WorldWideScience

Sample records for beam injection

  1. Beam injection into RHIC

    International Nuclear Information System (INIS)

    During the RHIC sextant test in January 1997 beam was injected into a sixth of one of the rings for the first time. The authors describe the injection zone and its bottlenecks. They report on the commissioning of the injection system, on beam based measurements of the kickers and the application program to steer the beam

  2. ITER Neutral Beam Injection System

    International Nuclear Information System (INIS)

    A Japanese design proposal of the ITER Neutral Beam Injection System (NBS) which is consistent with the ITER common design requirements is described. The injection system is required to deliver a neutral deuterium beam of 75MW at 1.3MeV to the reactor plasma and utilized not only for plasma heating but also for current drive and current profile control. The injection system is composed of 9 modules, each of which is designed so as to inject a 1.3MeV, 10MW neutral beam. The most important point in the design is that the injection system is based on the utilization of a cesium-seeded volume negative ion source which can produce an intense negative ion beam with high current density at a low source operating pressure. The design value of the source is based on the experimental values achieved at JAERI. The utilization of the cesium-seeded volume source is essential to the design of an efficient and compact neutral beam injection system which satisfies the ITER common design requirements. The critical components to realize this design are the 1.3MeV, 17A electrostatic accelerator and the high voltage DC acceleration power supply, whose performances must be demonstrated prior to the construction of ITER NBI system. (author)

  3. ATF neutral beam injection system

    International Nuclear Information System (INIS)

    The Advanced Toroidal Facility is a stellarator torsatron being built at Oak Ridge National Laboratory to investigate improved plasma confinement schemes. Plasmas heating will be carried out predominantly by means of neutral beam injection. This paper describes the basic parameters of the injection system. Numerical calculations were done to optimize the aiming of the injectors. The results of these calculations and their implications on the neutral power to the machine are elaborated. The effects of improving the beam optics and altering the focal length on the power transmitted to the plasma are discussed

  4. TFTR neutral beam injection system conceptual design

    International Nuclear Information System (INIS)

    Three subsystems are described in the following chapters: (1) Neutral Beam Injection Line; (2) Power Supplies; and (3) Controls. Each chapter contains two sections: (1) Functions and Design Requirements; this is a brief listing of the requirements of components of the subsystem. (2) Design Description; this section describes the design and cost estimates. The overall performance requirements of the neutral beam injection system are summarized. (MOW)

  5. ATF neutral beam injection: optimization of beam alignment and aperturing

    International Nuclear Information System (INIS)

    The application of the existing Impurity Study Experiment (ISX-B) neutral beam injectors for the Advanced Toroidal Facility (ATF) is studied. It is determined that with the practical considerations of beam aperturing, ATF vacuum vessel complexity, and realistic beam modeling, the power absorbed by the plasma will be approximately 57% of the extracted neutral beam power, which corresponds to an injected power of about 1.5 MW. By reducing the beam divergence to a 10 Gaussian distribution, the absorbed power could be increased to 93%. The power delivered to the plasma is found to be a strong function of the beam divergence but only a weak function of the beam focal length. Shinethrough can be a serious problem if very low density startups are necessary. Preliminary calculations indicate that there will be no excessive fast-ion losses. 12 refs., 17 figs., 1 tab

  6. GRAVITY: beam stabilization and light injection subsystems

    CERN Document Server

    Pfuhl, O; Eisenhauer, F; Penka, D; Amorim, A; Kellner, S; Gillessen, S; Ott, T; Wieprecht, E; Sturm, E; Haussmann, F; Lippa, M; 10.1117/12.925391

    2012-01-01

    We present design results of the 2nd generation VLTI instrument GRAVITY beam stabilization and light injection subsystems. Designed to deliver micro-arcsecond astrometry, GRAVITY requires an unprecedented stability of the VLTI optical train. To meet the astrometric requirements, we have developed a dedicated 'laser guiding system', correcting the longitudinal and lateral pupil position as well as the image jitter. The actuators for the correction are provided by four 'fiber coupler' units located in the GRAVITY cryostat. Each fiber coupler picks the light of one telescope and stabilizes the beam. Furthermore each unit provides field de-rotation, polarization analysis as well as atmospheric piston correction. Using a novel roof prism design offers the possibility of on-axis as well as off-axis fringe tracking without changing the optical path. Finally the stabilized beam is injected with minimized losses into single-mode fibers via parabolic mirrors. We present lab results of the first guiding- as well as the ...

  7. GRAVITY: beam stabilization and light injection subsystems

    OpenAIRE

    Pfuhl, O.; Haug, M.; Eisenhauer, F.; Penka, D.; A. Amorim; Kellner, S.; Gillessen, S.; Ott, T; Wieprecht, E.; Sturm, E.; Haussmann, F.; Lippa, M.

    2012-01-01

    We present design results of the 2nd generation VLTI instrument GRAVITY beam stabilization and light injection subsystems. Designed to deliver micro-arcsecond astrometry, GRAVITY requires an unprecedented stability of the VLTI optical train. To meet the astrometric requirements, we have developed a dedicated 'laser guiding system', correcting the longitudinal and lateral pupil position as well as the image jitter. The actuators for the correction are provided by four 'fiber coupler' units loc...

  8. Design principles for high current beam injection lines

    International Nuclear Information System (INIS)

    We discuss the design principles for high current injection beam lines having a high degree of beam quality preservation. These principles are applied to designing a high current e-beam injection line delivering 10 MeV e-beams from the injector to an accelerator driving LTV FELs, as proposed at CEBAF

  9. TFTR neutral beam injected power measurement

    International Nuclear Information System (INIS)

    Energy flow within TFTR neutral beamlines is measured with a waterflow calorimetry system capable of simultaneously measuring the energy deposited within four heating beamlines (three ion sources each), or of measuring the energy deposited in a separate neutral beam test stand. Of the energy extracted from the ion source on the well-instrumented test stand, 99.5±3.5% can be accounted for. When the ion deflection magnet is energized, however, 6.5% of the extracted energy is lost. This loss is attributed to a spray of devious particles onto unmonitored surfaces. A 30% discrepancy is also observed between energy measurements on the internal beamline calorimeter and energy measurements on a calorimeter located in the test stand target chamber. Particle reflection from the flat plate calorimeter in the target chamber, which the incident beam strikes at a near-grazing angle of 12 degree, is the primary loss of this energy. A slight improvement in energy accountability is observed as the beam pulse length is increased. This improvement is attributed to systematic error in the sensitivity of the energy measurement to small fluctuations in the supply water temperature. An overall accuracy of 15% is estimated for the total power injected into TFTR. Contributions to this error are uncertainties in the beam neutralization efficiency, reionization and beam scrape-off in the drift duct, and fluctuations in the temperature of the supply water

  10. EDITORIAL: Negative ion based neutral beam injection

    Science.gov (United States)

    Hemsworth, R. S.

    2006-06-01

    It is widely recognized that neutral beam injection (NBI), i.e. the injection of high energy, high power, beams of H or D atoms, is a flexible and reliable system that has been the main heating system on a large variety of fusion devices, and NBI has been chosen as one of the three heating schemes of the International Tokomak Reactor (ITER). To date, all the NBI systems but two have been based on the neutralization (in a simple gas target) of positive hydrogen or deuterium ions accelerated to 1 MeV/nucleon. Unfortunately H- and D- are difficult to create, and the very characteristic that makes them attractive, the ease with which the electron is detached from the ion, means that it is difficult to create high concentrations or fluxes of them, and it is difficult to avoid substantial, collisional, losses in the extraction and acceleration processes. However, there has been impressive progress in negative ion sources and accelerators over the past decade, as demonstrated by the two pioneering, operational, multi-megawatt, negative ion based, NBI systems at LHD (180 keV, H0) and JT-60U (500 keV, D0), both in Japan. Nevertheless, the system proposed for ITER represents a substantial technological challenge as an increase is required in beam energy, to 1 MeV, D0, accelerated ion (D-) current, to 40 A, accelerated current density, 200 A m-2 of D-, and pulse length, to 1 h. At the Fourth IAEA Technical Meeting on Negative Ion Based Neutral Beam Injectors, hosted by the Consorzio RFX, Padova, Italy, 9-11 May 2005, the status of the R&D aimed at the realization of the injectors for ITER was presented. Because of the importance of this development to the success of the ITER project, participants at that meeting were asked if they were interested in rewriting and extending their contributions as a submission to Nuclear Fusion. Technology papers were accepted because of the very nature of the subject. The submissions underwent the regular double-referee peer-review process

  11. Challenges and plans for injection and beam dump

    CERN Document Server

    Barnes, M; Mertens, V; Uythoven, J

    2015-01-01

    The injection and beam dumping systems of the LHC will need to be upgraded to comply with the requirements of operation with the HL-LHC beams. The elements of the injection system concerned are the fixed and movable absorbers which protect the LHC in case of an injection kicker error and the injection kickers themselves. The beam dumping system elements under study are the absorbers which protect the aperture in case of an asynchronous beam dump and the beam absorber block. The operational limits of these elements and the new developments in the context of the HL-LHC project are described.

  12. Cascaded injection resonator for coherent beam combining of laser arrays

    Science.gov (United States)

    Kireev, Vassili [Sunnyvale, CA; Liu, Yun; Protopopescu, Vladimir [Knoxville, TN; Braiman, Yehuda [Oak Ridge, TN

    2008-10-21

    The invention provides a cascaded injection resonator for coherent beam combining of laser arrays. The resonator comprises a plurality of laser emitters arranged along at least one plane and a beam sampler for reflecting at least a portion of each laser beam that impinges on the beam sampler, the portion of each laser beam from one of the laser emitters being reflected back to another one of the laser emitters to cause a beam to be generated from the other one of the laser emitters to the beam reflector. The beam sampler also transmits a portion of each laser beam to produce a laser output beam such that a plurality of laser output beams of the same frequency are produced. An injection laser beam is directed to a first laser emitter to begin a process of generating and reflecting a laser beam from one laser emitter to another laser emitter in the plurality. A method of practicing the invention is also disclosed.

  13. Conceptual Design of Neutral Beam Injection System for EAST

    Science.gov (United States)

    Hu, Chundong; NBI Team

    2012-06-01

    Neutral beam injection (NBI) system with two neutral beam injections will be constructed on the Experimental Advanced Superconducting Tokamak (EAST) in two stages for high power auxiliary plasmas heating and non-inductive current drive. Each NBI can deliver 2~4 MW beam power with 50~80 keV beam energy in 10~100 s pulse length. Each elements of the NBI system are presented in this contribution.

  14. Rf beam loading in the Brookhaven AGS with booster injection

    International Nuclear Information System (INIS)

    Multi-batch bunched beam loading during injection from the Booster to the AGS will be discussed. The full intensity beam injection to the upgraded AGS rf system with beam phase and radial feedbacks will be studied. It is shown that a beam phase feedback is necessary in order to guarantee a predictable hewn behavior after the first batch injection, otherwise the initial phase deviation for the following batch injections cannot be controlled. However, the effectiveness of the phase feedback control of the transient beam loading may be limited by an emittance blow up in the process. It is shown that a fast power amplifier feedback with a moderate gain can significantly reduce the transient effect of the bunched beam injection

  15. Beam injection with pulsed multipole magnet at UVSOR-III

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, N., E-mail: naoto@nagoya-u.jp [Synchrotron Radiation Research Center, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aich 464-8603 (Japan); Zen, H. [Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Hosaka, M. [Synchrotron Radiation Research Center, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aich 464-8603 (Japan); Konomi, T. [UVSOR, Institute for Molecular Science, 38 Nishigo-Naka, Myodaiji, Okazaki 444-8585 (Japan); Adachi, M. [High Energy Accelerator Research Organization, KEK 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Hayashi, K.; Yamazaki, J. [UVSOR, Institute for Molecular Science, 38 Nishigo-Naka, Myodaiji, Okazaki 444-8585 (Japan); Takashima, Y. [Synchrotron Radiation Research Center, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aich 464-8603 (Japan); Katoh, M. [UVSOR, Institute for Molecular Science, 38 Nishigo-Naka, Myodaiji, Okazaki 444-8585 (Japan)

    2014-12-11

    In this study, we designed and manufactured a pulsed multipole magnet for beam injection into the UVSOR-III ring. A sextupole-like magnetic field could be excited when using the multipole magnet. To compensate for the residual field at the center of the magnet caused by manufacturing imprecisions, thin ferrite sheets were used. The injection experiments at UVSOR-III demonstrated multi-turn injections with the pulsed multipole magnet. The injection efficiency was 23% and the electron beam was stored up to the normal operation current of 300 mA. Moreover, we confirmed that oscillations of stored beams caused by beam injection were drastically suppressed compared with conventional pulsed dipole injection.

  16. Bootstrap current of fast ions in neutral beam injection heating

    International Nuclear Information System (INIS)

    The bootstrap current of fast ions produced by the neutral beam injection is investigated in a large aspect ratio tokamak with circular cross-section under specific parameters. The bootstrap current density distribution and the total bootstrap current are figured out. In addition, the beam bootstrap current always accompanies the electron return current due to the parallel momentum transfer from fast ions. With the electron return current considered, the net current density obviously decreases due to electron return current, at the same time the peak of current moves towards the centre plasma. Numerical results show that the value of the net current depends sensitively not only on the angle of the neutral beam injection but also on the ratio of the velocity of fast ions to the critical velocity: the value of net current is small for the neutral beam parallel injection but increases multipliedly for perpendicular injection, and increases with beam energy increasing. (authors)

  17. Efficient Injection of Electron Beams into Magnetic Guide Fields

    International Nuclear Information System (INIS)

    Preliminary experimental and modeling study of injection and transport of high current electron beams in current-neutralized background gas has been performed. Initial analysis of the results indicates that high current triaxial ring diode operates very reproducibly in the pinch mode. High current density beam can be injected efficiently into the drift region, using azimuthal guide field with reduced intensity near the injection region. This was shown to improve the effectiveness of capturing the beam for the transport. The transport length was insufficient to measure losses, such as would arise from scattering with the background gas

  18. Efficient Injection of Electron Beams into Magnetic Guide Fields

    Energy Technology Data Exchange (ETDEWEB)

    Chorny, V.; Cooperstein, G.; Dubyna, V.; Frolov, O.; Harper-Slaboszewicz, V.; Hinshelwood, D.; Schneider, R.; Solovyov, V.; Tsepilov, H.; Vitkovitsky, I.; Ware, K,

    1999-06-08

    Preliminary experimental and modeling study of injection and transport of high current electron beams in current-neutralized background gas has been performed. Initial analysis of the results indicates that high current triaxial ring diode operates very reproducibly in the pinch mode. High current density beam can be injected efficiently into the drift region, using azimuthal guide field with reduced intensity near the injection region. This was shown to improve the effectiveness of capturing the beam for the transport. The transport length was insufficient to measure losses, such as would arise from scattering with the background gas.

  19. Simulation of ion beam injection and extraction in an EBIS

    International Nuclear Information System (INIS)

    An example simulation of Au+ charge breeding using FAR-TECH’s integrated EBIS (electron beam ion source) modeling toolset is presented with the emphasis on ion beam injection and extraction. The trajectories of injected ions are calculated with PBGUNS (particle beam gun simulation) self-consistently by including the space charges from both ions and electrons. The ion beam, starting with initial conditions within the 100% acceptance of the electron beam, is then tracked by EBIS-PIC (particle-in-cell EBIS simulation code). In the trap, the evolution of the ion charge state distribution is estimated by charge state estimator. The extraction of charge bred ions is simulated with PBGUNS. The simulations of the ion injections show significant ion space charge effects on beam capture efficiency and the ionization efficiency

  20. Simulation of ion beam injection and extraction in an EBIS

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, L., E-mail: zhao@far-tech.com; Kim, J. S. [FAR-TECH, Inc., San Diego, California 92121 (United States)

    2016-02-15

    An example simulation of Au+ charge breeding using FAR-TECH’s integrated EBIS (electron beam ion source) modeling toolset is presented with the emphasis on ion beam injection and extraction. The trajectories of injected ions are calculated with PBGUNS (particle beam gun simulation) self-consistently by including the space charges from both ions and electrons. The ion beam, starting with initial conditions within the 100% acceptance of the electron beam, is then tracked by EBIS-PIC (particle-in-cell EBIS simulation code). In the trap, the evolution of the ion charge state distribution is estimated by charge state estimator. The extraction of charge bred ions is simulated with PBGUNS. The simulations of the ion injections show significant ion space charge effects on beam capture efficiency and the ionization efficiency.

  1. Simulation of ion beam injection and extraction in an EBIS

    Science.gov (United States)

    Zhao, L.; Kim, J. S.

    2016-02-01

    An example simulation of Au+ charge breeding using FAR-TECH's integrated EBIS (electron beam ion source) modeling toolset is presented with the emphasis on ion beam injection and extraction. The trajectories of injected ions are calculated with PBGUNS (particle beam gun simulation) self-consistently by including the space charges from both ions and electrons. The ion beam, starting with initial conditions within the 100% acceptance of the electron beam, is then tracked by EBIS-PIC (particle-in-cell EBIS simulation code). In the trap, the evolution of the ion charge state distribution is estimated by charge state estimator. The extraction of charge bred ions is simulated with PBGUNS. The simulations of the ion injections show significant ion space charge effects on beam capture efficiency and the ionization efficiency.

  2. High intensity ion beam injection into the 88-inch cyclotron

    OpenAIRE

    Wutte, Daniela; Clark, Dave J.; Laune, Bernard; Leitner, Matthaeus A.; Lyneis, Claude M.

    2000-01-01

    Low cross section experiments to produce super-heavy elements have increased the demand for high intensity heavy ion beams at energies of about 5 MeV/nucleon at the 88-Inch Cyclotron at the Lawrence Berkeley National Laboratory. Therefore, efforts are underway to increase the overall ion beam transmission through the axial injection line and the cyclotron. The ion beam emittance has been measured for various ion masses and charge states. Beam transport simulations including space charge ...

  3. Telemetry signal damping during rocket electron beam injections

    International Nuclear Information System (INIS)

    We present here a preliminary analysis of telemetry signal damping associated with the injection of intense energetic electron beams in the ionosphere during the Zarnitza 2 and Araks experiments. It is suggested that the damping of the signal is due to an enhancement of density fluctuations generated by the beam

  4. NOx reduction by electron beam-produced nitrogen atom injection

    Science.gov (United States)

    Penetrante, Bernardino M.

    2002-01-01

    Deactivated atomic nitrogen generated by an electron beam from a gas stream containing more than 99% N.sub.2 is injected at low temperatures into an engine exhaust to reduce NOx emissions. High NOx reduction efficiency is achieved with compact electron beam devices without use of a catalyst.

  5. Electronic beam steering of semiconductor injection lasers

    Science.gov (United States)

    Katz, J.

    1982-01-01

    A theoretical analysis of the problem of beam steering is presented. The required modifications of the dielectric constant profile of the laser structure were derived. A practical method for implementing the needed modifications is outlined.

  6. SPS transverse beam scraping and LHC injection losses

    CERN Document Server

    Drosdal, L; Bartmann, W; Bracco, C; Cornelis, K; Goddard, B; Meddahi, M; Veyrunes, E

    2012-01-01

    Machine protection sets strict requirements for the quality of the injected beam, in particular in the transverse plane. Losses at aperture restrictions and protection elements have to be kept at a minimum. Particles in the beam tails are lost at the tight transfer line collimators and can trigger the LHC beam abort system. These particles have to be removed by scrapers in the vertical and horizontal plane in the SPS. Scraping has become vital for high intensity LHC operation. This paper shows the dependence of injection quality on the SPS scraping and discusses an improved scraper setting up strategy for better reproducibility with the current scraper system.

  7. LHC Injection Beam Quality During LHC Run I

    CERN Document Server

    AUTHOR|(CDS)2079186; Stapnes, Steinar

    The LHC at CERN was designed to accelerate proton beams from 450 GeV to 7 TeV and collide them in four large experiments. The 450 GeV beam is extracted from the last pre-accelerator, the SPS, and injected into the LHC via two 3 km long transfer lines, TI 2 and TI 8. The injection process is critical in terms of preservation of beam quality and machine protection. During LHC Run I (2009-2013) the LHC was filled with twelve high intensity injections per ring, in batches of up to 144 bunches of 1.7*10^11 protons per bunch. The stored beam energy of such a batch is already an order of magnitude above the damage level of accelerator equipment. Strict quality and machine protection requirements at injection have a significant impact on operational efficiency. During the first years of LHC operation, the injection phase was identified as one of the limiting factors for fast LHC turnaround time. The LHC Injection Quality Check (IQC) software framework was developed as a part of this thesis to monitor the beam quality...

  8. Bootstrap current of fast ions in neutral beam injection heating

    International Nuclear Information System (INIS)

    The bootstrap current of fast ions produced by neutral beam injection (NBI) is investigated in a large-aspect-ratio tokamak with circular cross-section under specific parameters. The bootstrap current density distribution and the total bootstrap current are reported. In addition, the beam bootstrap current always accompanies the electron return current due to the parallel momentum transfer from fast ions. With the electron return current taken into consideration, the net current density obviously decreases; at the same time, the peak of the current moves towards the central plasma. Numerical results show that the value of the net current depends sensitively not only on the angle of the NBI but also on the ratio of the velocity of fast ions to the critical velocity: the value of the net current is small for neutral beam parallel injection, but increases severalfold for perpendicular injection, and increases with increasing beam energy. (paper)

  9. Thermal Transport in NCS Plasmas with Counter Neutral Beam Injection

    Science.gov (United States)

    Stallard, B. W.; Casper, T. A.; Greenfield, C. M.; Burrell, K. H.; Gohil, P.; Lohr, J.; Petty, C. C.; Synakowski, E.; Austin, M. E.; McKee, G. R.; Rettig, C. L.; Rhodes, T. L.; Zeng, L.

    1999-11-01

    Recent experiments in DIII-D have investigated internal transport barrier (ITB) formation with neutral beams injected in the counter-current direction, assisted by early ECH during current ramp up. For counter injection the v_torBT term for radial force balance adds to the nabla p term to determine E× B flow shear. Compared to ITB plasmas with co-current injection, characteristics with counter injection at similar beam power are: (a) broader profiles of T_I, T_e, n_e, and ω_tor within a larger barrier radius, (b) reduced profile gradients in the barrier region, and (c) about a factor of 2 higher Z_eff ( ~4) from the carbon impurity. In this paper profile evolution and results of transport analysis will be compared with co-injection plasmas.

  10. Neutral beam injection into mirror machines

    Energy Technology Data Exchange (ETDEWEB)

    Hooper, E.B. Jr.

    1976-08-01

    Neutral injection into 2XIIB has started and sustained a hot ion plasma of n/sub h/ = 10/sup 13/ - 10/sup 14/ cm/sup -3/ and anti E/sub i/ = 9 to 14 keV. The experiment and its interpretation are discussed.

  11. Development of the IHEP booster beam injection system

    International Nuclear Information System (INIS)

    A brief description of the IHEP synchrotron booster injection system equipment is given and results of experiments on two-turn injection are presented. The circuit of kicker-magnet switching is provided. At linear accelerator current of 80 mA the two-turn injection ensured the accumulation of 1.3 x 1012 proton/booster cycle; the total (per 29 injection cycles into the main accelerator) intensity of the accelerated beam in the booster bunch exceeded 2 X 1013, which is far in excess of the needs of the U-70 accelerator presently

  12. The fast beam interlock system for JET neutral injection

    International Nuclear Information System (INIS)

    The JET Neutral Beam Injection (NBI) system poses severe interlock problems with the possibility of unsafe conditions arising on a fast timescale. In order to cope with this the high-security Fast Beam Interlock System (FBIS) has been developed. It is used to turn off the beams in a failsafe manner when a condition arises which could damage the beam line or torus on a timescale too short to be dealt with by the JET Central Interlock and Safety System (CISS). FBIS interfaces signals from many JET safety systems and processes them to act directly on the Neutral Beam power supplies. The interfaces and the fail safety operation of FBIS are described. It is presently planned to upgrade the system to include a real-time comparison of the ion beam deflection magnet currents and the beam extraction voltage and a system which will compensate for the effects of the Tokamak stray fields on the NBI beamlines

  13. Development of ion source for neutral beam injection

    International Nuclear Information System (INIS)

    There are a few methods for further raising (secondary heating) toroidal plasma temperature above the limit of Joule heating of 1 to 2 keV. In this paper, the ion source used for neutral beam injection heating is described, which is now considered to be the most effective means as the secondary heating. It was reported that in Oak Ridge National Laboratory, neutral particle beam was injected into the torus and the plasma temperature increased as expected. Japan Atomic Energy Research Institute (JAERI) planned the plasma heating by neutral beam injection in JFT-2 torus from the summer of 1976 and it was decided that the heating by neutral beam injection is also employed in the critical plasma test facility (JT-60) which is scheduled to start operation in 1980. For this purpose, JAERI decided to build some test stand for ion source development including ITS-1 already prepared. At present, the test stand ITS-2 for the development of two stage acceleration ion source is ordered as a part of the development program of neutral beam injection heating for JT-60. This stand will be available for the test of ion sources of up to 100 kV, 20 A, and pulse width 1 sec. (Wakatsuki, Y.)

  14. Beam injection system into an electron ring compressor

    International Nuclear Information System (INIS)

    A system for three-turn injection of the beam into the electronic ring compressor is elaborated. The electron beam is rejected from the linear accelerator at an average energy of 1.5 MeV through the screening nozzle at a radius of 26 cm into the growing magnetic field. The energy of the injected electrons and the strength of the magnetic field are varied so that injection is always performed onto the equilibrium radius. In this case, the ring will feature an electron pulse spread of +-3.5% which makes it possible to accumulate up to 1013 particles in the ring, never exceeding the threshold of the azimuthal coherent non-stability. From the point of view of its design and technology, the injection system provides for creating superhigh vacuum of about 10-9 mm Hg in the compressor chamber which ensures the life of the ring of up to 2 ms

  15. An Introduction to the Supersonic Molecular Beam Injection

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Recently a new fuelling method with supersonic molecular beam injection (MBI) has been developed and used in the tokamaks experiments successfully. It is economical to develop and maintain. The advantages of supersonic MBI compared with the conventional of gas-puffing method are as follows: deep deposition of fuel, better fuelling efficiency, reduced recycling and pure plasma. Particle and energy confinement can be improved and density limit extended. This review described the Laval nozzle molecular beam and a simple collective model for the injection of a supersonic MBI into the tokamak plasma.

  16. On neutral-beam injection counter to the plasma current

    Science.gov (United States)

    Helander, P.; Akers, R. J.; Eriksson, L.-G.

    2005-11-01

    It is well known that when neutral beams inject ions into trapped orbits in a tokamak, the transfer of momentum between the beam and the plasma occurs through the torque exerted by a radial return current. It is shown that this implies that the angular momentum transferred to the plasma can be larger than the angular momentum of the beam, if the injection is in the opposite direction to the plasma current and the beam ions suffer orbit losses. On the Mega-Ampere Spherical Tokamak (MAST) [R. J. Akers, J. W. Ahn, G. Y. Antar, L. C. Appel, D. Applegate, C. Brickley et al., Plasma Phys. Controlled Fusion 45, A175 (2003)], this results in up to 30% larger momentum deposition with counterinjection than with co-injection, with substantially increased plasma rotation as a result. It is also shown that heating of the plasma (most probably of the ions) can occur even when the beam ions are lost before they have had time to slow down in the plasma. This is the dominant heating mechanism in the outer 40% of the MAST plasma during counterinjection.

  17. Colliding ionization injection in a beam driven plasma accelerator

    CERN Document Server

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

    2015-01-01

    The proposal of generating high quality electron bunches via ionization injection triggered by an counter propagating laser pulse inside a beam driven plasma wake is examined via two-dimensional particle-in-cell simulations. It is shown that electron bunches obtained using this technique can have extremely small slice energy spread, because each slice is mainly composed of electrons ionized at the same time. Another remarkable advantage is that the injection distance is changeable. A bunch with normalized emittance of 3.3 nm, slice energy spread of 15 keV and brightness of 7.2 A m$^{-2}$ rad$^{-2}$ is obtained with an optimal injection length which is achieved by adjusting the launch time of the drive beam or by changing the laser focal position. This makes the scheme a promising approach to generate high quality electron bunches for the fifth generation light source.

  18. Fast alternate beam injection from SPring-8 linac

    International Nuclear Information System (INIS)

    The electron beam from SPring-8 linac has been distributed to the booster synchrotron (Sy) of SPring-8 and New SUBARU (NS) of University of Hyogo. The beam direction from the linac had been changed every fifteen or twenty seconds in TopUp operation by sending command messages to network devices from central control room. Because the commands are software-based and executed successively one by one, it took about ten seconds to complete them. To change the beam routes every 0.5 seconds, we modified the timing system of linac and NS. NS timing system was changed to synchronize with that of Sy and gun trigger signals were modified to get time-shared for Sy and NS. The radiation safety system was also improved to fit faster alternate injection. These modifications were completed successfully in June 2013 and realized no wait injection of SR and NS. (author)

  19. Beam-Ion Confinement for Different Injection Angles

    Science.gov (United States)

    Heidbrink, W. W.; Petty, C. C.; van Zeeland, M. A.; Murakami, M.; Park, J. M.; Yu, J. H.

    2008-11-01

    DIII-D is equipped with neutral beam sources that inject in four different directions; in addition, the plasma can be shifted up or down to compare off-axis with on-axis injection. Fast-ion data for eight different conditions have been obtained: co/counter, near-tangential/near-perpendicular, on-axis/off-axis. Neutron measurements during short beam pulses assess prompt and delayed losses under low-power conditions. As expected, co-injection has fewer prompt losses than counter, tangential than perpendicular, and on-axis than off-axis; the differences are greater at low current than at higher current. Fast-ion Dα (FIDA) measurements diagnose the confinement at higher power. The inferred fast-ion density is higher during co-injection than during counter-injection, although the spatial profile is similar. Comparisons of two-dimensional FIDA images with simulations based upon classical fast-ion behavior show excellent agreement in the on-axis case. The inferred fast-ion diffusion during off-axis injection will be presented.

  20. Beam Coupling Impedance of the New Beam Screen of the LHC Injection Kicker Magnets

    CERN Document Server

    Day, H; Caspers, F; Métral, E; Salvant, B; Uythoven, J

    2014-01-01

    The LHC injection kicker magnets experienced significant beam induced heating of the ferrite yoke, with high beam currents circulating for many hours, during operation of the LHC in 2011 and 2012. The causes of this beam induced heating were studied in depth and an improved beam screen implemented to reduce the impedance. Results of measurements and simulations of the new beam screen design are presented in this paper: these are used to predict power loss for operation after long shutdown 1 and for proposed HL-LHC operational parameters.

  1. JET neutral beam injection system, construction and component tests

    International Nuclear Information System (INIS)

    The two neutral injection systems for JET are each determined by 40 mw beam power extracted from eight sources during 10 s pulses. Under the existing spatial restrictions, this has led to a complex beam-line system design. The applied manufacturing techniques and the approach to quality assurance are discussed. The beam sources have been operated at 80 kv, 60 a, 5 s in hydrogen. Plasma source development has increased the H+ yield to approximately 84%. Beamlet steering by aperture offset has experimentally been adjusted to the values required for the restricted tokamak entrance geometry. A beam source has also been operated at 160 kv, 37 a in deuterium. At the tokamak the 7 m high injector vacuum box has been installed incorporating a fast shutter and a cryopump. This LHE cooled pump with 40 m2 entrance area and 45% pumping efficiency has successfully been tested as well as the flexible cryoliquid transfer-lines. The bakeable valve between injector box and tokamak vacuum (1.1 m x 0.5 m gate cross-section) has been operated with leak rates <10-9 mbar1/s. The sub-system commissioning is completed by short-pulse operation of the beam sources with their final power supplies in situ at the tokamak and, in parallel to this, testing of the beam-line system in the neutral injection testbed

  2. Experimental investigation of molecular beam injection in HL-1 tokamak

    International Nuclear Information System (INIS)

    A new method of gas puffing is presented. The molecular beam, formed by high pressure deuterium gas through Larval nozzle and skimmer slit, is injected into the HL-1 vacuum vessel. The deuterium molecular current from the nozzle passing through the skimmer is about 3 x 1020/s. At the line average electron density of 5.2 x 1019 m-3, the beam velocity is about 100 m/s. As the plasma density and temperature increasing, the influxes of deuterium particles attenuate quickly. When the molecular beam injection (MBI) just returned to normal gas puffing, the Dα emission rapidly decreases, meanwhile, the particles move toward plasma center, the electron density is continuously peaking. The line average electron density rising lasts 45 ms. The thermal energy of plasma and confinement time for particles and energy are also increasing. the MBI is a direct and efficient gas fuelling mode, and the injected particles can reach to inside about 8 cm of plasma and q ≅ 2 confinement region. Its efficiency of injection is about 50%. After the MBI, the particle recycling coefficient R on the wall is 0.6 which is 10% lower than that of normal gas puffing

  3. Optic diagnosis of neutral beam injection on HL-1M

    Institute of Scientific and Technical Information of China (English)

    郑银甲; 冯震; 雷光玖; 姜韶风; 卢大伦; 罗俊林

    2002-01-01

    During the operation of a high-power neutral beam injection (NBI) system on the H L-1M tokamak, an optical diagnostic means using CCD camera was developed to characterize the NBI performance. The vacuum valve opening process and NBI period in the HL-1M experiment were displayed by a lot of photos taken with this means. Thus, the Hα emission profiles of the neutral beam (NB) and its interaction with plasma were given. Finally, the reason possible for plasma breakdown during NBI mode Ⅱ discharge was investigated. Therefore, this in-situ diagnosis can provide more information of the NBI.

  4. Injection line of 1+ ion beam for electron beam ion-charge breeding source and related beam elements

    International Nuclear Information System (INIS)

    Main purpose of the electron beam ion-charge breeding source (EBIBS) is to produce highly pure and highly charged ion beam from single charge ion of stable or radioactive species. It can accept low emittance ion beam from either online or offline ECR ion sources (ECRIS). The emittance of the extracted beam is low at lower RF frequencies and magnetic field of the ECRIS. The beam at the position of extraction is approximately reproduced at the entrance of the electron collector of the EBIBS. The beam moves forward under the influence of the negative potential deep of the electron beam and enters the ionization region in solenoid field of the EBIBS. The injection line starts at the extraction region of the ECRIS. The assumed parameters of the extracted beam of 20 keV energy and 0.0732 GeV/c momentum for injection are 10 mm diameter and 30 mrad beam divergence cone. As mass number of the ions decreases the energy decreases for constant momentum of the ion beam. The value of the momentum or the beam rigidity is judiciously chosen to encompass the most of the isotopes of various elements. The beam is focused by a quadrupole doublet and passes the beam through a 90° bending magnet. The beam is analyzed also by the dipole magnet to remove the contaminants and the selected ion beam is focused by a quadrupole doublet magnet to pass through an electrostatic 90° bending elements. The beam approaches the opening of 16 mm diameter of the electron collector. A round beam of 12 mm diameter is achieved here with the help of a quadrupole triplet through point-to-point imaging from start to the end. The transport matrices for the electrostatic bending elements were calculated and incorporated into the TRANSPORT code. (author)

  5. Conceptual design for the ZEPHYR neutral-beam injection system

    International Nuclear Information System (INIS)

    In June 1980, the Lawrence Berkeley Laboratory began a conceptual design study for a neutral beam injection system for the ZEPHYR ignition tokamak proposed by the Max-Planck-Institut fur Plasmaphysik in Garching, Germany. The ZEPHYR project was cancelled, and the LBL design effort concluded prematurely in January 1981. This report describes the conceptual design as it existed at that time, and gives brief consideration to a schedule, but does not deal with costs

  6. Beam-ion confinement for different injection geometries

    Science.gov (United States)

    Heidbrink, W. W.; Murakami, M.; Park, J. M.; Petty, C. C.; Van Zeeland, M. A.; Yu, J. H.; McKee, G. R.

    2009-12-01

    The DIII-D tokamak is equipped with neutral beam sources that inject in four different directions; in addition, the plasma can be moved up or down to compare off-axis with on-axis injection. Fast-ion data for eight different conditions have been obtained: co/counter, near-tangential/near-perpendicular and on-axis/off-axis. Neutron measurements during short beam pulses assess prompt and delayed losses under low-power conditions. As expected, co-injection has fewer losses than counter, tangential fewer than perpendicular and on-axis fewer than off-axis; the differences are greater at low current than at higher current. The helicity of the magnetic field has a weak effect on the overall confinement. Fast-ion Dα (FIDA) and neutron measurements diagnose the confinement at higher power. The basic trends are the same as in low-power plasmas but, even in plasmas without long wavelength Alfvén modes or other MHD, discrepancies with theory are observed, especially in higher temperature plasmas. At modest temperature, two-dimensional images of the FIDA light are in good agreement with the simulations for both on-axis and off-axis injection. Discrepancies with theory are more pronounced at low fast-ion energy and at high plasma temperature, suggesting that fast-ion transport by microturbulence is responsible for the anomalies.

  7. Spheromak Energy Transport Studies via Neutral Beam Injection

    Energy Technology Data Exchange (ETDEWEB)

    McLean, H S; Hill, D N; Wood, R D; Jayakumar, J; Pearlstein, L D

    2008-02-11

    Results from the SSPX spheromak experiment provide strong motivation to add neutral beam injection (NBI) heating. Such auxiliary heating would significantly advance the capability to study the physics of energy transport and pressure limits for the spheromak. This LDRD project develops the physics basis for using NBI to heat spheromak plasmas in SSPX. The work encompasses three activities: (1) numerical simulation to make quantitative predictions of the effect of adding beams to SSPX, (2) using the SSPX spheromak and theory/modeling to develop potential target plasmas suitable for future application of neutral beam heating, and (3) developing diagnostics to provide the measurements needed for transport calculations. These activities are reported in several publications.

  8. Mechanical Design of the Injection Beam Line of Small Medical Cyclotron

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The injection beam line is a key device for beam transport of the small medical cyclotron, giving direct influence to the beam quality of the cyclotron. According to the medical needs of the cyclotron, the overall length of the injection beam line is as short as possible,

  9. TFTR [Tokamak Fusion Test Reactor] neutral beam injected power measurement

    International Nuclear Information System (INIS)

    Energy flow within TFTR neutral beamlines is measured with a waterfall calorimetry system capable of simultaneously measuring the energy deposited within four heating beamlines (three ion sources each), or of measuring the energy deposited in a separate neutral beam test stand. Of the energy extracted from the ion source in the well instrumented test stand, 99.5 +- 3.5% can be accounted for. When the ion deflection magnet is energized, however, 6.5% of the extracted energy is lost. This loss is attributed to a spray of devious particles onto unmonitored surfaces. A 30% discrepancy is also observed between energy measurements on the internal beamline calorimeter and energy measurements on a calorimeter located in the test stand target chamber. Particle reflection from the flat plate calorimeter in the target chamber, which the incident beam strikes at a near-grazing angle of 12/degree/, is the primary loss of this energy. A slight improvement in energy accountability is observed as the beam pulse length is increased. This improvement is attributed to systematic error in the sensitivity of the energy measurement to small fluctuations on the supply water temperature. An overall accuracy of 15% is estimated for the total power injected into TFTR. Contributions to this error are uncertainties in the beam neutralization efficiency, reionization and beam scrape-off in the drift duct, and fluctuations in the temperature of the supply water. 28 refs., 9 figs., 1 tab

  10. Influence of injection beam emittance on beam transmission efficiency in a cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Kurashima, Satoshi, E-mail: kurashima.satoshi@jaea.go.jp; Kashiwagi, Hirotsugu; Miyawaki, Nobumasa; Yoshida, Ken-Ichi; Okumura, Susumu [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency, 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan)

    2014-02-15

    The JAEA AVF cyclotron accelerates various kinds of high-energy ion beams for research in biotechnology and materials science. Beam intensities of an ion species of the order of 10{sup −9}–10{sup −6} ampere are often required for various experiments performed sequentially over a day. To provide ion beams with sufficient intensity and stability, an operator has to retune an ion source in a short time. However, the beam intensity downstream of the cyclotron rarely increases in proportion to the intensity at the ion source. To understand the cause of this beam behavior, transmission efficiencies of a {sup 12}C{sup 5+} beam from an electron cyclotron resonance ion source to the cyclotron were measured for various conditions of the ion source. Moreover, a feasible region for acceleration in the emittance of the injection beam was clarified using a transverse-acceptance measuring system. We confirmed that the beam emittance and profile were changed depending on the condition of the ion source and that matching between the beam emittance and the acceptance of the cyclotron was degraded. However, after fine-tuning to improve the matching, beam intensity downstream of the cyclotron increased.

  11. Energy Spread of the Proton Beam in the Fermilab Booster at its Injection Energy

    Energy Technology Data Exchange (ETDEWEB)

    Bhat, C. M. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Chase, B. E. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Chaurize, S. J. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Garcia, F. G. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Seiya, K. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Pellico, W. A. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Sullivan, T. M. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Triplett, A. K. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2015-04-27

    We have measured the energy spread of the Booster beam at its injection energy of 400 MeV by three different methods: (1) creating a notch of about 40 nsec wide in the beam immediately after multiple turn injection and measuring the slippage time required for high and low momentum particles for a grazing touch in line-charge distribution, (2) injecting partial turn beam and letting it to debunch, and (3) comparing the beam profile monitor data with predictions from MAD simulations for the 400 MeV injection beam line. The measurements are repeated under varieties of conditions of rf systems in the ring and in the beam transfer line.

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Akbar Fakhri, Ali; Prajapati, S. K.; Ghodke, A. D.; Singh, Gurnam [Raja Ramanna Centre for Advanced Technology, Indore 452013 (India)

    2013-08-15

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

  14. Injection of intense ion beam into a tokamak

    International Nuclear Information System (INIS)

    We describe an experiment to investigate the direct injection of an intense ion beam into a tokamak by means of the polarization drift. Confinement of 100 keV ions in the UCI tokamak (r = 15 cm, R = 60 cm, B/sub T/ = 6 kG) requires operation with a plasma current of 56 kA corresponding to q (limiter) = 2. Trapped ions are to be detected by a charge-exchange analyzer. The present status of the experiment will be discussed

  15. Conceptual design of the JT-60 neutral beam injection system (interim report)

    International Nuclear Information System (INIS)

    This is an interim report on conceptual design of the JT-60 neutral beam injection system. Requirements for the JT-60 neutral beam injector are injection of a 20 MW neutral hydrogen beam into the plasma in the vicinity of energy 75 keV as long as 10 sec, keeping thermal gas flow rate into the torus vacuum chamber below 15% the neutral beam flux. On the basis of these requirements and recent results of research and development of ion sources and beam line components, system conceptual design is now proceeding. Scale of the JT-60 neutral beam injection system is discussed, indicating also future problems. (auth.)

  16. OTR Based Monitor of Injection Beam for Top-Up Operation of the SPring-8

    CERN Document Server

    Takano, S; Masuda, T; Yamashita, A

    2005-01-01

    We have developed an OTR based monitor of injection beam at the SPring-8. The monitor has been installed near the injection point of the storage ring downstream of the beam transport line from the booster synchrotron. A screen made of an aluminum coated polyimide film is used as a nondestructive OTR radiator. A CCD camera with an electric shutter is used to observe the OTR image of the injection beam. The electric shutter is synchronized with the external injection trigger signals. At every injection, the image signal from the CCD camera is captured and analyzed by a personal computer, and the position, size and intensity of the injection beam are recorded by the common database of the SPring-8 control system. The OTR injection beam monitor provides real time and continuous diagnostic tool useful for the top-up operation of the SPring-8 storage ring.

  17. Inertial fusion energy target injection, tracking, and beam pointing

    Energy Technology Data Exchange (ETDEWEB)

    Petzoldt, R.W.

    1995-03-07

    Several cryogenic targets must be injected each second into a reaction chamber. Required target speed is about 100 m/s. Required accuracy of the driver beams on target is a few hundred micrometers. Fuel strength is calculated to allow acceleration in excess of 10,000 m/s{sup 2} if the fuel temperature is less than 17 K. A 0.1 {mu}m thick dual membrane will allow nearly 2,000 m/s{sup 2} acceleration. Acceleration is gradually increased and decreased over a few membrane oscillation periods (a few ms), to avoid added stress from vibrations which could otherwise cause a factor of two decrease in allowed acceleration. Movable shielding allows multiple targets to be in flight toward the reaction chamber at once while minimizing neutron heating of subsequent targets. The use of multiple injectors is recommended for redundancy which increases availability and allows a higher pulse rate. Gas gun, rail gun, induction accelerator, and electrostatic accelerator target injection devices are studied, and compared. A gas gun is the preferred device for indirect-drive targets due to its simplicity and proven reliability. With the gas gun, the amount of gas required for each target (about 10 to 100 mg) is acceptable. A revolver loading mechanism is recommended with a cam operated poppet valve to control the gas flow. Cutting vents near the muzzle of the gas gun barrel is recommended to improve accuracy and aid gas pumping. If a railgun is used, we recommend an externally applied magnetic field to reduce required current by an order of magnitude. Optical target tracking is recommended. Up/down counters are suggested to predict target arrival time. Target steering is shown to be feasible and would avoid the need to actively point the beams. Calculations show that induced tumble from electrostatically steering the target is not excessive.

  18. Inertial fusion energy target injection, tracking, and beam pointing

    International Nuclear Information System (INIS)

    Several cryogenic targets must be injected each second into a reaction chamber. Required target speed is about 100 m/s. Required accuracy of the driver beams on target is a few hundred micrometers. Fuel strength is calculated to allow acceleration in excess of 10,000 m/s2 if the fuel temperature is less than 17 K. A 0.1 μm thick dual membrane will allow nearly 2,000 m/s2 acceleration. Acceleration is gradually increased and decreased over a few membrane oscillation periods (a few ms), to avoid added stress from vibrations which could otherwise cause a factor of two decrease in allowed acceleration. Movable shielding allows multiple targets to be in flight toward the reaction chamber at once while minimizing neutron heating of subsequent targets. The use of multiple injectors is recommended for redundancy which increases availability and allows a higher pulse rate. Gas gun, rail gun, induction accelerator, and electrostatic accelerator target injection devices are studied, and compared. A gas gun is the preferred device for indirect-drive targets due to its simplicity and proven reliability. With the gas gun, the amount of gas required for each target (about 10 to 100 mg) is acceptable. A revolver loading mechanism is recommended with a cam operated poppet valve to control the gas flow. Cutting vents near the muzzle of the gas gun barrel is recommended to improve accuracy and aid gas pumping. If a railgun is used, we recommend an externally applied magnetic field to reduce required current by an order of magnitude. Optical target tracking is recommended. Up/down counters are suggested to predict target arrival time. Target steering is shown to be feasible and would avoid the need to actively point the beams. Calculations show that induced tumble from electrostatically steering the target is not excessive

  19. Experiments with electron beam injection in ionosphere plasma and rare gas

    International Nuclear Information System (INIS)

    The active experiment 'Electron' is intended for the electron beam injection from a meteorological rocket in the ionosphere plasma. The beam is injected in the ionosphere plasma at a current of 0.5 A and an energy of 6.5 - 8 keV. The energy spectra are given for the plasma electrons and ions. The radio-wave spectrum is measured in a RF frequency range of 100-500 MHz. The radio wave traversing through the electron beam injection region is discussed. The laboratory experiments are performed with the electron beam injection in a rare gas to model the active outer-space experiments

  20. Reduction in TFTR [Tokamak Fusion Test Reactor] fusion reaction rate by unbalanced beam injection and rotation

    International Nuclear Information System (INIS)

    In TFTR plasmas at low to moderate density, the highest fusion energy gain Q/sub dd/ (D-D fusion power/injected power P/sub b/) is obtained with nearly balanced co- and counter-injection of neutral beams. For a given beam power, significantly unbalanced injection reduces Q/sub dd/ because the accompanying plasma rotation reduces the beam-target fusion reactivity, the fast-ion slowing-down time, and the beam-beam reaction rate, while and decrease from their maximum values. 9 refs., 3 figs., 1 tab

  1. Turn-by-Turn Analysis of Proton and Gold Beams at Injection in the AGS Booster

    International Nuclear Information System (INIS)

    In this paper the authors describe the latest version of a program they have used for several years to acquire and analyze turn-by-turn data from pick-up electrodes in the AGS Booster during injection. The program determines several parameters of the injected beam including the tunes and the position and angle of the incoming beam. Examples are given for both proton and gold injection

  2. Transient beam losses in the LHC injection kickers from micron scale dust particles

    CERN Document Server

    Goddard, B; Baer, T; Barnes, M J; Cerutti, F; Ferrari, A; Garrel, N; Gerardin, A; Guinchard, M; Lechner, A; Masi, A; Mertens, V; Morón Ballester, R; Redaelli, S; Uythoven, J; Vlachoudis, V; Zimmermann, F

    2012-01-01

    Transient beam losses on a time scale of a few ms have been observed in the LHC injection kickers, occurring mainly shortly after beam injection with a strong correlation in time to the kicker pulsing. The beam losses, which have at times affected LHC availability, are attributed to micron scale ceramic dust particles detached from the alumina beam pipe and accelerated into the beam. The beam related observations are described, together with laboratory measurements of beam pipe contamination and kicker vibration, simulations of electric field in the beam pipe and the basic dynamic model. Energy deposition simulations modelling the beam losses are presented and compared to measurement. Extrapolations to future LHC operation at higher intensities and energies are made, and prospects for mitigation are discussed.

  3. Use of off-axis injection as an alternative to geometrically merging beams in an energy-recovering linac

    Science.gov (United States)

    Douglas, David R.

    2012-01-10

    A method of using off-axis particle beam injection in energy-recovering linear accelerators that increases operational efficiency while eliminating the need to merge the high energy re-circulating beam with an injected low energy beam. In this arrangement, the high energy re-circulating beam and the low energy beam are manipulated such that they are within a predetermined distance from one another and then the two immerged beams are injected into the linac and propagated through the system. The configuration permits injection without geometric beam merging as well as decelerated beam extraction without the use of typical beamline elements.

  4. Beam shaping element for compact fiber injection systems

    Energy Technology Data Exchange (ETDEWEB)

    Weichman, L.S.; Dickey, F.M.; Shagam, R.N.

    2000-01-05

    Injection of high power, multi-mode laser profiles into a fiber optic delivery system requires controlling a number of injection parameters to maximize throughput and minimize concerns for optical damage both at the entrance and exit faces of the fiber optic. A simple method for simultaneously achieving a compact fiber injection geometry and control of these injection parameters, independent of the input source characteristics, is provided by a refractive lenslet array and simple injection lens configuration. Design criteria together with analytical and experimental results for the refractive lenslet array and short focal length injection lens are presented. This arrangement provides a uniform spatial intensity distribution at the fiber injection plane to a large degree independent of the source mode structure, spatial profile, divergence, size, and/or alignment to the injection system. This technique has application to a number of laser systems where uniform illumination of a target or remote delivery of high peak power is desired.

  5. Enhancement of neutral beam deposition in hydrogen discharge using carbon pellet injection in LHD

    International Nuclear Information System (INIS)

    The central ion temperature in the large helical device (LHD), as measured by charge-exchange recombination spectroscopy, has been improved to a record 5.6 keV by combining 21 MW of neutral beam heating with the injection of a carbon pellet. The intensity of the neutral beam emission of the hydrogen Balmer line (Hα: n=3 → 2) was observed to weaken along the beam injection axis following the carbon pellet injection due to the increased beam attenuation. The beam-emission intensity was reconstructed by calculating the density distribution, and the beam-stopping coefficients, along a beam injection axis and was found to fit well to the measured beam-emission for a mixed hydrogen and carbon target plasma. The dynamics of the neutral beam deposition power and the carbon fraction were estimated from the beam-emission measurements using data from ADAS. We conclude that the beam deposition power in a carbon pellet discharge is enhanced over that of a pure hydrogen discharge. (author)

  6. Preliminary experiment of neutral beam injection heating in JIPP T-II stellarator

    International Nuclear Information System (INIS)

    Neutral beam injection experiments are carried out in JIPP T-II, which is a hybrid device of stellarator and tokamak. Two neutral beam injectors are equipped tangentially in the direction of co- and counter-injections. Hydrogen neutral beams of 22 keV, 60 kW (co-injection) and 30 kW (counter-injection) are applied to the ohmically heated stellarator plasma and also to the tokamak plasma. The bulk ion heating efficiency for co-injection is around 1.6 eV/kW in the case of stellarator and 1.9 eV/kW in the case of tokamak, while the heating efficiencies for counter-injection are about 1.6 eV/kW in both cases. The difference between the tokamak and stellarator is considered to be caused by the enhanced orbit loss due to the helical ripples in the stellarator. (author)

  7. Results and analysis of the TMX electron-beam injection experiments

    Energy Technology Data Exchange (ETDEWEB)

    Poulsen, P.; Grubb, D.P.

    1980-08-01

    Electron beams (e-beams) were injected into the Tandem Mirror Experiment (TMX) plasma in order to investigate the effect on the ion cyclotron fluctuations of the plasma. The power level of the e-beams was comparable to that of the injected neutral beams. It was found that injection of the e-beams produced no significant effect on the ion cyclotron fluctuations, the measured plasma parameters, or the particle and power flow of the plasma. The increase in bulk electron temperature and the production of mirror-confined electrons found in previous experiments in which e-beams were injected into a mirror-confined plasma were not observed in this experiment. Analysis of the regions and frequencies of wave creation and absorption within the plasma shows that the plasma density and magnetic field profiles through the plasma strongly affect the resonances encountered by the waves. The steep axial density profiles produced by neutral-beam injection in the TMX experiment are not conducive to efficient coupling of the e-beam energy to the plasma.

  8. Laser ion source: A direct plasma injection scheme for two-beam type interdigital-H radio frequency quadrupole linac

    International Nuclear Information System (INIS)

    We developed a laser ion source using a direct plasma injection scheme (DPIS) as an injection system for a two-beam type radio frequency quadrupole (RFQ) linac with an interdigital-H (IH) type cavity. The laser ion source in the DPIS is directly connected to the RFQ cavity without the low energy beam transport system. We achieved a high current C2+ beam above 60 mA per beam channel from the ion source. The beam will be injected to the two-beam type IH-RFQ linac, and the linac will generate a beam current of approximately 44 mA per beam channel.

  9. Analysis of fusion neutron production in EAST with neutral beam injection

    International Nuclear Information System (INIS)

    Background: The neutron emission rate increases rapidly with high-power deuterium beam injected into deuterium plasmas. It is necessary to calculate the neutron production in Experimental Advanced Superconducting Tokamak (EAST) for the radiation safety. Purpose: We aim to provide reference for developing new detection systems of fusion neutron and neutron radiation shielding design. Methods: Neutron emission rate was calculated using the typical particle model and analysis method. The relationships were analyzed among the fusion neutron production and the ion density, ion temperature, neutral beam energy and neutral beam power respectively. Results: The results demonstrated that the total fusion neutron production was 1016 n·s-1 with 80-keV, 4-MW neutral beam injection. Conclusion: Neutron intensity in EAST will increase by a factor of ten when appropriate neutral beam injection is applied. It can be referred for further performance improvement and radiation protection of EAST. (authors)

  10. Preliminary test experiment for electron beam injection to JSR

    International Nuclear Information System (INIS)

    A preliminary test experiment has been carried out to investigate the property of electron beam from the JAERI linac which will be used as an injector for the JSR(JAERI Storage Ring). The electron beam was obtained within the energy resolution of 1.55 % and the peak current of 38 mA at 150 MeV. (author)

  11. Simulations of LEIR Injection Line Beam Position Monitors

    CERN Document Server

    Maltseva, Mariya

    2016-01-01

    In this paper sensitivity characteristics of a beam position monitor are described. Characteristics are obtained during the simulations in CST Studio, the results are compared with the calculated values. The results for a low-beta beam and with a wire are compared.

  12. Neutral beam injection system design for KSTAR tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Choi, B.H.; Lee, K.W.; Chung, K.S.; Oh, B.H.; Cho, Y.S.; Bae, Y.D.; Han, J.M. [Korea Atomic Energy Research Institute, Taejon (Korea)

    1998-06-01

    The NBI system for KSTAR (Korean Superconducting Tokamak Advanced Research) has been designed based on conventional positive ion beam technology. One beam line consists of three ion sources, three neutralizers, one bending magnet, and one drift tube. This system will deliver 8 MW deuterium beam to KSTAR plasma in normal operation to support the advanced experiments on heating, current drive and profile control. The key technical issues in this design were high power ion source(120 kV, 65 A), long pulse operation (300 seconds; world record is 30 sec), and beam rotation from vertical to horizontal direction. The suggested important R and D points on ion source and beam line components are also included. (author). 7 refs., 27 figs., 1 tab.

  13. Bunch-to-bucket injection of linac beam into the Brookhaven AGS

    International Nuclear Information System (INIS)

    A new fast beam chopper has been used to study injection and capture in the AGS. The chopper is a fast beam switch with 10 ns rise and fall times that can be programmed on a bunch-by-bunch basis and is synchronized to the net accelerating voltage of the synchrotron, thus allowing bunch-to-bucket injection of the 200 MeV H- linac beam. The studies so far have concentrated on simple injection scenarios, at reduced intensity, where longitudinal effects are well separated from transverse. The evolution of the pre-bunched beam during the transition from injection to acceleration has been examined. Results have shown the importance of the detailed linac beam energy distribution. The ability to control the longitudinal emittance of the beam with the fast chopper has been used in other machine studies. This report includes a description of a measurement of the longitudinal coupling impedance of the AGS by the beam transfer function technique which utilized the control of longitudinal emittance provided by bunch-to-bucket injection. Plans for improvements to the chopper equipment are also describe. 6 refs., 4 figs

  14. Modeling of plasma heating with neutral beam injection in T-11 machine

    International Nuclear Information System (INIS)

    Computations of energy balance are presented for a tokamak with hot atom beam injection. Atom ionization, trapping of generated ions and energy transfer to plasma are examined. Energy loss in charge exchange is considered. Relationships are presented between the temperature and the injection power, the plasma density and other parameters. Possibilities are discussed for obtaining a collisionless ion regime

  15. Numerical simulation of high-current ion linear induction accelerator with additional electron beam injection

    International Nuclear Information System (INIS)

    The 2d3v particle-in-cell simulations of the transportation and acceleration of a high-current tubular ion beam through six magnetoinsulated accelerating gaps are presented. Charge and current compensations are carried out by an accompanying electron beam, and also by additionally injected electron beams. The accelerating electric field is enclosed to the first, third and fifth cusps. Its magnitudes are those, that initial kinetic energy of compensating electron beams is little bit higher than a potential barrier of an accelerating field in each cusp, that allows an electron beam to overcome accelerating potential in one cusp. The second, fourth and sixth cusps in which the accelerating field is absent, are used for injection of additional compensating electron beams which replace the electron beam which has 'worked-out' on the previous accelerating gap. The simulations involve solving a complete set of Maxwell's equations with charge-conserving scheme for calculating the current density on a mesh, and relativistic motion equations for charged particles. The possibility of transporting and acceleration of a high-current tubular ion beam in six cusps is shown. It is shown, that distribution function of a high-current ion beam on an output of the accelerator essentially improves due to optimization of parameters of additionally injected electron beams.

  16. Six-dimensional beam matching for axial injection into a cyclotron

    International Nuclear Information System (INIS)

    The general optical structure of a beam line for axial injection into a cyclotron is proposed. It provides the beam matching in the six-dimensional phase space at the entrance of the cyclotron. As an illustration, the hyperboloid and the spiral inflectors are considered

  17. Anomalous slowing of a perpendicularly-injected ion beam in both quasilinear and trapping regimes

    International Nuclear Information System (INIS)

    The anomalous slowing of an ion beam injected perpendicularly to the confining magnetic field of a low β plasma is experimentally verified in the nonlinear stages of the excited lower-hybrid instability. Furthermore, a transition of the main nonlinear mechanism from the quasilinear to the particle trapping regime is demonstrated by varying beam parameters

  18. Development of beam-plasma instability during the injection a low-energy electron beam into the ionospheric plasma

    International Nuclear Information System (INIS)

    Results are presented from an active experiment on the injection of charged particle beams into the ionospheric plasma. The experiment was carried out in 1992 onboard the Intercosmos-25 satellite and the Magion-3 daughter satellite (APEX). A specific feature of this experiment was that both the ion and electron beams were injected upward, in the same direction along the magnetic field. The most interesting results are the excitation of HF and VLF-LF waves and the generation of fast charged particle flows, which were recorded on both satellites

  19. Charge exchange momentum transfer due to ion beam injection in partially ionized plasmas

    International Nuclear Information System (INIS)

    Time responses of a helium plasma to helium gas puffing without and with helium beam injection in a linear plasma device are experimentally investigated. Increase in the neutral density due to gas puffing is suppressed by ion beam injection. The experimental results show that a momentum transport from the ion beam to the puffed neutral particles occurs due to the charge exchange interaction, suggesting that charge exchange momentum transport is one of the processes responsible for the spatial redistribution of neutral atoms in partially ionized plasmas. (author)

  20. Study of pulsed sextupole magnet system for beam injection at UVSOR

    International Nuclear Information System (INIS)

    In order to introduce Pulsed Sextupole Magnet (PSM) injection at UVSOR, we performed simulation of the injection beam, and design of PSM. This PSM was designed to excite a stronger magnetic field by making a gap small. And the simulation was performed using designed PSM. As a result, it revealed that beam injection was sufficiently possible using this PSM at UVSOR, but injected beam must feel magnetic field for several turns by the PSM because of short revolution period of the storage ring. We have measured a magnetic field of this PSM which was completed in this Spring and evaluated the performance of it. A magnetic field remains in a center in PSM because of manufacturing error. So it is necessary that the magnetic field of center is rectified. We considered the method of rectifying the magnetic field of center using a thin ferrite, and confirmed effect of this method. (author)

  1. Amplitude dependent orbit shift and its effect on the beam injection

    International Nuclear Information System (INIS)

    The betatron oscillation amplitude dependent orbit shift was measured at the electron storage ring, NewSUBARU. The result roughly agreed with the theoretical calculation. The effect of this shift on the beam injection is discussed using parameters of NewSUBARU and SPring-8 SR. Generally there exists a better side for the injection, the inner side or the outer side of the ring, which depends on the sign of the shift at the injection septum. In case of the NewSUBARU, the beam is injected from the outer side and the shift is positive. The effective thickness of the septum is reduced by the large oscillation amplitude of the injected beam. However, this effect becomes almost negligible with the running parameter at NewSUBARU, because of the deformation of the phase space contour. On the other hand at SPring-8, the beam is injected from the inner side of the ring while the orbit shift is negative. The injection from the inner side is better. (author)

  2. The injection beam lines of the cryogenic storage ring (CSR)

    International Nuclear Information System (INIS)

    At the Max-Planck-Institute for Nuclear Physics in Heidelberg an electrostatic cryogenic storage ring (CSR) is under construction. The ions for the CSR will be provided by two ion sources with up to 60kV and 300 kV potential, respectively. The layout of the beamlines connecting the ion sources with the CSR is presented. They will be merged using an electrostatic deflector with an opening in the outer electrode, thereby allowing quick switching between the two ion sources. In order to determine the influence of the opening on the beam optics the deflector has been modeled and a modified transport matrix has been derived. An additional beamline element is a detachment region for the neutralization of a negative ion beam by photodetachment. The potential of the detachment region defines the precise energy of the neutral particles. Calculations of the ion beam optics using the MAD X code are described.

  3. Development of laser beam injection system for the Edge Thomson Scattering (ETS) in ITER

    International Nuclear Information System (INIS)

    This paper focuses on the design and development of the laser injection system for the ITER Edge Thomson Scattering system (ETS). The ITER ETS achieves a temporal resolution of 100 Hz by firing two 50 Hz laser beams alternatively. The use of dual lasers enables us to perform the Thomson scattering measurements at a temporal resolution of 50 Hz in case that one of the laser systems stops functioning. A new type of beam combiner was developed to obtain a single beam that is collinear and fixed linearly polarized from two laser beams using a motor-driven rotating half-wave plate. The rotating half-wave plate method does not induce misalignment even if the rotating mechanism malfunctions. The combined beam is relayed from the diagnostic hall to the plasma using mirror optics and is absorbed at the beam dump integrated on the inner blanket. The beam alignment system was designed to direct the laser beam onto the center of the beam dump head. The beam position at the beam dump is monitored by four alignment laser beams which propagate parallel to the diagnostic Nd:YAG laser beam and imaging systems installed outside the diagnostic port

  4. Development of laser beam injection system for the Edge Thomson Scattering (ETS) in ITER

    Science.gov (United States)

    Yatsuka, E.; Hatae, T.; Suitoh, S.; Ohara, M.; Hagita, K.; Inoue, K.; Bassan, M.; Walsh, M.; Itami, K.

    2016-01-01

    This paper focuses on the design and development of the laser injection system for the ITER Edge Thomson Scattering system (ETS). The ITER ETS achieves a temporal resolution of 100 Hz by firing two 50 Hz laser beams alternatively. The use of dual lasers enables us to perform the Thomson scattering measurements at a temporal resolution of 50 Hz in case that one of the laser systems stops functioning. A new type of beam combiner was developed to obtain a single beam that is collinear and fixed linearly polarized from two laser beams using a motor-driven rotating half-wave plate. The rotating half-wave plate method does not induce misalignment even if the rotating mechanism malfunctions. The combined beam is relayed from the diagnostic hall to the plasma using mirror optics and is absorbed at the beam dump integrated on the inner blanket. The beam alignment system was designed to direct the laser beam onto the center of the beam dump head. The beam position at the beam dump is monitored by four alignment laser beams which propagate parallel to the diagnostic Nd:YAG laser beam and imaging systems installed outside the diagnostic port.

  5. Ion transport studies on the PLT tokamak during neutral beam injection

    International Nuclear Information System (INIS)

    Radial transport of ions during co- and counter-neutral beam heating in the PLT tokamak has been studied, using molybdenum and scandium ions as tracer elements. The time evolution of the radial profiles of several ionization stages of both elements, injected by laser blowoff during the neutral beam heating, were measured under three significantly different beam-plasma combinations. No noticeable differences in the radial profiles attributable to the beam direction were observed. However, a given injected amount resulted in considerably larger interior concentrations of the tracer element in the counter-beam heating cases, suggesting larger penetration of the plasma periphery. Computer simulation with the MIST code suggests a net inward drift of the order 103 cm/sec superposed to a diffusion coefficient of the order 104 cm2/sec for both scandium and molybdenum ions. Injection of larger amounts of the tracer element, sufficient to cause measurable central electron temperature changes, resulted in dramatic changes in ion-state distributions, making some appear peaked in the center while others disappeared. This effect could be produced with both co- and counter-beam heating, but with lesser amounts in the latter case. It is interpreted as rearrangement of the ionization balance, rather than any preferential accumulation of the injected element

  6. The TFTR 40 MW neutral beam injection system and DT operations

    International Nuclear Information System (INIS)

    Since December 1993, TFTR has performed DT experiments using tritium fuel provided mainly by neutral beam injection. Significant alpha particle populations and reactor-like conditions have been achieved at the plasma core, and fusion output power has risen to a record 10.7 MW using a record 40 MW NB heating. Tritium neutral beams have injected into over 480 DT plasmas and greater than 500 kCi have been processed through the neutral beam gas, cryo, and vacuum systems. Beam tritium injections, as well as tritium feedstock delivery and disposal, have now become part of routine operations. Shot reliability with tritium is about 90% and is comparable to deuterium shot reliability. This paper describes the neutral beam DT experience including the preparations, modifications, and operating techniques that led to this high level of success, as well as the critical differences in beam operations encountered during DT operations. Also, the neutral beam maintenance and repair history during DT operations, the corrective actions taken, and procedures developed for handling tritium contaminated components are discussed in the context of supporting a continuous DT program

  7. Injection locking of a semiconductor laser to a multi-frequency reference beam

    CERN Document Server

    Yang, T; Giudici, Massimo; Wilkowski, David

    2013-01-01

    Injection locking is a well known and commonly used method for coherent light amplification. Usually injection locking is done with a single-frequency seeding beam. In this work we show that injection locking may also be achieved in the case of multi-frequency seeding beam when slave laser provides sufficient frequency filtering. One relevant parameter turns out to be the frequency detuning between the free running slave laser and each injected frequency component. Stable selective locking to a set of three components separated of $1.2\\,$GHz is obtained for (positive) detuning values between zero and $1.5\\,$GHz depending on seeding power (ranging from 10 to 150 microwatt). This result suggests that, using distinct slave lasers for each line, a set of mutually coherent narrow-linewidth high-power radiation modes can be obtained.

  8. Computer simulation of high current uranium beams for the injection beam line of the UNILAC

    International Nuclear Information System (INIS)

    In an attempt to generate an ion beam with high current and high brightness for the design ion, the computer code KOBRA3-INP has been used to evaluate the extraction system, the DC post-acceleration system as well as the quadrupole transport beam line, and to study the behavior of the ion beam in the combined system. (orig.)

  9. Dispersion Matching of a Space Charge dominated Beam at Injection into the CERN PS Booster

    CERN Document Server

    Hanke, Klaus; Scrivens, Richard

    2005-01-01

    In order to match the dispersion at injection into the CERN PS Booster, the optics of the injection line was simulated using two different codes (MAD and TRACE). The simulations were benchmarked versus experimental results. The model of the line was then used to re-match the dispersion. Experimental results are presented for different optics of the line. Measurements with varying beam current show the independence of the measured quantity of space-charge effects.

  10. Plasma heating simulation in the T-11 device on the neutral atom beam injection

    International Nuclear Information System (INIS)

    Calculations of the energy balance in the tokamak with injection of hot atom beams are carried out. Considered are atom ionization and capture of the produced ones as well as the transmission of energy to plasma. Energy losses on recharging are taken into account. Given are temperature dependencies on injection power, plasma density and other parameters. A possibility to obtain collisionless regime by ions is described

  11. Comparison of Heating Efficiency Between Co and Counter Neutral Beam injection in Large Helical Device

    Science.gov (United States)

    Ikeda, Katsunori; Kaneko, Osamu; Osakabe, Masaki; Takeiri, Yasuhiko; Tsumori, Katsuyoshi; Oka, Yoshihide; Murakami, Sadayoshi; Narihara, Kazumichi; Asano, Eiji E.; Kawamoto, Toshikazu; LHD Experiment Groups Team

    2001-10-01

    In the Large Helical Device, tangential neutral beam injection (NBI) is adopted in order to avoid that the fast ions are directly trapped in helical ripples. Then effective heating is realized by negative ion based high energy tangential NBI systems in Large Helical Device, two beam lines ware arranged counter -injection and the other one was arranged co-injection. However, it is predicted that the absorption efficiency of a NBI heating is also influenced by troidal drift motion of injected beam particle in weak magnetic field (Bt < 1T) operations such as high beta experiment. And also plasmas must be build up by using tangential NBI heating alone from the magnetic field strength Bt 0.5T to 1.5T, since heating by electron cyclotron heating can not be performed. So, the efficiency of co and counter NBI heating is an important issue for generating high beta plasma. According to experiment results, either of co and counter NBI was able to heat plasma efficiently in Bt=0.75T. Enhancement factors of energy confinement time without considering direct drift loss is almost the same in these plasmas. However, there is a difference in build up time of plasma by co and counter. There are no big difference in an electron temperature profile of co and counter heating as low as Bt=0.75 although the beam absorption profile may be different between co and counter injection.

  12. Beam emittance growth in a proton storage ring employing charge exchange injection

    International Nuclear Information System (INIS)

    Recently, it has been shown that very large currents can be accumulated in medium energy proton storage rings by multiturn injection of an H- beam through a charge stripping medium. Since the particles are injected continuously into the same phase space, it is possible to increase the circulating beam brightness with respect to that of the incoming beam by a large factor. The stored protons pass repeatedly through the stripper, however, so that this phase space is gradually enlarged by scattering. The dependence of the circulating beam phase space (emittance) growth rate on the nature of the scattering process and on where it occurs in the storage ring matrix is considered. Since the motivation for this work arose in connection with the design of the proposed high-current storage ring at LAMPF, the results are focused on the specific parameters of that device. (U.S.)

  13. Transverse emittance blow-up from beam injection errors in synchrotrons with nonlinear feedback systems

    International Nuclear Information System (INIS)

    The problem of transverse emittance blow-up from beam injection errors in synchrotrons with nonlinear feedback systems is considered. The relative emittance growth is calculated for linear and nonlinear feedback transfer functions. Effects of an increase of the damping decrement of the beam coherent oscillations and of a decrease of the coherent transverse amplitude spread of different bunches in case of the damper with positive cubic term in the feedback transfer function are discussed

  14. Measurement of H- beam emittance in axial injection channel of DC-72 cyclotron

    International Nuclear Information System (INIS)

    A method of measuring the ion beam transversal emittance in the axial injection channel of DC-72 cyclotron is given. It is based on the gradient method using the standard rotating wire scanner for measurement of the transversal ion beam dimensions. This method was worked out for ion beam currents up to 1000 μA and allows one to reconstruct emittance with an accuracy about 30%. The method takes into account the ion beam self-charge, which is essential. It is not always a success to obtain an axial-symmetric ion beam in experiments. Therefore, a new experimental data processing method of measuring the transversal emittance for a non-axial-symmetric ion beam was suggested. The formulae for determination of the RMS dispersions of the ion beam dimensions in the rotation coordinate system by signals from the scanner wire are given. The measurements of the RMS emittances εx,y were carried out in the test stand of the injection channel of DC-72 cyclotron with the H- ion beam current of 180 μA and kinetic energy of ions of 16.82 keV. The results of the experimental data processing are adduced

  15. Power and particle balance during neutral beam injection in TFTR

    International Nuclear Information System (INIS)

    Detailed boundary plasma measurements on TFTR have been made during a NBI power scan in the range Ptot = 1MW--20MW in the L-mode regime. The behavior of the plasma density left-angle ne right-angle, radiated power Prad, carbon and deuterium fluxes ΓC, ΓD, and Ζeff can be summarized as, left-angle ne right-angle ∝ Ptot1/2, Prad, ΓC, ΓD ∝ Ptot, and Ζeff ∼ constant. It is shown that central fuelling by the neutral beams plays a minor role in the particle balance of the discharge. More important is the NBI role in the power balance. The TFTR data during NBI originate primarily at the graphite limiter

  16. Design of neutral beam injection power supplies for ITER

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Kazuhiro; Okumura, Yoshikazu [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; Higa, Osamu; Kawashima, Syuichi [Toshiba Corp., Kawasaki, Kanagawa (Japan); Ono, Youichi; Tanaka, Masanobu [Hitachi Ltd., Tokyo (Japan)

    2000-03-01

    Design study on a power supply system for the ITER neutral beam injector(NBI) has been performed. Circuits of converter/inverter system and other components of the acceleration power supply whose capacity is 1 MV, 45 A have been designed in detail. Performance of the negative ion production power supplies such as an arc and an extraction power supplies was investigated using the EMTDC code. It was confirmed that ripples of 0.34%p-p for the extraction power supply and 1.7%p-p for the arc power supply are small enough. It was also confirmed that an energy input to a negative ion generator from the arc power supply at an arcing can be suppressed smaller than 8 J. The extraction power supply was designed to suppress the energy input lower than 13 J at the breakdown in the extractor. These performances satisfy the required specification of the power supply system. (author)

  17. An elegant impulser developed for flat beam injection

    International Nuclear Information System (INIS)

    The following report describes the design, construction, and checkout of a high-voltage (HV) impulser built for the heavy ion fusion (HIF) project [1]. The purpose of this impulser is to provide an adjustable diode voltage source of sufficient quality and level to allow the optimization of beam transport and accelerator sections of HIF [2, 3]. An elegant, low-impedance, high-energy storage capacitor circuit has been selected for this application. Circuit parameters of the retrofit to the diode region [4] have been included to provide the controlled rise time. The critical part of this circuit that is common to all candidates is the impedance matching component. The following report provides a description of the implemented circuit, the basic circuit variables for wave shaping, screening techniques revealing the weakest circuit component, and the resulting output of the injector

  18. Shielding considerations for neutral-beam injection systems

    International Nuclear Information System (INIS)

    Results of a study on the geometry of an FED-A Neutral Beam Injector beamline duct shield are presented. Also included is a calculation of dose rates, as a function of time, from an activated NBI. The shielding investigations consisted of varying the parameters of the geometry and transporting particles through it using the MCNP Monte-Carlo code. The dose rates were calculated by the ACDOS3 code using realistic MCNP results. A final-to-incident flux ratio of 6.5 x 10-7 can be achieved through the use of a 65.5 cm reentry duct. This is for a realistic source and pure water shielding material. The activated NBI produced a dose rate of 15.9 mrem/hr two and a half days after shutdown of the reactor

  19. Buildup of electrons with hot electron beam injection into a homogeneous magnetic field

    International Nuclear Information System (INIS)

    The injection of the monoenergetic beam of electrons into the vacuum drift channel under the conditions when the beam current exceeds a certain threshold value involves a virtual cathode creation. The process of virtual cathode creation leads to an exchange of one-fluid movement of beam particles to three-fluid one corresponding to incident, reflected and passed through anticathode beam particles. For the monoenergetic beam case when the velocity spread Δvdr (vdr is the beam drift velocity), the beam instability was predicted in theory and was observed in experiment. Meanwhile, the injection in the drift space of the 'hot' beam having finite spread in velocities may be accompanied not only by the reflection of particles if their velocity v1/2 (where φ is the electrostatic potential dip value, e and m are the electron charge and mass, respectively), but also the mutual Coulomb scattering of incident and reflected electrons. The scattering process leads in its turn to appearance of viscosity forces and to trapping of a part of beam electrons into the effective potential well formed by electrostatic potential dip and the viscous force potential. The interaction of travelling and trapped particles may occur even at the stage preceding the virtual electrode formation and it may influence the process of its appearance and also the current flow through the drift space. In this report there are described the experimental results on accumulation of electrons when electron beam propagates in vacuum and has a large spread in particle velocities Δvdr in the homogeneous longitudinal magnetic field when ωpeHe where ωpe is the electron Langmuir frequency of beam electrons, ωHe is the electron cyclotron frequency. (author) 6 refs., 2 figs

  20. Behavior of high-pressure gasses injected to vacuum through a fast solenoid valve for supersonic cluster beam injection

    International Nuclear Information System (INIS)

    The supersonic cluster beam (SSCB) injection method is being developed as a new fueling method for the Large Helical Devise (LHD) experiment. As a first step, cluster formation at a room temperature has been investigated for various gasses using a fast solenoid valve for SSCB. Rayleigh scattering of laser light by the cluster is measured by a fast charge coupled device (CCD) camera. In the case of methane, nitrogen, and argon, clear scattering signals are observed at the high backing pressure of more than 3 - 4 MPa. In the case of hydrogen, helium, and neon, on the other hand, no scattering signal is detected at 7 MPa. (author)

  1. Accelerator System Design, Injection, Extraction and Beam-Material Interaction: Working Group C Summary Report

    CERN Document Server

    Mokhov, N V

    2014-01-01

    The performance of high beam power accelerators is strongly dependent on appropriate injection, acceleration and extraction system designs as well as on the way interactions of the beam with machine components are handled. The experience of the previous ICFA High -Brightness Beam workshops has proven that it is quite beneficial to combine analyses and discussion of these issues in one group. A broad range of topics was presented and discussed at the Working Group C sessions at the HB2012 Workshop. Highlights from the talks, outstanding issues along with plans and proposals for future work are briefly described in this report.

  2. Assessment of the plasma start-up in Wendelstein 7-X with neutral beam injection

    International Nuclear Information System (INIS)

    Plasma start-up by neutral beam injection was investigated for stellarators. A zero-dimensional collisional model was extended to evaluate the temporal evolution of the plasma start-up in a confining toroidal magnetic field. Inclusion of different beam energy components indicated a substantial effect due to the energy dependence of beam–gas collisions. Additional collision processes and particle equations were considered to simulate the plasma start-up in helium–hydrogen mixtures. The isotope effect between operation with hydrogen and deuterium beams was also investigated. As a major objective the conditions necessary for a plasma start-up with neutral beams in W7-X have been examined. The assessed beam configuration in W7-X was found not to allow plasma start-up by neutral beam injection alone. The model has been validated for experimental data from W7-AS and Large Helical Device. Quantitative predictions of this study show that the ratio of the beam–plasma interaction length and the plasma volume is an essential quantity for the successful plasma start-up with neutral beams. (paper)

  3. Acceleration of energetic particles by whistler waves in active space experiment with charged particle beams injection

    Czech Academy of Sciences Publication Activity Database

    Baranets, N.; Ruzhin, Y.; Erokhin, N.; Afonin, V.; Vojta, Jaroslav; Šmilauer, Jan; Kudela, K.; Matišin, J.; Ciobanu, M.

    2012-01-01

    Roč. 49, č. 5 (2012), s. 859-871. ISSN 0273-1177 Institutional support: RVO:68378289 Keywords : Electron beam injection * Whistler waves * Wave-particle interaction Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.183, year: 2012 http://www.sciencedirect.com/science/article/pii/S0273117711007976

  4. Direct energy conversion and neutral beam injection for catalyzed D and D-3He tokamak reactors

    International Nuclear Information System (INIS)

    The calculated performance of single stage and Venetian blind direct energy converters for Catalyzed D and D-3He Tokamak reactors are discussed. Preliminary results on He pumping are outlined. The efficiency of D and T neutral beam injection is reviewed

  5. Drift distance survey in direct plasma injection scheme for high current beam production

    International Nuclear Information System (INIS)

    In a laser ion source, plasma drift distance is one of the most important design parameters. Ion current density and beam pulse width are defined by plasma drift distance between a laser target and beam extraction position. In direct plasma injection scheme, which uses a laser ion source and a radio frequency quadrupole linac, we can apply relatively higher electric field at beam extraction due to the unique shape of a positively biased electrode. However, when we aim at very high current acceleration such as several tens of milliamperes, we observed mismatched beam extraction conditions. We tested three different ion current at ion extraction region by changing plasma drift distance to study better extraction condition. In this experiment, C6+ beam was accelerated. We confirmed that matching condition can be improved by controlling plasma drift distance.

  6. Beam injection and accumulation method in storage rings for heavy ion fusion

    International Nuclear Information System (INIS)

    A combination of multiturn injection and rf stacking is proposed as an efficient beam injection method in storage rings for heavy ion fusion. Five turn injection in each transverse phase space and four rf stackings give a total of 100 stacking turns. This represents a compromise between the tolerable emittances and momentum spread in the ring. Space charge limitations and coherent beam instabilities are investigated. The most severe limit is found to be the transverse coherent instability, but this can be controlled by the use of sextupole and octupole magnetic fields. Assuming a charge exchange cross section of 1 x 10-15 cm2, the e-folding life time is estimated at 180 ms, while the stacking time is 40 ms

  7. Diffraction effect of the injected beam in axisymmetrical structural CO2 laser

    Science.gov (United States)

    Xu, Yonggen; Wang, Shijian; Fan, Qunchao

    2012-07-01

    Diffraction effect of the injected beam in axisymmetrical structural CO2 laser is studied based on the injection-locking principle. The light intensity of the injected beam at the plane where the holophotes lie is derived according to the Huygens-Fresnel diffraction integral equation. And then the main parameters which influence the diffraction light intensity are given. The calculated results indicate that the first-order diffraction signal will play an important role in the phase-locking when the zero-order diffraction cannot reach the folded cavities. The numerical examples are given to confirm the correctness of the results, and the comparisons between the theoretical and the experimental results are illustrated.

  8. Operating characteristics of a new ion source for KSTAR neutral beam injection system.

    Science.gov (United States)

    Kim, Tae-Seong; Jeong, Seung Ho; Chang, Doo-Hee; Lee, Kwang Won; In, Sang-Ryul

    2014-02-01

    A new positive ion source for the Korea Superconducting Tokamak Advanced Research neutral beam injection (KSTAR NBI-1) system was designed, fabricated, and assembled in 2011. The characteristics of the arc discharge and beam extraction were investigated using hydrogen and helium gas to find the optimum operating parameters of the arc power, filament voltage, gas pressure, extracting voltage, accelerating voltage, and decelerating voltage at the neutral beam test stand at the Korea Atomic Energy Research Institute in 2012. Based on the optimum operating condition, the new ion source was then conditioned, and performance tests were primarily finished. The accelerator system with enlarged apertures can extract a maximum 65 A ion beam with a beam energy of 100 keV. The arc efficiency and optimum beam perveance, at which the beam divergence is at a minimum, are estimated to be 1.0 A/kW and 2.5 uP, respectively. The beam extraction tests show that the design goal of delivering a 2 MW deuterium neutral beam into the KSTAR Tokamak plasma is achievable. PMID:24593588

  9. Computer study of an energy recovery system for the Tore-Supra neutral beam injection lines

    International Nuclear Information System (INIS)

    The prototype of an Energy Recovery System (ERS) has been designed for the Tore-Supra neutral beam injection lines (100 kV, 40 A deuterium beams). Our study, based on computer calculations using a 2-D charged particle trajectory program, consisted mainly in the optimisation of the components of the ERS, but it has been extended in order to draw general conclusions on some problems that might be encountered and to derive scaling laws for the suppression voltage determination. In our system, the power saving can be as large as 1 MW per injection line, i.e. about 25 % of the total power that would be spent without energy recovery. The recovery on higher energy beams has also been investigated; the power gain would be even larger in this case

  10. Numerical Simulation of Non-Inductive Current Driven Scenario in EAST Using Neutral Beam Injection

    Science.gov (United States)

    Li, Hao; Wu, Bin; Wang, Jinfang; Wang, Ji; Hu, Chundong

    2015-01-01

    For achieving the scientific mission of long pulse and high performance operation, experimental advanced superconducting tokamak (EAST) applies fully superconducting magnet technology and is equiped with high power auxiliary heating system. Besides RF (Radio Frequency) wave heating, neutral beam injection (NBI) is an effective heating and current drive method in fusion research. NBCD (Neutral Beam Current Drive) as a viable non-inductive current drive source plays an important role in quasi-steady state operating scenario for tokamak. The non-inductive current driven scenario in EAST only by NBI is predicted using the TSC/NUBEAM code. At the condition of low plasma current and moderate plasma density, neutral beam injection heats the plasma effectively and NBCD plus bootstrap current accounts for a large proportion among the total plasma current for the flattop time.

  11. Comparison of ELM-Filament Mitigation Between Supersonic Molecular Beam Injection and Pellet Injection on HL-2A

    Science.gov (United States)

    Nie, Lin; Cheng, Jun; Xu, Hongbing; Huang, Yuan; Yan, Longwen; Ding, Xuantong; Xu, Min; Xu, Yuhong; Yao, Lianghua; Feng, Beibin; Zhu, Genliang; Liu, Wandong; Dong, Jiaqi; Yu, Deliang; Zhong, Wulv; Gao, Jinming; Chen, Chengyuan; Yang, Qingwei; Duan, Xuru

    2016-02-01

    On HL-2A, two different injections (supersonic molecular beam injection (SMBI) and pellet injection (PI)) are used to mitigate edge localized mode (ELM)-filament convective transport. The changes of their characteristics are studied in this paper. A high spatiotemporal resolution probe shows there are many similar phenomena, and the filament density amplitude and radial velocity are both suppressed. Our statistical results indicate that: the velocity suppression comes from the decrease of filament density and temperature; the transient particle and heat fluxes drop strongly; and long-range correlation along a magnetic flux surface also decreases, when the electron-ion collisionality increases significantly, which may have a role on the filament parallel current during ELM mitigation. supported by National Natural Science Foundation of China (Nos. 11075046, 10975049, 11375054, 11275060), the National Magnetic Confinement Fusion Science Program of China (Nos. 2013GB112008, 2013GB107000, 2013GB104002, 2014GB107000, 2014GB108000), and the China-Korean Joint Research Program (No. 2012DFG02230)

  12. Neutralization of ion beam by means of transverse injection of electrons

    Science.gov (United States)

    Baitin, A. V.; Serebrennikov, K. S.; Sionov, A. B.

    1997-01-01

    Electron beam transverse injection into a region of a positive ion beam propagating between two conducting plates is considered. This problem is important for ion beam propagation in the implanter tracts and for construction of ion beam focusing elements. After the transition stage the formation of different stationary ion-beam plasma states is possible, with electrons being accelerated or decelerated while moving from the wall up to the center of the ion beam. The dependence of the final state on the parameters of the system is obtained. The regime with deceleration is characterized by negative total space charge and can be used for focusing of the ion beam. Temporary evolution of the neutralization process and realization of these stationary states is studied by means of one-dimensional particle-in-cell code simulation. The dynamics of the process in the case of absence of the stationary state and such non-stationary phenomena like sheath and virtual cathode are studied, too. This process comes to a high degree of neutralization due to the electrons being captured by the ion beam space charge potential.

  13. Suppression of stored beam oscillation at injection in the SPring-8 storage ring

    International Nuclear Information System (INIS)

    In the SPring-8 storage ring, when the injection bump orbit is not closed perfectly at the beam injection, the horizontal stored beam oscillation of the amplitude more than 0.5 mm (r.m.s.) is excited. Now, the averaged oscillation amplitude has successfully been suppressed to the level of less than 0.15 mm (r.m.s.) by applying a counter kick to the residual oscillation with a pulse width of 500 ns. To confirm the suppression effect, we observed the turn-by-turn photon beam profile at the diagnostics beamline with the insertion device. The light axis oscillation was significantly suppressed down to less than 4 μrad from more than 30μrad by applying a counter kick at 3rd turn after injection. Without the kicker correction, it took about 80 turns to reduce the oscillation, which was determined by the damping time with the bunch by bunch feedback system. In the SPring-8 user operation, in addition to the effect of providing stable photon beam, we succeeded in not only shortening the effective damping time but also filling a single high current bunch up to 5 mA to any bucket address. (author)

  14. Efficient, radiation-hardened, 800-keV neutral beam injection system

    International Nuclear Information System (INIS)

    Recent advances and new concepts in negative ion generation, transport, acceleration, and neutrailzation make it appear likely that an efficient, radiation-hardened neutral beam injection system could be developed in time for the proposed FED-A tokamak. These new developments include the operation of steady-state H- ion sources at over 5 A per meter of source length, the concept of using strong-focussing electrostatic structures for low-gradient dc acceleration of high-current sheet beams of negative ions and the transport of these beams around corners, and the development of powerful oxygen-iodine chemical lasers which will make possible the efficient conversion of the negative ions to neutrals using a photodetachment scheme in which the ion beam passes through the laser cavity

  15. Estimates of HE-LHC beam parameters at different injection energies

    Energy Technology Data Exchange (ETDEWEB)

    Sen, Tanaji; /Fermilab

    2010-11-01

    A future upgrade to the LHC envisions increasing the top energy to 16.5 TeV and upgrading the injectors. There are two proposals to replace the SPS as the injector to the LHC. One calls for a superconducting ring in the SPS tunnel while the other calls for an injector (LER) in the LHC tunnel. In both scenarios, the injection energy to the LHC will increase. In this note we look at some of the consequences of increased injection energy to the beam dynamics in the LHC.

  16. Early Beam Injection Scheme for the Fermilab Booster: A Path for Intensity Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Bhat, C. M. [Fermilab

    2015-10-28

    Over the past decade, Fermilab has focused efforts on the intensity frontier physics and is committed to increase the average beam power delivered to the neutrino and muon programs substantially. Many upgrades to the existing injector accelerators, namely, the current 400 MeV LINAC and the Booster, are in progress under the Proton Improvement Plan (PIP). Proton Improvement Plan-II (PIP-II) proposes to replace the existing 400 MeV LINAC by a new 800 MeV LINAC, as an injector to the Booster which will increase Booster output power by nearly a factor of two from the PIP design value by the end of its completion. In any case, the Fermilab Booster is going to play a very significant role for nearly next two decades. In this context, I have developed and investigated a new beam injection scheme called "early injection scheme" (EIS) for the Booster with the goal to significantly increase the beam intensity output from the Booster thereby increasing the beam power to the HEP experiments even before PIP-II era. The scheme, if implemented, will also help improve the slip-stacking efficiency in the MI/RR. Here I present results from recent simulations, beam studies, current status and future plans for the new scheme.

  17. R & D on Beam Injection and Bunching Schemes in the Fermilab Booster

    Energy Technology Data Exchange (ETDEWEB)

    Bhat, C. M. [Fermilab

    2016-01-01

    Fermilab is committed to upgrade its accelerator complex to support HEP experiments at the intensity frontier. The ongoing Proton Improvement Plan (PIP) enables us to reach 700 kW beam power on the NuMI neutrino targets. By the end of the next decade, the current 400 MeV normal conducting LINAC will be replaced by an 800 MeV superconducting LINAC (PIP-II) with an increased beam power >50% of the PIP design goal. Both in PIP and PIP-II era, the existing Booster is going to play a very significant role, at least for next two decades. In the meanwhile, we have recently developed an innovative beam injection and bunching scheme for the Booster called "early injection scheme" that continues to use the existing 400 MeV LINAC and implemented into operation. This scheme has the potential to increase the Booster beam intensity by >40% from the PIP design goal. Some benefits from the scheme have already been seen. In this paper, I will describe the basic principle of the scheme, results from recent beam experiments, our experience with the new scheme in operation, current status, issues and future plans. This scheme fits well with the current and future intensity upgrade programs at Fermilab.

  18. Characteristics of the injected ion beam in the ECR charge breeder 1+ -> n+

    CERN Document Server

    Lamy, T; Chauvin, N; Curdy, Jean Claude; Geller, R; Sortais, P; Leroy, R; Lieuvin, M; Villari, A C C

    1999-01-01

    Different ion species (rare gases, alkali, metallic) have been injected on the axis of the MINIMAFIOS - 10 GHz - Electron Cyclotron Resonance Ion Source which is the basics of the 1+ -> n+ method, special attention have been paid to the optics of the incoming beam for the validation of the 1+ -> n+ method for the SPIRAL project (Radioactive Ion Beam facility). The capture of the incoming ion beam by the ECR plasma depends, first, on the relative energy of the incoming ions with respect to the average ion energy in the plasma, and secondly, on the optics of the injection line. The efficiency of the process when varying the potential V n+ of the MINIMAFIOS source with respect to the potential V 1+ applied to the 1+ source (DV=V n+ -V 1+ ) is an image of the energy dispersion of the 1+ beam. 1+ -> n+ spectra efficiencies, DV efficiency dependence for the most efficient charge state obtained, and measured primary beam emittances are given for the Ar, Rb, Pb, Cr. Highest efficiencies obtained are respectively Ar1+...

  19. An RF driven H- source and a low energy beam injection system for RFQ operation

    International Nuclear Information System (INIS)

    An RF driven H- source has been developed at LBL for use in the Superconducting Super Collider (SSC). To date, an H- current of ∼40 mA can be obtained from a 5.6-cm-diam aperture with the source operated at a pressure of about 12 m Torr and 50 kW of RF power. In order to match the accelerated H- beam into the SSC RFQ, a low-energy H- injection system has been designed. This injector produces an outgoing H- beam free of electron contamination, with small radius, large convergent angle and small projectional emittance

  20. Beam imaging in the injection line of the INFN-LNS superconducting cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Nicolosi, Dario, E-mail: dario.nicolosi@lns.infn.it; Cosentino, Luigi; Mascali, David; Pappalardo, Alfio; Castro, Maurizio; Celona, Luigi; Marchetta, Carmelo; Marletta, Salvatore; Maugeri, Antonio; Rifuggiato, Danilo; Seminara, Angelo; Gammino, Santo [INFN-Laboratori Nazionali del Sud, Via S. Sofia 62, 95123 Catania (Italy)

    2016-02-15

    A cheap and efficient diagnostic system for beam monitoring has been recently developed at INFN-LNS in Catania. It consists of a high sensitivity CCD camera detecting the light produced by an ion beam hitting the surface of a scintillating screen and a frame grabber for image acquisition. A scintillating screen, developed at INFN-LNS and consisting of a 2 μm BaF{sub 2} layer evaporated on an aluminium plate, has been tested by using {sup 20}Ne and {sup 40}Ar beams in the keV energy range. The CAESAR ECR ion source has been used for investigating the influence of the frequency and magnetic field tuning effects, the impact of the microwave injected power, and of the focusing solenoids along the low energy beam transport on the beam shape and current. These tests will allow to better understand the interplay between the plasma and beam dynamics and, moreover, to improve the transport efficiency along the low energy beam line and the matching with the superconducting cyclotron, particularly relevant in view of the expected upgrade of the machine.

  1. Neutral beam injection heating on field-reversed configuration plasma decompressed through axial translation

    International Nuclear Information System (INIS)

    The power deposition of neutral beam injection (NBI) on translated field-reversed configuration (FRC) plasma has been investigated. A certain level of electron heating effect was observed in the slowly decaying phase of the decompressed FRC, leading to a hollow electron temperature profile. Numerical calculation of beam trajectories has shown that about 50% of the injected NB power is absorbed by the plasma electron inside the separatrix with a hollow deposition profile similar to the observed electron temperature profile. The estimated absorbed NB power of 120 kW will be enough to bring the change in electron temperature, since the electron conduction and radiation loss was estimated to be ∼100 kW

  2. Density peaking in the JFT-2M tokamak plasma with counter neutral beam injection

    International Nuclear Information System (INIS)

    A significant particle pinch and reduction of the effective thermal diffusivity are observed after switching the neutral beam direction from co- to counter- injection in the JFT-2M tokamak. A time delay in the occurrence of density peaking to that of plasma rotation is found. This shows that the particle pinch is related to the profile of the electric field as determined by the plasma rotation profile. The measured particle flux shows qualitative agreement with the theoretically-predicted inward pinch. (author)

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

    International Nuclear Information System (INIS)

    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.

  4. Toroidal plasma rotation in the PLT tokamak with neutral-beam injection

    International Nuclear Information System (INIS)

    Toroidal plasma rotation in the Princeton Large Torus, PLT, has been measured for various plasma and neutral beam injection conditions. Measurements of the plasma rotational velocities were made from Doppler shifts of appropriate spectral lines and include data from both hydrogen and deuterium beams and co- and counter-injection at several electron densities. Without injection, a small but consistent toroidal rotation exists in a direction opposite to the plasma current (counter-direction) in the plasma center but parallel to the current (co-direction) in the plasma periphery. Using these measured velocities and the plasma density and temperature gradients, radial electron fields can be determined from theory, giving E/sub r / approx. = 40 V/cm near the plasma center and E/sub r/ approx. = 10 V/cm near the plasma edge. Insertion of a local, 2.5 percent magnetic well produced no observable effect on the beam driven rotation. Modeling of the time evolution and radial distribution of the rotation allows one to deduce an effective viscosity of the order of (1 to 5) x 104 cm2/sec

  5. ELM mitigation by means of supersonic molecular beam and pellet injection on the EAST superconducting tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Hu, J.S., E-mail: hujs@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, Hefei 230031 (China); Sun, Z.; Li, C.Z.; Zhen, X.W.; Li, J.G.; Guo, H.Y.; Li, J.H.; Wang, L.; Gan, K.F.; Chen, Y.; Ren, J.; Zuo, G.Z.; Yao, X.J.; Hu, L.Q.; Gong, X.Z.; Wan, B.N. [Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, Hefei 230031 (China); Zou, X.L. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Mansfield, D.K. [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); Liang, Y.F. [Forschungszentrum Jülich GmbH, Association EURATOM-FZ Jülich (Germany); Vinyar, I. [PELIN LLC, Saint Petersburg (Russian Federation)

    2015-08-15

    In this paper, we will present experimental results from EAST on the mitigation of edge localized modes (ELMs) using recently developed deuterium/lithium pellet injections as well as supersonic molecular beam injections (SMBI). Using a Laval nozzle, ELM mitigation with SMBI has been demonstrated in EAST in quasi-steady state. Using a D{sub 2} pellet injector, a giant ELM appears followed by a burst of high frequency ELMs at ∼300 Hz with duration of a few tens of milliseconds. Furthermore, for the first time, a novel technology using a simple rotating impeller to inject sub-millimeter size lithium (Li) granules at speeds of a few tens of meters per second was successfully used to pace ELMs. These experiments indicate that, on EAST, several technologies can contribute to the database supporting ELMs control in future fusion devices, such as ITER.

  6. ELM mitigation by means of supersonic molecular beam and pellet injection on the EAST superconducting tokamak

    International Nuclear Information System (INIS)

    In this paper, we will present experimental results from EAST on the mitigation of edge localized modes (ELMs) using recently developed deuterium/lithium pellet injections as well as supersonic molecular beam injections (SMBI). Using a Laval nozzle, ELM mitigation with SMBI has been demonstrated in EAST in quasi-steady state. Using a D2 pellet injector, a giant ELM appears followed by a burst of high frequency ELMs at ∼300 Hz with duration of a few tens of milliseconds. Furthermore, for the first time, a novel technology using a simple rotating impeller to inject sub-millimeter size lithium (Li) granules at speeds of a few tens of meters per second was successfully used to pace ELMs. These experiments indicate that, on EAST, several technologies can contribute to the database supporting ELMs control in future fusion devices, such as ITER

  7. Performance of magnetically-injected-plasma opening switches on the particle beam fusion accelerator 2

    International Nuclear Information System (INIS)

    Plasma opening switch (POS) experiments have been performed on the PBFA II ion beam accelerator to develop a switch which will provide voltage and power gain to an applied-B lithium ion diode. These experiments have successfully coupled power to electron and ion beam diodes using a Magnetically-Injected-Plasma (MIP) POS. Carbon plasma with electron densities of 1 x 1012 to 2 x 1013 /cm3 have been injected from the anode into the 8 cm gap of the 20-ohm Magnetically-Insulated-Transmission Line (MITL) of PBFA II along a Br,z magnetic field. The MIP switch uses the inertia of the plasma to keep the switch closed and the magnetic pressure of Bθ from the conduction current to open the switch. The configuration of the injecting magnetic field and the plasma source has a significant effect on the efficiency of coupling power to high impedance loads. Plasma near the center of the injecting magnetic field limits the opening impedance of the switch and subsequently the power delivered to the load. The axial location of the switch with respect to the load has also been identified as a critical parameter in increasing the coupling efficiency. A length of 10 to 20 cm of MITL between the POS and the load has increased the power delivered to the load. Data on switch performance with high impedance loads and factors which improved performance are discussed

  8. Excitation of HF and ULF-VLF waves during charged particle beams injection in active space experiment

    International Nuclear Information System (INIS)

    Results of active space experiment with simultaneous injection of electron and xenon ion beams from the Interkosmos-25 (IK-25) satellite are presented. A specific feature of this experiment was that charged particles were injected in the same direction along the magnetic field lines and the particle beams simultaneously injected into the ionospheric plasma were therefore nested in one another. Results of the beam-plasma interaction for this configuration were registered by the double satellite system consisting of IK-25 station and Magion-3 subsatellite. (author)

  9. Ionization, stopping, and thermalization of hydrogen and boron beams injected in fusion plasmas

    Science.gov (United States)

    Lifschitz, Agustín F.; Farengo, Ricardo; Arista, Nestor R.

    2000-07-01

    The ionization, stopping, and thermalization of hydrogen and boron beams, injected, respectively, in boron and hydrogen plasmas, is studied. The evolution of the charge state populations of the neutral beams is described considering the various ionization, excitation, and charge exchange channels. The interaction of the beam with the plasma is described in terms of the Fokker-Planck equation, which is numerically solved to show in detail the evolution of the beam until final thermalization is reached. Beam energies of 640 keV/u (maximum of the cross section for the p-B11 fusion reaction) and 200 keV/u, and various plasma temperatures are considered. It is seen that, due to an important perpendicular-diffusion effect, high energy beams reach effective peak temperatures which are much higher than the plasma temperature, before equilibrium is established. The fraction of fusioned particles is also calculated. Some implications of interest for recently proposed p-B11 fusion reactor systems are drawn out.

  10. Early Beam Injection Scheme for the Fermilab Booster: A Path for Intensity Upgrade

    CERN Document Server

    Bhat, C M

    2015-01-01

    Over the past decade, Fermilab has focused efforts on the intensity frontier physics and is committed to increase the average beam power delivered to the neutrino and muon programs substantially. Many upgrades to the existing injector accelerators, namely, the current 400 MeV LINAC and the Booster, are in progress under the Proton Improvement Plan (PIP). Proton Improvement Plan-II (PIP-II) proposes to replace the existing 400 MeV LINAC by a new 800 MeV LINAC, as an injector to the Booster which will increase Booster output power by nearly a factor of two from the PIP design value by the end of its completion. In any case, the Fermilab Booster is going to play a very significant role for nearly next two decades. In this context, I have developed and investigated a new beam injection scheme called "early injection scheme" (EIS) for the Booster with the goal to significantly increase the beam intensity output from the Booster thereby increasing the beam power to the HEP experiments even before PIP-II era. The sc...

  11. Evolution of ring current formed by relativistic electron beam injection into a charge but not current neutralizing plasma

    International Nuclear Information System (INIS)

    The time evolutions of the azimuthal momentum distribution of the axisymmetrically injected electrons and the resulting ring current are self-consistently analyzed under the assumption that no return current is induced in the background plasma. It is shown that the ring current grows linearly with time for a characteristic time from the start of beam injection, and afterthere it tends to saturate at some level. The dependence of the time evolution of the ring current on the beam energy at injection and on the injection current is also obtained. (author)

  12. Sensibility Studies for the Neutral Beam Injection System in TJ-II

    International Nuclear Information System (INIS)

    The sensibility of the Neutral Beam Injection system of TJ-II to the changes of several parameters is analysed. Transmission, absorption and power loads at the intercepting structures are evaluated. The adopted values for the ion source distance, focal length and divergence are confirmed as optimal, showing a small sensitivity to changes, except for the divergence. The operational margins for beam misalignments has been found to be small but feasible, confirming also the reference directions as optimal. Finally four possible alternatives, intended to reduce the power loads at the beam entering structures, are analysed. All of them have been discarded since lead to the appearance of new risk zones, with unacceptable load levels, and reduce the transmitted power. (Author) 13 refs

  13. Laser photoionization of H0 beams for charge-changing injection

    International Nuclear Information System (INIS)

    The two-step charge-changing injection used in the Los Alamos Proton Storage Ring (PSR) requires stripping of H- to H0 by high magnetic fields and subsequent stripping of H0 to H+ by a carbon foil. The authors consider single- and multiphoton laser ionization as alternatives to using a fragile foil. The multiphoton case is of possible interest for selection of practical lasers, which tend to have increased power output at higher wavelengths. The formulas derived express the necessary laser powers for ionization of monoenergetic H0 beams; they also hold for beams of particles other than atomic hydrogen. The numerical examples given are for the 800-MeV PSR beam with momentum spread taken into account. Additionally, they discuss selective stripping as an implication of the inherent energy selectivity of the photoionization process

  14. Laser photoionization of H0 beams for charge-changing injection

    International Nuclear Information System (INIS)

    The two-step charge-changing injection used in the Los Alamos Proton Storage Ring (PSR) requires stripping of H- to H0 by high magnetic fields and subsequent stripping of H0 to H+ by a carbon foil. We consider single- and multiphoton laser ionization as alternatives to using a fragile foil. The multiphoton case is of possible interest for selection of practical lasers, which tend to have increased power output at higher wavelengths. The formulas derived express the necessary laser powers for ionization of monoenergetic H0 beams; they also hold for beams of particles other than atomic hydrogen. The numerical examples given are for the 800-MeV PSR beam with momentum spread taken into account. Additionally, we discuss selective stripping as an implication of the inherent energy selectivity of the photoionization process

  15. Numerical simulation of the processes of small-diameter high-current electron beam shaping and injection

    CERN Document Server

    Gordeev, V S; Myskov, G A

    2001-01-01

    With the aid of BEAM 25 program there was carried out the numerical simulation of the non-stationary process of shaping a small-diameter (<= 20mm) high-current hollow electron beam in a diode with magnetic insulation,as well as of the process of beam injection into the accelerating LIA track. The diode configuration for the purpose of eliminating the leakage of electron flux to the anode surface was update. Presented are the results of calculation of the injected beam characteristics (amplitude-time parameters of a current pulse, space-angle distributions of electrons etc.) depending on diode geometric parameters.

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

    Science.gov (United States)

    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.

  17. Numerical simulation of the processes of small-diameter high-current electron beam shaping and injection

    International Nuclear Information System (INIS)

    With the aid of BEAM 25 program there was carried out the numerical simulation of the non-stationary process of shaping a small-diameter (≤ 20mm) high-current hollow electron beam in a diode with magnetic insulation,as well as of the process of beam injection into the accelerating LIA track. The diode configuration for the purpose of eliminating the leakage of electron flux to the anode surface was update. Presented are the results of calculation of the injected beam characteristics (amplitude-time parameters of a current pulse, space-angle distributions of electrons etc.) depending on diode geometric parameters

  18. High-beta experiments with neutral-beam injection on PDX

    International Nuclear Information System (INIS)

    Experimental investigations of high-beta plasmas produced in PDX with near-perpendicular neutral-beam injection are reported. Systematic power scans have been performed over a wide range of toroidal fields (νsub(T)q.7 T< Bsub(T)<2.2 T) and plasma currents (200 kA< Isub(p)<500 kA). At high toroidal fields, the change in total stored energy due to beam injection increases linearly with input power and also increases with plasma current. At lower toroidal fields and low injection power levels, the stored energy also increases with power and plasma current. However, at high power and low toroidal fields, a saturation in heating is observed. This result suggests the onset of a νsub(T) limit for circular cross-section tokamaks with near-perpendicular injection. Scaling experiments indicate that this νsub(T) limit increases with rising 1/q. Values of νsub(T)approx.=3% at qsub(PSI)=1.8 have been achieved. At high values of νsub(T)q, short bursts of MHD activity are observed, synchronized with sharply increased fluxes of perpendicular charge-exchange neutrals and rapid decreases in the rate of beam-driven neutron production. When strong bursts occur, there is a significant depletion of the fast-ion population. Estimates of the fast-ion loss indicate that it could explain the observed decrease in heating, although an additional reduction in thermal-plasma confinement cannot be ruled out. Numerical studies using measured pressure profiles predict that the equilibria obtained become unstable to the ideal n=1 internal mode, at about the same value of 0 where the new fluctuations are observed. (author)

  19. Formation and sustainment of field reversed configuration (FRC) plasmas by spheromak merging and neutral beam injection

    Science.gov (United States)

    Yamada, Masaaki

    2016-03-01

    This paper briefly reviews a compact toroid reactor concept that addresses critical issues for forming, stabilizing and sustaining a field reversed configuration (FRC) with the use of plasma merging, plasma shaping, conducting shells, neutral beam injection (NBI). In this concept, an FRC plasma is generated by the merging of counter-helicity spheromaks produced by inductive discharges and sustained by the use of neutral beam injection (NBI). Plasma shaping, conducting shells, and the NBI would provide stabilization to global MHD modes. Although a specific FRC reactor design is outside the scope of the present paper, an example of a promising FRC reactor program is summarized based on the previously developed SPIRIT (Self-organized Plasmas by Induction, Reconnection and Injection Techniques) concept in order to connect this concept to the recently achieved the High Performance FRC plasmas obtained by Tri Alpha Energy [Binderbauer et al, Phys. Plasmas 22,056110, (2015)]. This paper includes a brief summary of the previous concept paper by M. Yamada et al, Plasma Fusion Res. 2, 004 (2007) and the recent experimental results from MRX.

  20. Study of the fast neutral atom beam injection on TFR tokamak

    International Nuclear Information System (INIS)

    During neutral beam injection experiments on TFR, the increase of the plasma temperature appears to be weak and is saturating at high power. This observation leads to question the classical scheme of power coupling to the thermal plasma and to check experimentally its successive steps. First of all, the neutral beam transmission and capture in the plasma, measured by calorimetric methods, are in agreement with the classical calculations. Next the confinement and thermalization of the fast ions is reviewed by means of three different measurements: charge exchange analysis of fast neutrals leaving the plasma (an auxiliary modulated neutral beam gives a spatially resolved measurement); neutron flux analysis during injection of deuterium ions into a deuterium plasma; measurement of the fast ions trapped in the toroidal magnetic field ripples. These experiments show that a non-classical mechanism transports the most energetic ions towards the plasma periphery. This phenomenon then limits the overall power that can be effectively absorbed in the plasma centre and contributes to deteriorate the energy confinement. Finally the respective role of thermal and non-thermal populations in the power balance is addressed

  1. Reconstruction of light and polarized ion beam injection system of JINR Nuclotron-nica accelerator complex

    International Nuclear Information System (INIS)

    The NICA ion collider project at JINR is under development at present. As a part of the project the Nuclotron injector upgrade has been started. The work is provided in cooperation of JINR, MEPhI and ITEP. Up to now the Nuclotron injection system consist of a number of proton and ion sources, the 650 keV pulsed preinjector and DTL linac LU-20 (Alvarez type). Such system provides injection into Nuclotron of 20 MeV proton and 5 MeV/u (Z/A >0.3) ion beams. The ion beam acceleration is realized at the 2nd harmonic of bunch travelling mode. The 650 kV high-voltage platform will be replaced by new RFQ structure. The R ampersand D of this system is discussed in the report. Results of beam dynamics simulation in RFQ and MEBT between RFQ and LU-20, electrodynamics simulation, construction of RFQ resonator, RF feeding system construction will be presented. The RF power system is assembled and tested at equivalent load and RFQ resonator manufacturing is started

  2. Beam-Based Measurement of the Waveform of the LHC Injection Kickers

    CERN Document Server

    Barnes, M J; Goddard, B; Hessler, C; Mertens, V; Uythoven, J

    2010-01-01

    Proton and ion beams are injected into LHC at 450 GeV by two kicker magnet systems, producing magnetic field pulses of up to 7.8 ms flat top duration with rise and fall times of not more than 900 ns and 3 ms, respectively. Both systems are composed of four travelling wave kicker magnets, powered by pulse forming networks. One of the stringent design requirements of these systems is a field flat top and postpulse ripple of less than ±0.5 %. A carefully matched high bandwidth system is required to obtain the required pulse response. Screen conductors are placed in the aperture of the kicker magnet to provide a path for the image current of the, high intensity, LHC beam and screen the ferrite against wake fields. However, these conductors affect the field pulse response. Recent injection tests provided the opportunity to directly measure the shape of the kick field pulse, with high accuracy, using a pilot beam. This paper details the measurements and compares the results with predictions and laboratory measurem...

  3. ? modification by means of counter-neutral beam injection in a low-? plasma

    Science.gov (United States)

    Kim, J.; Burrell, K. H.; Groebner, R. J.; Hinton, F. L.; Sager, G. T.; Staebler, G. M.; Stambaugh, R. D.

    1996-08-01

    The idea of controlling the radial electric field 0741-3335/38/8/059/img3 by means of a radial current resulting from ion orbit loss caused by counter neutral beam injection has been theoretically and experimentally investigated. A large fraction (0741-3335/38/8/059/img4%) of the 75 keV deuterium ions counter-injected into a low-0741-3335/38/8/059/img5 plasma (0741-3335/38/8/059/img6 MA) suffers prompt orbit loss, which forces an inward ion current to maintain charge neutrality. Monte Carlo guiding-centre orbit calculations predict a radial current of 80 A at the last closed flux surface. In these discharges, 0741-3335/38/8/059/img7 is negative everywhere, owing to the counter-going toroidal rotation, and exhibits a double-bump shape, in contrast to the usual positive parabolic shape for the co-injection case. The measured carbon impurity ion toroidal rotation profile shows a pedestal over the outer region where fast ions are lost, possibly due to the effect of 0741-3335/38/8/059/img8 torque. The momentum diffusion process tends to slow down and to spatially spread the 0741-3335/38/8/059/img8 torque effect. The L - H transition did not occur more quickly in these discharges than in similar co-injected discharges.

  4. Internal Transport Barrier in Edge Plasma of Small Size Divertor Tokamak Using Neutral Beam Injection

    Science.gov (United States)

    Bekheit, A. H.

    2013-08-01

    We model the internal transport barrier "ITB" in edge plasma of small size divertor tokamak with B2SOLPS0.5.2D fluid transport code. The simulation results demonstrated the following: (1) we control the internal transport barrier by altering the edge particle transport through changes the edge toroidal rotation which agree with the result of Burrell et al. (Edge Pedestal control in quiescent H-mode discharges in DIII-D using co-plus counter-neutral beam injection, Nucl Fusion, 49, 085024 (9pp) in 2009). (2) The radial electric field has neoclassical nature near separatrix with discharge by co-injection NBI. (3) The toroidal plasma viscosity has strong influence on the toroidal velocity.

  5. Prompt Loss of Energetic Ions during Early Neutral Beam Injection in the National Spherical Torus Experiment

    International Nuclear Information System (INIS)

    Early neutral-beam injection is used in the National Spherical Torus Experiment (NSTX) to heat the electrons and slow current penetration which keeps q(0) elevated to avoid deleterious MHD activity and at the same time reduces Ohmic flux consumption, all of which aids long-pulse operation. However, the low plasma current (Ip ∼ 0.5 MA) and electron density (ne ∼ 1 x 1013 cm-3) attending early injection lead to elevated orbit and shine through losses. The inherent orbit losses are aggravated by large excursions in the outer gap width during current ramp-up. An investigation of this behavior using various energetic particle diagnostics on NSTX and TRANSP code analysis is presented

  6. Programmable extraction of different energy proton beam to an experimental facility in the process of injection into the IHEP synchrotron

    International Nuclear Information System (INIS)

    The programmable different energy proton beam extraction to an experimental facility of the IHEP under injection to the IHEP proton synchrotron is realized in the following way; after inquiry from the IHEP EF transfer to a lower extraction energy and beam extraction to EF are performed. 1 ref.; 1 fig

  7. Solid state generator for powerful radio frequency ion sources in neutral beam injection systems

    International Nuclear Information System (INIS)

    Radio frequency ion sources used in neutral beam injection systems (NBI) of fusion machines are currently supplied by self-excited RF generators. These generators have both a low power efficiency and a limited frequency stability, therefore transistorized amplifiers are being considered for the power supply of the next generation of RF sources. A 75 kW generator, originally designed for broadcasting, has been tested with a negative ion source. High operational reliability and a very good matching to the plasma load has been demonstrated. These results make this generator type a very promising candidate for future NBI systems

  8. Solid state generator for powerful radio frequency ion sources in neutral beam injection systems

    Energy Technology Data Exchange (ETDEWEB)

    Kraus, W.; Fantz, U.; Heinemann, B.; Franzen, P.

    2015-02-15

    Radio frequency ion sources used in neutral beam injection systems (NBI) of fusion machines are currently supplied by self-excited RF generators. These generators have both a low power efficiency and a limited frequency stability, therefore transistorized amplifiers are being considered for the power supply of the next generation of RF sources. A 75 kW generator, originally designed for broadcasting, has been tested with a negative ion source. High operational reliability and a very good matching to the plasma load has been demonstrated. These results make this generator type a very promising candidate for future NBI systems.

  9. Field reversed configuration confinement enhancement through edge biasing and neutral beam injection.

    Science.gov (United States)

    Tuszewski, M; Smirnov, A; Thompson, M C; Korepanov, S; Akhmetov, T; Ivanov, A; Voskoboynikov, R; Schmitz, L; Barnes, D; Binderbauer, M W; Brown, R; Bui, D Q; Clary, R; Conroy, K D; Deng, B H; Dettrick, S A; Douglass, J D; Garate, E; Glass, F J; Gota, H; Guo, H Y; Gupta, D; Gupta, S; Kinley, J S; Knapp, K; Longman, A; Hollins, M; Li, X L; Luo, Y; Mendoza, R; Mok, Y; Necas, A; Primavera, S; Ruskov, E; Schroeder, J H; Sevier, L; Sibley, A; Song, Y; Sun, X; Trask, E; Van Drie, A D; Walters, J K; Wyman, M D

    2012-06-22

    Field reversed configurations (FRCs) with high confinement are obtained in the C-2 device by combining plasma gun edge biasing and neutral beam injection. The plasma gun creates an inward radial electric field that counters the usual FRC spin-up. The n = 2 rotational instability is stabilized without applying quadrupole magnetic fields. The FRCs are nearly axisymmetric, which enables fast ion confinement. The plasma gun also produces E × B shear in the FRC edge layer, which may explain the observed improved particle transport. The FRC confinement times are improved by factors 2 to 4, and the plasma lifetimes are extended from 1 to up to 4 ms. PMID:23004613

  10. High frequency cascaded resonant transformer rectifier power supply for neutral beam injection

    International Nuclear Information System (INIS)

    Neutral beam injection for fusion requires DC megavolt power sources at several amperes. The conventional methods of using series or shunt fed multipliers cannot provide the current while the 60 Hz coupled transformer method is difficult to modularize because of size and stores excessive amounts of energy. A technique which borrows from several technologies has been investigated and shows promise for a satisfactory solution. This technique uses resonant multistage high frequency (100 kHz) series coupled ferrite transformer with rectifiers to produce megavolts at several amperes of current. Modularity, high efficiency and low energy storage are desirable features of this power source

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

    Science.gov (United States)

    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.

  12. Calorimeter design-aspects for neutral beam injection on W7-X

    Energy Technology Data Exchange (ETDEWEB)

    Holtum, D., E-mail: holtum@ipp.mpg.de [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Postfach 1533, D-85740 Garching (Germany); Froeschle, M.; Heinemann, B. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Postfach 1533, D-85740 Garching (Germany); Liebe, T. [Fa. Xenos GmbH, Jugendstr. 2, D-81667 Muenchen (Germany); Nocentini, R.; Riedl, R.; Rong, P. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Postfach 1533, D-85740 Garching (Germany); Schubert, W. [Fa. Xenos GmbH, Jugendstr. 2, D-81667 Muenchen (Germany); Staebler, A. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Postfach 1533, D-85740 Garching (Germany)

    2011-10-15

    Neutral Beam Injection (NBI) is one of the heating systems for Wendelstein 7-X (W7-X). The beam power of the NBI is measured calorimetrically. Using the knowledge gained from ASDEX-Upgrade operation, the complete calorimeter was re-designed. The design-aspects and the necessary improvements for operation on W7-X are described in this paper. The main aspects improved concern: (i) the adapted slope of the winding drum at the lift, (ii) the adjustable acceleration/deceleration ramp and integrated position sensors, (iii) the improvements of panels in the body, (iv) the accessibility for mounting panels, (v) the water-distribution, and (vi) the centering of the body on the support to fix and reproduce the measuring position. The manufacturing is in progress, installation will start in 2011 and the commissioning is scheduled for the end of 2014.

  13. Calorimeter design-aspects for neutral beam injection on W7-X

    International Nuclear Information System (INIS)

    Neutral Beam Injection (NBI) is one of the heating systems for Wendelstein 7-X (W7-X). The beam power of the NBI is measured calorimetrically. Using the knowledge gained from ASDEX-Upgrade operation, the complete calorimeter was re-designed. The design-aspects and the necessary improvements for operation on W7-X are described in this paper. The main aspects improved concern: (i) the adapted slope of the winding drum at the lift, (ii) the adjustable acceleration/deceleration ramp and integrated position sensors, (iii) the improvements of panels in the body, (iv) the accessibility for mounting panels, (v) the water-distribution, and (vi) the centering of the body on the support to fix and reproduce the measuring position. The manufacturing is in progress, installation will start in 2011 and the commissioning is scheduled for the end of 2014.

  14. Time- and spatial-behaviours of metal impurity during neutral-beam injection on the JFT-2 tokamak

    International Nuclear Information System (INIS)

    The detailed time- and spatial-behaviours of emissions from iron impurities with the different ionic charge were obtained in the JFT-2 deutrium discharges with co- or counter-injections. In co-injection, the iron impurity is driven out from the central region of the plasma, and in counter-injection, they appear to accumulate and the plasma is not disrupted. These enhanced diffusion of the iron impurity can well be explained by the neutral-beam induced effect (direct beam-impurity interaction and toroidal rotation of the plasma), predicted by the neoclassical theory. (author)

  15. Hydrogen cluster-like behaviour during supersonic molecular beam injection on the HL-1M tokamak

    International Nuclear Information System (INIS)

    Pulsed supersonic molecular beam injection (SMBI) has been developed successfully and used in the HL-1M tokamak. It is an attempt to enhance the penetration depth and fuelling efficiency. With a penetration depth of hydrogen particles beyond 8 cm, the rising rate of electron density, dn-bare/dt, was up to 7.6x1020m-3·s-1 without disruption, and reached the highest plasma density n-bare=8.2x1019m-3 on HL-1M. With SMBI the plasma energy confinement time, τE, measured by diamagnetism is 10-30 % longer than that with gas puffing when other discharge conditions are kept the same. The fuelling method of SMBI has recently been improved to make a survey of the cluster effects within the beam. A series of new phenomena show the interaction of the beam (including clusters) with the toroidal plasma. Hydrogen clusters may be produced in the beam according to the Hagena empirical scaling law of clustering onset, Γ*=(kd0.85P0)/T02.29). If Γ*>100, clusters will form. In the present experiment Γ* is about 127. (author)

  16. Peculiarities of heat transfer in the experiments of beam injection heating of a plasma at the GOL-3 device

    International Nuclear Information System (INIS)

    The dynamics is discussed of the heat redistribution in plasma, heated by microsecond relativistic electron beam in the GOL-3 facility. The electron temperature dependence on time and distance up to beam injection point are compared with heat transfer calculations. At the stage of plasma cooling the time dependence of the plasma temperature is well described by the classical electron heat conduction on the facility buttends. At the same time the dynamics of the observed electron temperature increase and its distribution in the facility length during beam injection time can not be explained by the classical electron heat conduction. 15 refs.; 9 figs

  17. Impurity Dynamics under Neutral Beam Injection at TJ-II (simulation)

    International Nuclear Information System (INIS)

    In this study the simulations of plasma transport under NBI for TJ-II, previously performed, are extended. Since than a considerable number of important modifications have been introduced in the model: change of magnetic configuration, use of experimental initial profiles, expansion of the Data base from NBI calculations and, mainly, a detailed handling of impurities with inclusion of sputtering effects. Moreover there is now a particular emphasis on the analysis of the conditions for discharge collapse and on the possible effects of single beam injection. This analysis of impurity behaviour with sputtering shows that in the expected usual cases there is no radioactive collapse and that if the recycling coefficients remain lower the unity it is always possible to find a strategy for external gas puffing leading to a stationary state, with densities below the limit and efficient NBI absorption (>50%). The radioactive collapse can appear either at high densities (central value higher than 1.4x10''20 m''3), excessive influx of impurities (i. e. with sputtering rates higher than twice the expected values) o for insufficient injected beam power (less than 45 kW). The present study analyses only the 1004464 configuration of TJ-II, but future works will start a systematic scan of configuration using this same model. (Author) 12 Refs

  18. Wakefield-Induced Ionization injection in beam-driven plasma accelerators

    CERN Document Server

    de la Ossa, A Martinez; Streeter, M J V; Osterhoff, J

    2015-01-01

    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. The electron-beam drivers must feature high-peak currents ($I_b^0\\gtrsim 8.5~\\mathrm{kA}$) 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 ($k_p\\sigma_z \\sim k_p\\epsilon_n \\sim 0.1$). In additi...

  19. SPS Injection and Beam Quality for LHC Heavy Ions With 150 ns Kicker Rise Time

    CERN Document Server

    Goddard, Brennan; Ducimetière, Laurent; Kotzian, Gerd; Uythoven, Jan; Velotti, Francesco

    2016-01-01

    As part of the LHC Injectors Upgrade project for LHC heavy ions, the SPS injection kicker system rise time needs reduction below its present 225 ns. One technically challenging option under consideration is the addition of fast Pulse Forming Lines in parallel to the existing Pulse Forming Networks for the 12 kicker magnets MKP-S, targeting a system field rise time of 100 ns. An alternative option is to optimise the system to approach the existing individual magnet field rise time (2-98%) of 150 ns. This would still significantly increase the number of colliding bunches in LHC while minimising the cost and effort of the system upgrade. The observed characteristics of the present system are described, compared to the expected system rise time, together with results of simulations and measurements with 175 and 150 ns injection batch spacing. The expected beam quality at injection into LHC is quantified, with the emittance growth and simulated tail population taking into account expected jitter and synchronisatio...

  20. Generation of Low Absolute Energy Spread Electron Beams in Laser Wakefield Acceleration Using Tightly Focused Laser through Near-Ionization-Threshold Injection

    CERN Document Server

    Li, F; Wan, Y; Wu, Y P; Hua, J F; Pai, C H; Lu, W; Mori, W B; Joshi, C

    2015-01-01

    An enhanced ionization injection scheme using a tightly focused laser pulse with intensity near the ionization potential to trigger the injection process in a mismatched pre-plasma channel has been proposed and examined via multi-dimensional particle-in-cell simulations. The core idea of the proposed scheme is to lower the energy spread of trapped beams by shortening the injection distance. We have established theory to precisely predict the injection distance, as well as the ionization degree of injection atoms/ions, electron yield and ionized charge. We have found relation between injection distance and laser and plasma parameters, giving a strategy to control injection distance hence optimizing beam's energy spread. In the presented simulation example, we have investigated the whole injection and acceleration in detail and found some unique features of the injection scheme, like multi-bunch injection, unique longitudinal phase-space distribution, etc. Ultimate electron beam has a relative energy spread (rm...

  1. Ion cyclotron instabilities driven by the nearly perpendicular neutral beam injection in the Wendelstein VII-A stellarator

    International Nuclear Information System (INIS)

    The problem of ion cyclotron instabilities driven by the high power neutral beam injection is investigated for the conditions of the W VII-A stellarator by means of linear stability analysis. On the basis of only collisional (classical) slowing down, beam ion distribution functions are calculated by means of Monte Carlo simulation. In this report, various cases are considered: Transient beam ion distributions (i) immediately after switch on the neutral beam injection and (ii) after half of an average slowing down time; stationary beam ion distributions (iii) for confinement properties strongly improved by radial electric fields, transport and fast orbit losses are neglected for these situations, and (iv) for worse confinement properties for which the average beam ion confinement time is of the order of the average slowing down time. Furthermore, the distribution functions of the ions originating from the neutral beam injection are estimated for the early phase of the discharges with low temperatures and for the later phase with maximum ion temperatures. (orig.)

  2. Self-Injection and Acceleration of Monoenergetic Electron Beams from Laser Wakefield Accelerators in a Highly Relativistic Regime

    International Nuclear Information System (INIS)

    Self-injection and acceleration of monoenergetic electron beams from laser wakefield accelerators are first investigated in the highly relativistic regime, using 100 TW class, 27fs laser pulses. Quasi-monoenergetic multi-bunched beams with energies as high as multi-hundred MeV are observed with simultaneous measurements of side-scattering emissions that indicate the formation of self-channelling and self-injection of electrons into a plasma wake, referred to as a 'bubble'. The three-dimensional particle-in-cell simulations confirmed multiple self-injection of electron bunches into the bubble and their beam acceleration with gradient of 1.5GeV/cm. (physics of gases, plasmas, and electric discharges)

  3. Self-Injection and Acceleration of Monoenergetic Electron Beams from Laser Wakefield Accelerators in a Highly Relativistic Regime

    Institute of Scientific and Technical Information of China (English)

    H. Yoshitama; WEN Xian-Lun; WEN Tian-Shu; WU Yu-Chi; ZHANG Bao-San; ZHU Qi-Hua; HUANG Xiao-Jun; AN Wei-Min; HUNG Wen-Hui; TANG Chuan-Xiang; LIN Yu-Zheng; T. Kameshima; WANG Xiao-Dong; CHEN Li-Ming; H. Kotaki; M. Kando; K. Nakajima; GU Yu-Qiu; GUO Yi; JIAO Chun-Ye; LIU Hong-Jie; PENG Han-Sheng; TANG Chuan-Ming; WANG Xiao-Dong

    2008-01-01

    @@ Self-injection and acceleration of monoenergetic electron beams from laser wakefield accelerators are first in-vestigated in the highly relativistic regime, using 100 TW class, 27 fs laser pulses. Quasi-monoenergetic multi-bunched beams with energies as high as multi-hundredMeV are observed with simultaneous measurements of side-scattering emissions that indicate the formation of self-channelling and self-injection of electrons into a plasma wake, referred to as a 'bubble'. The three-dimensional particle-in-cell simulations confirmed multiple self-injection of electron bunches into the bubble and their beam acceleration with gradient of 1.5 GeV/cm.

  4. Modeling and control of plasma rotation for NSTX using neoclassical toroidal viscosity and neutral beam injection

    Energy Technology Data Exchange (ETDEWEB)

    Goumiri, I. R. [Princeton Univ., NJ (United States). Mechanical and Aerospace Dept.; Rowley, C. W. [Princeton Univ., NJ (United States). Mechanical and Aerospace Dept.; Sabbagh, S. A. [Columbia Univ., New York, NY (United States). Dept. of Applied Physics and Applied Mathematics; Gates, D. A. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Gerhardt, S. P. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Boyer, M. D. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Andre, R. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Kolemen, E. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Taira, K. [Florida State Univ, Dept Mech Engn, Tallahassee, FL USA.

    2016-02-19

    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.

  5. Modeling and control of plasma rotation for NSTX using neoclassical toroidal viscosity and neutral beam injection

    Science.gov (United States)

    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.

  6. An IGBT Driven Slotted Beam Pipe Kicker for SPEAR III Injection

    International Nuclear Information System (INIS)

    The SPEAR III injection kicker system is composed of three kicker magnets, K1, K2, and K3. These magnets, along with the power modulators to drive them constitute an injection system which will be used to deflect an incoming electron beam with an energy of 3.3 GeV by an angle of 2.5 mrad for K1 and K3, and 1 mrad for K2. The pulse shape of the magnetic field in the three magnets must be matched in order to preserve a closed orbit. The pulse duration is required to be less than 780 ns, with rise and fall times of less than 375 ns, and a pulse repetition frequency of 10 Hz. The aperture of all three magnets is 60 x 34 mm in an 8 inch vacuum vessel. The magnetic length is 1.2 m for K1 and K3, and 0.6 m for K2 [1]. The magnet design employs a slotted beam pipe which is shorted at one end. A solid state IGBT based, induction type of modulator drives the magnets. Modulators for K1 and K3 consist of eight 4.5 kV, 600 A IGBTs, and eight Finemet magnet cores with four 22.5 Ohm output cables to drive 2381 A into the magnets. The modulator for K2 uses four IGBTs and cores, and 8 output cables to produce a 2619 A pulse. Cables of length greater than one half the pulse width must be used in order to avoid reflections from the shorted magnet. The design charge voltage for the modulators is 20 kV for K1 and K3. This paper describes the magnet and modulator design, as and presents test data from a prototype system

  7. Explanation of Turbulent Suppression of Electron Heat Transfer in GOL-3 Facility at the Stage of Relativistic Electron Beam Injection

    International Nuclear Information System (INIS)

    The effect of the electron heat transfer suppression during the stage of relativistic electron beam injection into a plasma was discovered experimentally more than a decade ago. It is now widely adopted that the suppression is a side sequel of Langmuir turbulence excited by the beam, however neither quantitative theory nor even rough estimates of the phenomena were available so far. We argue that the coefficient of turbulent thermal conductivity can be evaluated from a robust judgement based on the energy balance consideration

  8. Excitation of HF and ULF-VLF waves during charged particle beams injection in active space experiment

    Czech Academy of Sciences Publication Activity Database

    Baranets, N. V.; Sobolev, Y. P.; Ruzhin, Yu. Ya.; Rothkaehl, H.; Erokhin, N. S.; Afonin, V. V.; Vojta, Jaroslav; Šmilauer, Jan

    2009-01-01

    Roč. 8, - (2009), s. 251-256. ISSN 1883-9630. [International Congress on Plasma Physics 2008/14st./. Fukuoka, 08.09.2008-12.09.2008] Institutional research plan: CEZ:AV0Z30420517 Keywords : beam-into-beam injection * waves excitation * dipole antenna Subject RIV: BL - Plasma and Gas Discharge Physics http://www.jspf.or.jp/JPFRS/PDF/Vol8/jpfrs2009_08-0251.pdf

  9. Monte Carlo simulations of neutral beam injection into the TJ-II helical-axis stellarator

    International Nuclear Information System (INIS)

    The neutral beam injection (NBI) efficiency for the TJ-II helical-axis stellarator was studied by Monte Carlo simulations for the case of tangential injection. For benchmark purposes, two different NBI codes are applied which take into account the peculiar geometries of the NBI, vacuum vessel, and helical-indented magnetic surfaces in TJ-II. The results obtained for various plasma parameters are discussed, emphasis being placed on comparing the co- and counter-heating efficiencies and considering loss mechanisms. The results from the two codes are in good agreement if differences in the magnetic field configurations used are borne in mind. The Monte Carlo code, which treats the guiding center part in magnetic coordinates, was used to investigate the influence of an assumed radial electric field on the heating efficiency. An interesting type of resonance which enhances fast orbit losses has been found for ωpol/ωtor ∼ 2 (with ωpol and ωtor being the poloidal and toroidal frequencies of the fast ions, respectively). This critical ratio can be reached during slowing-down owing to the vector E x vector B-drift. (orig.)

  10. Low energy spread electron beams from ionization injection in a weakly relativistic laser wakefield accelerator

    International Nuclear Information System (INIS)

    We show via two-dimensional particle-in-cell simulations that low energy spread, relativistic electron beams (>120 MeV, <15%) can be produced in the weakly non-linear regime of a plasma wakefield, driven by a moderate power laser pulse (initial a0 < 1). Higher ionization states of a high-Z trace species, mixed in a background H plasma, provide the source of injected electrons. Injection occurs even though the laser intensity is initially well below the trapping threshold, as it is found that the laser pulse evolves until it fulfils the trapping requirements through self-compression. By careful control of intensity and density, the amount of evolution and hence of trapping can be controlled. Acceleration is terminated by depletion due to the extended evolution time, leading to narrow energy spread features even for long interaction lengths. Particle tracking shows that electrons ‘born’ at the periphery of the laser pulse are more likely to follow smoother trajectories inside the wakefield and subsequently to be trapped and accelerated. (paper)

  11. Comparisons between tokamak fueling of gas puffing and supersonic molecular beam injection in 2D simulations

    International Nuclear Information System (INIS)

    Plasma fueling with high efficiency and deep injection is very important to enable fusion power performance requirements. It is a powerful and efficient way to study neutral transport dynamics and find methods of improving the fueling performance by doing large scale simulations. Two basic fueling methods, gas puffing (GP) and supersonic molecular beam injection (SMBI), are simulated and compared in realistic divertor geometry of the HL-2A tokamak with a newly developed module, named trans-neut, within the framework of BOUT++ boundary plasma turbulence code [Z. H. Wang et al., Nucl. Fusion 54, 043019 (2014)]. The physical model includes plasma density, heat and momentum transport equations along with neutral density, and momentum transport equations. Transport dynamics and profile evolutions of both plasma and neutrals are simulated and compared between GP and SMBI in both poloidal and radial directions, which are quite different from one and the other. It finds that the neutrals can penetrate about four centimeters inside the last closed (magnetic) flux surface during SMBI, while they are all deposited outside of the LCF during GP. It is the radial convection and larger inflowing flux which lead to the deeper penetration depth of SMBI and higher fueling efficiency compared to GP

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

    Science.gov (United States)

    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.

  13. Experiments of synchrotron injection using the direct fast chopped H- beam extracted from surface-plasma-type negative hydrogen ion source

    International Nuclear Information System (INIS)

    An experiment of synchrotron injection using the direct fast chopped H- beam extracted from a surface-plasma-type H- ion source has been successfully achieved. The injection phase of the fast chopped beam from linac into the booster synchrotron is adjustable against the center of rf bucket by using this beam. It was obtained that the longitudinal emittance was controlled at the extraction of the booster synchrotron, and that the beam loss during the injection into main ring of the KEK-PS was reduced by this fast chopped beam. (author)

  14. Feasibility Study of the PS Injection for 2 GeV LIU Beams with an Upgraded KFA-45 Injection Kicker System Operating in Short Circuit Mode

    CERN Document Server

    Kramer, Thomas; Borburgh, Jan; Ducimetière, Laurent; Feliciano, Luis; Ferrero Colomo, Alvaro; Goddard, Brennan; Sermeus, Luc

    2016-01-01

    Under the scope of the LIU project the CERN PS Booster to PS beam transfer will be modified to match the requirements for the future 2 GeV beams. This paper describes the evaluation of the proposed upgrade of the PS injection kicker. Different schemes of an injection for LIU beams into the PS have been outlined in the past already under the aspect of individual transfer kicker rise and fall time performances. Homogeneous rise and fall time requirements in the whole PSB to PS transfer chain have been established which allowed to consider an upgrade option of the present injection kicker system operated in short circuit mode. The challenging pulse quality constraints require an improvement of the flat top and post pulse ripples. Both operation modes, terminated and short circuit mode are analysed and analogue circuit simulations for the present and upgraded system are outlined. Recent measurements on the installed kickers are presented and analysed together with the simulation data. First measurements verifying...

  15. ACTIVE LONGITUDINAL PAINTING FOR THE H-CHARGE EXCHANGE INJECTION OF THE LINAC4 BEAM INTO THE PS BOOSTER

    CERN Document Server

    CARLI, C; CERN. Geneva. AB Department

    2008-01-01

    Linac4 will provide 160 MeV H- to the PS Booster synchrotron. The H-beam will be injected by charge exchange injection allowing injecting several times into the same volumes of phase space. Thus, a large number of turns can be injected with high efficiencies and â€ワpainting” in order to shape the initial particle distribution for optimum performance becomes possible. In particular, a chopper makes longitudinal painting possible in addition to painting in transverse phase spaces. The slow synchrotron motion in the PS Booster implies an active longitudinal painting scheme, where the Linac4 output energy is modulated. Several active longitudinal painting schemes are presented. One scheme, based on a triangular Linac energy modulation, is proposed for the PS Booster H- injection with Linac4.

  16. Evolution of High Intensity Beams in the CERN PS Booster after H⁻ Injection and Phase Space Painting

    CERN Document Server

    Cieslak-Kowalska, Magdalena; Benedetto, Elena; Bracco, Chiara

    2016-01-01

    With the LHC Injector Upgrade (LIU) project, the injection energy of PS Booster (PSB) ' first circular accelerator in the LHC injector chain ' will be raised from 50 MeV to 160 MeV and the present multiturn injection will be upgraded to H⁻ injection with transverse and longitudinal painting. In the scope of this project, it is planned to double the beam intensities, profiting from the fact that the βγ2 factor will be two times larger (0.35 at 50 MeV and 0.71 at 160 MeV), so the resulting tune spread driven by a direct space charge should remain similar. This paper describes the feasibility to double the intensity of high intensity and large emittance beams, looking into the evolution under space charge and taking into account losses constrains in the ring and in the extraction lines.

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

    CERN Document Server

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

    2016-01-01

    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 $2.4\\rm \\mu m$ and $0.8\\rm \\mu m$ for wakefield excitation and for triggering electron injection via field ionization, respectively. A laser pulse at $2.4\\rm \\mu m$ wavelength enables one to drive an intense acceleration structure with 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 full three dimensional particle-in-cell simulations show that electron beams at the GeV energy level with both low energy spreads (around one percent) and high charges (several tens of picocoulomb) can be obtained by this scheme with laser parameters achievable in the near future.

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

    Science.gov (United States)

    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.

  19. Effect of supersonic molecular-beam injection on edge fluctuation and particle transport in Heliotron J

    Energy Technology Data Exchange (ETDEWEB)

    Zang, L., E-mail: l-zang@center.iae.kyoto-u.ac.jp; Kasajima, K.; Hashimoto, K.; Kenmochi, N. [Graduate School of Energy Science, Kyoto University, Uji 611-0011 (Japan); Ohshima, S.; Mizuuchi, T.; Yamamoto, S.; Sha, M.; Nagasaki, K.; Kado, S.; Okada, H.; Minami, T.; Kobayashi, S.; Shi, N.; Konoshima, S.; Nakamura, Y.; Sano, F. [Institute of Advanced Energy, Kyoto University, Gokasho, Uji 611-0011 (Japan); Nishino, N. [Graduate School of Engineering, Hiroshima University, Higashihiroshima 739-8527 (Japan); Takeuchi, M. [Naka Fusion Institute, Japan Atomic Energy Agency, Naka 311-0193 (Japan); Mukai, K. [National Institute for Fusion Science, Toki 509-5292 (Japan); and others

    2014-04-15

    Edge fluctuation in a supersonic molecular-beam injection (SMBI) fueled plasma has been measured using an electrostatic probe array. After SMBI, the plasma stored energy (W{sub p}) temporarily decreased then started to increase. The local plasma fluctuation and fluctuation induced particle transport before and after SMBI have been analyzed. In a short duration (∼4 ms) just after SMBI, the density fluctuation of broad-band low frequency increased, and the probability density function (PDF) changed from a nearly Gaussian to a positively skewed non-Gaussian one. This suggests that intermittent structures were produced due to SMBI. Also the fluctuation induced particle transport was greatly enhanced during this short duration. About 4 ms after SMBI, the low frequency broad-band density fluctuation decreased, and the PDF returned to a nearly Gaussian shape. Also the fluctuation induced particle transport was reduced. Compared with conventional gas puff, W{sub p} degradation window is very short due to the short injection period of SMBI. After this short degradation window, fluctuation induced particle transport was reduced and W{sub p} started the climbing phase. Therefore, the short period of the influence to the edge fluctuation might be an advantage of this novel fueling technique. On the other hand, although their roles are not identified at present, coherent MHD modes are also suppressed as well by the application of SMBI. These MHD modes are thought to be de-exited due to a sudden change of the edge density and/or excitation conditions.

  20. Ion beam injected point defects in crystalline silicon: Migration, interaction, and trapping phenomena

    International Nuclear Information System (INIS)

    The recent work on the room temperature migration and trapping phenomena of ion beam generated point defects in crystalline Si is reviewed. It is shown that a small fraction (∼10-6) of the defects generated at the surface by a shallow implant is injected into the bulk. These defects undergo a long range trap-limited diffusion and interact with both impurities, dopants and preexisting defects along their path. In particular, these interactions result in dopant deactivation and/or partial annihilation of pre-existing vacancy-type defect markers. It is found that in highly pure, epitaxial Si layers, these effects extend to several microns from the surface, demonstrating a long range migration of point defects at room temperature. By a detailed analysis of the experimental evidences the authors have identified the Si self-interstitials as the major responsible for the observed phenomena. This allowed them to give a lower limit of 6 x 10-11 cm2/s for the room temperature diffusion coefficient of the Si self-interstitials. Room temperature trap-limited migration of vacancies is also detected as a broadening in the divacancy profile of as implanted samples. In this case the room temperature diffusion coefficient of vacancies has been found to be ≥3 x 10-12 cm2/s. These data are presented and their implications discussed

  1. Fishbone activity in experimental advanced superconducting tokamak neutral beam injection plasma

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Liqing; Zhang, Jizong; Chen, Kaiyun, E-mail: Kychen@ipp.cas.cn, E-mail: lqhu@ipp.cas.cn; Hu, Liqun, E-mail: Kychen@ipp.cas.cn, E-mail: lqhu@ipp.cas.cn; Li, Erzhong; Lin, Shiyao; Shi, Tonghui; Duan, Yanmin [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Zhu, Yubao [Department of Physics and Astronomy, University of California, Irvine, California 92697-4575 (United States)

    2015-12-15

    Repetitive fishbones near the trapped ion procession frequency were observed for the first time in the neutral beam injection high confinement plasmas in Experimental Advanced Superconducting Tokamak (EAST) tokamak, and diagnosed using a solid-state neutral particle analyzer based on a compact silicon photodiode together with an upgraded high spatial-temporal-resolution multi-arrays soft X-ray (SX) system. This 1/1 typical internal kink mode propagates in the ion-diamagnetism direction with a rotation speed faster than the bulk plasma in the plasma frame. From the SX measurements, this mode frequency is typical of chirping down and the energetic particle effect related to the twisting mode structure. This ion fishbone was found able to trigger a multiple core sawtooth crashes with edge-2/1 sideband modes, as well as to lead to a transition from fishbone to long lived saturated kink mode to fishbone. Furthermore, using SX tomography, a correlation between mode amplitude and mode frequency was found. Finally, a phenomenological prey–predator model was found to reproduce the fishbone nonlinear process well.

  2. ProVac3D and application to the neutral beam injection system of ITER

    International Nuclear Information System (INIS)

    We have developed ProVac3D (3D density Profiles in Vacuum systems), a Monte Carlo simulation code, to calculate gas dynamics and the density profiles in a complex vacuum system characterized by distributed gas sources and pumps. The Neutral Beam Injection System of ITER is a good example of such a system, for which Forschungszentrum Karlsruhe is responsible to design the state-of-the-art cryogenic pump. By using ProVac3D, we can intensively study volumes of interest inside NBI and get the information about the pumping speed in order to provide the required density profile along the beamline. The advantage of ProVac3D is that it is flexible with modular structures and very fast to achieve precise statistics by large simulation numbers even with a current desktop computer. To extend ProVac3D beyond the free molecular regime, the collision of the probe molecule with the gas background has been included. We are going to present some preliminary results as well.

  3. Influence of Off-axis Neutral Beam Injection on Resistive Wall Mode Stability

    International Nuclear Information System (INIS)

    Full text: The stabilization of the resistive wall mode (RWM) is an essential issue for future magnetic fusion reactors (e.g., ITER) aiming at long-duration steady discharges over the no-wall beta limit. The RWM has been extensively investigated during recent years, both theoretically and experimentally. However, so far the physical mechanism of the passive control of the RWM has not been investigated fully, particularly the mechanism for the interaction between the RWM and energetic particles (EPs). Recent experiments in DIII-D indicate that the increase of the off-axis neutral beam injection (NBI) power can lead to the enhancement of RWM stability, which is opposite to expectation from consideration of the trapped particles fraction reduced by off-axis NBI. In this work, we apply our previous theory model to investigate the deposition effect of trapped EPs from off-axis NBI on the RWM instability. The results show that the spatial deposition effect of trapped EPs indeed significantly affects the RWM stability, and, compared with the on-axis case, off-axis deposition of EPs can contribute more stabilization to the RWM. (author)

  4. Characteristics of the SF6/H2 laser initiated by an axially injected electron-beam

    International Nuclear Information System (INIS)

    The experimental and analytical studies on the characteristics of SF6/H2 laser were performed. The experimental apparatus consisted of a low-impedance Marx generator, an electric field emission diode, a laser tube, and an axial field coil. The electron beam of 320 KeV and 2.5 kA was injected into SF6/H2 gas. A simulation model to derive laser parameters is the rate equation model which includes ignition reaction, excitation reaction and relaxation reaction. The laser energy, the wave form of laser pulses, photon production rate and the number of produced molecules of HF were derived from the model. The maximum laser power was 450 mJ with the FWHM of 160 ns, when the gas mixing ratio of SF6/H2 was 11 to 1 and the gas pressure was 120 Torr. The optimum length of a laser tube was about 500 mm. The generation efficiency of laser was 4.9 percent. The values of laser parameters obtained from the simulation were 2.0 x 10-3 of the F atom dissociation of SF6 and 15.7 eV/F of the production energy of one F atom. (Kato, T.)

  5. Fishbone activity in experimental advanced superconducting tokamak neutral beam injection plasma

    International Nuclear Information System (INIS)

    Repetitive fishbones near the trapped ion procession frequency were observed for the first time in the neutral beam injection high confinement plasmas in Experimental Advanced Superconducting Tokamak (EAST) tokamak, and diagnosed using a solid-state neutral particle analyzer based on a compact silicon photodiode together with an upgraded high spatial-temporal-resolution multi-arrays soft X-ray (SX) system. This 1/1 typical internal kink mode propagates in the ion-diamagnetism direction with a rotation speed faster than the bulk plasma in the plasma frame. From the SX measurements, this mode frequency is typical of chirping down and the energetic particle effect related to the twisting mode structure. This ion fishbone was found able to trigger a multiple core sawtooth crashes with edge-2/1 sideband modes, as well as to lead to a transition from fishbone to long lived saturated kink mode to fishbone. Furthermore, using SX tomography, a correlation between mode amplitude and mode frequency was found. Finally, a phenomenological prey–predator model was found to reproduce the fishbone nonlinear process well

  6. Enhancements of Machine Reliability and Beam Quality in SPring-8 Linac for Top-Up Injection into Two Storage Rings

    CERN Document Server

    Hanaki, Hirofumi; Dewa, Hideki; Kobayashi, Toshiaki; Mizuno, Akihiko; Suzuki, Shinsuke; Taniuchi, Tsutomu; Tomizawa, Hiromitsu; Yanagida, Kenichi

    2005-01-01

    SPring-8 has started its top-up operation from May 2004 in order to feed constant photon fluxes to users. The SPring-8 linac has been improved to realize stable and uninterrupted top-up injection into the SPring-8 storage ring and the NewSUBARU storage ring. The beam energy instability of 0.01% rms had been achieved by the following stabilization: RF amplitude and phase stabilization, synchronization of beam timing and linac's 2856 MHz RF and introduction of an energy compensation system (ECS). Feedback controls of steering magnets compensate long-term variation of beam trajectories at ends of beam transport lines. The presentation will include also recent improvements.

  7. Plasma behavior with hydrogen supersonic molecular beam and cluster jet injection in the HL-2A tokamak

    International Nuclear Information System (INIS)

    The experimental results of low pressure supersonic molecular beam injection (SMBI) into the HL-2A plasma indicated that during the period of SMB pulse injection the power density convected at the divertor target plate surfaces was 0.4 times of that before or after the beam injection. The clusters are produced at nitrogen temperature in a supersonic adiabatic expansion of moderate pressure hydrogen gases into vacuum through a Laval nozzle. The averaged cluster size was measured by Rayleigh scattering as large as hundreds atoms. Multifold diagnostics for the cluster jet injection (CJI) experiments have given a coincident evidence that there was a terminal area where a great deal particles from the clusters deposited at, rather than the clusters uniformly ablating along the injection path. A SMB with large clusters, which are like micro-pellets, was of benefit for deeper fuelling and the fuelling efficiency is distinctly better than that of the room temperature SMBI. Another important effect of the CJI or the high pressure SMBI was that the runaway electrons were cooled down to thermal velocity due to a combination of collision and radiative stopping in such a massive fuelling. So the new fuelling technique may become a good treatment to mitigate fast plasma shutdowns and disruptions. (author)

  8. Direct injection of intense heavy ion beams from a high performance ECR ion source into an RFQ

    International Nuclear Information System (INIS)

    Beam intensities achievable from high performance ECR sources for highly charged ions are limited by the high space charge. For high performance ECR sources, the stray magnetic field of the source can provide focusing against the space charge blow-up of the beam when used with the Direct Plasma Injection Scheme (DPIS) developed for laser ion sources. A combined extraction/matching system has been designed for direct injection into a radio frequency quadrupole (RFQ) accelerator, allowing a total beam current of 12 mA for the production of highly charged 238U40 +(0.49 mA) to be injected at an ion source voltage of 60 kV. In this design, the features of IGUN have been used to take into account the rf-focusing of an RFQ channel (without modulation), the electrostatic field between ionsource extraction and the RFQ vanes, the magnetic stray field of the ECR superconducting solenoid, and the defocusing space charge of the ion beam. The RFQ has been designed to suppress most of the charge states extracted from the ECR, acting as a filter for the desired 238U40+. This reduces the transport problem for the beam line as well as reduces the emittance for the transmitted charge states. Such an rfq-channel might be very effective and less q/m sensitive for the extraction system of all high performing ECR ion sources. This technique has promising applications for injecting and transporting very intense beams into RFQ accelerators for research, ADSS and more efficient, compact neutron generators. The accelerator driven sub-critical system (ADSS) being developed at various laboratories around the world to create nuclear energy may also benefit from this technique, both in terms of transporting intense beams of protons and making the low energy segment more compact. This RFQ is essentially a buncher configured as a charge filter, so RIB facilities can take advantage of this technique. The charge breeding concept can be utilised with a powerful ECR ion source directly coupled to this

  9. High performance operation of negative-ion-based neutral beam injection system for the Large Helical Device

    International Nuclear Information System (INIS)

    It is a touchstone for the success of ITER and future fusion reactor whether the present high performance negative-ion-based NBI (N-NBI) heating systems work properly. The LHD and JT-60U are only two facilities where N-NBI systems are working for high power plasma heating/current drive in the world. Because handling of negative hydrogen/deuterium ions was amateur technology, it has taken a long time to improve its skill. In LHD, we succeeded in improving the performance of one of three beam lines dramatically in 2003 by adopting a multi-slot grounded grid for the accelerator of ion source. The effort on improving the performance was also done in other beam lines with conventional ion sources in parallel. The guidelines of improving are optimization of magnetic multi-cusp configuration for efficient negative ion production, and increasing the transparency of the grounded grid for reduction of heat load on it. As a result the available beam power has been increased, that is, successive injection power level more than 10 MW became possible throughout four-month long experimental campaign, although the maximum injection power has been almost the same. The averaged negative ion beam current density at the exit of ion source, which was evaluated from the port-through injected power, was achieved up to 350 A/m2 which is larger than the required value of ITER NBI in hydrogen beam operation. Pulse length at high beam power level has also been extended owing to the reduction of heat load on the grounded grid. These results (increase in available power and pulse length) have contributed to expand the operation region of LHD. By continuous R and D, we also have found the way of solving an associated problem of multi-slot grounded grid system, that is, mismatched conditions of optimum beam optics in vertical and horizontal directions. According to this result, better beam divergence can be realized, and the increase in the total injection power is expected in the next

  10. Liquid metal alloy ion source based metal ion injection into a room-temperature electron beam ion source.

    Science.gov (United States)

    Thorn, A; Ritter, E; Ullmann, F; Pilz, W; Bischoff, L; Zschornack, G

    2012-02-01

    We have carried out a series of measurements demonstrating the feasibility of using the Dresden electron beam ion source (EBIS)-A, a table-top sized, permanent magnet technology based electron beam ion source, as a charge breeder. Low charged gold ions from an AuGe liquid metal alloy ion source were injected into the EBIS and re-extracted as highly charged ions, thereby producing charge states as high as Au(60 +). The setup, the charge breeding technique, breeding efficiencies as well as acceptance and emittance studies are presented. PMID:22380207

  11. Resonantly excited betatron hard X-Rays from Ionization Injected Electron Beam in a Laser Plasma Accelerator

    CERN Document Server

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

    2015-01-01

    A new scheme for bright hard x-ray emission from laser wakefield electron accelerator is reported, where pure nitrogen gas is adopted. Intense Betatron x-ray beams are generated from ionization injected K-shell electrons of nitrogen into the accelerating wave bucket. The x-ray radiation shows synchrotron-like spectrum with total photon yield 8$\\times$10$^8$/shot and $10^8$ over 110keV. In particular, the betatron hard x-ray photon yield is 10 times higher compared to the case of helium gas under the same laser parameters. Particle-in-cell simulation suggests that the enhancement of the x-ray yield results from ionization injection, which enables the electrons to be quickly accelerated to the driving laser region for subsequent betatron resonance. Employing the present scheme,the single stage nitrogen gas target could be used to generate stable high brightness betatron hard x-ray beams.

  12. Plasma behaviour with hydrogen supersonic molecular beam and cluster jet injection in the HL-2A tokamak

    International Nuclear Information System (INIS)

    The experimental results of low pressure supersonic molecular beam injection (SMBI) fuelling on the HL-2A closed divertor indicate that during the period of pulsed SMBI the power density convected at the target plate surfaces was 0.4 times of that before or after the beam injection. An empirical scaling law used for the SMBI penetration depth for the HL-2A plasma was obtained. The cluster jet injection (CJI) is a new fuelling method which is based on and developed from the experiments of SMBI in the HL-1M tokamak. The hydrogen clusters are produced at liquid nitrogen temperature in a supersonic adiabatic expansion of moderate backing pressure gases into vacuum through a Laval nozzle and are measured by Rayleigh scattering. The measurement results have shown that the averaged cluster size of as large as hundreds of atoms was found at the backing pressures of more than 0.1 MPa. Multifold diagnostics gave coincidental evidence that when there was hydrogen CJI in the HL-2A plasma, a great deal of particles from the jet were deposited at a terminal area rather than uniformly ablated along the injecting path. SMB with clusters, which are like micro-pellets, will be of benefit for deeper fuelling, and its injection behaviour was somewhat similar to that of pellet injection. Both the particle penetration depth and the fuelling efficiency of the CJI were distinctly better than that of the normal SMBI under similar discharge operation. During hydrogen CJI or high-pressure SMBI, a combination of collision and radiative stopping forced the runaway electrons to cool down to thermal velocity due to such a massive fuelling

  13. The effects of neutral beam injection on momentum transport and rotation resulting from reconnection events in a Reversed Field Pinch

    Science.gov (United States)

    Dobbins, T.; Nornberg, M. D.; Anderson, J. K.; den Hartog, D. J.; Reusch, J. A.; Sarff, John; Eilerman, Scott; Craig, Darren

    2012-10-01

    Magnetic reconnection events are characterized by rapid transport that flattens both the plasma current and parallel flow profiles in a RFP. The tangential neutral beam on the MST is a source of momentum injection into the MST that has also been observed to suppress the core-most mode of the plasma. Ensembles of multiple sawtooth events with and without the NBI were performed over a variety of plasma conditions to observe any effects of the NBI on sawtooth crashes. Observations of both mode rotation and impurity emission Doppler shifts show an increase in toroidal rotation associated with the neutral beam. The suppression of the core-most mode was verified for a broader variety of plasmas then before. The mode data also shows that for some plasma parameters the NBI brings a mode into resonance that is not resonant without the NBI. This is the first evidence of the NBI's effect on the plasma current profile. In addition, Co-injection greatly reduces the mode locking, while counter-injection has been shown to slightly increase mode locking.

  14. System for measuring parameters of electron beams injected into collective heavy ion accelerator

    International Nuclear Information System (INIS)

    The description of automation system for measurement of the intensive nanosecond electron beam characteristics of a collective heavy ion accelerator at JINR is presented. The system includes a set of the collector sensors for registering electronics for all sensors. The range of beam measured currents reaches 1000 A at repetition frequency of cycles up to 50 Hz

  15. Resonantly excited betatron hard X-Rays from Ionization Injected Electron Beam in a Laser Plasma Accelerator

    OpenAIRE

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

    2015-01-01

    A new scheme for bright hard x-ray emission from laser wakefield electron accelerator is reported, where pure nitrogen gas is adopted. Intense Betatron x-ray beams are generated from ionization injected K-shell electrons of nitrogen into the accelerating wave bucket. The x-ray radiation shows synchrotron-like spectrum with total photon yield 8$\\times$10$^8$/shot and $10^8$ over 110keV. In particular, the betatron hard x-ray photon yield is 10 times higher compared to the case of helium gas un...

  16. Investigation of the clustering condition for various gasses ejected from a fast solenoid valve for supersonic cluster beam injection

    International Nuclear Information System (INIS)

    The supersonic cluster beam (SSCB) injection method is being developed as a new fueling method for the Large Helical Device (LHD) experiment. As a first step, cluster formation at a room temperature has been investigated for various gasses using a fast solenoid valve for SSCB. Rayleigh scattering of laser light by the cluster is measured by a fast charge coupled device camera. In the case of methane, nitrogen, and argon, clear scattering signals are observed at high valve backing pressure of more than 3-4 MPa. In the case of hydrogen, helium, and neon, on the other hand, no scattering signal is detected at 7 MPa. (author)

  17. MHD Instabilities and Their Effects on Plasma Confinement in Large Helical Device Plasmas with Intense Neutral Beam Injection

    Institute of Scientific and Technical Information of China (English)

    K. Toi; K. Narihara; K. Tanaka; T. Tokuzawa; H. Yamada; Q. Yang; LHD experimental group; S. Ohdachi; S. Yamamoto; S. Sakakibara; K. Y. Watanabe; N. Nakajima; X. Ding; J. Li; S. Morita

    2004-01-01

    MHD stability of the Large Helical Device (LHD) plasmas produced with intense neutral beam injection is experimentally studied. When the steep pressure gradient near the edge is produced through L-H transition or linear density ramp experiment, interchange-like MHD modes whose rational surface is located very close to the last closed flux surface are strongly excited in a certain discharge condition and affect the plasma transport appreciably. In NBI-heated energetic ion loss, but also trigger the formation of internal and edge transport barriers.

  18. Modeling and control of plasma rotation for NSTX using Neoclassical Toroidal Viscosity (NTV) and Neutral Beam Injection (NBI)

    Science.gov (United States)

    Goumiri, Imene; Rowley, Clarence; Sabbagh, Steven; Gates, David; Gerhardt, Stefan

    2014-10-01

    A model-based system to control plasma rotation in a magnetically confined toroidal fusion device is developed to maintain plasma stability for long pulse operation. This research uses experimental measurements from the National Spherical Torus Experiment (NSTX) and is aimed to control plasma rotation by using momentum from injected neutral beams and viscosity generated by three-dimensional applied magnetic fields as actuators. Based on the data driven model obtained, a feedback controller is designed to theoretically sustain the toroidal momentum of the plasma in a stable fashion and to achieve desired plasma rotation profiles. On going work includes extending this method to NSTX Upgrade which has more complete radial coverage of the neutral beams momentum sources which enable simultaneous control of plasma stored energy (Beta control).

  19. Impurity transport during neutral beam injection in the ISX-B tokamak

    International Nuclear Information System (INIS)

    In ohmically heated ISX-B discharges, both the intrinsic iron impurity ions and small amounts of argon introduced as a test gas accumulate at the center of the plasma. But during certain beam-heated discharges, it appears that this accumulation does not take place. These results may reflect the conclusion of Stacey and Sigmar that momentum transferred from the beams to the plasma can inhibit inward impurity transport

  20. Numerical study for beam loss occurring for wide-ranging transverse injection painting and its mitigation scenario in the J-PARC 3-GeV RCS

    International Nuclear Information System (INIS)

    In the J-PARC 3-GeV Rapid Cycling Synchrotron (RCS), transverse injection painting is utilized to manipulate the transverse beam profile according to the requirements from the downstream facilities as well as to mitigate the space-charge induced beam loss in RCS. Therefore, a flexible control is required for the transverse painting area. But now the available range of transverse painting is limited to small area due to beta function beating caused by the edge focus of injection bump magnets which operate during the beam injection period. This beta function beating additionally excites various random betatron resonances through a distortion of the lattice super-periodicity, causing a shrinkage of the dynamic aperture during the injection period. This decrease of the dynamic aperture leads to extra beam loss at present when applying large transverse painting. For beta function beating caused by the edge focus, we proposed a correction scheme with additional pulse-type quadrupole correctors. In this paper, we will discuss the feasibility and effectiveness of this correction scheme for expanding the transverse injection painting area with no extra beam loss, while considering the beam loss and its mitigation mechanisms, based on numerical simulations

  1. Numerical study for beam loss occurring for wide-ranging transverse injection painting and its mitigation scenario in the J-PARC 3-GeV RCS

    Science.gov (United States)

    Hotchi, Hideaki; Tani, Norio; Watanabe, Yasuhiro

    2015-04-01

    In the J-PARC 3-GeV Rapid Cycling Synchrotron (RCS), transverse injection painting is utilized to manipulate the transverse beam profile according to the requirements from the downstream facilities as well as to mitigate the space-charge induced beam loss in RCS. Therefore, a flexible control is required for the transverse painting area. But now the available range of transverse painting is limited to small area due to beta function beating caused by the edge focus of injection bump magnets which operate during the beam injection period. This beta function beating additionally excites various random betatron resonances through a distortion of the lattice super-periodicity, causing a shrinkage of the dynamic aperture during the injection period. This decrease of the dynamic aperture leads to extra beam loss at present when applying large transverse painting. For beta function beating caused by the edge focus, we proposed a correction scheme with additional pulse-type quadrupole correctors. In this paper, we will discuss the feasibility and effectiveness of this correction scheme for expanding the transverse injection painting area with no extra beam loss, while considering the beam loss and its mitigation mechanisms, based on numerical simulations.

  2. ELF oscillations associated with electron beam injections from the space shuttle

    International Nuclear Information System (INIS)

    ELF oscillations (f < 500 Hz) were observed during the electron beam emissions of the space experiments with particle accelerators (SEPAC) flown on the Spacelab 1 shuttle mission. The beams had energies up to 5 keV and currents up to 300 mA, and the oscillations were present in the data from a Langmuir probe, a floating probe, an electron energy analyzer, and a photometer. The VLF (1 kHz < f < 10 kHz) wave stimulation monitored by a wave receiver during one particular beam sequence has already been reported by Neubert et al. (1986). The amplitudes of the ELF and VLF oscillations observed during this sequence have almost identical variations with beam pitch angle, the strongest emissions begin observed for parallel beams; the ELF power spectra for the strongest emissions have peaks about 10 dB above the broadband ELF noise at frequencies aroudn 50-60 Hz. In another beam sequence the power spectra had a harmonic structure with the fundamental frequency around 200 Hz. The power density and frequency of the fundamental increased with the shuttle charge-up potential. The emission level observed during the beam sequences increased with the charge-up potential of the orbiter, which largely depended on the wake structure. The authors find it most likely that the ELF oscillations are expressions of fluctuations in the return current and the shuttle potential and that these fluctuations are caused by processes involving charge imbalances in the near environment of the shuttle, possibly in a comoving plasma cloud. The observations suggest that the plasma cloud has a particle lifetime at least of the order of 100 ms

  3. Beam loading effects during injection processes in an electron storage ring

    International Nuclear Information System (INIS)

    When the current in an electron storage ring increases through the injection process, the RF properties such as the accelerating field, cavity tuning and reflecting power undergo some changes. They must be cancelled out by tuning the RF system in order to get a stable operation. In this report these changes are given in the first order approximation. For the RF storage ring an increment of the current of 25 mA in one injection process brings about no serious effect and a stored current of 500 mA would be obtained in less than 10 minutes. (auth.)

  4. Work function measurements during plasma exposition at conditions relevant in negative ion sources for the ITER neutral beam injection

    Energy Technology Data Exchange (ETDEWEB)

    Gutser, R. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, 85748 Garching (Germany); Wimmer, C. [Lst. f. Experimentelle Plasmaphysik, Universitaet Augsburg, 86135 Augsburg (Germany); Fantz, U. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, 85748 Garching (Germany); Lst. f. Experimentelle Plasmaphysik, Universitaet Augsburg, 86135 Augsburg (Germany)

    2011-02-15

    Cesium seeded sources for surface generated negative hydrogen ions are major components of neutral beam injection systems in future large-scale fusion experiments such as ITER. The stability and delivered current density depend highly on the work function during vacuum and plasma phases of the ion source. One of the most important quantities that affect the source performance is the work function. A modified photocurrent method was developed to measure the temporal behavior of the work function during and after cesium evaporation. The investigation of cesium exposed Mo and MoLa samples under ITER negative hydrogen ion based neutral beam injection relevant surface and plasma conditions showed the influence of impurities which result in a fast degradation when the plasma exposure or the cesium flux onto the sample is stopped. A minimum work function close to that of bulk cesium was obtained under the influence of the plasma exposition, while a significantly higher work function was observed under ITER-like vacuum conditions.

  5. Mixed-DT neutral-beam injection: An alternative heating method for tokamaks

    International Nuclear Information System (INIS)

    In this paper, the authors propose an alternative method for the heating, and perhaps also refueling, of tokamak fusion devices. The alternative method replaces the deuterium neutral-beam injectors (NBIs) such as those now used, for example, on the Tokamak Fusion Test Reactor (TFTR) device. Instead they make use of a mixed (deuterium-tritium) NBI (MNBI) and thereby vastly reduce the cost and complexity of the fuel-recovery cycle. Another like consequence is the reduction of the total amount of tritium in the on-site inventory. The authors suspect that the alternative plant design would have a positive effect on safety, although they have not done an accident analysis based on the mixed-beam injectors. They have, however, studied the requirements of the new fuel cycle and have looked at the question of optimizing some of the parameters associated with a mixed-beam injector. 3 refs

  6. Development of an ion source for long-pulse (30-s) neutral beam injection

    Energy Technology Data Exchange (ETDEWEB)

    Menon, M.M.; Barber, G.C.; Blue, C.W.; Dagenhart, W.K.; Gardner, W.L.; Haselton, H.H.; Moeller, J.A.; Ponte, N.S.; Ryan, P.M.; Schecter, D.E.

    1982-01-01

    This paper describes the development of a long-pulse positive ion source that has been designed to provide high brightness deuterium beams (divergence approx. = 0.25/sup 0/ rms, current density approx. = 0.15 A cm/sup -2/) of 40 to 45 A, at a beam energy of 80 keV, for pulse lengths up to 30 s. The design and construction of the ion source components are described with particular emphasis placed on the long-pulse cathode assembly and ion accelerator.

  7. Cluster effects during high pressure supersonic molecular beam injection into plasma

    International Nuclear Information System (INIS)

    The development of SMBI has experienced for two phases, the first is with low gas pressure source (p0≤0.6 MPa) and the second is with high gas pressure source (p0≥1.0 MPa). In the first phase of SMBI experiment, it is found that SMBI may be a best way for refuelling the HL-1M plasma. In the second phase, the futures of the beam are more evident, especially in the clustering onset, the particles of the beam can penetrate into the center of plasma. The density increase rate of HP-SMB is comparable with small ice PI in the HL-1M tokamak

  8. Performance of magnetically injected plasma opening switches for the Particle Beam Fusion Accelerator 2 (PBFA 2)

    International Nuclear Information System (INIS)

    Plasma opening switch experiments using a magnetically injected plasma have been in progress since October 1988. Plasma densities of 1 x 1012 to 2 x 1013 e/cm3 have been injected from the anode side into the 8 cm gap of the 20 ohm magnetically insulated transmission line of PBFA II using a slowly rising Br,z magnetic field. This field confines the azimuthally-uniform plasma to produce switches up to 30 cm in length. Four MIP geometries have been investigated to find a higher electrical impedance when the switch opens. These studies have shown that a separation of 10 to 20 cm from the load is important to keep the POS from affecting the load performance. With such a separation, 20 to 30 TW of power at 7 to 11 MV has been delivered to electron and ion diode loads. Data on switch performance with various loads and factors that improve performance are discussed. 4 refs., 6 figs

  9. Generation of High Brightness Electron Beams via Ionization Induced Injection by Transverse Colliding Lasers in a Beam-Driven Plasma Wakefield Accelerator

    CERN Document Server

    Li, F; Xu, X L; Zhang, C J; Yan, L X; Du, Y C; Huang, W H; Cheng, H B; Tang, C X; Lu, W; Joshi, C; Mori, W B; Gu, Y Q

    2013-01-01

    The production of ultra-bright electron bunches using ionization injection triggered by two transversely colliding laser pulses inside a beam-driven plasma wake is examined via three-dimensional (3D) particle-in-cell (PIC) simulations. The relatively low intensity lasers are polarized along the wake axis and overlap with the wake for a very short time. The result is that the residual momentum of the ionized electrons in the transverse plane of the wake is much reduced and the injection is localized along the propagation axis of the wake. This minimizes both the initial 'thermal' emittance and the emittance growth due to transverse phase mixing. 3D PIC simulations show that ultra-short (around 8 fs) high-current (0.4 kA) electron bunches with a normalized emittance of 8.5 and 6 nm in the two planes respectively and a brightness greater than 1.7*10e19 A rad-2 m-2 can be obtained for realistic parameters.

  10. The influence of Laval nozzle throat size on supersonic molecular beam injection

    Institute of Scientific and Technical Information of China (English)

    Xinkui He; Xianfu Feng; Mingmin Zhong; Fujun Gou; Shuiquan Deng; Yong Zhao

    2014-01-01

    In this study, finite element analysis (FEA) has been used to investigate the effects of different Laval nozzle throat sizes on supersonic molecular beam. The simulations indicate the Mach numbers of the molecular stream peak at different positions along the center axis of the beam, which correspond to local minimums of the molecular densities. With the increase of the throat diam-eter, the first peak of the Mach number increases first and then decreases, while that of the molecular number density increases gradually. Moreover, both first peaks shift pro-gressively away from the throat. At the last part, we discuss the possible applications of our FEA approach to solve some crucial problems met in modern transportations.

  11. Microwave plasma source for neutral-beam injection systems. Quarterly technical progress report

    International Nuclear Information System (INIS)

    The overall program is described and the technical and programmatic reasons for the decision to pursue both the RFI and ECH sources into the current hydrogen test stage is discussed. We consider the general characteristics of plasma sources in the parameter regime of interest for neutral beam applications. The operatonal characteristics, advantages and potential problems of RFI and ECH sources are discussed. In these latter two sections we rely heavily on experience derived from developing RFI and ECH ion engine sources for NASA

  12. Specific features of measuring the isotopic composition of hydrogen ions in ITER plasma by using neutral particle diagnostics under neutral beam injection conditions

    Energy Technology Data Exchange (ETDEWEB)

    Afanasyev, V. I. [Russian Academy of Sciences, Ioffe Physical Technical Institute (Russian Federation); Goncharov, P. R., E-mail: p.goncharov@spbstu.ru [Peter the Great St. Petersburg Polytechnic University (Russian Federation); Mironov, M. I.; Nesenevich, V. G., E-mail: vnesenevich@npd.ioffe.ru; Petrov, M. P.; Petrov, S. Ya. [Russian Academy of Sciences, Ioffe Physical Technical Institute (Russian Federation); Sergeev, V. Yu. [Peter the Great St. Petersburg Polytechnic University (Russian Federation)

    2015-12-15

    Results of numerical simulation of signals from neutral particle analyzers under injection of the heating and diagnostic neutral beams in different operating modes of the ITER tokamak are presented. The distribution functions of fast ions in plasma are simulated, and the corresponding neutral particle fluxes escaping from the plasma along the line of sight of the analyzers are calculated. It is shown that the injection of heating deuterium (D{sup 0}) beams results in the appearance of an intense background signal hampering measurements of the ratio between the densities of deuterium and tritium fuel ions in plasma in the thermal energy range. The injection of a diagnostic hydrogen (H{sup 0}) beam does not affect measurements owing to the high mass resolution of the analyzers.

  13. Electron gun with off-axis beam injection for a race-track microtron

    International Nuclear Information System (INIS)

    A miniature 12 MeV race-track microtron for medical applications is under construction at the Technical University of Catalonia in collaboration with several Spanish centers and companies and the Skobeltsyn Institute of Nuclear Physics of the Moscow State University. As a source of electrons a compact 3D on-axis electron gun with an off-axis cathode has been designed to allow a direct and efficient injection into the accelerating structure. Its prototype has been built and successfully tested. Results of the electron gun design simulations and of the prototype performance are herein described.

  14. DIII-D Quiescent H-Mode Experiments With Co Plus Counter Neutral Beam Injection

    Science.gov (United States)

    Burrell, K. H.; West, W. P.; Gohil, P.; Groebner, R. J.; Snyder, P. B.; Fenstermacher, M. E.; Lasnier, C. J.; Solomon, W. M.

    2006-10-01

    In many ways, quiescent H-modes are the ideal H-mode plasma. They exhibit H-mode confinement for long duration (>4 s or 30 τE) with constant density and radiated power. The absence of edge localized modes (ELMs) means no pulsed divertor heat loads. The quiescent edge is also quite compatible with core transport barriers. To utilize QH-mode in future devices, the goals of our recent QH-mode experiments are to develop an improved physics understanding of the QH-mode, especially the ELM stabilization, and to broaden the QH-mode operating space. During the 2006 campaign, we utilized DIII-D's new co plus counter NBI capability to determine how much counter injection is necessary for QH-mode operation. As plasma triangularity is increased, increasing amounts of co-injection can be used while still maintaining the quiescent state. This is consistent with expectations based on peeling-ballooning mode theory. Further experiments are planned to explore the co-counter boundary more thoroughly.

  15. Magnetic Configuration Effects Under Neutral Beam Injection at TJ-II

    International Nuclear Information System (INIS)

    The theoretical analysis of NBI absorption and losses, done for the Reference configuration of TJ-II, has been extended to other magnetic configurations of the flexibility diagram. The main results obtained are the following: Fast ion losses. mainly direct ones, are the determinant factor the absorption behaviour. In the absence of radial electric field, the contribution of the delayed fast ion losses in minimal, as well with CX as without, and corresponds, almost exclusively, to low energy trapped ions (1 to t KeV). There is a strong difference between the direct los behaviour corresponding to both injection directions CO and COUNTER. The first one gives always higher losses in TJ-II. For the extreme configurations the direct losses are very high and are originated by resonant effects, that can be observed even for null electric field, and are due to the 0 and-2 resonances. The intermediate configurations are equally separated from both resonances, in consequence the loss level is lower, producing absorption ratios very, acceptable, higher than 60% of the power entering torus at high density and 40 keV. This corresponds to about 1.2 MW absorbed in plasma under balanced injection. In conclusion, the possible presence of resonant effects on the direct losses is the key element to explain the absorption behaviour for the different magnetic configurations. In addition all the configurations placed inside a wide region around the Reference case in the flexibility diagram seem equally convenient for NBI in TJ-II. (Author) 18 refs

  16. Edge localized mode characteristics during edge localized mode mitigation by supersonic molecular beam injection in Korea Superconducting Tokamak Advanced Research

    International Nuclear Information System (INIS)

    It has been reported that supersonic molecular beam injection (SMBI) is an effective means of edge localized mode (ELM) mitigation. This paper newly reports the changes in the ELM, plasma profiles, and fluctuation characteristics during ELM mitigation by SMBI in Korea Superconducting Tokamak Advanced Research. During the mitigated ELM phase, the ELM frequency increased by a factor of 2–3 and the ELM size, which was estimated from the Dα amplitude, the fractional changes in the plasma-stored energy and the line-averaged electron density, and divertor heat flux during an ELM burst, decreased by a factor of 0.34–0.43. Reductions in the electron and ion temperatures rather than in the electron density were observed during the mitigated ELM phase. In the natural ELM phase, frequency chirping of the plasma fluctuations was observed before the ELM bursts; however, the ELM bursts occurred without changes in the plasma fluctuation frequency in the mitigated ELM phase

  17. Observation of edge filamentary structure motion during supersonic molecular-beam injection using a fast camera in Heliotron J

    International Nuclear Information System (INIS)

    A perpendicular-view fast video camera has been installed in Heliotron J to observe the behavior of filamentary structures of edge plasma turbulence across the last closed flux surface (LCFS). Supersonic molecular-beam injection (SMBI) can greatly increase the edge Hα emission; hence, we used the high imaging rate and shutter speed of the camera to capture the behavior of the fast propagating filamentary structures. A high-pass fast Fourier transform filter on the time dimension was adopted to extract the fluctuation component from the raw data for each pixel. The motion of the filamentary structures was clearly visible when we applied an amplitude threshold to identify the intense structures. In addition, a time-resolved 2D cross-correlation technique was adopted to estimate the poloidal phase velocity of turbulence. The motion direction was found to be reversed dramatically just after an SMBI pulse. (author)

  18. Injectable silver nanosensors: in vivo dosimetry for external beam radiotherapy using positron emission tomography

    Science.gov (United States)

    Christensen, A. N.; Rydhög, J. S.; Søndergaard, R. V.; Andresen, T. L.; Holm, S.; Munck Af Rosenschöld, P.; Conradsen, K.; Jølck, R. I.

    2016-05-01

    Development of safe and efficient radiotherapy routines requires quantification of the delivered absorbed dose to the cancer tissue in individual patients. In vivo dosimetry can provide accurate information about the absorbed dose delivered during treatment. In the current study, a novel silver-nanosensor formulation based on poly(vinylpyrrolidinone)-coated silver nanoparticles formulated in a gelation matrix composed of sucrose acetate isobutyrate has been developed for use as an in vivo dosimeter for external beam radiotherapy. In situ photonuclear reactions trigger the formation of radioactive 106Ag, which enables post treatment verification of the delivered dose using positron emission tomography imaging. The silver-nanosensor was investigated in a tissue equivalent thorax phantom using clinical settings and workflow for both standard fractionated radiotherapy (2 Gy) and stereotactic radiotherapy (10- and 22 Gy) in a high-energy beam setting (18 MV). The developed silver-nanosensor provided high radiopacity on the planning CT-scans sufficient for patient positioning in image-guided radiotherapy and provided dosimetric information about the absorbed dose with a 10% and 8% standard deviation for the stereotactic regimens, 10 and 22 Gy, respectively.Development of safe and efficient radiotherapy routines requires quantification of the delivered absorbed dose to the cancer tissue in individual patients. In vivo dosimetry can provide accurate information about the absorbed dose delivered during treatment. In the current study, a novel silver-nanosensor formulation based on poly(vinylpyrrolidinone)-coated silver nanoparticles formulated in a gelation matrix composed of sucrose acetate isobutyrate has been developed for use as an in vivo dosimeter for external beam radiotherapy. In situ photonuclear reactions trigger the formation of radioactive 106Ag, which enables post treatment verification of the delivered dose using positron emission tomography imaging. The

  19. Injectable silver nanosensors: in vivo dosimetry for external beam radiotherapy using positron emission tomography.

    Science.gov (United States)

    Christensen, A N; Rydhög, J S; Søndergaard, R V; Andresen, T L; Holm, S; Munck Af Rosenschöld, P; Conradsen, K; Jølck, R I

    2016-06-01

    Development of safe and efficient radiotherapy routines requires quantification of the delivered absorbed dose to the cancer tissue in individual patients. In vivo dosimetry can provide accurate information about the absorbed dose delivered during treatment. In the current study, a novel silver-nanosensor formulation based on poly(vinylpyrrolidinone)-coated silver nanoparticles formulated in a gelation matrix composed of sucrose acetate isobutyrate has been developed for use as an in vivo dosimeter for external beam radiotherapy. In situ photonuclear reactions trigger the formation of radioactive (106)Ag, which enables post treatment verification of the delivered dose using positron emission tomography imaging. The silver-nanosensor was investigated in a tissue equivalent thorax phantom using clinical settings and workflow for both standard fractionated radiotherapy (2 Gy) and stereotactic radiotherapy (10- and 22 Gy) in a high-energy beam setting (18 MV). The developed silver-nanosensor provided high radiopacity on the planning CT-scans sufficient for patient positioning in image-guided radiotherapy and provided dosimetric information about the absorbed dose with a 10% and 8% standard deviation for the stereotactic regimens, 10 and 22 Gy, respectively. PMID:27174233

  20. A method of particle transport study using supersonic molecular beam injection and microwave reflectometry on HL-2A tokamak

    International Nuclear Information System (INIS)

    A method of the particle transport study using supersonic molecular beam injection (SMBI) and microwave reflectometry is reported in this paper. Experimental results confirm that pulsed SMBI is a good perturbation source with deeper penetration and better localization than the standard gas puffing. The local density modulation is induced using the pulsed SMBI and the perturbation density is measured by the microwave reflectometry. Using Fourier transform analysis for the local density perturbation, radial profiles of the amplitude and phase of the density modulation can be obtained. The experimental results in HL-2A show that the particle injected by SMBI is located at about r/a=0.65-0.75. The position of the main particle source can be determined through three aspects: the minimum of the phase of the first harmonic of the Fourier transform of the modulated density measured by microwave reflectometry; the Ha intensity profile and the local density increase ratio. The maximum of the amplitude of the first harmonic shifts often inward relative to the particle source location, which indicates clearly there is an inward particle pinch in this area. Good agreement has been found between the experimental results and the simulation using analytical transport model. The particle diffusivity D and the particle convection velocity V have been obtained by doing this simulation. The sensitivity in the transport coefficients of the amplitude and the phase of the density modulation has been discussed.

  1. Magnetic configuration effects on plasma transport under Neutral Beam Injection at TJ-II (Simulation)

    International Nuclear Information System (INIS)

    A systematic analysis of magnetic configurations (27 in total), using a Transport model including impurity dynamics and sputtering effects has been done. For small size configurations or those close to rational t values there is radioactive collapse, independently of the external gas puffing (GP) strategy chosen. The reason is the insufficiency of observed power, either by the high shine through losses due to their low radii, or by the increase of fast ion orbit losses near the resonances. For the majority of configurations without collapse, fast ion orbit losses for CO injection (going in the same direction than the toroidal magnetic field) are higher, and in consequence the power absorption and the plasma β achieved are laser, than for the opposite direction. Nevertheless in the region placed just above the main resonances (1/3 and 1/2 per period) this situation reverses. The reasons have been analysed and explained at previous studies. A consequence of this fact is that the optima of confinement for the Counter case are shifted towards higher t values than the CO one, with higher plasma β, except near the resonances. As usual the balanced case is in between. The optima achieving stationary state are very close (and often are coincident) with those lacking that restriction. The best configuration (highest average β for balanced injection, with =1.1% and central value 3.2%, although in this region the results are rather insensitive to configuration and GP strategy. the configurations placed around the 10044 would need also the lowest power entering the torus in order to avoid collapse and to achieve an acceptable NBI absorption level. (Author) 12 refs

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

    Science.gov (United States)

    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.

  3. Numerical Simulation of Subcooled Boiling Inside High-Heat-Flux Component with Swirl Tube in Neutral Beam Injection System

    International Nuclear Information System (INIS)

    In order to realize steady-state operation of the neutral beam injection (NBI) system with high beam energy, an accurate thermal analysis and a prediction about working conditions of heat-removal structures inside high-heat-flux (HHF) components in the system are key issues. In this paper, taking the HHF ion dump with swirl tubes in NBI system as an example, an accurate thermal dynamic simulation method based on computational fluid dynamics (CFD) and the finite volume method is presented to predict performance of the HHF component. In this simulation method, the Eulerian multiphase method together with some empirical corrections about the inter-phase transfer model and the wall heat flux partitioning model are considered to describe the subcooled boiling. The reliability of the proposed method is validated by an experimental example with subcooled boiling inside swirl tube. The proposed method provides an important tool for the refined thermal and flow dynamic analysis of HHF components, and can be extended to study the thermal design of other complex HHF engineering structures in a straightforward way. The simulation results also verify that the swirl tube is a promising heat removing structure for the HHF components of the NBI system. (fusion engineering)

  4. Thermal loads on the TJ-II Vacuum Vessel under Neutral Beam Injection

    International Nuclear Information System (INIS)

    In this study a numerical analysis of power loads on the complex 3D structure of the TJ-II Vacuum Vessel, moderated with reasonable accuracy, under NBI, is done. To do this it has been necessary to modify deeply the DENSB code for power loads in order to include the TJ-II VV wall parts as targets and as beam scrapers, allowing the possibility of self-shadowing. After a short description of the primitive version of the DENSB code (paragraph 2) and of the visualisation code MOVIE(paragraph 3), the DENSB upgrading are described (paragraphs 4,5) and finally the results are presented (paragraph 6). These code modifications and the improving on the visualization tools provide more realistic load evaluations, both with and without plasma, validating former results and showing clearly the VV zones that will need new protections. (Author)

  5. VLF wave stimulation by pulsed electron beams injected from the Space Shuttle

    Science.gov (United States)

    Reeves, G. D.; Banks, P. M.; Frazer-Smith, A. C.; Neubert, T.; Bush, R. I.

    1988-01-01

    Among the investigations conducted on the Space Shuttle flight STS-3 of March 1982 was an experiment in which a 1-keV, 100-mA electron gun was pulsed at 3.25 and 4.87 kHz. The resultant waves were measured with a broadband plasma wave receiver. At the time of flight the experimental setup was unique in that the electron beam was square wave modulated and that the Shuttle offered relatively long times for in situ measurements of the ionospheric plasma response to the VLF pulsing sequences. In addition to electromagnetic response at the pulsing frequencies the wave exhibited various spectral harmonics as well as the unexpected occurrence of 'satellite lines' around those harmonics. Both phenomena occurred with a variety of different characteristics for different pulsing sequences.

  6. Modeling of Synergy Between 4th and 6th Harmonic Absorptions of Fast Waves on Injected Beams in DIII-D Tokamak

    International Nuclear Information System (INIS)

    In recent moderate to high harmonic fast wave heating and current drive experiments in DIII-D, a synergy effect was observed when the 6th harmonic 90 MHz fast wave power is applied to the plasma preheated by neutral beams and the 4th harmonic 60 MHz fast wave. In this paper, we investigate how the synergy can occur using ORBIT-RF coupled with AORSA. Preliminary simulations suggest that damping of 4th harmonic FW on beam ions accelerates them above the injection energy, which may allow significant damping of 6th harmonic FW on beam ion tails to produce synergy.

  7. Heavy Inertial Confinement Energy: Interactions Involoving Low charge State Heavy Ion Injection Beams

    Energy Technology Data Exchange (ETDEWEB)

    DuBois, Robert D

    2006-04-14

    During the contract period, absolute cross sections for projectile ionization, and in some cases for target ionization, were measured for energetic (MeV/u) low-charge-state heavy ions interacting with gases typically found in high and ultra-high vacuum environments. This information is of interest to high-energy-density research projects as inelastic interactions with background gases can lead to serious detrimental effects when intense ion beams are accelerated to high energies, transported and possibly confined in storage rings. Thus this research impacts research and design parameters associated with projects such as the Heavy Ion Fusion Project, the High Current and Integrated Beam Experiments in the USA and the accelerator upgrade at GSI-Darmstadt, Germany. Via collaborative studies performed at GSI-Darmstadt, at the University of East Carolina, and Texas A&M University, absolute cross sections were measured for a series of collision systems using MeV/u heavy ions possessing most, or nearly all, of their bound electrons, e.g., 1.4 MeV/u Ar{sup +}, Xe{sup 3+}, and U{sup 4,6,10+}. Interactions involving such low-charge-state heavy ions at such high energies had never been previously explored. Using these, and data taken from the literature, an empirical model was developed for extrapolation to much higher energies. In order to extend our measurements to much higher energies, the gas target at the Experimental Storage Ring in GSI-Darmstadt was used. Cross sections were measured between 20 and 50 MeV/u for U{sup 28+}- H{sub 2} and - N{sub 2}, the primary components found in high and ultra-high vacuum systems. Storage lifetime measurements, information inversely proportional to the cross section, were performed up to 180 MeV/u. The lifetime and cross section data test various theoretical approaches used to calculate cross sections for many-electron systems. Various high energy density research projects directly benefit by this information. As a result, the general

  8. Evidence for high-energy and low-emittance electron beams using ionization injection of charge in a plasma wakefield accelerator

    CERN Document Server

    Vafaei-Najafabadi, N; Clayton, C E; Joshi, C; Marsh, K A; Mori, W B; Welch, E C; Lu, W; Adli, E; Allen, J; Clarke, C I; Corde, S; Frederico, J; Gessner, S J; Green, S Z; Hogan, M J; Litos, M D; Yakimenko, V

    2015-01-01

    Ionization injection in a plasma wakefield accelerator was investigated experimentally using two lithium plasma sources of different lengths. The ionization of the helium gas, used to confine the lithium, injects electrons in the wake. After acceleration, these injected electrons were observed as a distinct group from the drive beam on the energy spectrometer. They typically have a charge of tens of pC, an energy spread of a few GeV, and a maximum energy of up to 30 GeV. The emittance of this group of electrons can be many times smaller than the initial emittance of the drive beam. The energy scaling for the trapped charge from one plasma length to the other is consistent with the blowout theory of the plasma wakefield.

  9. Cadmium and lead determination in foods by beam injection flame furnace atomic absorption spectrometry after ultrasound-assisted sample preparation

    International Nuclear Information System (INIS)

    A simple method for cadmium and lead determination in foods by beam injection flame furnace atomic absorption spectrometry (BIFF-AAS) was proposed. Food slurries were prepared by transferring an exact amount of cryogenic-ground homogenized material (50-100 mg) to centrifuge tubes, followed by addition of 5 ml (up to 2.8 mol l-1) nitric acid solution and sonication in an ultrasonic bath during 5-10 min. Thereafter, slurries were diluted with water to 10 ml, centrifuged during 5 min at 5400 rpm and 400 μl aliquot of the supernatant was analyzed by BIFF-AAS. The detection limits based on peak height measurements were 0.03 μg g-1 Cd and 1.6 μg g-1 Pb for 2% (m/v) slurry (200 mg/10 ml). For method validation, the certified reference materials Pig Kidney (BCR 186) and Rice Flour (NIES 10) were used. Quantitative cadmium and lead recoveries were obtained and no statistical differences were found at 95% level by applying the t-test

  10. Edge localized mode characteristics during edge localized mode mitigation by supersonic molecular beam injection in Korea Superconducting Tokamak Advanced Research

    Energy Technology Data Exchange (ETDEWEB)

    Lee, H. Y.; Hong, J. H.; Jang, J. H.; Park, J. S.; Choe, Wonho, E-mail: wchoe@kaist.ac.kr [Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), 34141 Daejeon (Korea, Republic of); Impurity and Edge Plasma Research Center, KAIST, 34141 Daejeon (Korea, Republic of); Hahn, S. H.; Bak, J. G.; Lee, J. H.; Ko, W. H.; Lee, K. D.; Lee, S. H.; Lee, H. H.; Juhn, J.-W.; Kim, H. S.; Yoon, S. W.; Han, H. [National Fusion Research Institute, 34133 Daejeon (Korea, Republic of); Ghim, Y.-C. [Deparment of Nuclear and Quantum Engineering, KAIST, 34141 Daejeon (Korea, Republic of)

    2015-12-15

    It has been reported that supersonic molecular beam injection (SMBI) is an effective means of edge localized mode (ELM) mitigation. This paper newly reports the changes in the ELM, plasma profiles, and fluctuation characteristics during ELM mitigation by SMBI in Korea Superconducting Tokamak Advanced Research. During the mitigated ELM phase, the ELM frequency increased by a factor of 2–3 and the ELM size, which was estimated from the D{sub α} amplitude, the fractional changes in the plasma-stored energy and the line-averaged electron density, and divertor heat flux during an ELM burst, decreased by a factor of 0.34–0.43. Reductions in the electron and ion temperatures rather than in the electron density were observed during the mitigated ELM phase. In the natural ELM phase, frequency chirping of the plasma fluctuations was observed before the ELM bursts; however, the ELM bursts occurred without changes in the plasma fluctuation frequency in the mitigated ELM phase.

  11. Charge injection properties of iridium oxide films produced on Ti-6Al-4V alloy substrates by ion-beam mixing techniques

    Energy Technology Data Exchange (ETDEWEB)

    Williams, J.M. (Oak Ridge National Lab., TN (United States)); Lee, I-S.; Buchanan, R.A. (Tennessee Univ., Knoxville, TN (United States))

    1991-10-01

    The charge injection capabilities of iridium oxide films, as produced on Ti6Al-4V alloy substrates by ion beam mixing techniques, have been investigated. Iridium oxide is a valence change oxide, and therefore has high values of charge injection density upon voltage cycling in electrolytes. Because of this property, iridium oxide films are useful as working elements in neural prostheses. Iridium films of three thicknesses, produced by sputter deposition followed by ion beam mixing, were tested in cyclic voltammetry out to 1000 cycles or more. Two surface preparations, mechanical polishing and an acid passivation treatment, were also used as controls. Surface analysis was primarily by Rutherford backscattering spectrometry. Both the ion- beam mixing and the acid pretreatment increased the lifetimes of films, in comparison with the mechanically polished standards. Reductions in charge injection capability, when they occurred, were attributed to loss of Ir from the films, and there was a close correlation between the charge injection density and the Ir inventory. 13 refs., 5 figs.

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

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, Carl [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Benedetti, Carlo [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Bulanov, Stepan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Chen, Min [Shanghai Jiao Tong Univ. (China); Esarey, Eric [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Geddes, Cameron [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Vay, J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Yu, Lule [Shanghai Jiao Tong Univ. (China); Leemans, Wim [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    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.

  13. The direct injection of intense ion beams from a high field electron cyclotron resonance ion source into a radio frequency quadrupole

    International Nuclear Information System (INIS)

    The ion current achievable from high intensity ECR sources for highly charged ions is limited by the high space charge. This makes classical extraction systems for the transport and subsequent matching to a radio frequency quadrupole (RFQ) accelerator less efficient. The direct plasma injection (DPI) method developed originally for the laser ion source avoids these problems and uses the combined focusing of the gap between the ion source and the RFQ vanes (or rods) and the focusing of the rf fields from the RFQ penetrating into this gap. For high performance ECR sources that use superconducting solenoids, the stray magnetic field of the source in addition to the DPI scheme provides focusing against the space charge blow-up of the beam. A combined extraction/matching system has been designed for a high performance ECR ion source injecting into an RFQ, allowing a total beam current of 10 mA from the ion source for the production of highly charged 238U40+ (1.33 mA) to be injected at an ion source voltage of 60 kV. In this design, the features of IGUN have been used to take into account the rf-focusing of an RFQ channel (without modulation), the electrostatic field between ion source extraction and the RFQ vanes, the magnetic stray field of the ECR superconducting solenoid, and the defocusing space charge of an ion beam. The stray magnetic field is shown to be critical in the case of a matched beam

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

    International Nuclear Information System (INIS)

    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.

  15. The direct injection of intense ion beams from a high field electron cyclotron resonance ion source into a radio frequency quadrupole.

    Science.gov (United States)

    Rodrigues, G; Becker, R; Hamm, R W; Baskaran, R; Kanjilal, D; Roy, A

    2014-02-01

    The ion current achievable from high intensity ECR sources for highly charged ions is limited by the high space charge. This makes classical extraction systems for the transport and subsequent matching to a radio frequency quadrupole (RFQ) accelerator less efficient. The direct plasma injection (DPI) method developed originally for the laser ion source avoids these problems and uses the combined focusing of the gap between the ion source and the RFQ vanes (or rods) and the focusing of the rf fields from the RFQ penetrating into this gap. For high performance ECR sources that use superconducting solenoids, the stray magnetic field of the source in addition to the DPI scheme provides focusing against the space charge blow-up of the beam. A combined extraction/matching system has been designed for a high performance ECR ion source injecting into an RFQ, allowing a total beam current of 10 mA from the ion source for the production of highly charged (238)U(40+) (1.33 mA) to be injected at an ion source voltage of 60 kV. In this design, the features of IGUN have been used to take into account the rf-focusing of an RFQ channel (without modulation), the electrostatic field between ion source extraction and the RFQ vanes, the magnetic stray field of the ECR superconducting solenoid, and the defocusing space charge of an ion beam. The stray magnetic field is shown to be critical in the case of a matched beam. PMID:24593474

  16. The direct injection of intense ion beams from a high field electron cyclotron resonance ion source into a radio frequency quadrupole

    Science.gov (United States)

    Rodrigues, G.; Becker, R.; Hamm, R. W.; Baskaran, R.; Kanjilal, D.; Roy, A.

    2014-02-01

    The ion current achievable from high intensity ECR sources for highly charged ions is limited by the high space charge. This makes classical extraction systems for the transport and subsequent matching to a radio frequency quadrupole (RFQ) accelerator less efficient. The direct plasma injection (DPI) method developed originally for the laser ion source avoids these problems and uses the combined focusing of the gap between the ion source and the RFQ vanes (or rods) and the focusing of the rf fields from the RFQ penetrating into this gap. For high performance ECR sources that use superconducting solenoids, the stray magnetic field of the source in addition to the DPI scheme provides focusing against the space charge blow-up of the beam. A combined extraction/matching system has been designed for a high performance ECR ion source injecting into an RFQ, allowing a total beam current of 10 mA from the ion source for the production of highly charged 238U40+ (1.33 mA) to be injected at an ion source voltage of 60 kV. In this design, the features of IGUN have been used to take into account the rf-focusing of an RFQ channel (without modulation), the electrostatic field between ion source extraction and the RFQ vanes, the magnetic stray field of the ECR superconducting solenoid, and the defocusing space charge of an ion beam. The stray magnetic field is shown to be critical in the case of a matched beam.

  17. Detailed magnetic model simulations of the H- injection chicane magnets for the CERN PS Booster Upgrade, including eddy currents and influence on beam dynamics

    CERN Document Server

    Benedetto, E; Borburgh, J; Carli, C; Martini, M; Forte, V

    2014-01-01

    The CERN PS Booster will be upgraded with an H- injection system. The chicanemagnets for the injection bump ramp-down in 5 ms and generate eddy currents in the inconel vacuum chamber which perturb the homogeneity of the magnetic field. The multipolar field components are extracted from 3D OPERA simulations and are included in the lattice model. The -beating correction is computed all along the ramp and complete tracking simulations including space-charge are performed to evaluate the impact of these perturbations and correction on beam dynamics.

  18. Dose rate estimates in the first optical enclosure due to particle beam loss in the insertion device transition region during injection

    International Nuclear Information System (INIS)

    The particle beam, during injection into the storage ring, can be partly lost in one of the transition regions between the storage-ring vacuum chamber and the insertion-device (ID) straight section. The transition region is a copper interface between a standard aluminum vacuum chamber and an insertion-device vacuum chamber. This can be a problem, at least in the first few insertion devices where the injected beam is still unstable. It may create higher photon and neutron dose rates in the first optical enclosures of the upstream ID beamlines adjacent to this region. This report presents the results of the dose rate estimates for such an event and some recommendations for mitigation

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

    CERN Document Server

    Schroeder, C B; Bulanov, S S; Chen, M; Esarey, E; Geddes, C G R; Vay, J -L; Yu, L -L; Leemans, W P

    2015-01-01

    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:Al2...

  20. Design, fabrication and VNA testing of an auto-focussing buncher section for 40 keV, 500 mA DC electron beam injection

    International Nuclear Information System (INIS)

    A buncher section for the 40 keV, DC electron beam has been designed in such a way so that it will act as a buncher and focuser to the injected electron beam. The autofocussing effect is obtained by introducing a slow rise of the Eacc in the first buncher cell. The RF phase focusing force is proportional to the factor (βγ2)-1 and it damps out very quickly as the particle becomes relativistic. Taking this dependency into account, the field asymmetry is introduced only in the first bunching cavity. This paper presents the electromagnetic (EM) design of the RF structure, beam dynamics, fabrication and the measurements of the EM parameters with VNA. (author)

  1. Quasi-monoenergetic Electron Beams from Laser-plasma Acceleration by Ionization-induced Injection in Low- density Pure Nitrogen

    OpenAIRE

    Tao, Mengze; Hafz, Nasr A. M.; Li, Song; Mirzaie, Mohammad; Chen, Liming; He, Fei; Cheng, Ya; Jie ZHANG

    2014-01-01

    We report a laser wakefield acceleration of electron beams up to 130 MeV from laser-driven 4-mm long nitrogen gas jet. By using a moderate laser intensity (3.5*10^18 W.cm^(-2)) and relatively low plasma densities (0.8*10^18 cm^(-3) to 2.7*10^18 cm^(-3)) we have achieved a stable regime for laser propagation and consequently a stable generation of electron beams. We experimentally studied the dependence of the drive laser energy on the laser-plasma channel and electron beam parameters. The qua...

  2. Grating spectrometer system for beam emission spectroscopy diagnostics using high-energy negative-ion-based neutral beam injection on LHD

    International Nuclear Information System (INIS)

    A beam emission spectroscopy (BES) system was developed for density gradient and fluctuation diagnostics in the Large Helical Device (LHD). In order to cover the large Doppler shift of the Hα beam emission because of the high-energy negative-ion-based neutral beam atom (acceleration voltage Vacc=90-170 kV) and the large motional Stark splitting due to the large vxB field (magnetic field B=3.0 T), a grating spectrometer was used instead of a conventional interference filter system. The reciprocal linear dispersion is about 2 nm/mm, which is sufficient to cover the motional Stark effect spectra using an optical fiber with a diameter of 1 mm.

  3. Modeling and control of plasma rotation and βn for NSTX-U using Neoclassical Toroidal Viscosity and Neutral Beam Injection

    Science.gov (United States)

    Goumiri, Imene; Rowley, Clarence; Sabbagh, Steven; Gates, David; Gerhardt, Stefan; Boyer, Mark

    2015-11-01

    A model-based system is presented allowing control of the plasma rotation profile in a magnetically confined toroidal fusion device to maintain plasma stability for long pulse operation. The analysis, using NSTX data and NSTX-U TRANSP simulations, is aimed at controlling plasma rotation using momentum from six injected neutral beams and neoclassical toroidal viscosity generated by three-dimensional applied magnetic fields as actuators. Based on the momentum diffusion and torque balance model obtained, a feedback controller is designed and predictive simulations using TRANSP will be presented. Robustness of the model and the rotation controller will be discussed.

  4. Experimental study of the dependence of beam current on injection magnetic field in 6.4 GHz ECR ion source

    Indian Academy of Sciences (India)

    G S Taki; P R Sarma; D K Chakraborty; R K Bhandari; P K Ray

    2006-09-01

    The ion current from an electron cyclotron resonance (ECR) heavy ion source depends on the confining axial and radial magnetic fields. Some efforts were made by earlier workers to investigate magnetic field scaling on the performance of the ECR source. In order to study the dependence of the ion current on the injection magnetic field in the 6.4 GHz ECR source, we have measured the current by varying the peak injection field and have inferred that the variation of the current is exponential up to our maximum design injection field of 7.5 kG. An attempt has been made to understand this exponential nature on the basis of ion confinement time.

  5. Impurity Dynamics under Neutral Beam Injection at TJ-II (simulation); Dinamica de Impurezas durante la Inyeccion de Haces Neutros en el TJ-II (simulacion)

    Energy Technology Data Exchange (ETDEWEB)

    Guasp, J.; Fuentes, C.; Liniers, M.

    2001-07-01

    In this study the simulations of plasma transport under NBI for TJ-II, previously performed, are extended. Since than a considerable number of important modifications have been introduced in the model: change of magnetic configuration, use of experimental initial profiles, expansion of the Data base from NBI calculations and, mainly, a detailed handling of impurities with inclusion of sputtering effects. Moreover there is now a particular emphasis on the analysis of the conditions for discharge collapse and on the possible effects of single beam injection. This analysis of impurity behaviour with sputtering shows that in the expected usual cases there is no radioactive collapse and that if the recycling coefficients remain lower the unity it is always possible to find a strategy for external gas puffing leading to a stationary state, with densities below the limit and efficient NBI absorption (>50%). The radioactive collapse can appear either at high densities (central value higher than 1.4x10''20 m''3), excessive influx of impurities (i. e. with sputtering rates higher than twice the expected values) o for insufficient injected beam power (less than 45 kW). The present study analyses only the 100{sub 4}4{sub 6}4 configuration of TJ-II, but future works will start a systematic scan of configuration using this same model. (Author) 12 Refs.

  6. Off-axis Neutral Beam Injection as a Tool for Expanding the Operating Space of DIII-D High fNI Discharges

    Science.gov (United States)

    Ferron, J. R.; Luce, T. C.; Politzer, P. A.; Deboo, J. C.; La Haye, R. J.; Holcomb, C. T.; Lanctot, M. J.; Turco, F.; Park, J. M.; in, Y.; Okabayashi, M.

    2011-10-01

    The newly installed capability for 5 MW off-axis neutral beam injection is being utilized to broaden the pressure and current density profiles and raise the minimum q value in DIII-D discharges with noninductive current fraction fNI near 1. Broader pressure is expected to allow stable access to increased βN and increase the bootstrap current density JBS off-axis. Reducing the on-axis current drive allows access to higher qmin, increasing the on-axis JBS and improving tearing mode stability. This is a path toward DIII-D (and a steady-state powerplant) fNI = 1 discharges at q95 = 5 , which require βN >= 4 . Initial experiments have demonstrated qmin maintained above 2 with broader pressure profiles than previously observed. Analysis of the noninductive current profiles and high βN stability of discharges with off-axis beam injection will be presented. Work supported in part by US DOE under DE-FC02-04ER54698, DE-AC52-07NA27344, DE-AC05-06OR23100, DE-AC05-00OR22725, DE-FG02-08ER85195, DE-AC02-09CH11466.

  7. The RHIC Injection System

    International Nuclear Information System (INIS)

    The RHIC injection system has to transport beam from the AGS-to-RHIC transfer line onto the closed orbits of the RHIC Blue and Yellow rings. This task can be divided into three problems. First, the beam has to be injected into either ring. Second, once injected the beam needs to be transported around the ring for one turn. Third, the orbit must be closed and coherent beam oscillations around the closed orbit should be minimized. They describe their solutions for these problems and report on system tests conducted during the RHIC Sextant test performed in 1997. The system will be fully commissioned in 1999

  8. Electrical spin injection into InGaAs/GaAs quantum wells: A comparison between MgO tunnel barriers grown by sputtering and molecular beam epitaxy methods

    International Nuclear Information System (INIS)

    An efficient electrical spin injection into an InGaAs/GaAs quantum well light emitting diode is demonstrated thanks to a CoFeB/MgO spin injector. The textured MgO tunnel barrier is fabricated by two different techniques: sputtering and molecular beam epitaxy. The maximal spin injection efficiency is comparable for both methods. Additionally, the effect of annealing is also investigated for the two types of samples. Both samples show the same trend: an increase of the electroluminescence circular polarization (Pc) with the increase of annealing temperature, followed by a saturation of Pc beyond 350 °C annealing. Since the increase of Pc starts well below the crystallization temperature of the full CoFeB bulk layer, this trend could be mainly due to an improvement of chemical structure at the top CoFeB/MgO interface. This study reveals that the control of CoFeB/MgO interface is essential for an optimal spin injection into semiconductor.

  9. Feasibility study of an optical resonator for applications in neutral-beam injection systems for the next generation of nuclear fusion reactors

    International Nuclear Information System (INIS)

    This work is part of a larger project called SIPHORE (Single gap Photo-neutralizer energy Recovery injector), which aims to enhance the overall efficiency of one of the mechanisms through which the plasma is heated, in a nuclear fusion reactor, i.e. the Neutral Beam Injection (NBI) system. An important component of a NBI system is the neutralizer of high energetic ion beams. SIPHORE proposes to substitute the gas cell neutralizer, used in the current NBI systems, with a photo-neutralizer exploiting the photo-detachment process within Fabry Perot cavities. This mechanism should allow a relevant NBI global efficiency of η≥ 60%, significantly higher than the one currently possible (η≤25% for ITER). The present work concerns the feasibility study of an optical cavity with suitable properties for applications in NBI systems. Within this context, the issue of the determination of an appropriated optical cavity design has been firstly considered and the theoretical and experimental analysis of a particular optical resonator has been carried on. The problems associated with the high levels of intracavity optical power (∼3 MW) required for an adequate photo-neutralization rate have then been faced. In this respect, we addressed both the problem of the thermal effects on the cavity mirrors due to their absorption of intra-cavity optical power (∼1 W) and the one associated to the necessity of a high powerful input laser beam (∼1 kW) to feed the optical resonator. (author)

  10. Modulation Of Low Energy Beam To Generate Predefined Bunch Trains For The NSLS-II Top-Off Injection

    International Nuclear Information System (INIS)

    The NSLS II linac will produce a bunch train, 80-150 bunches long with 2 ns bunch spacing. Having the ability to tailor the bunch train can lead to the smaller bunch to bunch charge variation in the storage ring. A stripline is planned to integrate into the linac baseline to achieve this tailoring. The stripline must have a fast field rise and fall time to tailor each bunch. The beam dynamics is minimally affected by including the extra space for the stripline. This paper discusses the linac beam dynamics with stripline, and the optimal design of the stripline. A stripline is to be integrated in the linac to match the storage ring uniform bunch charge requirement, which simplifies the gun pulser electronics and looses the edge uniform requirement. It is located at low energy to lower the stripline power supply requirement and limit the dumped electron radiation. By turning off the stripline, the beam dynamics through linac is comparable with the baseline design. More advanced ideas can be explored. If a DC corrector along with the stripline is used, the core bunch trains gets kick from the stripline while the head and the tail of bunch train just gets a DC kick. The stripline power supply waveform is a single flat top waveform with fast rise and drop and the pulse length is ∼200 ns long or 100 bunches, which may be easier from the power supply view point. We are also considering the bunch by bunch charge manipulation to match the storage ring uniform bunch charge distribution requirement. By modulating the flat top waveform at 250 MHz with adjustable amplitude, each the bunch center is either at 45 degree or 135 degree. Only the head or tail of the bunch is trimmed out. Although each bunch center deviation from idea center is very different at low energy, it is gradually minimized with beam energy increase.

  11. Transition of toroidal Alfven eigenmode to global Alfven eigenmode in CHS heliotron/torsatron plasmas heated by neutral beam injection

    International Nuclear Information System (INIS)

    A transition of a core localized type toroidal Alfven eigenmode with n 1 toroidal mode number to two n = 1 global Alfven eignemodes was observed in NBI-heated plasmas in the Compact Helical System (CHS) heliotron/torsatron. This transition phenomenon is interpreted based on the temporal evolution of the rotational transform near the plasma center caused by the increased in the beam-driven current. (author)

  12. Study of non-inductive current drive using high energy neutral beam injection on JT-60U

    International Nuclear Information System (INIS)

    The negative ion based neutral beam (N-NB) current drive was experimentally studied. The N-NB driven current density was determined over a wide range of electron temperatures by using the motional Stark effect spectroscopy. Theoretical prediction of the NB current drive increasing with beam energy and electron temperature was validated. A record value of NB current drive efficiency 1.55 x 1019 Am-2W-1 was achieved simultaneously with high confinement and high beta at at a plasma current of 1.5 MA under a fully non-inductively current driven condition. The experimental validation of NB current drive theory for MHD quiescent plasmas gives greater confidence in predicting the NB current drive in future reactors. However, it was also found that MHD instabilities caused a degradation of NB current drive. A beam-driven instability expelled N-NB fast ions carrying non-inductive current from the central region. The lost N-NB driven current was estimated to be 7% of the total N-NB driven current. For the neoclassical tearing mode (NTM), comparisons of the measured neutron yield and fast ion pressure profile with transport code calculations revealed that the loss of fast ions increases with the NTM activity and that fast ions at higher energies suffer larger transport than at lower energies. (author)

  13. Neutral-beam-injection fueling for a small, D-3He burning, field-reversed-configuration reactor

    Science.gov (United States)

    Buttolph, Michael; Stotler, Daren; Cohen, Samuel

    2013-10-01

    Rocket propulsion powered by the D-3He fusion reaction in a Field Reversed Configuration (FRC) has been proposed for a variety of solar-system missions. Two key unique features of this concept are a relatively small, 25-cm-radius, plasma core and a relatively thick (10 cm), dense (1e14 cm3), and cool (100 eV electron temperature) scrape-off layer (SOL). The SOL contains the heated propellant - likely hydrogen, deuterium or helium - and also fusion reaction products at a lower density (ca. 1e12 cm-3). A critical design question is the refueling of the fusion reactants. A moderate energy neutral-beam method is considered. It must be able to penetrate the SOL without significant losses but must be stopped in the core. DEGAS 2, a Monte-Carlo code designed to model neutral transport, was implemented to simulate beam-plasma interactions including ionization and charge exchange of the neutral beam's helium-3 and deuterium atoms by impact in the SOL and core plasma with thermal plasma constituents and fusion reaction products. Operational methods to alleviate the effects deleterious reactions such as deuterium charge-exchange in the SOL are described.

  14. Operation of 15 MW negative-ion-based neutral beam injection system for the large helical device

    Energy Technology Data Exchange (ETDEWEB)

    Oka, Y.; Takeiri, Y.; Tsumori, K.; Kaneko, O.; Osakabe, M.; Asano, E.; Kawamoto, T.; Akiyama, R. [National Inst. for Fusion Science, Toki, Gifu (Japan)

    1998-07-01

    National Institute for Fusion Science (NIFS) has succeeded in generating a newly first plasma of the Large Helical Device (LHD) in March of 1998. To achieve LHD-NBI requirement, two 7.5 MW NBI systems have been established in the LHD hall and it's been in a final stage to start a normal heating experiment in this September. The system is featured by negative-ion-based system with high current (40 A) H- ion sources at a medium energy (180 keV) and by a particular design/fabrication aiming at long-pulse/quasi state injection. Operation/test results are presented. (author)

  15. Resistive wall mode stabilization by slow plasma rotation in DIII-D tokamak discharges with balanced neutral beam injection

    International Nuclear Information System (INIS)

    Recent experiments in the DIII-D tokamak [J. L. Luxon, Nucl. Fusion 42, 614 (2002)] show that the resistive wall mode (RWM) can be stabilized by smaller values of plasma rotation than previously reported. Stable discharges have been observed with beta up to 1.4 times the no-wall kink stability limit and ion rotation velocity (measured from CVI emission) less than 0.3% of the Alfven speed at all integer rational surfaces, in contrast with previous DIII-D experiments that indicated critical values of 0.7%-2.5% of the local Alfven speed. Preliminary stability calculations for these discharges, using ideal magnetohydrodynamics with a drift-kinetic dissipation model, are consistent with the new experimental results. A key feature of these experiments is that slow plasma rotation was achieved by reducing the neutral beam torque. Earlier experiments with strong neutral beam torque used ''magnetic braking'' by applied magnetic perturbations to slow the rotation, and resonant effects of these perturbations may have led to a larger effective rotation threshold. In addition, the edge rotation profile may have a critical role in determining the RWM stability of these low-torque plasmas

  16. Beam Dynamics Studies of ECR Injections for the Coupled Cyclotron Facility at NSCL%NSCL从ECR离子源向CCF注入的离子束流动力学研究

    Institute of Scientific and Technical Information of China (English)

    X.Wu; Q.Zhao; D.Cole; M.Doleans; G.Machicoane; F.Marti; P.Miller; J.Stetson; M.Steiner; P.Zavodszky

    2007-01-01

    The Coupled Cyclotron Facility(CCF)has been operating at the NSCL since 2001,providing up to 160MeV/u heavy ion beams for nuclear physics experiments.Recent steps,particularly the improvement of the ECR-to-K500 injection line,were taken to improve the CCF performance.For that purpose an off-line ECR source.ARTEMIS-B,was built and used to investigate the impact on beam brightness under various source operating conditions,different initial focusing systems and current analysis dipole.Beam dynamics simulations including space-charge and 3D electrostatic field effects were performed and beam diagnostics including emittance scanner were used,leading to a better understanding of the CCF beam injection process New initial electrostatic focusing elements such as a large-bore quadrupole triplet and a quadrupole doubledoublet with compensating octupole were tested,and a new beam tuning procedure was established to improve the beam brightness for the CCF.Following these efforts,a significant increase of primary beam power out of the CCF has been achieved.

  17. Modular ultrahigh vacuum-compatible gas-injection system with an adjustable gas flow for focused particle beam-induced deposition

    International Nuclear Information System (INIS)

    A gas-injection system (GIS) heats up a powdery substance and transports the resulting gas through a capillary into a vacuum chamber. Such a system can be used to guide a (metal)organic precursor gas very close to the focal area of an electron or ion beam, where a permanent deposit is created and adheres to the substrate. This process is known as focused particle beam-induced deposition. The authors present design principles and give construction details of a GIS suitable for ultrahigh vacuum usage. The GIS is composed of several self-contained components which can be customized rather independently. It allows for a continuously adjustable gas-flow rate. The GIS was attached to a standard scanning electron microscope (JEOL 6100) and tested with the tungsten precursor W(CO)6. The analysis of the deposits by means of atomic force microscopy and energy dispersive x-ray spectroscopy provides clear evidence that excellent gas-flow-rate stability and ensuing growth rate and metal-content reproducibility are experienced.

  18. On the meniscus formation and the negative hydrogen ion extraction from ITER neutral beam injection relevant ion source

    Science.gov (United States)

    Mochalskyy, S.; Wünderlich, D.; Ruf, B.; Fantz, U.; Franzen, P.; Minea, T.

    2014-10-01

    The development of a large area (Asource,ITER = 0.9 × 2 m2) hydrogen negative ion (NI) source constitutes a crucial step in construction of the neutral beam injectors of the international fusion reactor ITER. To understand the plasma behaviour in the boundary layer close to the extraction system the 3D PIC MCC code ONIX is exploited. Direct cross checked analysis of the simulation and experimental results from the ITER-relevant BATMAN source testbed with a smaller area (Asource,BATMAN ≈ 0.32 × 0.59 m2) has been conducted for a low perveance beam, but for a full set of plasma parameters available. ONIX has been partially benchmarked by comparison to the results obtained using the commercial particle tracing code for positive ion extraction KOBRA3D. Very good agreement has been found in terms of meniscus position and its shape for simulations of different plasma densities. The influence of the initial plasma composition on the final meniscus structure was then investigated for NIs. As expected from the Child-Langmuir law, the results show that not only does the extraction potential play a crucial role on the meniscus formation, but also the initial plasma density and its electronegativity. For the given parameters, the calculated meniscus locates a few mm downstream of the plasma grid aperture provoking a direct NI extraction. Most of the surface produced NIs do not reach the plasma bulk, but move directly towards the extraction grid guided by the extraction field. Even for artificially increased electronegativity of the bulk plasma the extracted NI current from this region is low. This observation indicates a high relevance of the direct NI extraction. These calculations show that the extracted NI current from the bulk region is low even if a complete ion-ion plasma is assumed, meaning that direct extraction from surface produced ions should be present in order to obtain sufficiently high extracted NI current density. The calculated extracted currents, both ions

  19. Electron beam injected into ground generates subsoil x-rays that may deactivate concealed electronics used to trigger explosive devices

    Science.gov (United States)

    Retsky, Michael

    2008-04-01

    Explosively formed projectiles (EFP) are a major problem in terrorism and asymmetrical warfare. EFPs are often triggered by ordinary infrared motion detectors. A potential weak link is that such electronics are not hardened to ionizing radiation and can latch-up or enter other inoperative states after exposure to a single short event of ionizing radiation. While these can often be repaired with a power restart, they also can produce shorts and permanent damage. A problem of course is that we do not want to add radiation exposure to the long list of war related hazards. Biological systems are highly sensitive to integrated dosage but show no particular sensitivity to short pulses. There may be a way to generate short pulsed subsoil radiation to deactivate concealed electronics without introducing radiation hazards to military personnel and civilian bystanders. Electron beams of 30 MeV that can be produced by portable linear accelerators (linacs) propagate >20 m in air and 10-12 cm in soil. X-radiation is produced by bremsstrahlung and occurs subsoil beneath the point of impact and is mostly forward directed. Linacs 1.5 m long can produce 66 MWatt pulses of subsoil x-radiation 1 microsecond or less in duration. Untested as yet, such a device could be mounted on a robotic vehicle that precedes a military convoy and deactivates any concealed electronics within 10-20 meters on either side of the road.

  20. The LHC Injection Tests

    CERN Document Server

    Aberle, O; Aiba, M; Albert, M; Alemany-Fernandez, R; Arduini, Gianluigi; Assmann, Ralph Wolfgang; Bailey, R; Billen, R; Bottura, L; Brüning, Oliver Sim; Butterworth, A; Calaga, R; Carlier, E; Collier, P; Dehning, B; Deniau, L; Fartoukh, S; Follin, F; Forkel-Wirth, D; Fuchsberger, K; Giachino, R; Giovannozzi, M; Goddard, B; Gras, J J; Hatziangeli, E; Hagen, P; Jacquet, D; Jensen, L; Jones, R; Kain, V; Kozsar, I; Kramer, T; Kruk, G; Lamont, M; Lewis, J; Losito, R; MacPherson, A; Masi, A; Meddahi, M; Mertens, V; Misiowiec, M; Page, S; Ponce, L; Puccio, B; Redaelli, S; Roderick, C; Roesler, S; Roncarolo, F; Sapinski, M; Schmidt, F; Schmidt, R; Sliwinski, W; Steinhagen, R; Strzelczyk, M; Sun, Y; Todd, B; Todesco, E; Tomas Garcia, R; Uythoven, J; Venturini-Delsolaro, W; Vincke, H; Vincke, H; Veyrunes, E; Wenninger, J; Wolf, R; Zamantzas, C; Zimmermann, F

    2008-01-01

    A series of LHC injection tests was performed in August and September 2008. The first saw beam injected into sector 23; the second into sectors 78 and 23; the third into sectors 78-67 and sectors 23-34-45. The fourth, into sectors 23-34-45, was performed the evening before the extended injection test on the 10th September which saw both beams brought around the full circumference of the LHC. The tests enabled the testing and debugging of a number of critical control and hardware systems; testing and validation of instrumentation with beam for the first time; deployment, and validation of a number of measurement procedures. Beam based measurements revealed a number of machine configuration issues that were rapidly resolved. The tests were undoubtedly an essential precursor to the successful start of LHC beam commissioning. This paper provides an outline of preparation for the tests, the machine configuration and summarizes the measurements made and individual system performance.

  1. Combination of External Beam Radiotherapy (EBRT) With Intratumoral Injection of Dendritic Cells as Neo-Adjuvant Treatment of High-Risk Soft Tissue Sarcoma Patients

    Energy Technology Data Exchange (ETDEWEB)

    Finkelstein, Steven E., E-mail: steven.finkelstein@moffitt.org [H. Lee Moffitt Cancer Center, Tampa, FL (United States); Iclozan, Cristina; Bui, Marilyn M.; Cotter, Matthew J.; Ramakrishnan, Rupal; Ahmed, Jamil; Noyes, David R.; Cheong, David; Gonzalez, Ricardo J.; Heysek, Randy V.; Berman, Claudia; Lenox, Brianna C.; Janssen, William; Zager, Jonathan S.; Sondak, Vernon K.; Letson, G. Douglas; Antonia, Scott J. [H. Lee Moffitt Cancer Center, Tampa, FL (United States); Gabrilovich, Dmitry I., E-mail: dmitry.gabrilovich@moffitt.org [H. Lee Moffitt Cancer Center, Tampa, FL (United States)

    2012-02-01

    Purpose: The goal of this study was to determine the effect of combination of intratumoral administration of dendritic cells (DC) and fractionated external beam radiation (EBRT) on tumor-specific immune responses in patients with soft-tissue sarcoma (STS). Methods and Material: Seventeen patients with large (>5 cm) high-grade STS were enrolled in the study. They were treated in the neoadjuvant setting with 5,040 cGy of EBRT, split into 28 fractions and delivered 5 days per week, combined with intratumoral injection of 10{sup 7} DCs followed by complete resection. DCs were injected on the second, third, and fourth Friday of the treatment cycle. Clinical evaluation and immunological assessments were performed. Results: The treatment was well tolerated. No patient had tumor-specific immune responses before combined EBRT/DC therapy; 9 patients (52.9%) developed tumor-specific immune responses, which lasted from 11 to 42 weeks. Twelve of 17 patients (70.6%) were progression free after 1 year. Treatment caused a dramatic accumulation of T cells in the tumor. The presence of CD4{sup +} T cells in the tumor positively correlated with tumor-specific immune responses that developed following combined therapy. Accumulation of myeloid-derived suppressor cells but not regulatory T cells negatively correlated with the development of tumor-specific immune responses. Experiments with {sup 111}In labeled DCs demonstrated that these antigen presenting cells need at least 48 h to start migrating from tumor site. Conclusions: Combination of intratumoral DC administration with EBRT was safe and resulted in induction of antitumor immune responses. This suggests that this therapy is promising and needs further testing in clinical trials design to assess clinical efficacy.

  2. Combination of External Beam Radiotherapy (EBRT) With Intratumoral Injection of Dendritic Cells as Neo-Adjuvant Treatment of High-Risk Soft Tissue Sarcoma Patients

    International Nuclear Information System (INIS)

    Purpose: The goal of this study was to determine the effect of combination of intratumoral administration of dendritic cells (DC) and fractionated external beam radiation (EBRT) on tumor-specific immune responses in patients with soft-tissue sarcoma (STS). Methods and Material: Seventeen patients with large (>5 cm) high-grade STS were enrolled in the study. They were treated in the neoadjuvant setting with 5,040 cGy of EBRT, split into 28 fractions and delivered 5 days per week, combined with intratumoral injection of 107 DCs followed by complete resection. DCs were injected on the second, third, and fourth Friday of the treatment cycle. Clinical evaluation and immunological assessments were performed. Results: The treatment was well tolerated. No patient had tumor-specific immune responses before combined EBRT/DC therapy; 9 patients (52.9%) developed tumor-specific immune responses, which lasted from 11 to 42 weeks. Twelve of 17 patients (70.6%) were progression free after 1 year. Treatment caused a dramatic accumulation of T cells in the tumor. The presence of CD4+ T cells in the tumor positively correlated with tumor-specific immune responses that developed following combined therapy. Accumulation of myeloid-derived suppressor cells but not regulatory T cells negatively correlated with the development of tumor-specific immune responses. Experiments with 111In labeled DCs demonstrated that these antigen presenting cells need at least 48 h to start migrating from tumor site. Conclusions: Combination of intratumoral DC administration with EBRT was safe and resulted in induction of antitumor immune responses. This suggests that this therapy is promising and needs further testing in clinical trials design to assess clinical efficacy.

  3. Fabrication and installment of the hard-wired I and C works for the neutral beam injection test stand of the K-STAR project

    International Nuclear Information System (INIS)

    Instrumentation and Control(I and C) of the neutral beam injection test stand (NBI-TS) for the K-STAR national fusion research project has been underway since the start of the project to answer the diverse requests arising from the various facets of the development and construction phases of the project. In a parallel effort with the software oriented I and C development, there has been existing an enormous amount of hard-wiring I and C works for the NBI facility to be developed and fabricated in schedule. Circuits and hardwired functions have been designed, tested, fabricated, and finally installed to the relevant parts of the system. Examples of those hard-wired I and C works are related to the vacuum system, gas feeding system, arc detector circuit, ion source monitoring, bending magnet and calorimeter. Another one to be mentioned is the interlock circuitry. One of the interlock circuits are related to the coolant flow failure. The other is the interlock circuit related to the vacuum failure. All of the above mentioned circuitry now constitutes integral parts for the proper operation of the NBI system; details of those hard-wired I and C work are described in this report

  4. Echo III: The study of electric and magnetic fields with conjugate echoes from artificial electron beams injected into the auroral zone ionosphere

    International Nuclear Information System (INIS)

    The third in a series of rocket flights carrying large electron guns for electron beam-plasma analysis and magnetosphere probing has been carried out from the Poker Flat rocket range near Fairbanks, Alaska at L=6. Echoes from the injected electrons mirroring at the southern hemisphere conjugate point were observed on the rocket by particle detectors and in the nearby ionosphere by photometers on board the rocket. The bounce time and drift velocities of the echoes were measured using the known trajectory and aspect of the rocket. Ionospheric electric fields near the rocket were inferred from drift motion of the ambient ion population measured by two techniques, electrostatic analyzers on board the rocket and incoherent backscatter radar from the ground. Using model magnetic fields, gradient and curvature drift and bound times have been computed under the conditions appropriate for this experiment. Assuming that field lines are equipotentials, the addition of the observed ionospheric electric field drift to the model-independent gradient and curvature drifts predicts a net echo drift velocity that is in agreement with the observations, provided the Mead-Fairfield 1972--73 model is used. The observed bounce time constitutes an independent model check and is in better agreement with the Olson-Pfitzer model. Echo spatial and temporal fluctuations reflected the turbulence associated with the diffuse aurora into which the rocket was launched

  5. Unenhanced Cone Beam Computed Tomography and Fusion Imaging in Direct Percutaneous Sac Injection for Treatment of Type II Endoleak: Technical Note

    Energy Technology Data Exchange (ETDEWEB)

    Carrafiello, Gianpaolo, E-mail: gcarraf@gmail.com; Ierardi, Anna Maria [Insubria University, Interventional Radiology, Department of Radiology (Italy); Radaelli, Alessandro [Philips Healthcare (Netherlands); Marchi, Giuseppe De; Floridi, Chiara [Insubria University, Interventional Radiology, Department of Radiology (Italy); Piffaretti, Gabriele [University of Insubria, Vascular Surgery Department (Italy); Federico, Fontana [Insubria University, Interventional Radiology, Department of Radiology (Italy)

    2016-03-15

    AimTo evaluate safety, feasibility, technical success, and clinical success of direct percutaneous sac injection (DPSI) for the treatment of type II endoleaks (T2EL) using anatomical landmarks on cone beam computed tomography (CBCT) and fusion imaging (FI).Materials and MethodsEight patients with T2EL were treated with DPSI using CBCT as imaging guidance. Anatomical landmarks on unenhanced CBCT were used for referencing T2EL location in the first five patients, while FI between unenhanced CBCT and pre-procedural computed tomography angiography (CTA) was used in the remaining three patients. Embolization was performed with thrombin, glue, and ethylene–vinyl alcohol copolymer. Technical and clinical success, iodinated contrast utilization, procedural time, fluoroscopy time, and mean radiation dose were registered.ResultsDPSI was technically successful in all patients: the needle was correctly positioned at the first attempt in six patients, while in two of the first five patients the needle was repositioned once. Neither minor nor major complications were registered. Average procedural time was 45 min and the average administered iodinated contrast was 13 ml. Mean radiation dose of the procedure was 60.43 Gy cm{sup 2} and mean fluoroscopy time was 18 min. Clinical success was achieved in all patients (mean follow-up of 36 months): no sign of T2EL was reported in seven patients until last CT follow-up, while it persisted in one patient with stability of sac diameter.ConclusionsDPSI using unenhanced CBCT and FI is feasible and provides the interventional radiologist with an accurate and safe alternative to endovascular treatment with limited iodinated contrast utilization.

  6. Unenhanced Cone Beam Computed Tomography and Fusion Imaging in Direct Percutaneous Sac Injection for Treatment of Type II Endoleak: Technical Note

    International Nuclear Information System (INIS)

    AimTo evaluate safety, feasibility, technical success, and clinical success of direct percutaneous sac injection (DPSI) for the treatment of type II endoleaks (T2EL) using anatomical landmarks on cone beam computed tomography (CBCT) and fusion imaging (FI).Materials and MethodsEight patients with T2EL were treated with DPSI using CBCT as imaging guidance. Anatomical landmarks on unenhanced CBCT were used for referencing T2EL location in the first five patients, while FI between unenhanced CBCT and pre-procedural computed tomography angiography (CTA) was used in the remaining three patients. Embolization was performed with thrombin, glue, and ethylene–vinyl alcohol copolymer. Technical and clinical success, iodinated contrast utilization, procedural time, fluoroscopy time, and mean radiation dose were registered.ResultsDPSI was technically successful in all patients: the needle was correctly positioned at the first attempt in six patients, while in two of the first five patients the needle was repositioned once. Neither minor nor major complications were registered. Average procedural time was 45 min and the average administered iodinated contrast was 13 ml. Mean radiation dose of the procedure was 60.43 Gy cm2 and mean fluoroscopy time was 18 min. Clinical success was achieved in all patients (mean follow-up of 36 months): no sign of T2EL was reported in seven patients until last CT follow-up, while it persisted in one patient with stability of sac diameter.ConclusionsDPSI using unenhanced CBCT and FI is feasible and provides the interventional radiologist with an accurate and safe alternative to endovascular treatment with limited iodinated contrast utilization

  7. FINAL TECHNICAL REPORT FOR DE-FG02-05ER64097 Systems and Methods for Injecting Helium Beams into a Synchrotron Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Bush, David A

    2008-09-30

    A research grant was approved to fund development of requirements and concepts for extracting a helium-ion beam at the LLUMC proton accelerator facility, thus enabling the facility to better simulate the deep space environment via beams sufficient to study biological effects of accelerated helium ions in living tissues. A biologically meaningful helium-ion beam will be accomplished by implementing enhancements to increase the accelerator's maximum proton beam energy output from 250MeV to 300MeV. Additional benefits anticipated from the increased energy include the capability to compare possible benefits from helium-beam radiation treatment with proton-beam treatment, and to provide a platform for developing a future proton computed tomography imaging system.

  8. Injection and Dump Systems

    CERN Document Server

    Bracco, C; Barnes, M J; Carlier, E; Drosdal, L N; Goddard, B; Kain, V; Meddahi, M; Mertens, V; Uythoven, J

    2012-01-01

    Performance and failures of the LHC injection and ex- traction systems are presented. In particular, a comparison with the 2010 run, lessons learnt during operation with high intensity beams and foreseen upgrades are described. UFOs, vacuum and impedance problems related to the injection and extraction equipment are analysed together with possible improvements and solutions. New implemented features, diagnostics, critical issues of XPOC and IQC applications are addressed.

  9. Oxacillin Injection

    Science.gov (United States)

    Oxacillin injection is used to treat infections caused by certain bacteria. Oxacillin injection is in a class of medications called ... It works by killing bacteria.Antibiotics such as oxacillin injection will not work for colds, flu, or ...

  10. PS injection area

    CERN Multimedia

    1974-01-01

    Looking against the direction of protons in the main ring (left): the beam coming from the linac 1 either goes to the booster (on the right) or is deflected towards the PS to be directly injected into section 26 (facing the camera). Also shown the start of the TT2 line, ejected from straight section 16 to go towards the ISR passing over the beam line from the linac. (see Photo Archive 7409009)

  11. Controlling Beamloss at Injection into the LHC

    CERN Document Server

    Goddard, B; Appleby, R B; Bartmann, W; Baudrenghien, P; Boccone, V; Bracco, C; Brugger, M; Cornelis, K; Dehning, B; del Busto, E; Di Mauro, A; Drosdal, L; Höfle, W; Holzer, E B; Jacobsson, R; Kain, V; Meddahi, M; Mertens, V; Nordt, A; Uythoven, J; Valuch, D; Weisz, S

    2011-01-01

    Losses at injection into the superconducting LHC can adversely affect the machine performance in several important ways. The high injected beam intensity and energy mean that precautions must be taken against damage and quenches, including collimators placed close to the beam in the injection regions. Clean injection is essential, to avoid spurious signals on the sensitive beam loss monitoring system which will trigger beam dumps. In addition, the use of the two injection insertions to house downstream high energy physics experiments brings constraints on permitted beam loss levels. In this paper the sources of injection beam loss are discussed together with the contributing factors and various issues experienced in the first full year of LHC operation. Simulations are compared with measurement, and the implemented and planned mitigation measures and diagnostic improvements are described. An outlook for future LHC operation is given.

  12. MKI UFOs at Injection

    CERN Document Server

    Baer, T; Bartmann, W; Bracco, C; Carlier, E; Chanavat, C; Drosdal, L; Garrel, N; Goddard, B; Kain, V; Mertens, V; Uythoven, J; Wenninger, J; Zerlauth, M

    2011-01-01

    During the MD, the production mechanism of UFOs at the injection kicker magnets (MKIs) was studied. This was done by pulsing the MKIs on a gap in the circulating beam, which led to an increased number of UFOs. In total 43 UFO type beam loss patterns at the MKIs were observed during the MD. The MD showed that pulsing the MKIs directly induces UFO type beam loss patterns. From the temporal characteristics of the loss profile, estimations about the dynamics of the UFOs are made.

  13. Self-modulation of a long externally injected relativistic charged-particle beam in a laser wake field acceleration scheme. A preliminary quantum-like investigation

    International Nuclear Information System (INIS)

    Recent investigations indicate that sufficiently long beams of charged particles, travelling in a plasma, experience the phenomenon of self-modulation. The self-modulation is driven by the plasma wake field excitation due to the beam itself, and it may become unstable under certain conditions. A preliminary theoretical investigation of the self-modulation of a relativistic charged-particle beam in overdense plasma in the presence of a preformed plasma wave is carried out, within the quantum-like description of charged particle beams provided by the Thermal Wave Model. A simple physical model for the self-modulation is put forward, described by a nonlinear Schrödinger equation coupled with the Poisson-like equation for the plasma wake potential (so-called Fedele–Shukla equations). The physical mechanism is based on the interplay of three concomitant effects, the radial thermal dispersion (associated with the emittance ε), the radial ponderomotive effects of a preexisting plasma wave (which provides the guidance for the beam), and the self-interaction of the plasma wake field generated by the beam itself

  14. Injection method using the third order resonance at TARN II

    International Nuclear Information System (INIS)

    The beam was successfully stored in the TARN II ring by an injection method using the third order resonance. Beam intensity obtained by the resonance injection is comparable with that by the multiturn injection. A new stacking method utilizing the resonance injection and the electron cooling is introduced. (author)

  15. Multi-bunch injection for SSRF storage ring

    CERN Document Server

    Jiang, Bocheng; Wang, Baoliang; Zhang, Manzhou; Yin, Chongxian; Yan, Yingbing; Tian, Shunqiang; Wang, Kun

    2015-01-01

    The multi-bunch injection has been adopt at SSRF which greatly increases the injection rate and reduces injection time compared to the single bunch injection. The multi-bunch injection will massively reduce the beam failure time during users operation and prolong pulsed injection hardware lifetime. In this paper, the scheme to produce multi bunches for the RF electron gun is described. The refilling result and the beam orbit stability for top up operation is discussed.

  16. A new deflection technique applied to an existing scheme of electrostatic accelerator for high energy neutral beam injection in fusion reactor devices

    Science.gov (United States)

    Pilan, N.; Antoni, V.; De Lorenzi, A.; Chitarin, G.; Veltri, P.; Sartori, E.

    2016-02-01

    A scheme of a neutral beam injector (NBI), based on electrostatic acceleration and magneto-static deflection of negative ions, is proposed and analyzed in terms of feasibility and performance. The scheme is based on the deflection of a high energy (2 MeV) and high current (some tens of amperes) negative ion beam by a large magnetic deflector placed between the Beam Source (BS) and the neutralizer. This scheme has the potential of solving two key issues, which at present limit the applicability of a NBI to a fusion reactor: the maximum achievable acceleration voltage and the direct exposure of the BS to the flux of neutrons and radiation coming from the fusion reactor. In order to solve these two issues, a magnetic deflector is proposed to screen the BS from direct exposure to radiation and neutrons so that the voltage insulation between the electrostatic accelerator and the grounded vessel can be enhanced by using compressed SF6 instead of vacuum so that the negative ions can be accelerated at energies higher than 1 MeV. By solving the beam transport with different magnetic deflector properties, an optimum scheme has been found which is shown to be effective to guarantee both the steering effect and the beam aiming.

  17. A new deflection technique applied to an existing scheme of electrostatic accelerator for high energy neutral beam injection in fusion reactor devices

    Energy Technology Data Exchange (ETDEWEB)

    Pilan, N., E-mail: nicola.pilan@igi.cnr.it; Antoni, V.; De Lorenzi, A.; Chitarin, G.; Veltri, P.; Sartori, E. [Consorzio RFX—Associazione EURATOM-ENEA per la Fusione, Corso Stati Uniti 4, 35127 Padova (Italy)

    2016-02-15

    A scheme of a neutral beam injector (NBI), based on electrostatic acceleration and magneto-static deflection of negative ions, is proposed and analyzed in terms of feasibility and performance. The scheme is based on the deflection of a high energy (2 MeV) and high current (some tens of amperes) negative ion beam by a large magnetic deflector placed between the Beam Source (BS) and the neutralizer. This scheme has the potential of solving two key issues, which at present limit the applicability of a NBI to a fusion reactor: the maximum achievable acceleration voltage and the direct exposure of the BS to the flux of neutrons and radiation coming from the fusion reactor. In order to solve these two issues, a magnetic deflector is proposed to screen the BS from direct exposure to radiation and neutrons so that the voltage insulation between the electrostatic accelerator and the grounded vessel can be enhanced by using compressed SF{sub 6} instead of vacuum so that the negative ions can be accelerated at energies higher than 1 MeV. By solving the beam transport with different magnetic deflector properties, an optimum scheme has been found which is shown to be effective to guarantee both the steering effect and the beam aiming.

  18. A new deflection technique applied to an existing scheme of electrostatic accelerator for high energy neutral beam injection in fusion reactor devices

    International Nuclear Information System (INIS)

    A scheme of a neutral beam injector (NBI), based on electrostatic acceleration and magneto-static deflection of negative ions, is proposed and analyzed in terms of feasibility and performance. The scheme is based on the deflection of a high energy (2 MeV) and high current (some tens of amperes) negative ion beam by a large magnetic deflector placed between the Beam Source (BS) and the neutralizer. This scheme has the potential of solving two key issues, which at present limit the applicability of a NBI to a fusion reactor: the maximum achievable acceleration voltage and the direct exposure of the BS to the flux of neutrons and radiation coming from the fusion reactor. In order to solve these two issues, a magnetic deflector is proposed to screen the BS from direct exposure to radiation and neutrons so that the voltage insulation between the electrostatic accelerator and the grounded vessel can be enhanced by using compressed SF6 instead of vacuum so that the negative ions can be accelerated at energies higher than 1 MeV. By solving the beam transport with different magnetic deflector properties, an optimum scheme has been found which is shown to be effective to guarantee both the steering effect and the beam aiming

  19. Transverse emittance blow-up of the heavy ion beam injected into the SPS from the proposed MSI-V septum

    CERN Document Server

    Velotti, Francesco Maria; Uythoven, Jan; CERN. Geneva. ATS Department

    2014-01-01

    The initial specification for the MSI-V current ripples was 1000 ppm, but recent developments asked for a maximum ripple between 100 and 1000 ppm. The effect of such errors has to be properly evaluated, together with the other sources of injection errors (MSI, MKP).

  20. Teduglutide Injection

    Science.gov (United States)

    Teduglutide injection is used to treat short bowel syndrome in people who need additional nutrition or fluids from intravenous (IV) therapy. Teduglutide injection is in a class of medications called ...

  1. Levofloxacin Injection

    Science.gov (United States)

    Levofloxacin injection is used to treat infections such as pneumonia; chronic bronchitis; and sinus, urinary tract, kidney, prostate (a male reproductive gland), and skin infections. Levofloxacin injection is also used to prevent anthrax (a ...

  2. Estrogen Injection

    Science.gov (United States)

    The estradiol cypionate and estradiol valerate forms of estrogen injection are used to treat hot flushes (hot ... should consider a different treatment. These forms of estrogen injection are also sometimes used to treat the ...

  3. Ziprasidone Injection

    Science.gov (United States)

    ... of interest in life, and strong or inappropriate emotions). Ziprasidone is in a class of medications called ... alcoholic beverages while you are receiving ziprasidone injection. Alcohol can make the side effects from ziprasidone injection ...

  4. Leucovorin Injection

    Science.gov (United States)

    ... injection is used to prevent harmful effects of methotrexate (Rheumatrex, Trexall; cancer chemotherapy medication) when methotrexate is used to to treat certain types of cancer. Leucovorin injection is used to treat people who ...

  5. Paclitaxel Injection

    Science.gov (United States)

    Paclitaxel injection manufactured with human albumin is used to treat breast cancer that has not improved or ... has come back after treatment with other medications. Paclitaxel injection manufactured with polyoxyethylated castor oil is used ...

  6. Denosumab Injection

    Science.gov (United States)

    ... injection is in a class of medications called RANK ligand inhibitors. It works by decreasing bone breakdown ... months. When denosumab injection (Xgeva) is used to reduce fractures from cancer that has spread to the ...

  7. Sumatriptan Injection

    Science.gov (United States)

    ... the brain, and blocking the release of certain natural substances that cause pain, nausea, and other symptoms ... or upper arm. Do not inject sumatriptan through clothing. Never inject sumatriptan into a vein or muscle. ...

  8. Dexamethasone Injection

    Science.gov (United States)

    Dexamethasone injection is used to treat severe allergic reactions. It is used in the management of certain ... tissues,) gastrointestinal disease, and certain types of arthritis. Dexamethasone injection is also used for diagnostic testing. Dexamethasone ...

  9. Ferumoxytol Injection

    Science.gov (United States)

    Ferumoxytol injection is used to treat iron-deficiency anemia (a lower than normal number of red blood ... are pregnant, plan to become pregnant, or are breastfeeding. If you become pregnant while receiving ferumoxytol injection, ...

  10. Golimumab Injection

    Science.gov (United States)

    ... appears damaged, and do not use an auto-injection device if the security seal is broken. Look through the viewing window on the prefilled syringe or auto-injection device. The liquid inside should be clear and ...

  11. Cyclosporine Injection

    Science.gov (United States)

    ... injection is used with other medications to prevent transplant rejection (attack of the transplanted organ by the immune system of the person receiving the organ) in people who have received kidney, liver, and heart transplants. Cyclosporine injection should only ...

  12. Doxycycline Injection

    Science.gov (United States)

    Doxycycline injection is used to treat or prevent bacterial infections, including pneumonia and other respiratory tract infections. ... certain skin, genital, intestine, and urinary system infections. Doxycycline injection may be used to treat or prevent ...

  13. Subcutaneous Injections

    DEFF Research Database (Denmark)

    Thomsen, Maria

    at the injection site was influenced by the needle length and the injected volume. Several imaging analysis tools were optimized for the characterization, and these tools were implemented also on subcutaneous injections in rats, visualized by low dose μCT, and used for characterization of the morphology in mouse...

  14. Transient Enhancement ('Spike-on-Tail') Observed on Neutral-Beam-Injected Energetic Ion Spectra Using the E||B Neutral Particle Analyzer in the National Spherical Torus Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Medley, S. S. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Gorelenkov, N. N. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Bell, R. E. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Fredrickson, E. D. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Gerhardt, S. P. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); LeBlanc, B. P. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Podesta, M. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Roquemore, A. L. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

    2010-06-01

    An increase of up to four-fold in the E||B Neutral Particle Analyzer (NPA) charge exchange neutral flux localized at the Neutral Beam (NB) injection full energy is observed in the National Spherical Torus Experiment (NSTX). Termed the High-Energy Feature (HEF), it appears on the NB-injected energetic ion spectrum only in discharges where tearing or kink-type modes (f < 10 kHz) are absent, TAE activity (f ~ 10-150 kHz) is weak (δBrms < 75 mGauss) and CAE/GAE activity (f ~ 400 – 1200 kHz) is robust. The feature exhibits a growth time of ~ 20 - 80 ms and occasionally develops a slowing down distribution that continues to evolve over periods of 100's of milliseconds, a time scale long compared with the typical ~ 10's ms equilibration time of the NB injected particles. The HEF is observed only in H-mode (not L-mode) discharges with injected NB power of 4 MW or greater and in the field pitch range v||/v ~ 0.7 – 0.9; i.e. only for passing (never trapped) energetic ions. The HEF is suppressed by vessel conditioning using lithium deposition at rates ~ 100 mg/shot, a level sufficient to suppress ELM activity. Increases of ~ 10 - 30 % in the measured neutron yield and total stored energy are observed to coincide with the feature along with broadening of measured Te(r), Ti(r) and ne(r) profiles. However, TRANSP analysis shows that such increases are driven by plasma profile changes and not the HEF phenomenon itself. Though a definitive mechanism has yet to be developed, the HEF appears to be caused by a form of TAE/CAE wave-particle interaction that distorts of the NB fast ion distribution in phase space.

  15. Beam-Beam Effects

    OpenAIRE

    Herr, W; Pieloni, T.

    2016-01-01

    One of the most severe limitations in high-intensity particle colliders is the beam-beam interaction, i.e. the perturbation of the beams as they cross the opposing beams. This introduction to beam-beam effects concentrates on a description of the phenomena that are present in modern colliding beam facilities.

  16. Beam-Beam Effects

    CERN Document Server

    Herr, W

    2014-01-01

    One of the most severe limitations in high-intensity particle colliders is the beam-beam interaction, i.e. the perturbation of the beams as they cross the opposing beams. This introduction to beam-beam effects concentrates on a description of the phenomena that are present in modern colliding beam facilities.

  17. Part 1, Angular distribution measurement of beam-foil muonium, Part 2, Muon injection simulation for a new muon g-2 experiment

    International Nuclear Information System (INIS)

    The angular and energy distributions of positive muons μ+ and muonium M produced by the beam-foil method have been measured for the first time. A 7 MeV/c subsurface μ+ beam was delivered to our apparatus from the Stopped Muon Channel at the Los Alamos Clinton P. Anderson Meson Physics Facility (LAMPF). The μ+ formed M by electron capture in a thin Al target foil. A low pressure multi-wire proportional chamber upstream of the target foil was used both as a moderator and as a muon counter. To observe muonium, muons sere swept away by a bending magnet which was placed downstream of the target foil. This magnet was turned off while measuring the μ+ distribution. Beyond the magnetic field, particles were collimated and then stopped by a microchannel plate detector located at various angles to the incident muon beam axis. Two pairs of scintillators mounted above (St) and below (Sb) the MC-P were used to detect the decay positrons to verify from the lifetime spectrum that the particles detected by the MCP are muons. The intensities of μ+ and M emerging from the Al foil at different angles were obtained from both a time-of-flight spectrum and a lifetime spectrum

  18. LIGHT SOURCE: Conceptual design of Hefei Advanced Light Source (HALS) injection system

    Science.gov (United States)

    Zhang, Shan-Cai; Wang, Lin; Feng, Guang-Yao; Wu, Cong-Feng; Li, Wei-Min; Xu, Hong-Liang; Liu, Zu-Ping

    2009-06-01

    The Hefei Advanced Light Source(HALS) is a super low emittance storage ring and has a very short beam life time. In order to run the ring stablely, top-up injection will be necessary. The injection system will greatly affect the quality of beam. This article first gives a physics design of the injecting system. Then the injecting system is tracked under different errors. The responses of storage beam and injecting beam are given in the article.

  19. Charge exchange produced K-shell x-ray emission from Ar16+ in a tokamak plasma with neutral beam injection

    Energy Technology Data Exchange (ETDEWEB)

    Beiersdorfer, P; Bitter, M; Marion, M; Olson, R E

    2004-12-27

    High-resolution spectroscopy of hot tokamak plasma seeded with argon ions and interacting with an energetic, short-pulse neutral hydrogen beam was used to obtain the first high-resolution K-shell x-ray spectrum formed solely by charge exchange. The observed K-shell emission of Ar{sup 16+} is dominated by the intercombination and forbidden lines, providing clear signatures of charge exchange. Results from an ab initio atomic cascade model provide excellent agreement, validating a semiclassical approach for calculating charge exchange cross sections.

  20. High Intensity Beam Test of Low Z Materials for the Upgrade of SPS-to-LHC Transfer Line Collimators and LHC Injection Absorbers

    CERN Document Server

    Maciariello, Fausto; Butcher, Mark; Calviani, Marco; Folch, Ramon; Kain, Verena; Karagiannis, Konstantinos; Lamas Garcia, Inigo; Lechner, Anton; Nuiry, Francois-Xavier; Steele, Genevieve; Uythoven, Jan

    2016-01-01

    In the framework of the LHC Injector Upgrade (LIU) and High-Luminosity LHC (HL-LHC) project, the collimators in the SPS-to LHC transfer lines will undergo important modifications. The changes to these collimators will allow them to cope with beam brightness and intensity levels much increased with respect to their original design parameters: nominal and ultimate LHC. The necessity for replacement of the current materials will need to be confirmed by a test in the High Radiation to Materials (HRM) facility at CERN. This test will involve low Z materials (such as Graphite and 3-D Carbon/Carbon composite), and will recreate the worst case scenario those materials could see when directly impacted by High luminosity LHC (HL-LHC) or Batch Compression Merging and Splitting (BCMS) beams. Thermo-structural simulations used for the material studies and research, the experiment preparation phase, the experiment itself, pre irradiation analysis (including ultrasound and metrology tests on the target materials), the resul...

  1. Dexamethasone Injection

    Science.gov (United States)

    ... lines under the skin skin depressions at the injection site increased body fat or movement to different areas of your body inappropriate happiness difficulty falling asleep or staying asleep extreme ... increased appetite injection site pain or redness Some side effects can ...

  2. Paliperidone Injection

    Science.gov (United States)

    Paliperidone extended-release injections (Invega® Sustenna, Invega® Trinza) are used to treat schizophrenia (a mental illness that ... interest in life, and strong or inappropriate emotions). Paliperidone extended-release injection (Invega® Sustenna) is also used ...

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

    Science.gov (United States)

    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.

  4. Single- and dual-beam in situ irradiations of high-purity iron in a transmission electron microscope: Effects of heavy ion irradiation and helium injection

    International Nuclear Information System (INIS)

    In order to study the effects of 14 MeV neutron irradiation on materials used in the first walls of future fusion reactors, high-purity iron was ion-irradiated with and without helium in the JANNuS facility. Thin foils of high-purity iron were dual-beam irradiated in situ in a transmission electron microscope using 1 MeV Fe+ and 15 keV He+ ions. Several important results regarding dislocation loops and helium bubbles were obtained. For example, it was demonstrated that dislocation loops with a0 〈0 1 0〉 type Burgers vectors are glissile and can move and eliminate at the surface of the thin foil at 500 °C. A comparison of irradiations with and without helium showed that helium atoms reduce the mobility of dislocation loops in pure iron irradiated at 500 °C. Also, we demonstrated that the heterogeneous formation of bubbles inside dislocation loops found previously is also present for helium implantation rates of ∼80 atomic parts per million (appm) He/displacements per atom (dpa)

  5. Aripiprazole Injection

    Science.gov (United States)

    ... pressure, seizures, difficulty swallowing, a high level of fats (cholesterol and triglycerides) in your blood, or a medical condition that may affect you receiving an injection in your arm or buttocks. Tell your doctor ...

  6. Nafcillin Injection

    Science.gov (United States)

    ... injection is in a class of medications called penicillins. It works by killing bacteria.Antibiotics such as ... and pharmacist if you are allergic to nafcillin; penicillins; cephalosporin antibiotics such as cefaclor, cefadroxil, cefazolin, cefdinir, ...

  7. Oxacillin Injection

    Science.gov (United States)

    ... injection is in a class of medications called penicillins. It works by killing bacteria.Antibiotics such as ... and pharmacist if you are allergic to oxacillin; penicillins; cephalosporin antibiotics such as cefaclor, cefadroxil, cefazolin, cefdinir, ...

  8. Ampicillin Injection

    Science.gov (United States)

    ... injection is in a class of medications called penicillins. It works by killing bacteria.Antibiotics such as ... and pharmacist if you are allergic to ampicillin; penicillins; cephalosporin antibiotics such as cefaclor, cefadroxil, cefazolin (Ancef, ...

  9. Olanzapine Injection

    Science.gov (United States)

    ... of interest in life, and strong or inappropriate emotions). Olanzapine injection is used to treat episodes of ... this medication affects you.you should know that alcohol can add to the drowsiness caused by this ...

  10. Aripiprazole Injection

    Science.gov (United States)

    ... of interest in life, and strong or inappropriate emotions). Aripiprazole injection (Abilify) is used to treat episodes ... street drugs or have overused prescription medication or alcohol or has or has ever had diabetes, obsessive ...

  11. Haloperidol Injection

    Science.gov (United States)

    ... of interest in life, and strong or inappropriate emotions). Haloperidol injection is also used to control motor ... this medication affects you.you should know that alcohol can add to the drowsiness caused by this ...

  12. Testosterone Injection

    Science.gov (United States)

    Testosterone cypionate (Depo-Testosterone), testosterone enanthate (Delatestryl), testosterone undecanoate (Aveed), and testosterone pellet (Testopel) are forms of testosterone injection used to treat symptoms of low testosterone in men who have hypogonadism (a ...

  13. Ketorolac Injection

    Science.gov (United States)

    ... of ketorolac by intravenous (into a vein) or intramuscular (into a muscle) injection in a hospital or ... aspirin) such as ketorolac may have a higher risk of having a heart attack or a stroke ...

  14. Busulfan Injection

    Science.gov (United States)

    ... marrow and cancer cells in preparation for a bone marrow transplant. Busulfan is in a class of medications called ... days (for a total of 16 doses) before bone marrow transplant.Busulfan injection may cause seizures during therapy with ...

  15. Fludarabine Injection

    Science.gov (United States)

    ... also sometimes used to treat non-Hodgkin's lymphoma (NHL; cancer that begins in a type of white ... this medication. You should not plan to have children while receiving fludarabine injection or for at least ...

  16. Gemcitabine Injection

    Science.gov (United States)

    ... with surgery. Gemcitabine is also used to treat cancer of the pancreas that has spread to other parts of the ... 4 weeks. When gemcitabine is used to treat cancer of pancreas it may be injected once every week. The ...

  17. Ixekizumab Injection

    Science.gov (United States)

    ... ixekizumab solution before injecting it. Check that the expiration date has not passed and that the liquid ... fever, sweats, or chills, muscle aches, shortness of breath, warm, red, or painful skin or sores on ...

  18. Tesamorelin Injection

    Science.gov (United States)

    ... is colored, cloudy, contains particles, or if the expiration date on the bottle has passed.Never reuse ... swelling of the face or throat shortness of breath difficulty breathing fast heartbeat dizziness fainting Tesamorelin injection ...

  19. Secukinumab Injection

    Science.gov (United States)

    ... secukinumab solution before injecting it. Check that the expiration date has not passed and that the liquid ... fever, sweats, or chills, muscle aches, shortness of breath, warm, red, or painful skin or sores on ...

  20. Basiliximab Injection

    Science.gov (United States)

    ... used with other medications to prevent immediate transplant rejection (attack of the transplanted organ by the immune system of the person receiving the organ) in people who are receiving kidney transplants. Basiliximab injection is in a class of medications ...

  1. Tacrolimus Injection

    Science.gov (United States)

    ... is used along with other medications to prevent rejection (attack of the transplanted organ by the transplant recipient's immune system) in people who have received kidney, liver, or heart transplants. Tacrolimus injection should only ...

  2. Belatacept Injection

    Science.gov (United States)

    ... used in combination with other medications to prevent rejection (attack of a transplanted organ by the immune system of a person receiving the organ) of kidney transplants. Belatacept injection is in a class of medications ...

  3. Ciprofloxacin Injection

    Science.gov (United States)

    ... described in the IMPORTANT WARNING section, stop using ciprofloxacin injection and call your doctor immediately or get emergency medical help: rash hives itching peeling or blistering of the skin ...

  4. Aflibercept Injection

    Science.gov (United States)

    ... diabetes that can lead to vision loss), and diabetic retinopathy (damage to the eyes caused by diabetes). Aflibercept ... your doctor about how long you should continue treatment with aflibercept injection.

  5. Tacrolimus Injection

    Science.gov (United States)

    ... prescribed for other uses; ask your doctor or pharmacist for more information. ... Before receiving tacrolimus injection,tell your doctor and pharmacist if you are allergic to tacrolimus, any other ...

  6. Basiliximab Injection

    Science.gov (United States)

    ... prescribed for other uses; ask your doctor or pharmacist for more information. ... Ask your pharmacist any questions you have about basiliximab injection.It is important for you to keep a written list of ...

  7. On the evening of June 15, 2008, ALICE physicists saw the first tracks at LHC during the first injection test in transfer line TI 2. The Silicon Pixel detector recorded muon tracks produced in the beam dump near Point 2 of the LHC.

    CERN Multimedia

    Manzari, Vito

    2008-01-01

    On the evening of June 15, 2008, ALICE physicists saw the first tracks at LHC during the first injection test in transfer line TI 2. The Silicon Pixel detector recorded muon tracks produced in the beam dump near Point 2 of the LHC

  8. Discovery of stationary operation of quiescent H-mode plasmas with net-zero neutral beam injection torque and high energy confinement on DIII-D

    Science.gov (United States)

    Burrell, K. H.; Barada, K.; Chen, X.; Garofalo, A. M.; Groebner, R. J.; Muscatello, C. M.; Osborne, T. H.; Petty, C. C.; Rhodes, T. L.; Snyder, P. B.; Solomon, W. M.; Yan, Z.; Zeng, L.

    2016-05-01

    Recent experiments in DIII-D [J. L. Luxon et al., in Plasma Physics and Controlled Nuclear Fusion Research 1996 (International Atomic Energy Agency, Vienna, 1987), Vol. I, p. 159] have led to the discovery of a means of modifying edge turbulence to achieve stationary, high confinement operation without Edge Localized Mode (ELM) instabilities and with no net external torque input. Eliminating the ELM-induced heat bursts and controlling plasma stability at low rotation represent two of the great challenges for fusion energy. By exploiting edge turbulence in a novel manner, we achieved excellent tokamak performance, well above the H98y2 international tokamak energy confinement scaling (H98y2 = 1.25), thus meeting an additional confinement challenge that is usually difficult at low torque. The new regime is triggered in double null plasmas by ramping the injected torque to zero and then maintaining it there. This lowers E × B rotation shear in the plasma edge, allowing low-k, broadband, electromagnetic turbulence to increase. In the H-mode edge, a narrow transport barrier usually grows until MHD instability (a peeling ballooning mode) leads to the ELM heat burst. However, the increased turbulence reduces the pressure gradient, allowing the development of a broader and thus higher transport barrier. A 60% increase in pedestal pressure and 40% increase in energy confinement result. An increase in the E × B shearing rate inside of the edge pedestal is a key factor in the confinement increase. Strong double-null plasma shaping raises the threshold for the ELM instability, allowing the plasma to reach a transport-limited state near but below the explosive ELM stability boundary. The resulting plasmas have burning-plasma-relevant βN = 1.6-1.8 and run without the need for extra torque from 3D magnetic fields. To date, stationary conditions have been produced for 2 s or 12 energy confinement times, limited only by external hardware constraints. Stationary operation with

  9. Construction of tangential injection NBI system

    International Nuclear Information System (INIS)

    In the Upgrading of the JT-60, the vacuum vessel has been modified to a larger bore. This larger bore vacuum vessel yields a larger toroidal field ripple in the vicinity of a plasma surface because of closing the toroidal field coils and plasmas. A ripple loss of injected neutral beams, then, estimated to be 30-40% through ripple field in the beam injection with the present NBI system that injects the beam perpendicularly to the plasma. An effective way to decrease the ripple loss in the plasma is to inject the beam tangentially. Meanwhile, it has been determined possible with the JT-60 upgrading to use a horizontal port as a tangential beam injection, because of eliminating a group of outer horizontal poloidal coils which are used as a divertor coil in the former JT-60. The modification from perpendicular beamline to tangential one has been executed in four beamlines out of 14 units. Four tangential beamlines are installed in two beamline tanks which are newly fabricated and positioned co- and counter-injection, respectively. Most of the beamline components are reused except a couple of cancellation coils. The modification to the tangential beamline completed in 1993, and the beam injection experiments with the tangential have been conducted successfully since 1993. (author)

  10. Three dimensional analysis of the pore space in fine-grained Boom Clay, using BIB-SEM (broad-ion beam scanning electron microscopy), combined with FIB (focused ion-beam) serial cross-sectioning, pore network modeling and Wood's metal injection

    Science.gov (United States)

    Hemes, Susanne; Klaver, Jop; Desbois, Guillaume; Urai, Janos

    2014-05-01

    The Boom Clay is, besides the Ypresian clays, one of the potential host rock materials for radioactive waste disposal in Belgium (Gens et al., 2003; Van Marcke & Laenen, 2005; Verhoef et al., 2011). To access parameters, which are relevant for the diffusion controlled transport of radionuclides in the material, such as porosity, pore connectivity and permeability, it is crucial to characterize the pore space at high resolution (nm-scale) and in 3D. Focused-ion-beam (FIB) serial cross-sectioning in combination with high resolution scanning electron microscopy (SEM), pore network modeling, Wood's metal injection and broad-ion-beam (BIB) milling, constitute a superior set of methods to characterize the 3D pore space in fine-grained, clayey materials, down to the nm-scale resolution. In the present study, we identified characteristic 3D pore space morphologies, determined the 3D volume porosity of the material and applied pore network extraction modeling (Dong and Blunt, 2009), to access the connectivity of the pore space and to discriminate between pore bodies and pore throats. Moreover, we used Wood's metal injection (WMI) in combination with BIB-SEM imaging to assess the pore connectivity at a larger scale and even higher resolution. The FIB-SEM results show a highly (~ 90 %) interconnected pore space in Boom Clay, down to the resolution of ~ 3E+03 nm³ (voxel-size), with a total volume porosity of ~ 20 %. Pore morphologies of large (> 5E+08 nm³), highly interconnected pores are complex, with high surface area to volume ratios (shape factors G ~ 0.01), whereas small (areas (REAs) (Hemes et al., 2013).

  11. Measurement and analysis of internal loss and injection efficiency for continuous-wave blue semipolar ( 20 2 ¯ 1 ¯ ) III-nitride laser diodes with chemically assisted ion beam etched facets

    Science.gov (United States)

    Becerra, Daniel L.; Kuritzky, Leah Y.; Nedy, Joseph; Saud Abbas, Arwa; Pourhashemi, Arash; Farrell, Robert M.; Cohen, Daniel A.; DenBaars, Steven P.; Speck, James S.; Nakamura, Shuji

    2016-02-01

    Continuous-wave blue semipolar ( 20 2 ¯ 1 ¯ ) III-nitride laser diodes were fabricated with highly vertical, smooth, and uniform mirror facets produced by chemically assisted ion beam etching. Uniform mirror facets are a requirement for accurate experimental determination of internal laser parameters, including internal loss and injection efficiency, which were determined to be 9 cm-1 and 73%, respectively, using the cavity length dependent method. The cavity length of the uncoated devices was varied from 900 μm to 1800 μm, with threshold current densities ranging from 3 kA/cm2 to 9 kA/cm2 and threshold voltages ranging from 5.5 V to 7 V. The experimentally determined internal loss was found to be in good agreement with a calculated value of 9.5 cm-1 using a 1D mode solver. The loss in each layer was calculated and in light of the analysis several modifications to the laser design are proposed.

  12. Beam-beam effects

    Energy Technology Data Exchange (ETDEWEB)

    Zholents, A.

    1994-12-01

    The term beam-beam effects is usually used to designate different phenomena associated with interactions of counter-rotating beams in storage rings. Typically, the authors speak about beam-beam effects when such interactions lead to an increase of the beam core size or to a reduction of the beam lifetime or to a growth of particle`s population in the beam halo and a correspondent increase of the background. Although observations of beam-beam effects are very similar in most storage rings, it is very likely that every particular case is largely unique and machine-dependent. This constitutes one of the problems in studying the beam-beam effects, because the experimental results are often obtained without characterizing a machine at the time of the experiment. Such machine parameters as a dynamic aperture, tune dependencies on amplitude of particle oscillations and energy, betatron phase advance between the interaction points and some others are not well known, thus making later analysis uncertain. The authors begin their discussion with demonstrations that beam-beam effects are closely related to non linear resonances. Then, they will show that a non linearity of the space charge field is responsible for the excitation of these resonances. After that, they will consider how beam-beam effects could be intensified by machine imperfections. Then, they will discuss a leading mechanism for the formation of the beam halo and will describe a new technique for beam tails and lifetime simulations. They will finish with a brief discussion of the coherent beam-beam effects.

  13. Alirocumab Injection

    Science.gov (United States)

    ... feeding. If you become pregnant while using alirocumab injection, call your doctor. ... Eat a low-fat, low-cholesterol diet. Be sure to follow all exercise and dietary ... at: http://www.nhlbi.nih.gov/health/public/heart/chol/chol_tlc.pdf.

  14. Medroxyprogesterone Injection

    Science.gov (United States)

    ... injection when you are a teenager or young adult. Tell your doctor if you or anyone in your family has osteoporosis; if you have or have ever had any other bone disease or anorexia nervosa (an eating disorder); or if you drink a ...

  15. Botox Injections

    Science.gov (United States)

    ... Contact Us Shopping Cart American Academy of Facial Plastic and Reconstructive Surgery Home Meetings & Courses Find a Surgeon Physicians’ Buyers ... Portal Botox Injections The American Academy of Facial Plastic and Reconstructive Surgery recommends persons considering Botox® treatment to: Check the ...

  16. Ibritumomab Injection

    Science.gov (United States)

    ... have received ibritumomab injection.do not have any vaccinations without talking to your doctor.you should know ... cells) and myelodysplastic syndrome (condition in which blood cells do not ... online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

  17. Tositumomab Injection

    Science.gov (United States)

    ... have received tositumomab injection.do not have any vaccinations without talking to your doctor.you should know ... blood cells), myelodysplastic syndrome (condition in which blood cells do not ... online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

  18. Oxytocin Injection

    Science.gov (United States)

    ... provider immediately: chest pain or difficulty breathing confusion fast or irregular heartbeat severe headache irritation at the injection site If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting ...

  19. Infliximab Injection

    Science.gov (United States)

    ... injection is also sometimes used to treat Behcet's syndrome (ulcers in the mouth and on the genitals and inflammation of various ... runny nose back pain white patches in the mouth vaginal itching, burning, and pain, or other signs of a yeast ...

  20. Four orbit bump and injection software for Indus-2 storage ring

    International Nuclear Information System (INIS)

    The injection into Indus-2 takes place in horizontal plane with two injection septa and four kicker magnets in the injection straight. The symmetric and asymmetric orbit bumps generation is required to accept the injected beam. The bump simulation has been done using accelerator toolbox and a graphical user interface has been developed in MATLAB environment. We describe the injection system and software with graphical user interface (GUI) to generate an orbit bump to inject the beam into Indus-2. (author)

  1. Innovative Drug Injection via Laser Induced Plasma

    Science.gov (United States)

    Han, Tae-hee; Yoh, Jack J.

    2010-10-01

    A laser based needle-free liquid drug injection device has been developed. A laser beam is focused inside the liquid contained in the rubber chamber of micro scale. The focused laser beam causes explosive bubble growth and the sudden volume increase in a sealed chamber drives a microjet of liquid drug through the micronozzle. The exit diameter of the nozzle is 125 um and the injected microjet reaches an average velocity of 264 m/s. This device adds the time-varying feature of microjet to the current state of liquid injection for drug delivery.

  2. Injection and extraction for cyclotrons

    CERN Document Server

    Kleeven, W

    2006-01-01

    The main design goals for beam injection are explained and special problems related to a central region with internal ion source are considered. The principle of a PIG source is addressed. The issue of vertical focusing in the cyclotron centre is briefly discussed. Several examples of numerical simulations are given. Different ways of (axial) injection are briefly outlined. A proposal for a magnetostatic axial inflector is given. Different solutions for beam extraction are treated. These include the internal target, extraction by stripping, resonant extraction using a deflector and self-extraction. The different ways of creating a turn-separation are explained. The purpose of different types of extraction devices such as harmonic coils, deflectors and gradient corrector channels are outlined. Several illustrations are given in the form of photographs and drawings.

  3. Development of target injection and tracking for IFE in Japan

    International Nuclear Information System (INIS)

    The study of target injection, detection, measurement of laser focal point, and laser beam steering have started under co-research in Japan. The smooth-bore gas gun is developed for accurate injection. The applications of divergent laser beam and Arago spot are described for accurate measurement of target position and laser focal point. Magnetic lens for target trajectory adjustment by centering force is proposed. The piezoelectric actuator driven mirror is studied for laser beam steering device. (author)

  4. Beam Stability of the LHC Beam Transfer Line TI8

    CERN Document Server

    Wenninger, Jörg; Kain, Verena; Uythoven, Jan

    2005-01-01

    Injection of beam into the LHC at 450 GeV/c proceeds over two 2.7 km long transfer lines from the SPS. The small aperture of the LHC at injection imposes tight constraints on the stability of the beam transfer. The first transfer line TI 8 was commissioned in the fall of 2004 with low intensity beam. Since the beam position monitor signal fluctuations were dominated by noise with low intensity beam, the beam stability could not be obtained from a simple comparison of consecutive trajectories. Instead model independent analysis (MIA) techniques as well as scraping on collimators were used to estimate the intrinsic stability of the transfer line. This paper presents the analysis methods and the resulting stability estimates.

  5. Vertical Beam Size Measurement by Streak Camera under Colliding and Single Beam Conditions in KEKB

    CERN Document Server

    Ikeda, Hitomi; Fukuma, Hitoshi; Funakoshi, Yoshihiro; Hiramatsu, Shigenori; Mitsuhashi, Toshiyuki; Ohmi, Kazuhito; Uehara, Sadaharu

    2005-01-01

    Beam behavior of KEKB was studied by measurement of the beam size using a streak camera. Effect of the electron-cloud and the parasitic collision on the vertical beam size was examined in beam collision. We intentionally injected a test bunch of positrons after 2 rf buckets of a bunch to enhance the electron cloud effect and changed electron beam conditions to see the beam-beam effect. The beam size was also measured with a single positron beam and compared with that during collision. The result of the measurement is reported in this paper.

  6. Application of Diamond Based Beam Loss Monitors

    OpenAIRE

    Hempel, Maria

    2013-01-01

    The LHC has an operational stored energy of 130MJ per beam. Only a small percentage of beam losses in the LHC equipment can damage material or lead to magnet quenches. Therefore, it is important to monitor different types of beam losses, e.g. scattering on residual gas particles, UFOs, collisions and injection losses. A detailed understanding of beam loss mechanisms is necessary to reduce them and ensure save operation. Two different beam loss monitors are installed in the LHC tunnel: ionizat...

  7. Beam catcher/dump

    International Nuclear Information System (INIS)

    A simple, low cost aperture limiting device with an absorber block has been developed and installed in the AGS ring at Brookhaven National Laboratory. The device intercepts injection tails, transition losses, and the inward spiraling beam of an aborted accelerations or extraction cycle. The resultant consolidation of losses at one point reduces activation of components around the ring and radiation exposure to personnel

  8. Beam Transport in Toroidal Magnetic Field

    CERN Document Server

    Joshi, N; Meusel, O; Ratzinger, U

    2016-01-01

    The concept of a storage ring with toroidal magnetic field was presented in the two previous EPAC conferences. Here we report the first results of experiments performed with beam transport in toroidal magnetic fields and details of the injection system. The beam transport experiments were carried out with 30 degree toroidal segments with an axial magnetic field of 0.6T. The multi turn injection system relies on a transverse injection coil together with an electric kicker system.

  9. Fields in multilayer beam tubes

    International Nuclear Information System (INIS)

    Equations are presented for calculating the fields from a bunched beam that penetrate into the layers of a beam tube of circular cross section. Starting from the radial wave impedance of an outer surface, the wave functions in inner layers are calculated numerically to obtain field strengths or the longitudinal beam impedance. Examples of a vertex-detector region and of an injection kicker are given

  10. Beam Transfer and Machine Protection

    CERN Document Server

    Kain, V

    2016-01-01

    Beam transfer, such as injection into or extraction from an accelerator, is one of the most critical moments in terms of machine protection in a high-intensity machine. Special equipment is used and machine protection aspects have to be taken into account in the design of the beam transfer concepts. A brief introduction of the principles of beam transfer and the equipment involved will be given in this lecture. The main concepts of machine protection for injection and extraction will be presented, with examples from the CERN SPS and LHC.

  11. The RHIC injection kicker

    International Nuclear Information System (INIS)

    Beam transfer from the AGS to RHIC is performed in single-bunch mode. Close spacing of the bunches in the collider requires an injection kicker with a rise time of <90 nsec, suggesting adoption of a travelling wave structure. The required vertical kick of 0.186 t·m is provided by 4 magnets, each 1.12 m long with a 48.4 x 48.4 mm aperture and operated at 1.6 kA. The kicker is constructed as a open-quotes Cclose quotes cross section magnet, in which ferrite and high-permittivity dielectric sections alternate. The dielectric blocks provide the capacity necessary for the nominally 25 Ω characteristic impedance of the travelling wave structure, but impose the practical limit on the peak voltage, and thus current, achievable. Computer studies to minimize local electric field enhancements resulted in a configuration capable of holding ∼ 50 kV, with adequate safety margin over the nominal 40 kV. Equivalent circuit analysis indicated the possibility of lowering the nominal voltage by operating mismatched into 20 Ω terminations without degrading the pulse shape. In this paper, the experience gained in the fabrication of the production units and the results from various single-unit tests and operation of four kickers with beam in the open-quotes Sextant Testclose quotes are reported

  12. A computer code for computing the beam profiles in the NBI beam line 'BEMPROF'

    International Nuclear Information System (INIS)

    A computer code was developed which can compute the beam profiles and the percentage heat loadings on the various components in the NBI beam line such as the beam target, the beam limiters and the calorimeter. The geometrical injection efficiency of NBI and the heat input pattern on the counter surface of the injection port of the torus can also be computed. The major feature of this code is that the effects of the beamlet intensity distribution, the beamlet deflection, the beam screening by the upstream limiters and also the plasma density distribution and the divergence angle distribution over the beam extraction area can be taken into account. (author)

  13. Control And Transport Of Intense Electron Beams

    CERN Document Server

    Li, H

    2004-01-01

    The transport of intense beams for advanced accelerator applications with high-intensity beams such as heavy-ion inertial fusion, spallation neutron sources, and intense light sources requires tight control of beam characteristics over long distances. The University of Maryland Electron Ring (UMER), which uses low energy, high current electron beams to model the transport physics of intense space-charge-dominated beams, employs real-time beam characterization and control in order to optimize beam quality throughout the strong focusing lattice. We describe in this dissertation the main beam control techniques used in UMER, which include optimal beam steering by quadrupole scans, beam rotation correction using a skew corrector, rms envelope matching and optimization, empirical envelope matching, beam injection, and phase space reconstruction using a tomographic method. Using these control techniques, we achieved the design goals for UMER. The procedure is not only indispensable for optimum beam transport over l...

  14. Nanostructuring steel for injection molding tools

    DEFF Research Database (Denmark)

    Al-Azawi, A.; Smistrup, Kristian; Kristensen, Anders

    2014-01-01

    The production of nanostructured plastic items by injection molding with ridges down to 400 nm in width, which is the smallest line width replicated from nanostructured steel shims, is presented. Here we detail a micro-fabrication method where electron beam lithography, nano-imprint lithography and...... ion beam etching are combined to nanostructure the planar surface of a steel wafer. Injection molded plastic parts with enhanced surface properties, like anti-reflective, superhydrophobic and structural colors can be achieved by micro-and nanostructuring the surface of the steel molds. We investigate...... replica has been produced by injection molding with good structure transfer fidelity. Thus we have demonstrated that by utilizing well-established fabrication techniques, nanostructured steel shims that are used in injection molding, a technique that allows low cost mass fabrication of plastic items, are...

  15. LEP beam separator at L3

    CERN Multimedia

    1989-01-01

    During injection and acceleration, separators like this were used to keep the electron and positron beams apart while they travelled in the vacuum chamber. When the beams reached maximum energy the separators at the experiments were turned off, allowing the beams to collide. This one was located near the L3 experiment, whose huge red solenoid magnet can be seen in the background.

  16. BEAM TRANSFER LINES FOR THE SPALLATION NEUTRON SOURCE.

    Energy Technology Data Exchange (ETDEWEB)

    RAPARIA,D.; LEE,Y.Y.; WENG,W.T.; WEI,J.

    2002-04-08

    Beam transfer lines for the Spallation Neutron Source (SNS) are designed to have low beam losses for hand on maintenance while satisfying the facility footprint requirements. There are two main beam transfer lines, High Energy Beam Transport (HEBT) line which connect super conducting linac to the accumulator ring and Ring to Target Beam transport (RTBT) which transfers beam from accumulator ring to the target. HEBT line not only transfer the beam from linac to ring but also prepare beam for ring injection, correct the energy jitter from the linac, provide required energy spread for the ring injection, clean the transverse and longitudinal halo particles from the beam, determine the linac beam quality, and provide the protection to the accumulator ring. RTBT line transport the beam from ring to target while fulfilling the target requirements of beam size, maximum current density, beam moment on the target in case of ring extraction kicker failure. and protect the target from the ring fault conditions.

  17. Performance of the ALS injection system

    International Nuclear Information System (INIS)

    The authors started commissioning the Advanced Light Source (ALS) storage ring on January 11, 1993. The stored beam reached 60 mA on March 24, 1993 and 407 mA on April 9, 1993. The fast pace of storage ring commissioning can be attributed partially to the robust injection system. In this paper they describe the operating characteristics of the ALS injection system

  18. Tranverse-field focussing beam transport experiment

    International Nuclear Information System (INIS)

    The Transverse-Field Focussing (TFF) beam transport and accelerator system developed at LBL is useful for negative-ion -based neutral beam injection due to its unique differential pumping and neutron shielding properties. We have tested the first module of our TFF system transporting H- beams up to 80 keV beam energy. The testing addressed the most crucial physics and engineering issues involved in the principles of a TFF system including beam compression and differential gas pumping. At optimum perveance, the present design will transport 4 A/m of H- beam at 80 keV beam energy

  19. Preliminary Results of Ion Beam Extraction Tests on EAST Neutral Beam Injector

    Institute of Scientific and Technical Information of China (English)

    胡纯栋

    2012-01-01

    The neutral beam injection (NBI) system is one of the most important auxiliary plasma heating and current driving methods for fusion device. A high power ion beam of 3 MW with 80 keV beam energy in 0.5 s beam duration and a long pulse ion beam of 4 s with 50 keV beam energy ion beam extraction were achieved on the EAST neutral beam injector on the teststand. The preliminary results show that the EAST-NBI system was developed successfully on schedule.

  20. Injection envelope matching in storage rings

    International Nuclear Information System (INIS)

    The shape and size of the transverse phase space injected into a storage ring can be deduced from turn-by-turn measurements of the transient behavior of the beam envelope in the ring. Envelope oscillations at 2 x the β-tron frequency indicate the presence of a β-mismatch, while envelope oscillations at the β-tron frequency are the signature of a dispersion function mismatch. Experiments in injection optimization using synchrotron radiation imaging of the beam and a fast-gated camera at the SLC damping rings are reported

  1. Nonlinear beam-beam resonances

    International Nuclear Information System (INIS)

    Head-on collisions of bunched beams are considered, assuming the two colliding beams have opposite charges. A few experimental observations are described. The single resonance analysis is developed that is applicable to the strong-weak case of the beam-beam interaction. In this case, the strong beam is unperturbed by the beam-beam interaction; motions of the weak beam particles are then analyzed in the presence of the nonlinear electromagnetic force produced by the strong beam at the collision points. The coherent motions of the two coupled strong beams are shown to exhibit distinct nonlinear resonance behavior. 16 refs., 22 figs

  2. Electron beam electromagnetic field interaction in one-dimensional coaxial vircator

    Science.gov (United States)

    Shao, H.; Liu, G. Z.; Yang, Z. F.

    2005-10-01

    A one-dimensional model of the interaction between an injected electron beam and an electromagnetic (EM) field inside a coaxial vircator is presented. The effects of the injected electron beam energy spread, anode absorption rate, feedback and injected current premodulation are analyzed. The EM-gains of interaction between the electron beam and TM01, TE11 modes are derived and discussed.

  3. Pulsed magnetic field for PHERMEX-injected circular accelerator

    International Nuclear Information System (INIS)

    The PHERMEX accelerator is a standing wave, 50 MHz rf linear accelerator. The rf fields in three cavities are pulsed for a period of 3 ms. The experiments described are directed toward studying injection and trapping of electron rings at modes field strengths (approximately 1 T). A single 200 ns beam macropulse is to be injected transverse to a solenoidal field, which is tilted at a small angle relative to the beam normal so that a beam micropulse does not return and strike the injection point. The pulsed field coils and vacuum chamber are reported under construction, and the capacitor bank being tested

  4. Penicillin G Procaine Injection

    Science.gov (United States)

    Penicillin G procaine injection is used to treat certain infections caused by bacteria. Penicillin G procaine injection should not be used to ... early in the treatment of certain serious infections. Penicillin G procaine injection is in a class of ...

  5. Preliminary Experimental Study of Ion Beam Extraction of EAST Neutral Beam Injector

    Institute of Scientific and Technical Information of China (English)

    XU Yong-Jian; HU Chun-Dong; LIU Sheng; XIE Ya-Hong; LIANG Li-Zhen; JIANG Cai-Chao

    2012-01-01

    Neutral beam injection is recognized as one of the most effective means for plasma heating.The preliminary data of ion beam extraction is obtained on the EAST neutral beam injector test-stand.Beam extraction from the ion source of EAST-NBI is verified by measuring the beam current with a Faraday cup and by analyzing the results obtained by means of water calorimetric measurement on the temperature rises of water cooling the accelerator electrodes.

  6. Design of H- injection system for FFAG accelerator at KURRI

    International Nuclear Information System (INIS)

    In Kyoto University Research Reactor Institute (KURRI), a neutron source based on the accelerator driven subcritical reactor (ADSR) concept has been proposed in 1996. Aiming to demonstrate the basic feasibility of ADSR, proton Fixed Field Alternating Gradient (FFAG) accelerator complex as a neutron production driver has been constructed and the ADSR experiment has been started in March 2009. In order to upgrade beam intensity, multi-turn charge exchange injection system for scaling FFAG accelerator is being studied. The injection scheme is converted from orbit shift single-turn injection to H- multi-turn injection. The method to escape the stripping foil is orbit shift by rf acceleration. The 11 MeV H- beam is injected from linac and is accelerated up to 100MeV in FFAG main ring. In this paper, the detail of injection system is described and feasibility of such a low energy H- injection system is discussed. (author)

  7. Premature beam dumps in 2011

    CERN Document Server

    Albert, Markus

    2012-01-01

    The statistical analysis of all non-programmed beam dumps during the 2011 proton run is presented. The selection criteria of fills that got considered were that the beam intensity of each of the two beams exceeded at least 1e12 particles per beam in order to exclude all probe beam dumps and most of the MPS test dumps. A distribution of beam dump causes by system is shown, as well as the time it took to re-establish injection after a non-programmed dump for fills which made it into STABLE BEAMS. This was done in an attempt to evaluate the cost of those non-programmed dumps in terms of time.

  8. Multi-turn injection into the FFAG accelerator at Kyushu University

    International Nuclear Information System (INIS)

    A multi-turn injection system for the Fixed Field Alternating Gradient accelerator at Kyushu University has been developed to increase the beam intensity. Bump magnets designed to consist of air core coils of polyamide-imide-insulated wires were installed in the FFAG accelerator. The beam injection test experiment results that the system can inject a beam in 4 turns into the FFAG accelerator. (author)

  9. BATMAN beam properties characterization by the beam emission spectroscopy diagnostic

    Science.gov (United States)

    Bonomo, F.; Ruf, B.; Barbisan, M.; Cristofaro, S.; Schiesko, L.; Fantz, U.; Franzen, P.; Pasqualotto, R.; Riedl, R.; Serianni, G.; Wünderlich, D.

    2015-04-01

    The ITER neutral beam heating systems are based on the production and acceleration of negative ions (H/D) up to 1 MV. The requirements for the beam properties are strict: a low core beam divergence (BATMAN (BAvarian Test MAchine for Negative ions) allows for deepening the knowledge of the determination of the beam properties. One of the diagnostics routinely used to this purpose is the Beam Emission Spectroscopy (BES): the Hα light emitted in the beam is detected and the corresponding spectra are evaluated to estimate the beam divergence and the stripping losses. The BES number of lines of sight in BATMAN has been recently increased: five horizontal lines of sight providing a vertical profile of the beam permit to characterize the negative ion beam properties in relation to the source parameters. Different methods of Hα spectra analysis are here taken into account and compared for the estimation of the beam divergence and the amount of stripping. In particular, to thoroughly study the effect of the space charge compensation on the beam divergence, an additional hydrogen injection line has been added in the tank, which allows for setting different background pressure values (one order of magnitude, from about 0.04 Pa up to the source pressure) in the beam drift region.

  10. Monitoring the extracted proton beam at the SPS

    CERN Multimedia

    1977-01-01

    Fluorescent screens in front of the target positions allow a precise adjustement in front of them. A similar photo was recorded at the beam dump at the beam injection into the SPS, see Weekly Bulletin of April 1976.

  11. Crystal Collimation with protons at injection energy

    CERN Document Server

    Rossi, Roberto; Masi, Alessandro; Mirarchi, Daniele; Montesano, Simone; Redaelli, Stefano; Valentino, Gianluca; Scandale, Walter; CERN. Geneva. ATS Department

    2015-01-01

    During this MD, performed on August 30th, 2015, bent silicon crystals were tested with protons beams for a possible usage of crystal-assisted collimation. Tests were performed at injection energy, using both horizontal and vertical crystals, providing a crucial test of the hardware for precise crystal angle adjustments (goniometers). Proton channeling was observed for the first time with LHC beams and the channeled beams were probed with scans performed with secondary collimators. Measurements of cleaning efficiency of a crystal-based collimation system were also performed.

  12. Vertical distributor in the Booster injection line

    CERN Multimedia

    1979-01-01

    The beam from the 50 MeV linac filled the 4 rings of the PS Booster(originally 800 MeV, now 1.4 GeV) one after the other (in multiturn injection). A fast-switchable vertical steering magnet, the "distributor", directed the beam first to the top ring (nb.4), and after a preset number of turns to next lower ring, and so on. After filling the bottom ring, the tail of the linac beam was directed into a dump.

  13. On injection of polarized electrons into a cyclic accelerator

    International Nuclear Information System (INIS)

    A magnetic system, which allows to transform the longitudinal polarization of electron beams into a transverse one for definite values of energy of particles when injected into a cyclic accelerator is considered. 2 figs

  14. Nanostructuring steel for injection molding tools

    DEFF Research Database (Denmark)

    Al-Azawi, A.; Smistrup, Kristian; Kristensen, Anders

    2014-01-01

    ion beam etching are combined to nanostructure the planar surface of a steel wafer. Injection molded plastic parts with enhanced surface properties, like anti-reflective, superhydrophobic and structural colors can be achieved by micro-and nanostructuring the surface of the steel molds. We investigate...

  15. Development of beam flattening system using non-linear beam optics at J-PARC/JSNS

    International Nuclear Information System (INIS)

    As increasing in the beam power, the damage of the target becomes serious. Especially for a target for high power short pulse spallation neutron source, the damage due to the proton beam on the target vessel for liquid metal target such as mercury is reported to be proportional of 4th power of the peak intensity of the proton beam. Reduction of the peak intensity is important for the beam injection system. At the JSNS, beam profile can be described by the clear Gaussian functions. To reduce peak intensity, we have developed a beam transport system by non-linear beam optics using octupole magnets. (author)

  16. Propagation and beam-plasma interactions of the EDI beam

    International Nuclear Information System (INIS)

    An electron drift instrument (EDI), proposed for the Cluster mission, would measure electric fields, magnetic field gradients, and magnetic field strengths in the magnetospheric plasma. The experiments involve injecting two beams of test electrons into the magnetosphere perpendicular to the ambient magnetic field. Forces due to the ambient electric and magnetic fields return the beams to two dedicated detectors on the spacecraft. For typical magnetospheric electric and magnetic fields and a beam energy of 1 keV, the electron gyroradius is on the order of kilometers, the gyroperiod is milliseconds, and the drift distance in one gyroperiod is a few meters. This paper reports on analyses of electron beam propagation and beam-plasma interaction for the EDI beams. 27 refs

  17. A Beam Shape Oscillation Monitor for HERA

    International Nuclear Information System (INIS)

    The perfect matching of the injecting beam phase space with the accelerator lattice is a very important problem. Its successful solution allows excluding possible mismatch emittance blow-up and worsening of the beam characteristics, that is necessary to get the highest possible luminosity in hadron accelerators. The mismatch can be controlled by measuring sizes oscillation on the first revolutions of the injected beam at a certain orbit point. Designed for this purpose the construction, acquisition electronics, software controlling of the operation and data processing of such a monitor are described. A first test result with beam is presented

  18. A Beam Shape Oscillation Monitor for HERA

    Science.gov (United States)

    Afanasyev, O. V.; Baluev, A. B.; Gubrienko, K. I.; Merker, E. A.; Wittenburg, K.; Krouptchenkow, I.

    2006-11-01

    The perfect matching of the injecting beam phase space with the accelerator lattice is a very important problem. Its successful solution allows excluding possible mismatch emittance blow-up and worsening of the beam characteristics, that is necessary to get the highest possible luminosity in hadron accelerators. The mismatch can be controlled by measuring sizes oscillation on the first revolutions of the injected beam at a certain orbit point. Designed for this purpose the construction, acquisition electronics, software controlling of the operation and data processing of such a monitor are described. A first test result with beam is presented.

  19. Bessel Beams

    OpenAIRE

    McDonald, Kirk T

    2000-01-01

    Scalar Bessel beams are derived both via the wave equation and via diffraction theory. While such beams have a group velocity that exceeds the speed of light, this is a manifestation of the "scissors paradox" of special relativty. The signal velocity of a modulated Bessel beam is less than the speed of light. Forms of Bessel beams that satisfy Maxwell's equations are also given.

  20. Studies on Transverse Painting for H- Injection into the PSB

    CERN Document Server

    Bracco, C; Fowler, T; Goddard, B; Grawer, G; Lallement, J B; Martini, M; Weterings, W

    2011-01-01

    Linac4 will inject 160 MeV H- ions into the CERN PS Booster (PSB). This will allow to reduce space charge effects and increase beam intensity but will require a substantial upgrade of the injection region. The PSB has to provide beam to several users with different requirements in terms of beam intensity and emittance. Four kicker magnets (KSW) will be used to accomplish painting in the horizontal phase space to match the injected beams to the required emittances. Multiple linear functions, with varying slopes for each user, have been defined for the KSW generators waveforms according to detailed beam dynamic studies for all target intensities and emittances. Preliminary studies have been carried out to evaluate how to obtain the required vertical emittance and the option of a transverse painting, also in the vertical plane, is explored.

  1. Beam catcher/dump

    International Nuclear Information System (INIS)

    A simple, low cost aperture limiting device with an absorber block has been developed and installed in the AGS ring at Brookhaven National Laboratory. The device intercepts injection tails, transition losses, and the inward spiraling beam of an aborted acceleration or extraction cycle. The resultant consolidation of losses at one point reduces activation of components around the ring and radiation exposure to personnel. 3 refs., 6 figs

  2. Injection quality measurements with diamond based particle detectors

    CERN Document Server

    Stein, Oliver; CERN. Geneva. ATS Department

    2016-01-01

    During the re-commissioning phase of the LHC after the long shutdown 1 very high beam losses were observed at the TDI during beam injection. The losses reached up to 90% of the dump threshold. To decrease the through beam losses induced stress on the accelerator components these loss levels need to be reduced. Measurements with diamond based particle detectors (dBLMs), which have nano-second time resolution, revealed that the majority of these losses come from recaptured SPS beam surrounding the nominal bunch train. In this MD the injection loss patterns and loss intensities were investigated in greater detail. Performed calibration shots on the TDI (internal beam absorber for injection) gave a conversion factor from impacting particles intensities to signal in the dBLMs (0.1Vs/109 protons). Using the SPS tune kicker for cleaning the recaptured beam in the SPS and changing the LHC injection kicker settings resulted in a reduction of the injection losses. For 144 bunch injections the loss levels were decreased...

  3. On Maximal Injectivity

    Institute of Scientific and Technical Information of China (English)

    Ming Yi WANG; Guo ZHAO

    2005-01-01

    A right R-module E over a ring R is said to be maximally injective in case for any maximal right ideal m of R, every R-homomorphism f : m → E can be extended to an R-homomorphism f' : R → E. In this paper, we first construct an example to show that maximal injectivity is a proper generalization of injectivity. Then we prove that any right R-module over a left perfect ring R is maximally injective if and only if it is injective. We also give a partial affirmative answer to Faith's conjecture by further investigating the property of maximally injective rings. Finally, we get an approximation to Faith's conjecture, which asserts that every injective right R-module over any left perfect right self-injective ring R is the injective hull of a projective submodule.

  4. BEAM CONTAINMENT SYSTEM FOR NSLS-II

    International Nuclear Information System (INIS)

    The shielding design for the NSLS-II will provide adequate protection for the full injected beam loss in two periods of the ring around the injection point, but the remainder of the ring is shielded for lower losses of (le) 10% full beam. This will require a system to insure that beam losses don't exceed these levels for a period of time that could cause excessive radiation levels outside the shield walls. This beam containment system will measure, provide a level of control and alarm indication of the beam power losses along the beam path from the source (e-gun, linac) thru the injection system and the storage ring. This system will consist of collimators that will provide limits to (and potentially to measure) the beam miss-steering and control the loss points of the charge and monitors that will measure the average beam current losses along the beam path and alarm when this beam power loss exceeds the level set by the shielding specifications. This will require some new ideas in beam loss detection capability and collimation. The initial planning and R and D program will be presented.

  5. Equipment for ion beam production

    International Nuclear Information System (INIS)

    An equipment has been designed to extend the scope of control of ion beam flux for an intensive ion beam source used for plasma injection in magnetic vessels. The control equipment is connected to the electromagnet power supply. A consumption regulator is fitted in the operating gas supply to the hollow cathode of the ion source. A circuit is also included for discharge voltage maintenance consisting of a control element and a discharge voltage pick-up. (M.D.). 1 fig

  6. Beam stacking experiments at TARN

    International Nuclear Information System (INIS)

    After the first success of beam injection in TARN, August of 1979, beam experiments have been performed in succession to show the overall stacking number of around -- 300 turns, 15 RF stackings and 20 multi-turns. These results are in the close agreements with the theoretical calculations and we are now convinced that the stacking method used at TARN is quite useful for the accelerators of protons and heavy ions. (author)

  7. Optimization of the Multi-turn Injection Efficiency for Medical Synchrotron

    CERN Document Server

    Kim, J; Yoon, M

    2016-01-01

    We present a method for optimization of the multi-turn injection effciency for medical synchrotron. We show that for given injection energy the injection efficiency can be greatly enhanced by choosing transverse tunes appropriately as well as optimizing the injection bump and the number of turns required for beam injection. We verify our study by applying the method to the Korea Heavy Ion Medical Accelerator (KHIMA) synchrotron which is currently built at the campus of Dongnam Institute of Radiological and Medical Sciences (DIRAMS) in Busan, Korea. First the frequency map analysis is performed with the help of ELEGANT and ACCSIM codes. The tunes which yield the good injection efficiency are then selected. With these tunes the injection bump and the number of turns required for injection are then optimized by tracking a number of particles up to one thousand turns after injection beyond which there is no further beam loss. Results for optimization of the injection efficiency for proton ion are presented.

  8. Upgrade of the LHC Injection Kicker Magnets

    CERN Document Server

    Barnes, M J; Baglin, V; Bregliozzi, G; Caspers, F; Calatroni, S; Day, H; Ducimetière, L; Garlaschè, M; Gomes Namora, V; Jimenez, J M; Magnin, N; Mertens, V; Métral, E; Salvant, B; Taborelli, M; Uythoven, J; Weterings, W

    2013-01-01

    Two LHC injection kicker systems, each comprising 4 magnets per ring, produce a kick of 1.3 T·m with a rise-time of less than 900 ns and a flattop ripple of less than ±0.5%. A beam screen is placed in the aperture of each magnet, to provide a path for the image current of the LHC beam and screen the ferrite yoke against wake fields. The screen consists of a ceramic tube with conductors in the inner wall. The initially implemented beam screen ensured a low rate of electrical breakdowns and an adequately low beam coupling impedance. Operation with increasingly higher intensity beams, stable for many hours at a time, has resulted in substantial heating of the ferrite yoke, sometimes requiring cool-down over several hours before the LHC can be refilled. During the long shutdown in 2013/2014 all eight kicker magnets will be upgraded with an improved beam screen and an increased emissivity of the vacuum tank. In addition equipment adjacent to the injection kickers and various vacuum components will be modified to...

  9. Beam emittance reduction during operation of Indus-2

    Science.gov (United States)

    Fakhri, Ali Akbar; Kant, Pradeep; Ghodke, A. D.; Singh, Gurnam

    2015-11-01

    Indus-2 storage ring is a 2.5 GeV third generation synchrotron radiation source. This source was commissioned using a moderate optics. Beam injection was accomplished using an off momentum electron beam to avoid difficulties faced in storage of beam at 550 MeV. The injection procedure and relevant beam dynamical studies are discussed. The switch over from the moderate optics to low emittance optics is done at 2.5 GeV after storing the electron beam. The procedure evolved to reduce the beam emittance and its implementation during the operation is discussed.

  10. Beam emittance reduction during operation of Indus-2.

    Science.gov (United States)

    Fakhri, Ali Akbar; Kant, Pradeep; Ghodke, A D; Singh, Gurnam

    2015-11-01

    Indus-2 storage ring is a 2.5 GeV third generation synchrotron radiation source. This source was commissioned using a moderate optics. Beam injection was accomplished using an off momentum electron beam to avoid difficulties faced in storage of beam at 550 MeV. The injection procedure and relevant beam dynamical studies are discussed. The switch over from the moderate optics to low emittance optics is done at 2.5 GeV after storing the electron beam. The procedure evolved to reduce the beam emittance and its implementation during the operation is discussed. PMID:26628127

  11. Beam emittance reduction during operation of Indus-2

    Energy Technology Data Exchange (ETDEWEB)

    Fakhri, Ali Akbar, E-mail: fakhri@rrcat.gov.in; Kant, Pradeep; Ghodke, A. D.; Singh, Gurnam [Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India)

    2015-11-15

    Indus-2 storage ring is a 2.5 GeV third generation synchrotron radiation source. This source was commissioned using a moderate optics. Beam injection was accomplished using an off momentum electron beam to avoid difficulties faced in storage of beam at 550 MeV. The injection procedure and relevant beam dynamical studies are discussed. The switch over from the moderate optics to low emittance optics is done at 2.5 GeV after storing the electron beam. The procedure evolved to reduce the beam emittance and its implementation during the operation is discussed.

  12. Beam emittance reduction during operation of Indus-2

    International Nuclear Information System (INIS)

    Indus-2 storage ring is a 2.5 GeV third generation synchrotron radiation source. This source was commissioned using a moderate optics. Beam injection was accomplished using an off momentum electron beam to avoid difficulties faced in storage of beam at 550 MeV. The injection procedure and relevant beam dynamical studies are discussed. The switch over from the moderate optics to low emittance optics is done at 2.5 GeV after storing the electron beam. The procedure evolved to reduce the beam emittance and its implementation during the operation is discussed

  13. The LHC injection kicker magnet

    CERN Document Server

    Ducimetière, Laurent; Barnes, M J; Wait, G D

    2003-01-01

    Proton beams will be injected into LHC at 450 GeV by two kicker magnet systems, producing magnetic field pulses of approximately 900 ns rise time and up to 7.86 s flat top duration. One of the stringent design requirements of these systems is a flat top ripple of less than ± 0.5%. Both injection systems are composed of 4 travelling wave kicker magnets of 2.7 m length each, powered by pulse forming networks (PFN's). To achieve the required kick strength of 1.2 Tm, a low characteristic impedance has been chosen and ceramic plate capacitors are used to obtain 5 Omega. Conductive stripes in the aperture of the magnets limit the beam impedance and screen the ferrite. The electrical circuit has been designed with the help of PSpice computer modelling. A full size magnet prototype has been built and tested up to 60 kV with the magnet under ultra high vacuum (UHV). The pulse shape has been precision measured at a voltage of 15 kV. After reviewing the performance requirements the paper presents the magnet...

  14. Enhancing the accelerated beam current in the booster synchrotron by optimizing the transport line beam propagation

    Indian Academy of Sciences (India)

    Saini R S; Tyagi Y; Ghodke A D; Puntambekar T A

    2016-04-01

    In this paper, we present the results of transverse beam emittance and twiss parameter measurement of an electron beam, delivered by a 20 MeV microtron which is used as a pre-injector system for a booster synchrotron in the Indus Accelerator Facility at RRCAT Indore. Based on these measured beam parameters, beam optics of a transport line was optimized and its results are alsodiscussed in this paper. This beam transport line is used to transport the electron beam from the 20MeV microtron to the booster synchrotron. The booster synchrotron works as a main injector for Indus-1 and Indus-2 synchrotron radiation facilities. To optimize the beam optics of a transport linefor proper beam transmission through the line as well as to match the beam twiss parameters at the beam injection point of another accelerator, it is necessary to know the transverse beam emittance and twiss parameters of the beam coming from the first one. A MATLAB-based GUI program has been developed to calculate the beam emittance and twiss parameters, using quadrupole scanmethod. The measured parameters have been used for beam transport line optimization and twiss parameters matching at booster injection point. After this optimization, an enhancement of ∼50% beam current has been observed in the booster synchrotron.

  15. AA injection kicker in its tank

    CERN Multimedia

    1980-01-01

    For single-turn injection of the antiprotons, a septum at the end of the injection line made the beam parallel to the injection orbit, and a quarter of a betatron-wavelength downstream a fast kicker corrected the angle. Kicker type: lumped delay line. PFN voltage 56 kV. Bending angle 7.5 mrad; kick-strength 0.9 Tm; fall-time 95%-5% in 150 ns. The injection orbit is to the left, the stack orbit to the far right. A fast shutter near the central orbit had to be closed before the kicker fired, so as to protect the stack core from being shaken by the kicker's fringe field. The shutter is shown in closed position.

  16. IncobotulinumtoxinA Injection

    Science.gov (United States)

    ... injection is used to relieve the symptoms of cervical dystonia (spasmodic torticollis; uncontrollable tightening of the neck ... is injected into a muscle, it blocks the nerve signals that cause uncontrollable tightening and movements of ...

  17. RimabotulinumtoxinB Injection

    Science.gov (United States)

    (rim a bott' you lye num bee)RimabotulinumtoxinB injection may spread from the area of injection and ... Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

  18. Sodium Ferric Gluconate Injection

    Science.gov (United States)

    Sodium ferric gluconate injection is used to treat iron-deficiency anemia (a lower than normal number of ... are also receiving the medication epoetin (Epogen, Procrit). Sodium ferric gluconate injection is in a class of ...

  19. Zoledronic Acid Injection

    Science.gov (United States)

    ... experience a reaction during the first few days after you receive a dose of zoledronic acid injection. Symptoms ... symptoms may begin during the first 3 days after you receive a dose of zoledronic acid injection and ...

  20. Urinary incontinence - injectable implant

    Science.gov (United States)

    Injectable implants are injections of material into the urethra to help control urine leakage ( urinary incontinence ) caused by a ... into the tissue next to the sphincter. The implant procedure is usually done in the hospital. Or ...

  1. The kicker magnet system for TRISTAN Accumulation Ring injection

    International Nuclear Information System (INIS)

    The injection of electron beams to TRISTAN Accumulation Ring (AR) was started in November 1983 and the positron injection started in November 1985. For the injection of electron and positron beams to AR, the unique kicker system was developed. In the kicker power supply the charging to the main capacitor was done with the resonant charge system together with the auxiliary charging unit. The impedance matching circuit was added to the kicker magnet for getting the required current form with least reflecting oscillation. In this paper we report the performance of this kicker system. (author)

  2. Nanostructuring steel for injection molding tools

    International Nuclear Information System (INIS)

    The production of nanostructured plastic items by injection molding with ridges down to 400 nm in width, which is the smallest line width replicated from nanostructured steel shims, is presented. Here we detail a micro-fabrication method where electron beam lithography, nano-imprint lithography and ion beam etching are combined to nanostructure the planar surface of a steel wafer. Injection molded plastic parts with enhanced surface properties, like anti-reflective, superhydrophobic and structural colors can be achieved by micro- and nanostructuring the surface of the steel molds. We investigate the minimum line width that can be realized by our fabrication method and the influence of etching angle on the structure profile during the ion beam etching process. Trenches down to 400 nm in width have been successfully fabricated into a 316 type electro-polished steel wafer. Afterward a plastic replica has been produced by injection molding with good structure transfer fidelity. Thus we have demonstrated that by utilizing well-established fabrication techniques, nanostructured steel shims that are used in injection molding, a technique that allows low cost mass fabrication of plastic items, are produced. (paper)

  3. Transmission of the Neutral Beam Heating Beams at TJ-II

    International Nuclear Information System (INIS)

    Neutral beam injection heating has been development for the TJ-II stellarator. The beam has a port-through power between 700-1500 kW and injection energy 40 keV. The sensibility of the injection system to the changes of several parameters is analysed. Beam transmission is limited by losses processes since beam is born into the ions source until is coming into the fusion machine. For the beam transmission optimization several beam diagnostics have been developed. A carbon fiber composite (CFC) target calorimeter has been installed at TJ-II to study in situ the power density distribution of the neutral beams. The thermographic print of the beam can be recorded and analysed in a reliable way due to the highly anisotropic thermal conductivity of the target material. With the combined thermographic and calorimetric measurements it has been possible to determine the power density distribution of the beam. It has been found that a large beam halo is present, which can be explained by the extreme misalignment of the grids. This kind of halo has a deleterious effect on beam transport and must be minimized in order to improve the plasma heating capability of the beams. (Author) 155 refs

  4. Simulation of intense beam bunching using 3D PIC method

    International Nuclear Information System (INIS)

    Most of the ion sources produce continuous beam of charged particles. In a cyclotron using such an external ion source, only a small fraction of the injected continuous beam is accepted in the central region for further acceleration. By transforming the continuous beam into a suitably bunched beam using a buncher prior to injection, the amount of accepted particles in the central region of cyclotron can be increased. To compress the continuous beam longitudinally one needs to impose a velocity modulation at the buncher gap which results in density modulation as the beam advances. In the case of low beam current the velocity modulation of the beam has very little effect on the transverse envelope of the beam. However, in the case of high intensity beams, the space-charge force introduces much collective behaviour and increase of current in the specified bunch width affects the transverse dynamics

  5. PEP-II injection timing and controls

    Energy Technology Data Exchange (ETDEWEB)

    Bharadwaj, V.; Browne, M.; Crane, M.; Gromme, T.; Himel, T.; Ross, M.; Stanek, M. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Ronan, M. [Lawrence Berkeley National Lab., CA (United States)

    1997-07-01

    Hardware has been built and software written and incorporated in the existing SLC accelerator control system to control injection of beam pulses from the accelerator into the PEP-II storage rings currently under construction. Hardware includes a CAMAC module to delay the machine timing fiducial in order that a beam pulse extracted from a damping ring will be injected into a selected group of four 476 MHz buckets in a PEP-II ring. Further timing control is accomplished by shifting the phase of the bunches stored in the damping rings before extraction while leaving the phase of the PEP-II stored beam unchanged. The software which drives timing devices on a pulse-to-pulse basis relies on a dedicated communication link on which one scheduling microprocessor broadcasts a 128-bit message to all distributed control microprocessors at 360 Hz. PEP-II injection will be driven by the scheduling microprocessor according to lists specifying bucket numbers in arbitrary order, and according to scheduling constraints maximizing the useful beam delivered to the SLC collider currently in operation. These lists will be generated by a microprocessor monitoring the current stored per bucket in each of the PEP-II rings.

  6. A Logic of Injectivity

    CERN Document Server

    Adamek, J; Souza, L

    2007-01-01

    Injectivity of objects with respect to a set $\\ch$ of morphisms is an important concept of algebra, model theory and homotopy theory. Here we study the logic of injectivity consequences of $\\ch$, by which we understand morphisms $h$ such that injectivity with respect to $\\ch$ implies injectivity with respect to $h$. We formulate three simple deduction rules for the injectivity logic and for its finitary version where \\mor s between finitely ranked objects are considered only, and prove that they are sound in all categories, and complete in all "reasonable" categories.

  7. Laser-Assisted H- Charge Exchange Injection in Magnetic Fields

    Energy Technology Data Exchange (ETDEWEB)

    Gorlov, Timofey V [ORNL; Danilov, Viatcheslav V [ORNL; Shishlo, Andrei P [ORNL

    2010-01-01

    The use of stripping foils for charge exchange injection can cause a number of operational problems in high intensity hadron accelerators. A recently proposed three-step method of laser-assisted injection is capable of overcoming these problems. This paper presents advances in the physical model of laser-assisted charge exchange injection of H- beams and covers a wide field of atomic physics. The model allows the calculation of the evolution of an H0 beam taking into account spontaneous emission, field ionization and external electromagnetic fields. Some new data on the hydrogen atom related to the problem are calculated. The numerical calculations in the model use realistic descriptions of laser field and injection beam. Generally, the model can be used for design and optimization of a laser-assisted injection cell within an accelerator lattice. Example calculations of laser-assisted injection for an intermediate experiment at SNS in Oak Ridge and for the PS2 accelerator at CERN are presented. Two different schemes, distinctively characterized by various magnetic fields at the excitation point, are discussed. It was shown that the emittance growth of an injected beam can be drastically decreased by moving excitation point into a strong magnetic field.

  8. Laser-assisted H- charge exchange injection in magnetic fields

    Science.gov (United States)

    Gorlov, T.; Danilov, V.; Shishlo, A.

    2010-05-01

    The use of stripping foils for charge exchange injection can cause a number of operational problems in high intensity hadron accelerators. A recently proposed three-step method of laser-assisted injection is capable of overcoming these problems. This paper presents advances in the physical model of laser-assisted charge exchange injection of H- beams and covers a wide field of atomic physics. The model allows the calculation of the evolution of an H0 beam taking into account spontaneous emission, field ionization, and external electromagnetic fields. Some new data on the hydrogen atom related to the problem are calculated. The numerical calculations in the model use realistic descriptions of laser field and injection beam. Generally, the model can be used for design and optimization of a laser-assisted injection cell within an accelerator lattice. Example calculations of laser-assisted injection for an intermediate experiment at SNS in Oak Ridge and for the PS2 accelerator at CERN are presented. Two different schemes, distinctively characterized by various magnetic fields at the excitation point, are discussed. It was shown that the emittance growth of an injected beam can be drastically decreased by moving the excitation point into a strong magnetic field.

  9. Beam simulation studies of ECR beam extraction and low energy beam transport for FRIB

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Haitao, E-mail: ren@frib.msu.edu; Pozdeyev, Eduard; Lund, Steven M.; Machicoane, Guillaume; Wu, Xiaoyu; Morgan, Glenn [Facility for Rare Isotope Beams, Michigan State University, East Lansing, Michigan 48824 (United States)

    2016-02-15

    To meet the beam power requirements of 400 kW at the fragmentation target for facility for Rare Isotope Beams (FRIB), simultaneous acceleration of two-charge states should be used for heavier ions. These intense multi-charged ion beams will be produced by a 28 GHz electron cyclotron resonance (ECR) ion source at a high voltage of 35 kV. After extraction, the ion beam will be pre-accelerated to 12 keV/u with a 50 kV platform, transported down to an achromatic charge state selection (CSS) system followed by a vertical transport line, and then injected into a radio frequency quadrupole accelerator. The TRACK code developed at ANL is used to perform the simulations of the ECR beam extraction and low energy beam transport for FRIB. In this study, we include the magnetic field of ECR ion source into simulations. Different initial beam conditions as well as different space charge neutralization levels are tested for the ECR beamline. The beam loss in CSS system and the corresponding protective measures are discussed. The detailed results about the beam dynamic simulation and beam loss in CSS system will be presented in this paper.

  10. Beam simulation studies of ECR beam extraction and low energy beam transport for FRIB

    Science.gov (United States)

    Ren, Haitao; Pozdeyev, Eduard; Lund, Steven M.; Machicoane, Guillaume; Wu, Xiaoyu; Morgan, Glenn

    2016-02-01

    To meet the beam power requirements of 400 kW at the fragmentation target for facility for Rare Isotope Beams (FRIB), simultaneous acceleration of two-charge states should be used for heavier ions. These intense multi-charged ion beams will be produced by a 28 GHz electron cyclotron resonance (ECR) ion source at a high voltage of 35 kV. After extraction, the ion beam will be pre-accelerated to 12 keV/u with a 50 kV platform, transported down to an achromatic charge state selection (CSS) system followed by a vertical transport line, and then injected into a radio frequency quadrupole accelerator. The TRACK code developed at ANL is used to perform the simulations of the ECR beam extraction and low energy beam transport for FRIB. In this study, we include the magnetic field of ECR ion source into simulations. Different initial beam conditions as well as different space charge neutralization levels are tested for the ECR beamline. The beam loss in CSS system and the corresponding protective measures are discussed. The detailed results about the beam dynamic simulation and beam loss in CSS system will be presented in this paper.

  11. Beam simulation studies of ECR beam extraction and low energy beam transport for FRIB

    International Nuclear Information System (INIS)

    To meet the beam power requirements of 400 kW at the fragmentation target for facility for Rare Isotope Beams (FRIB), simultaneous acceleration of two-charge states should be used for heavier ions. These intense multi-charged ion beams will be produced by a 28 GHz electron cyclotron resonance (ECR) ion source at a high voltage of 35 kV. After extraction, the ion beam will be pre-accelerated to 12 keV/u with a 50 kV platform, transported down to an achromatic charge state selection (CSS) system followed by a vertical transport line, and then injected into a radio frequency quadrupole accelerator. The TRACK code developed at ANL is used to perform the simulations of the ECR beam extraction and low energy beam transport for FRIB. In this study, we include the magnetic field of ECR ion source into simulations. Different initial beam conditions as well as different space charge neutralization levels are tested for the ECR beamline. The beam loss in CSS system and the corresponding protective measures are discussed. The detailed results about the beam dynamic simulation and beam loss in CSS system will be presented in this paper

  12. Neutral beam data systems at ORNL

    International Nuclear Information System (INIS)

    A control system for neutral injection beam lines has been designed, implemented, and used with much success. Despite the problems with very high power levels this system is very successful in relieving the operators burdens of slow conditioning, data recording, and mode switching. The use of computer control with multiple beam lines now appears very promising

  13. BATMAN beam properties characterization by the beam emission spectroscopy diagnostic

    International Nuclear Information System (INIS)

    The ITER neutral beam heating systems are based on the production and acceleration of negative ions (H/D) up to 1 MV. The requirements for the beam properties are strict: a low core beam divergence (< 0.4 °) together with a low source pressure (≤ 0.3 Pa) would permit to reduce the ion losses along the beamline, keeping the stripping particle losses below 30%. However, the attainment of such beam properties is not straightforward. At IPP, the negative ion source testbed BATMAN (BAvarian Test MAchine for Negative ions) allows for deepening the knowledge of the determination of the beam properties. One of the diagnostics routinely used to this purpose is the Beam Emission Spectroscopy (BES): the Hα light emitted in the beam is detected and the corresponding spectra are evaluated to estimate the beam divergence and the stripping losses. The BES number of lines of sight in BATMAN has been recently increased: five horizontal lines of sight providing a vertical profile of the beam permit to characterize the negative ion beam properties in relation to the source parameters. Different methods of Hα spectra analysis are here taken into account and compared for the estimation of the beam divergence and the amount of stripping. In particular, to thoroughly study the effect of the space charge compensation on the beam divergence, an additional hydrogen injection line has been added in the tank, which allows for setting different background pressure values (one order of magnitude, from about 0.04 Pa up to the source pressure) in the beam drift region

  14. BATMAN beam properties characterization by the beam emission spectroscopy diagnostic

    Energy Technology Data Exchange (ETDEWEB)

    Bonomo, F., E-mail: federica.bonomo@igi.cnr.it [Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), Corso Stati Uniti 4, 35127 Padova (Italy); Istituto Gas Ionizzati - CNR, Corso Stati Uniti 4, 35127 Padova (Italy); Ruf, B.; Schiesko, L.; Fantz, U.; Franzen, P.; Riedl, R.; Wünderlich, D. [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany); Barbisan, M.; Pasqualotto, R.; Serianni, G. [Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), Corso Stati Uniti 4, 35127 Padova (Italy); Cristofaro, S. [Universitá degli Studi di Padova, Via 8 Febbraio 2, 35122 Padova (Italy)

    2015-04-08

    The ITER neutral beam heating systems are based on the production and acceleration of negative ions (H/D) up to 1 MV. The requirements for the beam properties are strict: a low core beam divergence (< 0.4 °) together with a low source pressure (≤ 0.3 Pa) would permit to reduce the ion losses along the beamline, keeping the stripping particle losses below 30%. However, the attainment of such beam properties is not straightforward. At IPP, the negative ion source testbed BATMAN (BAvarian Test MAchine for Negative ions) allows for deepening the knowledge of the determination of the beam properties. One of the diagnostics routinely used to this purpose is the Beam Emission Spectroscopy (BES): the H{sub α} light emitted in the beam is detected and the corresponding spectra are evaluated to estimate the beam divergence and the stripping losses. The BES number of lines of sight in BATMAN has been recently increased: five horizontal lines of sight providing a vertical profile of the beam permit to characterize the negative ion beam properties in relation to the source parameters. Different methods of H{sub α} spectra analysis are here taken into account and compared for the estimation of the beam divergence and the amount of stripping. In particular, to thoroughly study the effect of the space charge compensation on the beam divergence, an additional hydrogen injection line has been added in the tank, which allows for setting different background pressure values (one order of magnitude, from about 0.04 Pa up to the source pressure) in the beam drift region.

  15. Electron beam emission and interaction of double-beam gyrotron

    International Nuclear Information System (INIS)

    Highlights: ► The complete electrical design of electron gun and interaction structure of double-beam gyrotron. ► EGUN code is used for the simulation of electron gun of double-beam gyrotron. ► MAGIC code is used for the simulation of interaction structure of double-beam gyrotron. ► Design validations with other codes. - Abstract: This paper presents the numerical simulation of a double-beam magnetron injection gun (DB-MIG) and beam-wave interaction for 60 GHz, 500 kW gyrotron. The beam-wave interaction calculations, power and frequency growth estimation are performed by using PIC code MAGIC. The maximum output power of 510 kW at 41.5% efficiency, beam currents of 6 A and 12 A, electron beam velocity ratios of 1.41 and 1.25 and beam voltage of 69 kV are estimated. To obtain the design parameters, the DB-MIG with maximum transverse velocity spread less than 5% is designed. The computer simulations are performed by using the commercially available code EGUN and the in-house developed code MIGANS. The simulated results of DB-MIG design obtained by using the EGUN code are also validated with another trajectory code TRAK, which are in good agreement.

  16. ICFA Beam Dynamics Newsletter

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Zvi I.; Kuczewski A.; Altinbas, Z.; Beavis, D.; Belomestnykh,; Dai, J. et al

    2012-07-01

    The Collider-Accelerator Department at Brookhaven National Laboratory is building a high-brightness 500 mA capable Energy Recovery Linac (ERL) as one of its main R&D thrusts towards eRHIC, the polarized electron - hadron collider as an upgrade of the operating RHIC facility. The ERL is in final assembly stages, with injection commisioning starting in October 2012. The objective of this ERL is to serve as a platform for R&D into high current ERL, in particular issues of halo generation and control, Higher-Order Mode (HOM) issues, coherent emissions for the beam and high-brightness, high-power beam generation and preservation. The R&D ERL features a superconducting laser-photocathode RF gun with a high quantum efficiency photoccathode served with a load-lock cathode delivery system, a highly damped 5-cell accelerating cavity, a highly flexible single-pass loop and a comprehensive system of beam instrumentation. In this ICFA Beam Dynamics Newsletter article we will describe the ERL in a degree of detail that is not usually found in regular publications. We will discuss the various systems of the ERL, following the electrons from the photocathode to the beam dump, cover the control system, machine protection etc and summarize with the status of the ERL systems.

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

    Science.gov (United States)

    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.

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

    CERN Document Server

    Corde, S; Lifschitz, A; Lambert, G; Phuoc, K Ta; 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 centimeter 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.

  19. MD on Injection Quality – Longitudinal and Transverse Parameters

    CERN Document Server

    Drosdal, L; Bohl, T; Bracco, C; Cornelis, K; Damerau, H; Goddard, B; Kain, V; Meddahi, M

    2011-01-01

    Losses at injection depend on the beam quality in the longitudinal and transverse plane in the injectors. During the MD on the 30th of June to 1st of July, 2011, many parameters in the injectors were de-tuned on purpose to see the effect on injection losses and hence bring some understanding to recurring problems with injection quality during LHC filling. The effect of the 800 MHz in the SPS, radial steering, larger momentum spread at the SPS extraction and many other longitudinal parameters were studied during the MD. The MD showed however that the injection losses are dominated by far by the transverse size of the particle population. If the SPS scrapers are correctly positioned, injection losses are low even at the presence of quality issues in the longitudinal plane. To be able to inject brighter 50 ns beams or eventually 25 ns beams, injection losses with nominal emittances (3.5 m) must still be acceptable. This MD showed that nominal emittances can be injected with similar loss levels as the typical ...

  20. Magnetic configuration effects on plasma transport under Neutral Beam Injection at TJ-II (Simulation); Efectos de Configuracion Magnetica en el Transporte de Plasma durante la Inyeccion de Haces Neutros en el TJ-II (Simulacion)

    Energy Technology Data Exchange (ETDEWEB)

    Guasp, J.; Fuentes, C.; Liniers, M.

    2001-07-01

    A systematic analysis of magnetic configurations (27 in total), using a Transport model including impurity dynamics and sputtering effects has been done. For small size configurations or those close to rational t values there is radioactive collapse, independently of the external gas puffing (GP) strategy chosen. The reason is the insufficiency of observed power, either by the high shine through losses due to their low radii, or by the increase of fast ion orbit losses near the resonances. For the majority of configurations without collapse, fast ion orbit losses for CO injection (going in the same direction than the toroidal magnetic field) are higher, and in consequence the power absorption and the plasma {beta} achieved are laser, than for the opposite direction. Nevertheless in the region placed just above the main resonances (1/3 and 1/2 per period) this situation reverses. The reasons have been analysed and explained at previous studies. A consequence of this fact is that the optima of confinement for the Counter case are shifted towards higher t values than the CO one, with higher plasma {beta}, except near the resonances. As usual the balanced case is in between. The optima achieving stationary state are very close (and often are coincident) with those lacking that restriction. The best configuration (highest average {beta}) for balanced injection, with <{beta}>=1.1% and central value 3.2%, although in this region the results are rather insensitive to configuration and GP strategy. The configurations placed around the 100{sub 4}4 would need also the lowest power entering the torus in order to avoid collapse and to achieve an acceptable NBI absorption level. (Author) 12 refs.

  1. Optimized bunching in the spiral inflector of the CYCLONE 44 injection system

    International Nuclear Information System (INIS)

    The University at Louvain-la-Neuve is building a compact cyclotron as a post-accelerator/separator for radioactive ion beams called CYCLONE-44. To achieve a high overall injection efficiency it is necessary to ensure proper 6D beam matching of the injected beam to the cyclotron central region. The key component in the cyclotron injection system is a spiral inflector that will place the beam at correct position in the median plane. This paper deals with the optimized beam bunching in the inflector. Using transfer matrix techniques the conditions for obtaining minimized bunch lengths at the inflector exit were derived. Consistent will some previous publications, the time spread of the beam at the inflector exit for the large injected emittances required in this applications is significant. It will be shown that these large pulse lengths are a direct consequence of the inflector optics. (authors)

  2. Los Alamos Proton Storage Ring (PSR) injection deflector system

    International Nuclear Information System (INIS)

    We describe a pulsed magnetic deflector system planned for the injection system of the PSR. Two sets of magnets, appropriately placed in the optical systems of both the ring and the injection transport line, provide control of the rate at which particles are injected into a given portion of transverse phase space and limit the interaction of stored beam with the injection stripping foil. High-current modulators that produce relatively complex waveforms are required for this purpose. Solid-state drivers using direct feedback to produce the necessary waveforms are discussed as replacements for the more conventional high-voltage tube technology

  3. Epidural injections for back pain

    Science.gov (United States)

    ESI; Spinal injection for back pain; Back pain injection; Steroid injection - epidural; Steroid injection - back ... pillow under your stomach. If this position causes pain, you either sit up or lie on your ...

  4. Beam - cavity interaction beam loading

    International Nuclear Information System (INIS)

    The interaction of a beam with a cavity and a generator in cyclic accelerators or storage rings is investigated. Application of Maxwell's equations together with the nonuniform boundary condition allows one to get an equivalent circuit for a beam-loaded cavity. The general equation for beam loading is obtained on the basis of the equivalent circuit, and the beam admittance is calculated. Formulas for power consumption by a beam-loaded cavity are derived, and the optimal tuning and coupling factor are analyzed. (author)

  5. Sciatic nerve injection injury.

    Science.gov (United States)

    Jung Kim, Hyun; Hyun Park, Sang

    2014-06-11

    Nerve injury is a common complication following intramuscular injection and the sciatic nerve is the most frequently affected nerve, especially in children, the elderly and underweight patients. The neurological presentation may range from minor transient pain to severe sensory disturbance and motor loss with poor recovery. Management of nerve injection injury includes drug treatment of pain, physiotherapy, use of assistive devices and surgical exploration. Early recognition of nerve injection injury and appropriate management are crucial in order to reduce neurological deficit and to maximize recovery. Sciatic nerve injection injury is a preventable event. Total avoidance of intramuscular injection is recommended if other administration routes can be used. If the injection has to be administered into the gluteal muscle, the ventrogluteal region (gluteal triangle) has a more favourable safety profile than the dorsogluteal region (the upper outer quadrant of the buttock). PMID:24920643

  6. Calculation of the system for ion axial injection into the U-200 isochronous cyclotron

    International Nuclear Information System (INIS)

    An axial injection system is calculated for injection of ion beams (A/Z=2.8-5) into the U-200 isochronous cyclotron, its basic performance characteristics are discussed. Transport channel consisting of solenoids, magnetic lenses and electrostatic mirror are calculated by TRANSPORT program. Acceptance of the system is in good agreement with the beam emittance of 313π mmxmrad. Numerical optimization of mirror parameters is presented. The calculated beam envelope in the central region agrees well the measurements

  7. Beam Instrumentation of the PXIE LEBT Beamline

    Energy Technology Data Exchange (ETDEWEB)

    D' Arcy, R. [Fermilab; Hanna, B. [Fermilab; Prost, L. [Fermilab; Scarpine, v. [Fermilab; Shemyakin, A. [Fermilab

    2015-06-01

    The PXIE accelerator [1] is the front-end test stand of the proposed Proton Improvement Plan (PIP-II) [2] initiative: a CW-compatible pulsed H- superconducting RF linac upgrade to Fermilab’s injection system. The PXIE Ion Source and Low-Energy Beam Transport (LEBT) section are designed to create and transfer a 1-10 mA $H^{-}$ beam, in either pulsed (0.001–16 ms) or DC mode, from the ion source through to the injection point of the RFQ. This paper discusses the range of diagnostic tools – Allison-type Emittance Scanner, Faraday Cup, Toroid, DCCT, electrically isolated diaphragms – involved in the commissioning of the beam line and preparation of the beam for injection into the RFQ.

  8. Urinary incontinence - injectable implant

    Science.gov (United States)

    ... repair; ISD repair; Injectable bulking agents for stress urinary incontinence ... Blaivas JM, Gormley EA, et al. Female Stress Urinary Incontinence Update Panel of the American Urological Association Education ...

  9. Injection moulding antireflective nanostructures

    DEFF Research Database (Denmark)

    Christiansen, Alexander Bruun; Clausen, Jeppe Sandvik; Mortensen, N. Asger;

    2014-01-01

    We present a method for injection moulding antireflective nanostructures on large areas, for high volume production. Nanostructured black silicon masters were fabricated by mask-less reactive ion etching, and electroplated with nickel. The nickel shim was antistiction coated and used in an...... injection moulding process, to fabricate the antireflective surfaces. The cycle-time was 35 s. The injection moulded structures had a height of 125 nm, and the visible spectrum reflectance of injection moulded black polypropylene surfaces was reduced from 4.5±0.5% to 2.5±0.5%. The gradient of the refractive...

  10. Injection moulding antireflective nanostructures

    DEFF Research Database (Denmark)

    Christiansen, Alexander Bruun; Clausen, Jeppe Sandvik; Mortensen, N. Asger;

    We present a method for injection moulding antireflective nanostructures on large areas, for high volume production. Nanostructured black silicon masters were fabricated by mask-less reactive ion etching, and electroplated with nickel. The nickel shim was antistiction coated and used in an...... injection moulding process, to fabricate the antireflective surfaces. The cycle-time was 35 s. The injection moulded structures had a height of 125 nm, and the visible spectrum reflectance of injection moulded black polypropylene surfaces was reduced from 4.5±0.5% to 2.5±0.5%. The gradient of the refractive...

  11. Frozen Beams

    CERN Document Server

    Okamoto, Hiromi

    2005-01-01

    In general, the temperature of a charged particle beam traveling in an accelerator is very high. Seen from the rest frame of the beam, individual particles randomly oscillate about the reference orbit at high speed. This internal kinetic energy can, however, be removed by introducing dissipative interactions into the system. As a dissipative process advances, the beam becomes denser in phase space or, in other words, the emittance is more diminished. Ideally, it is possible to reach a "zero-emittance" state where the beam is Coulomb crystallized. The space-charge repulsion of a crystalline beam just balances the external restoring force provided by artificial electromagnetic elements. In this talk, general discussion is made of coasting and bunched crystalline beams circulating in a storage ring. Results of molecular dynamics simulations are presented to demonstrate the dynamic nature of various crystalline states. A possible method to approach such an ultimate state of matter is also discussed.

  12. Injection schemes for the TOP Linac

    International Nuclear Information System (INIS)

    In this report two schemes are studied for the injection in the SCDTL section of the TOP Linac of the proton beam produced by a 7 MeV linear accelerator. The project derives by an agreement between ENEA (National Agency for New Technology, Energy and Environment) and ISS. In these new versions of the design the constraint of a synchronization of the radio frequencies of the two accelerators is suppressed

  13. Semiconductor Laser With Two-Dimensional Beam Steering

    Science.gov (United States)

    Katz, J.

    1986-01-01

    Modification of monolithic semiconductor injection laser capable of one-dimensional electronic beam steering enables deflection of beam in second direction. Such laser chip provides beam pointing or raster scanning for applications in optical communications, data processing, image scanning, and optical ranging.

  14. A new luminescence beam profile monitor for intense proton and heavy ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Tsang,T.; Bellavia, S.; Connolly, R.; Gassner, D.; Makdisi, Y.; Russo, T.; Thieberger, P.; Trbojevic, D.; Zelenski, A.

    2008-10-01

    A new luminescence beam profile monitor is realized in the polarized hydrogen gas jet target at the Relativistic Heavy Ion Collider (RHIC) facility. In addition to the spin polarization of the proton beam being routinely measured by the hydrogen gas jet, the luminescence produced by beam-hydrogen excitation leads to a strong Balmer series lines emission. A selected hydrogen Balmer line is spectrally filtered and imaged to produce the transverse RHIC proton beam shape with unprecedented details on the RHIC beam profile. Alternatively, when the passage of the high energy RHIC gold ion beam excited only the residual gas molecules in the beam path, sufficient ion beam induced luminescence is produced and the transverse gold ion beam profile is obtained. The measured transverse beam sizes and the calculated emittances provide an independent confirmation of the RHIC beam characteristics and to verify the emittance conservation along the RHIC accelerator. This optical beam diagnostic technique by making use of the beam induced fluorescence from injected or residual gas offers a truly noninvasive particle beam characterization, and provides a visual observation of proton and heavy ion beams. Combined with a longitudinal bunch measurement system, a 3-dimensional spatial particle beam profile can be reconstructed tomographically.

  15. Beam loading

    CERN Document Server

    Gamp, Alexander

    2013-01-01

    We begin by giving a description of the radio-frequency generator-cavity-beam coupled system in terms of basic quantities. Taking beam loading and cavity detuning into account, expressions for the cavity impedance as seen by the generator and as seen by the beam are derived. Subsequently methods of beam-loading compensation by cavity detuning, radio-frequency feedback and feedforward are described. Examples of digital radio-frequency phase and amplitude control for the special case of superconducting cavities are also given. Finally, a dedicated phase loop for damping synchrotron oscillations is discussed.

  16. The Injection Laser System on the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Bowers, M; Burkhart, S; Cohen, S; Erbert, G; Heebner, J; Hermann, M; Jedlovec, D

    2006-12-13

    The National Ignition Facility (NIF) is currently the largest and most energetic laser system in the world. The main amplifiers are driven by the Injection Laser System comprised of the master oscillators, optical preamplifiers, temporal pulse shaping and spatial beam formatting elements and injection diagnostics. Starting with two fiber oscillators separated by up to a few angstroms, the pulse is phase modulated to suppress SBS and enhance spatial smoothing, amplified, split into 48 individual fibers, and then temporally shaped by an arbitrary waveform generator. Residual amplitude modulation induced in the preamplifiers from the phase modulation is also precompensated in the fiber portion of the system before it is injected into the 48 pre-amplifier modules (PAMs). Each of the PAMs amplifies the light from the 1 nJ fiber injection up to the multi-joule level in two stages. Between the two stages the pre-pulse is suppressed by 60 dB and the beam is spatially formatted to a square aperture with precompensation for the nonuniform gain profile of the main laser. The input sensor package is used to align the output of each PAM to the main laser and acquire energy, power, and spatial profiles for all shots. The beam transport sections split the beam from each PAM into four main laser beams (with optical isolation) forming the 192 beams of the NIF. Optical, electrical, and mechanical design considerations for long term reliability and availability will be discussed.

  17. Effects of horizontal injection angle displacements on energy measurements with parallel plate energy analyzer

    International Nuclear Information System (INIS)

    A formula including correction due to change of beam injection angle is derived for measurements of beam energy using parallel plate energy analyzers. The formula is mainly aimed for potential measurements in high temperature plasma with heavy ion beam probes. (author)

  18. A study on the steady-state solutions of a Bursian diode in the presence of transverse magnetic field, when the electrons of the injected beam are turned back partially or totally

    Energy Technology Data Exchange (ETDEWEB)

    Pramanik, Sourav; Chakrabarti, Nikhil [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064 (India); Kuznetsov, V. I. [Ioffe Institute, 194021 St. Petersburg (Russian Federation)

    2015-11-15

    The properties of a steady-state planar vacuum diode driven by a cold electron beam have been investigated in the presence of an external transverse magnetic field, employing both the Eulerian and the Lagrangian formalism. With the help of a numerical scheme, the features of the steady-state solutions have been explored in the Eulerian frame, particularly for the case that corresponds to the potential distributions with a virtual cathode. However, exact analytical formulae for the potential and velocity profiles within the inter-electrode region have been derived with the Lagrangian description. In contrast to the previous work [Phys. Plasmas 22, 042110 (2015)], here we have emphasized the situation when electrons are reflected back to the emitter by the magnetic field. Both partial and complete reflection of the electrons due to the magnetic field have been taken into account. Using the emitter electric field as a characteristic parameter, steady-state solutions have been evaluated for specific values of diode length, applied voltage, and magnetic field strength. It has been shown that, due to the inclusion of the magnetic field, a new region of non-unique solutions appears. An external magnetic field seems to have a profound effect in controlling fast electronic switches based on the Bursian diode.

  19. Perceptions of injections

    International Nuclear Information System (INIS)

    Based on interviews with experts in the petroleum and natural gas exploration industry and results of a workshop insight is given into the attitudes, opinions and perceptions on the possibility to store wastes from the exploration activities in the deep underground, e.g. by means of injection. In a separate report a comparison is made on injection and other waste processing options

  20. Injection of Deuterium Pellets

    DEFF Research Database (Denmark)

    Sørensen, H.; Andersen, P.; Andersen, S. A.; Andersen, Verner; Nielsen, Arne Nordskov; Sass, Bjarne Ove; Weisberg, Knud-Vilhelm

    1984-01-01

    A pellet injection system made for the TFR tokamak at Fontenay-aux-Roses, Paris is described. 0.12-mg pellets are injected with velocities of around 600-700 m/s through a 5-m long guide tube. Some details of a new light gas gun are given; with this gun, hydrogen pellets are accelerated to velocit...

  1. Separably injective Banach spaces

    CERN Document Server

    Avilés, Antonio; Castillo, Jesús M F; González, Manuel; Moreno, Yolanda

    2016-01-01

    This monograph contains a detailed exposition of the up-to-date theory of separably injective spaces: new and old results are put into perspective with concrete examples (such as l∞/c0 and C(K) spaces, where K is a finite height compact space or an F-space, ultrapowers of L∞ spaces and spaces of universal disposition). It is no exaggeration to say that the theory of separably injective Banach spaces is strikingly different from that of injective spaces. For instance, separably injective Banach spaces are not necessarily isometric to, or complemented subspaces of, spaces of continuous functions on a compact space. Moreover, in contrast to the scarcity of examples and general results concerning injective spaces, we know of many different types of separably injective spaces and there is a rich theory around them. The monograph is completed with a preparatory chapter on injective spaces, a chapter on higher cardinal versions of separable injectivity and a lively discussion of open problems and further lines o...

  2. Spin injection into semiconductors

    Science.gov (United States)

    Oestreich, M.; Hübner, J.; Hägele, D.; Klar, P. J.; Heimbrodt, W.; Rühle, W. W.; Ashenford, D. E.; Lunn, B.

    1999-03-01

    The injection of spin-polarized electrons is presently one of the major challenges in semiconductor spin electronics. We propose and demonstrate a most efficient spin injection using diluted magnetic semiconductors as spin aligners. Time-resolved photoluminescence with a Cd0.98Mn0.02Te/CdTe structure proves the feasibility of the spin-alignment mechanism.

  3. LHC Report: Beam on

    CERN Multimedia

    Rossano Giachino for the LHC Team

    2012-01-01

    The powering tests described in the last edition of the Bulletin were successfully finished at the end of the first week of March opening the way for 4 TeV operations this year. The beam was back in the machine on Wednesday 14 March. The first collisions at 4 TeV are scheduled for the first week of April.   The first beam of 2012 is dumped after making a few rounds in the LHC. The magnet powering tests were followed by the machine checkout phase. Here the operations team in collaboration with the equipment groups performs a sequence of tests to ensure the readiness of the LHC for beam. The tests include driving all the LHC systems – beam dump, injection, collimation, RF, power converters, magnet circuits, vacuum, interlocks, controls, timing and synchronization – through the operational cycle. The “checkout phase” is really a massive de-bugging exercise, which is performed with the objective of ensuring the proper functioning of the whole machine and t...

  4. Beam position measurements of Indus-2 using X-Ray beam position monitor

    International Nuclear Information System (INIS)

    A staggered pair metal blade X-ray beam position monitor (XBPM) is designed, fabricated and commissioned on Indus-2 bending magnet front end. Calibration of XBPM is done by scanning the metal blades in the path of synchrotron radiation and by giving controlled electron asymmetric bump. The vertical beam position stability of the source measured during various injections and storages are reported.

  5. Beam dynamics with new booster dipoles

    International Nuclear Information System (INIS)

    New bending magnets are being designed for the booster synchrotron at RRCAT, Indore with the same effective length and field which will be installed in the existing ring with the same configuration of drifts and quadrupole magnets. Presently sector type dipoles are in use. It is easier to fabricate parallel edge (rectangular type) dipoles but the beam optics gets modified due to edges which provide additional focusing. The effect on tune point can be corrected using two quadrupole families. Studies indicate that the beam emittance is lower in the optics with rectangular type dipoles but the beam injection and extraction are more difficult. In this paper, the beam optics, beam emittance, injection and extraction with two configurations of the dipole magnets are compared. (author)

  6. Intense relativistic electron beam: generation and propagation

    International Nuclear Information System (INIS)

    A general review of relativistic electron beam extracted from explosive field emission diode has been presented here. The beam current in the diode gap taking into account cathode and anode plasma expansion velocity and excluding the self magnetic field effect is directly proportional to gap voltage V3/2 and inversely proportional to the square of the effective diode gap (d-vt). In the limit of high current, self magnetic field focusing effect comes into play and results in a critical current at which pinching will take place. When the diode current exceeds the critical current, the electron flow is in the para-potential regime. Different diode geometries such as planner, coaxial, rod-pinched, reflex triode are discussed qualitatively. When the beam is injected into a vacuum drift tube the propagation of the beam is only possible in presence of a strong axial magnetic field which prevents the beam expansion in the radial direction. If the beam is injected in the drift tube filled with dense plasma, then the redistribution of the plasma electrons effectively neutralizes the beam space charge, resulting subsequent propagation of the beam along the drift tube. The beam propagation through neutral gas is similar to the plasma filled drift tube. In this case both the neutral gas pressure and the beam current regulate the transmission of the REB. (author)

  7. Ion-beam-driven lower-hybrid instability and resultant anomalous beam slowing

    International Nuclear Information System (INIS)

    A lower-hybrid instability with ion cyclotron harmonics is observed to be driven by an ion beam injected obliquely to the magnetic field confining the isothermal plasma of the Q-1 double plasma device. The instability occurs with the injection of a low density, low velocity beam and propagates normal to the field with phase velocity ω/k/sub perpendicular/ approximately equal to u/sub b//sub perpendicular/, the perpendicular velocity component of the spiraling ions. The frequency spectrum, propagation, and growth rate are all in good agreement with a numerical calculation based on linear kinetic theory. Pulsed beams are used to follow the instability from the linearly growing stage to nonlinear saturation. The anomalous perpendicular momentum loss of the beam is examined by both direct energy analysis and by measurements of the resultant beam orbit modifications. By varying the beam parameters, a transition of the nonlinear saturation mechanism from the quasilinear to the trapping regime is demonstrated

  8. Beam Instabilities

    CERN Document Server

    Rumolo, G

    2014-01-01

    When a beam propagates in an accelerator, it interacts with both the external fields and the self-generated electromagnetic fields. If the latter are strong enough, the interplay between them and a perturbation in the beam distribution function can lead to an enhancement of the initial perturbation, resulting in what we call a beam instability. This unstable motion can be controlled with a feedback system, if available, or it grows, causing beam degradation and loss. Beam instabilities in particle accelerators have been studied and analysed in detail since the late 1950s. The subject owes its relevance to the fact that the onset of instabilities usually determines the performance of an accelerator. Understanding and suppressing the underlying sources and mechanisms is therefore the key to overcoming intensity limitations, thereby pushing forward the performance reach of a machine.

  9. Neutral beams for magnetic fusion

    International Nuclear Information System (INIS)

    Significant advances in forming energetic beams of neutral hydrogen and deuterium atoms have led to a breakthrough in magnetic fusion: neutral beams are now heating plasmas to thermonuclear temperatures, here at LLL and at other laboratories. For example, in our 2XIIB experiment we have injected a 500-A-equivalent current of neutral deuterium atoms at an average energy of 18 keV, producing a dense plasma (1014 particles/cm3) at thermonuclear energy (14 keV or 160 million kelvins). Currently, LLL and LBL are developing beam energies in the 80- to 120-keV range for our upcoming MFTF experiment, for the TFTR tokamak experiment at Princeton, and for the Doublet III tokamak experiment at General Atomic. These results increase our long-range prospects of producing high-intensity beams of energies in the hundreds or even thousands of kilo-electron-volts, providing us with optimistic extrapolations for realizing power-producing fusion reactors

  10. Energetic ion diagnostics using neutron flux measurements during pellet injection

    International Nuclear Information System (INIS)

    Neutron measurements during injection of deuterium pellets into deuterium plasmas on the Tokamak Fusion Test Reactor (TFTR) indicate that the fractional increase in neutron emission about 0.5 msec after pellet injection is proportional to the fraction of beam-plasma reactions to total fusion reactions in the unperturbed plasma. These observations suggest three diagnostic applications of neutron measurements during pellet injection: (1) measurement of the beam-plasma reaction rate in deuterium plasmas for use in determining the fusion Q in an equivalent deuterium-tritium plasma, (2) measurement of the radial profile of energetic beam ions by varying the pellet size and velocity, and (3) measurement of the ''temperature'' of ions accelerated during wave heating. 18 refs., 3 figs

  11. Wall conditioning with impurity pellet injection on TFTR

    International Nuclear Information System (INIS)

    Solid lithium and boron pellets have been injected into TFTR plasmas to improve plasma performance by coating the graphite inner wall bumper limiter with a small amount of lower Z pellet material, which reduces the influx of carbon from the walls and reduces the edge electron density. This new wall conditioning technique has been applied successfully when continued He conditioning discharges, which are normally used for wall conditioning, no longer significantly reduce the carbon and deuterium influxes. The results show that both Li and B pellets significantly improve wall conditioning and lead to 15-20% improvements in supershot plasma performance when injected ≥1 s prior to neutral beam injection in supershot target plasmas. Neutral beam penetration calculations indicate that the lower edge densities resulting from Li or B pellet wall conditioning lead to improved beam penetration. Sputtering yield calculations confirm that the addition of small amounts of Li on a graphite target can significantly reduce the C sputtering yield. (orig.)

  12. AA, beam stopper with scintillator screen

    CERN Multimedia

    1980-01-01

    An insertable steel-plate beam stopper was located after nearly a full turn downstream of the injection point. It was fitted with a scintillator screen, a thin plate of Cr-doped alumina, imprinted with a grid and reference points. The screen was illuminated through a window and observed with a highly sensitive TV camera plus image intensifier. This allowed observation of beam position and size of a proton test beam and of the beam from the target, which consisted not only of antiprotons but contained as well electrons, pions and muons of the same momentum.

  13. Injection Protection Upgrade for the HL-LHC

    CERN Document Server

    Uythoven, Jan; Bracco, Chiara; Frasciello, Oscar; Gentini, Luca; Goddard, Brennan; Lechner, Anton; Maciariello, Fausto; Perillo Marcone, Antonio; Salvant, Benoit; Shetty, Nikhil Vittal; Steele, Genevieve; Velotti, Francesco; Zobov, Mikhail

    2015-01-01

    The injector complex of the LHC is undergoing important changes in the light of the LIU project to provide brighter beams to the LHC. For this reason and as part of the High Luminosity LHC project the injection protection system of the LHC will be upgraded in the Long Shutdown 2 (2018 - 2019) to be able to protect downstream elements against injection failures with the high brightness, high intensity HL-LHC beams. The upgraded LHC injection protection system will consist of a segmented injection protection absorber TDIS, and auxiliary collimators and masks. The layout modifications are described, and the machine element protection and absorber jaw robustness studies are presented for the new systems.

  14. Phase Space Dynamics of Ionization Injection in Plasma Based Accelerators

    CERN Document Server

    Xu, X L; 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; Mori, W B; Joshi, C

    2013-01-01

    The evolution of beam phase space in ionization-induced injection into plasma wakefields is studied using theory and particle-in-cell (PIC) simulations. The injection process causes special longitudinal and transverse phase mixing leading initially to a rapid emittance growth followed by oscillation, decay, and eventual slow growth to saturation. An analytic theory for this evolution is presented that includes the effects of injection distance (time), acceleration distance, wakefield structure, and nonlinear space charge forces. Formulas for the emittance in the low and high space charge regimes are presented. The theory is verified through PIC simulations and a good agreement is obtained. This work shows how ultra-low emittance beams can be produced using ionization-induced injection.

  15. Experimental analysis of multi-lambda injection locking in single mode Fabry-Pérot laser diode

    Science.gov (United States)

    Nakarmi, Bikash; Zhang, Xuping; Won, Yong Hyub

    2016-01-01

    In this paper, we propose multi-lambda injection locking in a single mode Fabry-Pérot laser diode and experimentally analyze its effect on various characteristics of Fabry-Pérot laser diode. We consider mode of the injected beam, number of input injected beams, wavelength detuning, and injected power as important parameters in the analysis of suppression of the dominant mode and hysteresis width. The power required for injection locking is proportional to wavelength detuning, which is one of the important parameters for implementing latching device, switching device, and various other optical devices using single mode Fabry-Pérot laser diode. In multi-lambda injection locking, the amount of power required for the injected beam with and without suppression of self-injected mode plays an important role, and hence, is taken into account in our experiment. The spectrum domain output of three- and four-input NAND gate is shown to verify the concept of multi-lambda injection locking. We observe ON/OFF contrast ratio of more than 40 dB when all beams are injection locked, whereas about 1.5 dB ON/OFF contrast ratio in all other combinations of input beam injection. The analysis of multi-lambda injection locking can be used for multi-input optical devices such as multi-input logic gates, latches, and switches.

  16. The first test experiment of H- charge-exchange injection in the KEK booster

    International Nuclear Information System (INIS)

    The H- charge-exchange injection method was applied to the 500 MeV booster of the 12 GeV proton synchrotron at KEK, as an alternative to the multi-turn injection method using direct injection of protons. The first test experiment of such injection was carried out during three weeks beginning in late September 1983. Experimental results showed that, in spite of the low injection energy used for our booster, such an injection method is promising for increasing the beam intensity of the booster. And also, some further improvements are proposed. (author)

  17. Beam Studies Made with the SPS Ionization Profile Monitor

    CERN Document Server

    Ferioli, G; Koopman, J; Roncarolo, F

    2003-01-01

    During the last two years of SPS operation, investigations were pursued on the ability of the SPS ionization profile monitor prototype to fulfill different tasks. It is now established that the instrument can be used for injection matching tuning, by turn to turn recording of the beam size after the injection. Other applications concern beam size measurements on beams ranging from an individual bunch to a nominal SPS batch foreseen for injection into the LHC (288 bunches). By continuously tracking throughout the SPS acceleration cycle from 26 GeV to 450 GeV the evolution of parameters associated to the beam size, it is possible to explain certain beam behaviour. Comparisons are also made at different beam currents and monitor gains with measurements made with the wire scanners. Data are presented and discussed, and the possible implementation of new features is suggested in order to further improve the consistency of the measurements.

  18. Low frequency processing for PSR beam position monitors

    International Nuclear Information System (INIS)

    The beam is injected into the Proton Storage Ring (PSR) as a train of sub-nanosecond pulses at the linac frequency of 201.25 MHz. This frequency component is sensed by 20 pairs of 200 MHz stripline beam position monitors and multiplexed to an autocorrelation position processor. The analog position information is sampled, digitized and stored under the control of timing circuits. Beam position histograms from sets of monitors are displayed in the control room. Measurements show that the amplitude of the 200 MHz component is constant during the fill indicating that the strength of the most recently injected beam does not drift during the fill. This structure begins to disappear 20 to 20 turns after a particular batch of beam has been injected. The low frequency components, however, persist and might be used to measure the position of the accumulated beam. We report calculations and experimental results for some low frequency processing systems

  19. Computer control of the ISX-B neutral injection beamlines

    International Nuclear Information System (INIS)

    A system of controls for the Impurity Study Experiment (ISX-B) neutral injection beamlines at the Oak Ridge National Laboratory is presented. The system uses standard CAMAC equipment interfaced to the actual beamline controls and driven by a PDP-11/34 mini-computer. It is designed to relieve the operator of most of the mundane tasks of beam injection and also to reduce the number of operators needed to monitor multiple beamlines

  20. Development of visual beam adjustment method for cyclotron

    International Nuclear Information System (INIS)

    We have developed a computer-based visual assistance system for JAERI AVF-cyclotron operation. This system provides a CRT display about the cyclotron beam trajectories, feasible setting regions (FSR's), and search traces designed to enhance beam parameter adjustment. As a result of the test in actual operation, it was realized that simulated beam trajectories and FSR's were nearly agreeable with actual beam condition in the axial injection block and the extraction block. (author)

  1. Analysis of transmission efficiency of SSRF electron beam transfer lines

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In this article, the main factors which influence transmission efficiency of the SSRF electron beam transfer lines are described, including physical requirements for magnet system, vacuum system, beam diagnostic system,trajectory correction system, etc. The dynamic simulation calculation and transmission efficiency analysis of the SSRF electron beam transfer lines are presented, and the studies show that the design purpose of efficient beam transmission and injection will be achieved.

  2. Electron beam time-of-flight plasma potential diagnostic

    International Nuclear Information System (INIS)

    A time-of-flight method for measuring electrostatic potentials in plasmas using a modulated electron beam has been developed. The beam is injected along the magnetic field in a cylindrical plasma geometry. The phase of the electron beam modulation is detected using a Rogowski loop which encircles the beam and plasma, and the phase information is in turn related to the electrostatic potential. Measurements in vacuum and in plasma have been performed

  3. Injection and acceleration system of pulsed racetrack microtron

    International Nuclear Information System (INIS)

    Paper describes a pulsed racetrack microtron (RM) with 70 MeV beam maximal power. For this project one designed rare-earth permanent magnet base bending magnets, pattern to inject a bunched electron bean through a compact α-magnet and prismatic biperiodic accelerating structure (PBAS) characterized by compact transverse dimensions ensuring bar-free passing of electron beam through the first orbit. Besides, the PBAS has a high-frequency quadrupole focusing. These features facilitate essentially RM design and adjustment. Paper describes tests, technique of adjustment and of measuring of systems to inject and to accelerate a pulsed racetrack microtron

  4. TRANSVERSE PHASE SPACE PAINTING FOR SNS ACCUMULATOR RING INJECTION.

    Energy Technology Data Exchange (ETDEWEB)

    BEEBE-WANG,J.; LEE,Y.Y.; RAPARIA,D.; WEI,J.

    1999-03-29

    The result of investigation and comparison of a series of transverse phase space painting schemes for the injection of SNS accumulator ring [1] is reported. In this computer simulation study, the focus is on the creation of closed orbit bumps that give desired distributions at the target. Space charge effects such as tune shift, emittance growth and beam losses are considered. The results of pseudo end-to-end simulations from the injection to the target through the accumulator ring and Ring to Target Beam Transfer (RTBT) system [2] are presented and discussed.

  5. Injection and acceleration system of pulsed racetrack microtron

    CERN Document Server

    Ermakov, A N; Ishkhanov, B S

    2002-01-01

    Paper describes a pulsed racetrack microtron (RM) with 70 MeV beam maximal power. For this project one designed rare-earth permanent magnet base bending magnets, pattern to inject a bunched electron bean through a compact alpha-magnet and prismatic biperiodic accelerating structure (PBAS) characterized by compact transverse dimensions ensuring bar-free passing of electron beam through the first orbit. Besides, the PBAS has a high-frequency quadrupole focusing. These features facilitate essentially RM design and adjustment. Paper describes tests, technique of adjustment and of measuring of systems to inject and to accelerate a pulsed racetrack microtron

  6. Sodium Ferric Gluconate Injection

    Science.gov (United States)

    ... are also receiving the medication epoetin (Epogen, Procrit). Sodium ferric gluconate injection is in a class of medications called iron replacement products. It works by replenishing iron stores so ...

  7. Corticotropin, Repository Injection

    Science.gov (United States)

    ... protein in the blood; high levels of certain fats in the blood; and swelling of the arms, hands, feet, and legs). Corticotropin repository injection is in a class of medications called hormones. ...

  8. Collagenase Clostridium Histolyticum Injection

    Science.gov (United States)

    ... disease (a thickening of tissue [plaque] inside the penis that causes the penis to curve). Collagenase Clostridium histolyticum injection is in ... the plaque of thickened tissue and allows the penis to be straightened.

  9. Giving an insulin injection

    Science.gov (United States)

    ... medlineplus.gov/ency/patientinstructions/000660.htm Giving an insulin injection To use the sharing features on this ... and syringes. Filling the Syringe - One Type of Insulin Wash your hands with soap and water. Dry ...

  10. Botulinum toxin injection - larynx

    Science.gov (United States)

    Injection laryngoplasty; Botox-larynx: spasmodic dysphonia-BTX; Essential voice tremor (EVT)-btx; Glottic insufficiency; Percutaneous electromyography-guided botulinum toxin treatment; Percutaneous indirect laryngoscopy-guided botulinum toxin Treatment; ...

  11. Meperidine Hydrochloride Injection

    Science.gov (United States)

    ... drug will be either injected into a large muscle (such as your buttock or hip) or added ... lung or thyroid disease, heart disease, seizures, prostatic hypertrophy, or urinary problems.tell your doctor if you ...

  12. Application of diamond based beam loss monitors

    International Nuclear Information System (INIS)

    The LHC has an operational stored energy of 130MJ per beam. Only a small percentage of beam losses in the LHC equipment can damage material or lead to magnet quenches. Therefore, it is important to monitor different types of beam losses, e.g. scattering on residual gas particles, UFOs, collisions and injection losses. A detailed understanding of beam loss mechanisms is necessary to reduce them and ensure save operation. Two different beam loss monitors are installed in the LHC tunnel: ionization chambers and diamond sensors. Ionization chambers trigger a beam dump if beam losses exceed a certain threshold. They have a time resolution of 40um (half LHC turn) which is not sufficient to resolve bunch-by-bunch beam losses. Diamond sensors have a nanosecond time resolution and can therefore detect bunch-by-bunch beam losses. This time resolution allows an analysis of various types of beam losses and an understanding of the mechanisms. For the first time beam loss intensities were measured bunch-by-bunch caused by different origins of losses. Beam loss measurements using diamond sensors will be presented. The results are compared to simulations and good qualitative agreement was found. The potential of diamond sensors for LHC and experiment applications are discussed.

  13. Application of diamond based beam loss monitors

    Energy Technology Data Exchange (ETDEWEB)

    Hempel, Maria [Brandenburgische Technische Univ. Cottbus (Germany); DESY, Zeuthen (Germany); CERN, Geneva (Switzerland); Baer, Tobias [CERN, Geneva (Switzerland); Hamburg Univ. (Germany); Castro Carballo, Elena Maria [DESY, Zeuthen (Germany); Lohmann, Wolfgang [Brandenburgische Technische Univ. Cottbus (Germany); DESY, Zeuthen (Germany); Schmidt, Ruediger [CERN, Geneva (Switzerland)

    2013-07-01

    The LHC has an operational stored energy of 130MJ per beam. Only a small percentage of beam losses in the LHC equipment can damage material or lead to magnet quenches. Therefore, it is important to monitor different types of beam losses, e.g. scattering on residual gas particles, UFOs, collisions and injection losses. A detailed understanding of beam loss mechanisms is necessary to reduce them and ensure save operation. Two different beam loss monitors are installed in the LHC tunnel: ionization chambers and diamond sensors. Ionization chambers trigger a beam dump if beam losses exceed a certain threshold. They have a time resolution of 40um (half LHC turn) which is not sufficient to resolve bunch-by-bunch beam losses. Diamond sensors have a nanosecond time resolution and can therefore detect bunch-by-bunch beam losses. This time resolution allows an analysis of various types of beam losses and an understanding of the mechanisms. For the first time beam loss intensities were measured bunch-by-bunch caused by different origins of losses. Beam loss measurements using diamond sensors will be presented. The results are compared to simulations and good qualitative agreement was found. The potential of diamond sensors for LHC and experiment applications are discussed.

  14. Soft tissue injections

    OpenAIRE

    Inês, Luís P. B. S.; Silva, José António P. da

    2005-01-01

    Soft tissue rheumatism includes a wide spectrum of common lesions of the tendons, enthesis, tendon sheaths, bursae, ligaments and fasciae as well as nerve compression syndromes. Studies on the pathogenesis of these lesions do not support a major role for inflammation, thus questioning the rationale for glucocorticoid injections. This chapter reviews current indications for local glucocorticoid injections and available evidence on its efficacy, as well as contraindications and potential risks....

  15. Feline injection site sarcomas

    OpenAIRE

    Nóbrega, C.; Mesquita, Jr.; Cruz, R; C. Coelho; Esteves, F.; Mega, A. C.; Santos, C.; Vala, Helena

    2016-01-01

    Feline injection site sarcoma (FISS), formerly known as Vaccine Associated Sarcoma (VAS) is a rare, but life-threatening disease. The incidence estimates have varied from 1 case of FISS per 1,000-10,000 cats vaccinated in North America and between 1 per 5,000-12,500 vaccination visits in United Kingdom. It has been primarily associated with vaccine administration, but several other injectable materials/substances have been implicated as aetiologic agents, namely lufenuron, penicilin, meti...

  16. Measurements of beam-ion confinement during tangential beam-driven instabilities in PBX [Princeton Beta Experiment

    International Nuclear Information System (INIS)

    During tangential injection of neutral beams into low density tokamak plasmas with β > 1% in the Princeton Beta Experiment (PBX), instabilities are observed that degrade the confinement of beam ions. Neutron, charge-exchange, and diamagnetic loop measurements are examined in order to identify the mechanism or mechanisms responsible for the beam-ion transport. The data suggest a resonant interaction between the instabilities and the parallel energetic beam ions. Evidence for some nonresonant transport also exists

  17. Molecular beams

    International Nuclear Information System (INIS)

    This book is a timeless and rather complete theoretical and experimental treatment of electric and magnetic resonance molecular-beam experiments for studying the radio frequency spectra of atoms and molecules. The theory of interactions of the nucleus with atomic and molecular fields is extensively presented. Measurements of atomic and nuclear magnetic moments, electric multipole moments, and atomic fine and hyperfine structure are detailed. Useful but somewhat outdated chapters on gas kinetics, molecular beam design, and experimental techniques are also included

  18. Beam-induced tensor pressure tokamak equilibria

    International Nuclear Information System (INIS)

    D-shaped tensor pressure tokamak equilibria induced by neutral-beam injection are computed. The beam pressure components are evaluated from the moments of a distribution function that is a solution of the Fokker-Planck equation in which the pitch-angle scattering operator is ignored. The level-psub(perpendicular) contours undergo a significant shift away from the outer edge of the device with respect to the flux surfaces for perpendicular beam injection into broad-pressure-profile equilibria. The psub(parallel) contours undergo a somewhat smaller inward shift with respect to the flux surfaces for both parallel and perpendicular injection into broad-pressure-profile equilibria. For peaked-pressure-profile equilibria, the level pressure contours nearly co-incide with the flux surfaces. (author)

  19. Low emittance electron beam optics commissioning in Indus-2

    International Nuclear Information System (INIS)

    Currently Indus-2 is normally operated with beam emittance of 85 nmrad at 2.0 GeV. In order to reduce the beam emittance to half of this value its dispersion function has been modified by properly choosing the quadrupoles strengths of the lattice. At this low beam emittance optics dynamic aperture reduces and may not be sufficient for beam injection thus a procedure has been evolved and implemented to shift the beam emittance of stored beam at 2.0 GeV. (author)

  20. Tomography at Injection in the PSB

    CERN Document Server

    Hancock, Steven

    2016-01-01

    The PSB was conceived as an intensity booster for fixed-target physics. Consequently, no attempt was ever made to synchronize the turns injected into each ring with the rf in that ring because as many as a dozen such turns were expected to be superposed longitudinally [1]. When only a small, non-integer number of turns is injected, this asynchronism results in a particle distribution whose initial phase fluctuates wildly from shot to shot with respect to the rf bucket into which it is subsequently captured. This has long been suspected to be an ingredient in the intensity non-reproducibility observed for low-intensity beams, such as pilot beams for the LHC [2]. An MD cycle has been built to pursue this suspicion (in one ring, at least) by introducing, in a fully ppm fashion, distributor timings that are first resynchronized to the rf train of Ring3 and that then count 40 MHz clock ticks to reduce any jitter to just 25 ns (cf., the bucket duration at Booster injection is 1.67 μs). Leaving aside the origin...

  1. Beam emittance and beam disruption

    International Nuclear Information System (INIS)

    Beam disruption during the collision of intense relativistic bunches has been studied by R. Hollebeek. In the case of oppositely charged bunches, focussing effects occur causing a decrease in the effective bunch cross section, and thereby an increase of luminosity by an enhancement factor H. The term disruption derives from the fact that the beam emittance changes markedly during the collision. 1 ref., 1 fig., 1 tab

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-10-01

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

  3. Active Stabilization of a Diode Laser Injection Lock

    CERN Document Server

    Saxberg, Brendan; Gupta, Subhadeep

    2016-01-01

    We report on a device to electronically stabilize the optical injection lock of a semiconductor diode laser. Our technique uses as discriminator the peak height of the laser's transmission signal on a scanning Fabry-Perot cavity and feeds back to the diode current, thereby maintaining maximum optical power in the injected mode. A two-component feedback algorithm provides constant optimization of the injection lock, keeping it robust to slow thermal drifts and allowing fast recovery from sudden failures such as temporary occlusion of the injection beam. We demonstrate the successful performance of our stabilization method in a diode laser setup at 399 nm used for laser cooling of Yb atoms. The device eases the requirements on passive stabilization and can benefit any diode laser injection lock application, particularly those where several such locks are employed.

  4. Active stabilization of a diode laser injection lock

    Science.gov (United States)

    Saxberg, Brendan; Plotkin-Swing, Benjamin; Gupta, Subhadeep

    2016-06-01

    We report on a device to electronically stabilize the optical injection lock of a semiconductor diode laser. Our technique uses as discriminator the peak height of the laser's transmission signal on a scanning Fabry-Perot cavity and feeds back to the diode current, thereby maintaining maximum optical power in the injected mode. A two-component feedback algorithm provides constant optimization of the injection lock, keeping it robust to slow thermal drifts and allowing fast recovery from sudden failures such as temporary occlusion of the injection beam. We demonstrate the successful performance of our stabilization method in a diode laser setup at 399 nm used for laser cooling of Yb atoms. The device eases the requirements on passive stabilization and can benefit any diode laser injection lock application, particularly those where several such locks are employed.

  5. Rf capture studies for injection into a synchrotron

    International Nuclear Information System (INIS)

    The capture process for a rapid cycling protron synchrotron is studied by numerical simulation. The rf-programming is optimized to allow efficient capture such that minimum particle losses and reasonable capture voltage are attained. The total capture time is constrained to be less than 700 μseconds. Two methods of trapping the injected beam by the synchrotron rf system are examined: by stationary adiabatic capture and by synchronous injection in a standing bucket of the ring. In the adiabatic method, the non-linear function of Lilliequist and Symon is employed. The simulation allows the ''tracking back'' of the original distribution of any set of particles, in particular of those not captured at a given time, which is useful in studying injection alternatives such as shaping the phase-space density prior to injection. The simulation results will be used to design a chopper system to facilitate loss-free injection

  6. Beam loading compensation with variable group velocity

    International Nuclear Information System (INIS)

    Consider a section with linearly variable group velocity and a beam pulse shorter than the section fill time. Choose the current amplitude so that the gradient of the last bunch equals the gradient of the first bunch. For beam pulses less than about 15% of fill time, the voltage deviation during the beam pulse is small, but as the pulse width increases the voltage deviation also increases. We show that by decreasing the output to input group velocity ratio, we can reduce the first order voltage deviation, and that we can remove the remaining second-order voltage deviation by linearly decreasing the section input power by a small amount starting at beam injection time. This way we can increase the beam pulse width to more than half the fill time, and thereby increase the RF to beam energy transfer efficiency and the luminosity without increasing the voltage deviation

  7. Syringe-injectable electronics

    Science.gov (United States)

    Liu, Jia; Fu, Tian-Ming; Cheng, Zengguang; Hong, Guosong; Zhou, Tao; Jin, Lihua; Duvvuri, Madhavi; Jiang, Zhe; Kruskal, Peter; Xie, Chong; Suo, Zhigang; Fang, Ying; Lieber, Charles M.

    2015-07-01

    Seamless and minimally invasive three-dimensional interpenetration of electronics within artificial or natural structures could allow for continuous monitoring and manipulation of their properties. Flexible electronics provide a means for conforming electronics to non-planar surfaces, yet targeted delivery of flexible electronics to internal regions remains difficult. Here, we overcome this challenge by demonstrating the syringe injection (and subsequent unfolding) of sub-micrometre-thick, centimetre-scale macroporous mesh electronics through needles with a diameter as small as 100 μm. Our results show that electronic components can be injected into man-made and biological cavities, as well as dense gels and tissue, with >90% device yield. We demonstrate several applications of syringe-injectable electronics as a general approach for interpenetrating flexible electronics with three-dimensional structures, including (1) monitoring internal mechanical strains in polymer cavities, (2) tight integration and low chronic immunoreactivity with several distinct regions of the brain, and (3) in vivo multiplexed neural recording. Moreover, syringe injection enables the delivery of flexible electronics through a rigid shell, the delivery of large-volume flexible electronics that can fill internal cavities, and co-injection of electronics with other materials into host structures, opening up unique applications for flexible electronics.

  8. Alpha-particle diagnostics with high energy neutral beams

    International Nuclear Information System (INIS)

    We have examined the feasibility of alpha-particle diagnostics using a high energy neutral beam on the R-tokamak, a planned device at IPP-Nagoya, Japan, for reacting plasma experiments. In this method, injected neutral particles neutralize alpha particles so as to escape from the magnetically confined plasma through double charge exchange processes, He++ + A0 -- → He0 + A++. Requirements for a probing beam are dis cussed from viewpoints of penetration of an injected beam in the plasma and a neutralization efficiency of alpha particles in a wide velocity range. Either a Li0 beam or a He0 beam in the ground state, produced from a negative ion beam is suitable. A method to neutralize a He- beam into the ground state through an auto-detachment process is proposed. (author)

  9. Progress of beam diagnosis system for EAST neutral beam injector

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Y. J., E-mail: yjxu@ipp.ac.cn; Hu, C. D.; Yu, L.; Liang, L. Z.; Zhang, W. T.; Chen, Y.; Li, X. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2016-02-15

    Neutral beam injection has been recognized as one of the most effective means for plasma heating. According to the research plan of the EAST physics experiment, two sets of neutral beam injector (NBI) were built and operational in 2014. The paper presents the development of beam diagnosis system for EAST NBI and the latest experiment results obtained on the test-stand and EAST-NBI-1 and 2. The results show that the optimal divergence angle is (0.62°, 1.57°) and the full energy particle is up to 77%. They indicate that EAST NBI work properly and all targets reach or almost reach the design targets. All these lay a solid foundation for the achievement of high quality plasma heating for EAST.

  10. Laser Doppler instrument measures fluid velocity without reference beam

    Science.gov (United States)

    Bourquin, K. R.; Shigemoto, F. H.

    1971-01-01

    Fluid velocity is measured by focusing laser beam on moving fluid and measuring Doppler shift in frequency which results when radiation is scattered by particles either originally present or deliberately injected into moving fluid.

  11. First beam test of ΔΦ-A initial beam loading compensation for electron linacs

    International Nuclear Information System (INIS)

    The initial-beam-loading effect may cause serious beam loss in the electron linac of the Super SOR light source. Because of the large energy spread, it is difficult to compensate the beam loading with ordinary methods, such as the adjustment of injection timing and ECS (Energy Compensation System). A phase-amplitude (ΔΦ-A) modulation system has already been developed and tested. First beam test using this system was carried out at the 125 MeV electron linac of Laboratory for Electron Beam Research and Application (LEBRA) in Nihon University. Its result shows that our system well corrects the energy spread due to initial beam loading effect. In this paper, we report the results of first beam test. (author)

  12. Reactor water injection facility

    International Nuclear Information System (INIS)

    A steam turbine and an electric generator are connected by way of a speed convertor. The speed convertor is controlled so that the number of rotation of the electric generator is constant irrespective of the speed change of the steam turbine. A shaft coupler is disposed between the turbine and the electric generator or between the turbine and a water injection pump. With such a constitution, the steam turbine and the electric generator are connected by way of the speed convertor, and since the number of revolution of the electric generator is controlled to be constant, the change of the number of rotation of the turbine can be controlled irrespective of the change of the number of rotation of the electric generator. Accordingly, the flow rate of the injection water from the water injection pump to a reactor pressure vessel can be controlled freely thereby enabling to supply stable electric power. (T.M.)

  13. LHC Report: The beam is back at the LHC

    CERN Multimedia

    Reyes Alemany

    2015-01-01

    A series of sector beam tests paved the way for the start-up of the LHC in 2008 and 2009. These tests and the follow-up of the issues that arose were part of the process that led to a smooth start-up with beam.   Given this experience, sector tests were scheduled to take place several weeks before the 2015 start-up. On the weekend of 6-9 March, beam from the SPS was injected into both LHC injection regions, followed by a first pass through the downstream LHC sectors. For the clockwise LHC beam (called “beam 1”) this meant passing through ALICE and into Sector 2-3, while the anticlockwise beam (called “beam 2”) was threaded through LHCb and all the way from Point 8 to Point 6, where it was extracted by the beam dump kickers onto the beam dump block. The dry runs in the previous weeks were mainly targeted at preparation for the sector tests. The systems tested included: injection, timing, synchronisation and beam instrumentation. The beam interlock ...

  14. Study of the temporary capture of an electron beam in magnetic mirror configuration

    International Nuclear Information System (INIS)

    A method of injection is studied which is intermediate between the purely transverse injection used in MMII (magnetic mirror device for ion injection) and the longitudinal injection used in CAPEL. The investigation of the conditions of injection of an electron beam has shown the possibility of capturing temporarily a beam approximately 1 cm in width. The mean length of the captured trajectories is about fifty meters. A uniform perturbation of the magnetic field which destroys the axial symmetry does not appreciably modify the length of captured trajectories. This method of injection, which we call 'conical', is interesting because a large proportion of the injected beam is captured (about 80 per cent), and this capture is obtained with injection conditions that are not critical. (author)

  15. Antiproton source beam position system

    International Nuclear Information System (INIS)

    The TeV I Beam Position Monitor (BPM) system is designed to provide a useful diagnostic tool during the commissioning and operational phases of the antiproton source. Simply stated the design goal is to provide single turn position information for intensities of > 1x109 particles, and multi-turn (clocked orbit) information for beam intensities of > 1x107 particles, both with sub-millimeter resolution. It is anticipated that the system will be used during commissioning for establishing the first turn through the Debuncher and Accumulator, for aligning injection orbits, for providing information necessary to correct closed orbits, and for measuring various machine parameters (e.g. tunes, dispersion, aperture, chromaticity). During normal antiproton operation the system will be used to monitor the beam position throughout the accumulation process

  16. An injection system for a linear accelerator

    International Nuclear Information System (INIS)

    An injection system for the Linear Accelerator is developed using the parameters of machines at the Centro Brasileiro de Pesquisas Fisicas and the Instituto Militar de Engenharia. The proposed system consists basically of a prebuncher and a chopper. The pre-buncher is used to improve the energy resolution and also to increase the accelerator target current. The chopper is used to remove from the beam the electrons that have no possibility of attaining the desired energy and that are usually lost in the walls and the cavity tube, thus producing undesirable background. Theoretical development of the chopper is performed in order to obtain its dimensions for future construction. The complete design the pre-buncher and its feed supply system and the experimental verication of its performance are also presented. It is intended to give the necessary information for the design and construction of the complete injection system proposed. (Author)

  17. Neutral beam heating for jet, construction and test of a quasi-stationary plasma heating system at the 10 MW level

    International Nuclear Information System (INIS)

    Neutral beam injection is one of the two heating methods for JET. During the first stage of operation hydrogen beams will be injected at 80 keV with a beam pulse length of 10 s. The total beam power into the Torus is 18 MW with 10 MW in the full energy beam component. The power will be provided from 16 beam sources with an extracted ion beam current of 60 A each, arranged in two systems of 8 sources. For the second stage of operation the system will be modified to 160 keV deuterium beams, with 30 A extracted beam current per source. (orig.)

  18. 200 MeV RF linac for synchrotron injection

    International Nuclear Information System (INIS)

    Construction has been completed on an electron linear accelerator for the Brookhaven National Laboratory. This accelerator will be used for the injection of a 200 MeV electron beam into a synchrotron for lithography experiments. This paper describes the conceptual design of the linac, its e-gun pulser, and its control and timing systems. 3 figs., ref

  19. Injecting a Kapchinskij-Vladimirskij distribution into a proton synchrotron

    International Nuclear Information System (INIS)

    Recently it has been suggested that the Kapchinskij Vladimirskij (KV) distribution may be of practical interest for high intensity machines in that it may provide the maximum space charge limit for such a machine. One can be make a plausible argument that the maximum beam intensity is obtained for a distribution for which all particles have the same tune, at least when the resonance is approached. Therefore, the following steps should be taken: first, reduce the chromaticity of the accelerator ring as much as possible, and second, make the betatron frequencies independent of amplitude, i.e., make the focusing forces linear. One way to make the focusing forces linear is to start with external focusing forces which are linear, and then make the space charge forces also linear by using a K-V distribution. Sections II and III describe two injection scenarios which produce a KV distribution (if we neglect beam-beam interactions during the injection process.) Simulations of these injection scenarios verify that the resulting distribution produces a uniform circular beam in xy-space. A simulation code was written which also includes the space charge interactions between the 500 injected turns in the proposed scenarios; the results are given in section IV. The space charge forces have a substantial effect on the resulting distribution

  20. Method for Converter Synchronization with RF Injection

    Directory of Open Access Journals (Sweden)

    Joshua P. Bruckmeyer

    2015-09-01

    Full Text Available This paper presents an injection method for synchronizing analog to digital converters (ADC. This approach can eliminate the need for precision routed discrete synchronization signals of current technologies, such as JESD204. By eliminating the setup and hold time requirements at the conversion (or near conversion clock rate, higher sample rate systems can be synchronized. Measured data from an existing multiple ADC conversion system was used to evaluate the method. Coherent beams were simulated to measure the effectiveness of the method. The results show near theoretical coherent processing gain.