WorldWideScience

Sample records for beam injection

  1. Cluster beam injection

    International Nuclear Information System (INIS)

    Bottiglioni, F.; Coutant, J.; Fois, M.

    1977-11-01

    Areas of possible applications of cluster injection are discussed. The deposition inside the plasma of molecules, issued from the dissociation of the injected clusters, has been computed. Some empirical scaling laws for the penetration are given

  2. Cluster beam injection

    International Nuclear Information System (INIS)

    Bottiglioni, F.; Coutant, J.; Fois, M.

    1978-01-01

    Areas of possible applications of cluster injection are discussed. The deposition inside the plasma of molecules, issued from the dissociation of the injected clusters, has been computed. Some empirical scaling laws for the penetration are given

  3. BEAMS3D Neutral Beam Injection Model

    Energy Technology Data Exchange (ETDEWEB)

    Lazerson, Samuel

    2014-04-14

    With the advent of applied 3D fi elds in Tokamaks and modern high performance stellarators, a need has arisen to address non-axisymmetric effects on neutral beam heating and fueling. We report on the development of a fully 3D neutral beam injection (NBI) model, BEAMS3D, which addresses this need by coupling 3D equilibria to a guiding center code capable of modeling neutral and charged particle trajectories across the separatrix and into the plasma core. Ionization, neutralization, charge-exchange, viscous velocity reduction, and pitch angle scattering are modeled with the ADAS atomic physics database [1]. Benchmark calculations are presented to validate the collisionless particle orbits, neutral beam injection model, frictional drag, and pitch angle scattering effects. A calculation of neutral beam heating in the NCSX device is performed, highlighting the capability of the code to handle 3D magnetic fields.

  4. ITER Neutral Beam Injection System

    International Nuclear Information System (INIS)

    Ohara, Yoshihiro; Tanaka, Shigeru; Akiba, Masato

    1991-03-01

    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)

  5. PLT neutral beam injection systems

    International Nuclear Information System (INIS)

    Menon, M.M.; Barber, G.C.; Blue, C.W.

    1979-01-01

    A brief description of the Princeton Large Torus (PLT) neutral beam injection system is given and its performance characteristics are outlined. A detailed operational procedure is included, as are some tips on troubleshooting. Proper operation of the source is shown to be a crucial factor in system performance

  6. Tevatron beam-beam simulations at injection energy

    Energy Technology Data Exchange (ETDEWEB)

    Meiqin Xiao; Bela Erdelyi; Tanaji Sen

    2003-05-28

    Major issues at Tevatron injection are the effects of 72 long-range beam-beam interactions together with the machine nonlinearity on protons and anti-protons. We look at particle tracking calculations of Dynamic Aperture (DA) under present machine conditions. Comparisons of calculations with observations and experiments are also presented in this report.

  7. Comparison of beam deposition for three neutral beam injection codes

    International Nuclear Information System (INIS)

    Wieland, R.M.; Houlberg, W.A.; Mense, A.T.

    1979-03-01

    The three neutral beam injection codes BEAM (Houlberg, ORNL), HOFR (Howe, ORNL), and FREYA (Post, PPPL) are compared with respect to the calculation of the fast ion deposition profile H(r). Only plasmas of circular cross section are considered, with injection confined to the mid-plane of the torus. The approximations inherent in each code are pointed out, and a series of comparisons varying several parameters (beam energy and radius, machine size, and injection angle) shows excellent agreement among all the codes. A cost comparison (execution time and memory requirements) is made which points out the relative merits of each code within the context of incorporation into a plasma transport simulation code

  8. Neutral beam injection in 2XIIB

    International Nuclear Information System (INIS)

    Hibbs, S.M.

    1975-01-01

    Integrated into the operation of the 2XIIB controlled fusion experiment is a 600-A, 20-keV neutral injection system: the highest neutral-beam current capacity of any existing fusion machine. This paper outlines the requirements of the injection system and the design features to which they led. Both mechanical and electrical aspects are discussed. Also included is a brief description of some operational aspects of the system and some of the things we have learned along the way, as well as a short history of the most significant developments

  9. Neutral beam injection optimization at TJ-II

    International Nuclear Information System (INIS)

    Fuentes, C.; Liniers, M.; Wolfers, G.; Alonso, J.; Marcon, G.; Carrasco, R.; Guasp, J.; Acedo, M.; Sanchez, E.; Medrano, M.; Garcia, A.; Doncel, J.; Alejaldre, C.; Tsai, C.C.; Barber, G.; Sparks, D.

    2005-01-01

    Neutral beam injection (NBI) heating has been used on the TJ-II stellarator for the first time. The beam has a port-through power between 200 and 400 kW and injection energy 28 kV. Beam transmission is limited by beam interception at the injection port and the first toroidal field coil, therefore, beam steering optimization is of critical importance. The beam interaction areas inside TJ-II vacuum chamber are surveyed by infrared thermography. Beam reionization can be a problem due to the presence of residual gas in the duct region. Halpha emission is used to monitor the reionization at the duct. A careful optimization of the injected gas has been carried out

  10. Simulations of Beam Injection and Extraction into Ion Sources

    CERN Document Server

    Cavenago, Marco

    2005-01-01

    Charge breeding, consistiting of injecting singly charged ion into ECRIS(Electron Cyclotron Resonance Ion Sources) to extract an highly charged ion beam, is a promising technique for rare or radioactive ion beam. Efficiency and extracted beam temperature are dominated by the strong collisional diffusion of charged ion inside source. A computer code, named BEAM2ECR, written to simulate details of the injection, ionization, collision and extraction processes is described.* A model of injection plasma sheath and of source fringe field were recently added. Neutral injection is also supported, for comparison with other techniques, like gas feeding or metal vapor injection. Results, clearly favouring near axis injection for most cases are described. Code is written in C-language and possibility of concurrent execution over a Linux cluster was recently added.

  11. Efficient Injection of Electron Beams into Magnetic Guide Fields

    International Nuclear Information System (INIS)

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

    1999-01-01

    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

  12. 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.

  13. LHC Injection Beam Quality During LHC Run I

    CERN Document Server

    AUTHOR|(CDS)2079186; Kain, Verena; 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...

  14. Electron beam injection during active experiments. I - Electromagnetic wave emissions

    Science.gov (United States)

    Winglee, R. M.; Kellogg, P. J.

    1990-01-01

    The wave emissions produced in Echo 7 experiment by active injections of electron beams were investigated to determine the properties of the electromagnetic and electrostatic fields for both the field-aligned and cross-field injection in such experiments and to evaluate the sources of free energy and relative efficiencies for the generation of the VLF and HF emissions. It is shown that, for typical beam energies in active experiments, electromagnetic effects do not substantially change the bulk properties of the beam, spacecraft charging, and plasma particle acceleration. Through simulations, beam-generated whistlers; fundamental z-mode and harmonic x-mode radiation; and electrostatic electron-cyclotron, upper-hybrid, Langmuir, and lower-hybrid waves were identified. The characteristics of the observed wave spectra were found to be sensitive to both the ratio of the electron plasma frequency to the cyclotron frequency and the angle of injection relative to the magnetic field.

  15. TPX Neutral Beam Injection System design

    International Nuclear Information System (INIS)

    von Halle, A.; Bowen, O.N.; Edwards, J.W.

    1993-01-01

    The existing Tokamak Fusion Test Reactor Neutral Beam system is proposed to be modified for long pulse operation on the Tokamak Physics Experiment (TPX). Day one of TPX will call for one TFTR beamline modified for 1000 second pulse lengths oriented co-directional to the plasma current. The system design will be capable of accommodating an additional co-directional and a single counter directional beamline. For the TPX conceptual design, every attempt was made to use existing Neutral Beam hardware, plant facilities, auxiliary systems, service infrastructure, and control systems. This paper describes the moderate modifications required to the power systems, the ion sources, and the beam impinged surfaces of the ion dumps, the calorimeters, the various beam scrapers, and the neutralizers. Also described are the minimal modifications required to the vacuum, cryogenic, and gas systems and the major modification of replacing the beamline-torus duct in its entirety. Operational considerations for Neutral Beam subsystems over 1000 second pulse lengths will be explored including proposed operating scenarios for full steady state operation

  16. Neutral beam injection and plasma convection in a magnetic field

    International Nuclear Information System (INIS)

    Okuda, H.; Hiroe, S.

    1988-06-01

    Injection of a neutral beam into a plasma in a magnetic field has been studied by means of numerical plasma simulations. It is found that, in the absence of a rotational transform, the convection electric field arising from the polarization charges at the edges of the beam is dissipated by turbulent plasma convection, leading to anomalous plasma diffusion across the magnetic field. The convection electric field increases with the beam density and beam energy. In the presence of a rotational transform, polarization charges can be neutralized by the electron motion along the magnetic field. Even in the presence of a rotational transform, a steady-state convection electric field and, hence, anomalous plasma diffusion can develop when a neutral beam is constantly injected into a plasma. Theoretical investigations on the convection electric field are described for a plasma in the presence of rotational transform. 11 refs., 19 figs

  17. First neutral beam injection experiments on KSTAR tokamak.

    Science.gov (United States)

    Jeong, S H; Chang, D H; Kim, T S; In, S R; Lee, K W; Jin, J T; Chang, D S; Oh, B H; Bae, Y S; Kim, J S; Park, H T; Watanabe, K; Inoue, T; Kashiwagi, M; Dairaku, M; Tobari, H; Hanada, M

    2012-02-01

    The first neutral beam (NB) injection system of the Korea Superconducting Tokamak Advanced Research (KSTAR) tokamak was partially completed in 2010 with only 1∕3 of its full design capability, and NB heating experiments were carried out during the 2010 KSTAR operation campaign. The ion source is composed of a JAEA bucket plasma generator and a KAERI large multi-aperture accelerator assembly, which is designed to deliver a 1.5 MW, NB power of deuterium at 95 keV. Before the beam injection experiments, discharge, and beam extraction characteristics of the ion source were investigated. The ion source has good beam optics in a broad range of beam perveance. The optimum perveance is 1.1-1.3 μP, and the minimum beam divergence angle measured by the Doppler shift spectroscopy is 0.8°. The ion species ratio is D(+):D(2)(+):D(3)(+) = 75:20:5 at beam current density of 85 mA/cm(2). The arc efficiency is more than 1.0 A∕kW. In the 2010 KSTAR campaign, a deuterium NB power of 0.7-1.5 MW was successfully injected into the KSTAR plasma with a beam energy of 70-90 keV. L-H transitions were observed within a wide range of beam powers relative to a threshold value. The edge pedestal formation in the T(i) and T(e) profiles was verified through CES and electron cyclotron emission diagnostics. In every deuterium NB injection, a burst of D-D neutrons was recorded, and increases in the ion temperature and plasma stored energy were found.

  18. First neutral beam injection experiments on KSTAR tokamaka)

    Science.gov (United States)

    Jeong, S. H.; Chang, D. H.; Kim, T. S.; In, S. R.; Lee, K. W.; Jin, J. T.; Chang, D. S.; Oh, B. H.; Bae, Y. S.; Kim, J. S.; Park, H. T.; Watanabe, K.; Inoue, T.; Kashiwagi, M.; Dairaku, M.; Tobari, H.; Hanada, M.

    2012-02-01

    The first neutral beam (NB) injection system of the Korea Superconducting Tokamak Advanced Research (KSTAR) tokamak was partially completed in 2010 with only 1/3 of its full design capability, and NB heating experiments were carried out during the 2010 KSTAR operation campaign. The ion source is composed of a JAEA bucket plasma generator and a KAERI large multi-aperture accelerator assembly, which is designed to deliver a 1.5 MW, NB power of deuterium at 95 keV. Before the beam injection experiments, discharge, and beam extraction characteristics of the ion source were investigated. The ion source has good beam optics in a broad range of beam perveance. The optimum perveance is 1.1-1.3 μP, and the minimum beam divergence angle measured by the Doppler shift spectroscopy is 0.8°. The ion species ratio is D+:D2+:D3+ = 75:20:5 at beam current density of 85 mA/cm2. The arc efficiency is more than 1.0 A/kW. In the 2010 KSTAR campaign, a deuterium NB power of 0.7-1.5 MW was successfully injected into the KSTAR plasma with a beam energy of 70-90 keV. L-H transitions were observed within a wide range of beam powers relative to a threshold value. The edge pedestal formation in the Ti and Te profiles was verified through CES and electron cyclotron emission diagnostics. In every deuterium NB injection, a burst of D-D neutrons was recorded, and increases in the ion temperature and plasma stored energy were found.

  19. Characteristics of Injected Beam at HIMAC Synchrotron

    CERN Document Server

    Uesugi, Takehiro; Noda, Koji; Shibuya, Shinji

    2005-01-01

    At the HIMAC synchrotron, we have carried out the tune survey with the lifetime measurement in order to obtain the high intensity. Under the relatively high intensity, it was observed that a part of the circulating beam was lost due to the coherent oscillation in both the horizontal and the vertical direction. Taking account of the tune shift and spreads, the working point was optimized so as to avoid resonance line. We will describe the experimental result.

  20. Investigation of vortex laser beam injection into an optical fiber

    Science.gov (United States)

    Savelyev, D. A.; Khonina, S. N.

    2017-11-01

    We investigate Laguerre-Gaussian vortex laser beam injection into an optical fiber. Modelling of radiation entering an optical fiber with plane (cylinder) and axicon (cone with diffrent apex angle) micro-relief is numerically investigated by the finite difference time domain (FDTD) method.

  1. The model of beam-plasma discharge in the rocket environment during an electron beam injection in the ionosphere

    International Nuclear Information System (INIS)

    Mishin, E.V.; Ruzhin, Yu.Ya.

    1980-01-01

    The model of beam-plasma discharge in the rocket environment during electron beam injection in the ionosphere is constructed. The discharge plasma density dependence on the neutral gas concentration and the beam parameters is found

  2. Neutral-beam-injected tokamak fusion reactors: a review

    International Nuclear Information System (INIS)

    Jassby, D.L.

    1976-08-01

    The theories of energetic-ion velocity distributions, stability, injection, and orbits were summarized. The many-faceted role of the energetic ions in plasma heating, fueling, and current maintenance, as well as in the direct enhancement of fusion power multiplication and power density, is discussed in detail for three reactor types. The relevant implications of recent experimental results on several beam-injected tokamaks are examined. The behavior of energetic ions is found to be in accordance with classical theory, large total ion energy densities are readily achieved, and plasma equilibrium and stability are maintained. The status of neutral-beam injectors and of conceptual design studies of beam-driven reactors are briefly reviewed. The principal plasma-engineering problems are those associated directly with achieving quasi-stationary operation

  3. Transport investigations during neutral-beam injection, ion cyclotron heating and pellet injection experiments on TFR

    International Nuclear Information System (INIS)

    1985-01-01

    Neutral-beam injection and ion cyclotron frequency heating experiments have been carried out successively on TFR with inconel and carbon limiters. Heating efficiencies are for both methods lower with carbon limiters than with inconel. In the case of neutral-beam injection, the ion temperature saturation is supposed to be due to fast-ion charge-exchange losses. The electron temperature saturation is, in the two cases, correlated with small-scale density fluctuation enhancement. The difficulty of deeply modifying the electron temperature profile is also observed during pellet injection. These observations suggest that even slight modifications of the electron temperature gradients lead to enhanced transport. The role of plasma/wall interaction and recycling has not been clarified, but could be important, in particular with carbon limiters. (author)

  4. Neutral Beam Injection for Plasma and Magnetic Field Diagnostics

    International Nuclear Information System (INIS)

    Vainionpaa, Jaakko Hannes; Leung, Ka Ngo; Kwan, Joe W.; Levinton, Fred

    2007-01-01

    At the Lawrence Berkeley National Laboratory (LBNL) a diagnostic neutral beam injection system for measuring plasma parameters, flow velocity, and local magnetic field is being developed. High proton fraction and small divergence is essential for diagnostic neutral beams. In our design, a neutral hydrogen beam with an 8 cm x 11 cm (or smaller) elliptical beam spot at 2.5 m from the end of the extraction column is produced. The beam will deliver up to 5 A of hydrogen beam to the target with a pulse width of ∼1 s, once every 1-2 min. The H1+ ion species of the hydrogen beam will be over 90 percent. For this application, we have compared two types of RF driven multicusp ion sources operating at 13.56MHz. The first one is an ion source with an external spiral antenna behind a dielectric RF-window. The second one uses an internal antenna in similar ion source geometry. The source needs to generate uniform plasma over a large (8 cm x 5 cm) extraction area. We expect that the ion source with internal antenna will be more efficient at producing the desired plasma density but might have the issue of limited antenna lifetime, depending on the duty factor. For both approaches there is a need for extra shielding to protect the dielectric materials from the backstreaming electrons. The source walls will be made of insulator material such as quartz that has been observed to generate plasma with higher atomic fraction than sources with metal walls. The ion beam will be extracted and accelerated by a set of grids with slits, thus forming an array of 6 sheet-shaped beamlets. The multiple grid extraction will be optimized using computer simulation programs. Neutralization of the beam will be done in neutralization chamber, which has over 70 percent neutralization efficiency

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

    International Nuclear Information System (INIS)

    Cooper, W.S.; Elischer, V.P.; Goldberg, D.A.; Hopkins, D.B.; Jacobson, V.L.; Lou, K.H.; Tanabe, J.T.

    1981-03-01

    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. Development of the ion source for PDX neutral beam injection

    International Nuclear Information System (INIS)

    Menon, M.M.; Tsai, C.C.; Gardner, W.L.; Barber, G.C.; Haselton, H.H.; Ponte, N.S.; Ryan, P.M.; Schechter, D.E.; Stirling, W.L.; Whealton, J.H.

    1979-01-01

    The paper describes the development of the ion source for neutral beam injection heating of PDX plasma. After a brief description of the plasma generator, the performance characteristics of the source, with different types of grids, are described. Based on test stand results it is concluded that at least two different versions of the source should be able to meet and even exceed the neutral power and energy requirements expected out of PDX injectors

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

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, W.S.; Elischer, V.P.; Goldberg, D.A.; Hopkins, D.B.; Jacobson, V.L.; Lou, K.H.; Tanabe, J.T.

    1981-03-01

    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.

  8. The Beam Screen for the LHC Injection Kicker Magnets

    CERN Document Server

    Barnes, MJ; Ducimetière, L; Garrel, N; Kroyer, T

    2006-01-01

    The two LHC injection kicker magnet systems must each produce a kick of 1.2 T.m with a flattop duration variable up to 7.86 ìs, and rise and fall times of less than 0.9 ìs and 3 ìs, respectively. Each system is composed of four 5 Ù transmission line kicker magnets with matched terminating resistors and pulse forming networks (PFN). The LHC beam has a high intensity, hence a beam screen is required in the aperture of the magnets This screen consists of a ceramic tube with conducting ?stripes? on the inner wall. The stripes provide a path for the image current of the beam and screen the magnet ferrites against Wake fields. The stripes initially used gave adequately low beam impedance however stripe discharges occured during pulsing of the magnet: hence further development of the beam screen was undertaken. This paper presents options considered to meet the often conflicting needs for low beam impedance, shielding of the ferrite, fast field rise time and good electrical and vacuum behaviour.

  9. Oblate Field-Reversed Configuration Experiments with Neutral Beam Injection

    Science.gov (United States)

    T., II; Gi, K.; Umezawa, T.; Inomoto, M.; Ono, Y.

    2011-11-01

    The effect of energetic beam ions on oblate Field-Reversed Configurations (FRCs) has been studied experimentally in the TS-4 plasma merging device. In order to examine its kinetic effects, we developed an economical pulsed Neutral Beam Injection (NBI) system by using a washer gun plasma source and finally attained the beam power of 0.6 MW (15 kV, 40 A) for its pulse length of 0.5 ms, longer than the FRC lifetime in TS-4. The Monte Carlo simulation indicates that the tangential NB ions of 15 keV are trapped between the magnetic axis and the separatrix. We found that two merging high-s (s is plasma size normalized by ion gyroradius) hydrogen spheromaks with opposite helicities relaxed into the large scale FRC with poloidal flux as high as 15 mWb under the assistance of the NBI. Without the assistance of NBI, however, they did not relax to an FRC but to another spheromak. These facts suggest some ion kinetic effects such as toroidal ion flow are essential to FRC stability. Recently, two new NB sources with acceleration voltage and current of 15 kV and 20 A were installed on the TS-4 device on the midplane for tangential injection, increasing the beam power over 1 MW. We will start the upgraded FRC experiments using the 1 MW NBI for ion flow control.

  10. Machine Protection and Beam Quality during the LHC Injection Process

    CERN Document Server

    Verena Kain, V K

    2005-01-01

    This thesis is concerned with the machine protection system for the LHC injection process, where the intensity of the injected beam is alreay more than one order of magnitude above the equipment damage level. It focuses on a detailed specification, description and performance validation of the protection systems for the transfer from the SPS and the injection into the LHC. Numerical simulations were used to design active (equipment monitoring to ensure correct settings) and passive (collimators and absorbers) protection systems, and to analyze their performance. The simulation methodology was based on two common computer codes: energy deposition simulations were done with FLUKA and particle tracking was done with the tracking module of MAD-X. Realistic machine states were set up for the failure simulations including geometrical and optical mismatch, orbit tolerances, mechanical tolerances, power converter ripples, misalignment of elements and trajectory correction. The equipment damage limit was derived and c...

  11. Beam optics study of a negative ion source for neutral beam injection application at ASIPP

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Jiang-Long; Liang, Li-Zhen [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Jiang, Cai-Chao [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Graduate school, University of Science and Technology of China, Hefei 230026 (China); Xie, Ya-Hong, E-mail: xieyh@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Hu, Chun-Dong; Li, Jun; Gu, Yu-Ming; Chen, Yu-Qian [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Li, Jing-Yong; Wu, Ming-Shan [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Graduate school, University of Science and Technology of China, Hefei 230026 (China)

    2017-04-15

    In order to study the generation and extraction of negative ions for neutral beam injection application, a negative ion source is being designed and constructed at Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP). Through a four electrode grids system inside the accelerator, a negative ion beam will be extracted and accelerated up to −60 kV on a reduced scale extraction area of 12 × 50 cm{sup 2} (the area of PG apertures is 185 cm{sup 2}). The beam optics is a key issue for the accelerator design, and greatly determine the source experimental performance in term of beam current, heat load on the grid, beam divergence, and so on. In this paper, the trajectories of electrons and negative ions were simulated in the electrode grids of the negative ion source. The filter capability of electron deflection magnet on the co-extracted electrons is evaluated and confirmed. The negative ion beam optics was designed according to the calculated results of beam divergence and beam radius along the beamlet in different acceleration voltages. The deflection effect of the electron deflection magnet on the negative ion beam was investigated in the single beamlet case and multi-beamlets case.

  12. An Improved Beam Screen for the LHC Injection Kickers

    CERN Document Server

    Barnes, M J; Ducimetière, L; Garrel, N; Kroyer, T

    2007-01-01

    The two LHC injection kicker magnet systems must produce a kick of 1.3 T.m with a flattop duration variable up to 7860 ns, and rise and fall times of less than 900 ns and 3000 ns, respectively. Each system is composed of two resonant charging power supplies (RCPSs) and four 5 WW transmission line kicker magnets with matched terminating resistors and pulse forming networks (PFNs). A beam screen is placed in the aperture of the magnets: the screen consists of a ceramic tube with conductors on the inner wall. The conductors provide a path for the image current of the, high intensity, LHC beam and screen the ferrite against Wake fields. The conductors initially used gave adequately low beam coupling impedance however inter-conductor discharges occurred during pulsing of the magnet: an alternative design was discharge free at the nominal operating voltage but the impedance was too high for the ultimate LHC beam. This paper presents the results of a new development undertaken to meet the often conflicting requireme...

  13. Imaging instrument for positron emitting heavy ion beam injection

    Energy Technology Data Exchange (ETDEWEB)

    Llacer, J.; Chatterjee, A.; Jackson, H.C.; Lin, J.C.; Zunzunegui, M.V.

    1978-10-01

    The design and performance of an instrument for the imaging of coincidence annihilation gamma rays emitted from the end point of the trajectories of radioactive high-energy heavy ions is described. The positron-emitting heavy ions are the result of nuclear fragmentation of accelerated heavy ions used in cancer therapy or diagnostic medicine. The instrument constructed is capable of locating the ion beam trajectory end point within 1 mm for an injected activity of 200 nanoCi in a measurement time of 1 sec in some favorable conditions. Limited imaging in three dimensions is also demonstrated.

  14. Laboratory Measurements of Electrostatic Solitary Structures Generated by Beam Injection

    International Nuclear Information System (INIS)

    Lefebvre, Bertrand; Chen, Li-Jen; Gekelman, Walter; Pribyl, Patrick; Vincena, Stephen; Kintner, Paul; Pickett, Jolene; Chiang, Franklin; Judy, Jack

    2010-01-01

    Electrostatic solitary structures are generated by injection of a suprathermal electron beam parallel to the magnetic field in a laboratory plasma. Electric microprobes with tips smaller than the Debye length (λ De ) enabled the measurement of positive potential pulses with half-widths 4 to 25λ De and velocities 1 to 3 times the background electron thermal speed. Nonlinear wave packets of similar velocities and scales are also observed, indicating that the two descend from the same mode which is consistent with the electrostatic whistler mode and result from an instability likely to be driven by field-aligned currents.

  15. Imaging instrument for positron emitting heavy ion beam injection

    International Nuclear Information System (INIS)

    Llacer, J.; Chatterjee, A.; Jackson, H.C.; Lin, J.C.; Zunzunegui, M.V.

    1978-10-01

    The design and performance of an instrument for the imaging of coincidence annihilation gamma rays emitted from the end point of the trajectories of radioactive high-energy heavy ions is described. The positron-emitting heavy ions are the result of nuclear fragmentation of accelerated heavy ions used in cancer therapy or diagnostic medicine. The instrument constructed is capable of locating the ion beam trajectory end point within 1 mm for an injected activity of 200 nanoCi in a measurement time of 1 sec in some favorable conditions. Limited imaging in three dimensions is also demonstrated

  16. Steel septum magnets for the LHC beam injection and extraction

    CERN Document Server

    Bidon, S; Guinand, M; Gyr, Marcel; Sassowsky, M; Weisse, E; Weterings, W; Abramov, A; Ivanenko, A I; Kolatcheva, E; Lapyguina, O; Ludmirsky, E; Mishina, N; Podlesny, P; Riabov, A; Tyurin, N

    2002-01-01

    The Large Hadron Collider (LHC) will be a superconducting accelerator and collider to be installed in the existing underground LEP ring tunnel at CERN. It will provide proton-proton collisions with a centre of mass energy of 14 TeV. The proton beams coming from the SPS will be injected into the LHC at 450 GeV by vertically deflecting kicker magnets and horizontally deflecting steel septum magnets (MSI). The proton beams will be dumped from the LHC with the help of two extraction systems comprising horizontally deflecting kicker magnets and vertically deflecting steel septum magnets (MSD). The MSI and MSD septa are laminated iron-dominated magnets using an all welded construction. The yokes are constructed from two different half cores, called coil core and septum core. The septum cores comprise circular holes for the circulating beams. This avoids the need for careful alignment of the usually wedge-shaped septum blades used in classical Lambertson magnets. The MSI and MSD septum magnets were designed and buil...

  17. Active spectroscopy upgrades and neutral beam injection on LTX- β

    Science.gov (United States)

    Elliott, Drew; Biewer, Theodore; Canik, John; Reinke, Matthew; Bell, Ronald; Boyle, Dennis; Guttenfelder, Walter; Kaita, Robert; Kozub, Thomas; Majeski, Richard; Merino, Enrique

    2017-10-01

    The LTX- β upgrade includes the addition of neutral beam injection (NBI) and increased active spectroscopy. Typical plasmas have been and are expected to remain inboard limited, at 14 cm with minor radii of 18-23 cm. The NBI, 35 Amps of 20 keV particles, will enable active diagnosis of ion velocity distribution profiles through charge exchange (CHERS). 18 CHERS views will cover more than a full minor radius, each sampling 2 cm of major radius. The system has both a set of beam directed ``active'' views and a symmetric set of views pointing away from the beam for stray light subtraction. Along with measuring ion temperatures and impurity transport, the CHERS diagnostic will measure the plasma rotation profiles. The recently described low recycling regime is predicted to allow for high rotational velocities due to the low neutral drag. The planned NBI has been predicted to give on axis velocities near 100 km/s. Flow shear is expected to increase confinement in this regime by suppressing trapped electron mode and other microturbulence enhanced transport. Upgrades to the Thomson scattering system, including an array of polychromators and a new camera, will assist in diagnosing the low density hot edge in this low recycling regime. Supported by US DOE contracts DE-AC02-09CH11466 and DE-AC05-00OR22725.

  18. Electric potential structures and propagation of electron beams injected from a spacecraft into a plasma

    Science.gov (United States)

    Singh, Nagendra; Hwang, K. S.

    1988-01-01

    One-dimensional Vlasov simulations are used to study the propagation of electron beams injected from a spacecraft into an ambient plasma and the associated potential structures. It is shown that, for a given beam velocity, the propagation velocity and the potential structure depends on the beam density. In the case of moderate beams, a double layer forms near the beam head which propagates into the ambient plasma much more slowly than the initial beam velocity.

  19. Metal impurity injection into DIVA plasmas with a Q-switched laser beam

    International Nuclear Information System (INIS)

    Yamauchi, Toshihiko; Nagami, Masayuki; Sengoku, Seio; Kumagai, Katsuaki

    1978-08-01

    Metal impurity injection into DIVA plasmas with a Q-switched ruby laser beam is described. Metal materials used are aluminium and gold. The Q-switched laser beam is incident onto a thin metal film thickness about 0.2 μm coated on pyrex glass plate surface. The metal film is vaporized by the laser beam and injected into DIVA plasma. The laser-beam injection method has advantages of sharp profile of vaporized metal, easy control of vaporized metal quantity and injection rate control of metal vapor. (author)

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

    International Nuclear Information System (INIS)

    Bykovskij, V.F.; Meshkov, I.N.; Seleznev, I.A.; Syresin, E.M.

    2003-01-01

    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

  1. Confinement studies during neutral beam injection in PLT

    International Nuclear Information System (INIS)

    Goldston, R.; Davis, S.; Eubank, H.

    1980-12-01

    Neutral beam injection experiments on PLT have provided definitive information on ion energy confinement in highly collisionless plasmas. We find that ion thermal conduction is consistent, within a factor of approx. 3, with neoclassical theory, and that anomalous thermal convection of ion energy is a factor of 2-3 less than would be calculated from the INTOR D/sub e/ with a convection loss term of the form 5/2nkTv/sub r/. From our experiments with a shunted TF coil we have found that a single shallow ripple well of 2.5% has a neglible effect on ion energy confinement, even at the lowest collisionality obtainable on PLT. Scrutiny of the analytic theories of ripple induced transport motivated by these experiments, suggests that more theoretical (and perhaps numerical) work is needed in this area

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

    International Nuclear Information System (INIS)

    Petzoldt, R.W.

    1995-01-01

    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 2 if the fuel temperature is less than 17 K. A 0.1 μm thick dual membrane will allow nearly 2,000 m/s 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

  3. Beam-plasma interaction in case of injection of the electron beam to the symmetrically open plasma system

    International Nuclear Information System (INIS)

    Opanasenko, A.V.; Romanyuk, L.I.

    1992-01-01

    A beam-plasma interaction at the entrance of the symmetrically open plasma system with an electron beam injected through it is investigated. An ignition of the plasma-beam discharge on waves of upper hybrid dispersion branch of a magnetoactive plasma is found in the plasma penetrating into the vacuum contrary to the beam. It is shown that the beam-plasma discharge is localized in the inhomogeneous penetrating plasma in the zone where only these waves exist. Regularities of the beam-plasma discharge ignition and manifestation are described. It is determined that the electron beam crossing the discharge zone leads to the strong energy relaxation of the beam. It is shown possible to control the beam-plasma discharge ignition by changing the potential of the electron beam collector. (author)

  4. 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.

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

    Science.gov (United States)

    Douglas, David R [York County, VA

    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.

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

    International Nuclear Information System (INIS)

    Gardner, C.; Ahrens, L.; Williams, N.

    1999-01-01

    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

  7. Optimizing density down-ramp injection for beam-driven plasma wakefield accelerators

    Science.gov (United States)

    Martinez de la Ossa, A.; Hu, Z.; Streeter, M. J. V.; Mehrling, T. J.; Kononenko, O.; Sheeran, B.; Osterhoff, J.

    2017-09-01

    Density down-ramp (DDR) injection is a promising concept in beam-driven plasma wakefield accelerators for the generation of high-quality witness beams. We review and complement the theoretical principles of the method and employ particle-in-cell (PIC) simulations in order to determine constrains on the geometry of the density ramp and the current of the drive beam, regarding the applicability of DDR injection. Furthermore, PIC simulations are utilized to find optimized conditions for the production of high-quality beams. We find and explain the intriguing result that the injection of an increased charge by means of a steepened ramp favors the generation of beams with lower emittance. Exploiting this fact enables the production of beams with high charge (˜140 pC ), low normalized emittance (˜200 nm ) and low uncorrelated energy spread (0.3%) in sufficiently steep ramps even for drive beams with moderate peak current (˜2.5 kA ).

  8. Studies of the Injection System in the Decay Ring of Beta-Beam Neutrino Souce Project

    CERN Document Server

    Payet, Jacques

    2005-01-01

    After being accelerated the beta radioactive ions are accumulated in a decay ring. The losses due to their decay are compensated with regular injections in presence of filled bucket. Without a damping mechanism, the new particles are injected at a different energy from the stored beam energy, then the old and the new buckets are merged with RF manipulation. This type of injection has to be done, in a dispersive region, in presence of closed orbit bump and a septum magnet. The sizes of the injected beam and of the stored beam have to be adjusted in order to minimize the losses on the septum and to maximize the stored intensity keeping small beam sizes. The dispersion has to be large enough in order to decrease the energy difference. The injection system may be located either in the arc or in a straight section, both possibilities have been studied.

  9. 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.

  10. Cross-field injection of a charged, polarized, ion-electron beam

    International Nuclear Information System (INIS)

    Hamilton, G.W.

    1976-01-01

    An early idea for fueling a controlled fusion device had been the injection of a polarized mixture of ions and electrons across a magnetic field and into the device. Now, the beam intensity (several kA/cm 2 ) required for this technique is available from pulsed ion diodes. Remaining feasibility questions involve beam optics and trapping. The most obvious advantage over neutral-beam injection is avoidance of the need to produce high-energy atoms. Therefore, the technique will compete best at ion energies above 100 keV. The method appears feasible for pulsed startup of mirror machines, but not for steady-state injection into a plasma

  11. Evaluation of the Beam Coupling Impedance of New Beam Screen Designs for the LHC Injection Kicker Magnets

    CERN Document Server

    Day, H; Caspers, F; Jones, R M; Salvant, B; Métral, E

    2013-01-01

    The LHC injection kicker magnets (MKIs) have experienced a significant degree of beam induced heating since the beginning of 2011 due to the increasing intensity stored in the LHC, for long periods of time, and the relatively large broadband beam coupling impedance of the installed kicker magnets. In this paper we show the sources of impedance in the MKIs, and the effect that the beam screen dimensions have on the impedance. We show how these alter the power loss, and present an improved beam screen design that improves shielding on the magnet, whilst further improving the electrical breakdown situation.

  12. Design of kicker magnet and power supply unit for synchrotron beam injection

    International Nuclear Information System (INIS)

    Wang, Ju.

    1991-03-01

    To inject beams from the positron accumulator ring (PAR) into the synchrotron, a pulsed kicker magnet is used. The specifications of this kicker magnet and the power supply unit are listed and discussed in this report

  13. Analysis of particle species evolution in neutral beam injection lines

    International Nuclear Information System (INIS)

    Kim, J.; Haselton, H.H.

    1978-07-01

    Analytic solutions to the rate equations describing the species evolution of a multispecies positive ion beam of hydrogen due to charge exchange and molecular dissociation are derived as a function of the background gas (H 2 ) line density in the neutralizing gas cell and in the drift tube. Using the solutions, calculations are presented for the relative abundance of each species as a function of the gas cell thickness, the reionization loss rates in the drift tube, and the neutral beam power as a function of the beam energy and the species composition of the original ion beam

  14. 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.

  15. Tokamak Fusion Test Reactor neutral beam injection system vacuum chamber

    International Nuclear Information System (INIS)

    Pedrotti, L.R.

    1977-01-01

    Most of the components of the Neutral Beam Lines of the Tokamak Fusion Test Reactor (TFTR) will be enclosed in a 50 cubic meter box-shaped vacuum chamber. The chamber will have a number of unorthodox features to accomodate both neutral beam and TFTR requirements. The design constraints, and the resulting chamber design, are presented

  16. 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.

  17. Transient phenomena during electron beam injection in the Saclay 45 MeV accelerator

    International Nuclear Information System (INIS)

    Marcou, J.; Papiernik, A.; Wartski, L.; Bolore, M.; Filippi, G.; Roland, S.

    1969-01-01

    The principal features of transient phenomena, when electron beams are injected in a constant field linear accelerator, are analysed and interpreted by the use of a simple theory. Influence of these transient phenomena on the energy of accelerated particles is observed using a relatively precise method. For very large beam currents, non linear phenomena due to beam deformation can be exhibited, when the electron velocity is not exactly equal to the light velocity. (author) [fr

  18. Heating efficiency of high-power perpendicular neutral-beam injection in PDX

    International Nuclear Information System (INIS)

    Hawryluk, R.J.; Arunasalam, V.; Bell, M.

    1982-03-01

    The heating efficiency of high power (up to 7.2 MW) near-perpendicular neutral beam injection in the PDX tokamak is comparable to that of tangential injection in PLT. Collisionless plasmas with central ion temperatures up to 6.5 keV and central electron temperatures greater than 2.5 keV have been obtained. The plasma pressure, including the contribution from the beam particles, increases with increasing beam power and does not appear to saturate, although the parametric dependence of the energy confinement time is different from that observed in ohmic discharges

  19. Noise Studies on Injected-Beam Crossed-Field Devices.

    Science.gov (United States)

    1980-11-01

    numerous experimental and theoretical studies. A large contribution to the understanding was made I by Van Duzer , Whinnery, and co-workers of the...Conference, Amsterdam, Netherlands, pp. 8-31, 1970. 10. T. Van Duzer , J. Whinnery, "Noise in Electron Beams", Crossed-Field Microwave Devices (E. Okress, ed

  20. Experimental study of the dependence of beam current on injection ...

    Indian Academy of Sciences (India)

    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 ...

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

    International Nuclear Information System (INIS)

    Xiang, W.; Spaedtke, P.; Hollinger, R.; Galonska, M.; Heymach, F.

    2004-07-01

    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.)

  2. Optimizing density down-ramp injection for beam-driven plasma wakefield accelerators

    Directory of Open Access Journals (Sweden)

    A. Martinez de la Ossa

    2017-09-01

    Full Text Available Density down-ramp (DDR injection is a promising concept in beam-driven plasma wakefield accelerators for the generation of high-quality witness beams. We review and complement the theoretical principles of the method and employ particle-in-cell (PIC simulations in order to determine constrains on the geometry of the density ramp and the current of the drive beam, regarding the applicability of DDR injection. Furthermore, PIC simulations are utilized to find optimized conditions for the production of high-quality beams. We find and explain the intriguing result that the injection of an increased charge by means of a steepened ramp favors the generation of beams with lower emittance. Exploiting this fact enables the production of beams with high charge (∼140  pC, low normalized emittance (∼200  nm and low uncorrelated energy spread (0.3% in sufficiently steep ramps even for drive beams with moderate peak current (∼2.5  kA.

  3. A very sensitive nonintercepting beam average velocity monitoring system for the TRIUMF 300-keV injection line

    International Nuclear Information System (INIS)

    Yin, Y.; Laxdal, R.E.; Zelenski, A.; Ostroumov, P.

    1997-01-01

    A nonintercepting beam velocity monitoring system has been installed in the 300-keV injection line of the TRIUMF cyclotron to reproduce the injection energy for beam from different ion sources and to monitor any beam energy fluctuations. By using a programmable beam signal leveling method the system can work with a beam current dynamic range of 50 dB. Using synchronous detection, the system can detect 0.5 eV peak-to-peak energy modulation of the beam, sensitivity is 1.7x10 -6 . The paper will describe the principle and beam measurement results. copyright 1997 American Institute of Physics

  4. Numerical simulation of plasma of large-dimensions produced by injecting electron beam into air

    International Nuclear Information System (INIS)

    Li Hong; Su Tie; Ouyang Liang; Wang Huihui; Bai Xiaoyan; Chen Zhipeng; Liu Wandong

    2006-01-01

    A four-species 1-D hybrid numerical model was set up to simulate the process of formation of large-dimension plasma produced by injecting electron beams into air. It showed that plasma of the order of 0.5 m in length and 10 12 cm -3 in density can be produced by an electron beam with the energy of 140 keV and flux of 50 mA/cm 2 . The effect of space charge associated with the beam on the beam propagation and related process vanishes soon after the plasma is produced. The beam flux is directly relevant to the plasma density, but the beam energy affects both the dimensions and the density of produced plasma. (authors)

  5. Relativistic electron-beam generation in plasma-filled diode and foilless injection into dense plasma

    Science.gov (United States)

    Burmasov, V. S.; Kandaurov, I. V.; Kruglyakov, E. P.; Meshkov, O. I.

    1994-05-01

    The traditional way of relativistic electron beam (REB) injection in the experiments on REB- plasma interaction is the injection through an anode foil that separates vacuum diode from plasma chamber. The presence of separating foil leads to the following: (1) replacement of destroyed foil is required after each shot, and (2) the beam angular characteristics making worse. A beam with low angular spread can be obtained from foilless diode placed into strong guiding magnetic field; the problem is how to avoid the diode shortening in the presence of a dense plasma from the interaction chamber. In the experiments on studying of Langmuir turbulence, carrying out on GOL-M device it becomes possible to avoid a separating foil and to obtain a foilless injection of REB into a dense (

  6. Picosecond stability of injection of parallel high-current pulsed electron beams

    Science.gov (United States)

    Yalandin, M. I.; Reutova, A. G.; Ul'Maskulov, M. R.; Sharypov, K. A.; Shpak, V. G.; Shunailov, S. A.; Klimov, A. I.; Rostov, V. V.; Mesyats, G. A.

    2009-09-01

    The stability of operation of parallel explosive-emission cathodes driven by a split high-voltage pulse with a subnanosecond leading front has been studied. It is established that, upon the training of graphite cathodes in vacuum with up to ˜104 pulses, the current pulse fronts of injected high-current electron beams exhibit a mutual temporal dispersion not exceeding ten picoseconds. The dynamics of this parameter during the training stage, the variation of the absolute spread, and the growth of a relative delay of the moments of beam injection have been investigated.

  7. Design features and operational characteristics of the PEP beam-transport and injection system

    International Nuclear Information System (INIS)

    Peterson, J.M.; Brown, K.L.; Truher, J.B.

    1981-03-01

    The PEP beam-transport system was designed to transmit 4-to-15 GeV electron and positron beams from the SLAC linac within a +- 0.8% momentum band, to have flexible tuning of the betatron and off-momentum functions for matching into the PEP storage ring, and to have convenient operating characteristics. The transport lines were brought into operation quickly and have operated well. Electron injection has been consistent and efficient and relatively easy to accomplish. Positron injection also has been satisfactory but is variable and more sensitive to ring conditions

  8. Large area ion source for neutral beam injection

    International Nuclear Information System (INIS)

    Bottiglioni, F.; Bussac, J.P.; Desmons, M.; Fumelli, M.

    1983-01-01

    JET standard neutral beam injectors require an extraction area of 45 x 18 cm 2 . A plasma source suited to such a large dimension has been constructed and operated a few months on a test stand, prior to its mounting on the PINI now under test at FAR. This source is a rectangular Periplasmatron strongly cooled for 10 s pulses. So far, pulses of 2 s at 800 A and 110 V have been obtained. The nominal ion current density of 200 mA/cm 2 has been achieved, with an overall plasma uniformity better than +- 6%. (author)

  9. Crystal Collimation with Lead Ion Beams at Injection Energy in the LHC

    CERN Document Server

    Rossi, Roberto; Andreassen, Arvid; Butcher, Mark; Dionisio Barreto, Cristovao Andre; Masi, Alessandro; Mirarchi, Daniele; Montesano, Simone; Lamas Garcia, Inigo; Redaelli, Stefano; Scandale, Walter; Serrano Galvez, Pablo; Rijllart, Adriaan; Valentino, Gianluca; Galluccio, Francesca; CERN. Geneva. ATS Department

    2015-01-01

    During this MD, performed on December 2nd 2015, bent silicon crystals were tested with ion beams for a possible usage of crystal-assisted collimation. Tests were performed at injection energy, using both horizontal and vertical crystals. Ion channeling was observed for the first time with LHC beams at the record energy of 450 GeV 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.

  10. An elegant impulser developed for flat beam injection

    International Nuclear Information System (INIS)

    Wilson, M.J.; Goerz, D.A.; Speer, R.D.

    1998-01-01

    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

  11. Design of neutral beam injection power supplies for ITER

    International Nuclear Information System (INIS)

    Watanabe, Kazuhiro; Okumura, Yoshikazu; Ono, Youichi; Tanaka, Masanobu

    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)

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

    International Nuclear Information System (INIS)

    Pitcher, C.S.; Budny, R.V.; Hill, K.W.; Kilpatrick, S.J.; Manos, D.M.; Medley, S.S.; Ramsey, A.T.

    1991-05-01

    Detailed boundary plasma measurements on TFTR have been made during a NBI power scan in the range P tot = 1MW--20MW in the L-mode regime. The behavior of the plasma density left-angle n e right-angle, radiated power P rad , carbon and deuterium fluxes Γ C , Γ D , and Ζ eff can be summarized as, left-angle n e right-angle ∝ P tot 1/2 , P rad , Γ C , Γ D ∝ P tot , and Ζ eff ∼ 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

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

    International Nuclear Information System (INIS)

    Gradic, D.; Dinklage, A.; Brakel, R.; McNeely, P.; Rust, N.; Wolf, R.; Osakabe, M.

    2015-01-01

    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)

  14. Experience of direct percutaneous sac injection in type II endoleak using cone beam computed tomography.

    Science.gov (United States)

    Park, Yoong-Seok; Do, Young Soo; Park, Hong Suk; Park, Kwang Bo; Kim, Dong-Ik

    2015-04-01

    Cone beam CT, usually used in dental area, could easily obtain 3-dimensional images using cone beam shaped ionized radiation. Cone beam CT is very useful for direct percutaneous sac injection (DPSI) which needs very precise measurement to avoid puncture of inferior vena cava or vessel around sac or stent graft. Here we describe two cases of DPSI using cone beam CT. In case 1, a 79-year-old male had widening of preexisted type II endoleak after endovascular aneurysm repair (EVAR). However, transarterial embolization failed due to tortuous collateral branches of lumbar arteries. In case 2, a 72-year-old female had symptomatic sac enlargement by type II endoleak after EVAR. However, there was no route to approach the lumbar arteries. Therefore, we performed DPSI assisted by cone beam CT in cases 1, 2. Six-month CT follow-up revealed no sign of sac enlargement by type II endoleak.

  15. 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.

  16. Particle and momentum confinement in tokamak plasmas with unbalanced neutral beam injection and strong rotation

    International Nuclear Information System (INIS)

    Malik, M.A.

    1988-01-01

    There is a self-consistent theory of the effects of neutral beam injection on impurity transport in tokamak plasmas. The theory predicts that co-injection drives impurities outward and that counter-injection enhances the normally inward flow of impurities. The theory was applied to carry out a detailed analysis of the large experimental database from the PLT and the ISX-B tokamaks. The theory was found to generally model the experimental data quite well. It is, therefore, concluded that neutral beam co-injection can drive impurities outward to achieve clean central plasmas and a cool radiating edge. Theoretical predictions for future thermonuclear reactors such as INTOR, TIBER II, and ITER indicated that neutral beam driven flow reversal might be an effective impurity control method if the rate of beam momentum deposited per plasma ion is adequate. The external momentum drag, which is a pivotal concept in impurity flow reversal theory, is correctly predicted by the gyroviscous theory of momentum confinement. The theory was applied to analyze experimental data from the PLT and the PDX tokamaks with exact experimental conditions. The theory was found to be in excellent agreement with experiment over a wide range of parameters. It is, therefore, possible to formulate the impurity transport theory from first principles, without resort to empiricism

  17. Thermal analysis of injection beam dump of high-intensity rapid-cycling synchrotron in J-PARC

    Science.gov (United States)

    Kamiya, J.; Saha, P. K.; Yamamoto, K.; Kinsho, M.; Nihei, T.

    2017-10-01

    The beam dump at the beam injection area in the J-PARC 3-GeV rapid cycling synchrotron (RCS) accepts beams that pass through the charge exchange foil without ideal electron stripping during the multi-turn beam injection. The injection beam dump consists of the beam pipe, beam stopper, radiation shield, and cooling mechanism. The ideal beam power into the injection beam dump is 400 W in the case of design RCS extraction beam power of 1 MW with a healthy foil, which has 99.7 % charge stripping efficiency. On the other hand, as a radiation generator, the RCS is permitted to be operated with maximum average beam power of 4 kW into the injection beam dump based on the radiation shielding calculation, in consideration of lower charge stripping efficiency due to the foil deterioration. In this research, to evaluate the health of the RCS injection beam dump system from the perspective of the heat generation, a thermal analysis was performed based on the actual configuration with sufficiently large region, including the surrounding concrete and soil. The calculated temperature and heat flux density distribution showed the validity of the mesh spacing and model range. The calculation result showed that the dumped 4 kW beam causes the temperature to increase up to 330, 400, and 140 °C at the beam pipe, beam stopper, and radiation shield, respectively. Although these high temperatures induce stress in the constituent materials, the calculated stress values were lower than the ultimate tensile strength of each material. Transient temperature analysis of the beam stopper, which simulated the sudden break of the charge stripper foil, demonstrated that one bunched beam pulse with the maximum beam power does not lead to a serious rise in the temperature of the beam stopper. Furthermore, from the measured outgassing rate of stainless steel at high temperature, the rise in beam line pressure due to additive outgassing from the heated beam pipe was estimated to have a negligible

  18. Computational studies of impurity effects, impurity control, and neutral beam injection in large tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Post, D.E.; Goldston, R.J.; Grimm, R.C.

    1978-09-01

    Computational models have been constructed for the Princeton Large Torus (PLT), the Poloidal Divertor Experiment (PDX), and the Tokamak Fusion Test Reactor (TFTR). These models have been calibrated by comparison with current experiments and used to predict plasma parameters and delineate favorable modes of operation for future experiments. The models for PLT emphasize plasma transport and neutral beam injection heating. The models for PDX emphasize the capability of divertors for impurity and recycling control in intense neutral-beam-heated tokamaks, as well as optimization of the MHD properties of divertor-equipped tokamaks. The TFTR calculations stress the fusion aspects of a large, circular cross-section D-T tokamak with intense neutral beam injection.

  19. Neutral-beam injection experiments in the ISX-B tokamak

    International Nuclear Information System (INIS)

    Murakami, M.; Swain, D.W.; Bates, S.C.

    1981-01-01

    Injection of H 0 into D + plasmas with beam power Psub(b) of up to 1.7 MW has produced root-mean-square betas of approximately 4%, volume-averaged betas of approximately 3%, and central betas of approximately 10% in the ISX-B tokamak. Although theoretical calculations indicate that the observed equilibria may be unstable to ballooning modes, no catastrophic loss of confinement has been observed, and beta continues to increase with injection power. In these beam-dominated high-beta discharges the electron and ion energy confinement times are still similar to those obtained with Ohmic heating: ion energy confinement is neoclassical within a factor of about two, and electron energy confinement follows the usual Alcator scaling. In high-power injection discharges, the character of the magnetohydrodynamic (MHD) behaviour changes, the particle confinement time decreases, and the inward impurity transport appears to be inhibited. These effects, however, may not be linked directly to beta. (author)

  20. Test beam results of a heavily irradiated Current Injected Detector (CID)

    CERN Document Server

    Harkonen, J; Tuominen, E; Moilanen, H; Maenpaa, T; Verbitskaya, E; Eremin, V; Czellar, S; Dierlamm, A; Tuovinen, E; Lampen, T; Frey, M; Li, Z; Luukka, P

    2010-01-01

    A heavily irradiated (3 x 10(15) 1 MeV n(eq)/cm(2)) Current Injected Detector (CID) was tested with 225 GeV muon beam at CERN H2 beam line. In the CID concept the current is limited by the space charge. The injected carriers will be trapped by the deep levels and this induces a stable electric field through the entire bulk regardless of the irradiation fluence the detector has been exposed to. The steady-state density of the trapped charge is defined by the balance between the trapping and the emission rates of charge carriers (detrapping). Thus, the amount of charge injection needed for the electric field stabilization depends on the temperature. AC-coupled 16 cm(2) detector was processed on high resistivity n-type magnetic Czochralski silicon, and it had 768 strips, 50 mu m pitch, 10 mu m strip width and 3.9 cm strip length. The beam test was carried out using a silicon beam telescope that is based on the CMS detector readout prototype components, APV25 readout chips, and eight strip sensors made by Hamamat...

  1. Impurity levels and power loading in the PDX tokamak with high power neutral beam injection

    Energy Technology Data Exchange (ETDEWEB)

    Fonck, R.J.; Bell, M.; Bol, K.

    1982-10-01

    The PDX tokamak provides an experimental facility for the direct comparison of various impurity control techniques under reactor-like conditions. Four neutral beam lines can inject up to 6 MW for 300 ms. Carbon rail limiter discharges have been used to test the effectiveness of perpendicular injection, but non-disruptive full power operation for > 100 ms is difficult without extensive conditioning. Initial tests of a toroidal bumper limiter indicate reduced power loading and roughly similar impurity levels compared to the carbon rail limiter discharges. Poloidal divertor discharges with up to 5 MW of injected power are cleaner than similar circular discharges, and the power is deposited in a remote divertor chamber. High density divertor operation indicates a reduction of impurity flow velocity in the divertor and enhanced recycling in the divertor region during neutral injection.

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

    Science.gov (United States)

    Nicolosi, Dario; Cosentino, Luigi; Mascali, David; Pappalardo, Alfio; Castro, Maurizio; Celona, Luigi; Marchetta, Carmelo; Marletta, Salvatore; Maugeri, Antonio; Rifuggiato, Danilo; Seminara, Angelo; Gammino, Santo

    2016-02-01

    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 BaF2 layer evaporated on an aluminium plate, has been tested by using 20Ne and 40Ar 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.

  3. 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.

  4. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Bhat, C. M. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    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.

  6. Beam Induced Ferrite Heating of the LHC Injection Kickers and Proposals for Improved Cooling

    CERN Document Server

    Barnes, M J; Calatroni, S; Day, H; Ducimetière, L; Garlaschè, M; Gomes Namora, V; Mertens, V; Sobiech, Z; Taborelli, M; Uythoven, J; Weterings, W

    2013-01-01

    The two LHC injection kicker systems produce an integrated field strength of 1.3 T·m with a flattop duration variable up to 7860 ns, and rise and fall times of less than 900 ns and 3000 ns, respectively. A beam screen is placed in the aperture of each magnet, which consists of a ceramic tube with conductors in the inner wall. The conductors provide a path for the beam image current and screen the ferrite yoke against wakefields. Recent LHC operation, with high intensity beam stable for many hours, resulted in significant heating of both the ferrite yoke and beam impedance reduction ferrites. For one kicker magnet the ferrite yoke approached its Curie temperature. As a result of a long thermal time-constant the ferrite yoke can require several hours to cool sufficiently to allow re-injection of beam, thus limiting the running efficiency of the LHC. Thermal measurement data has been analysed, a thermal model developed and emissivity measurements carried out. Various measures to improve the ferrite cooling have...

  7. Plasma behavior with molecular beam injection in the HL-1m tokamak

    International Nuclear Information System (INIS)

    Yao Lianghua; Tang Nianyi; Cui Zhengying; Xu Deming; Deng Zhongchao; Ding Xuantong; Luo Junlin; Dong Jiafu; Guo Gancheng; Yang Shikun; Cui Chenghe; Xiao Zhenggui; Liu Dequan; Chen Xiaoping; Yan Longwen; Yan Donghai; Wang Enyao; Deng Xiwen

    1999-01-01

    The authors report effect of the new fueling method of high speed molecular beam injection on Tokamak confinement improvement. The present method is an improvement of conventional gas puffing, with performance comparable to the small pellet injection in HL-1M and also to the slow pellet in ASDEX. The fact that a shallower fueling can lead to similar confinement improvement as a deep one suggests that there may exist a critical position in a Tokamak plasma such that any kind of fueling will have a better confinement as long as it can give rise to density peaking at the critical position

  8. FLOC: Field Line and Orbit Code for the study of ripple beam injection into tokamaks

    International Nuclear Information System (INIS)

    Fowler, R.H.; Lee, D.K.; Gaffney, P.W.; Rome, J.A.

    1978-06-01

    The computer code described is used to study ripple beam injection into a tokamak plasma. The collisionless guiding center equations of motion are integrated to find the orbits of single particles in realistic magnetic fields for ripple injection. In order to determine if the ripple is detrimental to the plasma, the magnetic flux surfaces are constructed by integration of the field line equations. The numerical techniques are described, and use of the code is outlined. A program listing is provided, and the results of sample cases are presented

  9. Fusion reactivities and neutron source characteristics of beam-driven toroidal reactors with both D and T injection

    International Nuclear Information System (INIS)

    Jassby, D.L.; Towner, H.H.

    1976-01-01

    The reactor performance is considered for intensely beam-driven tokamak plasmas with 50:50 D-T composition maintained by neutral-beam injection of both D and T, together with plasma recycling. The D and T are injected with equal intensity and velocity. This mode of operation is most appropriate for high-duty-factor, high-power-density operation, in the absence of pellet injection. The isotropic velocity distributions of energetic D and T ions (for multi-angle injection) are calculated from a simple slowing-down model, but include a tail above the injection velocity. The neutron source characteristics are determined from fusion reactivities calculated for beam-target, hot-ion, and thermonuclear reactions. For conditions where Q approximates 1, beam-target reactions are dominant, although reactions among the hot ions contribute substantially to P/sub fusion/ when n/sub hot//n /sub e/ greater than or equal to 0.2

  10. Low frequency electrostatic instabilities excited by injection of an electron beam in space

    International Nuclear Information System (INIS)

    Hwang, Y.S.; Okuda, H.

    1989-02-01

    One-dimensional particle simulations have been carried out to study the low frequency broadband electrostatic noise that propagates almost perpendicularly from the magnetic field line when a nonrelativistic electron beam is injected into space from a spacecraft. For T/sub e/ = T/sub i/ the electrostatic ion cyclotron waves appear as well as the waves near the lower hybrid frequency. When the magnetic field is reduced so that Ω/sub e/ T/sub i/, oblique ion acoustic instabilities appear to propagate almost perpendicular to the magnetic field. In addition, a very low frequency mode at ω << Ω/sub i/ is found to be generated by the electrons flowing into the conductor. Both the ion injected beam electrons as well as the ambient electrons flowing into the spacecraft are responsible for generating those instabilities, which accelerate ions perpendicular to the magnetic field. 11 refs., 9 figs

  11. Focusing and bunching of ion beam in axial injection channel of IPHC cyclotron TR24

    Science.gov (United States)

    Adam, T.; Ivanenko, I.; Kazarinov, N.; Osswald, F.; Traykov, E.

    2017-07-01

    The CYRCe cyclotron (CYclotron pour la ReCherche et l’Enseignement) is used at IPHC (Institut Pluridisciplinaire Hubert Curien) for the production of radio-isotopes for diagnostics, medical treatments and fundamental research in radiobiology. The TR24 cyclotron produced and commercialized by ACSI (Canada) delivers a 16-25 MeV proton beam with intensity from few nA up to 500 μA. The solenoidal focusing instead of existing quadrupole one is proposed in this report. The changing of the focusing elements will give the better beam matching with the acceptance of the spiral inflector of the cyclotron. The parameters of the focusing solenoid are found. Additionally, the main parameters of the bunching system are evaluated in the presence of the beam space charge. This system consists of the buncher installed in the axial injection beam line of the cyclotron. The using of the grid-less multi harmonic buncher may increase the accelerated beam current and will give the opportunity to new proton beam applications.

  12. Calculation of beam injection and modes of acceleration for the JINR phasotron

    International Nuclear Information System (INIS)

    Vorozhtsov, S.B.; Dmitrievsky, V.P.

    1981-01-01

    On the basis of computer simulation of particles motion from the injection region up to the final radius of the accelerated proton beam behaviour together with different modes of the JINR high current synchrocyclotron operation is investigated. The THOUR modified computer code is used for calculations. The calculations have been performed with allowance for particle radial-phase motion and particle axial motion and although with beam collective effects. Beam dynamics during first turns of particles has been considered by integrating equations of motion. Tolerances for magnetic field structure in the region of first phase oscillation are obtained. Verifications of time dependences of accelerated voltage amplitude are performed. Time dependences of beam intensity (with and without account for space charge effect) and of mean magnetic field disturbance and the dependence of the separatrice dimension on the orbit radius of the accelerated beam are given. The conclusion is drawn on the correctness of the earlier appreciation of beam intensity equaling 40-45 mkA

  13. Beam shaping diffuser based fiber injection for increasing stability of industrial robotic laser applications

    Science.gov (United States)

    Lizotte, Todd E.; Dickey, Fred M.

    2013-09-01

    This paper documents the investigation of a diffuser based fiber injection system and its successful implementation and experimental testing in a robotic industrial process. This is a new concept based on the idea that a diffuser that has the angular radiation pattern matching the NA of the fiber can be used to approximate the field pattern at the face of a mode filled fiber. The research considered two approaches to this problem. The two related approaches to the problem were developed conceptually and analytically for two predominant wavelengths of interest, 1030 nm and 532 nm. The first is an implementation that would consist of illuminating the diffuser with a uniform spot having the same shape as the fiber core and imaging the illuminated spot onto the fiber face. The other approach is the use of a far-field (Fourier transform) diffractive element with a transform lens. This paper will provide an overview of the analytics and testing of the later concept (Fourier transform) and the experimental implementation of the design to a laser fiber coupling system to launch a 532 nm pulsed laser beam into a square core fiber optical beam delivery system. Further detail will be shared with the experimental performance of the design when integrated within a multi-axis robotic arm, which has six degrees of freedom. These results will include how the fiber injection system improved laser beam stability during process operations, in comparison to traditional simple lens injection methods.

  14. Mode and sawtooth behaviour during neutral beam injection in the W VII-A stellarator

    International Nuclear Information System (INIS)

    Grieger, G.; Renner, H.; Sapper, J.; Wobig, H.; Dorst, D.; Cattanei, G.; Javel, P.; Rau, F.; Zippe, M.; Jaeckel, H.

    1980-02-01

    The mode behaviour during Neutral Beam Injection in the WENDELSTEIN VII-A stellarator is presented. The analysis is mainly relying on soft X-ray measurements. Two types of discharges were found during Neutral Beam Injection with plasma currents >= 20 kA. The first type is dominated by large, regular and long sawteeth, which are caused by a (m,n) = (1,1) mode. In the second type the sawteeth disappear completely. Later in the discharge a local disruption causes a transition to the first type; this disruption has a (3,2) mode precursor. A new mode (2,2) is found and phase coupled to the (3,2) mode. Even at a high external rotational transform (t 0 = 0.23) a large (2,1) mode is found after the (3,2) mode has caused the local disruption. At slightly lower external rotational transform values major current disruptions may even occur. This is mainly due to the enhanced edge heating by the Neutral Beam Injection. Results of simulations of the mode structures are also presendet. (orig./GG)

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

    International Nuclear Information System (INIS)

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

    1999-01-01

    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

  16. Reduction of Surface Flashover of the Beam Screen of the LHC Injection Kickers

    CERN Document Server

    Barnes, M J; Calatroni, S; Caspers, F; Ducimetière, L; Gomes Namora, V; Mertens, V; Noulibos, R; Taborelli, M; Teissandier, B; Uythoven, J; Weterings, W

    2013-01-01

    The LHC injection kicker magnets include beam screens to shield the ferrite yokes against wake fields resulting from the high intensity beam. The screening is provided by conductors lodged in the inner wall of a ceramic support tube. LHC operation with increasingly higher bunch intensity and short bunch lengths, requires improved ferrite screening. This will be implemented by additional conductors; however these must not compromise the good high-voltage behaviour of the kicker magnets. Extensive studies have been carried out to better satisfy the often conflicting requirements for low beam coupling impedance, fast magnetic field rise-time, ultra-high vacuum and good high voltage behaviour. A new design is proposed which significantly reduces the electric field associated with the screen conductors. Results of high voltage tests are also presented.

  17. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Andreev, V. V., E-mail: temple18@mail.ru; Novitsky, A. A.; Vinnichenko, L. A.; Umnov, A. M.; Ndong, D. O. [Peoples’ Friendship University of Russia (Russian Federation)

    2016-03-15

    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.

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

    International Nuclear Information System (INIS)

    Johnson, D.; Bell, M.; Bitter, M.

    1983-01-01

    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)

  20. Power deposition by neutral beam injected fast ions in field-reversed configurations

    International Nuclear Information System (INIS)

    Takahashi, Toshiki; Kato, Takayuki; Kondoh, Yoshiomi; Iwasawa, Naotaka

    2004-01-01

    The effects of Coulomb collisions on neutral beam (NB) injected fast ions into field-reversed configuration (FRC) plasmas are investigated by calculating the single particle orbits, where the ions are subject to the slowing-down and pitch-angle collisions. The Monte Carlo method is used for the pitch-angle scattering, and the friction term is added to the equation of motion to show the effects of the slowing-down collision, such as the deposited power profile. The calculation parameters used are relevant to the NB injection on the FRC injection experiment device [T. Asai, Y. Suzuki, T. Yoneda, F. Kodera, M. Okubo, and S. Goto, Phys. Plasmas 7, 2294 (2000)]. It is found that the dominant local power deposition occurs in the open field region between the X point and the mirror point because of a concentration of fast ions and a longer duration travel at the mirror reflection point. In the present calculation, the maximum deposited power to the FRC plasma is about 10% of the injected power. Although the pitch-angle scattering by Coulomb collision destroys the mirror confinement of NB injected fast ions, this effect is found to be negligible. The loss mechanism due to nonadiabatic fast ion motion, which is intrinsic in nonuniform FRC plasmas, has a much greater effect than the pitch-angle scattering by Coulomb collision

  1. Atmospheric Signatures and Effects of Space-based Relativistic Electron Beam Injection

    Science.gov (United States)

    Marshall, R. A.; Sanchez, E. R.; Kero, A.; Turunen, E. S.; Marsh, D. R.

    2017-12-01

    Future relativistic electron beam injection experiments have the potential to provide groundbreaking insights into the physics of wave-particle interactions and beam-neutral interactions, relevant to space physics and to fundamental plasma physics. However, these experiments are only useful if their signatures can be detected. In this work, we use a physics-based forward modeling framework to investigate the observable signatures of a relativistic beam interacting with the upper atmosphere. The modeling framework is based around the Electron Precipitation Monte Carlo (EPMC) model, used to simulate electron precipitation in the upper atmosphere. That model is coupled to physics-based models of i) optical emission production; ii) bremsstrahlung photon production and propagation; iii) D-region ion chemistry; and iv) VLF wave propagation in the Earth-ionosphere waveguide. Using these modeling tools, we predict the optical, X-ray, chemical, radar, and VLF signatures of a realistic beam injection, based on recent space-based accelerator designs. In particular, we inject a beam pulse of 10 mA for a duration of 500 μs at an energy of 1 MeV, providing a total pulse energy of 5 J. We further investigate variations in these parameters, in particular the total energy and the electron energy. Our modeling shows that for this 5 J pulse injection at 1 MeV electron energy, the optical signal is easily detectable from the ground in common emission bands, but the X-ray signal is likely too weak to be seen from either balloons or LEO orbiting spacecraft. We further predict the optical signal-to-noise ratio that would be expected in different optical systems. Chemical signatures such as changes to NOx and HOx concentrations are too short-lived to be detectable; however our modeling provides a valuable estimate of the total chemical response. Electron density perturbations should be easily measurable from ground-based high-power radars and via VLF subionospheric remote sensing

  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. Heat flux to the limiter during disruptions and neutral beam injection in Doublet-III

    International Nuclear Information System (INIS)

    Hino, T.; DeGrassie, J.; Taylor, T.S.; Hopkins, G.; Meyer, C.; Petrie, T.W.; Kahn, C.L.; Ejima, S.

    1984-01-01

    The heat flux to the Doublet-III primary limiter has been monitored during plasma disruptions and during neutral beam injection. The surface temperature of the movable TiC-coated graphite limiter was measured with an Inframetrics thermal imaging system and a suitably filtered silicon photodiode spot detector. In addition, the floating electric potential of the limiter with respect to the vacuum vessel was measured. The heat pulse duration to the limiter was measured by the spot detector with a time response of x approx.= 10 μs and these times were correlated with the plasma parameters. In limiter discharges, 20% of the plasma kinetic stored energy goes to the limiter during disruptions. The power balance during disruptions is also discussed. During neutral beam injection, the limiter is not heated uniformly; the ion drift side receives much more thermal flux than the electron drift side. The fraction of beam power going to the limiter is as high as approx.= 35% in normal limiter discharges. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Masaaki [Princeton Plasma Physics Laboratory, Princeton University Princeton, New Jersey USA (United States)

    2016-03-25

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Wittig, Georg; Karger, Oliver S.; Knetsch, Alexander [Institute of Experimental Physics, University of Hamburg, 22761 Hamburg (Germany); Xi, Yunfeng; Deng, Aihua; Rosenzweig, James B. [Particle Beam Physics Laboratory, UCLA, Los Angeles, CA 90095 (United States); Bruhwiler, David L. [RadiaSoft LLC, Boulder, CO 80304 (United States); RadiaBeam Technologies LLC (United States); Smith, Jonathan [Tech-X UK Ltd, Daresbury, Cheshire WA4 4FS (United Kingdom); Sheng, Zheng-Ming; Jaroszynski, Dino A.; Manahan, Grace G. [Physics Department, SUPA, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Hidding, Bernhard [Institute of Experimental Physics, University of Hamburg, 22761 Hamburg (Germany); Physics Department, SUPA, University of Strathclyde, Glasgow G4 0NG (United Kingdom)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    S.S. Medley; D.S. Darrow; D. Liu; A.L. Roquemore

    2005-03-25

    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 (I{sub p} {approx} 0.5 MA) and electron density (n{sub e} {approx} 1 x 10{sup 13} cm{sup -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.

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

    Science.gov (United States)

    Burdakov, A. V.; Postupaev, V. V.

    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.

  8. Online Measurement of the Energy Spread of Multi-Turn Beam in the Fermilab Booster at Injection

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, J. [Brown U.; Bhat, C. M. [Fermilab; Hendricks, B. S. [Fermilab

    2017-07-01

    We have developed a computer program interfaced with the ACNET environment of Fermilab accelerators to measure energy spread of the proton beam from the LINAC at an injection into the Booster. It uses a digitizing oscilloscope and provides users an ability to configure the scope settings for optimal data acquisition from a resistive wall current monitor. When the program is launched, a) a one shot timeline is generated to initiate beam injection into the Booster, b) a gap of about 40 ns is produced in the injected beam using a set of fast kickers, c) collects line charge distribution data from the wall current monitor for the first 200 μs from the injection and d) performs complete data analysis to extract full beam energy spread of the beam. The program also gives the option to store the data for offline analyses. We illustrate a case with an example. We also present results on beam energy spread as a function of beam intensity from recent measurements.

  9. A Computer Program to Measure the Energy Spread of Multi-turn Beam in the Fermilab Booster at Injection

    Science.gov (United States)

    Nelson, Jovan; Bhat, Chandrashekhara; Hendricks, Brian

    2016-03-01

    We have developed a computer program interfaced with the ACNET environment for Fermilab accelerators in order to measure the energy spread of the injected proton beam from the LINAC, at the energy of 400 MeV. This program allows the user to configure a digitizing oscilloscope and timing devices to optimize data acquisition from a resistive wall current monitor. When the program is launched, it secures control of the oscilloscope and then generates a ``one-shot'' timeline which initiates injection into the Booster. Once this is complete, a kicker is set to create a notch in the beam and the line charge distribution data is collected by the oscilloscope. The program then analyzes this data in order to obtain notch width, beam revolution period, and beam energy spread. This allows the program to be a possible useful diagnostic tool for the beginning of the acceleration cycle for the proton beam. Thank you to the SIST program at Fermilab.

  10. Electrostatic potential generated by perpendicular neutral-beam injection to a tokamak plasma

    Science.gov (United States)

    Yamaguchi, H.; Murakami, S.

    2018-01-01

    The electrostatic potential generated by neutral-beam-injection (NBI) heating in a tokamak plasma is investigated using numerical simulations. The density distribution of the NBI fast ions in an assumed tokamak is evaluated using the GNET drift-kinetic-equation solver which is based on the Monte Carlo method. The electrostatic potential is evaluated assuming an adiabatic response of the electrons to the fast-ion density distribution in the plasma. It is found that an electrostatic potential peak is generated near the beam-injection point owing to the trapped fast ions satisfying the zero-precession condition. An analytic model expressing the expected potential except for the peak is derived and shows a good agreement with the radial distribution and linear dependence on the electron temperature predicted by the simulation within a factor of 1–2. The existence of three-dimensional electrostatic trapping may break the poloidally-closed particle orbits, and may change the spatial distribution and transport of high-Z impurity ions.

  11. High beta results in ISX-B with intense neutral beam injection

    International Nuclear Information System (INIS)

    Edmonds, P.H.; Bates, S.C.; Bell, J.D.

    1982-01-01

    Experiments on the ISX-B device show a deterioration in confinement at high beam power. In particular the electron energy confinement time falls catastrophically with increasing beam power. The maximum volume averaged beta values achieved are <2.5%; this is much less than would be predicted by extrapolating the low power data. Elongation has not been observed to have any significant effect on the maximum attainable beta, perhaps due to the limited range of both internal and external elongation. The electron energy confinement time does not follow Alcator scaling at high injection powers. There are two likely candidates for the loss of confinement. The phenomena may be β/sub p/ specific and caused by the gradual onset of resistive MHD pressure driven modes producing deteriorating confinement through fluctuations in the poloidal magnetic field. Alternatively the phenomena may be specific to the method of heating, neutral injection, being caused, for example, by plasma rotation, where the rotation speed approaches the ion thermal velocity. Experiments are in progress to investigate both of these possibilities

  12. Monte Carlo simulation of neutral beam injection in the Wendelstein VII-A stellarator

    International Nuclear Information System (INIS)

    Maassberg, H.

    1986-06-01

    Strong neutral beam heating in the W VII-A stellarator with injection nearly perpendicular to the magnetic field results in a high energy ion tail. In a simplified model, the full nonlinear Fokker-Planck equation based on Coulomb interactions is solved self-consistently by means of Monte Carlo techniques. Generalized scattering operators which are equivalent to the nonlinear Fokker-Planck collision term are derived. With the numerical simulation, the strong neutral beam heating is analyzed for a typical discharge in W VII-A with H 0 injection in a H + /D + plasma mixture for stationary conditions. Both deuterium and hydrogen distribution functions are calculated. The D + distribution is found to be highly isotropic, the deviation from a Maxwellian resulting mainly from electron cooling. Furthermore, ion heat conduction is of minor importance for the energy balance of the bulk part of the plasma. The H + distribution, however, develops a strong pressure anisotropy, which can also be deduced experimentally from the diamagnetic signal. (orig.)

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

    International Nuclear Information System (INIS)

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

    2001-01-01

    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 4 4 6 4 configuration of TJ-II, but future works will start a systematic scan of configuration using this same model. (Author) 12 Refs

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

    Energy Technology Data Exchange (ETDEWEB)

    Kittimanapun, K., E-mail: kritsadak@slri.or.th [National Superconducting Cyclotron Laboratory (NSCL), Michigan State University (MSU), 640 S. Shaw Lane, East Lansing, Michigan 48824 (United States); Synchrotron Light Research Institute (SLRI), 111 University Avenue, Muang District, Nakhon Ratchasima, 30000 (Thailand); Baumann, T.M.; Lapierre, A.; Schwarz, S. [National Superconducting Cyclotron Laboratory (NSCL), Michigan State University (MSU), 640 S. Shaw Lane, East Lansing, Michigan 48824 (United States); Bollen, G. [National Superconducting Cyclotron Laboratory (NSCL), Michigan State University (MSU), 640 S. Shaw Lane, East Lansing, Michigan 48824 (United States); Facility for Rare Isotope Beams (FRIB), Michigan State University, 640 S. Shaw Lane, East Lansing, Michigan 48824 (United States)

    2015-11-11

    The ReA post-accelerator at the National Superconducting Cyclotron Laboratory (NSCL) employs an electron beam ion trap (EBIT) as a charge breeder. A Monte-Carlo simulation code was developed to calculate the transverse acceptance phase space of the EBIT for continuously injected ion beams and to determine the capture efficiency in dependence of the transverse beam emittance. For this purpose, the code records the position and time of changes in charge state of injected ions, leading either to capture or loss of ions. To benchmark and validate the code, calculated capture efficiencies were compared with results from a geometrical model and measurements. The results of the code agree with the experimental findings within a few 10%. The code predicts a maximum total capture efficiency of 50% for EBIT parameters readily achievable and an efficiency of up to 80% for an electron beam current density of 1900 A/cm{sup 2}.

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  16. 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...

  17. Experimental investigation of the ripple induced losses of perpendicularly injected beam ions in the low aspect ratio helical system CHS

    International Nuclear Information System (INIS)

    Isobe, M.; Sasao, M.; Okamura, S.; Murakami, S.; Minami, T.; Kado, S.; Ida, K.; Osakabe, M.; Yoshimura, Y.; Tanaka, K.; Takahashi, C.; Nishimura, S.; Matsuoka, K.; Kondo, T.; Shimizu, A.; Yavorskij, V.A.

    2001-01-01

    Confinement of perpendicularly injected beam ions has been investigated experimentally both in the standard configuration and in the drift optimized configuration of the CHS heliotron/torsatron by means of the neutron technique. The experimental results indicate that the confinement of trapped beam ions is poor in both configurations. The observed loss rate of trapped beam ions was very high and this high rate is not explained by losses due to charge exchange or collisional scattering from the timescale perspective. Full gyro-motion following orbit calculations showed that in the peripheral region of CHS plasmas, trapped beam ions are promptly lost because they immediately intersect the vacuum chamber wall due to their large Larmor radii. It also suggested that in the core domain the collisionless transition behaviour is the key to understanding the rapid loss of beam ions. It was shown that the magnetic moment of perpendicularly injected beam ions is not well conserved in CHS. The rapid losses of perpendicularly injected beam ions are probably due to non-adiabatic effects resulting in the transition behaviour of energetic ions. (author)

  18. Experimental investigation of the ripple induced losses of perpendicularly injected beam ions in the low aspect ratio helical system CHS

    Science.gov (United States)

    Isobe, M.; Sasao, M.; Okamura, S.; Kondo, T.; Murakami, S.; Minami, T.; Kado, S.; Ida, K.; Shimizu, A.; Osakabe, M.; Yoshimura, Y.; Tanaka, K.; Takahashi, C.; Nishimura, S.; Matsuoka, K.; CHS Group; Yavorskij, V. A.

    2001-09-01

    Confinement of perpendicularly injected beam ions has been investigated experimentally both in the standard configuration and in the drift optimized configuration of the CHS heliotron/torsatron by means of the neutron technique. The experimental results indicate that the confinement of trapped beam ions is poor in both configurations. The observed loss rate of trapped beam ions was very high and this high rate is not explained by losses due to charge exchange or collisional scattering from the timescale perspective. Full gyro-motion following orbit calculations showed that in the peripheral region of CHS plasmas, trapped beam ions are promptly lost because they immediately intersect the vacuum chamber wall due to their large Larmor radii. It also suggested that in the core domain the collisionless transition behaviour is the key to understanding the rapid loss of beam ions. It was shown that the magnetic moment of perpendicularly injected beam ions is not well conserved in CHS. The rapid losses of perpendicularly injected beam ions are probably due to non-adiabatic effects resulting in the transition behaviour of energetic ions.

  19. 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.

  20. Electron temperature profile behaviour in TFTR during neutral beam injection and multiple pellet fuelling

    International Nuclear Information System (INIS)

    Taylor, G.; Fredrickson, E.D.; Grek, B.

    1989-01-01

    The electron temperature profiles on the Tokamak Fusion Test Reactor (TFTR) are determined by several diagnostics, including multi-point Thomson scattering and electron cyclotron emission measured with heterodyne radiometers and a Michelson interferometer. The electron temperature profiles are characterized by very high central temperatures (> 8 keV) and large Shafranov shifts (> 35 cm). The large Shafranov shifts suggest the necessity of mapping to magnetic flux surfaces when investigating the profile behaviour. During 1986, TFTR was operated with up to 20 MW of deuterium neutral beam injection (NBI) and a deuterium pellet injector. The electron temperature profile measurements were made on plasmas with 2.7 T p dia up to 2.2, 1x10 19 e 20 m -3 and 2.5 cyl e (R) to flux surfaces are investigated as well as the extent to which the electron temperature profile away from the core remains invariant to these perturbations. (author). 27 refs, 14 figs

  1. 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

  2. Plasma dynamics near an earth satellite and neutralization of its electric charge during electron beam injection into the ionosphere

    International Nuclear Information System (INIS)

    Fedorov, V.A.

    2000-01-01

    A study is made of the dynamics of the ionospheric plasma in the vicinity of an earth satellite injecting an electron beam. The time evolution of the electric charge of the satellite is determined. The electric potential of the satellite is found to be well below the beam-cutoff potential. It is shown that, under conditions typical of active experiments in space, the plasma electrons are capable of neutralizing the satellite's charge

  3. Design of arc power supply for neutral beam injection system based on super capacitor energy storage

    International Nuclear Information System (INIS)

    Yang Puqiong; Xuan Weimin; Cao Jianyong; Li Qing; Liu Xiaolong

    2015-01-01

    The arc power supply is one of the most important equipment for neutral beam injection system. The stability of arc discharge and the quality of ion beam extraction were determined by its performance. For improving stability of the arc discharge, reducing the power network capacity and decreasing impulse on power network, the topology of the arc power supply applied the structure of DC/DC converter based on technology of super capacitor energy storage and switching power supply. Several IGBT power modules are operated in parallel, and it can improve the arc power supply's operating frequency and dynamic response. A filter circuit and a current fast transferring circuit were designed based on a detailed analysis on working process of the arc power sup- ply. According to the requirements and parameters of the arc power supply, and the current response of RL first order circuit, the minimum filter inductances were accurately calculated. Finally, using the model and Matlab, the performance of the arc power supply was simulated and verified, and it meets the design requirement. (authors)

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

    Directory of Open Access Journals (Sweden)

    Andrea Franchi

    2015-07-01

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

  5. 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.

  6. Destabilization of counter-propagating TAEs by off-axis, co-current Neutral Beam Injection

    Science.gov (United States)

    Podesta', M.; Fredrickson, E.; Gorelenkova, M.

    2017-10-01

    Neutral Beam injection (NBI) is a common tool to heat the plasma and drive current non-inductively in fusion devices. Energetic particles (EP) resulting from NBI can drive instabilities that are detrimental for the performance and the predictability of plasma discharges. A broad NBI deposition profile, e.g. by off-axis injection aiming near the plasma mid-radius, is often assumed to limit those undesired effects by reducing the radial gradient of the EP density, thus reducing the ``universal'' drive for instabilities. However, this work presents new evidence that off-axis NBI can also lead to undesired effects such as the destabilization of Alfvénic instabilities, as observed in NSTX-U plasmas. Experimental observations indicate that counter propagating toroidal AEs are destabilized as the radial EP density profile becomes hollow as a result of off-axis NBI. Time-dependent analysis with the TRANSP code, augmented by a reduced fast ion transport model (known as kick model), indicates that instabilities are driven by a combination of radial and energy gradients in the EP distribution. Understanding the mechanisms for wave-particle interaction, revealed by the phase space resolved analysis, is the basis to identify strategies to mitigate or suppress the observed instabilities. Work supported by the U.S. Department of Energy, Office of Science, Office of Fusion Energy Sciences under Contract Number DE-AC02-09CH11466.

  7. High energy asymptotics of cross sections and multiparametric dependencies in effective data relevant for neutral beam injection

    International Nuclear Information System (INIS)

    Reiter, D.

    2016-01-01

    The possible scope of a new CRP on atomic data relevant for neutral beam injection (NBI) should be to constrain and focus on the data issues to all processes relevant when the beam particles have left the sources, which include beam interacting Maxwellian electrons as penetrating plasma edge. The special attention is needed for cross-sections at high energy regions and asymptotic behaviors. Currently available data sets of some relevant processes such as heavy particle collisions involving He and metastable He are lacking the correct asymptotic behaviors at low and high energies.

  8. Optics measurements and transfer line matching for the SPS injection of the CERN Multi-Turn Extraction beam

    CERN Document Server

    Benedetto, E; Cettour Cave, S; Follin, F; Gilardoni, S; Giovannozzi, M; Roncarolo, F

    2010-01-01

    Dispersion and beam optics measurements were carried out in the transfer line between the CERN PS and SPS for the new Multi-Turn Extraction beam. Since the extraction conditions of the four islands and the core are different and strongly dependent on the non-linear effects used to split the beam in the transverse plane, a special care was taken during the measurement campaigns. Furthermore, an appropriate strategy was devised to minimize the overall optical mismatch at SPS injection. All this led to a new optical configuration that will be presented in the paper.

  9. Characteristics of a long-pulse (30-s), high-power (4-MW) ion source for neutral beam injection

    International Nuclear Information System (INIS)

    Menon, M.M.; Barber, G.C.; Combs, S.K.

    1983-01-01

    A quasi-steady-state ion source has been developed for neutral beam injection applications. It is of the duoPIGatron type designed for delivering 50 A of hydrogen ions at 80 keV for 30-s-long pulses. Ion beams of 40 A at 75 keV were extracted for pulse lengths up to 30 s, maintaining excellent optical quality in the beam for the entire pulse duration. The design features and operational characteristics of the ion source are elaborated

  10. Single-shot measurements of low emittance beams from laser-plasma accelerators comparing two triggered injection methods

    Science.gov (United States)

    van Tilborg, Jeroen

    2017-10-01

    The success of laser plasma accelerator (LPA) based applications, such as a compact x-ray free electron laser (FEL), relies on the ability to produce electron beams with excellent 6D brightness, where brightness is defined as the ratio of charge to the product of the three normalized emittances. As such, parametric studies of the emittance of LPA generated electron beams are essential. Profiting from a stable and tunable LPA setup, combined with a carefully designed single-shot energy-dispersed emittance diagnostic, we present a direct comparison of charge dependent emittance measurements of electron beams generated by two different injection mechanisms: ionization injection and shock-induced density down-ramp injection. Both injection mechanisms have gained in popularity in recent years due to their demonstrated stable LPA performance. For the down-ramp injection configuration, normalized emittances a factor of two lower were recorded: less than 1 micron at spectral charge densities up to 2 pC/MeV. For both injection mechanisms, a contributing correlation of space charge to the emittance was identified. This measurement technique in general, and these results specifically, are critical to the evaluation of LPA injection methods and development of high-quality LPA beam lines worldwide. This work is supported by the U.S. DOE under Contract No. DE-AC02-05CH11231, by the U.S. DOE NNSA, DNN R&D (NA22), by the National Science Foundation under Grant No. PHY-1415596, and by the Gordon and Betty Moore Foundation under Grant ID GBMF4898.

  11. 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...

  12. Measurements of the fast ion distribution during neutral beam injection and ion cyclotron heating in ATF [Advanced Toroidal Facility

    International Nuclear Information System (INIS)

    Wade, M.R.; Kwon, M.; Thomas, C.E.; Colchin, R.J.; England, A.C.; Gossett, J.M.; Horton, L.D.; Isler, R.C.; Lyon, J.F.; Rasmussen, D.A.; Rayburn, T.M.; Shepard, T.D.; Bell, G.L.; Fowler, R.H.; Morris, R.N.

    1990-01-01

    A neutral particle analyzer (NPA) with horizontal and vertical scanning capability has been used to make initial measurements of the fast ion distribution during neutral beam injection (NBI) and ion cyclotron heating (ICH) on the Advanced Toroidal Facility (ATF). These measurements are presented and compared with the results of modeling codes that predict the analyzer signals during these heating processes. 6 refs., 5 figs

  13. 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.

  14. Manufacture of New Set of Calorimeter Panels for the Neutral Beam Injection of ASDEX Upgrade

    International Nuclear Information System (INIS)

    Huber, T.; Zabernig, A.; Riedel, R.; Schedler, B.; Froeschle, M.; Heinemann, B.; Entcheva, A.; Weigert, J.

    2006-01-01

    The Neutral Injection of ASDEX-Upgrade employs calorimeter panels to measure the power of the neutral beam. These components are designed to safely absorb specific heat flux loads as high as 25 MW/m 2 over a period of 10 s. The currently used calorimeter panels have reached after ten years the end of their service life time and have to be replaced. The components consist of the CuCrZr which is a precipitation hardened alloy. The selection of the manufacturing process therefore determines the final thermal and mechanical properties of the alloy. In the past these components were manufactured by a two step brazing process, at about 830 o C and 730 o C, respectively. This led to an overaging of the material resulting in low mechanical properties. As predicted by finite element calculations the cyclic heat flux load leads to ratcheting at the heated surface finally limiting the life time of the components. In order to increase the service life time of the component it has therefore been decided to employ electron beam welding as the only joining technique to realise the required joints of the components. To fully characterise this manufacturing route a qualification programme has been performed, which ended in the manufacture of prototypes. These have been tested in ASEDEX Upgrade in comparison to brazed components. After successful qualification of design and processes the manufacture and testing of 100 calorimeter panels has been launched and completed recently. The used design, the results of the qualification tests, the manufacturing sequence and the applied non-destructive methods will be described in the paper. (author)

  15. Counter-crossing injection for stable high-quality electron beam generation via laser-plasma interaction

    Energy Technology Data Exchange (ETDEWEB)

    Kotaki, H; Daito, I; Hayashi, Y; Ma, J; Chen, L-M; Kando, M; Esirkepov, T Z; Fukuda, Y; Homma, T; Pirozhkov, A; Koga, J K; Nakajima, K; Daido, H; Bulanov, S V [Advanced Photon Research Center, Japan Atomic Energy Agency, Kizugawa, Kyoto (Japan)], E-mail: kotaki.hideyuki@jaea.go.jp

    2008-05-01

    Counter-crossing injection, which is a realistic setup for applications, by two sub-relativistic laser pulses colliding at an angle of 45 degrees is demonstrated. The collision of the two laser pulses generates a high-quality electron beam with high reproducibility. The generated monoenergetic electron beam has a peak energy of 14.4 MeV, an energy spread of 10.6%, a charge of 21.8 pC, a normalized emittance of 1.6 {pi} mm mrad, and a reproducibility of 50%. The electron beam generation is unfolded with two-dimensional-particle-in-cell simulations. The laser pulses in plasma are self-focused to higher intensity when the laser power is above the threshold for relativistic self-focusing. The collision of the self-focused laser pulses generates a high-quality electron beam with high reproducibility.

  16. High heat flux engineering for the upgraded neutral beam injection systems of MAST-U

    Energy Technology Data Exchange (ETDEWEB)

    Dhalla, F., E-mail: Fahim.dhalla@ccfe.ac.uk; Mistry, S.; Turner, I.; Barrett, T.R.; Day, I.; McAdams, R.

    2015-10-15

    Highlights: • A new Residual Ion Dump (RID) and bend magnet system for the upgraded NBI systems have been designed for the 5 s MAST-U pulse requirements. • Design scoping was performed using numerical ion-tracing analysis software (MAGNET and OPERA codes). • A more powerful bending magnet will separate the residual ions into full, half and third energy components. • Three separate CuCrZr dumps spread the power loading resulting in acceptable power footprints. • FE thermo-mechanical analyses using ANSYS to validate the designs against the ITER SDC-IC code. • New bend magnet coils, yoke and CuCrZr water-cooled plates are in the procurement phase. - Abstract: For the initial phase of MAST-U operation the two existing neutral beam injection systems will be used, but must be substantially upgraded to fulfil expected operational requirements. The major elements are the design, manufacture and installation of a bespoke bending magnet and Residual Ion Dump (RID) system. The MAST-design full energy dump is being replaced with new actively-cooled full, half and third energy dumps, designed to receive 2.4 MW of ion power deflected by an iron-cored electromagnet. The main design challenge is limited space available in the vacuum vessel, requiring ion-deflection calculations to ensure acceptable heat flux distribution on the dump panels. This paper presents engineering and physics analysis of the upgraded MAST beamlines and reports the current status of manufacture.

  17. Thermo-mechanical analysis of an acceleration grid for the international thermonuclear experimental reactor-neutral beam injection system

    International Nuclear Information System (INIS)

    Fujiwara, Yukio; Hanada, Masaya; Okumura, Yoshikazu; Suzuki, Satoshi; Watanabe, Kazuhiro

    2001-01-01

    In the engineering design of a negative-ion beam source for a high-power neutral beam injection (NBI) system, one of the most important issues is thermo-mechanical design of acceleration grids for producing several tens of MW ion beams. An acceleration grid for the international thermonuclear experimental reactor-neutral beam injection (ITER-NBI) system will be subjected to the heat loading as high as 1.5 MW. In the present paper, thermo-mechanical characteristics of the acceleration grid for the ITER-NBI system were analyzed. Numerical simulation indicated that maximum aperture-axis displacement of the acceleration grid due to thermal expansion would be about 0.7 mm for the heat loading of 1.5 MW. From the thin lens theory of beam optics, beamlet deflection angle by the aperture-axis displacement was estimated to be about 2 mrad, which is within the requirement of the engineering design of the ITER-NBI system. Numerical simulation also indicated that no melting on the acceleration grid would occur for a heat loading of 1.5 MW, while local plastic deformation would happen. To avoid the plastic deformation, it is necessary to reduce the heat loading onto the acceleration grid to less than 1 MW

  18. Differential rotation of plasma in the GOL-3 multiple-mirror trap during injection of a relativistic electron beam

    Science.gov (United States)

    Ivanov, I. A.; Burdakov, A. V.; Burmasov, V. S.; Kuklin, K. N.; Makarov, M. A.; Mekler, K. I.; Polosatkin, S. V.; Postupaev, V. V.; Rovenskikh, A. F.; Sidorov, E. N.; Sinitsky, S. L.; Sudnikov, A. V.

    2017-02-01

    Results of spectral and magnetic diagnostics of plasma differential rotation in the GOL-3 multiplemirror trap are presented. It is shown that the maximum frequency of plasma rotation about the longitudinal axis reaches 0.5 MHz during the injection of a relativistic electron beam into the plasma. The data of two diagnostics agree if there is a region with a higher rotation frequency near the boundary of the electron beam. Plasma differential rotation can be an additional factor stabilizing interchange modes in the GOL-3 facility.

  19. The effect of space charge on beam transport through the injection system of the Lund Pelletron accelerator

    International Nuclear Information System (INIS)

    Dymnikov, A.; Hellborg, R.; Pallon, J.; Skog, G.; Yang, C.; Ohlen, G.

    1993-01-01

    A new recursive technique is used for the solution of the equations of motion for charged particles, taking into account the effect of space charge. The paraxial equations are solved for an infinitely long beam with an elliptical cross-section in a static electric field. An effective computer code, based on the method of a continuous generalized analogue of the Gauss brackets and on the method of the envelope matrix, has been written. The code has been used to study the beam dynamics in the injection system of the Pelletron electrostatic accelerator in Lund. (orig.)

  20. The effect of space charge on beam transport through the injection system of the Lund Pelletron accelerator

    Science.gov (United States)

    Dymnikov, A.; Hellborg, R.; Pallon, J.; Skog, G.; Yang, C.; Ohlén, G.

    1993-04-01

    A new recursive technique is used for the solution of the equations of motion for charged particles, taking into account the effect of space charge. The paraxial equations are solved for an infinitely long beam with an elliptical cross-section in a static electric field. An effective computer code, based on the method of a continuous generalized analogue of the Gauss brackets and on the method of the envelope matrix, has been written. The code has been used to study the beam dynamics in the injection system of the Pelletron electrostatic accelerator in Lund.

  1. Pulse radiolysis based on a femtosecond electron beam and a femtosecond laser light with double-pulse injection technique

    International Nuclear Information System (INIS)

    Yang Jinfeng; Kondoh, Takafumi; Kozawa, Takahiro; Yoshida, Youichi; Tagawa, Seiichi

    2006-01-01

    A new pulse radiolysis system based on a femtosecond electron beam and a femtosecond laser light with oblique double-pulse injection was developed for studying ultrafast chemical kinetics and primary processes of radiation chemistry. The time resolution of 5.2 ps was obtained by measuring transient absorption kinetics of hydrated electrons in water. The optical density of hydrated electrons was measured as a function of the electron charge. The data indicate that the double-laser-pulse injection technique was a powerful tool for observing the transient absorptions with a good signal to noise ratio in pulse radiolysis

  2. Influence of the injected beam parameters on the capture efficiency of an electron cyclotron resonance based charge breeder

    Directory of Open Access Journals (Sweden)

    A. Galatà

    2017-06-01

    Full Text Available Electron cyclotron resonance ion sources based charge breeders (ECR-CB are fundamental devices for Isotope Separation On Line (ISOL facilities aiming at postaccelerating radioactive ion beams (RIBs. Presently, low intensity RIBs do not allow a conventional tuning of the ECR-CB: as a consequence, it has to be set with a stable 1+ pilot beam first, switching then to the radioactive one without changing any parameter; this procedure is usually called “blind tuning.” Besides having different masses, pilot and radioactive beams can also differ in terms of the rms transverse emittance ε_{rms} and/or longitudinal energy spread ΔE, so the choice of a given pilot beam can determine the overall performances of the final breeding stage. This paper shows a numerical study of how the capture efficiency of the PHOENIX charge breeder is affected by the aforementioned beam paramaters: the analysis reveals the two-step nature of the process, highlighting the role of the injection optics and the plasma capture capability in the overall performances of this device. The simulations predict highest efficiency for ε_{rms}<5π  mm mrad and ΔE<5  eV in a optimum energy range between 2 and 6 eV, thus giving important information on the possibility of blindly tuning an ECR-CB. No isotopical effects were observed, while it clearly came out the necessity to improve the 1+ beam characteristics with a rf beam cooler prior to the injection into an ECR-CB.

  3. Feasibility of driving perpendicular rotation in core plasma by off-axis neutral beam injection to suppress microturbulence

    International Nuclear Information System (INIS)

    Hassam, A.B.

    1993-01-01

    Various aspects pertaining to driving perpendicular rotation in core plasma with neutral beam injection to suppress microturbulence are discussed. The assessment is based on the premise that a critical perpendicular velocity shear of order C s /L s is required to effect significant turbulence suppression. The equilibrium of a tokamak plasma rotating poloidally at such high frequencies is examined from drift-kinetic theory. It is shown that a substantial fraction of trapped particles is now detrapped. The calculation also shows that viscous damping from magnetic pumping falls off as the square of the poloidal speed. This reduction in viscous damping makes more efficacious the driving of large poloidal flows from off-axis neutral beam injection. The feasibility of exceeding the critical velocity shear is assessed, both for present day tokamaks as well as for reactor parameters. The magnetohydrodynamic stability of tokamak plasma rotating at high speeds with respect to Kelvin-Helmholtz and interchange modes is assessed

  4. Beam loss reduction by injection painting in the 3-GeV rapid cycling synchrotron of the Japan Proton Accelerator Research Complex

    Directory of Open Access Journals (Sweden)

    H. Hotchi

    2012-04-01

    Full Text Available The 3-GeV rapid cycling synchrotron (RCS of the Japan Proton Accelerator Research Complex was commissioned in October 2007. Via the initial beam tuning and a series of underlying beam studies with low-intensity beams, since December 2009, we have intermittently been performing beam tuning experiments with higher-intensity beams including the injection painting technique. By optimizing the injection painting parameters, we have successfully achieved a 420 kW-equivalent output intensity at a low-level intensity loss of less than 1%. Also the corresponding numerical simulation well reproduced the observed painting parameter dependence on the beam loss, and captured a characteristic behavior of the high-intensity beam in the injection painting process. In this paper, we present the experimental results obtained in the course of the RCS beam power ramp-up, especially on the beam loss reduction achieved by employing the injection painting, together with the numerical simulation results.

  5. Analysis of particle species evolution in neutral-beam injection lines

    International Nuclear Information System (INIS)

    Kim, J.; Haselton, H.H.

    1979-01-01

    Analytic solutions to the rate equations describing the species evolution of a multispecies positive ion beam of hydrogen due to charge exchange and molecular dissociation are derived as a function of the background gas (H 2 ) line density in the neutralizing gas cell and in the drift tube. Using the solutions, calculations are presented for the relative abundance of each species as a function of the gas-cell thickness, the reionization loss in the drift tube, and the neutral-beam power as a function of the beam energy and the species composition of the original ion beam

  6. Electron energy distribution function in the divertor region of the COMPASS tokamak during neutral beam injection heating

    Science.gov (United States)

    Hasan, E.; Dimitrova, M.; Havlicek, J.; Mitošinková, K.; Stöckel, J.; Varju, J.; Popov, Tsv K.; Komm, M.; Dejarnac, R.; Hacek, P.; Panek, R.; the COMPASS Team

    2018-02-01

    This paper presents the results from swept probe measurements in the divertor region of the COMPASS tokamak in D-shaped, L-mode discharges, with toroidal magnetic field BT = 1.15 T, plasma current Ip = 180 kA and line-average electron densities varying from 2 to 8×1019 m-3. Using neutral beam injection heating, the electron energy distribution function is studied before and during the application of the beam. The current-voltage characteristics data are processed using the first-derivative probe technique. This technique allows one to evaluate the plasma potential and the real electron energy distribution function (respectively, the electron temperatures and densities). At the low average electron density of 2×1019 m-3, the electron energy distribution function is bi-Maxwellian with a low-energy electron population with temperatures 4-6 eV and a high-energy electron group 12-25 eV. As the line-average electron density is increased, the electron temperatures decrease. At line-average electron densities above 7×1019 m-3, the electron energy distribution function is found to be Maxwellian with a temperature of 6-8.5 eV. The effect of the neutral beam injection heating power in the divertor region is also studied.

  7. Dust appearance rates during neutral beam injection and after oxygen bake in the DIII-D tokamak

    International Nuclear Information System (INIS)

    Yu, J.H.; Smirnov, R.D.; Rudakov, D.L.

    2011-01-01

    A simple model to quantify source and sink terms of dust observed in tokamaks using fast visible imaging is presented. During neutral beam injection (NBI), dust appearance rates increase in front of the neutral beam port by up to a factor of 5. The images show dust streaming from the port box as previously settled dust becomes mobilized during beam injection. Following an oxygen bake and vent, the dust observation rate is a factor of 2 lower than that after a vessel entry vent with no oxygen bake. Detected dust levels decay on a shot-to-shot basis in a roughly exponential fashion, with a decay time of approximately 20 s of plasma exposure. Appearance rates of dust mass are estimated using assumed lognormal and power law functional forms for the dust size distribution. The two dust size distributions differ significantly on the amount the dust material carried by the largest particles, highlighting the need for further dust studies in order to make accurate forecasts to ITER.

  8. The internal kink mode in an anisotropic flowing plasma with application to modeling neutral beam injected sawtoothing discharges

    Science.gov (United States)

    Graves, J. P.; Sauter, O.; Gorelenkov, N. N.

    2003-04-01

    For some time it has not been clear to what extent neutral injected beam ions have a stabilizing influence on sawteeth. To investigate this, the well known toroidal internal kink instability is generalized to account for weakly anisotropic and flowing equilibria. An analytical approach is proposed, which upon employing an appropriate model distribution function, accurately accounts for the hot ion response of neutral beam injection (NBI) to the internal kink mode. Large fluid contributions, which are expected to arise as a consequence of the anisotropic velocity deposition of NBI, are identified and shown to be stabilizing to the internal kink mode for populations with large passing fractions. In particular for tangential injection, such as that employed in the Joint European Torus [J. Wesson, Tokamaks, 2nd ed. (Oxford Science, Oxford, 1997), p. 581], it is found that fast ion stabilization can be dominated by anisotropic fluid effects rather than kinetic effects. In contrast, for predominantly trapped populations, the anisotropic fluid effects are destabilizing and thus reduce the stabilizing role of fast ions. This is especially evident for cases where the subsonic sheared toroidal plasma rotation induced by unbalanced NBI reduces kinetic stabilization. Sheared plasma rotation orientated either co or counter to the plasma current can reduce fast ion stabilization, but counter-rotation has the greatest effect by impeding the conservation of the third adiabatic invariant.

  9. Stable, tunable, quasimonoenergetic electron beams produced in a laser wakefield near the threshold for self-injection

    Directory of Open Access Journals (Sweden)

    S. Banerjee

    2013-03-01

    Full Text Available Stable operation of a laser-plasma accelerator near the threshold for electron self-injection in the blowout regime has been demonstrated with 25–60 TW, 30 fs laser pulses focused into a 3–4 millimeter length gas jet. Nearly Gaussian shape and high nanosecond contrast of the focused pulse appear to be critically important for controllable, tunable generation of 250–430 MeV electron bunches with a low-energy spread, ∼10  pC charge, a few-mrad divergence and pointing stability, and a vanishingly small low-energy background. The physical nature of the near-threshold behavior is examined using three-dimensional particle-in-cell simulations. Simulations indicate that properly locating the nonlinear focus of the laser pulse within the plasma suppresses continuous injection, thus reducing the low-energy tail of the electron beam.

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

    International Nuclear Information System (INIS)

    Isler, R.C.; Crume, E.C.; Arnurius, D.E.; Murray, L.E.

    1980-10-01

    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

  11. Microwave Ion Source and Beam Injection for an Accelerator-driven Neutron Source

    International Nuclear Information System (INIS)

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

    2007-01-01

    An over-dense microwave driven ion source capable of producing deuterium (or hydrogen) beams at 100-200 mA/cm2 and with atomic fraction >90 percent was designed and tested with an electrostatic low energy beam transport section (LEBT). This ion source was incorporated into the design of an Accelerator Driven Neutron Source (ADNS). The other key components in the ADNS include a 6 MeV RFQ accelerator, a beam bending and scanning system, and a deuterium gas target. In this design a 40 mA D+ beam is produced from a 6 mm diameter aperture using a 60 kV extraction voltage. The LEBT section consists of 5 electrodes arranged to form 2 Einzel lenses that focus the beam into the RFQ entrance. To create the ECR condition, 2 induction coils are used to create ∼ 875 Gauss on axis inside the source chamber. To prevent HV breakdown in the LEBT a magnetic field clamp is necessary to minimize the field in this region. Matching of the microwave power from the waveguide to the plasma is done by an autotuner. We observed significant improvement of the beam quality after installing a boron nitride liner inside the ion source. The measured emittance data are compared with PBGUNS simulations

  12. Microwave Ion Source and Beam Injection for an Accelerator-Driven Neutron Source

    International Nuclear Information System (INIS)

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

    2007-01-01

    An over-dense microwave driven ion source capable of producing deuterium (or hydrogen) beams at 100-200 mA/cm 2 and with atomic fraction > 90% was designed and tested with an electrostatic low energy beam transport section (LEBT). This ion source was incorporated into the design of an Accelerator Driven Neutron Source (ADNS). The other key components in the ADNS include a 6 MeV RFQ accelerator, a beam bending and scanning system, and a deuterium gas target. In this design a 40 mA D + beam is produced from a 6 mm diameter aperture using a 60 kV extraction voltage. The LEBT section consists of 5 electrodes arranged to form 2 Einzel lenses that focus the beam into the RFQ entrance. To create the ECR condition, 2 induction coils are used to create ∼ 875 Gauss on axis inside the source chamber. To prevent HV breakdown in the LEBT a magnetic field clamp is necessary to minimize the field in this region. Matching of the microwave power from the waveguide to the plasma is done by an autotuner. They observed significant improvement of the beam quality after installing a boron nitride liner inside the ion source. The measured emittance data are compared with PBGUNS simulations

  13. 150-kV, 80-A solid state power supply for neutral beam injection

    International Nuclear Information System (INIS)

    Owren, H.; Baker, W.; Hopkins, D.; Milnes, K.

    1978-08-01

    A 150-kV, 80-A power supply and neutral beam test facility is now operational at the Lawrence Berkeley Laboratory, Berkeley, California. This supply uses banks of 450-V electrolytic capacitors for over 10 6 joules of energy storage. SCR switches control the power flow to the neutral beam accelerator. Turn on and off times of a few microseconds are possible. An auxiliary capacitor bank also uses SCR switches to provide regulation (''flat-topping'') of the main bank output by switching in additional capacitors as the main bank discharges. Air-operated switches are used to connect the main-bank sections in parallel for charging and series or parallel for discharge, depending on the operating voltage desired. A single digital switch sets the desired operating voltage. Filament and arc power supplies are also solid state. With the exception of the suppressor supply which has one vacuum tube the complete neutral beam system uses all solid state components

  14. The Nature of Transverse Beam Instabilities at Injection in the Fermilab Main Ring

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Ping Jung [Northwestern Univ., Evanston, IL (United States)

    1996-12-01

    Transverse beam instabilities have been observed in the Fermilab Main Ring since 1972. It was well controlled by two active feedback systems until the last fix target run in 1991. The current upgrade of accelerator facilities, where the replacement of the Main Ring by the Main Injector will allow acceleration of higher proton intensities, makes the importance of this issue surface again. Experimental studies were conducted to understand the nature and the cause of these transverse beam instabilities. The interplay between accelerator parameters and the growth rate of transverse beam oscillations is investigated. Some previously puzzling behavior of the Main Ring is now understood because of the knowledge gained from these studies. Experimental techniques were implemented to measure some important parameters of the Main Ring, such as the vertical impedance, bunch form factor, and the wake f~nction. Empirical theory is devised to understand the coupled bunch instability with many distributed gaps, and a satisfactory agreement is obtained between the analysis and the measured data. The cause of the transverse beam instabilities is identified to be the resistive wall impedance. Anomalous behavior in the frequency dependence of the impedance below the MHz range suggests that impedance sources other than the resistive wall also exist in the Main Ring. The performance of two active feedback systems is found to be inadequate to meet the goal of the Main Injector accelerator upgrade. Suggestions for hardware improvements and the choice of accelerator parameters are given.

  15. Hot ion buildup by low current neutron beam injection in LITE

    International Nuclear Information System (INIS)

    Tomlinson, R.G.; Ard, W.B.; Fader, W.J.; Polk, D.H.; Mensing, A.E.; Stufflebeam, J.H.

    1976-01-01

    The laser produced target plasma confined in the LITE minimum-B mirror magnetic field is shown along with a drawing of the confinement field line configuration. The plasma is generated by two beam, 1.06 micron, Nd-glass laser irradiation of LiH particles approximately 100 microns in diameter producing a plasma of approximately 10 16 hydrogen and lithium ions which expands in and is captured by the ''baseball'' confinement field. The plasma luminosity displays a plasma configuration which corresponds to the magnetic field geometry and indicates a plasma volume of approximately 400 cm 3 . Probe and microwave measurements confirm the plasma distribution indicated by the luminosity photographs. Charge collector probes located at a series of positions over a 120 0 arc in the mirror fan permit simultaneous observations of the plasma decay along field lines which pass through the mid-plane at different radial distances from the magnetic field axis. Plasma flux is observed with these probes to field lines 6 cm from the axis. Microwave measurements have been made with a strongly focused, 75 GHz (lambda = 4 mm) beam passing through the mid-plane, orthogonal to the mirror axis. Cut-off of the microwave beam transmission early in the confined plasma time history indicates that the radial dimension of the high density plasma region exceeds 2 cm. Measurement of the line density via interferometric measurements of the phase shift of the transmitted beam when the density has fallen below cut-off indicates an ''effective'' diameter of approximately 5 cm and an axial extent of approximately 20 cm. Thus, the plasma presents approximately 100 cm 2 target area to an incident neutral beam and occupies approximately 400 cm 3 volume

  16. Application of the OPTIMUS Code to the Neutral Beam Injection System of TJ-II

    International Nuclear Information System (INIS)

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

    1998-01-01

    The different losses processes affecting a neutral beam since is born into the ions source until is coming into the fusion machine, are dependent of the residual gas pressure distribution inside injector. The OPTIMUS code analyzes that losses and calculates the pressure distribution inside one injector with specific geometry. The adaptation of injector to TJ-II has not required important design changes, only the operating range of the gas flow and the pumping speed have modified. The calculations show that the required gas flows for the optimal operation of the system ned an independent pumping system for the calorimeter box with a pumping speed of 1200001/s. The system efficiency is not affected by an hypothetical beaming effect and it is found also that with a proper conditioning of the injector walls, so that the absorption coefficients do not surpass excessively the unity value, the injector operation remains optimal. (Author) 8 refs

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

    International Nuclear Information System (INIS)

    1981-01-01

    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

  18. Electro-optical characterization system develped for ATLIDCAS AIV: flat field and collimated beam injections

    Science.gov (United States)

    Ramos, G.; Laguna, H.; Torres, J.; Belenguer, T.

    2017-11-01

    In the framework of the ESA EarthCare Mission, an atmospheric LIDAR (ATLID) was included as a payload. CAS is the co-alignment system of such a LIDAR instrument, the system responsible of guaranteeing the proper alignment of the projected laser beam and the reflected light collected. Within CAS, in which a consortium leaded by ASTRIUM France is working in, as well as CRISA (electronics) and LIDAX (mechanical engineering), INTA is in charge of the development of the instrumentation to be used on ground (on ground support equipments, OGSEs) needed for the proper electro-optical characterization.

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

    International Nuclear Information System (INIS)

    Guasp, J.; Liniers, M.

    1998-01-01

    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

  20. Technique of Injection of Hyaluronic Acid as a Prostatic Spacer and Fiducials Before Hypofractionated External Beam Radiotherapy for Prostate Cancer.

    Science.gov (United States)

    Boissier, Romain; Udrescu, Corina; Rebillard, Xavier; Terrier, Jean-Etienne; Faix, Antoine; Chapet, Olivier; Azria, David; Devonec, Marian; Paparel, Philippe; Ruffion, Alain

    2017-01-01

    To describe a technique combining the implantation of fiducials and a prostatic spacer (hyaluronic acid [HA]) to decrease the rectal toxicity after an image-guided external beam radiotherapy (EBRT) with hypofractionation for prostate cancer and to assess the tolerance and the learning curve of the procedure. Thirty patients with prostate cancer at low or intermediate risk were included in a phase II trial: image-guided EBRT of 62 Gy in 20 fractions of 3.1 Gy with intensity-modulated radiotherapy. A transrectal implantation of 3 fiducials and transperineal injection of 10 cc of HA (NASHA gel spacer, Q-Med AB, Uppsala, Sweden) between the rectum and the prostate was performed by 1 operator. The thickness of HA was measured at 10 points on magnetic resonance imaging to establish a quality score of the injection (maximum score = 10) and determine the learning curve of the procedure. The quality score increased from patients 1-10, 11-20, to 21-30 with respective median scores: 7 [2-10], 5 [4-7], and 8 [3-10]. The average thicknesses of HA between the base, middle part, and apex of the prostate and the rectum were the following: 15.1 mm [6.4-29], 9.8 mm [5-21.2], and 9.9 mm [3.2-21.5]. The injection of the HA induced a median pain score of 4 [1-8] and no residual pain at mid-long term. Creating an interface between the rectum and the prostate and the implantation of fiducials were feasible under local anesthesia with a short learning curve and could become a standard procedure before a hypofractionated EBRT for prostate cancer. Copyright © 2016 Elsevier Inc. All rights reserved.

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

    International Nuclear Information System (INIS)

    Choi, M.; Pinsker, R. I.; Chan, V. S.; Muscatello, C. M.; Jaeger, E. F.

    2011-01-01

    In recent moderate to high harmonic fast wave heating and current drive experiments in DIII-D, a synergy effect was observed when the 6 th harmonic 90 MHz fast wave power is applied to the plasma preheated by neutral beams and the 4 th 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 4 th harmonic FW on beam ions accelerates them above the injection energy, which may allow significant damping of 6 th harmonic FW on beam ion tails to produce synergy.

  2. Low jitter metal vapor vacuum arc ion source for electron beam ion trap injections

    International Nuclear Information System (INIS)

    Holland, Glenn E.; Boyer, Craig N.; Seely, John F.; Tan, J.N.; Pomeroy, J.M.; Gillaspy, J.D.

    2005-01-01

    We describe a metal vapor vacuum arc (MeVVA) ion source containing eight different cathodes that are individually selectable via the control electronics which does not require moving components in vacuum. Inside the vacuum assembly, the arc plasma is produced by means of a 30 μs pulse (26 kV,125 A) delivering 2.4 mC of charge to the cathode sample material. The trigger jitter is minimized ( 9 ions/cm 2 , measured by an unbiased Faraday cup positioned 20 cm from the extractor grid, at discharge rates up to 5 Hz. The electronic triggering of the discharge is via a fiber optic interface. We present the design, fabrication details, and performance of this MeVVA, recently installed on the National Institute of Standards and Technology electron beam ion trap (EBIT)

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

    International Nuclear Information System (INIS)

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

    1996-01-01

    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)

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

    CERN Document Server

    AUTHOR|(SzGeCERN)395725

    2015-01-01

    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. Fastpulsing 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 inco...

  5. Plasma simulation by macroscale, electromagnetic particle code and its application to current-drive by relativistic electron beam injection

    International Nuclear Information System (INIS)

    Tanaka, M.; Sato, T.

    1985-01-01

    A new implicit macroscale electromagnetic particle simulation code (MARC) which allows a large scale length and a time step in multi-dimensions is described. Finite mass electrons and ions are used with relativistic version of the equation of motion. The electromagnetic fields are solved by using a complete set of Maxwell equations. For time integration of the field equations, a decentered (backward) finite differencing scheme is employed with the predictor - corrector method for small noise and super-stability. It is shown both in analytical and numerical ways that the present scheme efficiently suppresses high frequency electrostatic and electromagnetic waves in a plasma, and that it accurately reproduces low frequency waves such as ion acoustic waves, Alfven waves and fast magnetosonic waves. The present numerical scheme has currently been coded in three dimensions for application to a new tokamak current-drive method by means of relativistic electron beam injection. Some remarks of the proper macroscale code application is presented in this paper

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

    International Nuclear Information System (INIS)

    Aleixo, Poliana Carolina; Junior, Dario Santos; Tomazelli, Andrea Cristina; Rufini, Iolanda A.; Berndt, Harald; Krug, Francisco Jose

    2004-01-01

    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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Transient phenomena during electron beam injection in the Saclay 45 MeV accelerator; Regimes transitoires a l'injection du faisceau d'electrons dans l'accelerateur 45 MeV de Saclay

    Energy Technology Data Exchange (ETDEWEB)

    Marcou, J.; Papiernik, A.; Wartski, L. [Institut d' Electronique Fondamentale de la Faculte des Sciences d' Orsay, 91 (France); Bolore, M.; Filippi, G.; Roland, S. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-07-01

    The principal features of transient phenomena, when electron beams are injected in a constant field linear accelerator, are analysed and interpreted by the use of a simple theory. Influence of these transient phenomena on the energy of accelerated particles is observed using a relatively precise method. For very large beam currents, non linear phenomena due to beam deformation can be exhibited, when the electron velocity is not exactly equal to the light velocity. (author) [French] Les principaux aspects des regimes transitoires a l'injection du faisceau d'electrons dans un accelerateur lineaire a champ constant sont mis en evidence et interpretes a l'aide d'une theorie simplifiee. L'influence de ces regimes transitoires sur l'energie des particules accelerees est observee par une methode relativement precise. Lorsque le courant faisceau est tres eleve, on montre que des phenomenes non lineaires dus a la deformation du courant peuvent apparaitre si la vitesse du faisceau n'est pas suffisamment proche de la vitesse de la lumiere. (auteur)

  12. Injection of 40 kHz-modulated electron beam from the satellite: I. Beam-plasma interaction near the linear stability boundary

    Czech Academy of Sciences Publication Activity Database

    Baranets, N.; Ruzhin, Y.; Dokukin, V.; Ciobanu, M.; Rothkaehl, H.; Kiraga, A.; Vojta, Jaroslav; Šmilauer, Jan; Kudela, K.

    2017-01-01

    Roč. 59, č. 12 (2017), s. 2951-2968 ISSN 0273-1177 Institutional support: RVO:68378289 Keywords : beam-plasma interaction * space charge beam waves * pump wave * weak-coupling prediction Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 1.401, year: 2016 http://www.sciencedirect.com/science/article/pii/S0273117717302181

  13. Injection of 40 kHz-modulated electron beam from the satellite: I. Beam-plasma interaction near the linear stability boundary

    Czech Academy of Sciences Publication Activity Database

    Baranets, N.; Ruzhin, Yu.; Dokukin, V.; Ciobanu, M.; Rothkaehl, H.; Kiraga, A.; Vojta, Jaroslav; Šmilauer, Jan; Kudela, K.

    2017-01-01

    Roč. 59, č. 12 (2017), s. 2951-2968 ISSN 0273-1177 Institutional support: RVO:68378289 Keywords : energy waves * instability * system * beam-plasma interaction * space charge beam waves * pump wave * weak-coupling prediction Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 1.401, year: 2016 http://www.sciencedirect.com/science/article/pii/S0273117717302181

  14. Proof of the nonexistence of a linear solution for the CR2 injection region of the CLIC drive beam

    CERN Document Server

    Apsimon, Robert

    2014-01-01

    In this paper we present a mathematical proof to show that there exists no linear system of optics which can simultaneously close an orbit bump and correct the dispersion in the CR2 injection region. Due to the requirements of the CR2 injection region, several different trajectories will exist through the injection region which are off-axis; therefore the orbit and dispersion functions need to be corrected. In this paper, we determine the properties of a hypothetical linear lattice which is capable of closing the orbit and dispersion functions and then show that the resulting solutions are either unphysical or trivial. Geneva.

  15. Non-linear beam dynamics tests in the LHC: measurement of intensity decay for probing dynamic aperture at injection

    CERN Document Server

    Cettour Cave, S; Giovannozzi, M; Ludwig, M; MacPherson, A; Redaelli, S; Roncarolo, F; Solfaroli Camillocci, M; Venturini Delsolaro, W

    2013-01-01

    For a second year in a row dynamic aperture experiments have been performed at the LHC. These studies have been carried out by two teams following alternative techniques: On Beam 1 a novel approach has been tested which heats the beam until the emittance becomes large, and derives the dynamic aperture from beam losses assuming an inverse logarithm model for the time-dependence of the intensity. On Beam 2, the traditional approach of sampling the dynamic aperture with large amplitude kicks has been pursued [1]. In 2011, considerable progress was made and impressive results have been reported. In 2012 a further Machine Development (MD) session was scheduled during which both teams have benefited from an improved availability of the beams and more optimal performance of the instrumentation. Observations and analysis are presented as two MD reports of the LHC dynamic aperture experiment MD. This note describes the observations made on Beam 1, when the strength of the spool pieces have been varied. The key quantit...

  16. Beam loss caused by edge focusing of injection bump magnets and its mitigation in the 3-GeV rapid cycling synchrotron of the Japan Proton Accelerator Research Complex

    Directory of Open Access Journals (Sweden)

    H. Hotchi

    2016-01-01

    Full Text Available In the 3-GeV rapid cycling synchrotron of the Japan Proton Accelerator Research Complex, transverse injection painting is utilized not only to suppress space-charge induced beam loss in the low energy region but also to mitigate foil scattering beam loss during charge-exchange injection. The space-charge induced beam loss is well minimized by the combination of modest transverse painting and full longitudinal painting. But, for sufficiently mitigating the foil scattering part of beam loss, the transverse painting area has to be further expanded. However, such a wide-ranging transverse painting had not been realized until recently due to beta function beating caused by edge focusing of pulsed injection bump magnets during injection. This beta function beating additionally excites random betatron resonances through a distortion of the lattice superperiodicity, and its resultant deterioration of the betatron motion stability causes significant extra beam loss when expanding the transverse painting area. To solve this issue, we newly installed pulse-type quadrupole correctors to compensate the beta function beating. This paper presents recent experimental results on this correction scheme for suppressing the extra beam loss, while discussing the beam loss and its mitigation mechanisms with the corresponding numerical simulations.

  17. 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.

  18. 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)

    Fiorucci, Donatella

    2015-01-01

    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)

  19. THE RHIC INJECTION SYSTEM.

    Energy Technology Data Exchange (ETDEWEB)

    FISCHER,W.; GLENN,J.W.; MACKAY,W.W.; PTITSIN,V.; ROBINSON,T.G.; TSOUPAS,N.

    1999-03-29

    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. We describe our 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.

  20. Study of gamma-ray emission by proton beam interaction with injected Boron atoms for future medical imaging applications

    Czech Academy of Sciences Publication Activity Database

    Petringa, G.; Cirrone, G.A.P.; Caliri, C.; Cuttone, G.; Giuffrida, Lorenzo; Larosa, G.; Manna, R.; Manti, L.; Marchese, V.; Marchetta, C.; Margarone, Daniele; Milluzzo, G.; Picciotto, A.; Romano, F.; Romano, F.P.; Russo, A.D.; Russo, G.; Santonocito, D.; Scuderi, Valentina

    2017-01-01

    Roč. 12, Mar (2017), s. 1-10, č. článku C03049. ISSN 1748-0221 R&D Projects: GA MŠk EF15_008/0000162; GA MŠk LQ1606 Grant - others:ELI Beamlines(XE) CZ.02.1.01/0.0/0.0/15_008/0000162 Institutional support: RVO:68378271 Keywords : Instrumentation for particle-beam therapy * spallation source targets * radioisotope production * neutrino and muon sources Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 1.220, year: 2016

  1. Time-resolved C-arm cone beam CT angiography (TR-CBCTA) imaging from a single short-scan C-arm cone beam CT acquisition with intra-arterial contrast injection

    Science.gov (United States)

    Li, Yinsheng; Garrett, John W.; Li, Ke; Wu, Yijing; Johnson, Kevin; Schafer, Sebastian; Strother, Charles; Chen, Guang-Hong

    2018-04-01

    Time-resolved C-arm cone-beam CT (CBCT) angiography (TR-CBCTA) images can be generated from a series of CBCT acquisitions that satisfy data sufficiency condition in analytical image reconstruction theory. In this work, a new technique was developed to generate TR-CBCTA images from a single short-scan CBCT data acquisition with contrast media injection. The reconstruction technique enabling this application is a previously developed image reconstruction technique, synchronized multi-artifact reduction with tomographic reconstruction (SMART-RECON). In this new application, the acquired short-scan CBCT projection data were sorted into a union of several sub-sectors of view angles and each sub-sector of view angles corresponds to an individual image volume to be reconstructed. The SMART-RECON method was then used to jointly reconstruct all of these individual image volumes under two constraints: (1) each individual image volume is maximally consistent with the measured cone-beam projection data within the corresponding view angle sector and (2) the nuclear norm of the image matrix is minimized. The difference between these reconstructed individual image volumes is used to generated the desired subtracted angiograms. To validate the technique, numerical simulation data generated from a fractal tree angiogram phantom were used to quantitatively study the accuracy of the proposed method and retrospective in vivo human subject studies were used to demonstrate the feasibility of generating TR-CBCTA in clinical practice.

  2. 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

  3. 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.

  4. Incident neutron spectra on the first wall and their application to energetic ion diagnostics in beam-injected deuterium-tritium tokamak plasmas

    Science.gov (United States)

    Sugiyama, S.; Matsuura, H.; Uchiyama, D.

    2017-09-01

    A diagnostic method for small non-Maxwellian tails in fuel-ion velocity distribution functions is proposed; this method uses the anisotropy of neutron emissions, and it is based on the numerical analysis of the incident fast neutron spectrum on the first wall of a fusion device. Neutron energy spectra are investigated for each incident position along the first wall and each angle of incidence assuming an ITER-like deuterium-tritium plasma; it is heated by tangential-neutral-beam injection. Evaluating the incident neutron spectra at all wall positions and angles of incidence enables the selective measurement of non-Gaussian components in the neutron emission spectrum for energetic ion diagnostics; in addition, the optimal detector position and orientation can be determined. At the optimal detector position and orientation, the ratio of non-Gaussian components to the Gaussian peak can be two orders of magnitude greater than the ratio in the neutron emission spectrum. This result can improve the accuracy of energetic ion diagnostics in plasmas when small, anisotropic non-Maxwellian tails are formed in fuel ion velocity distribution functions. We focus on the non-Gaussian components greater than 14 MeV, where the effect of the background noise (i.e., slowing-down neutrons by scattering throughout the machine structure) can be ignored.

  5. Beam diagnostics

    International Nuclear Information System (INIS)

    Bogaty, J.; Clifft, B.E.; Zinkann, G.P.; Pardo, R.C.

    1995-01-01

    The ECR-PII injector beam line is operated at a fixed ion velocity. The platform high voltage is chosen so that all ions have a velocity of 0.0085c at the PII entrance. If a previous tune configuration for the linac is to be used, the beam arrival time must be matched to the previous tune as well. A nondestructive beam-phase pickup detector was developed and installed at the entrance to the PII linac. This device provides continuous phase and beam current information and allows quick optimization of the beam injected into PII. Bunches traverse a short tubular electrode thereby inducing displacement currents. These currents are brought outside the vacuum interface where a lumped inductance resonates electrode capacitance at one of the bunching harmonic frequencies. This configuration yields a basic sensitivity of a few hundred millivolts signal per microampere of beam current. Beam-induced radiofrequency signals are summed against an offset frequency generated by our master oscillator. The resulting kilohertz difference frequency conveys beam intensity and bunch phase information which is sent to separate processing channels. One channel utilizes a phase locked loop which stabilizes phase readings if beam is unstable. The other channel uses a linear full wave active rectifier circuit which converts kilohertz sine wave signal amplitude to a D.C. voltage representing beam current. A prototype set of electronics is now in use with the detector and we began to use the system in operation to set the arrival beam phase. A permanent version of the electronics system for the phase detector is now under construction. Additional nondestructive beam intensity and phase monitors at the open-quotes Boosterclose quotes and open-quotes ATLASclose quotes linac sections are planned as well as on some of the high-energy beam lines. Such a monitor will be particularly useful for FMA experiments where the primary beam hits one of the electric deflector plates

  6. 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.

  7. 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)

  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. 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.

  10. 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.

  11. Injection and temporary capture of a charged particle beam in an open magnetic configuration. Optimization of the configuration. Case of cylindrical symmetry: A mirror machine; Etude de l'injection et de la capture temporaire d'un faisceau de particules chargees dans une configuration magnetique ouverte. Optimisation de la configuration. Cas de la symetrie de revolution: Machine a miroirs

    Energy Technology Data Exchange (ETDEWEB)

    Capdequi-Peyranere, P. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1966-12-01

    A study has been made of a new method of transverse injection of charged particles into a magnetic mirror configuration. This injection scheme permits the penetration and temporary capture by non-adiabatic effect of a particle beam of approximately 1 cm{sup 2} cross-section. A theoretical study of the injection and capture is made in the approximation that space charge is negligible. The original programs for IBM 7094 computer calculations are described; these programs were used to obtain an optimization of the configuration. The results of a statistical numerical study of the optimum configuration are then given. This study indicates that, if the energy of the particles of the beam is about 1 per cent greater than a minimum penetration energy, the entire beam can be captured with an average capture length of 100 meters (50 reflections between the two mirrors). If the energy is about 4 per cent greater than the minimum penetration energy, the capture length is reduced to 40 meters. We have studied the distribution of energy transverse and longitudinal with the magnetic field for the population of captured particles. For the cases of injected molecular hydrogen ions or heavy CH{sub 4}{sup +} ions, a study is made of the capture time of protons resulting from the dissociation of the ions by collisions with the neutral gas. Finally, we describe a model experiment using electrons designed to provide an experimental verification of the capture of the primary beam. (author) [French] On etudie un nouveau schema d'injection transversale de particules chargees dans une configuration magnetique a miroirs. Ce mode d'injection permet la penetration et la capture temporaire par effet non adiabatique d'un faisceau de particules presentant une section de l'ordre de 1 cm{sup 2}. Une etude theorique du probleme de l'injection et de la capture est faite en supposant la charge d'espace negligeable. On decrit des programmes originaux de calcul sur

  12. Perturbative studies of toroidal momentum transport using neutral beam injection modulation in the Joint European Torus: Experimental results, analysis methodology, and first principles modeling

    DEFF Research Database (Denmark)

    Mantica, P.; Tala, T.; Ferreira, J.S.

    2010-01-01

    Perturbative experiments have been carried out in the Joint European Torus [Fusion Sci. Technol. 53(4) (2008)] in order to identify the diffusive and convective components of toroidal momentum transport. The torque source was modulated either by modulating tangential neutral beam power...... or by modulating in antiphase tangential and normal beams to produce a torque perturbation in the absence of a power perturbation. The resulting periodic perturbation in the toroidal rotation velocity was modeled using time-dependent transport simulations in order to extract empirical profiles of momentum...

  13. Beam Techniques - Beam Control and Manipulation

    Energy Technology Data Exchange (ETDEWEB)

    Minty, Michiko G

    2003-04-24

    We describe commonly used strategies for the control of charged particle beams and the manipulation of their properties. Emphasis is placed on relativistic beams in linear accelerators and storage rings. After a brief review of linear optics, we discuss basic and advanced beam control techniques, such as transverse and longitudinal lattice diagnostics, matching, orbit correction and steering, beam-based alignment, and linac emittance preservation. A variety of methods for the manipulation of particle beam properties are also presented, for instance, bunch length and energy compression, bunch rotation, changes to the damping partition number, and beam collimation. The different procedures are illustrated by examples from various accelerators. Special topics include injection and extraction methods, beam cooling, spin transport and polarization.

  14. Simulation of distributed-emission and injected-beam crossed-field amplifiers. Part 2: The crossed-field electron gun

    Science.gov (United States)

    MacGregor, D. M.; Fontana, T. P.; Rowe, J. E.

    1980-04-01

    Numerical models developed for the crossed-field electron gun predict the current and the beam shape and stability for varied voltages or magnetic field. These programs use a deformable triangular mesh to reproduce the realistic electrode boundaries. A static iterative analysis predicts beam currents about 5 percent higher than measured for a short Kino gun, but is not stable for long cathodes with returning electrodes. However, the alternative time-dependent method predicts a stable, well-defined beam in both cases. Excess shot noise in a long-cathode crossed-field gun is believed to be due to cycloiding electrons which return to the cathode from well beyond the potential minimum. Of three theories compared here, only the Ho and Van Duzer model includes these electrons and predicts an instability. With added shot noise the computer simulation may be capable of reproducing the effect. Experimental measurements have been obtained by subcontract for a Northrop gridded crossed-field gun. The two dimensional time-dependent analysis, which ignores the grids, predicts the beam current with good order-of-magnitude agreement.

  15. Testosterone Injection

    Science.gov (United States)

    ... typical male characteristics. Testosterone injection works by supplying synthetic testosterone to replace the testosterone that is normally ... as a pellet to be injected under the skin.Testosterone injection may control your symptoms but will ...

  16. 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.

  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)

    Ahn, H.E.

    1992-10-01

    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. Injection diagnostic procedures for the Chalk River Superconducting Cyclotron

    International Nuclear Information System (INIS)

    Davies, W.G.

    1984-01-01

    The beam diagnostics system for the injection beam line for the Chalk River Tandem Accelerator - Superconducting Cyclotron is described. The system has been designed such that simple and easily interpreted measurements can be made for operational beam monitoring as well as for the complete 6-dimensional beam phase-space determinations required for beam development

  19. 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...

  20. Cefoxitin Injection

    Science.gov (United States)

    ... injection is used to treat infections caused by bacteria including pneumonia and other lower respiratory tract (lung) infections; and urinary tract, abdominal (stomach area), female reproductive organs, blood, ... by killing bacteria.Antibiotics such as cefoxitin injection will not work ...

  1. Golimumab Injection

    Science.gov (United States)

    ... 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 colorless ...

  2. Doxycycline Injection

    Science.gov (United States)

    ... may have been exposed to anthrax in the air. Doxycycline injection is in a class of medications ... decrease the effectiveness of hormonal contraceptives (birth control pills, patches, rings, or injections). Talk to your doctor ...

  3. Abaloparatide Injection

    Science.gov (United States)

    ... injection may cause osteosarcoma (bone cancer) in laboratory rats. It is not known whether abaloparatide injection increases ... too have too much calcium in the blood, hyperparathyroidism (condition in which the body produces too much ...

  4. 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 ...

  5. Doripenem Injection

    Science.gov (United States)

    ... injection is in a class of medications called carbapenem antibiotics. It works by killing bacteria.Antibiotics such ... if you are allergic to doripenem injection; other carbapenem antibiotics such as imipenem/cilastatin (Primaxin) or meropenem ( ...

  6. Ceftriaxone Injection

    Science.gov (United States)

    Ceftriaxone injection is used to treat certain infections caused by bacteria such as gonorrhea (a sexually transmitted ... skin, urinary tract, blood, bones, joints, and abdomen. Ceftriaxone injection is also sometimes given before certain types ...

  7. Nalbuphine Injection

    Science.gov (United States)

    ... injection is in a class of medications called opioid agonist-antagonists. It works by changing the way ... suddenly stop using nalbuphine injection, you may experience withdrawal symptoms including restlessness; teary eyes; runny nose; yawning; ...

  8. Naltrexone Injection

    Science.gov (United States)

    ... Videos & Tools Español You Are Here: Home → Drugs, Herbs and Supplements → Naltrexone Injection URL of this page: ... become depressed and sometimes try to harm or kill themselves. Receiving naltrexone injection does not decrease the ...

  9. 160 MeV $H^-$ Injection into the CERN PSB

    CERN Document Server

    Weterings, W; Borburgh, J; Fowler, T; Gerigk, F; Goddard, B; Hanke, K; Martini, M; Sermeus, L

    2007-01-01

    The H- beam from the proposed LINAC4 will be injected into the four existing rings of the PS Booster at 160 MeV. A substantial upgrade of the injection region is required, including the modification of the beam distribution system and the construction of a new H- injection system. This paper discusses beam dynamics and hardware requirements and presents the results of optimisation studies of the injection process for different beam characteristics and scenarios. The resulting conceptual design of the injection region is presented, together with the main hardware modifications and performance specifications.

  10. 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

  11. Terascale Beam-Beam Simulations for Tevatron, RHIC and LHC

    Energy Technology Data Exchange (ETDEWEB)

    Qiang, J.

    2005-05-16

    In this paper, we report on recent advances in terascale simulations of the beam-beam interaction in Tevatron, RHIC and LHC.Computational methods for self consistent calculation of beam-beam forces are reviewed. New method for solving the two-dimensional Poisson equation with open boundary conditions is proposed and tested. This new spectral-finite difference method is a factor of four faster than the widely used FFT based Green function method for beam-beam interaction on axis. We also present applications to the study of antiproton losses during the injection stage at Tevatron, to the study of multiple bunch coherent beam-beam modes at RHIC, and to the study of beam-beam driven emittance growth at LHC.

  12. Terascale Beam-Beam Simulations for Tevatron, RHIC and LHC

    International Nuclear Information System (INIS)

    Qiang, J.

    2005-01-01

    In this paper, we report on recent advances in terascale simulations of the beam-beam interaction in Tevatron, RHIC and LHC.Computational methods for self consistent calculation of beam-beam forces are reviewed. New method for solving the two-dimensional Poisson equation with open boundary conditions is proposed and tested. This new spectral-finite difference method is a factor of four faster than the widely used FFT based Green function method for beam-beam interaction on axis. We also present applications to the study of antiproton losses during the injection stage at Tevatron, to the study of multiple bunch coherent beam-beam modes at RHIC, and to the study of beam-beam driven emittance growth at LHC

  13. Design analysis and performance evaluation of a two-dimensional camera for accelerated positron-emitter beam injection by computer simulation

    International Nuclear Information System (INIS)

    Llacer, J.; Chatterjee, A.; Batho, E.K.; Poskanzer, J.A.

    1982-05-01

    The characteristics and design of a high-accuracy and high-sensitivity 2-dimensional camera for the measurement of the end-point of the trajectory of accelerated heavy ion beams of positron emitter isotopes are described. Computer simulation methods have been used in order to insure that the design would meet the demanding criteria of ability to obtain the location of the centroid of a point source in the X-Y plane with errors smaller than 1 mm, with an activity of 100 nanoCi, in a counting time of 5 sec or less. A computer program which can be developed into a general purpose analysis tool for a large number of positron emitter camera configurations is described in its essential parts. The validation of basic simulation results with simple measurements is reported, and the use of the program to generate simulated images which include important second order effects due to detector material, geometry, septa, etc. is demonstrated. Comparison between simulated images and initial results with the completed instrument shows that the desired specifications have been met

  14. Laser beam shaping techniques

    Energy Technology Data Exchange (ETDEWEB)

    DICKEY,FRED M.; WEICHMAN,LOUIS S.; SHAGAM,RICHARD N.

    2000-03-16

    Industrial, military, medical, and research and development applications of lasers frequently require a beam with a specified irradiance distribution in some plane. A common requirement is a laser profile that is uniform over some cross-section. Such applications include laser/material processing, laser material interaction studies, fiber injection systems, optical data image processing, lithography, medical applications, and military applications. Laser beam shaping techniques can be divided into three areas: apertured beams, field mappers, and multi-aperture beam integrators. An uncertainty relation exists for laser beam shaping that puts constraints on system design. In this paper the authors review the basics of laser beam shaping and present applications and limitations of various techniques.

  15. Construction of tangential injection NBI system

    International Nuclear Information System (INIS)

    Ohga, Tokumichi; Akino, Noboru; Ebisawa, Noboru

    1995-09-01

    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)

  16. Optical Injection into Laser Wake Field Accelerators

    CERN Document Server

    Cary, John R; Esarey, Eric; Geddes, Cameron G R; Giacone, Rodolfo; Leemans, Wim; Nieter, Chet

    2005-01-01

    The accelerating gradient of laser-generated wake fields in plasmas can be orders of magnitude greater than the gradients obtainable in traditional, rf structures. One of the hurdles to overcome on the road to practical utilization of said plasma wake fields for production of high energy particles is the creation of quality beams having significant charge, low emittance, and narrow energy spread. To generate appropriate beams, various injection methods have been proposed. Injection by conventional means of beam prepartion using conventional technology is very difficult, as the accelerating buckets are only tens of microns long. Therefore, the field has turned to all-optical injection schemes, which include injection by colliding pulses, plasma ramps, wave breaking, and self-trapping through pulse evolution. This talk will review the various concepts proposed for injection, including plasma ramps, colliding pulses, and self trapping. The results of simulations and experiments will be discussed along with propo...

  17. Cefazolin Injection

    Science.gov (United States)

    ... is used to treat certain infections caused by bacteria including skin, bone, joint, genital, blood, heart valve, respiratory tract (including pneumonia), biliary tract, and urinary tract infections. Cefazolin injection ...

  18. Atezolizumab Injection

    Science.gov (United States)

    ... is in a class of medications called monoclonal antibodies. It works by blocking the action of a ... infection breath that smells fruity slowed, fast or irregular heartbeat Atezolizumab injection may cause other side effects. ...

  19. Cidofovir Injection

    Science.gov (United States)

    Cidofovir injection is used along with another medication (probenecid) to treat cytomegaloviral retinitis (CMV retinitis) in people ... body's response to the medication.You must take probenecid tablets by mouth with each dose of cidofovir. ...

  20. Acyclovir Injection

    Science.gov (United States)

    ... It is also used to treat first-time genital herpes outbreaks (a herpes virus infection that causes sores ... in the body. Acyclovir injection will not cure genital herpes and may not stop the spread of genital ...

  1. Alirocumab Injection

    Science.gov (United States)

    ... further decrease the amount of low-density lipoprotein (LDL) cholesterol ('bad cholesterol') in the blood. Alirocumab injection is ... antibodies. It works by blocking the production of LDL cholesterol in the body to decrease the amount of ...

  2. Pegloticase Injection

    Science.gov (United States)

    ... doctor if you have glucose-6-phosphate dehydrogenase (G6PD) deficiency (an inherited blood disease). Your doctor may test you for G6PD deficiency before you start to receive pegloticase injection. If ...

  3. Risperidone Injection

    Science.gov (United States)

    ... of interest in life, and strong or inappropriate emotions). Risperidone extended-release injection is used alone or ... during your treatment: extreme thirst, frequent urination, extreme hunger, blurred vision, or weakness. It is very important ...

  4. Olanzapine Injection

    Science.gov (United States)

    ... of interest in life, and strong or inappropriate emotions). Olanzapine injection is used to treat episodes of ... during your treatment: extreme thirst, frequent urination, extreme hunger, blurred vision, or weakness. It is very important ...

  5. Tacrolimus Injection

    Science.gov (United States)

    ... in people who have received kidney, liver, or heart transplants. Tacrolimus injection should only be used by people ... or nurse will watch you closely during the first 30 minutes of your treatment and then will ...

  6. Omalizumab Injection

    Science.gov (United States)

    ... injection is used to decrease the number of asthma attacks (sudden episodes of wheezing, shortness of breath, and ... about how to treat symptoms of a sudden asthma attack. If your asthma symptoms get worse or if ...

  7. Daclizumab Injection

    Science.gov (United States)

    ... neck, armpits, or groin; diarrhea; bloody stools; stomach pain; or any new, unexplained symptom affecting any part of your body.Because of the risks with this medication, daclizumab injection is available only through a special ...

  8. Temozolomide Injection

    Science.gov (United States)

    ... balance or coordination fainting dizziness hair loss insomnia memory problems pain, itching, swelling, or redness in the place where the medication was injected changes in vision Some side effects can be serious. If you ...

  9. Moxifloxacin Injection

    Science.gov (United States)

    ... tendon area, or inability to move or to bear weight on an affected area.Using moxifloxacin injection ... muscle weakness) and cause severe difficulty breathing or death. Tell your doctor if you have myasthenia gravis. ...

  10. Delafloxacin Injection

    Science.gov (United States)

    ... a tendon area, or inability to move or bear weight on an affected area.Using delafloxacin injection ... muscle weakness) and cause severe difficulty breathing or death. Tell your doctor if you have myasthenia gravis. ...

  11. Levofloxacin Injection

    Science.gov (United States)

    ... tendon area, or inability to move or to bear weight on an affected area.Using levofloxacin injection ... muscle weakness) and cause severe difficulty breathing or death. Tell your doctor if you have myasthenia gravis. ...

  12. Ciprofloxacin Injection

    Science.gov (United States)

    ... a tendon area, or inability to move or bear weight on an affected area.Using ciprofloxacin injection ... muscle weakness) and cause severe difficulty breathing or death. Tell your doctor if you have myasthenia gravis. ...

  13. Butorphanol Injection

    Science.gov (United States)

    ... Butorphanol is in a class of medications called opioid agonist-antagonists. It works by changing the way ... suddenly stop using butorphanol injection, you may experience withdrawal symptoms such as nervousness, agitation, shakiness, diarrhea, chills, ...

  14. Haloperidol Injection

    Science.gov (United States)

    ... of interest in life, and strong or inappropriate emotions). Haloperidol injection is also used to control motor ... and the laboratory. Your doctor may order certain lab tests to check your body's response to haloperidol ...

  15. Ketorolac Injection

    Science.gov (United States)

    ... of ketorolac by intravenous (into a vein) or intramuscular (into a muscle) injection in a hospital or ... You can also visit the Food and Drug Administration (FDA) website (http://www.fda.gov/Drugs/DrugSafety/ ...

  16. eRHIC Beam Scrubbing

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, S. Y. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2017-06-22

    We propose using beam scrubbing to mitigate the electron cloud e ect in the eRHIC. The bunch number is adjusted below the heat load limit, then it increases with the reduced secondary electron yield resulted from the beam scrubbing, up to the design bunch number. Since the electron density threshold of beam instability is lower at the injection, a preliminary injection scrubbing should go rst, where large chromaticity can be used to keep the beam in the ring for scrubbing. After that, the beam can be ramped to full energy, allowing physics scrubbing. Simulations demonstrated that with beam scrubbing in a reasonable period of time, the eRHIC baseline design is feasible.

  17. Injection into LHC of bunches at 25 ns spacing

    CERN Document Server

    Goddard, B; Baglin, V; Bartmann, W; Bartosik, H; Baudrenghien, P; Bracco, C; Bregliozzi, G; Claudet, S; Cornelis, K; Drosdal, L; Höfle, W; Jacquet, D; Jensen, L; Jimenez, JM; Kain, V; Lanza, G; Li, K; Meddahi, M; Metral, E; Rumolo, G; Salvant, B; Shaposhnikova, E; Tavian, L; Uythoven, J; Valuch, D; Venturini, W; Wenninger, J

    2011-01-01

    The objective of the MD was the injection into LHC of batches of nominal intensity bunches at 25 ns spacing, with setting up of the relevant machine systems and first observations of beam characteristics and identification of potential issues. During the test, the beams were setup in the SPS and both transfer lines, and trains of 24 bunches at 25 ns spacing were injected into LHC for both beams. A total of 216b per beam were accumulated (9 injections), limited only by the time available. In this note observations are presented on setting up of the lines, beam losses at injection, beam instrumentation performance, damper, RF capture, vacuum pressures, beam screen temperatures, bunch emittances and lifetimes. Some conclusions are drawn and suggestions for future MD discussed.

  18. SNS Injection and Extraction Devices

    CERN Document Server

    Raparia, Deepak

    2005-01-01

    The Spallation Neutron Source (SNS) is a second generation pulsed neutron source (1.5 MW) and is presently in the sixth year of a seven-year construction cycle at Oak Ridge National Laboratory. The operation of the facility will begin in 2006. The most stringent requirement for the SNS accelerator complex is to allow hands-on maintenance. Operational experiences show that the most losses occur in the injection and extraction. SNS accumulator ring injection and extraction has been design with grate care to reduce uncontrolled losses. Injection systems consist of fast programmable kicker magnets and DC dump magnets to paint the beam in transverse phase space. Extraction systems consist of fast kicker magnets and a Lamberton magnet to extract beam in single turn. Paper will discuss design, construction and testing of these devices.

  19. 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 (< 1E+06 nm³), often isolated pores are much more compact and show higher shape factors (G) up to 0.03. WMI in combination with BIB-SEM, down to a resolution of ~ 50 nm² pixel-size, indicates an interconnected porosity fraction of ~ 80 %, of a total measured 2D porosity of ~ 20 %. Determining and distinguishing between pore bodies and pore throats enables us to compare 3D FIB-SEM pore

  20. 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.

  1. Injection and lessons for 2012

    International Nuclear Information System (INIS)

    Bracco, C.; Barnes, M.J.; Bartmann, W.; Cornelis, K.; Drosdal, L.N.; Goddard, B.; Kain, V.; Meddahi, M.; Mertens, V.; Uythoven, J.

    2012-01-01

    Injection of 144 bunches into the LHC became fully operational during the 2011 run and one nominal injection of 288 bunches was accomplished. Several mitigation solutions were put in place to minimise losses from the Transfer Line (TL) collimators and losses from kicking de-bunched beam during injection. Nevertheless, shot-by- shot and bunch-by-bunch trajectory variations, as well as long terms drifts, were observed and required a regular re-steering of the TL implying a non negligible amount of time spent for injection setup. Likely sources of instability have been identified (i.e. MKE and MSE ripples) and possible cures to optimise 2012 operation are presented. Well defined references for TL steering will be defined in a more rigorous way in order to allow a more straightforward and faster injection setup. Encountered and potential issues of the injection system, in particular the injection kickers MKI, are discussed also in view of injections with a higher number of bunches. (authors)

  2. Injection and lessons for 2012

    CERN Document Server

    Bracco, C; Bartmann, W; Cornelis, K; Drosdal, L N; Goddard, B; Kain, V; Meddahi, M; Mertens, V; Uythoven, J

    2012-01-01

    Injection of 144 bunches into the LHC became fully operational during the 2011 run and a nominal injection of 288 bunches was accomplished during MD time. Several mitigation solutions were put in place to minimise losses from the transfer line (TL) collimators and losses from kicking debunched beam during injection. Nevertheless, shot-by-shot and bunch-by-bunch trajectory variations, as well as long terms drifts, were observed and required a regular resteering of the TL implying a non negligible amount of time spent for injection setup. Likely sources of instability have been identified (i.e. MKE and MSE ripples) and possible cures to optimise 2012 operation are presented. Well defined references for TL steering will be defined in a more rigorous way in order to allow a more straightforward and faster injection setup. Encountered and potential issues of the injection system, in particular the injection kickers MKI, are discussed also in view of injections with a higher number of bunches.

  3. Electron beam transport

    International Nuclear Information System (INIS)

    Rudjak, Yu.V.; Vladyko, V.B.

    1993-01-01

    The electron beam transport in ion channel has been investigated. The influence of the external longitudinal magnetic field and self beam magnetic field on the charge neutralization process was defined. Beam head erosion under channel is curved or the availability of transverse external magnetic field was numerically simulated. The numerical investigation of the ion-hose instability was performed. The conditions, when as a result of ion-hose instability development may be coming out of the channel by beam tail, were founded. It was shown, that supplementary creation of plasma by electron beam and ions did not lead to the reduction of ion-hose instability. Sufficient slowing down of ion-hose instability development could be achieved if betatron length increased to impulse tail. In the case of a weak initial nonsymmetrical perturbation, sausage instability was investigated. Numerical simulation showed that this instability could lead to beam radius increasing in order. The electron beam guiding by low conductive plasma channel was considered. The attractive force of beam to this channel under nonsymmetrical injection was defined analytically

  4. Calculation of injection and extraction orbits for the IPCR SSC

    International Nuclear Information System (INIS)

    Goto, A.; Yano, Y.; Kishida, N.; Nakanishi, N.; Wada, T.

    1982-01-01

    Calculations of beam trajectories in the injection and extraction systems for the IPCR SSC were done and the characteristics of those elements were determined. Beam centering for single turn extraction by use of first harmonic fields were also studied. The rather simple conditions at the injection point for a well-centered acceleration orbit are also discussed

  5. Plasma Injection Schemes for Laser-Plasma Accelerators

    OpenAIRE

    Faure, J.

    2016-01-01

    Plasma injection schemes are crucial for producing high-quality electron beams in laser-plasma accelerators. This article introduces the general concepts of plasma injection. First, a Hamiltonian model for particle trapping and acceleration in plasma waves is introduced; ionization injection and colliding-pulse injection are described in the framework of this Hamiltonian model. We then proceed to consider injection in plasma density gradients.

  6. Ceftazidime Injection

    Science.gov (United States)

    ... is used to treat certain infections caused by bacteria including pneumonia and other lower respiratory tract (lung) infections; meningitis (infection of the membranes that surround the brain and spinal cord) and ... killing bacteria.Antibiotics such as ceftazidime injection will not work ...

  7. Teduglutide Injection

    Science.gov (United States)

    ... who need additional nutrition or fluids from intravenous (IV) therapy. Teduglutide injection is in a class of medications ... of the ingredients.tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking ...

  8. Dexrazoxane Injection

    Science.gov (United States)

    ... are used to treat or prevent certain side effects that may be caused by chemotherapy medications. Dexrazoxane injection (Zinecard) is used to prevent or decrease heart damage caused by doxorubicin in women who are taking the medication to treat breast cancer that has spread to other parts of the ...

  9. Dulaglutide Injection

    Science.gov (United States)

    ... thyroid carcinoma (MTC; a type of thyroid cancer). Laboratory animals who were given dulaglutide developed tumors, but it ... your doctor will probably tell you not to use dulaglutide injection. If you ... doctor and the laboratory. Your doctor may order certain tests to check ...

  10. Albiglutide Injection

    Science.gov (United States)

    ... thyroid carcinoma (MTC; a type of thyroid cancer). Laboratory animals who were given medications similar to albiglutide developed ... your doctor will probably tell you not to use albiglutide injection. If you ... doctor and the laboratory. Your doctor may order certain tests to check ...

  11. Semaglutide Injection

    Science.gov (United States)

    ... thyroid carcinoma (MTC; a type of thyroid cancer). Laboratory animals who were given semaglutide developed tumors, but it ... your doctor will probably tell you not to use semaglutide injection. If you ... doctor and the laboratory. Your doctor may order certain tests to check ...

  12. Liraglutide Injection

    Science.gov (United States)

    ... thyroid carcinoma (MTC; a type of thyroid cancer). Laboratory animals who were given liraglutide developed tumors, but it ... your doctor will probably tell you not to use liraglutide injection. If you ... doctor and the laboratory. Your doctor may order certain tests to check ...

  13. Exenatide Injection

    Science.gov (United States)

    ... thyroid carcinoma (MTC; a type of thyroid cancer). Laboratory animals who were given exenatide developed tumors, but it ... your doctor will probably tell you not to use exenatide injection. If you ... doctor and the laboratory. Your doctor may order certain tests to check ...

  14. Etoposide Injection

    Science.gov (United States)

    ... used in combination with other medications to treat cancer of the testicles that has not improved or that has worsened after treatment with other medications or radiation therapy. Etoposide injection ... type of lung cancer (small cell lung cancer; SCLC). Etoposide is in ...

  15. Cefepime Injection

    Science.gov (United States)

    ... infection because they have a low number of white blood cells. Cefepime injection is in a class ... In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has ...

  16. Triptorelin Injection

    Science.gov (United States)

    ... puberty too soon, resulting in faster than normal bone growth and development of sexual characteristics) in children 2 years and older. Triptorelin injection is in a class of medications called gonadotropin-releasing hormone (GnRH) agonists. It works by decreasing the amount ...

  17. 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.

  18. 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.

  19. Betatrons with kiloampere beams

    International Nuclear Information System (INIS)

    Peterson, J.M.

    1982-11-01

    Although the magnetic-induction method of acceleration used in the betatron is inherently capable of accelerating intense particle beams to high energy, many beam-instability questions arise when beams in the kilo-ampere range are considered. The intense electromagnetic fields produced by the beam, and by the image currents and charges induced in the surrounding walls, can produce very disruptive effects. Several unstable modes of collective oscillation are possible; the suppression of any one of them usually involves energy spread for Landau damping and careful design of the electrical character of the vacuum chamber. The various design criteria are often mutually incompatible. Space-charge detuning can be severe unless large beam apertures and high-energy injection are used. In order to have an acceptably low degree of space-charge detuning in the acceleration of a 10-kilo-ampere electron beam, for example, an injection energy on the order of 50 MeV seems necessary, in which case the forces due to nearby wall images can have a larger effect than the internal forces of the beam. A method of image compensation was invented for reducing the net image forces; it serves also to decrease the longitudinal beam impedance and thus helps alleviate the longitudinal instability as well. In order to avoid the ion-electron collective instability a vacuum in the range of 10 - 8 torr is required for an acceleration time of 1 millisecond. A multi-ring betatron system using the 50-MeV Advanced Test Accelerator at LLNL as an injector was conceptually designed

  20. Coherent beam-beam effects

    International Nuclear Information System (INIS)

    Chao, A.W.

    1992-01-01

    There are two physical pictures that describe the beam-beam interaction in a storage ring collider: The weak-strong and the strong-strong pictures. Both pictures play a role in determining the beam-beam behavior. This review addresses only the strong-strong picture. The corresponding beam dynamical effects are referred to as the coherent beam-beam effects. Some basic knowledge of the weak-strong picture is assumed. To be specific, two beams of opposite charges are considered. (orig.)

  1. Superresolution beams

    CSIR Research Space (South Africa)

    Ngcobo, S

    2011-11-01

    Full Text Available zones capable of introducing a phase shift of zero or p on the alternately out of phase rings of the TEMp0 beams into a unified phase and then focusing the rectified beam to generate a high resolution beam which has a Gaussian beam intensity distribution...

  2. Monitoring the extracted proton beam at the SPS

    CERN Multimedia

    CERN PhotoLab

    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.

  3. Filamentation of a converging heavy ion beam

    International Nuclear Information System (INIS)

    Lee, E.P.; Buchanan, H.L.; Rosenbluth, M.N.

    1980-01-01

    A major concern in the use of heavy ion beams as igniters in pellet fusion systems is the vulnerability of the beam to the transverse flamentation instability. The undesirable consequence of this mode is the transverse heating of the beam to the extent that convergence on the pellet becomes impossible. This work considers the case of a beam injected into a gas filled reactor vessel, where finite pulse length and propagation distance play an important role in limiting growth. Two geometries are analyzed: a nonconverging case where the radius at injection is nearly equal to the desired radius at the pellet, and a converging case in which the injection radius is large and the beam is pre-focused to converge at the target. It is found that a cold beam will be severely disrupted if the product of the magnetic plasma frequency and the propagation distance is much larger than unity

  4. 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.

  5. Beam-beam and impedance

    CERN Document Server

    White, S.

    2014-07-17

    As two counter-rotating beams interact they can give rise to coherent dipole modes. Under the influence of impedance these coherent beam-beam modes can couple to higher order head-tail modes and lead to strong instabilities. A fully self-consistent approach including beam-beam and impedance was used to characterize this new coupled mode instability and study possible cures such as a transverse damper and high chromaticity.

  6. TORE SUPRA neutral injection system

    International Nuclear Information System (INIS)

    Bayetti, P.; Becherer, R.; Bottiglioni, F.; Jacquot, C.; Jequier, F.; Fumelli, M.; Lotte, P.; Pamela, J.; Sledziewski, Z.

    1989-01-01

    The Neutral Beam Injection on TS consists of three boxes, each housing two injectors. Each of them is designed to accelerate 40 A at 100 kV in D 2 ar 40A at 80 kV in H 2 , in shots of 30 s. The power on the plasma is expected to be 7.5 MW (full energy) and 9 MW (total) for the D-beams; 2.5 MW and 3.8 MW for H-beams. This for a species mix of 0.85 19 m -2 and a transmission efficiency of 0.7. Four injectors are in co and two through another one, and they are tilted of 20 deg from the radial direction. Injectors are designed for the energy recovery of the full energy ions. A prototype line, operated in 1987-88, has given the imput for the demensioning of the present system.First injectors are expected to be operational by the end of 1988. The present contribution describes the injection boxes, injection line, magnetic shielding, electrical circuity and power supplies, control and data acquisition systems, and the Fast Interlock Safety System (FISS). 7 refs.; 6 figs

  7. Relativistic electron beam device

    Science.gov (United States)

    Freeman, J.R.; Poukey, J.W.; Shope, S.L.; Yonas, G.

    1975-07-01

    A design is given for an electron beam device for irradiating spherical hydrogen isotope bearing targets. The accelerator, which includes hollow cathodes facing each other, injects an anode plasma between the cathodes and produces an approximately 10 nanosecond, megajoule pulse between the anode plasma and the cathodes. Targets may be repetitively positioned within the plasma between the cathodes, and accelerator diode arrangement permits materials to survive operation in a fusion power source. (auth)

  8. Automated injection procedure for the CERN intersecting storage rings (ISR)

    CERN Document Server

    Vos, L

    1981-01-01

    The performance of the ISR is critically dependent on the conservation of the transverse beam size. One important source of transverse blow- up for proton beams is injection errors. A two-phase injection procedure is designed to limit these errors to negligible proportions. The first phase, based on the analysis of the first turn beam trajectory, reduces the errors sufficiently to ensure that nearly all of the particles ejected by the CERN-PS will circulate on the ISR injection orbit. The remaining errors are reduced in a second phase based on the accurate measurement of the injection error amplitude, i.e. the amplitude of the coherent betatron oscillation of the injected beam. The residual error causes a blow-up not exceeding a few per cent. The two phases are fully automated using the ISR control computer. (5 refs).

  9. Beam Interlocks for LHC and SPS

    CERN Document Server

    Dinius, A; Gimeno-Vicente, J; Nouchi, P; Puccio, B; Schmidt, R; Wenninger, J

    2003-01-01

    The Large Hadron Collider at CERN (LHC) will operate at 7 TeV/c with a luminosity of 10 cms. This requires two beams with about 3^10 protons/beam, corresponding to a stored energy of about 350 MJ, sufficient to heat and melt 500 kg of copper. Protection of equipment from damage in case of uncontrolled beam losses is challenging. Injection of the beam from the SPS to the LHC could already damage equipment and is only permitted when all LHC systems are correctly prepared. In case of an uncontrolled loss of the circulating LHC beams, it is required to extract the beams into a specially designed target as soon as possible. Beam loss monitors and equipment for hardware surveillance are distributed around the 26 km long accelerator. In case of failures or beam losses, the beam interlock system is informed and sends a dump request to the beam dumping system. The beam interlock system also inhibits injection when the LHC is not ready for beam. In this paper the requirements for the beam interlock system are discussed...

  10. 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.

  11. Beam cooling

    OpenAIRE

    Danared, H

    2006-01-01

    Beam cooling is the technique of reducing the momentum spread and increasing the phase-space density of stored particle beams. This paper gives an introduction to beam cooling and Liouville’s theorem, and then it describes the three methods of active beam cooling that have been proven to work so far, namely electron cooling, stochastic cooling, and laser cooling. Ionization cooling is also mentioned briefly.

  12. Molecular beams

    International Nuclear Information System (INIS)

    Pendelbury, J.M.; Smith, K.F.

    1987-01-01

    Studies with directed collision-free beams of particles continue to play an important role in the development of modern physics and chemistry. The deflections suffered by such beams as they pass through electric and magnetic fields or laser radiation provide some of the most direct information about the individual constituents of the beam; the scattering observed when two beams intersect yields important data about the intermolecular forces responsible for the scattering. (author)

  13. 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...... 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...

  14. Injection envelope matching in storage rings

    International Nuclear Information System (INIS)

    Minty, M.G.; Spence, W.L.

    1995-05-01

    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

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

    International Nuclear Information System (INIS)

    Fuentes Lopez, C.

    2007-01-01

    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

  16. Tuning the beam: a physics perspective on beam diagnostic instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Gulley, Mark S [Los Alamos National Laboratory

    2010-01-01

    In a nutshell, the role of a beam diagnostic measurement is to provide information needed to get a particle beam from Point A (injection point) to Point B (a target) in a useable condition, with 'useable' meaning the right energy and size and with acceptable losses. Specifications and performance requirements of diagnostics are based on the physics of the particle beam to be measured, with typical customers of beam parameter measurements being the accelerator operators and accelerator physicists. This tutorial will be a physics-oriented discussion of the interplay between tuning evolutions and the beam diagnostics systems that support the machine tune. This will include the differences between developing a tune and maintaining a tune, among other things. Practical longitudinal and transverse tuning issues and techniques from a variety of proton and electron machines will also be discussed.

  17. 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.

  18. MEASUREMENTS OF INTRA-BEAM SCATTERING GROWTH TIMES WITH GOLD BEAM BELOW TRANSITION IN RHIC

    International Nuclear Information System (INIS)

    FISCHER, W.; BAI, M.; BLASKIEWICZ, M.; BRENNAN, J.M.; CAMERON, P.; CONNOLLY, R.; LEHRACH, A.; PARZEN, G.; TEPIKIAN, S.; ZENO, K.; VAN ZEIJTS, J.

    2001-01-01

    While RHIC is filled with beam, bunches are stored for up to several minutes at the injection energy before acceleration starts. In gold operation, the RHIC injection energy is below transition. A bunch length increase, and correspondingly an increase in the longitudinal emittance, can lead to particle loss during transition crossing and rebucketing into the storage buckets. The longitudinal growth of gold beams in RHIC at injection is dominated by intra-beam scattering. Measurements of longitudinal growth times are presented and compared with computations

  19. Beam based systems and controls

    CERN Document Server

    Jacquet, D

    2012-01-01

    This presentation will give a review from the operations team of the performance and issues of the beam based systems, namely RF, ADT, beam instrumentation, controls and injection systems. For each of these systems, statistics on performance and availability will be presented with the main issues encountered in 2012. The possible improvements for operational efficiency and safety will be discussed, with an attempt to answer the question "Are we ready for the new challenges brought by the 25ns beam and increased energy after LSI? ".

  20. Operational considerations for the PSB H- Injection System

    CERN Document Server

    Weterings, W; Borburgh, J; Carli, C; Fowler, T; Goddard, B

    2010-01-01

    For the LINAC4 project the PS Booster (PSB) injection system will be upgraded. The 160 MeV Hbeam will be distributed to the 4 superimposed PSB synchrotron rings and horizontally injected by means of an H- charge-exchange system. Operational considerations for the injection system are presented, including expected beam losses from unwanted field stripping of H- and excited H0 and foil scattering, possible injection failure cases and expected stripping foil lifetimes. Loading assumptions for the internal beam dumps are discussed together with estimates of doses on various components.

  1. Intensive Ion Beam In Storage Rings With Electron Cooling

    CERN Document Server

    Korotaev, Yu V; Kamerdjiev, V; Maier, R; Meshkov, I; Noda, K; Prasuhn, D; Sibuya, S; Sidorin, A; Stein, H J; Stockhorst, H; Syresin, E M; Uesugi, T

    2004-01-01

    Results of experimental studies of the electron cooling of a proton beam at COSY (Juelich, Germany) and an ion beam at HIMAC (Chiba, Japan) are presented. Intensity of the ion beam is limited by two general effects: particle loss directly after the injection and development of instability in a deep cooled ion beam. Methods of the instability suppression, which allow increasing the cooled beam intensity, are described.

  2. Impurity beam-trapping instability in tokamaks

    International Nuclear Information System (INIS)

    Hogan, J.T.; Howe, H.C.

    1976-12-01

    The sensitivity of neutron energy production to the trapping by impurities by injected neutral beams is considered. The beam-trapping process is affected by inherent low-Z contamination of the tritium plasma, by the species composition of the neutral beam, and by the entrance angle of the beam. The sensitivities of the process are compared to these variables and to the variation with wall material. One finds that use of a low-Z, low sputtering material could retard a possible beam trapping instability

  3. 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.

  4. Experience with the new reverse injection scheme in the Tevatron

    International Nuclear Information System (INIS)

    Saritepe, S.; Goderre, G.; Annala, G.; Hanna, B.; Braun, A.

    1993-01-01

    In the new injection scenario the antiproton beam is injected onto a helical Tevatron orbit to avoid the detrimental effects of the beam-beam interaction at 150 GeV. The new scenario required changes in the tuning procedures. Antiprotons are too precious to be used for tuning, therefore the antiproton injection line has to be tuned with protons by reverse injecting them from the Tevatron into the Main Ring. Previously, the reverse injection was performed in one supercycle. One batch of uncoalesced bunches was injected into the Tevatron and ejected after 40 seconds. The orbit closure was performed in the Main Ring. In the new scheme the lambertson magnets have to be moved, separator polarities have to be switched, activities that cannot be completed in one supercycle. Therefore, the reverse injection sequence was changed. This involved the redefinition of TVBS (Tevatron Beam Synchronized Clock) event $D8 as MRBS (Main Ring Beam Synchronized Clock) $D8 thus making it possible to inject 6 proton batches (or coalesced bunches) and eject them one at a time on command, performing orbit closure each time in the Main Ring

  5. Status of the 160 MeV H- Injection into the CERN PSB

    CERN Document Server

    Weterings, W; Benedetto, E; Borburgh, J; Bracco, C; Carli, C; Goddard, B; Hanke, K; Mikulec, B; Newborough, A; Noulibos, R; Tan, J

    2012-01-01

    The 160 MeV H- beam from the LINAC4 will be injected into the 4 superimposed rings of the PS Booster (PSB) with a new H- charge-exchange injection system. This entails a massive upgrade of the injection region. The hardware requirements and constraints, the performance specifications and the design of the H- injection region are described.

  6. BEAM TRANSPORT LINES FOR THE BSNS.

    Energy Technology Data Exchange (ETDEWEB)

    WEI, J.

    2006-06-26

    This paper presents the design of two beam transport lines at the BSNS: one is the injection line from the Linac to the RCS and the other is the target line from the RCS to the target station. In the injection beam line, space charge effects, transverse halo collimation, momentum tail collimation and debunching are the main concerned topics. A new method of using triplet cells and stripping foils is used to collimate transverse halo. A long straight section is reserved for the future upgrading linac and debuncher. In the target beam line, large halo emittance, beam stability at the target due to kicker failures and beam jitters, shielding of back-scattering neutrons from the target are main concerned topics. Special bi-gap magnets will be used to reduce beam losses in the collimators in front of the target.

  7. Optical synchrotron radiation beam imaging with a digital mask

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hao [Univ. of Maryland, College Park, MD (United States); Fiorito, Ralph [Univ. of Maryland, College Park, MD (United States); Corbett, Jeff [SLAC National Accelerator Lab., Menlo Park, CA (United States); Shkvarunets, Anatoly [Univ. of Maryland, College Park, MD (United States); Tian, Kai [SLAC National Accelerator Lab., Menlo Park, CA (United States); Fisher, Alan [SLAC National Accelerator Lab., Menlo Park, CA (United States); Douglas, D. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Wilson, F. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Zhang, S. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Mok, W. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Mitsuhashi, T. [KEK, Tsukuba (Japan)

    2016-01-01

    The 3GeV SPEAR3 synchrotron light source operates in top-up injection mode with up to 500mA circulating in the storage ring (equivalently 392nC). Each injection pulse contains only 40-80 pC producing a contrast ratio between total stored charge and injected charge of about 6500:1. In order to study transient injected beam dynamics during User operations, it is desirable to optically image the injected pulse in the presence of the bright stored beam. In the present work this is done by re-imaging visible synchrotron radiation onto a digital micro-mirror-array device (DMD), which is then used as an optical mask to block out light from the bright central core of the stored beam. The physical masking, together with an asynchronously-gated, ICCD imaging camera makes it is possible to observe the weak injected beam component on a turn-by-turn basis. The DMD optical masking system works similar to a classical solar coronagraph but has some distinct practical advantages: i.e. rapid adaption to changes in the shape of the stored beam, high extinction ratio for unwanted light and minimum scattering from the primary beam into the secondary optics. In this paper we describe the DMD masking method, features of the high dynamic range point spread function for the SPEAR3 optical beam line and measurements of the injected beam in the presence of the stored beam.

  8. Upgrade of the LHC Injection Kicker Magnets

    OpenAIRE

    Barnes, M J; Adraktas, P; 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

    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 ...

  9. 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.

  10. EFFECT OF SPACE CHARGE ON STABILITY OF BEAM DISTRIBUTION IN THE SNS RING

    International Nuclear Information System (INIS)

    FEDOTOV, A.V.; WEI, J.; GLUCKSTERN, R.L.

    2001-01-01

    In the Spallation Neutron Source (SNS) ring, multi-turn injection is employed to obtain a large transverse beam size which significantly reduces the space-charge tune shift of the accumulated beam. Careful choice of the painting scheme and bump function is required to obtain the desired beam profile together with low beam loss. In this paper we examine, both analytically and numerically, the effect of the space charge on the beam profile during multi-turn injection painting

  11. Safe injection procedures, injection practices, and needlestick ...

    African Journals Online (AJOL)

    Safe injection procedures, injection practices, and needlestick injuries among health care workers in operating rooms. Nermine Mohamed Tawfik Foda, Noha Selim Mohamed Elshaer, Yasmine Hussein Mohamed Sultan ...

  12. 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.

  13. Safe injection procedures, injection practices, and needlestick ...

    African Journals Online (AJOL)

    Nermine Mohamed Tawfik Foda

    2017-01-10

    Jan 10, 2017 ... tionnaire was administered to HCWs (n = 318) at the Alexandria Main University Hospital. Results: Safe injection procedures regarding final waste disposal were sufficiently adopted, while mea- sures regarding disposable injection equipment, waste containers, hand hygiene, as well as injection practices ...

  14. Elliptical beams.

    Science.gov (United States)

    Bandres, Miguel A; Gutiérrez-Vega, Julio C

    2008-12-08

    A very general beam solution of the paraxial wave equation in elliptic cylindrical coordinates is presented. We call such a field an elliptic beam (EB). The complex amplitude of the EB is described by either the generalized Ince functions or the Whittaker-Hill functions and is characterized by four parameters that are complex in the most general situation. The propagation through complex ABCD optical systems and the conditions for square integrability are studied in detail. Special cases of the EB are the standard, elegant, and generalized Ince-Gauss beams, Mathieu-Gauss beams, among others.

  15. 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 treat ... in the treatment of certain serious infections. Penicillin G procaine injection is in a class of medications ...

  16. 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...

  17. Online measurement of electron beam parameters by image processing

    International Nuclear Information System (INIS)

    Tyagi, Y.; Puntambekar, T.A.

    2010-01-01

    The basic image acquisition software which was developed earlier has been recently upgraded to support online measurement of beam centroid, beam height and beam width from the diagnostic devices namely fluorescent screen beam profile monitors and beam slit monitor installed in Transport Line -1(TL-1) at Indus Accelerator Complex at RRCAT, Indore. The online measurement of these electron beam parameters has helped the Indus operation team to take necessary corrective action if required before injection of the electron beam into booster synchrotron. This paper presents the methodology adopted for online measurement of above parameters in the software. (author)

  18. Experimental results from a diagnostic beam line for text

    International Nuclear Information System (INIS)

    Coupland, J.R.; Hammond, D.P.; Mepham, J.W.; Hancock, O.J.

    1987-01-01

    The experimental performance of a high brightness neutral beam system is described. The neutral beam serves as a diagnostic on the Fusion Research Center Tokamak TEXT, to measure impurities by observing optical spectra produced by collisions between the injected neutral beam and ions in the plasma

  19. Beam experiment at TARN

    International Nuclear Information System (INIS)

    Noda, A.; Chida, K.; Hattori, T.

    1984-01-01

    TARN is a storage ring of low energy ions (T sub(N) -- 10 MeV/u) constructed in 1979 to verify the feasibility of intensity multiplication proposed at NUMATRON project. The mean radius and maximum magnetic rigidity of the ring are 5.06 m and 11.8 kG.m, respectively. Magnet system based on a strong focusing FODO lattice is composed of 8 dipole and 16 quadrupole magnets. Additional 12 sextupole magnets are also installed for chromaticity control. Intensity increase by the multi-turn injection is 20 times with the dilution factor of 2.0 in horizontal transverse phase space. Injected beams are RF captured with the frequency around 8 MHz and moved inner side of the ring by RF deceleration as large as -- 5 % in Δp/p. Beam intensity increases linearly up to around 20 stackings with the capture efficiency of 80 % and 30 Hz repetition rate. Dilution factor of the longitudinal phase space is measured at 1.8. Thus about 300 times total intensity increase has been attained. The e-folding beam life time of 7 MeV proton is measured at 400 s for the vacuum pressure of 1 x 10 -10 Torr. Stochastic momentum cooling experiment of 7 MeV proton has been performed. A feed-back system based on the 'Notch-Filter' method has been adopted for its simplicity and characteristics suitable for lower beam intensity. Cooling time for the 7 MeV proton beam with the intensity of 10 8 is estimated at 19 s for optimum cooling rate with the system gain of 105 dB, while the system gain as large as 111 dB has been achieved without self-oscillation of the electronics system. From the beam experiment, the cooling time of 10 8 proton beam with fractional momentum spread of 1.4 x 10 -2 is measured at --20 sec with the system gain of 97 db. (author)

  20. Superresolution beams

    CSIR Research Space (South Africa)

    Ngcobo, S

    2012-07-01

    Full Text Available positions of p zeros of intensity distributions on the Gaussian beam, resulting to a generation of TEMp0 beams where there are minimum losses. The LGBs are well-known family of exact orthogonal solutions of free-space paraxial wave equation in cylindrical...

  1. Beam diagnostics

    CERN Document Server

    Raich, U

    2008-01-01

    Most beam measurements are based on the electro-magnetic interaction of fields induced by the beam with their environment. Beam current transformers as well as beam position monitors are based on this principle. The signals induced in the sensors must be amplified and shaped before they are converted into numerical values. These values are further treated numerically in order to extract meaningful machine parameter measurements. The lecture introduces the architecture of an instrument and shows where in the treatment chain digital signal analysis can be introduced. Then the use of digital signal processing is presented using tune measurements, orbit and trajectory measurements as well as beam loss detection and longitudinal phase space tomography as examples. The hardware as well as the treatment algorithms and their implementation on Digital Signal Processors (DSPs) or in Field Programmable Gate Arrays (FPGAs) are presented.

  2. Alternative Designs for the NSLS-II Injection Straight Section

    Energy Technology Data Exchange (ETDEWEB)

    Shaftan,T.; Heese, R.; Weihreter, E.; Willeke, F.; Rehak, M.; Meier, R.; Fliller, R.; Johnson, E. D.

    2009-05-04

    Brookhaven National Laboratory (BNL) is developing a state-of-the-art 3 GeV synchrotron light source, the NSLS-II [1]. The 9.3 meter-long injection straight section of its storage ring now fits a conventional injection set-up consisting of four kickers producing a closed bump, together with a DC septum and a pulsed septum. In this paper, we analyze an alternative option based on injection via a pulsed sextupole magnet. We discuss the dynamics of the injected and stored beams and, subsequently, the magnet's specifications and tolerances. We conclude by summarized the advantages and drawbacks of each injection scheme.

  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. Numerical simulation of injection and resistive trapping of ion rings

    International Nuclear Information System (INIS)

    Mankofsky, A.; Friedman, A.; Sudan, R.N.

    1981-01-01

    Numerical studies of the injection and resistive trapping efficiency of ion rings, using an improved algorithm are presented. Trapping efficiency is found to be strongly dependent upon the number of particles injected and upon mirror ratios in the system. Wall resistivity and beam divergence affect the process to a lesser extent. (author)

  5. Layout considerations for the PSB H- injection system

    CERN Document Server

    Aiba, M; Carli, C; Chanel, M; Fowler, A; Goddard, B; Weterings, W

    2009-01-01

    The layout of the PSB H- injection system is described, including the arguments for the geometry and the required equipment performance parameters. The longitudinal positions of the main elements are specified, together with the injected and circulating beam axes. The assumptions used in determining the geometry are listed.

  6. 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...

  7. Intense relativistic electron beam: generation and propagation

    International Nuclear Information System (INIS)

    Mittal, K.C.; Mondal, J.

    2010-01-01

    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 V 3/2 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)

  8. Feasibility study of beam-beam compensation in the Tevatron with wires

    International Nuclear Information System (INIS)

    Sen, Tanaji; Erdelyi, Bela

    2005-01-01

    We explore the possibility of compensating long-range beam-beam interactions in the Tevatron by current carrying wires. Compensation strategies depend on whether the compensation is done close to the interaction or nonlocally, on the aspect ratio of the strong beam and on other details. Strategies for each case have been developed and applied to the Tevatron. We discuss the results of these strategies at injection and collision energy

  9. AA, beam stopper with scintillator screen

    CERN Multimedia

    CERN PhotoLab

    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.

  10. Phase measurement and control of bunched beams

    International Nuclear Information System (INIS)

    Lewis, R.N.

    1978-01-01

    An ion bean buncher was developed at ANL for bunching all ion species through a tandem accelerator. Transit time variations through the tandem, caused by ripple and fluctuations in the injection and lens power supplies and terminal voltage, and to varying voltage distributions in the accelerating tube, cause a beam-phase variation at the output of the tandem. A beam-phase measurement and control system was designed and installed in conjunction with the ion beam buncher to control beam phase at the tandem output. That system is described

  11. Manipulation and electron-oscillation-measurement of laser accelerated electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Kotaki, H; Hayashi, Y; Kawase, K; Mori, M; Kando, M; Homma, T; Koga, J K; Daido, H; Bulanov, S V, E-mail: kotaki.hideyuki@jaea.go.jp [Advanced Photon Research Center, Japan Atomic Energy Agency, 8-1-7, Umemidai, Kizugawa, Kyoto (Japan)

    2011-01-15

    Monoenergetic electron beams have been generated in the self-injection scheme of laser acceleration. In applications of these laser accelerated electron beams, stable and controllable electron beams are necessary. A stable electron beam is generated in the self-injection scheme by using a nitrogen gas jet target. We found the profile of the electron beam was manipulated by rotating the laser polarization. The electron beam is in the first bucket of the wake wave. In the energy space, transverse oscillation is observed when the laser pulse has S-polarization. The direction of the electron beam is controlled by the gas jet position.

  12. 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.

  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. Molecular beams

    International Nuclear Information System (INIS)

    Ramsey, N.F.

    1985-01-01

    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

  15. Beam transport

    International Nuclear Information System (INIS)

    1988-01-01

    Considerable experience has now been gained with the various beam transport lines, and a number of minor changes have been made to improve the ease of operation. These include: replacement of certain little-used slits by profile monitors (harps or scanners); relocation of steering magnets, closer to diagnostic harps or profile scanners; installation of a scanner inside the isocentric neutron therapy system; and conversion of a 2-doublet quadrupole telescope (on the neutron therapy beamline) to a 2-triplet telescope. The beam-swinger project has been delayed by very late delivery of the magnet iron to the manufacturer, but is now progressing smoothly. The K=600 spectrometer magnets have now been delivered and are being assembled for field mapping. The x,y-table with its associated mapping equipment is complete, together with the driver software. One of the experimental areas has been dedicated to the production of collimated neutron beams and has been equipped with a bending magnet and beam dump, together with steel collimators fixed at 4 degrees intervals from 0 degrees to 16 degrees. Changes to the target cooling and shielding system for isotope production have led to a request for much smaller beam spot sizes on target, and preparations have been made for rearrangement of the isotope beamline to permit installation of quadrupole triplets on the three beamlines after the switching magnet. A practical system of quadrupoles for matching beam properties to the spectrometer has been designed. 6 figs

  16. PEP-II injection timing and controls

    International Nuclear Information System (INIS)

    Bharadwaj, V.; Browne, M.; Crane, M.; Gromme, T.; Himel, T.; Ross, M.; Stanek, M.; Ronan, M.

    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

  17. AA injection kicker in its tank

    CERN Multimedia

    CERN PhotoLab

    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.

  18. Septa and Distributor Developments for H- Injection into the Booster from LINAC4

    CERN Document Server

    Borburgh, J; Fowler, T; Hourican, M; Weterings, W

    2008-01-01

    The construction of Linac4 requires the modification of the existing injection system of the CERN PS Booster. A new transfer line will transport 160 MeV H- ions to this machine. A system of 5 pulsed magnets (BIDIS) and 3 vertical septa (BISMV) will distribute and inject the Linac pulses into the four-vertically separated Booster rings. Subsequently the beam will be injected horizontally, using a local bump created with bumpers (BS magnets) to bring the injected H- beam together with the orbiting proton beam onto the stripper foil. To accommodate the injected H- beam, the first of the BS magnets will have to be a septum-like device, deflecting only the orbiting beam. This paper highlights the requirements and technical issues and describes the solutions to be adopted for both the BIDIS and BISMV. The results of initial prototype testing of the BIDIS magnet will also be presented.

  19. A Study of the Effect of Beam-Beam Interactions on CESR Optics

    CERN Document Server

    Crittenden, James Arthur; Rubin, David

    2005-01-01

    The CESR storage ring facility has begun operation in an energy region which allows high-statistics investigation of charm-quark bound states. Experience during the first year has shown that the effects of parasitic crossings in the pretzel orbits present an important factor in injection efficiency, in the beam lifetime and stored current limits. We compare the results of beam dynamics and tracking calculations which quantify the effects of these parasitic crossings on optics and dynamic aperture for the injected and stored trajectories to observations of beam behavior.

  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. Beam Loss Simulation Studies for ALS Top-Off Operation

    CERN Document Server

    Nishimura, Hiroshi; Robin, David; Steier, Christoph

    2005-01-01

    The ALS is planning to operate with top-off injection at higher beam currents and smaller vertical beam size. As part of a radiation safety study for top-off, we carried out two kinds of tracking studies: (1) to confirm that the injected beam cannot go into users' photon beam lines, and (2) to control the location of beam dump when the storage ring RF is tripped. (1) is done by tracking electrons from a photon beam line to the injection sector inversely by including the magnetic field profiles, varying the field strength with geometric aperture limits to conclude that it is impossible. (2) is done by tracking an electron with radiation in the 6-dim space for different combinations of vertical scrapers for the realistic lattice with errors.

  2. Measurements of beam-ion confinement during tangential beam-driven instabilities in PBX [Princeton Beta Experiment

    International Nuclear Information System (INIS)

    Heidbrink, W.W.; Kaita, R.; Takahashi, H.; Gammel, G.; Hammett, G.W.; Kaye, S.

    1987-01-01

    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

  3. Plasma diagnostic techniques using particle beam probes

    International Nuclear Information System (INIS)

    Jennings, W.C.

    1980-07-01

    A brief overview is given of particle beam probing. The fundamental concepts common to all techniques are discussed as well as the design considerations for choosing a particular diagnostic technique. The capabilities of existing and proposed techniques, and the present status of the techniques in major magnetic confinement geometries is also presented. Techniques which involve the injection of a beam of neutral particles into the plasma are then considered. The techniques of beam attenuation, beam scattering, and active charge exchange using a beam of light particles such as hydrogen or helium are first presented. Optical measurements of the Zeeman splitting of the radiation from a neutral lithium beam is then discussed, including a new proposal for significantly improving this technique through the addition of a dye laser. Two techniques involving the injection of heavy neutral particles are then presented, and the section concludes with two proposed techniques for measuring the properties of the alpha particles produced from actual fusion reactions. The diagnostic techniques which are based upon the injection of a beam of charged particles into the plasma are next described. The advantages and limitations of these techniques in comparison with the neutral techniques are discussed, followed by a description of specific techniques

  4. Plasma diagnostic techniques using particle beam probes

    Energy Technology Data Exchange (ETDEWEB)

    Jennings, W C

    1980-07-01

    A brief overview is given of particle beam probing. The fundamental concepts common to all techniques are discussed as well as the design considerations for choosing a particular diagnostic technique. The capabilities of existing and proposed techniques, and the present status of the techniques in major magnetic confinement geometries is also presented. Techniques which involve the injection of a beam of neutral particles into the plasma are then considered. The techniques of beam attenuation, beam scattering, and active charge exchange using a beam of light particles such as hydrogen or helium are first presented. Optical measurements of the Zeeman splitting of the radiation from a neutral lithium beam is then discussed, including a new proposal for significantly improving this technique through the addition of a dye laser. Two techniques involving the injection of heavy neutral particles are then presented, and the section concludes with two proposed techniques for measuring the properties of the alpha particles produced from actual fusion reactions. The diagnostic techniques which are based upon the injection of a beam of charged particles into the plasma are next described. The advantages and limitations of these techniques in comparison with the neutral techniques are discussed, followed by a description of specific techniques.

  5. Effect of the helium injection mode on swelling of austenitic steels

    International Nuclear Information System (INIS)

    Gilbon, Didier; Rivera, Christian; Levy, Viviane

    1984-01-01

    The effect of helium and its injection mode on the microstructure of 316 and Ti-modified 316 steels, both in their solution annealed and cold worked states is studied. Irradiations have been conducted in a dual beam accelerator to doses above 100 dpa and different injection modes have been investigated: cold preinjection, hot preinjection, and dual beam. The results show that the effect of helium is largely dependent on its injection mode, but also on chemical composition of the alloy considered. (author)

  6. Quantum beams

    International Nuclear Information System (INIS)

    Uesaka, Mitsuru

    2003-01-01

    Present state and future prospect are described on quantum beams for medical use. Efforts for compactness of linac for advanced cancer therapy have brought about the production of machines like Accuray's CyberKnife and TOMOTHERAPY (Tomo Therapy Inc.) where the acceleration frequency of X-band (9-11 GHz) is used. For cervical vein angiography by the X-band linac, a compact hard X-ray source is developed which is based on the (reverse) Compton scattering through laser-electron collision. More intense beam and laser are necessary at present. A compact machine generating the particle beam of 10 MeV-1 GeV (laser-plasma accelerator) for cancer therapy is also developed using the recent compression technique (chirped-pulse amplification) to generate laser of >10 TW. Tokyo University is studying for the electron beam with energy of GeV order, for the laser-based synchrotron X-ray, and for imaging by the short pulse ion beam. Development of advanced compact accelerators is globally attempted. In Japan, a virtual laboratory by National Institute of Radiological Sciences (NIRS), a working group of universities and research facilities through the Ministry of Education, Culture, Sports, Science and Technology, started in 2001 for practical manufacturing of the above-mentioned machines for cancer therapy and for angiography. Virtual Factory (Inc.), a business venture, is to be stood in future. (N.I.)

  7. 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 ...

  8. Aminocaproic Acid Injection

    Science.gov (United States)

    Aminocaproic acid injection is used to control bleeding that occurs when blood clots are broken down too quickly. This ... the baby is ready to be born). Aminocaproic acid injection is also used to control bleeding in ...

  9. Deoxycholic Acid Injection

    Science.gov (United States)

    Deoxycholic acid injection is used to improve the appearance and profile of moderate to severe submental fat ('double chin'; fatty tissue located under the chin). Deoxycholic acid injection is in a class of medications called ...

  10. Corticotropin, Repository Injection

    Science.gov (United States)

    ... injection is used to treat the following conditions:infantile spasms (seizures that usually begin during the first year ... tell how corticotropin repository injection works to treat infantile spasms.

  11. Advanced Light Source beam position monitor

    International Nuclear Information System (INIS)

    Hinkson, J.

    1991-01-01

    The Advanced Light Source (ALS) is a synchrotron radiation facility nearing completion at LBL. As a third-generation machine, the ALS is designed to produce intense light from bend magnets, wigglers, and undulators (insertion devices). The facility will include a 50 MeV electron linear accelerator, a 1.5 GeV booster synchrotron, beam transport lines, a 1--2 GeV storage ring, insertion devices, and photon beam lines. Currently, the beam injection systems are being commissioned, and the storage ring is being installed. Electron beam position monitors (BPM) are installed throughout the accelerator and constitute the major part of accelerator beam diagnostics. The design of the BPM instruments is complete, and 50 units have been constructed for use in the injector systems. We are currently fabricating 100 additional instruments for the storage ring. In this paper I discuss engineering fabrication, testing and performance of the beam pickup electrodes and the BPM electronics

  12. Neutral-beam-heating applications and development

    International Nuclear Information System (INIS)

    Menon, M.M.

    1981-01-01

    The technique of heating the plasma in magnetically confined fusion devices by the injection of intense beams of neutral atoms is described. The basic principles governing the physics of neutral beam heating and considerations involved in determining the injection energy, power, and pulse length required for a fusion reactor are discussed. The pertinent experimental results from various fusion devices are surveyed to illustrate the efficacy of this technique. The second part of the paper is devoted to the technology of producing the neutral beams. A state-of-the-art account o the development of neutral injectors is presented, and the prospects for utilizing neutral injection to heat the plasma in a fusion reactor are examined

  13. Beam Diagnostics of the Small Isochronous Ring

    Energy Technology Data Exchange (ETDEWEB)

    Felix Marti; Eduard Pozdeyev

    2004-07-01

    The purpose of this paper is to describe the beam diagnostic systems in the Small Isochronous Ring (SIR) developed and built at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University (MSU). SIR is a small-scale experiment that simulates the dynamics of intense beams in large accelerators. A 20 to 30 keV hydrogen or deuterium ion bunch is injected in the ring, extracted after a variable number of turns and its longitudinal profile is studied. Some of the diagnostic tools available in SIR include an emittance measurement system in the injection line, scanning wires in different sections of the ring, phosphor screens at the injection and extraction points and a fast Faraday cup in the extraction line. The design of these systems and the kind of beam information they provide are discussed in detail.

  14. Geothermal injection monitoring project

    Energy Technology Data Exchange (ETDEWEB)

    Younker, L.

    1981-04-01

    Background information is provided on the geothermal brine injection problem and each of the project tasks is outlined in detail. These tasks are: evaluation of methods of monitoring the movement of injected fluid, preparation for an eventual field experiment, and a review of groundwater regulations and injection programs. (MHR)

  15. Injection moulding antireflective nanostructures

    DEFF Research Database (Denmark)

    Christiansen, Alexander Bruun; Clausen, Jeppe Sandvik; Mortensen, N. Asger

    2014-01-01

    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...

  16. Injection moulding antireflective nanostructures

    DEFF Research Database (Denmark)

    Christiansen, Alexander Bruun; Clausen, Jeppe Sandvik; Mortensen, N. Asger

    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...

  17. BEAM-BEAM SIMULATIONS FOR DOUBLE-GAUSSIAN BEAMS.

    Energy Technology Data Exchange (ETDEWEB)

    MONTAG, C.; MALITSKY, N.; BEN-ZVI, I.; LITVINENKO, V.

    2005-05-16

    Electron cooling together with intra-beam scattering results in a transverse distribution that can best be described by a sum of two gaussians, one for the high-density core and one for the tails of the distribution. Simulation studies are being performed to understand the beam-beam interaction of these double-gaussian beams. Here we report the effect of low-frequency random tune modulations on diffusion in double-gaussian beams and compare the effects to those in beam-beam interactions with regular gaussian beams and identical tune shift parameters.

  18. BEAM-BEAM SIMULATIONS FOR DOUBLE-GAUSSIAN BEAMS

    International Nuclear Information System (INIS)

    MONTAG, C.; MALITSKY, N.; BEN-ZVI, I.; LITVINENKO, V.

    2005-01-01

    Electron cooling together with intra-beam scattering results in a transverse distribution that can best be described by a sum of two gaussians, one for the high-density core and one for the tails of the distribution. Simulation studies are being performed to understand the beam-beam interaction of these double-gaussian beams. Here we report the effect of loW--frequency random tune modulations on diffusion in double-gaussian beams and compare the effects to those in beam-beam interactions with regular gaussian beams and identical tune shift parameters

  19. Beam-Beam Simulations for Double-Gaussian Beams

    CERN Document Server

    Montag, Christoph; Litvinenko, Vladimir N; Malitsky, Nikolay

    2005-01-01

    Electron cooling together with intra-beam scattering results in a transverse distribution that can best be described by a sum of two Gaussians, one for the high-density core and one for the tails of the distribution. Simulation studies are being performed to understand the beam-beam interaction of these double-Gaussian beams. Here we report the effect of low-frequency random tune modulations on diffusion in double-Gaussian beams and compare the effects to those in beam-beam interactions with regular Gaussian beams and identical tuneshift parameters.

  20. TRANSIENT BEAM LOADING EFFECTS IN RF SYSTEMS IN JLEIC

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Haipeng [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Guo, Jiquan [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Rimmer, Robert A. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Wang, Shaoheng [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-05-01

    The pulsed electron bunch trains generated from the Continuous Electron Beam Accelerator Facility (CEBAF) linac to inject into the proposed Jefferson Lab Electron Ion Collider (JLEIC) e-ring will produce transient beam loading effects in the Superconducting Radio Frequency (SRF) systems that, if not mitigated, could cause unacceptably large beam energy deviation in the injection capture, or exceed the energy acceptance of CEBAF’s recirculating arcs. In the electron storage ring, the beam abort or ion clearing gaps or uneven bucket filling can cause large beam phase transients in the (S)RF cavity control systems and even beam loss due to Robinson instability. We have first analysed the beam stability criteria in steady state and estimated the transient effect in Feedforward and Feedback RF controls. Initial analytical models for these effects are shown for the design of the JLEIC e-ring from 3GeV to 12GeV.

  1. Neutralization principles for the Extraction and Transport of Ion Beams

    CERN Document Server

    Riege, H

    2000-01-01

    The strict application of conventional extraction techniques of ion beams from a plasma source is characterized by a natural intensity limit determined by space charge.The extracted current may be enhanced far beyond this limit by neutralizing the space charge of the extracted ions in the first extraction gap of the source with electrons injected from the opposite side. The transverse and longitudinal emittances of a neutralized ion beam, hence its brightness, are preserved. Results of beam compensation experiments, which have been carried out with a laser ion source, are resumed for proposing a general scheme of neutralizing ion sources and their adjacent low-energy beam transport channels with electron beams. Many technical applications of high-mass ion beam neutralization technology may be identified: the enhancement of ion source output for injection into high-intensity, low-and high-energy accelerators, or ion thrusters in space technology, for the neutral beams needed for plasma heating of magnetic conf...

  2. ISX-B neutral beams and the beam target experiment

    Energy Technology Data Exchange (ETDEWEB)

    Bates, S.C.; Edmonds, P.H.; Kim, J.; Bush, C.E.; Massengill, L.A.; Overbey, D.R.; Pearce, J.W.

    1980-10-01

    This report describes the hardware and operation of the ISX neutral beamlines as well as an experiment done to verify estimates of the neutral power injected into the tokamak. Tangential coinjection of megawatt levels of 30 to 40-keV neutrals into the tokamak has made the study of high-beta plasmas in ISX possible. These power levels were achieved with high reliability (over 90%) by two neutral beamlines with design power ratings of 900 kW of H/sup 0/ (upgraded to 1.5 MW) each. The neutral beamlines consist of a duoPIGatron plasma generator, acceleration grids, a gas neutralization cell, an ion deflection magnet, beam calorimetry, high-speed helium cryocondensation vacuum pumps, and associated electrical and control systems. The beamlines and their operation are described briefly with an emphasis on their relation to injection into a plasma. Neutral injection geometry with respect to the tokamak is given.

  3. 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 ...

  4. PDX neutral-beam reionization losses

    International Nuclear Information System (INIS)

    Kugel, H.W.; Dylla, H.F.; Eubank, H.P.; Kozub, T.A.; Moore, R.; Schilling, G.; Stewart, L.D.; von Halle, A.; Williams, M.D.

    1982-02-01

    Reionization losses for 1.5 MW H 0 and 2 MW D 0 neutral beams injected into the PDX tokamak were studied using pressure gauges, photo-transistors, thermocouples, surface shielding, and surface sample analysis. Considerable outgassing of conventionally prepared 304SS ducts occurred during initial injections and gradually decreased with the cumulative absorption of beam power. Reionization power losses are presently about 5% in the ducts and about 12% total for a beamline including the duct. Present duct pressures are attributed primarily to gas from the ion source and neutralizer with much smaller contributions from residual wall desorption. Physical mechanisms for the observed duct outgassing are discussed

  5. Doppler-shifted neutral beam line shape and beam transmission

    Energy Technology Data Exchange (ETDEWEB)

    Kamperschroer, J.H.; Grisham, L.R.; Kokatnur, N.; Lagin, L.J.; Newman, R.A.; O`Connor, T.E.; Stevenson, T.N.; von Halle, A.

    1994-04-01

    Analysis of Doppler-shifted Balmer-{alpha} line emission from the TFTR neutral beam injection systems has revealed that the line shape is well approximated by the sum of two Gaussians, or, alternatively, by a Lorentzian. For the sum of two Gaussians, the broad portion of the distribution contains 40% of the beam power and has a divergence five times that of the narrow part. Assuming a narrow 1/e- divergence of 1.3{degrees} (based on fits to the beam shape on the calorimeter), the broad part has a divergence of 6.9{degrees}. The entire line shape is also well approximated by a Lorentzian with a half-maximum divergence of 0.9{degrees}. Up to now, fusion neutral beam modelers have assumed a single Gaussian velocity distribution, at the extraction plane, in each direction perpendicular to beam propagation. This predicts a beam transmission efficiency from the ion source to the calorimeter of 97%. Waterflow calorimetry data, however, yield a transmission efficiency of {approximately}75%, a value in rough agreement with predictions of the Gaussian or Lorentzian models presented here. The broad wing of the two Gaussian distribution also accurately predicts the loss in the neutralizer. An average angle of incidence for beam loss at the exit of the neutralizer is 2.2{degrees}, rather than the 4.95{degrees} subtended by the center of the ion source. This average angle of incidence, which is used in computing power densities on collimators, is shown to be a function of beam divergence.

  6. Doppler-shifted neutral beam line shape and beam transmission

    International Nuclear Information System (INIS)

    Kamperschroer, J.H.; Grisham, L.R.; Kokatnur, N.; Lagin, L.J.; Newman, R.A.; O'Connor, T.E.; Stevenson, T.N.; von Halle, A.

    1994-04-01

    Analysis of Doppler-shifted Balmer-α line emission from the TFTR neutral beam injection systems has revealed that the line shape is well approximated by the sum of two Gaussians, or, alternatively, by a Lorentzian. For the sum of two Gaussians, the broad portion of the distribution contains 40% of the beam power and has a divergence five times that of the narrow part. Assuming a narrow 1/e- divergence of 1.3 degrees (based on fits to the beam shape on the calorimeter), the broad part has a divergence of 6.9 degrees. The entire line shape is also well approximated by a Lorentzian with a half-maximum divergence of 0.9 degrees. Up to now, fusion neutral beam modelers have assumed a single Gaussian velocity distribution, at the extraction plane, in each direction perpendicular to beam propagation. This predicts a beam transmission efficiency from the ion source to the calorimeter of 97%. Waterflow calorimetry data, however, yield a transmission efficiency of ∼75%, a value in rough agreement with predictions of the Gaussian or Lorentzian models presented here. The broad wing of the two Gaussian distribution also accurately predicts the loss in the neutralizer. An average angle of incidence for beam loss at the exit of the neutralizer is 2.2 degrees, rather than the 4.95 degrees subtended by the center of the ion source. This average angle of incidence, which is used in computing power densities on collimators, is shown to be a function of beam divergence

  7. Cooled Beam Diagnostics on LEIR

    CERN Document Server

    Tranquille, G; Carli, C; Chanel, M; Prieto, V; Sautier, R; Tan, J

    2008-01-01

    Electron cooling is central in the preparation of dense bunches of lead beams for the LHC. Ion beam pulses from the LINAC3 are transformed into short highbrightness bunches using multi-turn injection, cooling and accumulation in the Low Energy Ion Ring, LEIR [1]. The cooling process must therefore be continuously monitored in order to guarantee that the lead ions have the required characteristics in terms of beam size and momentum spread. In LEIR a number of systems have been developed to perform these measurements. These include Schottky diagnostics, ionisation profile monitors and scrapers. Along with their associated acquisition and analysis software packages these instruments have proved to be invaluable for the optimisation of the electron cooler.

  8. Method for Converter Synchronization with RF Injection

    OpenAIRE

    Joshua P. Bruckmeyer; Ivica Kostanic

    2015-01-01

    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 simu...

  9. PLT neutral injection ignitron accelerating supply

    International Nuclear Information System (INIS)

    Ashcroft, D.L.; Murray, J.G.; Newman, R.A.; Peterson, F.L.

    1976-03-01

    A phase-controlled rectifier has been designed for the accelerating supply on the PLT Neutral Beam Injection system at PPPL. The rectifier must furnish 70 amperes at up to 50 KV for 300 milliseconds, with a duty cycle of up to 10 percent. Protection of the injectors requires the supply to withstand repeated crowbarring. The rectifying element selected to satisfy these requirements was a commercially-available ignitron, installed in a supporting frame and using firing circuits and controls designed by PPPL

  10. Theory of suppression of loss cone instabilities by electron beams

    International Nuclear Information System (INIS)

    Sinha, A.; Sinha, M.

    1981-01-01

    A new mechanism for the suppression of Drift Cyclotron Loss Cone instabilities by electron beams injected along the field lines is given. The mechanism explains some of the recent observations. (author)

  11. Feedback correction of injection errors using digital signal-processing techniques

    Directory of Open Access Journals (Sweden)

    N. S. Sereno

    2007-01-01

    Full Text Available Efficient transfer of electron beams from one accelerator to another is important for 3rd-generation light sources that operate using top-up. In top-up mode, a constant amount of charge is injected at regular intervals into the storage ring to replenish beam lost primarily due to Touschek scattering. Top-up therefore requires that the complex of injector accelerators that fill the storage ring transport beam with a minimum amount of loss. Injection can be a source of significant beam loss if not carefully controlled. In this note we describe a method of processing injection transient signals produced by beam-position monitors and using the processed data in feedback. Feedback control using the technique described here has been incorporated in the Advanced Photon Source (APS booster synchrotron to correct injection transients.

  12. Improved performance of laser wakefield acceleration by tailored self-truncated ionization injection

    Science.gov (United States)

    Irman, A.; Couperus, J. P.; Debus, A.; Köhler, A.; Krämer, J. M.; Pausch, R.; Zarini, O.; Schramm, U.

    2018-04-01

    We report on tailoring ionization-induced injection in laser wakefield acceleration so that the electron injection process is self-truncating following the evolution of the plasma bubble. Robust generation of high-quality electron beams with shot-to-shot fluctuations of the beam parameters better than 10% is presented in detail. As a novelty, the scheme was found to enable well-controlled yet simple tuning of the injected charge while preserving acceleration conditions and beam quality. Quasi-monoenergetic electron beams at several 100 MeV energy and 15% relative energy spread were routinely demonstrated with a total charge of the monoenergetic feature reaching 0.5 nC. Finally these unique beam parameters, suggesting unprecedented peak currents of several 10 kA, are systematically related to published data on alternative injection schemes.

  13. Beam lifetime measurement and analysis in Indus-2 electron ...

    Indian Academy of Sciences (India)

    injection septum, four injection kickers, four RF cavities and five insertion devices. Indus-2 synchrotron radiation facility consists of a pre-injector (microtron, which deliv- ers 20 MeV electron beam of 0.5 μs pulse width), an injector (booster synchrotron, which raises beam energy from 20 MeV to 550 MeV) and the storage ring ...

  14. Energetic ion diagnostics using neutron flux measurements during pellet injection

    Energy Technology Data Exchange (ETDEWEB)

    Heidbrink, W.W.

    1986-01-01

    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.

  15. Trapping of gun-injected plasma by a tokamak

    International Nuclear Information System (INIS)

    Leonard, A.W.; Dexter, R.N.; Sprott, J.C.

    1986-10-01

    It is shown that a plasma produced by a Marshall gun can be injected into and trapped by a tokamak plasma. Gun injection raises the line-averaged density and peaks the density profile. Trapping of the gun-injected plasma is explainable in terms of a depolarization current mechanism. A model is developed which describes the slowing of a plasma beam crossing into the magnetic field of a tokamak. The slowing down time is shown to go as tau/sub s/ ∞ n -1 /sub b/T 3 /sub e/(α 0 /L) 2 , where n/sub b/ and T/sub e/ are the density and temperature of the plasma beam and α 0 /L is the pitch of the field lines per unit length in the direction in which the beam is traveling. Experimental tests of this model are consistent with the scaling predictions

  16. Energetic ion diagnostics using neutron flux measurements during pellet injection

    International Nuclear Information System (INIS)

    Heidbrink, W.W.

    1986-01-01

    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

  17. 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 ...

  18. Impurity beam-trapping instability in tokamaks

    International Nuclear Information System (INIS)

    Hogan, J.T.; Howe, H.C.

    1976-01-01

    The sensitivity of neutron energy production to the impurity trapping of injected neutral beams is considered. This process is affected by inherent low-Z contamination of the tritium pre-heat plasma, by the species composition of the neutral beam, and by the entrance angle of the beam. The sensitivities of the process to these variables, and to the variation of wall material are compared. One finds that successful use of a low-Z, low-sputtering material can appreciably lengthen the useful pulse length

  19. Properties of the TRIUMF cyclotron beam

    International Nuclear Information System (INIS)

    Craddock, M.K.; Blackmore, E.W.; Dutto, G.; Kost, C.J.; Mackenzie, G.H.; Richardson, J.R.; Root, L.W.; Schmor, P.

    1975-08-01

    Eight percent of the 300 keV d.c. beam from the ion source can be transmitted to 500 MeV in the TRIUMF cyclotron, without using the buncher. The beam losses are entirely accounted for; there are no significant losses due to orbit dynamic problems during 1500 turns of acceleration. The phase history is in good agreement with predictions based on the magnetic field survey. The effect of the harmonic coils and injection parameters on beam quality has been investigated. (author)

  20. Beam transport

    International Nuclear Information System (INIS)

    1988-01-01

    The beam diagnostic components for both the transfer and the high-energy beamlines perform well except for some of the scanners whose noise pick-up has become a problem, especially at low beam intensities. This noise pick-up is primarily due to deterioration of the bearings in the scanner. At some locations in the high-energy beamlines, scanners were replaced by harps as the scanners proved to be practically useless for the low-intensity beams required in the experimental areas. The slits in the low-energy beamline, which are not water-cooled, have to be repaired at regular intervals because of vacuum leaks. Overheating causes the ceramic feedthroughs to deteriorate resulting in the vacuum leaks. Water-cooled slits have been ordered to replace the existing slits which will later be used in the beamlines associated with the second injector cyclotron SPC2. The current-measurement system will be slightly modified and should then be much more reliable. 3 figs

  1. 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 inject......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...

  2. SQL injection detection system

    OpenAIRE

    Vargonas, Vytautas

    2017-01-01

    SQL injection detection system Programmers do not always ensure security of developed systems. That is why it is important to look for solutions outside being reliant on developers. In this work SQL injection detection system is proposed. The system analyzes HTTP request parameters and detects intrusions. It is based on unsupervised machine learning. Trained by regular request data system detects outlier user parameters. Since training is not reliant on previous knowledge of SQL injections, t...

  3. The Optical Design of the PEP-II Injection Beamlines

    CERN Document Server

    Fieguth, T

    1996-01-01

    The optical design of the PEP-II electron and positron Injection Beamlines is described. Use of the existing high power, low emittance beams available from the SLC damping rings require that pulsed extraction of 9.0 GeV electrons and 3.1 GeV positrons for injection into the PEP-II rings occur in the early sectors of the accelerator. More than 5 kilometers of new beam transport lines have been designed and are being constructed to bring these beams to their respective rings. The optical design maximizes the tolerance to errors especially to those contributing to beam size and position jitter. Secondly, the design minimizes costs by utilizing existing components or component designs and minimizing the number required. Here we discuss important attributes including choice of lattice, specification of error tolerances, including errors in construction, alignment, field errors, power supply stability, and orbit correction.

  4. The Optical Design of the PEP-II Injection Beamlines

    Energy Technology Data Exchange (ETDEWEB)

    Fieguth, Ted

    2003-05-23

    The optical design of the PEP-II electron and positron Injection Beamlines is described. Use of the existing high power, low emittance beams available from the SLC damping rings require that pulsed extraction of 9.0 GeV electrons and 3.1 GeV positrons for injection into the PEP-II rings occur in the early sectors of the accelerator. More than 5 kilometers of new beam transport lines have been designed and are being constructed to bring these beams to their respective rings. The optical design maximizes the tolerance to errors especially to those contributing to beam size and position jitter. Secondly, the design minimizes costs by utilizing existing components or component designs and minimizing the number required. Here we discuss important attributes including choice of lattice, specification of error tolerances, including errors in construction, alignment, field errors, power supply stability, and orbit correction.

  5. Joint and Soft Tissue Injections

    Science.gov (United States)

    ... Injections Joint and Soft Tissue Injections Share Print What is a joint and soft tissue injection? Joint and soft tissue injections are shots ... many injections do I need and how often? What restrictions do I have after an ... tissue injection, treatment April 1, 2004 Copyright © American Academy ...

  6. LHC Report: Towards stable beams and collisions

    CERN Multimedia

    CERN Bulletin

    2011-01-01

    Over the past two weeks, the LHC re-commissioning with beam has continued at a brisk pace. The first collisions of 2011 were produced on 2 March, with stable beams and collisions for physics planned for the coming days. Low intensity beams with just a few bunches of particles were used to test the energy ramp to 3.5 TeV and the squeeze. The results were successful and, as a by-product, the first collisions of 2011 were recorded 2 March. One of the main activities carried out by the operation teams has been the careful set-up of the collimation system, and the injection and beam dump protection devices. The collimation system provides essential beam cleaning, preventing stray particles from impacting other elements of the machine, particularly the superconducting magnets. In addition to the collimation system, also the injection and beam dump protection devices perform a vital machine protection role, as they detect any beam that might be mis-directed during rare, but not totally unavoidable, hardware hiccups...

  7. MULTI-OBJECTIVE ONLINE OPTIMIZATION OF BEAM LIFETIME AT APS

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yipeng

    2017-06-25

    In this paper, online optimization of beam lifetime at the APS (Advanced Photon Source) storage ring is presented. A general genetic algorithm (GA) is developed and employed for some online optimizations in the APS storage ring. Sextupole magnets in 40 sectors of the APS storage ring are employed as variables for the online nonlinear beam dynamics optimization. The algorithm employs several optimization objectives and is designed to run with topup mode or beam current decay mode. Up to 50\\% improvement of beam lifetime is demonstrated, without affecting the transverse beam sizes and other relevant parameters. In some cases, the top-up injection efficiency is also improved.

  8. Piezoelectric Injection Systems

    Science.gov (United States)

    Mock, R.; Lubitz, K.

    The origin of direct injection can be doubtlessly attributed to Rudolf Diesel who used air assisted injection for fuel atomisation in his first self-ignition engine. Although it became apparent already at that time that direct injection leads to reduced specific fuel consumption compared to other methods of fuel injection, it was not used in passenger cars for the moment because of its disadvantageous noise generation as the requirements with regard to comfort were seen as more important than a reduced specific consumption.

  9. Dumping the decelerated beams of CLIC

    CERN Document Server

    Jeanneret, Bernard

    2011-01-01

    The spent drive beam must be cleanly extracted and bent away from the decelerator axis at the end of each CLIC decelerator in order to leave space for injecting a fresh beam train in the next sector. Then the spent beam must be safely absorbed. A compact extraction system made of a single dipole is proposed. The spent beam is driven to a water dump located at 20m downstream of the extraction point and transversely 6m away of the axis of the main linac. An adequate spread of the beam impact map on the dump offers small temperature excursions in both the dump and its entrance window, allowing for reliable operation and a long lifetime of the system.

  10. Plasma heating by a relativistic electron beam

    International Nuclear Information System (INIS)

    Janssen, G.C.A.M.

    1983-01-01

    This thesis is devoted to the interaction of a Relativistic Electron Beam (REB) with a plasma. The goal of the experiment described herein is to study in detail the mechanism of energy transfer from the beam to the plasma. The beam particles have an energy of 800 keV, a current of 6 kA, a diameter of 3 cm and an adjustable pulse length of 50-150 ns. This beam is injected into cold hydrogen and helium plasmas with densities ranging from 10 18 to 10 20 m -3 . First, the technical aspects of the experiment are described. Then measurements on the hf fields excited by the REB-plasma are presented (optical line profiles and spectra of beam electrons). The final section is devoted to plasma heating. (Auth.)

  11. Top-up injection schemes for future circular lepton collider

    Science.gov (United States)

    Aiba, M.; Goddard, B.; Oide, K.; Papaphilippou, Y.; Saá Hernández, Á.; Shwartz, D.; White, S.; Zimmermann, F.

    2018-02-01

    Top-up injection is an essential ingredient for the future circular lepton collider (FCC-ee) to maximize the integrated luminosity and it determines the design performance. In ttbar operation mode, with a beam energy of 175 GeV, the design lifetime of ∼1 h is the shortest of the four anticipated operational modes, and the beam lifetime may be even shorter in actual operation. A highly robust top-up injection scheme is consequently imperative. Various top-up methods are investigated and a number of suitable schemes are considered in developing alternative designs for the injection straight section of the collider ring. For the first time, we consider multipole-kicker off-energy injection, for minimizing detector background in top-up operation, and the use of a thin wire septum in a lepton storage ring, for maximizing the luminosity.

  12. Injection Protection Upgrade for the HL-LHC

    CERN Document Server

    AUTHOR|(CDS)2067108; Biancacci, Nicolo; 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.

  13. A clustered H2 beam

    International Nuclear Information System (INIS)

    Marcri, M.

    1984-01-01

    This chapter discusses the construction of a clustered H2 beam to obtain - pp interactions using the p beam produced in A.A. and stored via P.S. in ring 2 of ISR in order to perform an experimental study of charmonium states (experiment R 704 at the CERN ISR). Topics covered include the choice of the nozzle, the H2 injection circuit, the pumping system, measurement and controls, and actual status. A luminosity of 10 31 cm -2 sec -1 can be achieved using a circulating beam of 3x10 11- p and a target of H2 1.75x10 -10 g/cm 2 thick. The use of converging-diverging nozzles is effective for the production of very intense beams of clusters of H2 molecules. Differential pumping stages are needed to keep the pressure in the ISR ring down to acceptable values for the operation of the machine (pumping system of the ISR, beam lifetime, signal to noise ratio)

  14. Recent improvements of the RF Beam control for LHC-type beams in the CERN PS

    CERN Document Server

    Damerau, H; Schokker, M

    2010-01-01

    To cope with the large variety of different beams for the LHC, the RF beam control in the CERN PS has evolved continuously to improve its flexibility and reliability. Single-bunch beams, several different multi-bunch beams with 25, 50 or 75 ns bunch spacing at ejection for LHC filling, as well as two lead-ion beam variants are now regularly produced in pulse-to-pulse operation. The multibunch beam control for protons can be easily re-adjusted from 0.25 · 1011 to 1.3 · 1011 particles per ejected bunch. Depending on the number of bunches injected from the PS Booster, the length of the ejected bunch train may vary from 8 to 72 bunches. This paper summarizes recent improvements in the low-level RF systems and gives an outlook on the future consolidation.

  15. Transverse Phase Space Painting for SNS Accumulator Ring Injection

    International Nuclear Information System (INIS)

    Beebe-Wang, J.; Lee, Y. Y.; Raparia, D.; Wei, J.

    1999-01-01

    The result of investigation and comparison of a series of transverse phase space painting schemes for the injection of SNS accumulator ring 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 are presented and discussed

  16. Saturne II: characteristics of the proton beam, field qualities and corrections, acceleration of the polarized protons

    International Nuclear Information System (INIS)

    Laclare, J.-L.

    1978-01-01

    Indicated specifications of Saturne II are summed up: performance of the injection system, quality of the guidance field (magnetic measurements and multipolar corrections), transverse and longitudinal instabilities, characteristics of the beam stored in the machine and of the extracted beam. The problem of depolarization along the acceleration cycle is briefly discussed (1 or 2% between injection and 3 GeV) [fr

  17. Electrostatic injection kicker for the KEK digital accelerator

    Directory of Open Access Journals (Sweden)

    Toshikazu Adachi

    2013-05-01

    Full Text Available An electrostatic injection kicker (ES-Kicker has been developed and installed in the KEK digital accelerator, which is a synchrotron aimed at accelerating all ion species. The ES-Kicker kicks an injected ion beam horizontally into the ring orbit and consists of two main electrodes for electric field generation and three intermediate electrodes to correct field homogeneity. In our single-turn injection scheme, the circulating beam and the injected beam both pass through the electrode aperture of the kicker, so the kicker field must be turned off before arrival of the first circulating beam. The ES-Kicker is therefore operated in a pulse mode. This means that the excitation circuit for the ES-Kicker must be carefully designed, since the falling edge of the electric field is strongly affected by parasitic capacitance of this circuit, and any remaining field may disturb the circulating beam. This paper describes performance of the ES-Kicker on the basis of simulations and measurement results.

  18. Beam studies at the SPEAR3 synchrotron using a digital optical mask

    Science.gov (United States)

    Zhang, H. D.; Fiorito, R. B.; Corbett, J.; Shkvarunets, A. G.; Tian, K.; Fisher, A.

    2016-05-01

    The 3GeV SPEAR3 synchrotron light source operates in top-up injection mode with up to 500 mA circulating in the storage ring (equivalently 392 nC). Each injection pulse contains 40-80 pC producing a contrast ratio between total stored charge and injected charge of about 6500:1. In order to study transient injected beam dynamics during user operations, it is desirable to optically image the injected pulse in the presence of the bright stored beam. In the present work this is done by imaging the visible component of the synchrotron radiation onto a digital micro-mirror-array device (DMD), which is then used as an optical mask to block out light from the bright central core of the stored beam. The physical masking, together with an asynchronously-gated, ICCD imaging camera, makes it possible to observe the weak injected beam component on a turn-by-turn basis. The DMD optical masking system works similar to a classical solar coronagraph but has some distinct practical advantages: i.e. rapid adaption to changes in the shape of the stored beam, a high extinction ratio for unwanted light and minimum scattering from the primary beam into the secondary optics. In this paper we describe the DMD masking method, features of the high dynamic range point spread function for the SPEAR3 optical beam line and measurements of the injected beam in the presence of the stored beam.

  19. Beam studies at the SPEAR3 synchrotron using a digital optical mask

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, H. D.; Fiorito, R. B.; Corbett, J.; Shkvarunets, A. G.; Tian, K.; Fisher, A.

    2016-05-01

    The 3GeV SPEAR3 synchrotron light source operates in top-up injection mode with up to 500 mA circulating in the storage ring (equivalently 392 nC). Each injection pulse contains 40–80 pC producing a contrast ratio between total stored charge and injected charge of about 6500:1. In order to study transient injected beam dynamics during user operations, it is desirable to optically image the injected pulse in the presence of the bright stored beam. In the present work this is done by imaging the visible component of the synchrotron radiation onto a digital micro-mirror-array device (DMD), which is then used as an optical mask to block out light from the bright central core of the stored beam. The physical masking, together with an asynchronously-gated, ICCD imaging camera, makes it possible to observe the weak injected beam component on a turn-by-turn basis. The DMD optical masking system works similar to a classical solar coronagraph but has some distinct practical advantages: i.e. rapid adaption to changes in the shape of the stored beam, a high extinction ratio for unwanted light and minimum scattering from the primary beam into the secondary optics. In this paper we describe the DMD masking method, features of the high dynamic range point spread function for the SPEAR3 optical beam line and measurements of the injected beam in the presence of the stored beam.

  20. Design study of electrostatic inflector in compact cyclotron injection system

    International Nuclear Information System (INIS)

    Zhang Tianjue; Fan Mingwu

    1996-01-01

    The beam dynamics behaviour in electrostatic inflector is investigated for a vertical type injection system to a compact cyclotron. The computer aided design and matching of the inflector are based on the simulation of computed beam orbit. Modeling and simulation are done on PC-486 to form a software package. The software package can be used to develop a new type cyclotron design combining with the software package CYCCAE developed by China Institute of Atomic Energy three years ago

  1. Proton beam source

    International Nuclear Information System (INIS)

    Auslender, V.L.; Lazarev, V.N.; Panfilov, A.D.

    1979-01-01

    A proton pulse source with penning discharge and a cathode needle in the discharge chamber is described. The source is simple in design and has a great service life. An electromagnet induces a magnetic field of the order of 700 Oe along the axis of the discharge chamber. In this field the discharge is ignited between the left and right cathodes when a positive voltage is applied to the anode. A hole in the recess of the right cathode serves to provide the injection of plasma into the accelerating gap. The cathodes and the anode unit are set into a sleeve welded to magnet poles. Through a magnetic circuit this unit is placed on a high-voltage ceramic insulator. For extraction and initial shaping of an ion beam with a divergence angle of 3 0 use is made of extraction electrodes which form the Pierce optics. Further shaping of the ion beam is realized by an electrostatic lens. Tungsten grids in the holes of grounded electrodes increase the focusing effect of the lens. At the input of the first accelerating gap of an accelerator the described source provides an ion peak current of 140 mA at 65% content of protons and a normalized emittance of no more than 4x10 -5 cmxrad

  2. Unstable Electrostatic Ion Cyclotron Waves Exited by an Ion Beam

    DEFF Research Database (Denmark)

    Michelsen, Poul; Pécseli, Hans; Juul Rasmussen, Jens

    1976-01-01

    Electrostatic ion cyclotron waves were observed in a quiescent cesium plasma into which a low‐energy beam of sodium ions was injected. The instability appeared when the beam velocity was above 12 times the ion thermal velocity. The waves propagated along the magnetic field with a velocity somewhat...

  3. Beam transport through electrostatic accelerators and matching into post accelerators

    International Nuclear Information System (INIS)

    Larson, J.D.

    1986-01-01

    Ion beam transport through electrostatic acceleration is briefly reviewed. Topics discussed include injection, matching into the low-energy acceleration stage, matching from the terminal stripper into the high-energy stage, transport to a post accelerator, space charge, bunching isochronism, dispersion and charge selection. Beam transport plans for the proposed Vivitron accelerator are described. (orig.)

  4. Measuring beam losses in the THI project

    International Nuclear Information System (INIS)

    David, L.; Duneau, P.; Lecorche, E.; Lermine, P.; Lemaitre, E.; Ulrich, M.

    1997-01-01

    The goal of the THI project (High Intensity Transport) is to upgrade the GANIL facilities by increasing the beam by a factor of 15, at least for light ions. This higher intensity is required by the radioactive beam facility SPIRAL starting in September 1997, to generate the new nuclear species in the solid target-source (ISOL method). For the control system, the most important issues are now to tune the accelerators while minimizing the beam losses at each stage of acceleration and when not possible, to have a fast beam loss detection signal. This system is composed of probes which deliver a signal to stop the beam when there's too much intensity lost and when not, a logarithmic value of the beam intensity. These probes are linked to a front end VME crate on the network, and in the control room, on the workstations, a graphical user interface program displays the beam variations using logarithmic scales. This program is also used to center the beam while injecting in or ejecting from the main cyclotrons by tuning the steerers, the magnetic elements inside, and the electrostatic deflector to be able to separate and extract the last beam turn. (author)

  5. Computer control of the ISX-B neutral injection beamlines

    International Nuclear Information System (INIS)

    Hanna, P.C.

    1982-09-01

    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

  6. Plasma heating by cluster injection: basic features and expected behaviour

    International Nuclear Information System (INIS)

    Bottiglioni, F.; Coutant, J.; Fois, M.

    1976-08-01

    The main components of a cluster injection line intended for plasma heating is briefly discussed, that is the beam source, the cluster ionizer and the accelerating tube, as well as the behavior of clusters interacting with a plasma. Outlines of the experiment of cluster injection into TFR, in progress at Fontenay-aux-Roses, and expected results will be presented and discussed all along the paper

  7. Channel of Axial Injection of DC-60 Cyclotron

    CERN Document Server

    Gikal, B N; Bogomolov, S L; Borisenko, A N; Borisov, O N; Gulbekyan, G G; Ivanenko, I A; Kalagin, I V; Kazacha, V I; Kazarinov, N Yu; Khabarov, M V; Lysukhin, S N; Melnikov, V N; Paschenko, S V; Tikhomirov, A V

    2006-01-01

    The design study and realization of the axial injection beam line of DC-60 cyclotron constructed at the Flerov Laboratory of Nuclear Reactions of the Joint Institute for Nuclear Research are given. The channel allows one to transport and to inject into the cyclotron ions with mass-to-charge ratio $A/Z$ being within interval A/Z=6-12 and kinetic energy up to 17 $Z/A$ keV/m.u.

  8. Beam divergence scaling in neutral beam injectors

    International Nuclear Information System (INIS)

    Holmes, A.J.T.

    1976-01-01

    One of the main considerations in the design of neutral beam injectors is to monimize the divergence of the primary ion beam and hence maximize the beam transport and minimize the input of thermal gas. Experimental measurements of the divergence of a cylindrical ion beam are presented and these measurements are used to analyze the major components of ion beam divergence, namely: space charge expansion, gas-ion scattering, emittance and optical aberrations. The implication of these divergence components in the design of a neutral beam injector system is discussed and a method of maximizing the beam current is described for a given area of source plasma

  9. Beam screens for the LHC beam pipes

    CERN Multimedia

    Patrice Loïez

    1997-01-01

    Cross-section of LHC prototype beam pipes showing the beam screens. Slits in the screens allow residual gas molecules to be pumped out and become frozen to the walls of the ultra-cold beam pipe. Beam screens like these have been designed to line the beam pipes, absorbing radiation before it can hit the magnets and warm them up, an effect that would greatly reduce the magnetic field and cause serious damage.

  10. Electron injection in microtron

    International Nuclear Information System (INIS)

    Axinescu, S.

    1977-01-01

    A review of the methods of injecting electrons in the microtron is presented. A special attention is paid to efficient injection systems developed by Wernholm and Kapitza. A comparison of advantages and disadvantages of both systems is made in relation to the purpose of the microtron. (author)

  11. Glenohumeral Joint Injections

    Science.gov (United States)

    Gross, Christopher; Dhawan, Aman; Harwood, Daniel; Gochanour, Eric; Romeo, Anthony

    2013-01-01

    Context: Intra-articular injections into the glenohumeral joint are commonly performed by musculoskeletal providers, including orthopaedic surgeons, family medicine physicians, rheumatologists, and physician assistants. Despite their frequent use, there is little guidance for injectable treatments to the glenohumeral joint for conditions such as osteoarthritis, adhesive capsulitis, and rheumatoid arthritis. Evidence Acquisition: We performed a comprehensive review of the available literature on glenohumeral injections to help clarify the current evidence-based practice and identify deficits in our understanding. We searched MEDLINE (1948 to December 2011 [week 1]) and EMBASE (1980 to 2011 [week 49]) using various permutations of intra-articular injections AND (corticosteroid OR hyaluronic acid) and (adhesive capsulitis OR arthritis). Results: We identified 1 and 7 studies that investigated intra-articular corticosteroid injections for the treatment of osteoarthritis and adhesive capsulitis, respectively. Two and 3 studies investigated the use of hyaluronic acid in osteoarthritis and adhesive capsulitis, respectively. One study compared corticosteroids and hyaluronic acid injections in the treatment of osteoarthritis, and another discussed adhesive capsulitis. Conclusion: Based on existing studies and their level of evidence, there is only expert opinion to guide corticosteroid injection for osteoarthritis as well as hyaluronic acid injection for osteoarthritis and adhesive capsulitis. PMID:24427384

  12. Tolerability of hypertonic injectables.

    Science.gov (United States)

    Wang, Wei

    2015-07-25

    Injectable drug products are ideally developed as isotonic solutions. Often, hypertonic injectables may have to be marketed for a variety of reasons such as product solubilization and stabilization. A key concern during product formulation development is the local and systemic tolerability of hypertonic products upon injection. This report reviews and discusses the tolerability in terms of local discomfort, irritation, sensation of heat and pain, along with other observed side effects of hypertonicity in both in-vitro systems and in-vivo animal and human models. These side effects clearly depend on the degree of hypertonicity. The sensation of pain among different injection routes seems to follow this order: intramuscular>subcutaneous>intravenous or intravascular. It is recommended that the upper osmolality limit should be generally controlled under 600 mOsm/kg for drug products intended for intramuscular or subcutaneous injection. For drug products intended for intravenous or intravascular injection, the recommended upper limit should be generally controlled under 1,000 mOsm/kg for small-volume injections (≤ 100 mL) and 500 mOsm/kg for large-volume injections (>100mL). Several options are available for minimization of hypertonicity-induced pain upon product administration. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. First results of space charge simulations for the novel multi-turn injection

    CERN Document Server

    Giovannozzi, M; George, M

    2010-01-01

    Recently, a novel multi-turn injection technique was proposed. It is based on beam merging via resonance crossing. The various beamlets are successively injected and merged back by crossing a stable resonance generated by non-linear magnetic fields. Space charge is usually a crucial effect at injection in a circular machine and it could have an adverse impact on the phase space topology required for merging the various beamlets. Numerical simulations were performed to assess the stability of the merging process as a function of injected beam charge. The results are presented and discussed in this paper.

  14. Beam geometry selection using sequential beam addition.

    Science.gov (United States)

    Popple, Richard A; Brezovich, Ivan A; Fiveash, John B

    2014-05-01

    The selection of optimal beam geometry has been of interest since the inception of conformal radiotherapy. The authors report on sequential beam addition, a simple beam geometry selection method, for intensity modulated radiation therapy. The sequential beam addition algorithm (SBA) requires definition of an objective function (score) and a set of candidate beam geometries (pool). In the first iteration, the optimal score is determined for each beam in the pool and the beam with the best score selected. In the next iteration, the optimal score is calculated for each beam remaining in the pool combined with the beam selected in the first iteration, and the best scoring beam is selected. The process is repeated until the desired number of beams is reached. The authors selected three treatment sites, breast, lung, and brain, and determined beam arrangements for up to 11 beams from a pool comprised of 25 equiangular transverse beams. For the brain, arrangements were additionally selected from a pool of 22 noncoplanar beams. Scores were determined for geometries comprised equiangular transverse beams (EQA), as well as two tangential beams for the breast case. In all cases, SBA resulted in scores superior to EQA. The breast case had the strongest dependence on beam geometry, for which only the 7-beam EQA geometry had a score better than the two tangential beams, whereas all SBA geometries with more than two beams were superior. In the lung case, EQA and SBA scores monotonically improved with increasing number of beams; however, SBA required fewer beams to achieve scores equivalent to EQA. For the brain case, SBA with a coplanar pool was equivalent to EQA, while the noncoplanar pool resulted in slightly better scores; however, the dose-volume histograms demonstrated that the differences were not clinically significant. For situations in which beam geometry has a significant effect on the objective function, SBA can identify arrangements equivalent to equiangular

  15. Beam geometry selection using sequential beam addition

    Energy Technology Data Exchange (ETDEWEB)

    Popple, Richard A., E-mail: rpopple@uabmc.edu; Brezovich, Ivan A.; Fiveash, John B. [Department of Radiation Oncology, The University of Alabama at Birmingham, 1720 2nd Avenue South, Birmingham, Alabama 35294 (United States)

    2014-05-15

    Purpose: The selection of optimal beam geometry has been of interest since the inception of conformal radiotherapy. The authors report on sequential beam addition, a simple beam geometry selection method, for intensity modulated radiation therapy. Methods: The sequential beam addition algorithm (SBA) requires definition of an objective function (score) and a set of candidate beam geometries (pool). In the first iteration, the optimal score is determined for each beam in the pool and the beam with the best score selected. In the next iteration, the optimal score is calculated for each beam remaining in the pool combined with the beam selected in the first iteration, and the best scoring beam is selected. The process is repeated until the desired number of beams is reached. The authors selected three treatment sites, breast, lung, and brain, and determined beam arrangements for up to 11 beams from a pool comprised of 25 equiangular transverse beams. For the brain, arrangements were additionally selected from a pool of 22 noncoplanar beams. Scores were determined for geometries comprised equiangular transverse beams (EQA), as well as two tangential beams for the breast case. Results: In all cases, SBA resulted in scores superior to EQA. The breast case had the strongest dependence on beam geometry, for which only the 7-beam EQA geometry had a score better than the two tangential beams, whereas all SBA geometries with more than two beams were superior. In the lung case, EQA and SBA scores monotonically improved with increasing number of beams; however, SBA required fewer beams to achieve scores equivalent to EQA. For the brain case, SBA with a coplanar pool was equivalent to EQA, while the noncoplanar pool resulted in slightly better scores; however, the dose-volume histograms demonstrated that the differences were not clinically significant. Conclusions: For situations in which beam geometry has a significant effect on the objective function, SBA can identify

  16. Design of four-beam IH-RFQ linear accelerator

    Science.gov (United States)

    Ikeda, Shota; Murata, Aki; Hayashizaki, Noriyosu

    2017-09-01

    The multi-beam acceleration method is an acceleration technique for low-energy high-intensity heavy ion beams, which involves accelerating multiple beams to decrease space charge effects, and then integrating these beams by a beam funneling system. At the Tokyo Institute of Technology a two beam IH-RFQ linear accelerator was developed using a two beam laser ion source with direct plasma injection scheme. This system accelerated a carbon ion beam with a current of 108 mA (54 mA/channel × 2) from 5 up to 60 keV/u. In order to demonstrate that a four-beam IH-RFQ linear accelerator is suitable for high-intensity heavy ion beam acceleration, we have been developing a four-beam prototype. A four-beam IH-RFQ linear accelerator consists of sixteen RFQ electrodes (4 × 4 set) with stem electrodes installed alternately on the upper and lower ridge electrodes. As a part of this development, we have designed a four-beam IH-RFQ linear accelerator using three dimensional electromagnetic simulation software and beam tracking simulation software. From these simulation results, we have designed the stem electrodes, the center plate and the side shells by evaluating the RF properties such as the resonance frequency, the power loss and the electric strength distribution between the RFQ electrodes.

  17. Longitudinal Beam measurements at the LHC: The LHC Beam Quality Monitor

    CERN Document Server

    Papotti, G; Follin, F; Wehrle, U

    2011-01-01

    The LHC Beam Quality Monitor is a system that measures individual bunch lengths and positions, similarly to the twin system SPS Beam Quality Monitor, from which it was derived. The pattern verification that the system provides is vital during the injection process to verify the correctness of the injected pattern, while the bunch length measurement is fed back to control the longitudinal emittance blow up performed during the energy ramp and provides a general indication of the health of the RF system. The algorithms used, the hardware implementation and the system integration in the LHC control infrastructure are presented in this paper, along with possible improvements.

  18. Stable beams

    CERN Multimedia

    2015-01-01

    Stable beams: two simple words that carry so much meaning at CERN. When LHC page one switched from "squeeze" to "stable beams" at 10.40 a.m. on Wednesday, 3 June, it triggered scenes of jubilation in control rooms around the CERN sites, as the LHC experiments started to record physics data for the first time in 27 months. This is what CERN is here for, and it’s great to be back in business after such a long period of preparation for the next stage in the LHC adventure.   I’ve said it before, but I’ll say it again. This was a great achievement, and testimony to the hard and dedicated work of so many people in the global CERN community. I could start to list the teams that have contributed, but that would be a mistake. Instead, I’d simply like to say that an achievement as impressive as running the LHC – a machine of superlatives in every respect – takes the combined effort and enthusiasm of everyone ...

  19. LHC Damper Beam commissioning in 2010

    CERN Document Server

    Höfle, W; Schokker, M; Valuch, D

    2011-01-01

    The LHC transverse dampers were commissioned in 2010 with beam and their use at injection energy of 450 GeV, during the ramp and in collisions at 3.5 TeV for Physics has become part of the standard operations pro- cedure. The system proved important to limit emittance blow-up at injection and to maintain smaller than nominal emittances throughout the accelerating cycle. We describe the commissioning of the system step-by-step as done in 2010 and summarize its performance as achieved for pro- ton as well as ion beams in 2010. Although its principle function is to keep transverse oscillations under control, the system has also been used as an exciter for abort gap clean- ing and tune measurement. The dedicated beam position measurement system with its low noise properties provides additional possibilities for diagnostics.

  20. Investigation of APS PAR Vertical Beam Instability

    CERN Document Server

    Yao, Chihyuan; Sereno, Nicholas S; Yang Bing Xin

    2005-01-01

    The Advanced Photon Source (APS) particle accumulator ring (PAR) is a 325-MeV storage ring that collects and compresses linac pulse trains into a single bunch for booster injection. A vertical beam instability has been observed when only a single linac bunch is injected and the total beam charge is from 0.15 to 0.7 nC. The instability starts about 80 ms after the injection, lasts about 160 ms, and is highly reproducible. We performed spectral measurement and time-resolved imaging with both a gated-intensified camera and a streak camera in order to characterize this instability. Initial analysis of the data indicates that the instability is due to ion trapping. A stable lattice was established as result of the investigation. This report summarizes the experimental results and gives some preliminary analysis.

  1. Beam measurements of the SPS longitudinal impedance

    CERN Document Server

    Lasheen, A

    2017-01-01

    Longitudinal instabilities are one of the main limitationsin the CERN SPS to reach the beam parameters requiredfor the High Luminosity LHC project. In preparation tothe SPS upgrade, possible remedies are studied by perform-ing macroparticle simulations using the machine impedancemodel obtained from electromagnetic simulations and mea-surements. To benchmark the impedance model, the resultsof simulations are compared with various beam measure-ments. In this study, the reactive part of the impedance wasprobed by measuring the quadrupole frequency shift withintensity, obtained from bunch length oscillations at mis-matched injection into the SPS. This method was appliedover many last years to follow up the evolution of the SPSimpedance, injecting bunches with the same bunch length.A novel approach, giving significantly more information,consists in varying the injected bunch length. The compari-son of these measurements with macroparticle simulationsallowed to test the existing model and identify some missingSPS i...

  2. Injection and transfer lines of the PS Booster

    CERN Multimedia

    Photographic Service

    1972-01-01

    In the foreground is the vacuum chamber for the 50 MeV proton beam coming from the Linac. The tank held by white frames houses the "Vertical Distributor", which deflects the Linac beam to the levels of the Booster's 4 superposed rings. After acceleration in the Booster, originally to 800 MeV, today to 1.4 GeV, the beams from the 4 rings are combined in the vertical plane and transfered to the 26 GeV PS. The "Recombination Line", intersecting the injection line, crosses the picture from left to right.

  3. Continuous multiple injections at the Fermilab Main Injector

    Directory of Open Access Journals (Sweden)

    K. Y. Ng

    2002-06-01

    Full Text Available Instead of slip stacking, an alternate method of doubling the linear intensity of the Fermilab Main Injector is discussed. This method makes use of rf barriers to transfer 12 booster batches from the Fermilab Booster to the Main Injector in 12 consecutive booster cycles, totaling 800 ms. After that, adiabatic capture of the beam into 53 MHz buckets can be accomplished in about 10 ms. Because the beam is debunched during the injection process and no rf voltage is required, the beam loading voltages in the rf cavities are small and can be eliminated by a combination of counterphasing and mechanical shorts.

  4. Accelerated Electron-Beam Formation with a High Capture Coefficient in a Parallel Coupled Accelerating Structure

    Science.gov (United States)

    Chernousov, Yu. D.; Shebolaev, I. V.; Ikryanov, I. M.

    2018-01-01

    An electron beam with a high (close to 100%) coefficient of electron capture into the regime of acceleration has been obtained in a linear electron accelerator based on a parallel coupled slow-wave structure, electron gun with microwave-controlled injection current, and permanent-magnet beam-focusing system. The high capture coefficient was due to the properties of the accelerating structure, beam-focusing system, and electron-injection system. Main characteristics of the proposed systems are presented.

  5. Construction and characterization of valve for fast gas injection

    International Nuclear Information System (INIS)

    Ueda, M.; Rossi, J.O.; Aso, Y.; Mangueira, L.S.; Pereira, C.A.

    1989-01-01

    An electromagnetic valve for fast gas injection was built and characterized. This type of gas injection valve has been routinely applied to various plasma experiments: in magnetic confinement devices as TOKAMAK, RFP and Compact Toroids as well as intense ion beam and neutral particle generators. The valve is capable of injecting gas pulses with up to 80 m Torr peak pressure, rising time < 400 μs and duration time of 40 ms, in the present experimental set-up. It is easy to build and its components can be totally acquired in the country. (author)

  6. Space Charge Compensation in the Linac4 Low Energy Beam Transport Line with Negative Hydrogen Ions

    CERN Document Server

    Valerio-Lizarraga, C; Leon-Monzon, I; Lettry, J; Midttun, O; Scrivens, R

    2014-01-01

    The space charge effect of low energy, unbunched ion beams can be compensated by the trapping of ions or electrons into the beam potential. This has been studied for the 45 keV negative hydrogen ion beam in the CERN Linac4 Low Energy Beam Tranport (LEBT) using the package IBSimu1, which allows the space charge calculation of the particle trajectories. The results of the beam simulations will be compared to emittance measurements of an H- beam at the CERN Linac4 3 MeV test stand, where the injection of hydrogen gas directly into the beam transport region has been used to modify the space charge compensation degree.

  7. Propagation of a nonrelativistic electron beam in a plasma in a magnetic field

    International Nuclear Information System (INIS)

    Okuda, H.; Horton, R.; Ono, M.; Ashour-Abdalla, M.

    1986-10-01

    Propagation of a nonrelativistic electron beam in a plasma in a strong magnetic field has been studied using electrostatic one-dimensional particle simulation models. Electron beams of finite pulse length and of continuous injection are followed in time to study the effects of beam-plasma interaction on the beam propagation. For the case of pulsed beam propagation, it is found that the beam distribution rapidly spreads in velocity space generating a plateaulike distribution with a high energy tail extending beyond the initial beam velocity

  8. MD2190: Q" Stabilization during injection

    CERN Document Server

    Schenk, Michael; Li, Kevin Shing Bruce; Malina, Lukas; Metral, Elias; Tomas Garcia, Rogelio; CERN. Geneva. ATS Department

    2018-01-01

    This MD is a follow-up study of MD1831, where single bunches were stabilized against impedance-driven instabilities at 6.5 TeV in the LHC with Q''. The goals are (i) to explore whether an amplitude detuning free Q'' knob can be implemented at injection energy, and (ii) whether Q'' can provide beam stability at injection, where the beams suffer mostly from electron cloud effects. Ideally, this would relax the use of the Landau octupoles and may help in preserving the beam quality by reducing dynamic aperture limitations originating from the octupoles. The MD has been split into two parts: First, optics corrections were put in place to minimize beta-beating and linear coupling introduced by the knobs. The corrections were achieved by means of orbit bumps and skew quadrupole knobs. Machine safety was then validated with loss maps. While the betatron loss maps were approved, the off-momentum maps showed a priori unexpected losses in several arcs and the MD was stopped at this point for reasons of machine protecti...

  9. The Injection System of SAGA Light Source

    CERN Document Server

    Iwasaki, Yoshitaka; Ohgaki, Hideaki; Okajima, Toshihiro; Takabayashi, Yuichi; Tomimasu, Takio; Yoshida, Katuhide

    2005-01-01

    Saga light Source is a 1.4-GeV electron storage ring with a circumference of 75.6m. The injector is a 250-MeV linac producing 1 ms macro-pulse with a peak current of 12mA and repetition rate of 1Hz. The output beam from the linac is transported though a transport line, and injected into the ring though a septum magnet with a bending angle of 20-degree. The transport line consists of two bending magnets, two quadrupole doublelets, and a quadrupole singlet. The bump orbit is formed by four kicker magnets, two of which are installed at both sides of septum magnet, and other two are positioned apart by one magnet cell of the ring. They are excited by sinusoidal electric currents with a half width of 0.5 ms. The beam optics for the injection trajectory is computed and shown at control room, the parameters for which are provided directly from the power supply control server PC. The operator is able to see real-time result of the beam trajectory calculation. This tool is quite effective to optimize the magnets param...

  10. Injection and laser acceleration of ions based on the resonant surface photoionization

    International Nuclear Information System (INIS)

    Antsiferov, V.V.; Smirnov, G.I.; Telegin, G.G.

    1993-01-01

    The collective effects have been investigated of the injection and acceleration of the ion beams due to the resonant surface photoionization. The considered scheme of the laser accelerator allows to obtain positive ions with relativistic velocities. 11 refs., 2 figs

  11. ELECTRON CLOUD AT COLLIMATOR AND INJECTION REGION OF THE SPALLATION NEUTRON SOURCE ACCUMULATOR RING

    International Nuclear Information System (INIS)

    WANG, L.; HSEUH, H.-C.; LEE, Y.Y.; RAPARIA, D.; WEI, J.; COUSINEAU, S.

    2005-01-01

    The beam loss along the Spallation Neutron Source's accumulator ring is mainly located at the collimator region and injection region. This paper studied the electron cloud build-up at these two regions with the three-dimension program CLOUDLAND

  12. 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...

  13. Relativistic electron beam source with an air-core step-up transformer

    International Nuclear Information System (INIS)

    Mohri, Akihiro; Ikuta, Kazunari; Masuzaki, Masaru; Tsuzuki, Tetsuya; Fujiwaka, Setsuya.

    1975-04-01

    An air-core step-up transformer with a high coupling factor has been developed to generate a high voltage pulse for charging the pulse forming line of a relativistic electron beam source. A beam source using the transformer was constructed and well operated for the beam injection into a toroidal system. (auth.)

  14. Beam-beam effects in the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Shiltsev, V.; Alexahin, Y.; Lebedev, V.; Lebrun, P.; Moore, R.S.; Sen, T.; Tollestrup, A.; Valishev, A.; Zhang, X.L.; /Fermilab

    2005-01-01

    The Tevatron in Collider Run II (2001-present) is operating with 6 times more bunches, many times higher beam intensities and luminosities than in Run I (1992-1995). Electromagnetic long-range and head-on interactions of high intensity proton and antiproton beams have been significant sources of beam loss and lifetime limitations. We present observations of the beam-beam phenomena in the Tevatron and results of relevant beam studies. We analyze the data and various methods employed in operations, predict the performance for planned luminosity upgrades, and discuss ways to improve it.

  15. Crystalline beams

    International Nuclear Information System (INIS)

    Schiffer, J.P.

    1989-01-01

    Ions in a storage ring are confined to a mean orbit by focusing elements. To a first approximation these may be described by a constant harmonic restoring force: F = -Kr. If the particles in the frame moving along with the beam have small random thermal energies, then they will occupy a cylindrical volume around the mean orbit and the focusing force will be balanced by that from the mutual repulsion of the particles. Inside the cylinder only residual two-particle interactions will play a significant role and some form of ordering might be expected to take place. The results of some of the first MD calculations showed a surprising result: not only were the particles arranged in the form of a tube, but they formed well-defined layers: concentric shells, with the particles in each shell arranged in a hexagonal lattice that is characteristic of two-dimensional Coulomb systems. This paper discusses the condense layer structure

  16. New ORNL neutral beam transport system

    International Nuclear Information System (INIS)

    Stirling, W.L.; Davis, R.C.; Haselton, H.H.; Schnechter, D.E.; Tsai, C.C.

    1977-01-01

    The Princeton Large Torus (PLT) neutral beam injection systems have proven themselves to be a solid foundation on which next generation systems can be based. There are two areas in the new systems receiving particular emphasis: (a) increased power per beam line and (b) higher beam transmission efficiency. Two different methods are being investigated to improve the transmission efficiency. First the drift tube region, the region of the beam line between the vacuum chamber housing the ion source and the torus, is being enlarged. In this manner a second, large cryopump will be installed in the drift tube to lower the pressure to approx.10 -5 torr. Thus, neutral beam reionization on the background gas will be significantly reduced from the measured losses at a few 10 -4 torr of the PLT system. Second, the beam divergence will be reduced by application of one or more of three known techniques developed on a single aperture source in the laboratory. Each of these methods has shown a reduction in single beamlet divergence from theta/sub HWHM/ approx. 1 0 to approx.0.5 0 . The low beamlet divergence coupled with a differentially pumped drift tube will effectively accommodate the larger ion sources under development. All future beam line systems will benefit either directly or indirectly from the experience gained operating and upgrading the PLT beam line concept

  17. On finding the analytic dependencies of the external field potential on the control function when optimizing the beam dynamics

    Science.gov (United States)

    Ovsyannikov, A. D.; Kozynchenko, S. A.; Kozynchenko, V. A.

    2017-12-01

    When developing a particle accelerator for generating the high-precision beams, the injection system design is of importance, because it largely determines the output characteristics of the beam. At the present paper we consider the injection systems consisting of electrodes with given potentials. The design of such systems requires carrying out simulation of beam dynamics in the electrostatic fields. For external field simulation we use the new approach, proposed by A.D. Ovsyannikov, which is based on analytical approximations, or finite difference method, taking into account the real geometry of the injection system. The software designed for solving the problems of beam dynamics simulation and optimization in the injection system for non-relativistic beams has been developed. Both beam dynamics and electric field simulations in the injection system which use analytical approach and finite difference method have been made and the results presented in this paper.

  18. Remarks on micro-instabilities and injected beams

    International Nuclear Information System (INIS)

    Henning, J.J.

    1979-01-01

    In this paper the linear dispersion theory is briefly summarized and the Fokker-Planck equation is solved for general initial conditions. General remarks on the possibilities for the existence of electrostatic instabilities in the presence of a magnetic field are also given

  19. CERN Accelerator School - Beam injection, extraction and transfer

    CERN Multimedia

    2016-01-01

    Registration is now open for the CERN Accelerator School’s specialised course to be held in Erice, Italy, from 10 to 19 March, 2017.   The course will be of interest to staff and students in accelerator laboratories, university departments and companies manufacturing accelerator who wish to learn about accelerator science and technology. Further information can be found at: http://indico.cern.ch/event/451905/ http://cas.web.cern.ch/cas/IET2017/IET-advert.html

  20. Experimental study of the dependence of beam current on injection ...

    Indian Academy of Sciences (India)

    Abstract. 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 ...

  1. Beam-beam instability driven by wakefield effects in linear colliders

    CERN Document Server

    Brinkmann, R; Schulte, Daniel

    2002-01-01

    The vertical beam profile distortions induced by wakefield effects in linear colliders (the so-called ``banana effect'') generate a beam-beam instability at the collision point when the vertical disruption parameter is large. We illustrate this effect in the case of the TESLA linear collider project. We specify the tolerance on the associated emittance growth, which translates into tolerances on injection jitter and, for a given tuning procedure, on structure misalignments. We look for possible cures based on fast orbit correction at the interaction point and using a fast luminosity monitor.

  2. Active stabilization of a diode laser injection lock

    Energy Technology Data Exchange (ETDEWEB)

    Saxberg, Brendan; Plotkin-Swing, Benjamin; Gupta, Subhadeep [Department of Physics, University of Washington, P.O. Box 351560, Seattle, Washington 98195-1560 (United States)

    2016-06-15

    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.

  3. 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.

  4. Active stabilization of a diode laser injection lock

    International Nuclear Information System (INIS)

    Saxberg, Brendan; Plotkin-Swing, Benjamin; 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.

  5. Parathyroid Hormone Injection

    Science.gov (United States)

    ... the blood in people with certain types of hypoparathyroidism (condition in which the body does not produce ... are taking this medication.Parathyroid hormone injection controls hypoparathyroidism but does not cure it. Continue to use ...

  6. 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.

  7. Premixed direct injection disk

    Science.gov (United States)

    York, William David; Ziminsky, Willy Steve; Johnson, Thomas Edward; Lacy, Benjamin; Zuo, Baifang; Uhm, Jong Ho

    2013-04-23

    A fuel/air mixing disk for use in a fuel/air mixing combustor assembly is provided. The disk includes a first face, a second face, and at least one fuel plenum disposed therebetween. A plurality of fuel/air mixing tubes extend through the pre-mixing disk, each mixing tube including an outer tube wall extending axially along a tube axis and in fluid communication with the at least one fuel plenum. At least a portion of the plurality of fuel/air mixing tubes further includes at least one fuel injection hole have a fuel injection hole diameter extending through said outer tube wall, the fuel injection hole having an injection angle relative to the tube axis. The invention provides good fuel air mixing with low combustion generated NOx and low flow pressure loss translating to a high gas turbine efficiency, that is durable, and resistant to flame holding and flash back.

  8. Endoscopic injection therapy

    Directory of Open Access Journals (Sweden)

    Sang Woon Kim

    2017-06-01

    Full Text Available Since the U.S. Food and Drug Administration approved dextranomer/hyaluronic acid copolymer (Deflux for the treatment of vesicoureteral reflux, endoscopic injection therapy using Deflux has become a popular alternative to open surgery and continuous antibiotic prophylaxis. Endoscopic correction with Deflux is minimally invasive, well tolerated, and provides cure rates approaching those of open surgery (i.e., approximately 80% in several studies. However, in recent years a less stringent approach to evaluating urinary tract infections (UTIs and concerns about long-term efficacy and complications associated with endoscopic injection have limited the use of this therapy. In addition, there is little evidence supporting the efficacy of endoscopic injection therapy in preventing UTIs and vesicoureteral reflux-related renal scarring. In this report, we reviewed the current literature regarding endoscopic injection therapy and provided an updated overview of this topic.

  9. Endoscopic injection therapy

    Science.gov (United States)

    Kim, Sang Woon; Lee, Yong Seung

    2017-01-01

    Since the U.S. Food and Drug Administration approved dextranomer/hyaluronic acid copolymer (Deflux) for the treatment of vesicoureteral reflux, endoscopic injection therapy using Deflux has become a popular alternative to open surgery and continuous antibiotic prophylaxis. Endoscopic correction with Deflux is minimally invasive, well tolerated, and provides cure rates approaching those of open surgery (i.e., approximately 80% in several studies). However, in recent years a less stringent approach to evaluating urinary tract infections (UTIs) and concerns about long-term efficacy and complications associated with endoscopic injection have limited the use of this therapy. In addition, there is little evidence supporting the efficacy of endoscopic injection therapy in preventing UTIs and vesicoureteral reflux-related renal scarring. In this report, we reviewed the current literature regarding endoscopic injection therapy and provided an updated overview of this topic. PMID:28612059

  10. Piperacillin and Tazobactam Injection

    Science.gov (United States)

    ... cause infection. Tazobactam is in a class called beta-lactamase inhibitor. It works by preventing bacteria from destroying piperacillin.Antibiotics such as piperacillin and tazobactam injection will ... your risk of getting an infection later that resists antibiotic treatment.

  11. Neutral beams for magnetic fusion

    International Nuclear Information System (INIS)

    Hooper, B.

    1977-01-01

    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 (10 14 particles/cm 3 ) 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

  12. C-stop production by micro injection moulding

    DEFF Research Database (Denmark)

    Islam, Aminul

    of engineering micro product which integrate many features like beam snapfit, annular snapfit, hinge connection, filter grid, house, lid etc in a single product. All the features are in micro dimensional scale and manufactured by single step of injection moulding. This presentation will cover industrial...

  13. Innards of a New Injection Septum for the PS Booster

    CERN Multimedia

    CERN PhotoLab

    1974-01-01

    The original injection septum was replaced by this new one, of improved design. It is really 4 septum magnets, for the 4 levels of the Booster rings, mounted on a common structure and housed in a single tank. The 50 MeV proton beam from the linac enters the visible septum aperture and moves from right to left.

  14. Stripping foils for the PSB H- injection system

    CERN Document Server

    Aiba, M; Goddard, B; Weterings, W

    2009-01-01

    Beam physics considerations for the stripping foil of the PSB H- injection system are described, including the arguments for the foil type, thickness, geometry and positioning. The foil performance considerations are described, including expected stripping efficiency, emittance growth, energy straggling, temperature and lifetime. The required movement ranges and tolerances are detailed, together with the assumptions used.

  15. 200 MeV RF linac for synchrotron injection

    International Nuclear Information System (INIS)

    Whitham, K.; Anamkath, H.; Lyons, S.; Manca, J.; Miller, R.; Treas, P.; Zante, T.; Miller, R.

    1992-01-01

    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

  16. Transmission of the Neutral Beam Heating Beams at TJ-II; Transmision del Haz de Neutros de Calentamiento en TJ-II

    Energy Technology Data Exchange (ETDEWEB)

    Fuentes Lopez, C.

    2007-09-27

    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.

  17. Dimethyl Ether Injection Studies

    DEFF Research Database (Denmark)

    Sorenson, Spencer C.; Glensvig, Michael; Abata, Duane L.

    1998-01-01

    A series of preliminary investigations has been performed in order to investigate the behavior of DME in a diesel injection environment. These studies have in-cluded visual observations of the spray penetration and angles for high pressure injection into Nitrogen using conventional jerk pump inje...... well with the experimentally observed combustion rates during the mixing controlled portions of the combustion in a naturally aspirated direct injection diesel engine.......A series of preliminary investigations has been performed in order to investigate the behavior of DME in a diesel injection environment. These studies have in-cluded visual observations of the spray penetration and angles for high pressure injection into Nitrogen using conventional jerk pump...... injection equipment. It was shown that the penetration of the DME spray can be predicted with the methods developed for diesel fuel by Hiroyasu and co-workers. Some anomalies in spray shape, such as rapid lateral spreading at the base of the spray and spray bifurcation have been observed.The compressibility...

  18. Beam halo in high-intensity beams

    International Nuclear Information System (INIS)

    Wangler, T.P.

    1993-01-01

    In space-charge dominated beams the nonlinear space-charge forces produce a filamentation pattern, which in projection to the 2-D phase spaces results in a 2-component beam consisting of an inner core and a diffuse outer halo. The beam-halo is of concern for a next generation of cw, high-power proton linacs that could be applied to intense neutron generators for nuclear materials processing. The author describes what has been learned about beam halo and the evolution of space-charge dominated beams using numerical simulations of initial laminar beams in uniform linear focusing channels. Initial results are presented from a study of beam entropy for an intense space-charge dominated beam

  19. Neutralisation and transport of negative ion beams: physics and diagnostics

    Science.gov (United States)

    Serianni, G.; Agostinetti, P.; Agostini, M.; Antoni, V.; Aprile, D.; Baltador, C.; Barbisan, M.; Brombin, M.; Cavenago, M.; Chitarin, G.; Dalla Palma, M.; Delogu, R.; Fellin, F.; Fonnesu, N.; Marconato, N.; Pasqualotto, R.; Pimazzoni, A.; Sartori, E.; Spagnolo, S.; Spolaore, M.; Veltri, P.; Zaniol, B.; Zaupa, M.

    2017-04-01

    Neutral beam injection is one of the most important methods of plasma heating in thermonuclear fusion experiments, allowing the attainment of fusion conditions as well as driving the plasma current. Neutral beams are generally produced by electrostatically accelerating ions, which are neutralised before injection into the magnetised plasma. At the particle energy required for the most advanced thermonuclear devices and particularly for ITER, neutralisation of positive ions is very inefficient so that negative ions are used. The present paper is devoted to the description of the phenomena occurring when a high-power multi-ampere negative ion beam travels from the beam source towards the plasma. Simulation of the trajectory of the beam and of its features requires various numerical codes, which must take into account all relevant phenomena. The leitmotiv is represented by the interaction of the beam with the background gas. The main outcome is the partial neutralisation of the beam particles, but ionisation of the background gas also occurs, with several physical and technological consequences. Diagnostic methods capable of investigating the beam properties and of assessing the relevance of the various phenomena will be discussed. Examples will be given regarding the measurements collected in the small flexible NIO1 source and regarding the expected results of the prototype of the neutral beam injectors for ITER. The tight connection between measurements and simulations in view of the operation of the beam is highlighted.

  20. Beam-front dynamics and ion acceleration in drifting intense relativistic electron beams

    International Nuclear Information System (INIS)

    Alexander, K.F.; Hintze, W.

    1976-01-01

    Collective ion acceleration at the injection of a relativistic electron beam into a low-pressure gas or a plasma is discussed and its strong dependence on the beam-front dynamics is shown. A simple one-dimensional model taking explicitly into account the motion and ionizing action of the ions in the beam-front region is developed for the calculation of the beam drift velocity. The obtained pressure dependence is in good agreement with experimental data. The energy distribution is shown of the ions accelerated in the moving potential well of the space charge region. Scaling laws for the beam-front dynamics and ion acceleration are derived. (J.U.)

  1. Impact of Distributed Injection on Plasma Wakefield Acceleration at FACET

    Science.gov (United States)

    Vafaei-Najafabadi, Navid

    2017-10-01

    Impact of Distributed Injection on Plasma Wakefield Acceleration at FACET An electron-beam-driven plasma wakefield accelerator (PWFA) will sustain accelerating gradients of tens of GeV/m in a meter-scale plasma. If the transverse radius of the electron beam is not matched to the plasma, the envelope of this drive beam will execute betatron oscillations in the focusing force of the ion column. At its lowest radius in this oscillation cycle, the electric field of the beam can surpass the ionization threshold of elements, leading to ionization injection of these electrons in to the wake. Electrons from each cycle of this betatron oscillation then accumulate at the back of the wake and decrease the accelerating field. The experiments were carried out at FACET, where the drive electron beam had 3 nC of charge and an energy of 20.35 GeV. Two different plasma sources were used: a 30 cm self-ionized Rubidium (Rb) vapor confined by argon (Ar) gas at room-temperature and a partially pre-ionized hydrogen gas. The experimental and simulation evidence for the distributed injection of electrons and their impact on the PWFA at FACET will be presented in this talk. This work was supported by NSF Grant No. PHY-1415386 and DOE Grant No. DE-SC0010064. Work at SLAC was supported by DOE Contract No. DE-AC02-76SF00515.

  2. Systems and methods of varying charged particle beam spot size

    Science.gov (United States)

    Chen, Yu-Jiuan

    2014-09-02

    Methods and devices enable shaping of a charged particle beam. A modified dielectric wall accelerator includes a high gradient lens section and a main section. The high gradient lens section can be dynamically adjusted to establish the desired electric fields to minimize undesirable transverse defocusing fields at the entrance to the dielectric wall accelerator. Once a baseline setting with desirable output beam characteristic is established, the output beam can be dynamically modified to vary the output beam characteristics. The output beam can be modified by slightly adjusting the electric fields established across different sections of the modified dielectric wall accelerator. Additional control over the shape of the output beam can be excreted by introducing intentional timing de-synchronization offsets and producing an injected beam that is not fully matched to the entrance of the modified dielectric accelerator.

  3. Approach to increase beam intensity extracted from a cyclotron

    Science.gov (United States)

    Nakao, M.; Hojo, S.; Katagiri, K.; Miyahara, N.; Noda, A.; Noda, K.; Sugiura, A.; Wakui, T.; Smirnov, V.; Vorozhtsov, S.; Goto, A.

    2017-09-01

    To increase the beam intensity of cyclotrons used for producing radionuclides, beam loss during extraction must be reduced. Extraction efficiency is limited by the beam parameters in front of the deflector, especially angular distribution. Computer simulation of the second harmonic mode for 18 MeV protons, which is frequently used, has been carried out to understand beam behavior in a cyclotron. The extraction efficiency is determined by the width of the angular distribution of particles in the phase space plot at the deflector. An effective method to reduce the width is to shorten the bunch at injection. The simulation shows that the bunch phase length at injection must be ⩽30° to realize a 30 μA extraction beam current and satisfy the deflector heat limit of 200 W.

  4. Beam Loss Monitors for NSLS-II Storage Ring

    International Nuclear Information System (INIS)

    Kramer, S.L.; Cameron, P.

    2011-01-01

    The shielding for the NSLS-II storage ring will provide adequate protection for the full injected beam losses in two cells of the ring around the injection point, but the remainder of the ring is shielded for lower losses of <10% top-off injection beam current. This will require a system to insure that beam losses do not exceed levels for a period of time that could cause excessive radiation exposure outside the shield walls. This beam Loss Control and Monitoring system will have beam loss monitors that will measure where the beam charge is lost around the ring, to warn operators if losses approach the design limits. To measure the charge loss quantitatively, we propose measuring the electron component of the shower as beam electrons hit the vacuum chamber (VC) wall. This will be done using the Cerenkov light as electrons transit ultra-pure fused silica rods placed close to the inner edge of the VC. The entire length of the rod will collect light from the electrons of the spread out shower resulting from the small glancing angle of the lost beam particles to the VC wall. The design and measurements results of the prototype Cerenkov BLM will be presented.

  5. SPS Beam Steering for LHC Extraction

    CERN Document Server

    Gianfelice Wendt, E; Cornelis, K; Norderhaug Drosdal, L; Goddard, B; Kain, V; Meddahi, M; Papaphilippou, Y; Wenninger, J

    2014-01-01

    Beside producing beams for fixed target operation, the CERN Super Proton Synchrotron (SPS) accelerates beams for injection into the Large Hadron Collider (LHC). During the 2012-2013 run drifts of the extracted beam horizontal trajectories have been observed and lengthy optimizations in the transfer lines were performed to reduce particle losses. The observed trajectory drifts are consistent with the measured SPS orbit drifts at extraction. The feasibility of an automatic beam steering towards a “golden” orbit at the extraction septa, has been therefore investigated. The challenges and constraints related to the implementation of such a correction in the SPS are described. Simulation results are presented and a possible operational steering strategy is proposed. As the observed drift is mainly horizontal, the horizontal plane only will be considered.

  6. Trapping of gun-injected plasma by a tokamak

    International Nuclear Information System (INIS)

    Leonard, A.W.; Dexter, R.N.; Sprott, J.C.

    1987-01-01

    It has been seen that a plasma produced by a Marshall gun can be injected into and trapped by a tokamak plasma. This trapping of a gun-injected plasma is explained in terms of a depolarization current mechanism. A model is developed that describes the slowing of a plasma beam crossing into the magnetic field of a tokamak. The slowing down time is shown to go as tau/sub s/proportionalT/sup 3/2//sub e/L 2 /n/sub b/α 2 0 , where n/sub b/ and T/sub e/ are the density and temperature of the plasma beam and α 0 /L is the pitch of the field lines per unit length in the direction in which the beam is traveling. Experimental tests of this model are consistent with the scaling predictions

  7. Development of KSTAR Neutral Beam Heating System

    Energy Technology Data Exchange (ETDEWEB)

    Oh, B. H.; Song, W. S.; Yoon, B. J. (and others)

    2007-10-15

    The prototype components of a neutral beam injection (NBI) system have been developed for the KSTAR, and a capability of the manufactured components has been tested. High power ion source, acceleration power supply, other ion source power supplies, neutralizer, bending magnet for ion beam separation, calorimeter, and cryo-sorption pump have been developed by using the domestic technologies and tested for a neutral beam injection of 8 MW per beamline with a pulse duration of 300 seconds. The developed components have been continuously upgraded to achieve the design requirements. The development technology of high power and long pulse neutral beam injection system has been proved with the achievement of 5.2 MW output for a short pulse length and 1.6 MW output for a pulse length of 300 seconds. Using these development technologies, the domestic NB technology has been stabilized under the development of high power ion source, NB beamline components, high voltage and current power supplies, NB diagnostics, NB system operation and control.

  8. Injectable Multiple Sclerosis Medications

    Science.gov (United States)

    Tran, Zung Vu

    2012-01-01

    Although injection-site reactions (ISRs) occur with US Food and Drug Administration–approved injectable disease-modifying therapies (DMTs) for multiple sclerosis, there are currently few reports of real-world data on ISR management strategies or possible correlations between ISRs and patient demographics, disease characteristics, and missed injections. Patient-reported data on the use of DMTs, patient demographic and disease characteristics, missed injections, and ISR reduction strategies were collected via e-mail, a patient registry (www.ms-cam.org), and a Web-based survey. Of the 1380 respondents, 1201 (87%) indicated that they had used injectable DMTs, of whom 377 (31%) had used intramuscular (IM) interferon beta-1a (IFNβ-1a), 172 (14%) had used subcutaneous (SC) IFNβ-1a, 183 (15%) had used SC IFNβ-1b, and 469 (39%) had used glatiramer acetate (GA). The majority of respondents were older (73% were ≥40 years), female (79%), married or living with a partner (72%), white (94%), and nonsmoking (82%). Injection-site reaction incidence, grouped according to severity, varied among DMTs, with IM IFNβ-1a causing significantly (P ISRs than the other therapies. Female sex and younger age were significantly (P ISRs among users of IM IFNβ-1a, SC IFNβ-1b, and GA. Nonwhites reported severe ISRs more often than whites. For all DMTs injection-site massage and avoidance of sensitive sites were the most frequently used strategies to minimize ISRs. These data may help identify patients with characteristics associated with a higher risk for ISRs, allowing health-care professionals to provide anticipatory guidance to patients at risk for decreased adherence or discontinuation. PMID:24453732

  9. SIMULATIONS OF BOOSTER INJECTION EFFICIENCY FOR THE APS-UPGRADE

    Energy Technology Data Exchange (ETDEWEB)

    Calvey, J.; Borland, M.; Harkay, K.; Lindberg, R.; Yao, C.-Y.

    2017-06-25

    The APS-Upgrade will require the injector chain to provide high single bunch charge for swap-out injection. One possible limiting factor to achieving this is an observed reduction of injection efficiency into the booster synchrotron at high charge. We have simulated booster injection using the particle tracking code elegant, including a model for the booster impedance and beam loading in the RF cavities. The simulations point to two possible causes for reduced efficiency: energy oscillations leading to losses at high dispersion locations, and a vertical beam size blowup caused by ions in the Particle Accumulator Ring. We also show that the efficiency is much higher in an alternate booster lattice with smaller vertical beta function and zero dispersion in the straight sections.

  10. Time dependence of microsecond intense electron beam transport in gases

    International Nuclear Information System (INIS)

    Lucey, R.F. Jr.; Gilgenback, R.M.; Tucker, J.E.; Brake, M.L.; Enloe, C.L.; Repetti, T.E.

    1987-01-01

    The authors present results of long-pulse (0.5 μs) electron beam propagation in the ion focused regime (IFR). Electron beam parameters are 800 kV with several hundred amperes injected current. For injection into air (from 0.7 mTorr to 75 mTorr) and helium (from 14 mTorr to 227 mTorr) the authors observe a ''time-dependent propagation window'' in which efficient (up to 100%) propagation starts at a time comparable to the electron impact ionization time needed to achieve n/sub i/ -- (1/γ/sup 2/)n/sub eb/. The transport goes abruptly to zero about 50-150 ns after this initial propagation. This is followed by erratic propagation often consisting of numerous narrower pulses 10-40 ns wide. In these pulses the transported current can be 100% of the injected current, but is generally lower. As the fill pressure is increased, there are differences in the propagated beam pulse, which can be summarized as follows: 1) the temporal occurrence of the beam propagation window shifts to earlier times, 2) the propagated beam current has much faster risetimes, 3) a larger portion of the injected beam is propagated. Similar results are observed when the electron beam is propagated in helium. However, at a given pressure, the beam transport window occurs at later times and exhibits a slower risetime. These effects are consistent with electron beam-induced ionization. Experiments are being performed to determine if the observed beam instability is due to the ion hose instability or streaming instability

  11. 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.

  12. Syringe injectable electronics

    Science.gov (United States)

    Hong, Guosong; Zhou, Tao; Jin, Lihua; Duvvuri, Madhavi; Jiang, Zhe; Kruskal, Peter; Xie, Chong; Suo, Zhigang; Fang, Ying; Lieber, Charles M.

    2015-01-01

    Seamless and minimally-invasive three-dimensional (3D) 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 syringe injection and subsequent unfolding of submicrometer-thick, centimeter-scale macroporous mesh electronics through needles with a diameter as small as 100 micrometers. 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 3D structures, including (i) monitoring of internal mechanical strains in polymer cavities, (ii) tight integration and low chronic immunoreactivity with several distinct regions of the brain, and (iii) in vivo multiplexed neural recording. Moreover, syringe injection enables delivery of flexible electronics through a rigid shell, 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. PMID:26053995

  13. Concept design of the axial injection system of type CYCIAE cyclotrons

    International Nuclear Information System (INIS)

    Xiao Meiqin; Zhang Tianjue; Fan Mingwu

    1996-01-01

    Beam optics properties of the axial injection system of CYCIAE30 is calculated and compared with operation results to show that the theory and the calculation method used are reasonable. Then, the concept design of the axial injection system of CYCIAE 70 is made and optimization results are obtained

  14. Study on space charge compensation in negative hydrogen ion beam

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, A. L.; Chen, J. E. [University of Chinese Academy of Sciences, Beijing 100049 (China); State Key Laboratory of Nuclear Physics and Technology, Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871 (China); Peng, S. X., E-mail: sxpeng@pku.edu.cn; Ren, H. T.; Zhang, T.; Zhang, J. F.; Xu, Y.; Guo, Z. Y. [State Key Laboratory of Nuclear Physics and Technology, Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871 (China)

    2016-02-15

    Negative hydrogen ion beam can be compensated by the trapping of ions into the beam potential. When the beam propagates through a neutral gas, these ions arise due to gas ionization by the beam ions. However, the high neutral gas pressure may cause serious negative hydrogen ion beam loss, while low neutral gas pressure may lead to ion-ion instability and decompensation. To better understand the space charge compensation processes within a negative hydrogen beam, experimental study and numerical simulation were carried out at Peking University (PKU). The simulation code for negative hydrogen ion beam is improved from a 2D particle-in-cell-Monte Carlo collision code which has been successfully applied to H{sup +} beam compensated with Ar gas. Impacts among ions, electrons, and neutral gases in negative hydrogen beam compensation processes are carefully treated. The results of the beam simulations were compared with current and emittance measurements of an H{sup −} beam from a 2.45 GHz microwave driven H{sup −} ion source in PKU. Compensation gas was injected directly into the beam transport region to modify the space charge compensation degree. The experimental results were in good agreement with the simulation results.

  15. Electron beam control for barely separated beams

    Energy Technology Data Exchange (ETDEWEB)

    Douglas, David R.; Ament, Lucas J. P.

    2017-04-18

    A method for achieving independent control of multiple beams in close proximity to one another, such as in a multi-pass accelerator where coaxial beams are at different energies, but moving on a common axis, and need to be split into spatially separated beams for efficient recirculation transport. The method for independent control includes placing a magnet arrangement in the path of the barely separated beams with the magnet arrangement including at least two multipole magnets spaced closely together and having a multipole distribution including at least one odd multipole and one even multipole. The magnetic fields are then tuned to cancel out for a first of the barely separated beams to allow independent control of the second beam with common magnets. The magnetic fields may be tuned to cancel out either the dipole component or tuned to cancel out the quadrupole component in order to independently control the separate beams.

  16. Literature in Focus Beta Beams: Neutrino Beams

    CERN Multimedia

    2009-01-01

    By Mats Lindroos (CERN) and Mauro Mezzetto (INFN Padova, Italy) Imperial Press, 2009 The beta-beam concept for the generation of electron neutrino beams was first proposed by Piero Zucchelli in 2002. The idea created quite a stir, challenging the idea that intense neutrino beams only could be produced from the decay of pions or muons in classical neutrino beams facilities or in future neutrino factories. The concept initially struggled to make an impact but the hard work by many machine physicists, phenomenologists and theoreticians over the last five years has won the beta-beam a well-earned position as one of the frontrunners for a possible future world laboratory for high intensity neutrino oscillation physics. This is the first complete monograph on the beta-beam concept. The book describes both technical aspects and experimental aspects of the beta-beam, providing students and scientists with an insight into the possibilities o...

  17. AECL IMPELA electron beam industrial irradiators

    International Nuclear Information System (INIS)

    Labrie, J.P.; Drewell, N.H.; Ebrahim, N.A.; Lawrence, C.B.; Mason, V.A.; Ungrin, J.; White, B.F.

    1989-01-01

    A family of industrial irradiators is being developed by AECL to cover an electron-beam energy range from 5 to 18 MeV at beam powers between 20 and 250 kW. The IMPELA family of irradiators is designed for push button, reliable operation. The major irradiator components are modular, allowing for later upgrades to meet increased demands in either electron or X-ray mode. Interface between the control system, irradiator availability and dose quality assurance is in conformance with the most demanding specifications. The IMPELA irradiators use a klystron-driven, standing-wave, L-band accelerator structure with direct injection from a rugged, triode electron gun. Direct control of the accelerating field during the beam pulse ensures constant output beam energy, independent of beam power. The first member of the family, the IMPELA 10/50 (10 MeV, 50 kW), is in the final stages of assembly at Chalk River Nuclear Laboratories. The IMPELA 10/50 is constructed around a 3.25 m long, high-power-capacity accelerator structure operated at a duty factor of 5%. Beam loading exceeds 60%. The rf power is provided by a 2 MW/150 kW modulated-anode klystron protected from load mismatches by a circulator. This prototype will be used to demonstrate the reliability and dose uniformity targets of the IMPELA family. Full beam operation of the IMPELA 10/50 is scheduled for early 1989. (orig.)

  18. Beam Transfer Systems for the LAGUNA-LBNO Long Baseline Neutrino Beam from the CERN SPS

    CERN Document Server

    Goddard, B; Efthymiopoulos, I; Papaphilippou, Y; Parfenova, A

    2013-01-01

    For the Long Baseline neutrino facility under study at CERN (LAGUNA-LBNO) it is initially planned to extract a 400 GeV beam from the second long straight section in the SPS into the existing transfer channel TT20 leading to the North Area experimental zone, to a new target aligned with a far detector at a distance of 2300 km [1]. In a second phase a new High-Power Proton Synchrotron (HPPS) accelerator is proposed, to give a 2 MW beam at about 50 GeV on the same target. In this paper the required beam transfer systems are outlined, including the new sections of transfer line between the Superconducting Proton Linac (SPL), HP-PS and SPS, and from the SPS to the target, and also the injection and extraction systems in the long straight section of the HPPS. The feasibility of a 4 GeV H- injection system is discussed.

  19. Reactor water injection facility

    Energy Technology Data Exchange (ETDEWEB)

    Yoshikawa, Kazuhiro; Kinoshita, Shoichiro

    1997-05-02

    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.)

  20. LLRF beam results on the first year of ELENA’s commissioning with beam

    CERN Document Server

    Angoletta, Maria Elena; Molendijk, John; Sanchez Quesada, Jorge; CERN. Geneva. ATS Department

    2018-01-01

    CERN’s Extra Low ENergy Antiproton (ELENA) ring’s commissioning with beam started in earnest in March 2017. Ions from an H- source were injected in ELENA at low energy, although in a degraded way (lower voltage and intensity than planned) and with not constant reproducibility of the injection. From August 2017 onwards antiprotons from the AD were also injected in ELENA at high energy for up to three, weekly MD session. The 2017 ELENA commissioning run stopped on December 1st to allow the installation of the electron cooler. This note gives an overview of the successful operation carried out by the ELENA Low-Level RF (LLRF) during the first year of ELENA commissioning and of the main beam results obtained. Operation with H- ions and with antiprotons are considered, together with different operational settings and problems encountered. Hints on future deployment and commissioning steps are also provided.

  1. Reconstruction of negative hydrogen ion beam properties from beamline diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Ruf, Benjamin

    2014-09-25

    For the experimental fusion reactor ITER, which should show the feasibility of sustaining a fusion plasma with a positive power balance, some technology still has to be developed, amongst others also the plasma heating system. One heating technique is the neutral beam injection (NBI). A beam of fast deuterium atoms is injected into the fusion plasma. By heavy particle collisions the beam particles give their energy to the plasma. A NBI system consists of three major components. First, deuterium ions are generated in a low temperature, low pressure plasma of an ion source. At ITER, the requirements on the beam energy of 1 MeV cause the necessity of negative charged deuterium ions. Secondly, the ions are accelerated within an acceleration system with several grids, where the plasma grid is the first grid. The grids are on different descending high voltage potentials. The source itself is on the highest negative potential. Thirdly, the fast deuterium ions have to be neutralised. This thesis deals with the second step in the mentioned beam system, the ion acceleration and beam formation. The underlying experiments and measurements were carried out at the testbeds BATMAN (BAvarianTest MAchine for Negative ions) and ELISE (Extraction from a Large Ion Source Experiment) at the Max-Planck-Institut fuer Plasmaphysik Garching (IPP Garching). The main goal of this thesis is to provide a tool which allows the determination of the beam properties. These are beam divergence, stripping losses and beam inhomogeneity. For this purpose a particle trajectory code has been developed from scratch, namely BBC-NI (Bavarian Beam Code for Negative Ions). The code is able to simulate the whole beam and the outcome of several beam diagnostic tools. The data obtained from the code together with the measurements of the beam diagnostic tools should allow the reconstruction of the beam properties. The major beam diagnostic tool, which is used in this thesis, is the beam emission spectroscopy

  2. ISR beam scrapers

    CERN Multimedia

    CERN PhotoLab

    1972-01-01

    Beam scrapers seen in the direction of the beam. The two horizontal scraper foils are near the centre of the beam pipe andthe two scrapers for protection of the vacuum chamber are further outside. In the lower part of the beam pipe is the vertical halo scraping blade.

  3. Telecommunication using muon beams

    International Nuclear Information System (INIS)

    Arnold, R.C.

    1976-01-01

    Telecommunication is effected by generating a beam of mu mesons or muons, varying a property of the beam at a modulating rate to generate a modulated beam of muons, and detecting the information in the modulated beam at a remote location

  4. Analysis of orthotropic beams

    Science.gov (United States)

    Jen Y. Liu; S. Cheng

    1979-01-01

    A plane-stress analysis of orthotropic or isotropic beams is presented. The loading conditions considered are: (1) a concentrated normal load arbitrarily located on the beam, and (2) a distributed normal load covering an arbitrary length of the beam. exhibit close agreement with existing experimental data from Sitka spruce beams. Other loading conditions can similarly...

  5. Telecommunication using muon beams

    Science.gov (United States)

    Arnold, Richard C.

    1976-01-01

    Telecommunication is effected by generating a beam of mu mesons or muons, varying a property of the beam at a modulating rate to generate a modulated beam of muons, and detecting the information in the modulated beam at a remote location.

  6. A concept for canceling the leakage field inside the stored beam chamber of a septum magnet

    Science.gov (United States)

    Abliz, M.; Jaski, M.; Xiao, A.; Jain, A.; Wienands, U.; Cease, H.; Borland, M.; Decker, G.; Kerby, J.

    2018-04-01

    The Advanced Photon Source (APS) is planning to upgrade its storage ring from a double-bend achromat to a multi-bend achromat lattice as part of the APS Upgrade Project (APS-U). A swap-out injection scheme is planned for the APS-U in order to keep the beam current constant and to reduce the dynamic aperture requirements. The injection scheme, combined with the constraints in the booster to storage ring transfer region of the APS-U, results in requiring a septum magnet which deflects the injected 6 GeV electron beam by 89 mrad, while not appreciably disturbing the stored beam. The proposed magnet is straight; however, it is rotated in yaw, roll, and pitch from the stored beam chamber to meet the on-axis swap-out injection requirements for the APS-U lattice. The concept utilizes cancellation of the leakage field inside the 8 mm x 6 mm super-ellipsoidal stored beam chamber. As a result, the horizontal deflection angle of the 6 GeV stored beam is reduced to less than 1 μrad with only a 2-mm-thick septum separating the stored beam and the 1.06 T field seen by the injected beam. This design also helps to minimize the integrated skew quadrupole and normal sextupole fields inside the stored beam chamber.

  7. Ion beam processing of surgical materials

    Science.gov (United States)

    Williams, James M.; Buchanan, Raymond A.; Lee, In-Seop

    1989-02-01

    Ion beam processing has now achieved a secure place in surface treatment of biomaterials. This development is largely a result of the success of the process for wear prevention of orthopedic Ti-alloy in rubbing contact with ultrahigh molecular-weight polyethylene. Basic contributions of the authors in this area, together with other pertinent literature will be reviewed. Research in ion beam processing of biomaterials is turning to other areas. Among these, bioelectronics is considered to be a promising area for further effort. Pertinent experiments on effects of implantation of iridium into titanium and Ti-6Al-4V alloy on corrosion and charge injection properties are presented.

  8. First circulating beam in the AA

    CERN Multimedia

    CERN PhotoLab

    1980-01-01

    On 3 July 1980, two years after project authorization, beam circulated for the first time in the AA. It was a 3.56 GeV/c proton test beam. We see an expecting crowd, minutes before the happy event. The persons are too numerous to name them all, but the 3 most prominent ones are at the centre (left to right): Roy Billinge (Joint AA Project Leader, with his hand on the control box), Eifionydd Jones (white shirt), Simon van der Meer (spiritus rector and Joint AA Project Leader). The first antiprotons were injected, made to circulate and cooled soon after, on 14 July 1980.

  9. Electron beam charge state amplifier (EBQA)--a conceptual evaluation

    International Nuclear Information System (INIS)

    Dooling, J. C.

    1998-01-01

    A concept is presented for stripping low-energy, radioactive ions from 1+ to higher charge states. Referred to as an Electron Beam Charge State Amplifier (EBQA), this device accepts a continuous beam of singly-charged, radioactive ions and passes them through a high-density electron beam confined by a solenoidal magnetic field. Singly-charged ions may be extracted from standard Isotope-Separator-Online (ISOL) sources. An EBQA is potentially useful for increasing the charge state of ions prior to injection into post-acceleration stages at ISOL radioactive beam facilities. The stripping efficiency from q=1+ to 2+ (η 12 ) is evaluated as a function of electron beam radius at constant current with solenoid field, injected ion energy, and ion beam emittance used as parameters. Assuming a 5 keV, 1 A electron beam, η 12 = 0.38 for 0.1 keV, 132 Xe ions passing through an 8 Tesla solenoid, 1 m in length. Multi-pass configurations to achieve 3+ or 4+ charge states are also conceivable. The calculated efficiencies depend inversely on the initial ion beam emittances. The use of a helium-buffer-gas, ion-guide stage to improve the brightness of the 1+ beams [1] may enhance the performance of an EBQA

  10. LANSCE beam current limiter

    International Nuclear Information System (INIS)

    Gallegos, F.R.

    1996-01-01

    The Radiation Security System (RSS) at the Los Alamos Neutron Science Center (LANSCE) provides personnel protection from prompt radiation due to accelerated beam. Active instrumentation, such as the Beam Current Limiter, is a component of the RSS. The current limiter is designed to limit the average current in a beam line below a specific level, thus minimizing the maximum current available for a beam spill accident. The beam current limiter is a self-contained, electrically isolated toroidal beam transformer which continuously monitors beam current. It is designed as fail-safe instrumentation. The design philosophy, hardware design, operation, and limitations of the device are described

  11. Revision of Booster to Storage Ring Transport Line Design and Injection Scheme for Top-Up Operation at NSRRC

    CERN Document Server

    Wang, Min-Huey; Chen, Jenny; Chen June Rong; Hsu, Kuo-Tung; Kuo, Chin-Cheng; Luo, Gwo-Huei

    2005-01-01

    In order to help the operation of constant current, the optics of booster to storage ring transport line (BTS) design is reinvestigated. The initial twiss parameters are derived by measurement. The optics of the transport line is readjusted according to the measured initial beam parameters. The design of pulse width of the injection kicker is also changed from 1.2μsecond to 2.0μsecond. The injection scheme is reviewed and the effects of the kicker error on both injected beam and stored beam are investigated and shown in this report.

  12. Commissioning results of the ReA EBIT charge breeder at the NSCL: First reacceleration of stable-isotope beams

    Energy Technology Data Exchange (ETDEWEB)

    Lapierre, A., E-mail: lapierre@nscl.msu.edu; Schwarz, S.; Kittimanapun, K.; Rodriguez, J.A.; Sumithrarachchi, C.; Barquest, B.; Berryman, E.; Cooper, K.; Fogleman, J.; Krause, S.; Kwarsick, J.; Nash, S.; Perdikakis, G.; Portillo, M.; Rencsok, R.; Skutt, D.; Steiner, M.; Tobos, L.; Wittmer, W.; Bollen, G.; and others

    2013-12-15

    Highlights: • Latest results with the electron-beam ion trap of the ReA post-accelerator at the NSCL. • First reacceleration of stable-isotope beams. • First injection of stable-isotope beams from the NSCL’s beam stopping vault. -- Abstract: ReA is a reaccelerator of rare-isotope beams at the National Superconducting Cyclotron Laboratory (NSCL). The rare isotopes are produced by fast projectile fragmentation. After production, they are separated in-flight and thermalized in a He gas “catcher” cell before being sent to ReA for reacceleration to a few MeV/u. One of its main components is an electron-beam ion trap (EBIT) employed to convert injected singly charged ions to highly charged ions prior to injection into linear-accelerator structures. The ReA EBIT features a high-current electron gun, a long trap structure, and a two-field superconducting magnet to provide both the high electron-beam current density needed for fast charge breeding and high capture probability of injected beams. This paper presents recent commissioning results. In particular, {sup 39}K{sup +} ions have been injected, charge bred to {sup 39}K{sup 16+} and extracted for reacceleration up to 60 MeV. First charge-breeding results of beams injected from a commissioning Rb ion source in the NSCL’s beam “stopping” vault are also presented.

  13. The beam dump tunnels

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    In these images workers are digging the tunnels that will be used to dump the counter-circulating beams. Travelling just a fraction under the speed of light, the beams at the LHC will each carry the energy of an aircraft carrier travelling at 12 knots. In order to dispose of these beams safely, a beam dump is used to extract the beam and diffuse it before it collides with a radiation shielded graphite target.

  14. Ion beam diagnosis

    International Nuclear Information System (INIS)

    Strehl, P.

    1994-04-01

    This report is an introduction to ion beam diagnosis. After a short description of the most important ion beam parameters measurements of the beam current by means of Faraday cups, calorimetry, and beam current transformers and measurements of the beam profile by means of viewing screens, profile grids and scanning devices, and residual gas ionization monitors are described. Finally measurements in the transverse and longitudinal phase space are considered. (HSI)

  15. The 12-GeV/c beam transfer and absorber lines for the Superconducting Super Collider

    International Nuclear Information System (INIS)

    Mao, N.; McGill, J.; Gerig, R.; Brown, K.

    1994-08-01

    The beam optics of the 12-GeV/c proton beam transfer line between the Low Energy Booster (LEB) and the Medium Energy Booster (MEB) at the Superconducting Super Collider is presented. The beam is extracted from the LEB vertically and is injected into the MEB through a vertical Lambertson magnet and a horizontal kicker. The beamline has high flexibility for amplitude and dispersion function matching. Effects of various errors in the transfer line are studied, and a beam position correction scheme is proposed. The beam optics of the 12-GeV/c absorber line transporting the beam from the LEB to an absorber during the LEB commissioning is also presented

  16. Water injection dredging

    NARCIS (Netherlands)

    Verhagen, H.J.

    2000-01-01

    Some twenty years ago WIS-dredging has been developed in the Netherlands. By injecting water into the mud layer, the water content of the mud becomes higher, it becomes fluid mud and will start to flow. The advantages of this system are that there is no need of transporting the mud in a hopper, and

  17. Arsenic Trioxide Injection

    Science.gov (United States)

    Arsenic trioxide comes as a solution (liquid) to be injected into a vein by a doctor or nurse in a medical office or clinic. Arsenic trioxide is ... high blood sugar): extreme thirst frequent urination extreme hunger weakness blurred vision If high blood sugar is ...

  18. Meropenem and Vaborbactam Injection

    Science.gov (United States)

    ... Vaborbactam is in a class of medications called beta-lactamase inhibitors. It works by preventing bacteria from destroying meropenem.Antibiotics such as meropenem and vaborbactam injection will not ... your risk of getting an infection later that resists antibiotic treatment.

  19. SPS injection kicker magnet

    CERN Document Server

    1975-01-01

    One of the first-generation SPS injection kicker magnets. Lifting the tank-lid reveals the inner structure. For a more detailed description see 7502072X. See also 7502074X and Annual Report 1975, p.162. To the left: Roland Tröhler; to the right: Giacomo Busetta.

  20. Iron Sucrose Injection

    Science.gov (United States)

    ... severe or do not go away: constipation arm, leg, or back pain muscle cramps loss of energy changes in taste ear pain fever pain, redness, or swelling in the joints, especially the big toe soreness, redness, or burning at the injection ...

  1. More than just someone to inject drugs with: Injecting within primary injection partnerships.

    Science.gov (United States)

    Morris, Meghan D; Bates, Anna; Andrew, Erin; Hahn, Judith; Page, Kimberly; Maher, Lisa

    2015-11-01

    Studies have shown intimate injection partners engage in higher rates of syringe and injecting equipment sharing. We examined the drug use context and development of injection drug use behaviors within intimate injection partnerships. In-depth interviews (n=18) were conducted with both members of nine injecting partnerships in Sydney, Australia. Content analysis identified key domains related to the reasons for injecting with a primary injection partner and development of drug injection patterns. Most partnerships (n=5) were also sexual; three were blood-relatives and one a friend dyad. The main drug injected was heroin (66%) with high rates of recent sharing behaviors (88%) reported within dyads. Injecting within a primary injection partnership provided perceived protection against overdose events, helped reduce stress, increased control over when, where, and how drugs were used, and promoted the development of an injecting pattern where responsibilities could be shared. Unique to injecting within primary injection partnerships was the social connection and companionship resulted in a feeling of fulfillment while also blinding one from recognizing risky behavior. Findings illuminated the tension between protection and risks within primary injection partnerships. Primary injection partnerships provide a potential platform to expand risk reduction strategies. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  2. A Neutral Beam Injector Upgrade for NSTX

    International Nuclear Information System (INIS)

    Stevenson, T.; McCormack, B.; Loesser, G.D.; Kalish, M.; Ramakrishnan, S.; Grisham, L.; Edwards, J.; Cropper, M.; Rossi, G.; Halle, A. von; Williams, M.

    2002-01-01

    The National Spherical Torus Experiment (NSTX) capability with a Neutral Beam Injector (NBI) capable of 80 kiloelectronvolt (keV), 5 Megawatt (MW), 5 second operation. This 5.95 million dollar upgrade reused a previous generation injector and equipment for technical, cost, and schedule reasons to obtain these specifications while retaining a legacy capability of 120 keV neutral particle beam delivery for shorter pulse lengths for possible future NSTX experiments. Concerns with NBI injection included power deposition in the plasma, aiming angles from the fixed NBI fan array, density profiles and beam shine through, orbit losses of beam particles, and protection of the vacuum vessel wall against beam impingement. The upgrade made use of the beamline and cryo panels from the Neutral Beam Test Stand facility, existing power supplies and controls, beamline components and equipment not contaminated by tritium during DT [deuterium-tritium] experiments, and a liquid Helium refrigerator plant to power and cryogenically pump a beamline and three ion sources. All of the Tokamak Fusion Test Reactor (TFTR) ion sources had been contaminated with tritium, so a refurbishment effort was undertaken on selected TFTR sources to rid the three sources destined for the NSTX NBI of as much tritium as possible. An interconnecting duct was fabricated using some spare and some new components to attach the beamline to the NSTX vacuum vessel. Internal vacuum vessel armor using carbon tiles was added to protect the stainless steel vacuum vessel from beam impingement in the absence of plasma and interlock failure. To date, the NBI has operated to 80 keV and 5 MW and has injected requested power levels into NSTX plasmas with good initial results, including high beta and strong heating characteristics at full rated plasma current

  3. First experiences of beam presence detection based on dedicated beam position monitors

    International Nuclear Information System (INIS)

    Jalal, A.; Gabourin, S.; Gasior, M.; Todd, B.

    2012-01-01

    High intensity particle beam injection into the LHC is only permitted when a low intensity pilot beam is already circulating in the LHC. This requirement addresses some of the risks associated with high intensity injection, and is enforced by a so-called Beam Presence Flag (BPF) system which is part of the interlock chain between the LHC and its injector complex. For the 2010 LHC run, the detection of the presence of this pilot beam was implemented using the LHC Fast Beam Current Transformer (FBCT) system. However, the primary function of the FBCTs, that is reliable measurement of beam currents, did not allow the BPF system to satisfy all quality requirements of the LHC Machine Protection System (MPS). Safety requirements associated with high intensity injections triggered the development of a dedicated system, based on Beam Position Monitors (BPM). This system was meant to work first in parallel with the FBCT BPF system and eventually replace it. At the end of 2010 and in 2011, this new BPF implementation based on BPMs was designed, built, tested and deployed. This paper reviews both the FBCT and BPM implementation of the BPF system, outlining the changes during the transition period. The paper briefly describes the testing methods, focuses on the results obtained from the tests performed during the end of 2010 LHC run and shows the changes made for the BPM BPF system deployment in LHC in 2011. Whilst the system has been proved to work with a threshold of 6*10 8 charges, it has been implemented with a threshold of 2*10 9 charges to protect the LHC. (authors)

  4. Radiotracer injections through microfilters

    International Nuclear Information System (INIS)

    Huber, H.; Maschek, G.; Pichler, R.; Giesen, I.; Hatzl-Griesenhofer, M.; Maschek, W.

    2002-01-01

    Full text: Problems with the injection of radiotracers ( 99m Tc-HAMS, 99m Tc-DPD) to infants when administered through polar-filter-protected venous pathways caused us to get a closer look of what happens to a tracer in such a system. We simulated injections of the tracers mainly used at our institution in an in-vitro array and measured full and empty tracer syringes, filters (0.2 μm micropores) and the post-filter receptacle of the radioactivity. We calculated the percentage of filter-trapped activity and of activity in the receptacle. For several tracers we repeated this process with a neutral filter of the same pore size to get a comparison between the behavior in polarized and electrically inert filters. In general injection of a soluble radiotracer through a polar filter system means a dose loss in the filter of about 10 %, up to the tracer molecule size of IgG-antibodies. Suspended tracers, which consist of comparatively large particles, like RES- or pulmonary perfusion markers, are blocked by the filter, as can be foreseen with a particle size of >> 0.2 μm. DMSA and DPD (a biphosphonate), although both being soluble and rather small molecules, were blocked by the polar filter to a high extent, and by the neutral filter to a much lower, almost neglectable degree. The conclusions are: if possible avoid any use of a filter in your tracer injection pathway. Never use a filter with bone scan or DMSA applications. When doing uptake calculations you have to add the filter counts to the empty syringe value in the formula. If you cannot avoid to inject the radiotracer through a filter you have to replace the filter afterwards and treat the used filter as radioactive waste. The polarity of the filter material might severely affect retention of radiotracer in the filter. (author)

  5. Conceptual MEIC electron ring injection scheme using CEBAF as a full energy injector

    International Nuclear Information System (INIS)

    The Medium-energy Electron-Ion Collider (MEIC) proposed by Jefferson Lab is planning to use the newly upgraded 12 GeV CEBAF 1497 MHz SRF CW recirculating linac as a full-energy injector for the electron collider ring. The electron collider ring is proposed to reuse the 476 MHz PEP-II RF system to achieve high installed voltage and high beam power. The MEIC electron injection requires 3-10 (or 12) GeV beam in 3-4µs long bunch trains with low duty factor and high peak current, resulting in strong transient beam loading for the CEBAF. In this paper, we propose an injection scheme that can match the two systems' frequencies with acceptable injection time, and also address the transient beam loading issue in CEBAF. The scheme is compatible with future upgrade to 952.6 MHz SRF system in the electron ring.

  6. Design of the Injection and extraction system and related machine protection for the Clic Damping Rings

    CERN Document Server

    Apsimon, Robert; Barnes, Mike; Borburgh, Jan; Goddard, Brennan; Papaphilippou, Yannis; Uythoven, Jan

    2014-01-01

    Linear machines such as CLIC have relatively low rates of collision between bunches compared to their circular counterparts. In order to achieve the required luminosity, a very small spot size is envisaged at the interaction point, thus a low emittance beam is needed. Damping rings are essential for producing the low emittances needed for the CLIC main beam. It is crucial that the beams are injected and extracted from the damping rings in a stable and repeatable fashion to minimise emittance blow-up and beam jitter at the interaction point; both of these effects will deteriorate the luminosity at the interaction point. In this paper, the parameters and constraints of the injection and extraction systems are considered and the design of these systems is optimised within this parameter space. Related machine protection is considered in order to prevent damage from potential failure modes of the injection and extraction systems.

  7. New injection scheme using a pulsed quadrupole magnet in electron storage rings

    Directory of Open Access Journals (Sweden)

    Kentaro Harada

    2007-12-01

    Full Text Available We demonstrated a new injection scheme using a single pulsed quadrupole magnet (PQM with no pulsed local bump at the Photon Factory Advanced Ring (PF-AR in High Energy Accelerator Research Organization (KEK. The scheme employs the basic property of a quadrupole magnet, that the field at the center is zero, and nonzero elsewhere. The amplitude of coherent betatron oscillation of the injected beam is effectively reduced by the PQM; then, the injected beam is captured into the ring without largely affecting the already stored beam. In order to investigate the performance of the scheme with a real beam, we built the PQM providing a higher field gradient over 3  T/m and a shorter pulse width of 2.4  μs, which is twice the revolution period of the PF-AR. After the field measurements confirmed the PQM specifications, we installed it into the ring. Then, we conducted the experiment using a real beam and consequently succeeded in storing the beam current of more than 60 mA at the PF-AR. This is the first successful beam injection using a single PQM in electron storage rings.

  8. Direct observation of beam bunching in BWO experiments

    CERN Document Server

    Morimoto, I; Maebara, S; Kishiro, J; Takayama, K; Horioka, K; Ishizuka, H; Kawasaki, S; Shiho, M

    2001-01-01

    Backward Wave Oscillation (BWO) experiments using a Large current Accelerator-1 (Lax-1) Induction Linac as a seed power source for an mm-wave FEL are under way. The Lax-1 is typically operated with a 1 MeV electron beam, a few kA of beam current, and a pulse length of 100 ns. In the BWO experiments, annular and solid beams are injected into a corrugated wave guide with guiding axial magnetic field of 1 T. In the BWO with annular beam an output power of 210 MW at 9.8 GHz was obtained. With a solid beam the output power was 130 MW, and an electron beam bunching with the frequency of 9.6-10.2 GHz was observed by a streak camera.

  9. Nonlinear wave-beam kinetic equilibrium in decelerating systems

    International Nuclear Information System (INIS)

    Grishin, V.K.; Shaposhnikova, E.N.

    1981-01-01

    The equilibrium state of the wave-beam system arising during the interaction of a particle beam and excited electromagnetic wave has been investigated on the basis of the analysis of the exact polution of a non-linear self-consistent linear equation using the complete system of conservation laws. A waveguide with a dielectric filler, into which a monoenergetic particle beam magnetized in a transverse plane is continuously injected, is used as a model of an decelerating system. A dispersion equation describing the system state and expression for the evaluation of efficiency of the beam energy conversion to the field energy have been obtained. It is concluded that larae fields and high efficiency of energy conversion are achieved during the marked beam reconstruction. States with different values of current and beam velocity but similar amplitudes of a longitudinal field are possible in the system considered [ru

  10. Measurements on wave propagation characteristics of spiraling electron beams

    Science.gov (United States)

    Singh, A.; Getty, W. D.

    1976-01-01

    Dispersion characteristics of cyclotron-harmonic waves propagating on a neutralized spiraling electron beam immersed in a uniform axial magnetic field are studied experimentally. The experimental setup consisted of a vacuum system, an electron-gun corkscrew assembly which produces a 110-eV beam with the desired delta-function velocity distribution, a measurement region where a microwave signal is injected onto the beam to measure wavelengths, and a velocity analyzer for measuring the axial electron velocity. Results of wavelength measurements made at beam currents of 0.15, 1.0, and 2.0 mA are compared with calculated values, and undesirable effects produced by increasing the beam current are discussed. It is concluded that a suitable electron beam for studies of cyclotron-harmonic waves can be generated by the corkscrew device.

  11. Beam diagnostics for low energy beams

    Directory of Open Access Journals (Sweden)

    J. Harasimowicz

    2012-12-01

    Full Text Available Low-energetic ion and antimatter beams are very attractive for a number of fundamental studies. The diagnostics of such beams, however, is a challenge due to low currents down to only a few thousands of particles per second and significant fraction of energy loss in matter at keV beam energies. A modular set of particle detectors has been developed to suit the particular beam diagnostic needs of the ultralow-energy storage ring (USR at the future facility for low-energy antiproton and ion research, accommodating very low beam intensities at energies down to 20 keV. The detectors include beam-profile monitors based on scintillating screens and secondary electron emission, sensitive Faraday cups for absolute intensity measurements, and capacitive pickups for beam position monitoring. In this paper, the design of all detectors is presented in detail and results from beam measurements are shown. The resolution limits of all detectors are described and options for further improvement summarized. Whilst initially developed for the USR, the instrumentation described in this paper is also well suited for use in other low-intensity, low-energy accelerators, storage rings, and beam lines.

  12. Performance of the PDX neutral beam wall armor

    International Nuclear Information System (INIS)

    Kugel, H.W.; Eubank, H.P.; Kozub, T.A.; Williams, M.D.

    1985-02-01

    The PDX wall armor was designed to function as an inner wall thermal armor, a neutral beam diagnostic, and a large area inner toroidal plasma limiter. In this paper we discuss its thermal performance as wall armor during two years of PDX neutral beam heating experiments. During this period it provided sufficient inner wall protection to permit perpendicular heating injections into normal and disruptive plasmas as well as injections in the absence of plasma involving special experiments, calibrations, and tests important for the optimization and development of the PDX neutral beam injection system. Many of the design constraints and performance issues encountered in this work are relevant to the design of larger fusion devices

  13. Absolute luminosity measurement at LHCb with beam-gas imaging

    CERN Document Server

    Barschel, C

    2013-01-01

    A novel technique to measure the absolute luminosity at the Large Hadron Collider (LHC) using beam-gas interactions has been successfully used in the LHCb experiment. A gas injection device (SMOG) has been installed in the LHCb experiment to increase the pressure around the interaction point during dedicated fills. The Beam-Gas Imaging method (BGI) has now the potential to surpass the accuracy of the commonly used *van der Meer scan* method (VDM). The technique has been used in 10 LHC fills during 2012 including and also provided a first luminosity measurement for proton-lead collisions. This talk presents the principles of the gas injection and the improvements reached with the increased pressure. Furthermore the gas injection increased the accuracy measurement of the so-called ghost charges and also intensities per bunch. Those uncertainties are becoming the dominating factor because the uncertainty on the total beam current have been reduced.

  14. Fusion Energy Division automation of the ISX-B neutral beams

    International Nuclear Information System (INIS)

    Bates, S.C.; Hanna, P.C.

    1982-06-01

    Operation of the two neutral beams on the ISX-B tokamak has been fully automated for an injected power up to 2 MW. A PDP 11/34 FORTRAN program conditions and injects the beams using commercial CAMAC hardware and ad hoc modifications of the beam controls. The fundamental beam conditioning algorithm is based on the breakdown history of the source. Difficulties encountered were noise entering the CAMAC system through control and data lines and the lack of well-defined operating heuristics detailed problem diagnostic techniques. A brief description is given of the hardware and software systems, operating techniques, and items of special concern

  15. LHCb: A novel method for an absolute luminosity measurement at LHCb using beam-gas imaging

    CERN Multimedia

    Barschel, C

    2013-01-01

    A novel technique to measure the absolute luminosity at the Large Hadron Collider (LHC) using beam-gas interactions has been successfully used in the LHCb experiment. A gas injection device (SMOG) has been installed in the LHCb experiment to increase the pressure around the interaction point during dedicated fills. The Beam Gas Imaging method (BGI) has now the potential to surpass the accuracy of the commonly used van der Meer scan method (VDM). This poster presents the principles of the Beam Gas Imaging method used to measure the beam overlap integral. Furthermore the gas injection increased the accuracy measurement of the so-called ghost charges and also intensities per bunch.

  16. Revisit of combined parallel-beam/cone-beam or fan-beam/cone-beam imaging.

    Science.gov (United States)

    Zeng, Gengsheng L

    2013-10-01

    This aim of this paper is to revisit the parallel-beam/cone-beam or fan-beam/cone-beam imaging configuration, and to investigate whether this configuration has any advantages. Twenty years ago, it was suggested to simultaneously use a parallel-beam (or a fan-beam) collimator and a cone-beam collimator to acquire single photon emission computed tomography data. The motivation was that the parallel-beam (or the fan-beam) collimator can provide sufficient sampling, while the cone-beam collimator is able to provide higher photon counts. Even with higher total counts, this hybrid system does not give significant improvement (if any) in terms of image noise and artifacts reduction. If a conventional iterative maximum-likelihood expectation-maximization algorithm is used to reconstruct the image, the resultant reconstruction may be worse than the parallel-beam-only (or fan-beam-only) system. This paper uses the singular value decomposition (SVD) analysis to explain this phenomenon. The SVD results indicate that the parallel-beam-only and the fan-beam-only system outperform the combined systems. The optimal imaging system does not necessary to be the one that generates the projections with highest signal-to-noise ratio and best resolution.

  17. Investigations on transport and storage of high ion beam intensities

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, Ninad Shrikrishna

    2009-08-25

    In the framework of this thesis the intense low energy ion beam transport was investigated. Especially, the beam transport in toroidal magnetic field configurations was discussed, as it may allow the accumulation of high intensive beams in the future. One of the specific tasks is to design an injection system that can be used for the proposed low energy accumulator ring. A simulation code (TBT) was written to describe the particle motion in curved segments. Particle in Cell techniques were utilized to simulate a multi particle dynamics. A possibility of reading an external data file was made available so that a measured distribution can be used to compare simulation results with measured ones. A second order cloud in cell method was used to calculate charge density and in turn to solve Poisson's equation. Further simulations were performed to study the self field effects on beam transport. Experiments were performed to compare the simulation results and gain practical experience. The preparatory experiments consisted of building and characterization of the ion source in a first step. Along with the momentum spectrometer and emittance scanner the beam properties were studied. Low mass ion beams He{sup +} and mixed p, H{sup 2+}, H{sup 3+} beams were analyzed. In the second stage, beams were transported through a solenoid and the phase space distribution was measured as a function of the magnetic field for different beam energies. The phase-space as distributions measured in a first stage were simulated backward and then again forward transported through the solenoid. The simulated results were then compared with the measured distribution. The LINTRA transport program was used. The phase-space distribution was further simulated for transport experiments in a toroidal magnetic field. The transport program that was used to simulate the beam in the toroid was also used to design the injection system. The injection system with its special field configurations was

  18. Investigations on transport and storage of high ion beam intensities

    International Nuclear Information System (INIS)

    Joshi, Ninad Shrikrishna

    2009-01-01

    In the framework of this thesis the intense low energy ion beam transport was investigated. Especially, the beam transport in toroidal magnetic field configurations was discussed, as it may allow the accumulation of high intensive beams in the future. One of the specific tasks is to design an injection system that can be used for the proposed low energy accumulator ring. A simulation code (TBT) was written to describe the particle motion in curved segments. Particle in Cell techniques were utilized to simulate a multi particle dynamics. A possibility of reading an external data file was made available so that a measured distribution can be used to compare simulation results with measured ones. A second order cloud in cell method was used to calculate charge density and in turn to solve Poisson's equation. Further simulations were performed to study the self field effects on beam transport. Experiments were performed to compare the simulation results and gain practical experience. The preparatory experiments consisted of building and characterization of the ion source in a first step. Along with the momentum spectrometer and emittance scanner the beam properties were studied. Low mass ion beams He + and mixed p, H 2+ , H 3+ beams were analyzed. In the second stage, beams were transported through a solenoid and the phase space distribution was measured as a function of the magnetic field for different beam energies. The phase-space as distributions measured in a first stage were simulated backward and then again forward transported through the solenoid. The simulated results were then compared with the measured distribution. The LINTRA transport program was used. The phase-space distribution was further simulated for transport experiments in a toroidal magnetic field. The transport program that was used to simulate the beam in the toroid was also used to design the injection system. The injection system with its special field configurations was designed to perform

  19. Low current beam techniques

    Energy Technology Data Exchange (ETDEWEB)

    Saint, A.; Laird, J.S.; Bardos, R.A.; Legge, G.J.F. [Melbourne Univ., Parkville, VIC (Australia). School of Physics; Nishijima, T.; Sekiguchi, H. [Electrotechnical Laboratory, Tsukuba (Japan).

    1993-12-31

    Since the development of Scanning Transmission Microscopy (STIM) imaging in 1983 many low current beam techniques have been developed for the scanning (ion) microprobe. These include STIM tomography, Ion Beam Induced Current, Ion Beam Micromachining and Microlithography and Ionoluminense. Most of these techniques utilise beam currents of 10{sup -15} A down to single ions controlled by beam switching techniques This paper will discuss some of the low beam current techniques mentioned above, and indicate, some of their recent applications at MARC. A new STIM technique will be introduced that can be used to obtain Z-contrast with STIM resolution. 4 refs., 3 figs.

  20. Beam position measurement system at the Fermilab main accelerator

    International Nuclear Information System (INIS)

    Kerns, Q.A.

    1975-01-01

    The beam position system of the Fermilab Main Ring contains one horizontal and one vertical Electrostatic Beam Pickup in each of the 96 cells of the machine. A pair of 75 ohm cables transmits the induced signal from the machine tunnel to the nearest service building. In each of the 24 service buildings, there is a solid-state multiplexer and a beam position detector which processes the A-B signal pairs to produce an intensity-normalized voltage proportional to beam displacement. This voltage is digitized, read into buffer of the Lockheed MAC A, and in turn transferred to the Xerox 530. Horizontal or vertical orbits can be obtained in 50 millisec. Orbits are obtained at injection and at a Main Ring Sample time, if requested, anywhere on the acceleration cycle. Injection orbits can be flattened automatically by a program that sets dipole trim magnets. (auth)