine engines has received much attention in recent years. In particular, rotating stall and surge are major causes of problems ranging from component stress and lifespan reduction to engine explosion. In this thesis, modeling and control of rotating stall and surge using bleed valve and air injection is studied and validated on a low speed, single stage, axial compressor at Caltech. Bleed valve control of stall is achieved only when the compressor characteristic is actuated, due to the fast growth rate of the stall cell compared to the rate limit of the valve. Furthermore, experimental results show that the actuator rate requirement for stall control is reduced by a factor of fourteen via compressor characteristic actuation. Analytical expressions based on low order models (2--3 states) and a high fidelity simulation (37 states) tool are developed to estimate the minimum rate requirement of a bleed valve for control of stall. A comparison of the tools to experiments show a good qualitative agreement, with increasing quantitative accuracy as the complexity of the underlying model increases. Air injection control of stall and surge is also investigated. Simultaneous control of stall and surge is achieved using axisymmetric air injection. Three cases with different injector back pressure are studied. Surge control via binary air injection is achieved in all three cases. Simultaneous stall and surge control is achieved for two of the cases, but is not achieved for the lowest authority case. This is consistent with previous results for control of stall with axisymmetric air injection without a plenum attached. Non-axisymmetric air injection control of stall and surge is also studied. Three existing control algorithms found in literature are modeled and analyzed. A three-state model is obtained for each algorithm. For two cases, conditions for linear stability and bifurcation criticality on control of rotating stall are

  15. SO sub 2 and NO sub x control by combined dry injection of hydrated lime and sodium bicarbonate

    SciTech Connect

    Helfritch, D.J.; Botz, S.J. ); Beittel, R. ); Bergman, P.D. ); Toole-O'Neil, B. )

    1992-01-01

    The dry sorbent injection process for SO{sub 2} and NO{sub x} removal form coal-fired boiler flue gas consists of the use of low NO{sub x} burner technology for primary NO{sub x} reduction, injection of hydrated lime at economizer temperatures for primary capture of SO{sub 2} and injection of sodium bicarbonate at the air heater exit for additional SO{sub 2} and NO{sub x} removal. This concept has been separately tested at the .25 and 50 MM Btu/hour scales, utilizing test systems that duplicate the flue gas time-temperature profile found in full scale boiler systems. The results of these tests, including the effects of the sorbent injection on particle control devices, are described in this paper.

  16. FIELD TEST PROGRAM FOR EVALUATION OF SORBENT INJECTION FOR MERCURY CONTROL

    SciTech Connect

    Sharon Sjostrom

    2004-02-12

    The power industry in the U.S. is faced with meeting new regulations to reduce the emissions of mercury compounds from coal-fired plants. These regulations are directed at the existing fleet of nearly 1,100 boilers. These plants are relatively old with an average age of over 40 years. Although most of these units are capable of operating for many additional years, there is a desire to minimize large capital expenditures because of the reduced (and unknown) remaining life of the plant to amortize the project. Injecting a sorbent such as powdered activated carbon into the flue gas represents one of the simplest and most mature approaches to controlling mercury emissions from coal-fired boilers. The overall objective of this test program described in this quarterly report is to evaluate the capabilities of activated carbon injection at four plants with configurations that together represent 78% of the existing coal-fired generation plants. This technology was successfully evaluated in NETL's Phase I tests at scales up to 150 MW, on plants burning subbituminous and bituminous coals and with ESPs and fabric filters. The tests also identified issues that still need to be addressed, such as evaluating performance on other configurations, optimizing sorbent usage (costs), and gathering longer term operating data to address concerns about the impact of activated carbon on plant equipment and operations. The four sites identified for testing are Sunflower Electric's Holcomb Station, AmerenUE's Meramec Station, AEP's Conesville Station, and Ontario Power Generation's Nanticoke Station. This is the first quarterly report for this project. This report includes an overview of the plans for the project. Field testing is scheduled to begin next quarter. In general, quarterly reports will be used to provide project overviews, project status, and technology transfer information. Topical reports will be prepared to present detailed technical information.

  17. The role of harm reduction in controlling HIV among injecting drug users

    PubMed Central

    Wodak, Alex; McLeod, Leah

    2012-01-01

    Injecting drug users (IDU) now account for one in 10 new HIV infections world wide. Yet it has been known since the early 1990s that HIV among IDU can be effectively, safely and cost-effectively controlled by the early and vigorous implementation of a comprehensive package of strategies known as ’harm reduction’. This concept means that decreasing drug-related harms is accorded an even higher priority than reduction of drug consumption. Strategies required involve: explicit and peer-based education about the risk of HIV from sharing injecting equipment; needle syringe programmes; drug treatment (including especially opiate substitution treatment) and community development. Many countries experiencing or threatened by an HIV epidemic among IDU have now adopted harm reduction but often implementation has been too little and too late. Although coverage is slowly improving in many countries, HIV is still spreading faster among IDU than harm reduction programmes while coverage in correctional centres lags far behind community settings. The scientific debate about harm reduction is now over. National and international support for harm reduction is growing while almost all the major UN organizations responsible for drug policy now support harm reduction. Only a small number of countries, led by the USA, are still vehemently opposed to harm reduction. Excessive reliance on drug law enforcement remains the major barrier to increased adoption of harm reduction. Sometimes zealous drug law enforcement undermines harm reduction. A more balanced approach to drug law enforcement is required with illicit drug use recognized primarily as a health and social problem. PMID:18641473

  18. Evolution of pulse shapes during compressor scans in a CPA system and control of electron acceleration in plasmas

    SciTech Connect

    Toth, Csaba; de Groot, Joeri; van Tilborg, Jeroen; Geddes, Cameron G.R.; Faure, Jerome; Catravas, Palma; Schroeder, Carl; Shadwick, B.A.; Esarey, Eric; Leemans, Wim

    2002-05-12

    The skewness of the envelope function of 20 - 100 femtosecond Ti:sapphire laser pulses has been controlled by appropriate choice of the higher order special phase coefficients, and used for optimization of a plasma wakefield electron accelerator.

  19. A survey of the practice and management of radiotherapy linear accelerator quality control in the UK

    PubMed Central

    Palmer, A; Kearton, J; Hayman, O

    2012-01-01

    Objectives The objective of this study was to determine current radiotherapy linear accelerator quality control (QC) practice in the UK, as a comparative benchmark and indicator of development needs, and to raise awareness of QC as a key performance indicator. Methods All UK radiotherapy centres were invited to complete an online questionnaire regarding their local QC processes, and submit their QC schedules. The range of QC tests, frequency of measurements and acceptable tolerances in use across the UK were analysed, and consensus and range statistics determined. Results 72% of the UK's 62 radiotherapy centres completed the questionnaire and 40% provided their QC schedules. 60 separate QC tests were identified from the returned schedules. There was a large variation in the total time devoted to QC between centres: interquartile range from 13 to 26 h per linear accelerator per month. There has been a move from weekly to monthly testing of output calibration in the last decade, with reliance on daily constancy testing equipment. 33% of centres thought their schedules were in need of an update and only 30% used risk-assessment approaches to determine local QC schedule content. Less than 30% of centres regularly complete all planned QC tests each month, although 96% achieve over 80% of tests. Conclusions A comprehensive “snapshot” of linear accelerator QC testing practice in the UK has been collated, which demonstrates reasonable agreement between centres in their stated QC test frequencies. However, intelligent design of QC schedules and management is necessary to ensure efficiency and appropriateness. PMID:22674707

  20. Duct injection for SO{sub 2} control, Design Handbook, Volume 1, Process design and engineering guidelines

    SciTech Connect

    1995-09-01

    PETC developed a comprehensive program of coal-related, acid-rain research and development with a major activity area centering on flue gas cleanup and control of SO{sub 2} emissions. Particular emphasis was placed on the retrofit measures for older coal-fired power plants which predate the 1971 New Source Performance Standards. Candidate emission control technologies fall into three categories, depending upon their point of application along the fuel path (i.e., pre, during, or post combustion). The post-combustion, in-duct injection of a calcium-based chemical reagent seemed promising. Preliminary studies showed that reagent injection between the existing air heater and electrostatic precipitator (ESP) could remove between 50-60% of the SO{sub 2} and produce an environmentally safe, dry, solid waste that is easily disposed. Although SO{sub 2} removal efficiencies were less, the estimated capital costs for duct injection technology were low making the economics of duct injection systems seem favorable when compared to conventional wet slurry scrubbers under certain circumstances. With the promulgation of the Clean Air Act Amendments of 1990 came more incentive for the development of low capital cost flue gas desulfurization (FGD) processes. A number of technical problems had to be resolved, however, before duct injection technology could be brought to a state of commercial readiness. The Duct Injection Technology Development Program was launched as a comprehensive, four-year research effort undertaken by PETC to develop this new technology. Completed in 1992, this Duct Injection Design Handbook and the three-dimensional predictive mathematical model constitute two primary end products from this development program. The aim of this design handbook and the accompanying math model is to provide utility personnel with sufficient information to evaluate duct injection technology against competing SO{sub 2} emissions reduction strategies for an existing plant.

  1. Filter-based control of particulate matter from a lean gasoline direct injection engine

    SciTech Connect

    Parks, II, James E; Lewis Sr, Samuel Arthur; DeBusk, Melanie Moses; Prikhodko, Vitaly Y; Storey, John Morse

    2016-01-01

    New regulations requiring increases in vehicle fuel economy are challenging automotive manufacturers to identify fuel-efficient engines for future vehicles. Lean gasoline direct injection (GDI) engines offer significant increases in fuel efficiency over the more common stoichiometric GDI engines already in the marketplace. However, particulate matter (PM) emissions from lean GDI engines, particularly during stratified combustion modes, are problematic for lean GDI technology to meet U.S. Environmental Protection Agency Tier 3 and other future emission regulations. As such, the control of lean GDI PM with wall-flow filters, referred to as gasoline particulate filter (GPF) technology, is of interest. Since lean GDI PM chemistry and morphology differ from diesel PM (where more filtration experience exists), the functionality of GPFs needs to be studied to determine the operating conditions suitable for efficient PM removal. In addition, lean GDI engine exhaust temperatures are generally higher than diesel engines which results in more continuous regeneration of the GPF and less presence of the soot cake layer common to diesel particulate filters. Since the soot layer improves filtration efficiency, this distinction is important to consider. Research on the emission control of PM from a lean GDI engine with a GPF was conducted on an engine dynamometer. PM, after dilution, was characterized with membrane filters, organic vs. elemental carbon characterization, and size distribution techniques at various steady state engine speed and load points. The engine was operated in three primary combustion modes: stoichiometric, lean homogeneous, and lean stratified. In addition, rich combustion was utilized to simulate PM from engine operation during active regeneration of lean NOx control technologies. High (>95%) PM filtration efficiencies were observed over a wide range of conditions; however, some PM was observed to slip through the GPF at high speed and load conditions. The

  2. Indian primacy procedures handbook for the public water system supervision (PWSS) program and the underground injection control (UIC) program

    SciTech Connect

    Not Available

    1993-03-01

    The handbook defines primacy, the responsibilities of primacy, primacy's advantages and limitations, and how to seek primacy. Primacy is a provision in the 1986 Amendments to the Safe Drinking Water Act (SDWA). It allows Indian Tribes the opportunity to assume principal responsibility in the enforcement of public drinking water and/or underground injection control (UIC) regulations within the Indian Tribe's jurisdiction. To attain primacy a Tribe must have drinking water and underground injection control regulations which are at least as strict as EPA regulations, and must have an independent agency or organization within the Tribal government that has the power to enforce its regulations.

  3. Laser Plasma Accelerators

    NASA Astrophysics Data System (ADS)

    Malka, Victor

    The continuing development of powerful laser systems has permitted to extend the interaction of laser beams with matter far into the relativistic domain, and to demonstrate new approaches for producing energetic particle beams. The extremely large electric fields, with amplitudes exceeding the TV/m level, that are produced in plasma medium are of relevance particle acceleration. Since the value of this longitudinal electric field, 10,000 times larger than those produced in conventional radio-frequency cavities, plasma accelerators appear to be very promising for the development of compact accelerators. The incredible progresses in the understanding of laser plasma interaction physic, allows an excellent control of electron injection and acceleration. Thanks to these recent achievements, laser plasma accelerators deliver today high quality beams of energetic radiation and particles. These beams have a number of interesting properties such as shortness, brightness and spatial quality, and could lend themselves to applications in many fields, including medicine, radio-biology, chemistry, physics and material science,security (material inspection), and of course in accelerator science.

  4. Extended analytical formulas for the perturbed Keplerian motion under a constant control acceleration

    NASA Astrophysics Data System (ADS)

    Zuiani, Federico; Vasile, Massimiliano

    2015-03-01

    This paper presents a set of analytical formulae for the perturbed Keplerian motion of a spacecraft under the effect of a constant control acceleration. The proposed set of formulae can treat control accelerations that are fixed in either a rotating or inertial reference frame. Moreover, the contribution of the zonal harmonic is included in the analytical formulae. It will be shown that the proposed analytical theory allows for the fast computation of long, multi-revolution spirals while maintaining good accuracy. The combined effect of different perturbations and of the shadow regions due to solar eclipse is also included. Furthermore, a simplified control parameterisation is introduced to optimise thrusting patterns with two thrust arcs and two cost arcs per revolution. This simple parameterisation is shown to ensure enough flexibility to describe complex low thrust spirals. The accuracy and speed of the proposed analytical formulae are compared against a full numerical integration with different integration schemes. An averaging technique is then proposed as an application of the analytical formulae. Finally, the paper presents an example of design of an optimal low-thrust spiral to transfer a spacecraft from an elliptical to a circular orbit around the Earth.

  5. Distribution of computer functionality for accelerator control at the Brookhaven AGS

    SciTech Connect

    Stevens, A.; Clifford, T.; Frankel, R.

    1985-01-01

    A set of physical and functional system components and their interconnection protocols have been established for all controls work at the AGS. Portions of these designs were tested as part of enhanced operation of the AGS as a source of polarized protons and additional segments will be implemented during the continuing construction efforts which are adding heavy ion capability to our facility. Included in our efforts are the following computer and control system elements: a broad band local area network, which embodies MODEMS; transmission systems and branch interface units; a hierarchical layer, which performs certain data base and watchdog/alarm functions; a group of work station processors (Apollo's) which perform the function of traditional minicomputer host(s) and a layer, which provides both real time control and standardization functions for accelerator devices and instrumentation. Data base and other accelerator functionality is assigned to the most correct level within our network for both real time performance, long-term utility, and orderly growth.

  6. Distribution of computer functionality for accelerator control at the Brookhaven AGS

    SciTech Connect

    Stevens, A.; Clifford, T.; Frankel, R.

    1985-10-01

    A set of physical and functional system components and their interconnection protocols have been established for all controls work at the AGS. Portions of these designs were tested as part of enhanced operation of the AGS as a source of polarized protons and additional segments will be implemented during the continuing construction efforts which are adding heavy ion capability to our facility. Included in our efforts are the following computer and control system elements: a broad band local area network, which embodies MODEMS; transmission systems and branch interface units; a hierarchical layer, which performs certain data base and watchdog/alarm functions; a group of work station processors (Apollo's) which perform the function of traditional minicomputer host(s) and a layer, which provides both real time control and standardization functions for accelerator devices and instrumentation. Data base and other accelerator functionality is assigned to the most correct level within our network for both real time performance, long-term utility, and orderly growth.

  7. Control of target-normal-sheath-accelerated protons from a guiding cone

    SciTech Connect

    Zou, D. B.; Zhuo, H. B.; Yang, X. H.; Yu, T. P.; Shao, F. Q.; Pukhov, A.

    2015-06-15

    It is demonstrated through particle-in-cell simulations that target-normal-sheath-accelerated protons can be well controlled by using a guiding cone. Compared to a conventional planar target, both the collimation and number density of proton beams are substantially improved, giving a high-quality proton beam which maintained for a longer distance without degradation. The effect is attributed to the radial electric field resulting from the charge due to the hot target electrons propagating along the cone surface. This electric field can effectively suppress the spatial spread of the protons after the expansion of the hot electrons.

  8. Data acquisition, storage and control architecture for the SuperNova Acceleration Probe

    SciTech Connect

    Prosser, Alan; Cardoso, Guilherme; Chramowicz, John; Marriner, John; Rivera, Ryan; Turqueti, Marcos; /Fermilab

    2007-05-01

    The SuperNova Acceleration Probe (SNAP) instrument is being designed to collect image and spectroscopic data for the study of dark energy in the universe. In this paper, we describe a distributed architecture for the data acquisition system which interfaces to visible light and infrared imaging detectors. The architecture includes the use of NAND flash memory for the storage of exposures in a file system. Also described is an FPGA-based lossless data compression algorithm with a configurable pre-scaler based on a novel square root data compression method to improve compression performance. The required interactions of the distributed elements with an instrument control unit will be described as well.

  9. ACCELERATED TESTING OF NEUTRON-ABSORBING ALLOYS FOR NUCLEAR CRITICALITY CONTROL

    SciTech Connect

    Ronald E. Mizia

    2011-10-01

    The US Department of Energy requires nuclear criticality control materials be used for storage of highly enriched spent nuclear fuel used in government programs and the storage of commercial spent nuclear fuel at the proposed High-Level Nuclear Waste Geological Repository located at Yucca Mountain, Nevada. Two different metallic alloys (Ni-Cr-Mo-Gd and borated stainless steel) have been chosen for this service. An accelerated corrosion test program to validate these materials for this application is described and a performance comparison is made.

  10. Optimization and control of two-component radially self-accelerating beams

    SciTech Connect

    Vetter, Christian; Eichelkraut, Toni; Ornigotti, Marco; Szameit, Alexander

    2015-11-23

    We report on the properties of radially self-accelerating intensity distributions consisting of two components in the angular frequency domain. We show how this subset of solutions, in literature also known as helicon beams, possesses peculiar characteristics that enable a better control over its properties. In this work, we present a step-by-step optimization procedure to achieve the best possible intensity contrast, a distinct rotation rate and long propagation lengths. All points are discussed on a theoretical basis and are experimentally verified.

  11. Injection molding of iPP samples in controlled conditions and resulting morphology

    NASA Astrophysics Data System (ADS)

    Sessa, Nino; De Santis, Felice; Pantani, Roberto

    2015-12-01

    Injection molded parts are driven down in size and weight especially for electronic applications. In this work, an investigation was carried out on the process of injection molding of thin iPP samples and on the morphology of these parts. Melt flow in the mold cavity was analyzed and described with a mathematical model. Influence of mold temperature and injection pressure was analyzed. Samples orientation was studied using optical microscopy.

  12. Injection molding of iPP samples in controlled conditions and resulting morphology

    SciTech Connect

    Sessa, Nino De Santis, Felice Pantani, Roberto

    2015-12-17

    Injection molded parts are driven down in size and weight especially for electronic applications. In this work, an investigation was carried out on the process of injection molding of thin iPP samples and on the morphology of these parts. Melt flow in the mold cavity was analyzed and described with a mathematical model. Influence of mold temperature and injection pressure was analyzed. Samples orientation was studied using optical microscopy.

  13. Subacromial impingement syndrome and pain: protocol for a randomised controlled trial of exercise and corticosteroid injection (the SUPPORT trial)

    PubMed Central

    2014-01-01

    Background Subacromial impingement syndrome is the most frequent cause of shoulder problems which themselves affect 1 in 3 adults. Management commonly includes exercise and corticosteroid injection. However, the few existing trials of exercise or corticosteroid injection for subacromial impingement syndrome are mostly small, of poor quality, and focus only on short-term results. Exercise packages tend to be standardised rather than individualised and progressed. There has been much recent interest in improving outcome from corticosteroid injections by using musculoskeletal ultrasound to guide injections. However, there are no high-quality trials comparing ultrasound-guided and blind corticosteroid injection in subacromial impingement syndrome. This trial will investigate how to optimise the outcome of subacromial impingement syndrome from exercise (standardised advice and information leaflet versus physiotherapist-led exercise) and from subacromial corticosteroid injection (blind versus ultrasound-guided), and provide long-term follow-up data on clinical and cost-effectiveness. Methods/Design The study design is a 2x2 factorial randomised controlled trial. 252 adults with subacromial impingement syndrome will be recruited from two musculoskeletal Clinical Assessment and Treatment Services at the primary-secondary care interface in Staffordshire, UK. Participants will be randomised on a 1:1:1:1 basis to one of four treatment groups: (1) ultrasound-guided subacromial corticosteroid injection and a physiotherapist-led exercise programme, (2) ultrasound-guided subacromial corticosteroid injection and an advice and exercise leaflet, (3) blind subacromial corticosteroid injection and a physiotherapist-led exercise programme, or (4) blind subacromial corticosteroid injection and an advice and exercise leaflet. The primary intention-to-treat analysis will be the mean differences in Shoulder Pain and Disability Index (SPADI) scores at 6 weeks for the comparison between

  14. CO2 migration in the vadose zone: experimental and numerical modelling of controlled gas injection

    NASA Astrophysics Data System (ADS)

    gasparini, andrea; credoz, anthony; grandia, fidel; garcia, david angel; bruno, jordi

    2014-05-01

    The mobility of CO2 in the vadose zone and its subsequent transfer to the atmosphere is a matter of concern in the risk assessment of the geological storage of CO2. In this study the experimental and modelling results of controlled CO2 injection are reported to better understanding of the physical processes affecting CO2 and transport in the vadose zone. CO2 was injected through 16 micro-injectors during 49 days of experiments in a 35 m3 experimental unit filled with sandy material, in the PISCO2 facilities at the ES.CO2 centre in Ponferrada (North Spain). Surface CO2 flux were monitored and mapped periodically to assess the evolution of CO2 migration through the soil and to the atmosphere. Numerical simulations were run to reproduce the experimental results, using TOUGH2 code with EOS7CA research module considering two phases (gas and liquid) and three components (H2O, CO2, air). Five numerical models were developed following step by step the injection procedure done at PISCO2. The reference case (Model A) simulates the injection into a homogeneous soil(homogeneous distribution of permeability and porosity in the near-surface area, 0.8 to 0.3 m deep from the atmosphere). In another model (Model B), four additional soil layers with four specific permeabilities and porosities were included to predict the effect of differential compaction on soil. To account for the effect of higher soil temperature, an isothermal simulation called Model C was also performed. Finally, the assessment of the rainfall effects (soil water saturation) on CO2 emission on surface was performed in models called Model D and E. The combined experimental and modelling approach shows that CO2 leakage in the vadose zone quickly comes out through preferential migration pathways and spots with the ranges of fluxes in the ground/surface interface from 2.5 to 600 g·m-2·day-1. This gas channelling is mainly related to soil compaction and climatic perturbation. This has significant implications to

  15. Controlling outbreaks of the coral-eating crown-of-thorns starfish using a single injection of common household vinegar

    NASA Astrophysics Data System (ADS)

    Boström-Einarsson, Lisa; Rivera-Posada, Jairo

    2016-03-01

    Outbreaks of the destructive coral-eating crown-of-thorns starfish, Acanthaster planci, present a considerable threat to coral reefs worldwide, and mitigating their impact has proven challenging. The most effective methods to control A. planci require injecting individual starfish with lethal chemicals. While some of these are highly effective, their administration often requires permits, training and access to specialised equipment. We aimed to identify a widely available and highly efficient alternative. We discovered that common household vinegar is lethal to A. planci individuals when injected at the base of one their arms. A single injection of 25 ml vinegar induced functional mortality in <24 h and 100 % mortality in <48 h. These results demonstrate that vinegar is an effective alternative to currently used chemicals. Vinegar is a viable alternative in the toolkit of methods that can control and eradicate local outbreaks of COTS on coral reefs.

  16. Future directions in controlling the LAMPF-PSR Accelerator Complex at Los Alamos National Laboratory

    SciTech Connect

    Stuewe, R.; Schaller, S.; Bjorklund, E.; Burns, M.; Callaway, T.; Carr, G.; Cohen, S.; Kubicek, D.; Harrington, M.; Poore, R.; Schultz, D.

    1991-01-01

    Four interrelated projects are underway whose purpose is to migrate the LAMPF-PSR Accelerator Complex control systems to a system with a common set of hardware and software components. Project goals address problems in performance, maintenance and growth potential. Front-end hardware, operator interface hardware and software, computer systems, network systems and data system software are being simultaneously upgraded as part of these efforts. The efforts are being coordinated to provide for a smooth and timely migration to a client-sever model-based data acquisition and control system. An increased use of the distributed intelligence at both the front-end and operator interface is a key element of the projects. 2 refs., 2 figs.

  17. Controlling device for a fuel-quantity adjusting member of a fuel injection pump

    SciTech Connect

    Eheim, F.; Hofer, G.; Konrath, K.; Straubel, M.

    1987-11-03

    This patent describes a controlling device for a fuel-quantity adjustment element of a fuel injection pump including an adjusting lever pivotable around a shaft. The adjusting lever is coupled with a fuel-quantity adjusting element, a drag lever pivotable around the shaft of the adjusting lever. The drag lever communicates with the adjusting lever by way of a coupling element. An adjustable governor spring assembly is arranged to act on the drag lever, a stop for stopping the drag lever, further including a device for generating rpm-dependent force transmittable to the drag lever by means of an actuating element thereof and counter to the governor spring assembly, whereby the drag lever and the adjusting lever are coupled for movement together at least at the end of each relative movement effected by the actuating element. The actuating element acts directly upon the drag lever and the adjusting lever during deflection by way of a predetermined relative adjustment distance between the drag lever and the adjusting lever for adjustment by the actuating element, at least one spring arranged between the adjusting lever and a fixed support. At least one spring acts on the adjusting lever to force the adjusting lever into contact with an adjustable stop which is adjustable in dependence from the operating parameters of the combustion engine.

  18. Field evaluation of natural gas and dry sorbent injection for MWC emissions control

    SciTech Connect

    Wohadlo, S; Abbasi, H; Cygan, D

    1993-10-01

    The Institute of Gas Technology (IGT), in cooperation with the Olmsted Waste-to-Energy Facility (OWEF) and with subcontracted engineering services from the Energy and Environmental Research Corporation (EER), has completed the detailed engineering and preparation of construction specifications for an Emissions Reduction Testing System (ERTS). The ERTS has been designed for retrofit to one of two 100-ton/day municipal waste combustors at the OWEF, located in Rochester, Minnesota. The purpose of the retrofit is to conduct a field evaluation of a combined natural gas and sorbent injection process (IGT`s METHANE de-TOX{sup SM}, IGT Patent No. 5,105,747) for reducing the emissions of oxides of nitrogen (NO{sub x}), hydrochloric acid (HCI), oxides of sulfur (SO{sub x}), carbon monoxide (CO), total hydrocarbons (THC), and chlorinated hydrocarbons (dioxin/furans). In addition, the design includes modifications for the control of heavy metals (HM). Development of the process should allow the waste-to-energy industry to meet the Federal New Source Performance Standards for these pollutants at significantly lower costs when compared to existing technology of Thermal deNO{sub x} combined with spray dryer scrubber/fabric filters. Additionally, the process should reduce boiler corrosion and increase both the thermal and power production efficiency of the facility.

  19. Plasmon Injection to Compensate and Control Losses in Negative Index Metamaterials.

    PubMed

    Sadatgol, Mehdi; Özdemir, Şahin K; Yang, Lan; Güney, Durdu Ö

    2015-07-17

    Metamaterials have introduced a whole new world of unusual materials with functionalities that cannot be attained in naturally occurring material systems by mimicking and controlling the natural phenomena at subwavelength scales. However, the inherent absorption losses pose a fundamental challenge to the most fascinating applications of metamaterials. Based on a novel plasmon injection (PI or Π) scheme, we propose a coherent optical amplification technique to compensate losses in metamaterials. Although the proof of concept device here operates under normal incidence only, our proposed scheme can be generalized to an arbitrary form of incident waves. The Π scheme is fundamentally different from major optical amplification schemes. It does not require a gain medium, interaction with phonons, or any nonlinear medium. The Π scheme allows for loss-free metamaterials. It is ideally suited for mitigating losses in metamaterials operating in the visible spectrum and is scalable to other optical frequencies. These findings open the possibility of reviving the early dreams of making "magical" metamaterials from scratch. PMID:26230802

  20. A nanocomposite ultraviolet photodetector based on interfacial trap-controlled charge injection.

    PubMed

    Guo, Fawen; Yang, Bin; Yuan, Yongbo; Xiao, Zhengguo; Dong, Qingfeng; Bi, Yu; Huang, Jinsong

    2012-12-01

    Ultraviolet photodetectors have applications in fields such as medicine, communications and defence, and are typically made from single-crystalline silicon, silicon carbide or gallium nitride p-n junction photodiodes. However, such inorganic photodetectors are unsuitable for certain applications because of their high cost and low responsivity (<0.2 A W(-1)). Solution-processed photodetectors based on organic materials and/or nanomaterials could be significantly cheaper to manufacture, but their performance so far has been limited. Here, we show that a solution-processed ultraviolet photodetector with a nanocomposite active layer composed of ZnO nanoparticles blended with semiconducting polymers can significantly outperform inorganic photodetectors. As a result of interfacial trap-controlled charge injection, the photodetector transitions from a photodiode with a rectifying Schottky contact in the dark, to a photoconductor with an ohmic contact under illumination, and therefore combines the low dark current of a photodiode and the high responsivity of a photoconductor (∼721-1,001 A W(-1)). Under a bias of <10 V, our device provides a detectivity of 3.4 × 10(15) Jones at 360 nm at room temperature, which is two to three orders of magnitude higher than that of existing inorganic semiconductor ultraviolet photodetectors. PMID:23142945

  1. A nanocomposite ultraviolet photodetector based on interfacial trap-controlled charge injection

    NASA Astrophysics Data System (ADS)

    Guo, Fawen; Yang, Bin; Yuan, Yongbo; Xiao, Zhengguo; Dong, Qingfeng; Bi, Yu; Huang, Jinsong

    2012-12-01

    Ultraviolet photodetectors have applications in fields such as medicine, communications and defence, and are typically made from single-crystalline silicon, silicon carbide or gallium nitride p-n junction photodiodes. However, such inorganic photodetectors are unsuitable for certain applications because of their high cost and low responsivity (<0.2 A W-1). Solution-processed photodetectors based on organic materials and/or nanomaterials could be significantly cheaper to manufacture, but their performance so far has been limited. Here, we show that a solution-processed ultraviolet photodetector with a nanocomposite active layer composed of ZnO nanoparticles blended with semiconducting polymers can significantly outperform inorganic photodetectors. As a result of interfacial trap-controlled charge injection, the photodetector transitions from a photodiode with a rectifying Schottky contact in the dark, to a photoconductor with an ohmic contact under illumination, and therefore combines the low dark current of a photodiode and the high responsivity of a photoconductor (~721-1,001 A W-1). Under a bias of <10 V, our device provides a detectivity of 3.4 × 1015 Jones at 360 nm at room temperature, which is two to three orders of magnitude higher than that of existing inorganic semiconductor ultraviolet photodetectors.

  2. A repertoire of peptide tags for controlled drug release from injectable noncovalent hydrogel.

    PubMed

    Wieduwild, Robert; Lin, Weilin; Boden, Annett; Kretschmer, Karsten; Zhang, Yixin

    2014-06-01

    A repertoire of conjugable tags for controlling the release of drugs from biomaterials is highly interesting for the development of combinatorial drug administration techniques. This paper describes such a system of 11 peptide tags derived from our previous work on a physical hydrogel system cross-linked through peptide-heparin interactions. The release kinetics of the tags correlate well with their affinity to heparin and obey Fick's second law of diffusion, with the exception of the ATIII peptide, which displays a stable release profile close to a zero-order reaction. A system for release experiments over seven months was built, using the hydrogel matrix as a barrier between the reservoirs of tagged compounds and supernatant. The gel matrix can be injected without affecting the releasing properties. A tagged cyclosporin A derivative was also tested, and its release was monitored by measuring its biological activity. This work represents a design of biomaterials with an integral system of drug delivery, where both the assembly process of the matrix and affinity capture/release of tagged compounds are based on the noncovalent interaction of heparin with one class of peptides. PMID:24825401

  3. Advanced in-duct sorbent injection for SO{sub 2} control. Final technical report

    SciTech Connect

    Stouffer, M.R.; Withium, J.A.; Rosenhoover, W.A.; Maskew, J.T.

    1994-12-01

    The objective of this research project was to develop a second generation duct sorbent injection technology as a cost-effective compliance option for the 1990 Clean Air Act Amendments. Research and development work was focused on the Advanced Coolside process, which showed the potential for exceeding the original performance targets of 90% SO{sub 2} removal and 60% sorbent utilization. Process development was conducted in a 1000 acfm pilot plant. The pilot plant testing showed that the Advanced Coolside process can achieve 90% SO{sub 2} removal at sorbent utilizations up to 75%. The testing also showed that the process has the potential to achieve very high removal efficiency (90 to >99%). By conducting conceptual process design and economic evaluations periodically during the project, development work was focused on process design improvements which substantially lowered process capital and operating costs, A final process economic study projects capital costs less than one half of those for limestone forced oxidation wet FGD. Projected total SO{sub 2} control cost is about 25% lower than wet FGD for a 260 MWe plant burning a 2.5% sulfur coal. A waste management study showed the acceptability of landfill disposal; it also identified a potential avenue for by-product utilization which should be further investigated. Based on the pilot plant performance and on the above economic projections, future work to scale up the Advanced Coolside process is recommended.

  4. Plasmon Injection to Compensate and Control Losses in Negative Index Metamaterials

    NASA Astrophysics Data System (ADS)

    Sadatgol, Mehdi; Ã-zdemir, Şahin K.; Yang, Lan; Güney, Durdu Ã.-.

    2015-07-01

    Metamaterials have introduced a whole new world of unusual materials with functionalities that cannot be attained in naturally occurring material systems by mimicking and controlling the natural phenomena at subwavelength scales. However, the inherent absorption losses pose a fundamental challenge to the most fascinating applications of metamaterials. Based on a novel plasmon injection (PI or Π ) scheme, we propose a coherent optical amplification technique to compensate losses in metamaterials. Although the proof of concept device here operates under normal incidence only, our proposed scheme can be generalized to an arbitrary form of incident waves. The Π scheme is fundamentally different from major optical amplification schemes. It does not require a gain medium, interaction with phonons, or any nonlinear medium. The Π scheme allows for loss-free metamaterials. It is ideally suited for mitigating losses in metamaterials operating in the visible spectrum and is scalable to other optical frequencies. These findings open the possibility of reviving the early dreams of making "magical" metamaterials from scratch.

  5. First demonstration and performance of an injection locked continuous wave magnetron to phase control a superconducting cavity

    SciTech Connect

    A.C. Dexter, G. Burt, R.G. Carter, I. Tahir, H. Wang, K. Davis, R. Rimmer

    2011-03-01

    The applications of magnetrons to high power proton and cw electron linacs are discussed. An experiment is described where a 2.45 GHz magnetron has been used to drive a single cell superconducting cavity. With the magnetron injection locked, a modest phase control accuracy of 0.95° rms has been demonstrated. Factors limiting performance have been identified.

  6. Intelligent emissions controller for substance injection in the post-primary combustion zone of fossil-fired boilers

    DOEpatents

    Reifman, Jaques; Feldman, Earl E.; Wei, Thomas Y. C.; Glickert, Roger W.

    2003-01-01

    The control of emissions from fossil-fired boilers wherein an injection of substances above the primary combustion zone employs multi-layer feedforward artificial neural networks for modeling static nonlinear relationships between the distribution of injected substances into the upper region of the furnace and the emissions exiting the furnace. Multivariable nonlinear constrained optimization algorithms use the mathematical expressions from the artificial neural networks to provide the optimal substance distribution that minimizes emission levels for a given total substance injection rate. Based upon the optimal operating conditions from the optimization algorithms, the incremental substance cost per unit of emissions reduction, and the open-market price per unit of emissions reduction, the intelligent emissions controller allows for the determination of whether it is more cost-effective to achieve additional increments in emission reduction through the injection of additional substance or through the purchase of emission credits on the open market. This is of particular interest to fossil-fired electrical power plant operators. The intelligent emission controller is particularly adapted for determining the economical control of such pollutants as oxides of nitrogen (NO.sub.x) and carbon monoxide (CO) emitted by fossil-fired boilers by the selective introduction of multiple inputs of substances (such as natural gas, ammonia, oil, water-oil emulsion, coal-water slurry and/or urea, and combinations of these substances) above the primary combustion zone of fossil-fired boilers.

  7. Tests of ionospheric control of young injection events identified from magnetometer observations at Saturn

    NASA Astrophysics Data System (ADS)

    Kivelson, M.; Jia, X.

    2015-12-01

    Kennelly et al. (2013) reported that young plasma injection events observed in Saturn's nightside magnetosphere and identified from plasma wave signatures are modulated at the period associated with the winter hemisphere. In a system unstable to interchange, radial motion of flux tubes is constrained by the "line-tying" effect of high ionospheric conductance (Southwood and Kivelson, 1989). Slippage of a flux tube would then occur initially in the hemisphere in which the ionospheric conductance is lowest. Saturn's ionospheric conductances vary not only with season, but also with rotation phase because of the presence of a pattern of rotating field-aligned currents that drive "planetary period oscillations" (Jia and Kivelson, 2012). The conductance should minimize near the center of the downward current region and, at this rotation phase in the winter hemisphere, the growth rate of the instability would be largest, accounting for control by the northern period. With motion starting in the winter hemisphere, the flux tube would develop a tilt of predictable sense and the initial inward motion of the interchanging flux tube would occur at a specific rotation phase of the winter ionosphere. For a subset of the Kennelly events, we found that the tilt and phase are consistent with expectations based on the control of displacement by ionospheric conductance. Many additional young interchange events have been identified by K. K. Khurana [personal communication, 2015] whom we thank for making the list available. We examine this more extensive set of events and use them to investigate the proposed mechanism more fully. __________ Jia, X., and M. G. Kivelson (2012), J. Geophys. Res., 117, A11219. Kennelly, T. J., J. S. Leisner, G. B. Hospodarsky, and D. A. Gurnett (2013), J. Geophys. Res. Space Physics, 118, 832-838. Kivelson, M., and X. Jia (2014), , AGU Fall meeting, 2014, SM51E-4295. Southwood, D. J., and M. G. Kivelson (1989), J. Geophys. Res., 94, 299-308.

  8. Plastic Injection Quality Controlling Using the Lean Six Sigma and FMEA Method

    NASA Astrophysics Data System (ADS)

    Mansur, A.; Mu'alim; Sunaryo

    2016-01-01

    PT. Yogya Presisi Teknikatama Industri (PT. YPTI) is a mold, precision part, and plastic injection maker company. One of the obstacles faced by the company is the high level of nonconformity on its production results. The waste on production process can be identified and classified into four types, i.e.: a). during the process of injection molding machines, b). finishing and cutting processes, c). quality control process and d). the packaging process. The objectives of this research are minimizing the defective goods and reducing the waste using Lean Six Sigma and FMEA approaches, especially for Bush product. From the analysis result, defective types on Bush product can be classified into bubble, speckle, short shoot, sunken, sink mark, over-cut, flashing, and discolor. Based on the attributes data on Bush product, the DPMO score is 988.42 or the sigma level is 4.6, While the DPMO score on the variable data on each dimension i.e.: a). Slit width on the bottom side has DPMO score of 30119 (sigma level 3.37), b). Diameter of the circle on the top side has DPMO score of 392294 (sigma level 1.77), c). Product thickness on the top side has DPMO score of 70474 (sigma level 2.97), d). Product height has DPMO score of 82107 (sigma level 2.89), product thickness on the bottom side has DPMO score of 24448 (sigma level 3.47), and f). Diameter of the circle on the bottom side has DPMO score of 24448 (sigma level 3.47). The highest RPN score on the dominant types of product defects which needs improvement are the defective goods of bubble type has RPN score of 729, flashing and the molten material out on the heating channel has RPN score of 384, over cutting has RPN score of 324 and sink mark has RPN score of 270. The recommendations for improvement that can be given from this research are making checklist for maintenance and production monitoring, enhancing work supervision and inspection, as well as improving the environment and work stations.

  9. Aminocaproic Acid Injection

    MedlinePlus

    Aminocaproic acid injection is used to control bleeding that occurs when blood clots are broken down too quickly. This ... the baby is ready to be born). Aminocaproic acid injection is also used to control bleeding in ...

  10. [Analysis suspected allergic factors to shenqi fuzheng injection based on prescription sequence analysis and nested case control study].

    PubMed

    Ai, Qing-Hua; Zeng, Xian-Bin; Xie, Yan-Ming; Yang, Wei

    2014-09-01

    This study based on twenty 3A grade hospital information system (HIS) database in China, adopt toprescription sequence analysis (PSA) with nested case control study (NCCS) to analysis mainly suspected allergy factor of Shenqi Fuzheng injection (Shenqi Fuzheng). Study design according to start to stop using Shenqi Fuzheng whether using dexamethasone injection will crowd divided into cases group and control group, each case matched 4 controls were selected, two groups according to the ratio of the age and sex matched well. Square test, Fisher exact test, single factor and multiple factor logistic regression were used to analyze data Condition on admission, allergic history, dosage and drug combinations were taken into account in cases of suspected allergic reactions. After analysis in two subgroups we found that the single dose (P = 0.000 2) and the combined use of matrine (P < 0.000 1, OR = 14.312, confidence interval [8.184, 25.029]) had significant effects on the suspected allergic reaction. Study on the existing HIS data and the study method based on screening suspected risk factors for allergic reaction. This study can provide guidance for Shenqi Fuzheng injection safety using in clinical practice, and it can also provides new method for the clinical safety reevaluation of post-marketing Chinese medicine injection. PMID:25532396

  11. Target injection methods for inertial fusion energy

    NASA Astrophysics Data System (ADS)

    Petzoldt, Ronald W.; Moir, Ralph W.

    1994-06-01

    We have studied four methods to inject IFE targets: the gas gun, electrostatic accelerator, induction accelerator, and rail gun. We recommend a gas gun for indirect drive targets because they can support a gas pressure load on one end and can slide along the gun barrel without damage. With the gas gun, the amount of gas required for each target (about 10 to 100 mg) is acceptable; for other types of targets, a sabot would be necessary. A cam and poppet valve arrangement is recommended for gas flow control. An electrostatic accelerator is attractive for use with lightweight spherical direct drive targets. Since there is no physical contact between the target and the injector, there will be no wear of either component during the injection process. An induction accelerator has an advantage of no electrical contact between the target and the injector. Physical contact is not even necessary, so the wear should be minimal. It requires a cylindrical conductive target sleeve which is a substantial added mass. A rail gun is a simpler device than an electrostatic accelerator or induction accelerator. It requires electrical contact between the target and the rails and may have a significant wear rate. The wear in a vacuum could be reduced by use of a solid lubricant such as MoS2. The total required accuracy of target injection, tracking and beam pointing of +/- 0.4 mm appears achievable but will require development and experimental verification.

  12. Target injection methods for inertial fusion energy

    SciTech Connect

    Petzoldt, R.W.; Moir, R.W.

    1994-06-01

    We have studied four methods to inject IFE targets: the gas gun, electrostatic accelerator, induction accelerator, and rail gun. We recommend a gas gun for indirect drive targets because they can support a gas pressure load on one end and can slide along the gun barrel without damage. With the gas gun, the amount of gas required for each target (about 10 to 100 mg) is acceptable; for other types of targets, a sabot would be necessary. A cam and poppet valve arrangement is recommended for gas flow control. An electrostatic accelerator is attractive for use with lightweight spherical direct drive targets. Since there is no physical contact between the target and the injector, there will be no wear of either component during the injection process. An induction accelerator has an advantage of no electrical contact between the target and the injector. Physical contact is not even necessary, so the wear should be minimal. It requires a cylindrical conductive target sleeve which is a substantial added mass. A rail gun is a simpler device than an electrostatic accelerator or induction accelerator. It requires electrical contact between the target and the rails and may have a significant wear rate. The wear in a vacuum could be reduced by use of a solid lubricant such as MoS{sub 2}. The total required accuracy of target injection, tracking and beam pointing of {plus_minus}0.4 mm appears achievable but will require development and experimental verification.

  13. Injectable Chemically Crosslinked Hydrogel for the Controlled Release of Bevacizumab in Vitreous: A 6-Month In Vivo Study

    PubMed Central

    Yu, Yu; Lau, Laurence Chi Ming; Lo, Amy Cheuk-yin; Chau, Ying

    2015-01-01

    can reduce the injection frequency, its associated complications, and treatment cost, which will be beneficial to both the patients and doctors. In this study, we showed that the in situ hydrogel-based controlled release system is a feasible option to tackle this problem. PMID:25774331

  14. Retrospective analysis of linear accelerator output constancy checks using process control techniques.

    PubMed

    Sanghangthum, Taweap; Suriyapee, Sivalee; Srisatit, Somyot; Pawlicki, Todd

    2013-01-01

    Shewhart control charts have previously been suggested as a process control tool for use in routine linear accelerator (linac) output verifications. However, a comprehensive approach to process control has not been investigated for linac output verifications. The purpose of this work is to investigate a comprehensive process control approach to linac output constancy quality assurance (QA). The RBA-3 dose constancy check was used to verify outputs of photon beams and electron beams delivered by a Varian Clinac 21EX linac. The data were collected during 2009 to 2010. Shewhart-type control charts, exponentially weighted moving average (EWMA) charts, and capability indices were applied to these processes. The Shewhart-type individuals chart (X-chart) was used and the number of data points used to calculate the control limits was varied. The parameters tested for the EWMA charts (smoothing parameter (λ) and the control limit width (L)) were λ = 0.05, L = 2.492; λ = 0.10, L = 2.703; and λ = 0.20, L = 2.860, as well as the number of points used to estimate the initial process mean and variation. Lastly, the number of in-control data points used to determine process capability (C(p)) and acceptability (C(pk)) were investigated, comparing the first in-control run to the longest in-control run of the process data. C(p) and C(pk) values greater than 1.0 were considered acceptable. The 95% confidence intervals were reported. The X-charts detected systematic errors (e.g., device setup errors). In-control run lengths on the X-charts varied from 5 to 30 output measurements (about one to seven months). EWMA charts showed in-control runs ranging from 9 to 33 output measurements (about two to eight months). The C(p) and C(pk) ratios are higher than 1.0 for all energies, except 12 and 20 MeV. However, 10 MV and 6, 9, and 16 MeV were in question when considering the 95% confidence limits. The X-chart should be calculated using 8-12 data points. For EWMA chart, using 4 data points

  15. Decay-Accelerating Factor Mitigates Controlled Hemorrhage-Instigated Intestinal and Lung Tissue Damage and Hyperkalemia in Swine

    PubMed Central

    Dalle Lucca, Jurandir J.; Simovic, Milomir; Li, Yansong; Moratz, Chantal; Falabella, Michael; Tsokos, George C.

    2012-01-01

    Background Activation of complement system has been associated with tissue injury after hemorrhage and resuscitation in rats and swine. This study investigated whether administration of human recombinant decay-accelerating factor (DAF; a complement regulatory protein that inhibits classical and alternative pathways) reduces tissue damage in a porcine model of hemorrhagic shock. Methods Male Yorkshire swine assigned to four groups were subjected to controlled, isobaric hemorrhage over 15 minutes to a target mean arterial pressure of 35 mmHg. Hypotension was maintained for 20 minutes followed by a bolus intravenous injection of DAF or vehicle then animals were observed for 200 minutes. Blood chemistry and physiological parameters were recorded. Tissue samples from lung and small intestine were subjected to histopathological evaluation and detection of tissue deposition of complement proteins by immunohistochemistry and Western blot analyses. Results Administration of DAF significantly reduced intestinal and lung tissue damage in a dose-dependent manner (5, 25, and 50 µg/kg). In addition, DAF treatment improved hemorrhage-induced hyperkalemia. The protective effects of DAF appear to be related to its ability to reduce tissue complement activation and deposition on affected tissues. Conclusions DAF treatment decreased tissue complement activation and deposition in hemorrhaged animals and attenuated tissue damage at 200 minutes post treatment. The observed beneficial effects of DAF treatment on tissue injury after 20 minutes of severe hypotension presents an attractive model of small volume resuscitation, particularly in situations with a restrictive medical logistical footprint such as far-forward access to first responders in the battlefield or in remote rural or mountainous environments. PMID:21795874

  16. Efficacy of tramadol and butorphanol pretreatment in reducing pain on propofol injection: A placebo-controlled randomized study

    PubMed Central

    Singh, Arvinderpal; Sharma, Geeta; Gupta, Ruchi; Kumari, Anita; Tikko, Deepika

    2016-01-01

    Background and Aims: Pain of propofol injection has been recalled by many patients as the most painful part of the induction of anesthesia. Tramadol and butorphanol are commonly used analgesics for perioperative analgesia in anesthesia practice. However, their potential to relieve propofol injection pain still needs to be explored. Material and Methods: A randomized, double-blind, placebo-controlled study was conducted on 90 American Society of Anesthesiologists I and II adult patients undergoing elective surgery under general anesthesia with propofol as an induction agent. Consecutive sampling technique with random assignment was used to allocate three groups of 30 patients each. Group I patients received an injection of normal saline 3 ml intravenously (placebo) while Group II and Group III patients received injection of tramadol 50 mg and butorphanol 1 mg intravenously, respectively. Before induction of anesthesia patients were asked about the intensity of pain on propofol injection by using visual analog scale (VAS) before the loss of consciousness. Descriptive statistics and analysis of variance with Chi-square test were used to analyze the data. The value of P < 0.05 was considered as a significant and P < 0.0001 as highly significant. Results: The incidence of pain in Group I was observed in 80% of the patients, while it was observed in 23.33% and 20% of patients in Group II and III, respectively. Mean VAS scores were 2.27 ± 1.51, 1.14 ± 1.74, and 1.03 ± 1.72 in Group I, II, and Group III patients, respectively. The incidence of pruritus was 10% and 6.7% and erythema in 13.2% and 6.7% in Group II and III, respectively. Conclusion: Pretreatment with both butorphanol and tramadol significantly reduced pain on propofol injection; however, they exhibited comparable efficacy among each other. Thus, either of these two drugs can be considered for pretreatment to reduce propofol injection pain. PMID:27006549

  17. The Texas Railroad Commission, Oil and Gas Division underground injection control program: A peer review

    SciTech Connect

    Not Available

    1989-01-01

    The reports included herein and any reports added subsequently are the result of an effort to evaluate the effectiveness of state programs to protect Underground Sources of Drinking Water (USDW) from potential contamination resulting from the operation of injection wells related to the production of oil and gas (Class II injection wells). The programs examined in this study cover wells which are used for the injection of fluids into oil reservoirs for the purpose of stimulating or furthering their production when natural production mechanisms decline or cease (enhanced recovery wells) and for the disposal of waters produced in conjunction with the production of oil and gas (disposal wells). The programs examined are those where primary enforcement authority has been delegated to the states by the US Environmental Protection Agency (EPA) under provisions of the Safe Drinking Water Act and EPA regulations (see following UIC Development Section of this report). The study was conducted under the auspices of the Underground Injection Practices Council (UIPC).

  18. Prototype demonstration of dual sorbent injection for acid gas control on municipal solid waste combustion units

    SciTech Connect

    1994-05-01

    This report gathered and evaluated emissions and operations data associated with furnace injection of dry hydrated lime and duct injection of dry sodium bicarbonate at a commercial, 1500 ton per day, waste-to-energy facility. The information compiled during the project sheds light on these sorbents to affect acid gas emissions from municipal solid waste combustors. The information assesses the capability of these systems to meet the 1990 Clean Air Act and 1991 EPA Emission Guidelines.

  19. On the Neutron Kinetics and Control of Accelerator-Driven Systems

    SciTech Connect

    Cacuci, D.G.

    2004-09-15

    This work addresses fundamental aspects of the time- and space-dependent behavior of an Accelerator-Driven Subcritical Core System (ADS) and presents a paradigm ADS neutron kinetics model that is solved exactly. Thus, this paradigm model can serve for benchmarking two- and/or three-dimensional computational tools. Furthermore, this work also proposes a global optimal control theory framework for the operation and control of an ADS. This framework encompasses conceptually the time- and space-dependent behavior of the ADS coupled neutron kinetics/thermal-hydraulic balance equations and aims at the optimal control of ADS operational objectives, which would include minimization of local flux disturbances, load and source following, etc. Importantly, this new conceptual framework makes no use of a 'fictitious ADS steady state' and yields the correct and complete (i.e., including sources) adjoint equations, without leaving any room for ambiguities. Thus, this new conceptual framework provides a natural basis for developing new computational methods and corresponding verification experiments specifically tailored for the control and operation of ADS.

  20. Slip Ratio Estimation and Regenerative Brake Control for Decelerating Electric Vehicles without Detection of Vehicle Velocity and Acceleration

    NASA Astrophysics Data System (ADS)

    Suzuki, Toru; Fujimoto, Hiroshi

    In slip ratio control systems, it is necessary to detect the vehicle velocity in order to obtain the slip ratio. However, it is very difficult to measure this velocity directly. We have proposed slip ratio estimation and control methods that do not require the vehicle velocity with acceleration. In this paper, the slip ratio estimation and control methods are proposed without detecting the vehicle velocity and acceleration when it is decelerating. We carried out simulations and experiments by using an electric vehicle to verify the effectiveness of the proposed method.

  1. Endoscopic injection therapy to prevent rebleeding from peptic ulcers with a protruding vessel: a controlled comparative trial.

    PubMed Central

    Rutgeerts, P; Gevers, A M; Hiele, M; Broeckaert, L; Vantrappen, G

    1993-01-01

    Seventy five patients with severely bleeding peptic ulcer were included in a controlled comparative trial to assess the efficacy and safety of endoscopic injection therapy in preventing rebleeding from peptic ulcers that presented at endoscopy with a protruding vessel. Twenty five patients were treated with injection of epinephrine followed by polidocanol, 25 were treated with injection of absolute alcohol, and 25 with sham injection. Rebleeding occurred in 44% of patients in the sham group, 40% of those treated with epinephrine and polidocanol, and in 20% of those treated with absolute ethanol. The difference in the haemostasis rate between the control and ethanol treated subjects nearly reached significance (p = 0.07). A second therapy session resulted in haemostasis rates of 68% in the epinephrine-polidocanol group and of 88% in the absolute ethanol group. These rates after two treatments as well as the emergency surgery rates (32% in the epinephrine-polidocanol group and 8% in the absolute ethanol group; p = 0.07) were not significantly different. In eight of the 11 patients with rebleeding in the sham treatment group, definitive haemostasis was achieved by elective injection therapy. Overall transfusion requirements were mean (SD) 6.0 (0.7) units in the sham group, 6.0 (0.9) in the epinephrine-polidocanol group, and 3.9 (0.5) in the absolute ethanol group. Only the difference between ethanol and sham was significant (p = 0.02). This study shows that injection with absolute ethanol reduces rebleeding in these patients and significantly lowers transfusion requirements. Absolute ethanol was superior to epinephrine-polidocanol, which was not significantly better than sham therapy. PMID:8472981

  2. Endoscopic local injection of ethanolamine oleate and thrombin as an effective treatment for bleeding duodenal ulcer: a controlled trial.

    PubMed Central

    Moretó, M; Zaballa, M; Suárez, M J; Ibáñez, S; Ojembarrena, E; Castillo, J M

    1992-01-01

    The injection of a mixture of ethanolamine oleate and thrombin as an effective treatment for bleeding duodenal ulcer was evaluated in 38 patients entered in a randomised prospective controlled trial. After a one week observation period, 1/19 (5.3%) treated patients and 11/19 (57.9%) control patients had suffered further bleeding (p less than 0.005; CI = 22%-74%). Emergency surgery was required in 1/19 in the treated group compared with 8/19 in the untreated group (CI = 13%-61%; p less than 0.05). The mean (SD) transfusion requirement in the treated group was 1.9 (0.5) U blood compared with 5.3 (0.7) U in the control group. No significant differences related to mortality were detected. In conclusion, local injection therapy is an effective means of haemostasis in patients with bleeding duodenal ulcer who are at risk of further bleeding. PMID:1582586

  3. Hydrogeologic controls on induced seismicity in crystalline basement rocks due to fluid injection into basal reservoirs.

    PubMed

    Zhang, Yipeng; Person, Mark; Rupp, John; Ellett, Kevin; Celia, Michael A; Gable, Carl W; Bowen, Brenda; Evans, James; Bandilla, Karl; Mozley, Peter; Dewers, Thomas; Elliot, Thomas

    2013-01-01

    A series of Mb 3.8-5.5 induced seismic events in the midcontinent region, United States, resulted from injection of fluid either into a basal sedimentary reservoir with no underlying confining unit or directly into the underlying crystalline basement complex. The earthquakes probably occurred along faults that were likely critically stressed within the crystalline basement. These faults were located at a considerable distance (up to 10 km) from the injection wells and head increases at the hypocenters were likely relatively small (∼70-150 m). We present a suite of simulations that use a simple hydrogeologic-geomechanical model to assess what hydrogeologic conditions promote or deter induced seismic events within the crystalline basement across the midcontinent. The presence of a confining unit beneath the injection reservoir horizon had the single largest effect in preventing induced seismicity within the underlying crystalline basement. For a crystalline basement having a permeability of 2 × 10(-17)  m(2) and specific storage coefficient of 10(-7) /m, injection at a rate of 5455 m(3) /d into the basal aquifer with no underlying basal seal over 10 years resulted in probable brittle failure to depths of about 0.6 km below the injection reservoir. Including a permeable (kz  = 10(-13)  m(2) ) Precambrian normal fault, located 20 m from the injection well, increased the depth of the failure region below the reservoir to 3 km. For a large permeability contrast between a Precambrian thrust fault (10(-12)  m(2) ) and the surrounding crystalline basement (10(-18)  m(2) ), the failure region can extend laterally 10 km away from the injection well. PMID:23745958

  4. Technical and economic evaluation of dry sorbent injection for SO/sub 2/ control using sodium compounds

    SciTech Connect

    Green, G.P.; Carr, R.C.; Hooper, R.G.

    1984-01-01

    Public Service Company of Colorado (PSCC) has committed to all-dry sorbent injection for SO/sub 2/ control on a new 500 MW coal-fired boiler, Pawnee Unit 2. Although no commitment has been made for construction of Pawnee 2, for engineering and planning purposes it is scheduled to begin service in 1990 burning western, low-sulfur, subbituminous coal. PSCC is currently the only electric utility to announce firm plans to employ this control technology. The purpose of this paper is to present the reasons for this commitment. It is hoped that this discussion will be of benefit to other electric utilities considering SO/sub 2/ control options.

  5. Effect of caudal epidural steroid or saline injection in chronic lumbar radiculopathy: multicentre, blinded, randomised controlled trial

    PubMed Central

    Solberg, Tore K; Romner, Bertil; Wilsgaard, Tom; Twisk, Jos; Anke, Audny; Nygaard, Øystein; Hasvold, Toralf; Ingebrigtsen, Tor

    2011-01-01

    Objective To assess the efficacy of caudal epidural steroid or saline injection in chronic lumbar radiculopathy in the short (6 weeks), intermediate (12 weeks), and long term (52 weeks). Design Multicentre, blinded, randomised controlled trial. Setting Outpatient multidisciplinary back clinics of five Norwegian hospitals. Participants Between October 2005 and February 2009, 461 patients assessed for inclusion (presenting with lumbar radiculopathy >12 weeks). 328 patients excluded for cauda equina syndrome, severe paresis, severe pain, previous spinal injection or surgery, deformity, pregnancy, ongoing breast feeding, warfarin therapy, ongoing treatment with non-steroidal anti-inflammatory drugs, body mass index >30, poorly controlled psychiatric conditions with possible secondary gain, and severe comorbidity. Interventions Subcutaneous sham injections of 2 mL 0.9% saline, caudal epidural injections of 30 mL 0.9% saline, and caudal epidural injections of 40 mg triamcinolone acetonide in 29 mL 0.9% saline. Participants received two injections with a two week interval. Main outcome measures Primary: Oswestry disability index scores. Secondary: European quality of life measure, visual analogue scale scores for low back pain and for leg pain. Results Power calculations required the inclusion of 41 patients per group. We did not allocate 17 of 133 eligible patients because their symptoms improved before randomisation. All groups improved after the interventions, but we found no statistical or clinical differences between the groups over time. For the sham group (n=40), estimated change in the Oswestry disability index from the adjusted baseline value was −4.7 (95% confidence intervals −0.6 to −8.8) at 6 weeks, −11.4 (−6.3 to −14.5) at 12 weeks, and −14.3 (−10.0 to −18.7) at 52 weeks. For the epidural saline intervention group (n=39) compared with the sham group, differences in primary outcome were −0.5 (−6.3 to 5.4) at 6 weeks, 1.4 (−4.5 to 7

  6. A randomized placebo-controlled trial of intradiscal methylene blue injection for the treatment of chronic discogenic low back pain.

    PubMed

    Peng, Baogan; Pang, Xiaodong; Wu, Ye; Zhao, Changcheng; Song, Xinghua

    2010-04-01

    A preliminary report of clinical study revealed that chronic discogenic low back pain could be treated by intradiscal methylene blue (MB) injection. We investigated the effect of intradiscal MB injection for the treatment of chronic discogenic low back pain in a randomized placebo-controlled trial. We recruited 136 patients who were found potentially eligible after clinical examination and 72 became eligible after discography. All the patients had discogenic low back pain lasting longer than 6 months, with no comorbidity. Thirty-six were allocated to intradiscal MB injection and 36 to placebo treatment. The principal criteria to judge the effectiveness included alleviation of pain, assessed by a 101-point numerical rating scale (NRS-101), and improvement in disability, as assessed with the Oswestry Disability Index (ODI) for functional recovery. At the 24-month follow-up, both the groups differed substantially with respect to the primary outcomes. The patients in MB injection group showed a mean reduction in pain measured by NRS of 52.50, a mean reduction in Oswestry disability scores of 35.58, and satisfaction rates of 91.6%, compared with 0.70%, 1.68%, and 14.3%, respectively, in placebo treatment group (p<0.001, p<0.001, and p<0.001, respectively). No adverse effects or complications were found in the group of patients treated with intradiscal MB injection. The current clinical trial indicates that the injection of methylene blue into the painful disc is a safe, effective and minimally invasive method for the treatment of intractable and incapacitating discogenic low back pain. PMID:20167430

  7. Diffusion and Controlled Localized Drug Release from an Injectable Solid Self-Assembling Peptide Hydrogel

    NASA Astrophysics Data System (ADS)

    Sun, Jessie E. P.; Stewart, Brandon; Langhans, Sigrid; Stewart, Joel P.; Pochan, Darrin J.

    2014-03-01

    We use an injectable solid peptide hydrogel (first assembled into a solid hydrogel, can shear-thin flow and immediately reheal on cessation of shear) as a drug delivery vehicle for sustained and active drug release. The triggered intramolecular peptide folding into a beta-hairpin leads to intermolecular assmebly of the peptides into the entangled and branched nanofibrillar hydrogel network responsible for its advantageous rheological properties. The hydrogel is used to encapsulate a highly effective chemotherapeutic, vincristine, with hydrophobic behavior. We show that we are able to constantly maintain drug release in low but still potent concentrations after the shear-thinning injection process. Similarly, the mechanical and morphoogical properties of the gels remains identical after injection. Characterization of the hydrogel construct is through tritiated vincristine release, TEM, confocal microscopy, and in vitro methods.

  8. Injection control of an XeF (C-A) laser - A simple scheme

    NASA Astrophysics Data System (ADS)

    Hollins, R. C.; Jordan, D. J.; Feltman, A.

    1987-07-01

    Enhancement of the efficiency of a blue-green discharge laser is demonstrated using a simple dye laser which is excited by the UV output of the XeF medium itself. The 350-nm output is harnessed to excite a small dye laser which acts as an injection source. The occurrence of optical gain on the C-A transition (440-520 nm) is delayed with respect to the UV output due to the initial presence of visible absorbing species, resulting in the automatic injection of dye-laser radiation into the XeF laser cavity at the appropriate time. With selection of the oscillation wavelength by the choice of dye, improvement of the efficiency by a factor of 30 is possible with the present self-excited injection scheme.

  9. Electric-field control of electromagnon propagation and spin-wave injection in a spiral multiferroic/ferromagnet composite

    SciTech Connect

    Chen, Hong-Bo; Li, You-Quan; Berakdar, Jamal

    2015-01-28

    We consider theoretically a composite chain consisting of a multiferroic helimagnet coupled to a conventional ferromagnet and inspect the conversion of electromagnon excitation into spin waves and vice versa. We demonstrate an electric-field control of spin-wave injection realized by electrically exciting an electromagnon that propagates with an intrinsic frequency larger than the gap of the spin wave in the ferromagnet. The efficiency of the conversion of the electromagnon into spin waves depends strongly on the strength of the magnetoelectric coupling at the interface and the intrinsic frequency of the multiferroic helimagnets. The phenomena predicted here suggest that a multiferroic/ferromagnet composite offers new opportunities for spin-wave injection, conversion, and control using electric field.

  10. Dulaglutide Injection

    MedlinePlus

    ... other body tissues where it is used for energy. Dulaglutide injection also works by slowing the movement ... In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at ...

  11. Liraglutide Injection

    MedlinePlus

    ... other body tissues where it is used for energy. Liraglutide injection also slows the emptying of the ... In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at ...

  12. Albiglutide Injection

    MedlinePlus

    ... other body tissues where it is used for energy. Albiglutide injection also works by slowing the movement ... In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at ...

  13. Rift strength controls rapid plate accelerations: A global analysis of Pangea fragmentation

    NASA Astrophysics Data System (ADS)

    Brune, S.; Williams, S.; Butterworth, N. P.; Müller, D.

    2015-12-01

    Motions of Earth's plates are thought to be driven by slab pull, basal drag, and ridge push. Here we propose that plate motions during supercontinental fragmentation are decisively controlled by the non-linear decay of a resistive force: rift strength. We use state-of-the-art global tectonic reconstructions and the new geotectonic analysis tool pyGPlates to analyze the transition from rifting to sea-floor spreading of well-studied post-Pangea rift systems (Central Atlantic, South Atlantic, Iberia/Newfoundland, Australia/Antarctica, North Atlantic, South China Sea, Gulf of California). In all cases, continental extension starts with a slow phase (< 10 mm/yr, full extension velocity) followed by a rapid acceleration over periods of a few My that introduces a fast rift phase (> 10 mm/yr). The transition from slow to fast extension takes place long before crustal break-up. In fact, we find that approximately half of the present day rifted margin area was created during the slow, and the other half during the fast phase. We reproduce the transition from slow to fast rifting using numerical forward models with force boundary conditions, such that rift velocities are not imposed but instead evolve naturally in response to changing strength of the rift. These models show that the two-phase velocity behavior during rifting and the rapid speed-up are intrinsic features of continental rupture that can be robustly inferred for different crust and mantle rheologies.It has been proposed that abrupt plate accelerations can be caused by plume-lithosphere interaction, subduction initiation, and slab detachment. However, none of these mechanisms explains our result that plate speed-up systematically precedes continental break-up. We therefore propose dynamic rift weakening as a new mechanism for rapid plate motion changes.

  14. A piezo-driven micro-inclination stage for calibration of a micro-acceleration transducer: structure and control strategy

    NASA Astrophysics Data System (ADS)

    Shao, Shubao; Song, Siyang; Xu, Minglong; Xie, Shilin; Li, Liang

    2016-02-01

    In some space applications, such as space navigation and vibration control of the large space structures, micro-acceleration transducers are required and have to be calibrated accurately. Unfortunately, providing extremely small static and quasi-static stimuli (accelerations) for the calibration of the micro-acceleration transducer has been a challenging task. This paper proposes a novel piezo-driven micro-inclination stage (PMIS) that can produce both discrete and continuous tumbles in a gravity field so that extremely small static and quasi-static stimuli (accelerations) can be obtained from a tiny component of the gravity constant. The proposed PMIS, which is driven by the lead zirconate titanate (PZT) stack, employs a rhombic mechanism to provide the PZT stack with a proper preload for the purpose of outputting a bidirectional force. To produce accurate static and quasi-static stimuli, the hysteresis non-linearity inherent in PZT stack is compensated by employing the strain feedback based adaptive control where the hysteresis property is identified online using the controlled auto-regressive moving average model. Furthermore, to improve the resolution of strain feedback, the strain sensitivity is maximized through structure optimization of the rhombic mechanism. The experimental results demonstrated that the proposed PMIS can produce minimal micro-inclination of {{0.1}\\prime \\prime} (corresponding to the induced micro-acceleration of 0.5μ g ) with the frequency ranging from 0 (DC) to 2 Hz.

  15. Center of Mass Acceleration Feedback Control of Functional Neuromuscular Stimulation for Standing in the Presence of Internal Postural Perturbations

    PubMed Central

    Audu, Musa L.; Triolo, Ronald J.

    2013-01-01

    This study determined the feasibility and performance of center of mass (COM) acceleration feedback control of a neuroprosthesis utilizing functional neuromuscular stimulation (FNS) to restore standing balance to a single subject paralyzed by a motor and sensory complete, thoracic-level spinal cord injury (SCI). An artificial neural network (ANN) was created to map gain-modulated changes in total body COM acceleration estimated from body-mounted sensors to optimal changes in stimulation required to maintain standing. Feedback gains were systematically tuned to minimize the upper extremity (UE) loads applied by the subject to an instrumented support device during internally generated postural perturbations produced by volitional reaching and object manipulation. Total body COM acceleration was accurately estimated (> 90% variance explained) from two three-dimensional (3-D) accelerometers mounted on the pelvis and torso. Compared to constant muscle stimulation employed clinically, COM acceleration feedback control of stimulation improved standing performance by reducing the UE loading required to resist internal postural disturbances by 27%. This case study suggests that COM acceleration feedback could potentially be advantageous in a standing neuroprosthesis since it can be implemented with only a few feedback parameters and requires minimal instrumentation for comprehensive, 3-D control of dynamic standing function. PMID:23299260

  16. Effect of breviscapine injection on clinical parameters in diabetic nephropathy: A meta-analysis of randomized controlled trials

    PubMed Central

    Liu, Xiaodan; Yao, Li; Sun, Da; Zhu, Xinwang; Liu, Qiang; Xu, Tianhua; Wang, Lining

    2016-01-01

    Diabetic nephropathy (DN) is currently a major public health problem worldwide. The objective of the present study was to evaluate the clinical effect of breviscapine injections in patients with DN. A meta-analysis was performed using the following databases to obtain published reports in any language: PubMed/MEDLINE, Embase, China National Knowledge Infrastructure, Chinese Evidence-Based Medicine, Wanfang Digital Periodicals, Chinese Academic Journals Full-text Database, Chinese Biological and Medical Database, China Doctoral and Masters Dissertations Full-text Database and the Chinese Proceedings of Conference Full-text Database. Two assessors independently reviewed each trial. A total of 35 randomized controlled trials, which performed studies on a total of 2,320 patients (1,188 in treatment groups and 1,132 in control groups), were included in the present meta-analysis. Data were analyzed using Stata version 11.0 for Windows. The results from the analysis demonstrated that breviscapine injections have greater therapeutic effects in patients with DN in comparison with the control group, including renal protective effects (reducing urine protein, serum creatinine and blood urea nitrogen) and adjustment for dyslipidemia (affecting levels of cholesterol, triglycerides and high density lipoproteins). These effects indicate that breviscapine injections are beneficial to patients with DN. Further studies are required to determine the mechanisms underlying the therapeutic effects of breviscapine. PMID:27588060

  17. A Well-Controlled Nucleus Pulposus Tissue Culture System with Injection Port for Evaluating Regenerative Therapies.

    PubMed

    Arkesteijn, Irene T M; Mouser, Vivian H M; Mwale, Fackson; van Dijk, Bart G M; Ito, Keita

    2016-05-01

    In vitro evaluation of nucleus pulposus (NP) tissue regeneration would be useful, but current systems for NP culture are not ideal for injections. The aim of this study was to develop a long-term culture system for NP tissue that allows injections of regenerative agents. Bovine caudal NPs were harvested and placed in the newly designed culture system. After equilibration of the tissue to 0.3 MPa the volume was fixed and the tissue was cultured for 28 days. The cell viability and extracellular matrix composition remained unchanged during the culture period and gene expression profiles were similar to those obtained in earlier studies. Furthermore, to test the responsiveness of bovine caudal NPs in the system, samples were cultured for 4 days and injected twice (day 1 and 3) with (1) PBS, (2) Link-N, for regeneration, and (3) TNF-α, for degeneration. It was shown that TNF-α increased COX2 gene expression, whereas no effect of Link-N was detected. In conclusion, the newly designed system allows long-term culture of NP tissue, wherein tissue reactions to injected stimulants can be observed. PMID:26294008

  18. Control of high-Z PFC erosion by local gas injection in DIII-D

    NASA Astrophysics Data System (ADS)

    Rudakov, D. L.; Stangeby, P. C.; Wong, C. P. C.; McLean, A. G.; Wampler, W. R.; Watkins, J. G.; Boedo, J. A.; Briesemeister, A.; Buchenauer, D. A.; Chrobak, C. P.; Elder, J. D.; Fenstermacher, M. E.; Guo, H. Y.; Lasnier, C. J.; Leonard, A. W.; Maingi, R.; Moyer, R. A.

    2015-08-01

    Reduced erosion of a high-Z PFC divertor surface was observed in DIII-D with local injection of methane and deuterium gases. Molybdenum-coated silicon samples were exposed in the lower divertor of DIII-D using DiMES under plasma conditions previously shown to cause significant net erosion of Mo. Three exposures with 13CH4 and one exposure with D2 gas injection about 12 cm upstream of the samples located within 1-2 cm of the attached strike point were performed. Reduction of Mo erosion was evidenced in-situ by the suppression of MoI line radiation at 386.4 nm once the gas injection started. Post-mortem ion beam analysis demonstrated that the net erosion of molybdenum near the center of the samples exposed with 13CH4 injection was below the measurement resolution of 0.5 nm, corresponding to a rate of ⩽0.04 nm/s. Compared to the previously measured erosion rates, this constitutes a reduction by a factor of >10.

  19. REACTIVATION OF SOLIDS FROM FURNACE INJECTION OF LIMESTONE FOR SO2 CONTROL

    EPA Science Inventory

    The paper gives results of a characterization of post-furnace injection solids and flyash mixtures and their testing in a bench-scale reactor for the removal of SO2. Virtually no SO2 removal was observed with untreated solids. High SO2 capture occurred when the samples were hydra...

  20. Spatially distributed control netowork for flow proportional chemical injection with center pivot irrigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The agricultural production practice of injecting a chemical into an operating irrigation system and applying it to the field area with the water is known as chemigation. Chemigation is a widely adopted practice with center pivot irrigation because it is relatively easy and is usually the least exp...