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Sample records for superconducting linac scl

  1. Superconducting Hadron Linacs

    CERN Document Server

    Ostroumov, Peter

    2013-01-01

    This article discusses the main building blocks of a superconducting (SC) linac, the choice of SC resonators, their frequencies, accelerating gradients and apertures, focusing structures, practical aspects of cryomodule design, and concepts to minimize the heat load into the cryogenic system. It starts with an overview of design concepts for all types of hadron linacs differentiated by duty cycle (pulsed or continuous wave) or by the type of ion species (protons, H-, and ions) being accelerated. Design concepts are detailed for SC linacs in application to both light ion (proton, deuteron) and heavy ion linacs. The physics design of SC linacs, including transverse and longitudinal lattice designs, matching between different accelerating–focusing lattices, and transition from NC to SC sections, is detailed. Design of high-intensity SC linacs for light ions, methods for the reduction of beam losses, preventing beam halo formation, and the effect of HOMs and errors on beam quality are discussed. Examples are ta...

  2. Superconducting energy recovery linacs

    Science.gov (United States)

    Ben-Zvi, Ilan

    2016-10-01

    High-average-power and high-brightness electron beams from a combination of laser photocathode electron guns and a superconducting energy recovery linac (ERL) is an emerging accelerator science with applications in ERL light sources, high repetition rate free electron lasers , electron cooling, electron ion colliders and more. This paper reviews the accelerator physics issues of superconducting ERLs, discusses major subsystems and provides a few examples of superconducting ERLs.

  3. Superconducting LINAC booster for the Mumbai pelletron

    Indian Academy of Sciences (India)

    B Srinivasan; S K Singh; R G Pillay; M P Kurup; M K Pandey

    2001-08-01

    We are in the process of constructing a superconducting linear accelerator (LINAC), to boost the energy of heavy ion beams from the 14UD Pelletron accelerator, at Tata Institute of Fundamental Research, Mumbai. The accelerating structures in the LINAC are quarter wave resonators (QWR) coated with lead which is superconducting at liquid helium temperature. With feasibility studies having been completed during the course of the 4th and 5th five-year plan periods, culminating with the demonstration of beam acceleration using one accelerating module, the construction of the LINAC is now under way.

  4. Study on design of superconducting proton linac for accelerator driven subcritical nuclear power system

    CERN Document Server

    Yu Qi; Xu Tao Guang

    2002-01-01

    As a prior option of the next generation of energy source, the accelerator driven subcritical nuclear power system (ADS) can use efficiently the uranium and thorium resource, transmute the high-level long-lived radioactive wastes and raise nuclear safety. The ADS accelerator should provide the proton beam with tens megawatts. The superconducting linac (SCL) is a good selection of ADS accelerator because of its high efficiency and low beam loss rate. It is constitute by a series of the superconducting accelerating cavities. The cavity geometry is determined by means of the electromagnetic field computation. The SCL main parameters are determined by the particle dynamics computation

  5. Argonne superconducting heavy-ion linac

    Energy Technology Data Exchange (ETDEWEB)

    Bollinger, L.M.; Benaroya, R.; Clifft, B.E.; Jaffey, A.H.; Johnson, K.W.; Khoe, T.K.; Scheibelhut, C.H.; Shepard, K.W.; Wangler, Y.Z.

    1976-01-01

    A summary is given of the status of a project to develop and build a small superconducting linac to boost the energy of heavy ions from an existing tandem electrostatic accelerator. The design of the system is well advanced, and construction of major components is expected to start in late 1976. The linac will consist of independently-phased resonators of the split-ring type made of niobium and operating at a temperature of 4.2/sup 0/K. The resonance frequency is 97 MHz. Tests on full-scale resonators lead one to expect accelerating fields of approximately 4 MV/m within the resonators. The linac will be long enough to provide a voltage gain of at least 13.5 MV, which will allow ions with A less than or approximately 80 to be accelerated above the Coulomb barrier of any target. The modular nature of the system will make future additions to the length relatively easy. A major design objective is to preserve the good quality of the tandem beam. This requires an exceedingly narrow beam pulse, which is achieved by bunching both before and after the tandem. Focusing by means of superconducting solenoids within the linac limit the radial size of the beam. An accelerating structure some 15 meters downstream from the linac will manipulate the longitudinal phase ellipse so as to provide the experimenter with either very good energy resolution (..delta..E/E approximately equal to 2 x 10/sup -4/) or very good time resolution (..delta.. t approximately equal to 30 psec).

  6. Beam commissioning for a superconducting proton linac

    Science.gov (United States)

    Wang, Zhi-Jun; He, Yuan; Jia, Huan; Dou, Wei-ping; Chen, Wei-long; Zhang, X. L.; Liu, Shu-hui; Feng, Chi; Tao, Yue; Wang, Wang-sheng; Wu, Jian-qiang; Zhang, Sheng-hu; Zhao, Hong-Wei

    2016-12-01

    To develop the next generation of safe and cleaner nuclear energy, the accelerator-driven subcritical (ADS) system emerges as one of the most attractive technologies. It will be able to transmute the long-lived transuranic radionuclides produced in the reactors of today's nuclear power plants into shorter-lived ones, and also it will provide positive energy output at the same time. The prototype of the Chinese ADS (C-ADS) proton accelerator comprises two injectors and a 1.5 GeV, 10 mA continuous wave (CW) superconducting main linac. The injector scheme II at the C-ADS demo facility inside the Institute of Modern Physics is a 10 MeV CW superconducting linac with a designed beam current of 10 mA, which includes an ECR ion source, a low-energy beam transport line, a 162.5 MHz radio frequency quadrupole accelerator, a medium-energy beam transport line, and a superconducting half wave resonator accelerator section. This demo facility has been successfully operating with an 11 mA, 2.7 MeV CW beam and a 3.9 mA, 4.3 MeV CW beam at different times and conditions since June 2014. The beam power has reached 28 kW, which is the highest record for the same type of linear accelerators. In this paper, the parameters of the test injector II and the progress of the beam commissioning are reported.

  7. Commercial Superconducting Electron Linac for Radioisotope Production

    Energy Technology Data Exchange (ETDEWEB)

    Grimm, Terry Lee [Niowave, Inc., Lansing, MI (United States); Boulware, Charles H. [Niowave, Inc., Lansing, MI (United States); Hollister, Jerry L. [Niowave, Inc., Lansing, MI (United States); Jecks, Randall W. [Niowave, Inc., Lansing, MI (United States); Mamtimin, Mayir [Niowave, Inc., Lansing, MI (United States); Starovoitova, Valeriia [Niowave, Inc., Lansing, MI (United States)

    2015-08-13

    The majority of radioisotopes used in the United States today come from foreign suppliers or are generated parasitically in large government accelerators and nuclear reactors. Both of these restrictions limit the availability of radioisotopes and discourage the development and evaluation of new isotopes and for nuclear medicine, science, and industry. Numerous studies have been recommending development of dedicated accelerators for production of radioisotopes for over 20 years (Institute of Medicine, 1995; Reba, et al, 2000; National Research Council, 2007; NSAC 2009). The 2015 NSAC Long Range Plan for Isotopes again identified electron accelerators as an area for continued research and development. Recommendation 1(c) from the 2015 NSAC Isotope report specifically identifies electron accelerators for continued funding for the purpose of producing medical and industrial radioisotopes. Recognizing the pressing need for new production methods of radioisotopes, the United States Congress passed the American Medical Isotope Production Act of 2012 to develop a domestic production of 99Mo and to eliminate the use of highly enriched uranium (HEU) in the production of 99Mo. One of the advantages of high power electron linear accelerators (linacs) is they can create both proton- and neutron-rich isotopes by generating high energy x-rays that knock out protons or neutrons from stable atoms or by fission of uranium. This allows for production of isotopes not possible in nuclear reactors. Recent advances in superconducting electron linacs have decreased the size and complexity of these systems such that they are economically competitive with nuclear reactors and large, high energy accelerators. Niowave, Inc. has been developing a radioisotope production facility based on a superconducting electron linac with liquid metal converters.

  8. HOM Dampers or not in Superconducting RF Proton Linacs

    CERN Document Server

    Tückmantel, Joachim

    2009-01-01

    Circular machines are plagued by Coupled Bunch Instabilities, driven by impedance peaks, irrespectively of their frequency relation to machine lines; hence all cavity Higher Order Modes are possible drivers. This is the fundamental reason that all superconducting RF cavities in circular machines are equipped with HOM dampers. This raises the question if HOM damping would not be imperative also in high current proton linacs where a mechanism akin to CBI might exist. To clarify this question we have simulated the longitudinal bunched beam dynamics in linacs, allowing bunch-to-bunch variations in time-of-arrival. Simulations were executed for a generic proton linac with properties close to SNS or the planned SPL at CERN. It was found that for monopole HOMs with high Qext large beam scatter or even beam loss cannot be excluded. Therefore omitting HOM dampers on superconducting RF cavities in high current proton linacs, even pulsed ones, is a very risky decision.

  9. Heavy-ion acceleration with a superconducting linac

    Energy Technology Data Exchange (ETDEWEB)

    Bollinger, L.M.

    1988-01-01

    This year, 1988, is the tenth anniversary of the first use of RF superconductivity to accelerate heavy ions. In June 1978, the first two superconducting resonators of the Argonne Tandem-Linac Accelerator System (ATLAS) were used to boost the energy of a /sup 19/F beam from the tandem, and by September 1978 a 5-resonator linac provided an /sup 16/O beam for a nuclear-physics experiment. Since then, the superconducting linac has grown steadily in size and capability until now there are 42 accelerating structures and 4 bunchers. Throughout this period, the system was used routinely for physics research, and by now the total time with beam on target is 35,000 hours. Lessons learned from this long running experience and some key technical developments that made it possible are reviewed in this paper. 19 refs., 3 figs., 2 tabs.

  10. Initial operation of the Argonne superconducting heavy-ion linac

    Energy Technology Data Exchange (ETDEWEB)

    Shepard, K. W.

    1979-01-01

    Initial operation and recent development of the Argonne superconducting heavy-ion linac are discussed. The linac has been developed in order to demonstrate a cost-effective means of extending the performance of electrostatic tandem accelerators. The results of beam acceleration tests which began in June 1978 are described. At present 7 of a planned array of 22 resonators are operating on-line, and the linac system provides an effective accelerating potential of 7.5 MV. Although some technical problems remain, the level of performance and reliability is sufficient that appreciable beam time is becoming available to users.

  11. Computation of Normal Conducting and Superconducting Linear Accelerator (LINAC) Availabilities

    Energy Technology Data Exchange (ETDEWEB)

    Haire, M.J.

    2000-07-11

    A brief study was conducted to roughly estimate the availability of a superconducting (SC) linear accelerator (LINAC) as compared to a normal conducting (NC) one. Potentially, SC radio frequency cavities have substantial reserve capability, which allows them to compensate for failed cavities, thus increasing the availability of the overall LINAC. In the initial SC design, there is a klystron and associated equipment (e.g., power supply) for every cavity of an SC LINAC. On the other hand, a single klystron may service eight cavities in the NC LINAC. This study modeled that portion of the Spallation Neutron Source LINAC (between 200 and 1,000 MeV) that is initially proposed for conversion from NC to SC technology. Equipment common to both designs was not evaluated. Tabular fault-tree calculations and computer-event-driven simulation (EDS) computer computations were performed. The estimated gain in availability when using the SC option ranges from 3 to 13% under certain equipment and conditions and spatial separation requirements. The availability of an NC LINAC is estimated to be 83%. Tabular fault-tree calculations and computer EDS modeling gave the same 83% answer to within one-tenth of a percent for the NC case. Tabular fault-tree calculations of the availability of the SC LINAC (where a klystron and associated equipment drive a single cavity) give 97%, whereas EDS computer calculations give 96%, a disagreement of only 1%. This result may be somewhat fortuitous because of limitations of tabular fault-tree calculations. For example, tabular fault-tree calculations can not handle spatial effects (separation distance between failures), equipment network configurations, and some failure combinations. EDS computer modeling of various equipment configurations were examined. When there is a klystron and associated equipment for every cavity and adjacent cavity, failure can be tolerated and the SC availability was estimated to be 96%. SC availability decreased as

  12. Status Report on the Installation of the Warm Sections for the Superconducting Linac at the SNS

    CERN Document Server

    Kersevan, Roberto; Campisi, Isidoro E; Crandall, John A; Douglas, Debra L; Hunter, Ted; Ladd, Peter; Luck, Chris; Morton, Robert C; Russell, Kathy S; Stout, Daniel

    2005-01-01

    The SNS superconducting linac (SCL) consists of 23 cryomodules (CMs), with possibly 9 additional CMs being added for future energy upgrade from 1 GeV to 1.3 GeV. A total of 32 warm sections separate the comparatively short CMs, and this allows a CM exchange within 48 hours, in order to meet demanding beam availability specifications. The 32 warm section chambers are installed between each pair of CMs, with each section containing a quadrupole doublet, beam diagnostics, and pumping. The chambers are approximately 1.6 m long, have one bellow installed at each end for alignment, and are pumped by one ion-pump. The preparation and installation of these chambers must be made under stringent clean and particulate-free conditions, in order to ensure that the performance of the SCL CMs is not compromised. This paper will discuss the development of the cleaning, preparation, and installation procedures that have been adopted for the warm sections, and the vacuum performance of this system.

  13. Optical emission spectroscopy of the Linac4 and superconducting proton Linac plasma generators

    Energy Technology Data Exchange (ETDEWEB)

    Lettry, J.; Kronberger, M.; Mahner, E.; Schmitzer, C.; Sanchez, J.; Scrivens, R.; Midttun, O.; O' Neil, M.; Pereira, H.; Paoluzzi, M. [European Organization for Nuclear Research, CERN, 1211 Geneva 23 (Switzerland); Fantz, U.; Wuenderlich, D. [Max-Planck-Institut fuer Plasmaphysik, IPP, 85748 Garching (Germany); Kalvas, T.; Koivisto, H.; Komppula, J.; Myllyperkioe, P.; Tarvainen, O. [Department of Physics, University of Jyvaeskylae, 40500 Jyvaeskylae (Finland)

    2012-02-15

    CERN's superconducting proton Linac (SPL) study investigates a 50 Hz high-energy, high-power Linac for H{sup -} ions. The SPL plasma generator is an evolution of the DESY ion source plasma generator currently operated at CERN's Linac4 test stand. The plasma generator is a step towards a particle source for the SPL, it is designed to handle 100 kW peak RF-power at a 6% duty factor. While the acquisition of an integrated hydrogen plasma optical spectrum is straightforward, the measurement of a time-resolved spectrum requires dedicated amplification schemes. The experimental setup for visible light based on photomultipliers and narrow bandwidth filters and the UV spectrometer setup are described. The H{sub {alpha}}, H{sub {beta}}, and H{sub {gamma}} Balmer line intensities, the Lyman band and alpha transition were measured. A parametric study of the optical emission from the Linac4 ion source and the SPL plasma generator as a function of RF-power and gas pressure is presented. The potential of optical emission spectrometry coupled to RF-power coupling measurements for on-line monitoring of short RF heated hydrogen plasma pulses is discussed.

  14. High duty factor plasma generator for CERN's Superconducting Proton Linac.

    Science.gov (United States)

    Lettry, J; Kronberger, M; Scrivens, R; Chaudet, E; Faircloth, D; Favre, G; Geisser, J-M; Küchler, D; Mathot, S; Midttun, O; Paoluzzi, M; Schmitzer, C; Steyaert, D

    2010-02-01

    CERN's Linac4 is a 160 MeV linear accelerator currently under construction. It will inject negatively charged hydrogen ions into CERN's PS-Booster. Its ion source is a noncesiated rf driven H(-) volume source directly inspired from the one of DESY and is aimed to deliver pulses of 80 mA of H(-) during 0.4 ms at a 2 Hz repetition rate. The Superconducting Proton Linac (SPL) project is part of the luminosity upgrade of the Large Hadron Collider. It consists of an extension of Linac4 up to 5 GeV and is foreseen to deliver protons to a future 50 GeV synchrotron (PS2). For the SPL high power option (HP-SPL), the ion source would deliver pulses of 80 mA of H(-) during 1.2 ms and operate at a 50 Hz repetition rate. This significant upgrade motivates the design of the new water cooled plasma generator presented in this paper. Its engineering is based on the results of a finite element thermal study of the Linac4 H(-) plasma generator that identified critical components and thermal barriers. A cooling system is proposed which achieves the required heat dissipation and maintains the original functionality. Materials with higher thermal conductivity are selected and, wherever possible, thermal barriers resulting from low pressure contacts are removed by brazing metals on insulators. The AlN plasma chamber cooling circuit is inspired from the approach chosen for the cesiated high duty factor rf H(-) source operating at SNS.

  15. Development of a very-low-velocity superconducting linac

    Energy Technology Data Exchange (ETDEWEB)

    Shepard, K.W.

    1987-01-01

    Four types of superconducting accelerator structures are being developed for use in a low velocity positive-ion injector linac for the ATLAS heavy-ion accelerator. Prototypes of the first two of these have been tested. The structures are all variants of a quarter-wave line terminated with a four-gap interdigital drift-tube array. The two structure types so far tested operate at 48.5 mHz and have an active length of 10 cm (for the particle velocity - .008c type) and 16.5 cm (for the velocity - .014c type). Effective accelerating fields of 10 MV/m have been achieved with the 10 cm structure, corresponding to an effective accelerating potential of 1 MV. The 16.5 cm structure has been operated at field levels of 6 MV/m, also giving an effective potential of 1 MV. Prototypes of the remaining two resonant geometries are under construction.

  16. High Power CW Superconducting Linacs for EURISOL and XADS

    CERN Document Server

    Biarrotte, J L

    2004-01-01

    A multi-MW superconducting proton linac is proposed as the baseline solution for the EURISOL and the XADS driver accelerators. In the EURISOL project, which studies the design of the next-generation European ISOL facility, it is used to produce both neutron-deficient and neutron-rich exotic nuclei far from the valley of stability. In the PDS-XADS project, which aims to the demonstration of the feasibility of an ADS system for nuclear waste transmutation, it is used to produce the neutron flux required by the associated sub-critical reactor. In this paper, we report the main results and conclusions reached within these preliminary design studies. A special emphasis is given on the on-going and future R&D to be done to accomplish the demonstration of the full technology.

  17. Status of the Superconducting Proton Linac (SPL) Cryo-Module

    CERN Document Server

    Parma, V; Capatina, O; Chambrillon, J; Montesinos, E; Schirm, K; Vande Craen, A; Vandoni, G; Van Weelderen, R

    2014-01-01

    The Superconducting Proton Linac (SPL) is an R&D effort conducted by CERN in partnership with other international laboratories, aimed at developing key technologies for the construction of a multi-megawatt proton linac based on state-of-the-art SRF technology. Such an accelerator could serve as a driver in new physics facilities for neutrinos and/or radioactive ion beams [1]. Amongst the main objectives of this effort, are the development of 704 MHz bulk niobium beta=1 elliptical cavities (operating at 2 K and providing an accelerating gradient of 25 MV/m) and the test of a string of cavities integrated in a machine-type cryo-module. In an initial phase, only four out of the eight cavities of the SPL cryo-module will be tested in a half-length cryo-module developed for this purpose, which nonetheless preserves the main features of the full size module. This paper presents the final design of the cryo-module and the status of the construction of the main cryostat parts. Preliminary plans for the assembly a...

  18. Status of the Argonne superconducting-linac heavy-ion energy booster

    Energy Technology Data Exchange (ETDEWEB)

    Aron, J.; Benaroya, R.; Bollinger, L.M.; Clifft, B.E.; Henning, W.; Johnson, K.W.; Nixon, J.M.; Markovich, P.; Shepard, K.W.

    1979-01-01

    A superconducting linac is being constructed to provide an energy booster for heavy ions from an FN tandem. By late 1980 the linac will consist of 24 independently-phased superconducting resonators, and will provide an effective accelerating potential of more than 25 MV. While the linac is under construction, completed sections are being used to provide useful beam for nuclear physics experiments. In the most recent run with beam (June 1979), an eight resonator array provided an effective accelerating potential of 9.3 MV. Operation of a 12 resonator array is scheduled to begin in October 1979.

  19. Superconducting resonator used as a phase and energy detector for linac setup

    Science.gov (United States)

    Lobanov, Nikolai R.

    2016-07-01

    Booster linacs for tandem accelerators and positive ion superconducting injectors have matured into standard features of many accelerator laboratories. Both types of linac are formed as an array of independently-phased resonators operating at room temperature or in a superconducting state. Each accelerating resonator needs to be individually set in phase and amplitude for optimum acceleration efficiency. The modularity of the linac allows the velocity profile along the structure to be tailored to accommodate a wide range charge to mass ratio. The linac setup procedure, described in this paper, utilizes a superconducting resonator operating in a beam bunch phase detection mode. The main objective was to derive the full set of phase distributions for quick and efficient tuning of the entire accelerator. The phase detector was operated in overcoupling mode in order to minimize de-tuning effects of microphonic background. A mathematical expression was derived to set a limit on resonator maximum accelerating field during the crossover search to enable extracting unambiguous beam phase data. A set of equations was obtained to calculate the values of beam phase advance and energy gain produced by accelerating resonators. An extensive range of linac setting up configurations was conducted to validate experimental procedures and analytical models. The main application of a superconducting phase detector is for fast tuning for beams of ultralow intensities, in particular in the straight section of linac facilities.

  20. Comparison of coaxial higher order mode couplers for the CERN Superconducting Proton Linac study

    CERN Document Server

    AUTHOR|(CDS)2085329; Gerigk, Frank; Van Rienen, Ursula

    2017-01-01

    Higher order modes (HOMs) may affect beam stability and refrigeration requirements of superconducting proton linacs such as the Superconducting Proton Linac, which is studied at CERN. Under certain conditions beam-induced HOMs can accumulate sufficient energy to destabilize the beam or quench the superconducting cavities. In order to limit these effects, CERN considers the use of coaxial HOM couplers on the cutoff tubes of the 5-cell superconducting cavities. These couplers consist of resonant antennas shaped as loops or probes, which are designed to couple to potentially dangerous modes while sufficiently rejecting the fundamental mode. In this paper, the design process is presented and a comparison is made between various designs for the high-beta SPL cavities, which operate at 704.4 MHz. The rf and thermal behavior as well as mechanical aspects are discussed. In order to verify the designs, a rapid prototype for the favored coupler was fabricated and characterized on a low-power test-stand.

  1. Development of a superconducting LINAC booster for the Pelletron at Mumbai

    Indian Academy of Sciences (India)

    M B Kurup

    2002-11-01

    A superconducting linear accelerator (LINAC) to boost the energy of the heavy ion beams from the 14 UD pelletron accelerator at Mumbai is under development. The booster is based on quarter wave resonators (QWR) coated with lead which is superconducting at liquid helium temperature. The operating frequency is 150 MHz. Four resonators each are mounted in a cryostat module built indigenously. A total of seven such modules arranged in two arms with an isochronous and achromatic beam bend in the middle comprises the full LINAC. The transverse focusing of the beam through the LINAC is carried out using periodic quadrupole doublet magnets operating at room temperature. The present status of the project is described.

  2. Choice of Frequency, Gradient and Temperature for a Superconducting Proton Linac

    CERN Document Server

    Gerigk, F; Calatroni, S; Ciapala, Edmond; Eshraqi, M; Garoby, R; Lombardi, A M; Losito, R; Parma, V; Tückmantel, Joachim; Vretenar, M; Wagner, U; Weingarten, W

    2008-01-01

    The construction of a Superconducting Proton Linac is planned at CERN during the next decade. It is foreseen to be constructed in two stages: a low duty cycle, low-power linac (LPSPL) as an injector for a new 50 GeV synchrotron (PS2) replacing the present PS, which could be upgraded to a high-duty cycle, high-power linac (HPSPL), for the needs of future facility(ies) requiring a multi-MW beam power. In this paper we present the criteria which were used to choose the frequency, gradient, and cryogenic temperature of the SPL. Since these questions are common to other proposed high-power proton linacs, they may also be of use for other projects with similar specifications. The various design options are discussed as well as their impact on beam dynamics, cavity performance, power consumption, cryogenics,and overall efficiency.

  3. Calculation of acceptance of high intensity superconducting proton linac for Project X

    CERN Document Server

    Saini, A; Solyak, N; Mishra, S; Yakovlev, V

    2011-01-01

    Project-X is the proposed high intensity proton facility to be built at Fermilab, US. Its Superconducting Linac, to be used at first stage of acceleration, will be operated in continuous wave (CW) mode. The Linac is divided into three sections on the basis of operating frequencies & six sections on the basis of family of RF cavities to be used for the acceleration of beam from 2.5 MeV to 3 GeV. The transition from one section to another can limit the acceptance of the Linac if these are not matched properly. We performed a study to calculate the acceptance of the Linac in both longitudinal and transverse plane. Investigation of most sensitive area which limits longitudinal acceptance and study of influence of failure of beam line elements at critical position, on acceptance are also performed.

  4. Superconducting linac beam dynamics with high-order maps for RF resonators

    CERN Document Server

    Geraci, A A; Pardo, R C; 10.1016/j.nima.2003.11.177

    2004-01-01

    The arbitrary-order map beam optics code COSY Infinity has recently been adapted to calculate accurate high-order ion-optical maps for electrostatic and radio-frequency accelerating structures. The beam dynamics of the superconducting low-velocity positive-ion injector linac for the ATLAS accelerator at Argonne National Lab is used to demonstrate some advantages of the new simulation capability. The injector linac involves four different types of superconducting accelerating structures and has a total of 18 resonators. The detailed geometry for each of the accelerating cavities is included, allowing an accurate representation of the on- and off-axis electric fields. The fields are obtained within the code from a Poisson-solver for cylindrically symmetric electrodes of arbitrary geometry. The transverse focusing is done with superconducting solenoids. A detailed comparison of the transverse and longitudinal phase space is made with the conventional ray-tracing code LINRAY. The two codes are evaluated for ease ...

  5. MODEL BENCHMARK WITH EXPERIMENT AT THE SNS LINAC

    Energy Technology Data Exchange (ETDEWEB)

    Shishlo, Andrei P [ORNL; Aleksandrov, Alexander V [ORNL; Liu, Yun [ORNL; Plum, Michael A [ORNL

    2016-01-01

    The history of attempts to perform a transverse match-ing in the Spallation Neutron Source (SNS) superconduct-ing linac (SCL) is discussed. The SCL has 9 laser wire (LW) stations to perform non-destructive measurements of the transverse beam profiles. Any matching starts with the measurement of the initial Twiss parameters, which in the SNS case was done by using the first four LW stations at the beginning of the superconducting linac. For years the consistency between data from all LW stations could not be achieved. This problem was resolved only after significant improvements in accuracy of the phase scans of the SCL cavities, more precise analysis of all available scan data, better optics planning, and the initial longitudi-nal Twiss parameter measurements. The presented paper discusses in detail these developed procedures.

  6. Preliminary study on the possible use of superconducting half-wave resonators in the IFMIF Linac

    Energy Technology Data Exchange (ETDEWEB)

    Mosnier, A.; Uriot, D

    2007-07-01

    The driver of the International Fusion Materials Irradiation Facility (IFMIF) consists of two 125 mA, 40 MeV cw deuteron linacs, providing a total of 10 MW beam power to the liquid lithium target. A superconducting (SC) solution for the 5 to 40 MeV accelerator portion could offer some advantages compared with the copper Alvarez-type Drift Tube Linac reference design: linac length reduction and significant plug power saving. A SC scheme, based on multi-gap CH-structures has been proposed by IAP in Frankfurt. Another SC scheme, using half-wave resonators (HWR), which are in an advanced stage of development at different places, would allow a shorter focusing lattice, resulting in a safe beam transportation with minimal beam loss. In order to investigate the feasibility of the superconducting HWR option, faced with the very high space charge regime of the IFMIF linac, beam dynamics calculations have been performed. This paper presents an optimized linac layout, together with extensive multi-particle simulations including various field and alignment errors. (authors)

  7. Present and next steps of the JAERI superconducting rf linac based FEL program

    Energy Technology Data Exchange (ETDEWEB)

    Minehara, E.J.; Yamauchi, T.; Sugimoto, M. [FEL Laboratory at Tokai, Advanced Photon Research Center, Kansai Research Establishment, Japan Atomic Energy Research Institute, Tokai, Ibaraki (JP)] (and others)

    2000-03-01

    The JAERI superconducting rf linac based FEL has successfully been lased to produce a 0.3 kW FEL light and 100 kW or larger electron beam output in quasi continuous wave operation in 1999. The 1 kW class output as our present program goal will be achieved to improve the optical out coupling method in the FEL optical resonator, the electron gun, and the electron beam optics in the JAERI FEL driver. As our next 5 year program goal is the 100 kW class FEL light and a few tens MW class electron beam output in average, quasi continuous wave operation of the light and electron beam will be planned in the JAERI superconducting rf linac based FEL facility. Conceptual design options needed for such a very high power operation and shorter wavelength light sources will be discussed to improve and to upgrade the exciting facility. (author)

  8. Beam simulations with initial bunch noise in superconducting RF proton linacs

    CERN Document Server

    Tückmantel, J

    2010-01-01

    Circular machines are plagued by coupled bunch instabilities (CBI), driven by impedance peaks, where then all cavity higher order modes (HOMs) are possible drivers. Limiting the CBI growth rate is the fundamental reason that all superconducting rf cavities in circular machines are equipped with HOM dampers. The question arises if for similar reasons HOM damping would not be imperative also in high current superconducting rf proton linacs. Therefore we have simulated the longitudinal bunched beam dynamics in such machines, also including charge and position noise on the injected bunches. Simulations were executed for a generic linac with properties close to the planned SPL at CERN, SNS, or Project X at FNAL. It was found that with strong bunch noise and monopole HOMs with high Qext large beam scatter, possibly exceeding the admittance of a receiving machine, cannot be excluded. A transverse simulation shows similar requirements. Therefore including initial bunch noise in any beam dynamic study on superconducti...

  9. Spatial and temporal beam profile monitor with nanosecond resolution for CERN's Linac4 and Superconducting Proton Linac

    CERN Document Server

    Hori, M

    2008-01-01

    The Linac4, now being developed at CERN, will provide 160-MeV H- beams of high intensity . Before this beam can be injected into the CERN Proton Synchrotron Booster or future Superconducting Proton Linac for further acceleration, some sequences of 500-ps-long micro-bunches must be removed from it, using a beam chopper. These bunches, if left in the beam, would fall outside the longitudinal acceptance of the accelerators and make them radioactive. We developed a monitor to measure the time structure and spatial profile of this chopped beam, with respective resolutions and . Its large active area and dynamic range also allows investigations of beam halos. The ion beam first struck a carbon foil, and secondary electrons emerging from the foil were accelerated by a series of parallel grid electrodes. These electrons struck a phosphor screen, and the resulting image of the scintillation light was guided to a thermoelectrically cooled, charge-coupled device camera. The time resolution was attained by applying high-...

  10. Spiral 2 Cryogenic System for The Superconducting LINAC

    Science.gov (United States)

    Ghribi, A.; Bernaudin, P.-E.; Bert, Y.; Commeaux, C.; Houeto, M.; Lescalié, G.

    2017-02-01

    SPIRAL 21 is a rare isotope accelerator dedicated to the production of high intensity beams (E = 40 MeV, I = 5 mA). The driver is a linear accelerator (LINAC) that uses bulk Niobium made quarter wave RF cavities. 19 cryomodules inclose one or two cavities respectively for the low and the high energy sections. To supply the 1300 W at 4.2 K required to cool down the LINAC, a cryogenic system has been set up. The heart of the latter is a 3 turbines geared HELIAL®LF (ALAT2) cold box that delivers both the liquid helium for the cavities and the 60 K Helium gaz for the thermal screens. 19 valve-boxes insure cryogenic fluid distribution and management. Key issues like cool down speed or cavity RF frequency stability are closely linked to the cryogenic system management. To overcome these issues, modelling and simulation efforts are being undertaken prior to the first cool down trials. In this paper, we present a status update of the Spiral 2 cryogenic system and the cool down strategy considered for its commissioning.

  11. Superconducting Linac and associated accelerator development at NSC

    Indian Academy of Sciences (India)

    Amit Roy

    2001-08-01

    There has been significant progress in the programme to develop a superconducting linear accelerator as a booster for the Pelletron accelerator at the Nuclear Science Centre. This paper presents the current status of the development in all the major components of the accelerator.

  12. Comparison of coaxial higher order mode couplers for the CERN Superconducting Proton Linac study

    Directory of Open Access Journals (Sweden)

    K. Papke

    2017-06-01

    Full Text Available Higher order modes (HOMs may affect beam stability and refrigeration requirements of superconducting proton linacs such as the Superconducting Proton Linac, which is studied at CERN. Under certain conditions beam-induced HOMs can accumulate sufficient energy to destabilize the beam or quench the superconducting cavities. In order to limit these effects, CERN considers the use of coaxial HOM couplers on the cutoff tubes of the 5-cell superconducting cavities. These couplers consist of resonant antennas shaped as loops or probes, which are designed to couple to potentially dangerous modes while sufficiently rejecting the fundamental mode. In this paper, the design process is presented and a comparison is made between various designs for the high-beta SPL cavities, which operate at 704.4 MHz. The rf and thermal behavior as well as mechanical aspects are discussed. In order to verify the designs, a rapid prototype for the favored coupler was fabricated and characterized on a low-power test-stand.

  13. Summary of the Superconducting RF Linac for Muon Collider and Neutrino Factory

    Energy Technology Data Exchange (ETDEWEB)

    Galambos, J.; /Oak Ridge; Garoby, R.; /CERN; Geer, S.; /Fermilab

    2010-01-01

    Project-X is a proposed project to be built at Fermi National Accelerator Laboratory with several potential missions. A primary part of the Project-X accelerator chain is a Superconducting linac, and In October 2009 a workshop was held to concentrate on the linac parameters. The charge of the workshop was to 'focus only on the SRF linac approaches and how it can be used'. The focus of Working Group 2 of this workshop was to evaluate how the different linac options being considered impact the potential realization of Muon Collider (MC) and Neutrino Factory (NF) applications. In particular the working group charge was, 'to investigate the use of a multi-megawatt proton linac to target, phase rotate and collect muons to support a muon collider and neutrino factory'. To focus the working group discussion, three primary questions were identified early on, to serve as a reference: (1) What are the proton source requirements for muon colliders and neutrino factories? (2) What are the issues with respect to realizing the required muon collider and neutrino factory proton sources - (a) General considerations and (b) Considerations specific to the two linac configurations identified by Project-X? (3) What things need to be done before we can be reasonably confident that ICD1/ICD2 can be upgraded to provide the neutrino factory/muon collider needs? A number of presentations were given, and are available at the workshop web-site. This paper does not summarize the individual presentations, but rather addresses overall findings as related to the three guiding questions listed above.

  14. Feasibility of Using Conductively Cooled Magnets in Cryomidules of Superconducting Linacs

    Energy Technology Data Exchange (ETDEWEB)

    Terechkine, I. [Fermilab; Cheban, Cheban,S. [Fermilab; Nicol. T., Nicol. T. [Fermilab; Poloubotko, V. [Fermilab; Sergatskov, D. [Fermilab

    2013-09-01

    As part of a search for optimal ways to configure cryomodules of the low-beta section of a high-current, high-power superconducting linac, an option of using conductively cooled superconducting focusing lenses was evaluated. Superconducting magnet was installed inside existing test cryostat, which was modified by adding current feed-throughs and two conductively cooled current leads. Each lead was equipped with heat sinks at the temperatures of liquid nitrogen and liquid helium. The magnet was mounted inside the cryostat on an individual heat sink plate, and thermometers were installed on the leads, heat sinks, and on the magnet. In this report we provide some details of the test setup and analyse results of the temperature measurements.

  15. The focusing properties of both normal and superconducting low energy CW proton Linacs

    CERN Document Server

    Zhihui, Li

    2016-01-01

    The continue wave (CW) high current proton linac has wide applications as the front end of the high power proton machines. The low energy part is the most difficult one and there is no widely accepted solution yet. Both normal conducting and superconducting acceleration structures are thought to be the possible solutions. Although the characteristics of normal conducting structures and superconducting ones are quite different, such as acceleration voltage, maximum electric field and so on, we found the focusing properties of the lattice composed by these two acceleration structures are quite similar for different reasons. The advantages and disadvantages of lattices composed of both the normal conducting and superconducting structures are analysed from the beam dynamics point of view, and their constraints on beam main parameters are discussed.

  16. Superconducting low-velocity linac for the Argonne positive-ion injector

    Energy Technology Data Exchange (ETDEWEB)

    Shepard, K.W.; Markovich, P.K.; Zinkann, G.P.; Clifft, B.; Benaroya, R.

    1989-01-01

    A low-velocity superconducting linac has been developed as part of a positive-ion injector system, which is replacing a 9 MV tandem as the injector for the ATLAS accelerator. The linac consists of an independently phased array of resonators, and is designed to accelerate various ions over a velocity range .008 < v/c < .06. The resonator array is formed of four different types of superconducting interdigital structures. The linac is being constructed in three phases, each of which will cover the full velocity range. Successive phases will increase the total accelerating potential and permit heavier ions to be accelerated. Assembly of the first phase was completed in early 1989. In initial tests with beam, a five-resonator array provided approximately 3.5 MV of accelerating potential and operated without difficulty for several hundred hours. The second phase is scheduled for completion in late 1989, and will increase the accelerating potential to more than 8 MV. 5 refs., 2 figs., 1 tab.

  17. High duty factor Plasma Generator for CERN’s Superconducting Proton Linac

    CERN Document Server

    Lettry, J; Scrivens, R; Chaudet, E; Faircloth, D; Favre, G; Geisser, JM; Kuchler, D; Mathot, S; Midttun, O; Paoluzzi, M; Schmitzer, C; Steyaert, D

    2010-01-01

    CERN’s Linac4 is a 160 MeV linear accelerator currently under construction. It will inject negatively charged hydrogen ions into CERN’s PS-Booster. Its ion source is a non-cesiated RF driven H- volume source directly inspired from the one of DESY and is aimed to deliver pulses of 80 mA of H- during 0.4 ms at a 2 Hz repetition rate. The Superconducting Proton Linac (SPL) project is part of the luminosity upgrade of the LHC, it consists of an extension of Linac4 up to 5 GeV and is foreseen to deliver protons to a future 50 GeV Synchrotron (PS2). For the SPL high power option (HP-SPL), the ion source would deliver pulses of 80 mA of H- during 1.2 ms and operate at a 50 Hz repetition rate. This significant upgrade motivates the design of the new water cooled plasma generator presented in this paper. Its engineering is based on the results of a finite element thermal study of the Linac4 H- plasma generator that identified critical components and thermal barriers. A cooling system is proposed which achieves the...

  18. CW Superconducting RF Photoinjector Development for Energy Recovery Linacs

    Energy Technology Data Exchange (ETDEWEB)

    Neumann A.; Rao T.; Anders, W.; Dirsat, M.; Frahm, A. Jankowiak, A.; Kamps, T.; Knobloch, J.; Kugeler, O.; Quast, T.; Rudolph, J.; Schenk, M.; Schuster, M.; Smedley, J.; Sekutowicz, J.; Kneisel, P.; Nietubyc, R.; Will, I.

    2010-10-31

    ERLs have the powerful potential to provide very high current beams with exceptional and tailored parameters for many applications, from next-generation light sources to electron coolers. However, the demands placed on the electron source are severe. It must operate CW, generating a current of 100 mA or more with a normalized emittance of order 1 {micro}m rad. Beyond these requirements, issues such as dark current and long-term reliability are critical to the success of ERL facilities. As part of the BERLinPro project, Helmholtz Zentrum Berlin (HZB) is developing a CWSRF photoinjector in three stages, the first of which is currently being installed at HZB's HoBiCaT facility. It consists of an SRF-cavity with a Pb cathode and a superconducting solenoid. Subsequent development stages include the integration of a high-quantum-efficiency cathode and RF components for high-current operation. This paper discusses the first stage towards an ERL-suitable SRF photoinjector, the present status of the facility and first cavity tests.

  19. Development of niobium spoke cavities for a superconducting light-ion Linac.

    Energy Technology Data Exchange (ETDEWEB)

    Shepard, K. W.

    1998-11-18

    This paper reports the development of 350 MHz niobium superconducting cavities for the velocity range 0.2< v/c <0.6. Such cavities could be used to form a linac of exceptional flexibility, capable of efficiently accelerating beams of either protons, deuterons, or any of a wide range of light ions, at intensities sufficient for a production beam for a radioactive beam facility. Results of numerical modeling for several resonator geometries are presented. The design and construction status of prototype niobium cavities is discussed.

  20. Development of niobium spoke cavities for a superconducting light-ion linac

    Energy Technology Data Exchange (ETDEWEB)

    Shepard, K W; Kedzie, M; Delayen, J R; Piller, C

    1998-08-01

    This paper reports the development of 350 MHz niobium superconducting cavities for the velocity range 0.2 < v/c < 0.6. Such cavities could be used to form a linac of exceptional flexibility, capable of efficiently accelerating beams of either protons, deuterons, or any of a wide range of ions, at intensities sufficient for a production beam for a radioactive facility. Results of numerical modeling for several resonator geometries are presented. The design and construction status of prototype niobium cavities is discussed.

  1. Design of the MYRRHA 17-600 MeV Superconducting Linac

    CERN Document Server

    Biarrotte, J-L; Bouly, F; Carneiro, J-P; Vandeplassche, D

    2013-01-01

    The goal of the MYRRHA project is to demonstrate the technical feasibility of transmutation in a 100MWth Accelerator Driven System (ADS) by building a new flexible irradiation complex in Mol (Belgium). The MYRRHA facility requires a 600 MeV accelerator delivering a maximum proton flux of 4 mA in continuous operation, with an additional requirement for exceptional reliability. This paper will briefly describe the beam dynamics design of the main superconducting linac section which covers the 17 to 600 MeV energy range and requires enhanced fault-tolerance capabilities.

  2. Design of energy-recovery transport for the JAERI FEL driven by a superconducting linac

    CERN Document Server

    Hajima, R; Nagai, R; Kikuzawa, N; Nishimori, N; Shizuma, T; Minehara, E J; Vinokurov, N A

    2000-01-01

    A high-average power free-electron laser driven by a superconducting linac has been developed in Japan Atomic Energy Research Institute (JAERI), and stable laser output over 0.1 kW in infrared region is now available. For further increasing of FEL output power, installing energy-recovery transport has been planned. The lattice design for the energy-recovery transport is discussed in the present paper. It is found that a recirculation transport, which fulfills the requirements for energy acceptance and isochronicity, can be realized by adding another triple-bend arc to the existing beam line.

  3. Developments and Tests of a 700 MHz Cryomodule for the Superconducting Linac of MYRRHA

    CERN Document Server

    Bouly, F; Bosotti, A; Pierini, P; El Yakoubi, M; Berthelot, S; Biarrotte, J-L; Joly, C; Lesrel, J; Rampnoux, E

    2013-01-01

    The MYRRHA projects aims at the construction of an Accelerator Driven System demonstrator. The criticality will be sustained by an external spallation neutron flux; produced thanks to a 600 MeV high intensity proton beam. This beam will be delivered by a superconducting linac which must fulfil very stringent reliability requirements. To carry out “real scale” reliability-oriented experiments a 700 MHz Cryomodule was developed. Several tests were performed to commission the experimental set-up. We review here the obtained results and the lessons learnt by operating this module, as well as the on-going developments.

  4. Influence of higher order modes on the beam stability in the high power superconducting proton linac

    CERN Document Server

    Schuh, M; Gerigk, F; Tuckmantel, J

    2011-01-01

    Higher order modes (HOMs) can severely limit the operation of superconducting cavities in a linear accelerator with high beam current, high duty factor, and complex pulse structure. The full HOM spectrum has to be analyzed in order to identify potentially dangerous modes already during the design phase and to define their damping requirements. For this purpose a dedicated beam simulation code simulation of higher order mode dynamics (SMD) focused on beam-HOM interaction was developed, taking into account important effects like the HOM frequency spread, beam input jitter, different chopping patterns, as well as klystron and alignment errors. Here, SMD is used to investigate the influence of HOMs in detail in the superconducting proton linac at CERN and their potential to drive beam instabilities in the longitudinal and transverse plane.

  5. Influence of higher order modes on the beam stability in the high power superconducting proton linac

    Directory of Open Access Journals (Sweden)

    Marcel Schuh

    2011-05-01

    Full Text Available Higher order modes (HOMs can severely limit the operation of superconducting cavities in a linear accelerator with high beam current, high duty factor, and complex pulse structure. The full HOM spectrum has to be analyzed in order to identify potentially dangerous modes already during the design phase and to define their damping requirements. For this purpose a dedicated beam simulation code simulation of higher order mode dynamics (SMD focused on beam-HOM interaction was developed, taking into account important effects like the HOM frequency spread, beam input jitter, different chopping patterns, as well as klystron and alignment errors. Here, SMD is used to investigate the influence of HOMs in detail in the superconducting proton linac at CERN and their potential to drive beam instabilities in the longitudinal and transverse plane.

  6. Study of Higher Order Modes in Superconducting Accelerating Structures for Linac Applications

    CERN Document Server

    Schuh, Marcel; Welsch, C P

    2011-01-01

    Higher Order Modes (HOMs) can severely limit the operation of superconducting cavities in a linear accelerator with high beam current, high duty factor and complex pulse structure. Therefore, the full HOM spectrum has to be analysed in detail to identify potentially dangerous modes already during the design phase and to define their damping requirements. For this purpose a dedicated beam dynamics simulation code, Simulation of higher order Mode Dynamics (SMD), focusing on beam-HOM interaction, has been developed in the frame of this project. SMD allows to analyse the beam behaviour under the presence of HOMs, taking into account many important effects, such as for example the HOM frequency spread, beam input jitter, different chopping patterns, as well as klystron and alignment errors. SMD is used to investigate in detail into the effects of HOMs in the Superconducting Proton Linac (SPL) at CERN and in particular their potential to drive beam instabili- ties in the longitudinal and transverse direction. Based...

  7. Cumulative beam break-up study of the spallation neutron source superconducting linac

    CERN Document Server

    Jeon, D; Krafft, G A; Yunn, B; Sundelin, R; Delayen, J; Kim, S; Doleans, M

    2002-01-01

    Beam instabilities due to High Order Modes (HOMs) are a concern to superconducting (SC) linacs such as the Spallation Neutron Source (SNS) linac. The effects of pulsed mode operation on transverse and longitudinal beam breakup instability are studied for H sup - beam in a consistent manner for the first time. Numerical simulation indicates that cumulative transverse beam breakup instabilities are not a concern in the SNS SC linac, primarily due to the heavy mass of H sup - beam and the HOM frequency spread resulting from manufacturing tolerances. As little as +-0.1 MHz HOM frequency spread stabilizes all the instabilities from both transverse HOMs, and also acts to stabilize the longitudinal HOMs. Such an assumed frequency spread of +-0.1 MHz HOM is small, and hence conservative compared with measured values of sigma=0.00109(f sub H sub O sub M -f sub 0)/f sub 0 obtained from Cornell and the Jefferson Lab Free Electron Laser cavities. However, a few cavities may hit resonance lines and generate a high heat lo...

  8. A superconducting CW-LINAC for heavy ion acceleration at GSI

    Science.gov (United States)

    Barth, Winfried; Aulenbacher, Kurt; Basten, Markus; Dziuba, Florian; Gettmann, Viktor; Miski-Oglu, Maksym; Podlech, Holger; Yaramyshev, Stepan

    2017-03-01

    Recently the Universal Linear Accelerator (UNILAC) serves as a powerful high duty factor (25%) heavy ion beam accelerator for the ambitious experiment program at GSI. Beam time availability for SHE (Super Heavy Element)-research will be decreased due to the limitation of the UNILAC providing Uranium beams with an extremely high peak current for FAIR simultaneously. To keep the GSI-SHE program competitive on a high level and even beyond, a standalone superconducting continuous wave (100% duty factor) LINAC in combination with the upgraded GSI High Charge State injector is envisaged. In preparation for this, the first LINAC section (financed by HIM and GSI) will be tested with beam in 2017, demonstrating the future experimental capabilities. Further on the construction of an extended cryo module comprising two shorter Crossbar-H cavities is foreseen to test until end of 2017. As a final R&D step towards an entire LINAC three advanced cryo modules, each comprising two CH cavities, should be built until 2019, serving for first user experiments at the Coulomb barrier.

  9. Initial studies of Bremsstrahlung energy deposition in small-bore superconducting undulator structures in linac environments

    Energy Technology Data Exchange (ETDEWEB)

    Cremer, T.; Tatchyn, R. [Stanford Univ., CA (United States)

    1995-12-31

    One of the more promising technologies for developing minimal-length insertion devices for linac-driven, single-pass Free Electron Lasers (FELs) operating in the x-ray range is based on the use of superconducting (SC) materials. In recent FEL simulations, for example, a bifilar helical SC device with a 2 cm period and 1.8 T field was found to require a 30 m saturation length for operation at 1.5{Angstrom} on a 15 GeV linac, more than 40% shorter than an alternative hybrid/permanent magnet (hybrid/PM) undulator. AT the same time, however, SC technology is known to present characteristic difficulties for insertion device design, both in engineering detail and in operation. Perhaps the most critical problem, as observed, e.g., by Madey and co-workers in their initial FEL experiments, was the frequent quenching induced by scattered electrons upstream of their (bifilar) device. Postulating that this quenching was precipitated by directly-scattered or bremsstrahlung-induced particle energy deposited into the SC material or into material contiguous with it, the importance of numerical and experimental characterizations of this phenomenon for linac-based, user-facility SC undulator design becomes evident. In this paper we discuss selected prior experimental results and report on initial EGS4 code studies of scattered and bremsstrahlung induced particle energy deposition into SC structures with geometries comparable to a small-bore bifilar helical undulator.

  10. Superconducting, energy variable heavy ion linac with constant β, multicell cavities of CH-type

    Directory of Open Access Journals (Sweden)

    S. Minaev

    2009-12-01

    Full Text Available An energy variable ion linac consisting of multigap, constant-β cavities was developed. The effect of phase sliding, unavoidable in any constant-β section, is leading to a coherent rf phase motion, which fits well to the H-type structures with their long π-mode sections and separated lenses. The exact periodicity of the cell lengths within each cavity results in technical advantages, such as higher calculation accuracy when only one single period can be simulated, simpler manufacturing, and tuning. This is most important in the case of superconducting cavities. By using this concept, an improved design for a 217 MHz cw superconducting heavy ion linac with energy variation has been worked out. The small output energy spread of ±3  AkeV is provided over the whole range of energy variation from 3.5 to 7.3 AMeV. These capabilities would allow for a competitive research in the field of radiochemistry and for a production of super heavy elements (SHE, especially. A first 19-cell cavity of that type was designed, built, and rf tested successfully at the Institute for Applied Physics (IAP Frankfurt. A 325.224 MHz, seven-cell cavity with constant β=0.16 is under development and will be operated in a frequency controlled mode. It will be equipped with a power coupler and beam tests with Unilac beams at GSI are foreseen.

  11. A controller for 97 MHz super-conducting QWR for NSC LINAC booster

    Indian Academy of Sciences (India)

    Gopal Joshi; C I Sujo; Bhuban Sahu; Ashutosh Pandey; Ajith Kumar; Jitendra Karande

    2002-12-01

    A resonator controller has been implemented to stabilize the amplitude and phase of rf fields in the super-conducting resonators of NSC LINAC. Due to reduced losses these resonators have intrinsic band width of the order of 0.1 Hz at 97 MHz whereas the vibration-induced center frequency changes are of the order of a few tens of hertz. In the control strategy followed, the resonator is made the frequency selective part of an oscillator. The phase lock is achieved by dynamically adding a phase shift in the oscillator. A slow tuner minimizes the slow drifts in the resonator center frequency. In this paper we present the control strategy, implementation details and performance obtained with this controller.

  12. JAERI superconducting RF linac-based free-electron laser-facility

    CERN Document Server

    Minehara, E J; Nagai, R; Kikuzawa, N; Sugimoto, M; Hajima, R; Shizuma, T; Yamauchi, T; Nishimori, N

    2000-01-01

    Recently, the JAERI superconducting RF linac based FEL has been successfully lased to produce 0.36 kW of FEL light using a 100 kW electron beam in quasi-continuous wave operation. A 1 kW class laser is our present program goal, and will be achieved by improving the optical out coupling in the FEL optical resonator, the electron gun, and the electron beam optics in the JAERI FEL driver. Our next 5-year program goal is to produce a 100 kW-class FEL laser and multi-MW class electron beam in average, quasi-continuous wave operation. Conceptual and engineering design options needed for such a very high-power operation will be discussed to improve and to upgrade the existing facility.

  13. Continuous wave superconducting radio frequency electron linac for nuclear physics research

    Science.gov (United States)

    Reece, Charles E.

    2016-12-01

    CEBAF, the Continuous Electron Beam Accelerator Facility, has been actively serving the nuclear physics research community as a unique forefront international resource since 1995. This cw electron linear accelerator (linac) at the U.S. Department of Energy's Thomas Jefferson National Accelerator Facility (Jefferson Lab) has continued to evolve as a precision tool for discerning the structure and dynamics within nuclei. Superconducting rf (SRF) technology has been the essential foundation for CEBAF, first as a 4 GeV machine, then 6 GeV, and currently capable of 12 GeV. We review the development, implementation, and performance of SRF systems for CEBAF from its early beginnings to the commissioning of the 12 GeV era.

  14. SRF LINAC for future extension of the PEFP

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Han Sung; Kwon, Hyeok Jung; Seol, Kyoung Tae; Jang, Ji Ho; Cho, Yong Sub [Proton Engineering Frontier Project, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-04-15

    A study on the superconducting RF linac is underway in order to increase the beam energy up to 1 GeV by extending the Proton Engineering Frontier Project (PEFP) 100-MeV linac. The operating frequency of the PEFP superconducting linac (SCL) is 700 MHz, which is determined by the fact that the frequency of the existing normal conducting linac is 350 MHz. A preliminary study on the beam dynamics showed that two types of cavities with geometrical betas of 0.50 and 0.74 could cover the entire energy range from 100 MeV to 1 GeV. An inductive output tube (IOT) based RF system is under consideration as a high-power RF source for the SCL due to its low operating voltage and high efficiency. As a prototyping activity for a reduced beta cavity, a five-cell cavity with a geometrical beta of 0.42 was designed and fabricated. A vertical test of the prototype cavity at low temperatures was performed to check the performance of the cavity. The design study and the prototyping activity for the PEFP SCL will be presented in this paper.

  15. Updating the CSNS injector linac to 250 MeV with superconducting double-spoke cavities

    CERN Document Server

    Zhi-Hui, LI

    2014-01-01

    In order to update the beam power from 100 kW to 250 kW in China spallation neutron source (CSNS) Phase II, one of the important measures is to replace the 80 meters long beam transport line between the present 80 MeV linac injector and the RCS to another kind of acceleration structure. In this paper, we proposed a scheme based on 324 MHz double-spoke superconducting cavities. Unlike the superconducting elliptical cavity and normal conducting CCL structure, the double-spoke cavity belongs to TE mode structure and has smaller transvers dimension compared with that of TH mode one. It can work at base frequency as the DTL section, so that the cost and complexity of the RF system will be much decreased, and the behaviors of the beam dynamics are also improved significantly because of the low charge density and larger longitudinal acceptance. Furthermore, because of the relatively longer interactive length between charged particle and the electromagnetic field per cell, it needs relatively less cell numbers and it...

  16. RF power upgrade at the superconducting 1.3 GHz CW LINAC “ELBE” with solid state amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Büttig, Hartmut, E-mail: buettig@hzdr.de [Radiation Source ELBE, Helmholtz Zentrum Dresden-Rossendorf (Germany); Arnold, A.; Büchner, A.; Justus, M.; Kuntsch, M.; Lehnert, U.; Michel, P.; Schurig, R.; Staats, G.; Teichert, J. [Radiation Source ELBE, Helmholtz Zentrum Dresden-Rossendorf (Germany)

    2013-03-11

    The RF power for the superconducting 1.3 GHz CW LINAC “ELBE” has been doubled from less than 10 kW to 20 kW per cavity. In January 2012 the four 10 kW klystrons used to drive the four superconducting cavities of the LINAC have been replaced by pairs of 10 kW solid state power amplifiers (SSPA). ELBE is now worldwide the first 1.3 GHz CW LINAC equipped with solid state RF power amplifiers. This technical note details on this project. -- Highlights: ► We report the first installation of 10 kW solid state RF-amplifiers at 1.3 GHz CW LINAC. ► The sc. cavities of “ELBE” are now driven by a pair of 10 kW solid state amplifiers (SSPA). ► The RF-power upgrade allows doubling the electron beam current (CW). ► Advantages of the new RF system are high reliability, easy service and lower costs.

  17. Dynamic compensation of an rf cavity failure in a superconducting linac

    Directory of Open Access Journals (Sweden)

    Jean-Luc Biarrotte

    2008-07-01

    Full Text Available An accelerator driven system (ADS for transmutation of nuclear waste typically requires a 600 MeV–1 GeV accelerator delivering a proton flux of a few mA for demonstrators, and of a few tens of mA for large industrial systems. Such a machine belongs to the category of the high-power proton accelerators, with an additional requirement for exceptional “reliability”: because of the induced thermal stress to the subcritical core, the number of unwanted “beam trips” should not exceed a few per year, a specification that is several orders of magnitude above usual performance. In order to meet this extremely high reliability, the accelerator needs to implement, to the maximum possible extent, a fault-tolerance strategy that would allow beam operation in the presence of most of the envisaged faults that could occur in its beam line components, and in particular rf systems’ failures. This document describes the results of the simulations performed for the analysis of the fault-tolerance capability of the XT-ADS superconducting linac in the case of an rf cavity failure. A new simulation tool, mixing transient rf behavior of the accelerating cavities with full 6D description of the beam dynamics, has been developed for this purpose. Fast fault-recovery scenarios are proposed, and required research and development is identified.

  18. Superconducting Cavity Cryomodule Designs for the Next Generation of CW Linacs: Challenges and Options

    Energy Technology Data Exchange (ETDEWEB)

    Nicol, Thomas [Fermilab; Orlov, Yuriy [Fermilab; Peterson, Thomas [Fermilab; Yakovlev, Vyacheslav [Fermilab

    2014-07-01

    The designs of nearly all superconducting RF (SRF) linacs over the last several years, with one notable exception being CEBAF at Jefferson Lab, have assumed pulsed beam operation with relatively low duty factors. These include the XFEL at DESY, the ILC, the original configuration for Project X at Fermilab, as well as several others. Recently proposed projects, on the other hand, including the LCLS-II at SLAC, the newly configured low and medium energy sections for Project X, and FRIB at Michigan State, to name a few, assume continuous wave or CW operation on quite a large scale with ambitious gradients and cavity performance requirements. This has implications in the cavity design as well as in many parts of the overall cryomodule due to higher dynamic heat loads in the cavities themselves and higher heat loads in the input and high-order-mode (HOM) couplers. Piping internal to the cryomodule, the effectiveness of thermal intercepts, the size of integrated heat exchangers, and many other aspects of the overall design are also affected. This paper will describe some of these design considerations as we move toward the next generation of accelerator projects.

  19. A Multi-MW Proton/Electron Linac at KEK

    CERN Document Server

    Belusevic, Radoje

    2014-01-01

    It is proposed that a multi-MW superconducting proton/electron linac (SCL) and a proton injector (PI) be built at KEK. The 3 GeV PI would serve both as an injector to the SCL and a source of proton beams that could be used to copiously produce neutrons and muons. Protons accelerated by the SCL to 20 GeV would be transferred through the KEK Tristan ring in order to create neutrino, kaon and muon beams for fixed-target experiments. At a later stage, a 60 GeV proton synchrotron could be installed inside the Tristan ring. The SCL, comprising 1.3 GHZ superconducting ILC-type rf cavities, could also accelerate polarized or unpolarized electron beams. After acceleration, electrons may traverse an XFEL undulator, or could be used to produce polarized positrons. An SCL-based synchrotron light source for applications in materials science and medicine is also envisaged. The proposed facility would be constructed using the existing KEK accelerator infrastructure.

  20. Conceptual Design of the Low-Power and High-Power SPL A Superconducting H$^-$ Linac at CERN

    CERN Document Server

    Atieh, S; Aviles Santillana, I; Bartmann, W; Borburgh, J; Brunner, O; Calatroni, S; Capatina, O; Chambrillon, J; Ciapala, E; Eshraqi, M; Ferreira, L; Garoby, R; Goddard, B; Hessler, C; Hofle, W; Horvath-Mikulas, S; Junginger, T; Kozlova, E; Lebbos, E; Lettry, J; Liao, K; Lombardi, A M; Macpherson, A; Montesinos, E; Nisbet, D; Otto, T; Paoluzzi, M; Papke, K; Parma, V; Pillon, F; Posocco, P; Ramberger, S; Rossi, C; Schirm, K; Schuh, M; Scrivens, R; Torres Sanchez, R; Valuch, D; Valverde Alonso, N; Wegner, R; Weingarten, W; Weisz, S

    2014-01-01

    The potential for a superconducting proton linac (SPL) at CERN started to be seriously considered at the end of the 1990s. In the first conceptual design report (CDR), published in 2000 [1], most of the 352 MHz RF equipment from LEP was re-used in an 800 m long linac, and the proton beam energy was limited to 2.2 GeV. During the following years, the design was revisited and optimized to better match the needs of a high-power proton driver for neutrino physics. The result was a more compact (470 m long) accelerator capable of delivering 5 MW of beam power at 3.5 GeV, using state-of-the-art superconducting RF cavities at 704 MHz. It was described in a second CDR, published in 2006 [2]. Soon afterwards, when preparation for increasing the luminosity of the LHC by an order of magnitude beyond nominal became an important concern, a low-power SPL (LP-SPL) was studied as a key component in the renovation of the LHC injector complex. The combination of a 4 GeV LP-SPL injecting into a new 50 GeV synchrotron (PS2) was ...

  1. SUPERCONDUCTING LINAC UPGRADE PLAN FOR THE SECOND TARGET STATION PROJECT AT SNS

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang-Ho [ORNL; Doleans, Marc [ORNL; Galambos, John D [ORNL; Howell, Matthew P [ORNL; Mammosser, John [ORNL

    2015-01-01

    The beam power of the Linac for the Second Target Station (STS) at the Spallation Neutron Source (SNS) will be doubled to 2.8 MW. For the energy upgrade, seven additional cryomodules will be installed in the reserved space at the end of the linac tunnel to produce linac output energy of 1.3 GeV. The cryomodules for STS will have the same physical length but will incorporate some design changes based on the lessons learned from operational experience over the last 10 years and from the high beta spare cryomodule developed in house. The average macro-pulse beam current for the STS will be 38 mA which is about a 40 % increase from the present beam current for 1.4 MW operation. Plans for the new cryomodules and for the existing cryomodules to support higher beam current for the STS are presented in this paper.

  2. Superconducting Resonators Development for the FRIB and ReA Linacs at MSU: Recent Achievements and Future Goals

    Energy Technology Data Exchange (ETDEWEB)

    Facco, A; Binkowski, J; Compton, C; Crisp, J L; Dubbs, L J; Elliot, K; Harle, L L; Hodek, M; Johnson, M J; Leitner, D; Leitner, M; Malloch, I M; Miller, S J; Oweiss, R; Popielarski, J; Popielarski, L; Saito, K; Wei, J; Wlodarczak, J; Xu, Y; Zhang, Y; Zheng, Z; Burrill, A; Davis, G K; Macha, K

    2012-07-01

    The superconducting driver and post-accelerator linacs of the FRIB project, the large scale radioactive beam facility under construction at MSU, require the construction of about 400 low-{beta} Quarter-wave (QWR) and Half-wave resonators (HWR) with four different optimum velocities. 1st and 2nd generation prototypes of {beta}{sub 0} = 0.041 and 0.085 QWRs and {beta}{sub 0} = 0.53 HWRs have been built and tested, and have more than fulfilled the FRIB and ReA design goals. The present cavity surface preparation at MSU allowed production of low-{beta} cavities nearly free from field emission. The first two cryostats of {beta}{sub 0} = 0.041 QWRs are now in operation in the ReA3 linac. A 3rd generation design of the FRIB resonators allowed to further improve the cavity parameters, reducing the peak magnetic field in operation and increasing the possible operation gradient, with consequent reduction of the number of required resonators. The construction of the cavities for FRIB, which includes three phases for each cavity type (development, pre-production and production runs) has started. Cavity design, construction, treatment and performance will be described and discussed.

  3. HOM damping properties of fundamental power couplers in the superconducting electron gun of the energy recovery LINAC at Brookhaven National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Hammons, L.; Hahn, H.

    2011-03-28

    Among the accelerator projects under construction at the Relativistic Heavy Ion Collider (RHIC) is an R and D energy recovery LINAC (ERL) test facility. The ERL includes both a five-cell superconducting cavity as well as a superconducting, photoinjector electron gun. Because of the high-charge and high-current demands, effective higher-order mode (HOM) damping is essential, and several strategies are being pursued. Among these is the use of the fundamental power couplers as a means for damping some HOMs. Simulation studies have shown that the power couplers can play a substantial role in damping certain HOMs, and this presentation discusses these studies along with measurements.

  4. An 800-MeV superconducting LINAC to support megawatt proton operations at Fermilab

    CERN Document Server

    Derwent, Paul; Lebedev, Valeri

    2015-01-01

    Active discussion on the high energy physics priorities in the US carried out since summer of 2013 resulted in changes in Fermilab plans for future development of the existing accelerator complex. In particular, the scope of Project X was reduced to the support of the Long Base Neutrino Facility (LBNF) at the project first stage. The name of the facility was changed to the PIP-II (Proton Improvement Plan). This new facility is a logical extension of the existing Proton Improvement Plan aimed at doubling average power of the Fermilab's Booster and Main Injector (MI). Its design and required R&D are closely related to the Project X. The paper discusses the goals of this new facility and changes to the Project X linac introduced to support the goals.

  5. Studies of the superconducting traveling wave cavity for high gradient LINAC

    CERN Document Server

    Avrakhov, Pavel; Kanareykin, Alexei; Solyak, Nikolay; Yakovlev, Vyacheslav P

    2015-01-01

    Use of a traveling wave (TW) accelerating structure with a small phase advance per cell instead of standing wave may provide a significant increase of accelerating gradient in a superconducting linear accelerator. The TW section achieves an accelerating gradient 1.2-1.4 larger than TESLA-shaped standing wave cavities for the same surface electric and magnetic fields. Recent tests of an L-band single-cell cavity with a waveguide feedback demonstrated an accelerating gradient comparable to the gradient in a single-cell ILC-type cavity from the same manufacturer. This article presents the next stage of the 3- cell TW resonance ring development which will be tested in the traveling wave regime. The main simulation results of the microphonics and Lorentz Force Detuning (LFD) are also considered.

  6. SRF test facility for the superconducting LINAC ``RAON'' — RRR property and e-beam welding

    Science.gov (United States)

    Jung, Yoochul; Hyun, Myungook; Joo, Jongdae; Joung, Mijoung

    2015-02-01

    Equipment, such as a vacuum furnace, high pressure rinse (HPR), eddy current test (ECT) and buffered chemical polishing (BCP), are installed in the superconducting radio frequency (SRF) test facility. Three different sizes of cryostats (diameters of 600 mm for a quarter wave resonator (QWR), 900 mm for a half wave resonator (HWR), and 1200 mm for single spoke resonator 1&2 (SSR 1&2)) for vertical RF tests are installed for testing cavities. We confirmed that as-received niobium sheets (ASTM B393, RRR300) good electrical properties because they showed average residual resistance ratio (RRR) values higher than 300. However, serious RRR degradation occurred after joining two pieces of Nb by e-beam welding because the average RRR values of the samples were ˜179, which was only ˜60% of as-received RRR value. From various e-beam welding experiments in which the welding current and a speed at a fixed welding voltage were changed, we confirmed that good welding results were obtained at a 53 mA welding current and a 20-mm/s welding speed at a fixed welding voltage of 150 kV.

  7. Proposal for Reduction of Transverse Emittance of BNL 200 MeV Linac

    CERN Document Server

    Alessi, J; Raparia, D; Weng, W T

    2004-01-01

    BNL plans to upgrade the AGS proton beam from the current 0.14 MW to higher than 1.0 MW and beyond for such a neutrino facility which consists of two major subsystems. First is a 1.2 GeV super-conducting linac (SCL) to replace the booster as injector for the AGS. Second is the performance upgrade for the AGS itself for the higher intensity and repetition rate. For high intensity proton accelerators, such as the upgraded AGS, there are very stringent limitations on uncontrolled beam losses. A direct effect of linac beam emittance is the halo/tail generation in the circulating beam. Studies show the estimated halo/tail generation in the beam for present normalized RMS emittance of linac beam is unacceptable. To reduce the transverse emittance of 200 MeV linac, the existing radio frequency quadrupole linac (RFQ) has to be relocated closer to drift tube linac (DTL) tank 1 to meet emittance requirement for the AGS injection with low loss. This paper will present the various options of matching between RFQ and DTL,...

  8. Low-charge-state linac

    Energy Technology Data Exchange (ETDEWEB)

    Shepard, K.W.; Kim, J.W.

    1995-08-01

    A design is being developed for a low-charge-state linac suitable for injecting ATLAS with a low-charge-state, radioactive beam. Initial work indicates that the existing ATLAS interdigital superconducting accelerating structures, together with the superconducting quadrupole transverse focussing element discussed above, provides a basis for a high-performance low-charge-state linac. The initial 2 or 3 MV of such a linac could be based on a normally-conducting, low-frequency RFQ, possibly combined with 24-MHz superconducting interdigital structures. Beam dynamics studies of the whole low-charge-state post-accelerator section were carried out in early FY 1995.

  9. A non-axial superconducting magnet design for optimized patient access and minimal SAD for use in a Linac-MR hybrid: proof of concept

    Science.gov (United States)

    Yaghoobpour Tari, Shima; Wachowicz, Keith; Fallone, B. Gino

    2017-04-01

    A prototype rotating hybrid magnetic resonance imaging system and linac has been developed to allow for simultaneous imaging and radiation delivery parallel to B 0. However, the design of a compact magnet capable of rotation in a small vault with sufficient patient access and a typical clinical source-to-axis distance (SAD) is challenging. This work presents a novel superconducting magnet design as a proof of concept that allows for a reduced SAD and ample patient access by moving the superconducting coils to the side of the yoke. The yoke and pole-plate structures are shaped to direct the magnetic flux appropriately. The outer surface of the pole plate is optimized subject to the minimization of a cost function, which evaluates the uniformity of the magnetic field over an ellipsoid. The magnetic field calculations required in this work are performed with the 3D finite element method software package Opera-3D. Each tentative design strategy is virtually modeled in this software package, which is externally controlled by MATLAB, with its key geometries defined as variables. The optimization variables are the thickness of the pole plate at control points distributed over the pole plate surface. A novel design concept as a superconducting non-axial magnet is introduced, which could create a large uniform B 0 magnetic field with fewer geometric restriction. This non-axial 0.5 T superconducting magnet has a moderately reduced SAD of 123 cm and a vertical patient opening of 68 cm. This work is presented as a proof of principle to investigate the feasibility of a non-axial magnet with the coils located around the yoke, and the results encourage future design optimizations to maximize the benefits of this non-axial design.

  10. A non-axial superconducting magnet design for optimized patient access and minimal SAD for use in a Linac-MR hybrid: proof of concept.

    Science.gov (United States)

    Yaghoobpour Tari, Shima; Wachowicz, Keith; Gino Fallone, B

    2017-04-21

    A prototype rotating hybrid magnetic resonance imaging system and linac has been developed to allow for simultaneous imaging and radiation delivery parallel to B 0. However, the design of a compact magnet capable of rotation in a small vault with sufficient patient access and a typical clinical source-to-axis distance (SAD) is challenging. This work presents a novel superconducting magnet design as a proof of concept that allows for a reduced SAD and ample patient access by moving the superconducting coils to the side of the yoke. The yoke and pole-plate structures are shaped to direct the magnetic flux appropriately. The outer surface of the pole plate is optimized subject to the minimization of a cost function, which evaluates the uniformity of the magnetic field over an ellipsoid. The magnetic field calculations required in this work are performed with the 3D finite element method software package Opera-3D. Each tentative design strategy is virtually modeled in this software package, which is externally controlled by MATLAB, with its key geometries defined as variables. The optimization variables are the thickness of the pole plate at control points distributed over the pole plate surface. A novel design concept as a superconducting non-axial magnet is introduced, which could create a large uniform B 0 magnetic field with fewer geometric restriction. This non-axial 0.5 T superconducting magnet has a moderately reduced SAD of 123 cm and a vertical patient opening of 68 cm. This work is presented as a proof of principle to investigate the feasibility of a non-axial magnet with the coils located around the yoke, and the results encourage future design optimizations to maximize the benefits of this non-axial design.

  11. Development of a silicon detector monitor for the HIE-ISOLDE superconducting upgrade of the REX-ISOLDE heavy-ion linac

    CERN Document Server

    Zocca, F; Bravin, E; Pasini, M; Voulot, D; Wenander, F

    2012-01-01

    A silicon detector monitor has been developed and tested in the framework of the beam diagnostics development program for the HIE-ISOLDE superconducting upgrade of the REX-ISOLDE heavy-ion linac at CERN. The monitor is intended for beam energy and timing measurements aimed at the phase tuning of the superconducting cavities. Tests were performed with a stable ion beam, composed of carbon, oxygen and neon ions accelerated to energies from 300keV/u to 2.82MeV/u. The energy measurements performed allowed for beam spectroscopy and ion identification with a resolution of 1.4%-0.5% rms in the measured energy range. The achieved resolution is suited for a fast phase tuning of the cavities, which was demonstrated with the third REX 7-gap resonator. The time structure of the beam, characterised by a bunch period of 9.87ns, was measured with a resolution better than 200ps rms. This paper describes the results from all these tests and provides details of the detector set-up.

  12. The ISS protontherapy LINAC

    Science.gov (United States)

    Picardi, L.; Ronsivalle, C.; Vignati, A.

    1997-02-01

    The TERA foundation stimulated in the past years a comparative study of compact proton accelerators for therapy and at the end of 1995 the Italian National Institute of Health (Istituto Superiore di Sanità, ISS) decided for the construction of a proton linac for its TOP (Terapia Oncologica con Protoni) project. The TOP-LINAC will be composed of a 7 MeV RFQ+DTL injector followed by a 7-65 MeV section of the innovative 3 GHz SCDTL structure and a 65-200 MeV variable energy SCL 3 GHz structure. A 5-cavity model of the SCDTL has been built and measured on a RF test bench while a 11-cavities prototype (accelerating until 12.5 MeV) is under construction and will be assembled within few months. The TOP LINAC whose construction will start at the end of 1996, will be the first linear accelerator dedicated to proton therapy, and the first 3 GHz proton linac. In this paper the accelerator design and the construction schedule will be presented, and the SCDTL structure RF measurements will be discussed.

  13. Superconductivity

    CERN Document Server

    Poole, Charles P; Farach, Horacio A

    1995-01-01

    Superconductivity covers the nature of the phenomenon of superconductivity. The book discusses the fundamental principles of superconductivity; the essential features of the superconducting state-the phenomena of zero resistance and perfect diamagnetism; and the properties of the various classes of superconductors, including the organics, the buckministerfullerenes, and the precursors to the cuprates. The text also describes superconductivity from the viewpoint of thermodynamics and provides expressions for the free energy; the Ginzburg-Landau and BCS theories; and the structures of the high

  14. LINAC 4

    CERN Multimedia

    2013-01-01

    On 13 March, a beam of negative hydrogen ions was injected into the first accelerator module of Linac 4, the linear accelerator which will replace Linac 2. The beam was created in the new source built for Linac 4 and accelerated from 45 kEV to 3 MeV by a radiofrequency quadrupole (RFQ) module, the first link in the Linac 4 accelerator chain. This crucial phase went off without a hitch. The video above shows the new Linac 4 ion source, the low-energy transfer line and the RFQ, with running commentary by Giulia Bellodi and Carlo Rossi from the Beams Department.

  15. UH-FLUX: Compact, Energy Efficient Superconducting Asymmetric Energy Recovery LINAC for Ultra-high Fluxes of X-ray and THz Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Konoplev, Ivan [Univ. of Oxford (United Kingdom). JAI, Dept. of Physics; Ainsworth, Robert [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Burt, Graeme [Lancaster Univ. (United Kingdom). Cockcroft Inst.; Seryi, Andrei [Univ. of Oxford (United Kingdom). JAI, Dept. of Physics

    2016-06-01

    The conventional ERLs have limited peak beam current because increasing the beam charge and repetition rate leads to appearance of the beam break-up instabilities. At this stage the highest current, from the SRF ERL, is around 300 mA. A single-turn (the beam will be transported through the accelerating section, interaction point and deceleration section of the AERL only once) Asymmetric Energy Recovery LINAC (AERL) is proposed. The RF cells in different sections of the cavity are tuned in such a way that only operating mode is uniform inside all of the cells. The AERL will drive the electron beams with typical energies of 10 - 30 MeV and peak currents above 1 A, enabling the generation of high flux UV/X-rays and high power coherent THz radiation. We aim to build a copper prototype of the RF cavity for a compact AERL to study its EM properties. The final goal is to build AERL based on the superconducting RF cavity. Preliminary design for AERL's cavity has been developed and will be presented. The results of numerical and analytical models and the next steps toward the AERL operation will also be discussed.

  16. UH-FLUX: Compact, Energy Efficient Superconducting Asymmetric Energy Recovery LINAC for Ultra-high Fluxes of X-ray and THz Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Konoplev, Ivan [JAI, UK; Ainsworth, Robert [Fermilab; Burt, Graeme [Lancaster U.; Seryi, Andrei [JAI, UK

    2016-06-01

    The conventional ERLs have limited peak beam current because increasing the beam charge and repetition rate leads to appearance of the beam break-up instabilities. At this stage the highest current, from the SRF ERL, is around 300 mA. A single turn (the beam will be transported through the accelerating section, interaction point and deceleration section of the AERL only once) Asymmetric Energy Recovery LINAC (AERL) is proposed. The RF cells in different sections of the cavity are tuned in such a way that only operating mode is uniform inside all of the cells. The AERL will drive the electron beams with typical energies of 10 - 30 MeV and peak currents above 1 A, enabling the generation of high flux UV/X-rays and high power coherent THz radiation. We aim to build a copper prototype of the RF cavity for a compact AERL to study its EM properties. The final goal is to build AERL based on the superconducting RF cavity. Preliminary design for AERL's cavity has been developed and will be presented. The results of numerical and analytical models and the next steps toward the AERL operation will also be discussed.

  17. Superconductivity

    CERN Document Server

    Thomas, D B

    1974-01-01

    A short general review is presented of the progress made in applied superconductivity as a result of work performed in connection with the high-energy physics program in Europe. The phenomenon of superconductivity and properties of superconductors of Types I and II are outlined. The main body of the paper deals with the development of niobium-titanium superconducting magnets and of radio-frequency superconducting cavities and accelerating structures. Examples of applications in and for high-energy physics experiments are given, including the large superconducting magnet for the Big European Bubble Chamber, prototype synchrotron magnets for the Super Proton Synchrotron, superconducting d.c. beam line magnets, and superconducting RF cavities for use in various laboratories. (0 refs).

  18. Superconductivity

    Science.gov (United States)

    1989-07-01

    SUPERCONDUCTIVITY HIGH-POWER APPLICATIONS Electric power generation/transmission Energy storage Acoustic projectors Weapon launchers Catapult Ship propulsion • • • Stabilized...temperature superconductive shields could be substantially enhanced by use of high-Tc materials. 27 28 NRAC SUPERCONDUCTIVITY SHIP PROPULSION APPLICATIONS...motor shown in the photograph. As a next step in the evolution of electric-drive ship propulsion technology, DTRC has proposed to scale up the design

  19. Superconductivity

    CERN Document Server

    Ketterson, John B

    2008-01-01

    Conceived as the definitive reference in a classic and important field of modern physics, this extensive and comprehensive handbook systematically reviews the basic physics, theory and recent advances in the field of superconductivity. Leading researchers, including Nobel laureates, describe the state-of-the-art in conventional and unconventional superconductors at a particularly opportune time, as new experimental techniques and field-theoretical methods have emerged. In addition to full-coverage of novel materials and underlying mechanisms, the handbook reflects continued intense research into electron-phone based superconductivity. Considerable attention is devoted to high-Tc superconductivity, novel superconductivity, including triplet pairing in the ruthenates, novel superconductors, such as heavy-Fermion metals and organic materials, and also granular superconductors. What’s more, several contributions address superconductors with impurities and nanostructured superconductors. Important new results on...

  20. LINAC4

    CERN Multimedia

    2017-01-01

    The film illustrates CERN’s new linear accelerator for negative hydrogen ions (H-) Linac4. The klystron hall is shown. In the linac4 tunnel: the H- source, the radiofrequency quadrupole (RFQ), Drift tube (DTL), CCDTL and Pi-mode accelerating structure are shown. The H- dump and transfer line gallery towards the PS-booster are shown. Eventually the bird’s eye view of the booster and PS ring accelerators are shown.

  1. Measurement of groove features and dimensions of the vertical test cathode and the choke joint of the superconducting electron gun cavity of the Energy Recovery LINAC

    Energy Technology Data Exchange (ETDEWEB)

    Hammons, L.; Ke, M.

    2011-10-13

    A testing program for the superconducting electron gun cavity that has been designed for the Energy Recovery LINAC is being planned. The goal of the testing program is to characterize the RF properties of the gun cavity at superconducting temperatures and, in particular, to study multipacting that is suspected to be occurring in the choke joint of the cavity where the vertical test cathode is inserted. The testing program will seek to understand the nature and cause of this multipacting and attempt to eliminate it, if possible, by supplying sufficient voltage to the cavity. These efforts are motivated by the multipacting issues that have been observed in the processing of the fine-grain niobium gun cavity. This cavity, which is being processed at Thomas Jefferson National Laboratory for Brookhaven, has encountered multipacting at a gradient of approximately 3 MV/m and, to date, has resisted efforts at elimination. Because of this problem, a testing program is being established here in C-AD that will use the large-grain niobium gun cavity that currently resides at Brookhaven and has been used for room-temperature measurements. The large-grain and fine-cavities are identical in every aspect of construction and only differ in niobium grain size. Thus, it is believed that testing and conditioning of the large-grain cavity should yield important insights about the fine-grain cavity. One element of this testing program involves characterizing the physical features of the choke joint of the cavity where the multipacting is believed to be occurring and, in particular the grooves of the joint. The configuration of the cavity and the vertical test cathode is shown in Figure 1. In addition, it is important to characterize the groove of the vertical test cathode. The grooved nature of these two components was specifically designed to prevent multipacting. However, it is suspected that, because of the chemical processing that the fine-grain gun cavity underwent along with the

  2. Design and Development of RF Structures for Linac4

    CERN Document Server

    Vretenar, M; Gerigk, F; Pasini, M; Wegner, R

    2006-01-01

    Linac4 is a new 160 MeV H− linac proposed at CERN to replace the 50 MeV Linac2 as injector to the PS Booster, with the goal of doubling its brightness and intensity. The present design foresees after RFQ and chopping line a sequence of three accelerating structures: a Drift Tube Linac (DTL) from 3 to 40 MeV, a Cell-Coupled DTL (CCDTL) to 90 MeV and a Side Coupled Linac (SCL) up to the final energy. The DTL and CCDTL operate at 352 MHz, while in the SCL the frequency is doubled to 704 MHz. Although the injection in the PS Booster requires only a low duty cycle, the accelerating structures are designed to operate at the high duty cycle required by a possible future extension to a high-power linac driver for a neutrino facility. This paper presents the different accelerating structures, underlining the progress in the design of critical resonator elements, like post-couplers in the DTL, coupling slots in the CCDTL and bridge couplers for the SCL. Prototyping progress for the different structures is reported...

  3. Superconductivity

    CERN Document Server

    Poole, Charles P; Creswick, Richard J; Prozorov, Ruslan

    2014-01-01

    Superconductivity, Third Edition is an encyclopedic treatment of all aspects of the subject, from classic materials to fullerenes. Emphasis is on balanced coverage, with a comprehensive reference list and significant graphics from all areas of the published literature. Widely used theoretical approaches are explained in detail. Topics of special interest include high temperature superconductors, spectroscopy, critical states, transport properties, and tunneling. This book covers the whole field of superconductivity from both the theoretical and the experimental point of view. This third edition features extensive revisions throughout, and new chapters on second critical field and iron based superconductors.

  4. Status of the TOP Linac project

    Energy Technology Data Exchange (ETDEWEB)

    Cianfarani, Cesidio [ENEA, Via E. Fermi 45, Frascati (Rome) (Italy); Cisbani, Evaristo [ISS, Viale Regina Elena 199, Rome (Italy); Orlandi, Gianluca [ENEA, Via E. Fermi 45, Frascati (Rome) (Italy); Frullani, Salvatore [ISS, Viale Regina Elena 199, Rome (Italy); Picardi, Luigi [ENEA, Via E. Fermi 45, Frascatim(Rome) (Italy)]. E-mail: picardi@frascati.enea.it; Concetta Ronsivalle [ENEA, Via E. Fermi 45, Frascati (Rome) (Italy)

    2006-06-23

    The TOP Linac (Oncological Therapy with Protons), under development by ENEA and ISS is a sequence of three pulsed (5 {mu}s 300 Hz) linear accelerators: a 7 MeV, 425 MHz RFQ+DTL (AccSys Model PL-7), a 7-65 MeV, 2998 MHz Side Coupled Drift Tube Linac (SCDTL) and a 65-200 MeV, variable energy 2998 MHz Side Coupled Linac (SCL). The status of the project will be presented. The 7 MeV injector is installed at ENEA-Frascati laboratories. The first SCDTL module structure, composed by nine DTL tanks coupled by eight side cavities, has been built and tested on RF bench, so that it is ready for proton acceleration. The results of the measurements done will be also shown.

  5. High Frequency Linacs for Hadrontherapy

    Science.gov (United States)

    Amaldi, Ugo; Braccini, Saverio; Puggioni, Paolo

    The use of radiofrequency linacs for hadrontherapy was proposed about 20 years ago, but only recently has it been understood that the high repetition rate together with the possibility of very rapid energy variations offers an optimal solution to the present challenge of hadrontherapy: "paint" a moving tumor target in three dimensions with a pencil beam. Moreover, the fact that the energy, and thus the particle range, can be electronically adjusted implies that no absorber-based energy selection system is needed, which, in the case of cyclotron-based centers, is the cause of material activation. On the other side, a linac consumes less power than a synchrotron. The first part of this article describes the main advantages of high frequency linacs in hadrontherapy, the early design studies, and the construction and test of the first high-gradient prototype which accelerated protons. The second part illustrates some technical issues relevant to the design of copper standing wave accelerators, the present developments, and two designs of linac-based proton and carbon ion facilities. Superconductive linacs are not discussed, since nanoampere currents are sufficient for therapy. In the last two sections, a comparison with circular accelerators and an overview of future projects are presented.

  6. R&D Energy Recovery Linac at Brookhaven National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Litvinenko, Vladimir; Beavis, D.; Ben-Zvi, Ilan; Blaskiewicz, Michael; Burrill, Andrew; Calaga, Rama; Cameron, Peter; Chang, Xiangyun; Drees, K.A.; Ganetis, G.; Gamble, Michael; Hahn, H.; Hammons, L.R.; Hershcovitch, A.; Hseuh, H.C.; Jain, A.K.; Kayran, A.; Kewisch, Jorg; Lambiase, R.F.; Lederle, D.L.; Mahler, G.J.; McIntyre, G.; Meng, W.; Nehring, T.C.; Oerter, B.; Pai, C.; Pate, D.; Phillips, Daniel; Pozdeyev, Eduard; Rao, Triveni; Reich, J.; Roser, Thomas; Russo, T.; Smith, K.; Tuozzolo, Joseph; Weiss, D.; Williams, N.W.W.; Yip, Kin; Zaltsman, A.; Bluem, Hans; Cole, Michael; Favale, Anthony; Holmes, D.; Rathke, John; Schultheiss, Tom; Delayen, Jean; Funk, L.; Phillips, H.; Preble, Joseph

    2008-07-01

    Collider Accelerator Department at BNL is in the final stages of developing the 20-MeV R&D energy recovery linac with super-conducting 2.5 MeV RF gun and single-mode super-conducting 5-cell RF linac. This unique facility aims to address many outstanding questions relevant for high current (up to 0.5 A of average current), high brightness energy-recovery linacs with novel Zigzag-type merger. We present the performance of the R&D ERL elements and detailed commissioning plan.

  7. Student-Centred Learning (SCL): Roles Changed?

    Science.gov (United States)

    Onurkan Aliusta, Gülen; Özer, Bekir

    2017-01-01

    This paper addresses the espoused and enacted practices of high school teachers with regard to student-centred learning (SCL). Explanatory mixed-method design, where quantitative strand is followed by qualitative one, is employed. While the quantitative strand aims to explore teachers' perceptions regarding the extent student-centred teacher and…

  8. Superconducting magnetic quadrupole

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.W.; Shepard, K.W.; Nolen, J.A.

    1995-08-01

    A design was developed for a 350 T/m, 2.6-cm clear aperture superconducting quadrupole focussing element for use in a very low q/m superconducting linac as discussed below. The quadrupole incorporates holmium pole tips, and a rectangular-section winding using standard commercially-available Nb-Ti wire. The magnet was modeled numerically using both 2D and 3D codes, as a basis for numerical ray tracing using the quadrupole as a linac element. Components for a prototype singlet are being procured during FY 1995.

  9. ILC Linac R&D at SLAC

    Energy Technology Data Exchange (ETDEWEB)

    Adolphsen, C.; /SLAC

    2006-08-09

    Since the ITRP recommendation in August 2004 to use superconducting rf technology for a next generation linear collider, the former NLC Group at SLAC has been actively pursuing a broad range of R&D for this collider (the ILC). In this paper, the programs concerning linac technology are reviewed. Current activities include the development of a Marx-style modulator and a 10 MW sheet-beam klystron, operation of an L-band (1.3 GHz) rf source using an SNS HVCM modulator and commercial klystrons, design of a more efficient and less costly rf distribution system, construction of a coupler component test stand, fabrication of a prototype positron capture cavity, beam tests of prototype S-band linac beam position monitors and preparations for magnetic center stability measurements of a prototype SC linac quad.

  10. LINAC4 Footage

    CERN Multimedia

    2017-01-01

    Geneva, 9 May 2017. At a ceremony today, CERN inaugurated its linear accelerator, Linac 4, the newest accelerator acquisition since the Large Hadron Collider (LHC). Linac 4 is due to feed the CERN accelerator complex with particle beams of higher energy, which will allow the LHC to reach higher luminosity by 2021. After an extensive testing period, Linac 4 will be connected to CERN’s accelerator complex during the upcoming long technical shut down in 2019-20. Linac 4 will replace Linac 2, which has been in service since 1978. It will become the first step in CERN’s accelerator chain, delivering proton beams to a wide range of experiments

  11. LINAC4 Footage (HD)

    CERN Multimedia

    2017-01-01

    Geneva, 9 May 2017. At a ceremony today, CERN inaugurated its linear accelerator, Linac 4, the newest accelerator acquisition since the Large Hadron Collider (LHC). Linac 4 is due to feed the CERN accelerator complex with particle beams of higher energy, which will allow the LHC to reach higher luminosity by 2021. After an extensive testing period, Linac 4 will be connected to CERN’s accelerator complex during the upcoming long technical shut down in 2019-20. Linac 4 will replace Linac 2, which has been in service since 1978. It will become the first step in CERN’s accelerator chain, delivering proton beams to a wide range of experiments

  12. Progress in the Development of the TOP Linac

    CERN Document Server

    Picardi, L

    2004-01-01

    The TOP Linac (Oncological Therapy with Protons), under development by ENEA and ISS is a sequence of three pulsed (5 msec, 300 Hz) linear accelerators: a 7 MeV, 425 MHz RFQ+DTL (AccSys Model PL-7), a 7–65 MeV, 2998 MHz Side Coupled Drift Tube Linac (SCDTL) and a 65–200 MeV, variable energy 2998 MHz Side Coupled Linac (SCL). The first SCDTL module is composed by 11 DTL tanks coupled by 10 side cavities. The tanks has modified to overcome vacuum leakage that occurred during brazing, and now the module has been completed, and is ready to be tested with protons. The 7 MeV injector has been recently installed in the ENEA Frascati laboratories for preliminary test, before being transferred to the main Oncologycal Hospital in Rome, Istituto Regina Elena.

  13. Development of RF linac for high-current applications

    Energy Technology Data Exchange (ETDEWEB)

    Chan, K.C.D.; Lawrence, G.P.; Schneider, J.D.

    1997-12-31

    High-current proton linacs are promising sources of neutrons for material processing and research applications. Recently, a linac design that makes use of a combination of normal-conducting (NC) and superconducting (SC) linac technologies has been proposed for the US Accelerator Production of Tritium Project. As a result, a multi-year engineering development and demonstration (ED and D) program is underway. In this paper, the authors will describe the design and merits of the NC/SC hybrid approach. The scope, technology issues, and present status of the ED and D Program, and the participation of industry will also be described.

  14. Development of an Eddy Current Septum for LINAC4

    CERN Document Server

    Barnes, M; Borburgh, J; Fowler, T; Goddard, B; Ueda, A; Weterings, W

    2008-01-01

    A linear accelerator (linac) is the first stage of the CERN accelerator complex. The linac defines the beam quality for subsequent stages of acceleration and the reliability has to be high as a fault of the linac shuts down all other machines. The existing linacs at CERN were designed 30 or more years ago: recent upgrades allowed the linacs to reach LHC requirements but also showed that they are at the limit of their brightness and intensity capabilities. A replacement Superconducting Proton Linac (SPL) has been proposed; the initial part of the SPL is termed LINAC4. The LINAC4 injection bump would be made up of a set of four pulsed dipole magnets; the first of these magnets (BS1) must act as a septum with a thin element dividing the high-field region of the circulating beam from the field-free region through which injected $H^{-}$ beam must pass. The initial specifications for BS1 required; a deflection of 66 mrad at 160 MeV, achieved with a peak field of 628 mT and a length of 250 mm: the field fall time wa...

  15. Linac 1, inner structure

    CERN Multimedia

    1968-01-01

    This photo shows the inner structure of Linac 1. As injector to the PS, and later to the Booster, Linac 1 accelerated protons to 50 MeV, but it has also accelerated heavier ions. Fitted with a 520 keV RFQ pre-injector (instead of the original Cockcroft-Walton generator), it delivered protons and heavy ions to LEAR, from 1982 to 1992. After 33 years of faithful service, Linac 1 was dismantled in 1992 to make room for Linac 3 (Pb ions).

  16. Psychometric validation of the Hopkins Symptom Checklist (SCL-90) subscales for depression, anxiety, and interpersonal sensitivity

    DEFF Research Database (Denmark)

    Bech, P; Bille, J; Møller, S B

    2014-01-01

    BACKGROUND: The psychometric validity of many subscales of the 90-item Hopkins Symptom Checklist (SCL-90) remains largely unknown. Therefore, the aim of the present study was to evaluate the psychometric properties of the "Hamilton-subscales" for depression (SCL-D16), anxiety (SCL-A14), their 6......-item core-measures (SCL-D6 and SCL-A6), the anxiety symptom scale (SCL-ASS8) and the interpersonal sensitivity scale (IPS5). METHODS: The psychometric properties of the SCL-D16, SCL-A14, SCL-D6, SCL-A6, SCL-ASS8, and the IPS5 were evaluated based on SCL-90 ratings from 850 day patients from a Danish...... SCL-90 subscales were identified. Using these scales it is possible to perform a psychometrically valid evaluation of psychiatric patients regarding the severity of depression (HAM-D6), specific anxiety (SCL-ASS8) and interpersonal sensitivity (IPS5)....

  17. Linac pre-injector

    CERN Multimedia

    1965-01-01

    New accelerating column of the linac pre-injector, supporting frame and pumping system. This new system uses two mercury diffusion pumps (in the centre) and forms part of the modifications intended to increase the intensity of the linac. View taken during assembly in the workshop.

  18. Alignment and Field Error Tolerance in Linac4

    CERN Document Server

    Bellodi, G; Garcia Tudela, M; Hein, L; Lallement, J B; Lanzone, S; Lombardi, A M; Posocco, P; Sargsyan, E

    2011-01-01

    LINAC4 [1] is a linear accelerator for negative Hydrogen ions (H−), which will replace the 50 MeV proton LINAC (LINAC2) as linear injector for the CERN accelerators. The higher output energy (160 MeV) together with charge-exchange injection will allow increasing beam intensity in the following machines. LINAC4 is about 80 m long, normal-conducting, and will be housed in a tunnel 12 m below ground on the CERN Meyrin site. The location has been chosen to allow using LINAC4 as the first stage of acceleration for a Multi-MegaWatt superconducting LINAC (SPL [2]). A 60 m long transfer line brings the beam towards the present LINAC2-to-PS Booster transfer line, which is joined at the position of BHZ20. The new transfer line consists of 17 new quadrupoles, an RF cavity and 4 bending magnets to adjust both the direction and the level for injection into the PS Booster. End-to-end beam dynamics simulations have been carried out in parallel with the codes PATH [3] and TRACEWIN[4]. Following the definition of the layout...

  19. Compendium of Scientific Linacs

    Energy Technology Data Exchange (ETDEWEB)

    Clendenin, James E

    2003-05-16

    The International Committee supported the proposal of the Chairman of the XVIII International Linac Conference to issue a new Compendium of linear accelerators. The last one was published in 1976. The Local Organizing Committee of Linac96 decided to set up a sub-committee for this purpose. Contrary to the catalogues of the High Energy Accelerators which compile accelerators with energies above 1 GeV, we have not defined a specific limit in energy. Microtrons and cyclotrons are not in this compendium. Also data from thousands of medical and industrial linacs has not been collected. Therefore, only scientific linacs are listed in the present compendium. Each linac found in this research and involved in a physics context was considered. It could be used, for example, either as an injector for high energy accelerators, or in nuclear physics, materials physics, free electron lasers or synchrotron light machines. Linear accelerators are developed in three continents only: America, Asia, and Europe. This geographical distribution is kept as a basis. The compendium contains the parameters and status of scientific linacs. Most of these linacs are operational. However, many facilities under construction or design studies are also included. A special mention has been made at the end for the studies of future linear colliders.

  20. Wake Field Effects in the APT Linac.

    Science.gov (United States)

    Kurennoy, Sergey

    1998-04-01

    The 1.7-GeV 100-mA CW proton linac is now under design for the Accelerator Production of Tritium (APT) Project. While wake-field effects are usually considered negligible in proton linacs, an analysis for the APT accelerator has been performed to exclude potential problems at such a high current leading to beam losses. Loss factors and resonance frequency spectra of various discontinuities of the vacuum chamber are investigated, both analytically and using 2-D and 3-D simulation codes with a single bunch as well as with many bunches. The only noticeable effect is the HOM heating of the 5-cell superconducting cavities. However, it has an acceptable level and will be further reduced by HOM couplers.

  1. Brookhaven Linac Isotope Producer

    Data.gov (United States)

    Federal Laboratory Consortium — The Brookhaven Linac Isoptope Producer (BLIP)—positioned at the forefront of research into radioisotopes used in cancer treatment and diagnosis—produces commercially...

  2. Deliverable D3 - Low- and Medium-beta linac

    CERN Document Server

    A. Facco, A. Balabin, R. Paparella, D. Zenere, INFN-Laboratori Nazionali di Legnaro, Padova, Italy; D. Berkovits, J. Rodnizki, SOREQ, Yavne, Israel; J. L. Biarrotte, S. Bousson, A. Ponton, G. Olry, IPN Orsay, France; R. Duperrier, D. Uriot, CEA/Saclay, France; V. Zvyagintsev, TRIUMF, Vancouver, Canada.

    The present document describes the Low- and Medium-beta section of the EURISOL DS Driver Accelerator. This section consists of a superconducting linac, based on Half-Wave (HWR) and SPOKE type resonators, preceded by a short, normal-conducting MEBT (Medium Energy Beam Transport) section that performs input beam matching. The scope of this linac is to bring the beams of H-, D+ and 3He++ produced by the Ion Injector (Deliverable D-5) to the energy and beam parameters required for injection in the superconducting High-beta linac (Deliverable D4-High beta linac). The present beam dynamics design reaches the goal of accelerating the required high current beams to the design energy (about 100 MeV/A, depending on the ion species), with minimum emittance growth and with low losses, using realistic and cost-effective, although innovative, technological solutions. The Low- and Medium-beta linac layout is described, together with the fundamental parameters and characteristics of its components and the system performanc...

  3. Deliverable D3 - Low- and Medium-beta linac

    CERN Document Server

    A. Facco, A. Balabin, R. Paparella, D. Zenere, INFN-Laboratori Nazionali di Legnaro, Padova, Italy; D. Berkovits, J. Rodnizki, SOREQ, Yavne, Israel; J. L. Biarrotte, S. Bousson, A. Ponton, G. Olry, IPN Orsay, France; R. Duperrier, D. Uriot, CEA/Saclay, France; V. Zvyagintsev, TRIUMF, Vancouver, Canada.

    The present document describes the Low- and Medium-beta section of the EURISOL DS Driver Accelerator. This section consists of a superconducting linac, based on Half-Wave (HWR) and SPOKE type resonators, preceded by a short, normal-conducting MEBT (Medium Energy Beam Transport) section that performs input beam matching. The scope of this linac is to bring the beams of H-, D+ and 3He++ produced by the Ion Injector (Deliverable D-5) to the energy and beam parameters required for injection in the superconducting High-beta linac (Deliverable D4-High beta linac). The present beam dynamics design reaches the goal of accelerating the required high current beams to the design energy (about 100 MeV/A, depending on the ion species), with minimum emittance growth and with low losses, using realistic and cost-effective, although innovative, technological solutions. The Low- and Medium-beta linac layout is described, together with the fundamental parameters and characteristics of its components and the system performance.

  4. High-Power Proton Linac Technology at CERN

    Science.gov (United States)

    Gerigk, Frank

    The construction of Linac4, a 160 MeV H- linac started in 2008 and is now in the beam commissioning phase. The RFQ and MEBT line have been successfully commissioned; and installation and beam measurements of the 50 MeV DTL have started in 2014. Linac4 was conceived as the normal conducting front-end for a Superconducting Proton Linac (SPL), providing 5 GeV protons for a future neutrino facility at CERN. In the last 2 years the CERN infrastructure for the construction, surface treatment and testing of superconducting cavities has been upgraded to be compatible with the prototyping of a 4-cavity SPL type cryomodule. The 704 MHz 5-cell Niobium cavities, presently being built and tested at CERN are of interest also for other potential future projects at CERN and therefore the SPL R&D effort is well supported over the coming years. This paper reviews the context and status of Linac4 and SPL and highlights some of the technological developments, which have been done at CERN and which are foreseen within the next years.

  5. Source Couple Logic (SCL: Theory and Physical Design

    Directory of Open Access Journals (Sweden)

    Mohamed Azaga

    2008-01-01

    Full Text Available This study describes and presents the analysis for the Source-Coupled Logic (SCL inverter as will as the effect of submicron layout parasitics. The SCL inverter circuit model and its operation is defined. The analysis for the SCL is carried from the point of view of input/output voltage characteristics and the effect of noise margin. The inverter gate delay model is described and the effect of biasing current on the delay is shown. The result shows that, the delay of the SCL inverter is decreased as biasing current increase. The simulation is done based on the 0.18 µ Silterra PDK. Different layouts for SCL inverter have been investigated for its effect on output voltage swing, switching noise and the area. The results show an important effect on the SCL output signals. Post-Simulation was carried out on all proposed layouts using HSPICE and using 0.35 µ­ MIMOS Berhad PDK. The layout was done using Virtuous from Cadence where as the extraction done using Mentor Graphic-Caliber Interactive tool.

  6. Beam dynamics studies of the HIE-LINAC at CERN

    CERN Document Server

    Fraser, MA

    2008-01-01

    We present a beam dynamics study of the superconducting (SC) HIE-LINAC proposed to replace the existing normal conducting REX-ISOLDE accelerating infrastructure at CERN. The Linear Accelerator Numerical Analysis (LANA) code was used to run first-order simulations of the HIE-LINAC in order to study the beam quality during acceleration. A resonance in the transverse emittance growth at ejection from the HIE-LINAC was discovered and understood as a parametric coupling between the longitudinal and transverse dynamics. The dangerous effect of this resonance can be avoided for all mass-to-charge states in the range 2.5 ≤ A/q ≤ 4.5, if the linac is operated with a transverse phase advance higher than 70 degrees. The transverse emittance growth is minimised along the HIE-LINAC if operated above a transverse phase advance of 90 degrees per focusing period. Without a dedicated matching region between the two sections of the HIE-LINAC a solution for matching the beam was found by using the solenoids in the low-energ...

  7. Wake field effect analysis in APT linac

    Energy Technology Data Exchange (ETDEWEB)

    Kurennoy, S.S.

    1998-12-31

    The 1.7-GeV 100-mA CW proton linac is now under design for the Accelerator Production of Tritium (APT) Project. The APT linac comprises both the normal conducting (below 211 MeV) and superconducting (SC) sections. The high current leads to stringent restrictions on allowable beam losses (< 1 nA/m), that requires analyzing carefully all possible loss sources. While wake-field effects are usually considered negligible in proton linacs, the authors study these effects for the APT to exclude potential problems at such a high current. Loss factors and resonance frequency spectra of various discontinuities of the vacuum chamber are investigated, both analytically and using 2-D and 3-D simulation codes with a single bunch as well as with many bunches. The main conclusion is that the only noticeable effect is the HOM heating of the 5-cell SC cavities. It, however, has an acceptable level and, in addition, will be taken care of by HOM couplers.

  8. Wake Field Effect Analysis in APT Linac

    CERN Document Server

    Kurennoy, S S

    1998-01-01

    The 1.7-GeV 100-mA CW proton linac is now under design for the Accelerator Production of Tritium (APT) Project. The APT linac comprises both the normal conducting (below 211 MeV) and superconducting (SC) sections. The high current leads to stringent restrictions on allowable beam losses (<1 nA/m), that requires analyzing carefully all possible loss sources. While wake-field effects are usually considered negligible in proton linacs, we study these effects for the APT to exclude potential problems at such a high current. Loss factors and resonance frequency spectra of various discontinuities of the vacuum chamber are investigated, both analytically and using 2-D and 3-D simulation codes with a single bunch as well as with many bunches. Our main conclusion is that the only noticeable effect is the HOM heating of the 5-cell SC cavities. It, however, has an acceptable level and, in addition, will be taken care of by HOM couplers.

  9. Progress in Induction Linacs

    Energy Technology Data Exchange (ETDEWEB)

    Caporaso, G J

    2000-09-27

    This presentation will be a broad survey of progress in induction technology over the past four years. Much work has been done on accelerators for hydrodynamic test radiography and other applications. Solid-state pulsers have been developed which can provide unprecedented flexibility and precision in pulse format and accelerating voltage for both ion and electron induction machines. Induction linacs can now be built which can operate with MHz repetition rates. Solid-state technology has also made possible the development of fast kickers for precision control of high current beams. New insulator technology has been developed which will improve conventional induction linacs in addition to enabling a new class of high gradient induction linacs.

  10. Conceptual study of high power proton linac for accelerator driven subcritical nuclear power system

    CERN Document Server

    Yu Qi; Ouyang Hua Fu; Xu Tao Guang

    2001-01-01

    As a prior option of the next generation of energy source, the accelerator driven subcritical nuclear power system (ADS) can use efficiently the uranium and thorium resource, transmute the high-level long-lived radioactive wastes and raise nuclear safety. The ADS accelerator should provide the proton beam with tens megawatts. The superconducting linac is a good selection of ADS accelerator because of its high efficiency and low beam loss rate. The ADS accelerator presented by the consists of a 5 MeV radio-frequency quadrupole, a 100 MeV independently phased superconducting cavity linac and a 1 GeV elliptical superconducting cavity linac. The accelerating structures and main parameters are determined and the research and development plan is considered

  11. Drift tubes of Linac 2

    CERN Multimedia

    1977-01-01

    With the advent of the 800 MeV PS Booster in 1972, the original injector of the PS, a 50 MeV Alvarez-type proton linac, had reached its limits, in terms of intensity and stability. In 1973 one therefore decided to build a new linac (Linac 2), also with a drift-tube Alvarez structure and an energy of 50 MeV. It had a new Cockcroft-Walton preinjector with 750 keV, instead of the previous one with 500 keV. Linac 2 was put into service in 1980. The old Linac 1 was then used for the study of, and later operation with, various types of ions. This picture shows Linac 2 drift-tubes, suspended on stems coming from the top, in contrast to Linac 1, where the drift-tubes stood on stems coming from the bottom.

  12. Recirculated and Energy Recovered Linacs

    Energy Technology Data Exchange (ETDEWEB)

    Geoffrey Krafft

    2003-05-01

    Linacs that are recirculated share many characteristics with ordinary linacs, including the ability to accelerate electron beams from an injector to high energy with relatively little (normalized) emittance growth and the ability to deliver ultrashort bunch duration pulses to users. When such linacs are energy recovered, the additional possibility of accelerating very high average beam current arises. Because this combination of beam properties is not possible from either a conventional linac, or from storage rings where emittance and pulse length are set by the equilibrium between radiation damping and quantum excitation of oscillations about the closed orbit, energy recovered linacs are being considered for an increasing variety of applications. These possibilities extend from high power free-electron lasers and recirculated linac light sources, to electron coolers for high energy colliders or actual electron-ion colliding- beam machines based on an energy recovered linac for the electrons.

  13. Recirculated and Energy Recovered Linacs

    CERN Document Server

    Geoffr-Ey-Kraff

    2003-01-01

    Linacs that are recirculated share many characteristics with ordinary linacs, including the ability to accelerate electron beams FR-om an injector to high energy with relatively little (normalized) emittance growth and the ability to deliver ultrashort bunch duration pulses to users. When such linacs are energy recovered, the additional possibility of accelerating very high average beam current arises. Because this combination of beam properties is not possible FR-om either a conventional linac, or FR-om storage rings where emittance and pulse length are set by the equilibrium between radiation damping and quantum excitation of oscillations about the closed orbit, energy recovered linacs are being considered for an increasing variety of applications. These possibilities extend FR-om high power FR-ee-electron lasers and recirculated linac light sources, to electron coolers for high energy colliders or actual electron-ion colliding- beam machines based on an energy recovered linac for the electrons.

  14. Coherent Effects of High Current Beam in Project-X Linac

    Energy Technology Data Exchange (ETDEWEB)

    Sukhanov, Alexander; Yakovlev, Vyacheslav; Gonin, Ivan; Khabiboulline, Timergali; Lunin, Andrei; Saini, Arun; Solyak, Nikolay; Vostrikov, Alexander

    2013-04-01

    Resonance excitation of longitudinal high order modes in superconducting RF structures of Project-X continuous wave linac is studied. We analyze regimes of operation of the linac with high beam current, which can be used to provide an intense muon source for the future Neutrino Factory or Muon Collider, and also important for the Accelerator-Driven Subcritical systems. We calculate power loss and associated heat load to the cryogenic system. Longitudinal emittance growth is estimated. We consider an alternative design of the elliptical cavity for the high energy part of the linac, which is more suitable for high current operation.

  15. Accelerators for hadrontherapy: From Lawrence cyclotrons to linacs

    Science.gov (United States)

    Amaldi, U.; Bonomi, R.; Braccini, S.; Crescenti, M.; Degiovanni, A.; Garlasché, M.; Garonna, A.; Magrin, G.; Mellace, C.; Pearce, P.; Pittà, G.; Puggioni, P.; Rosso, E.; Verdú Andrés, S.; Wegner, R.; Weiss, M.; Zennaro, R.

    2010-08-01

    Hadrontherapy with protons and carbon ions is a fast developing methodology in radiation oncology. The accelerators used and planned for this purpose are reviewed starting from the cyclotrons used in the thirties. As discussed in the first part of this paper, normal and superconducting cyclotrons are still employed, together with synchrotrons, for proton therapy while for carbon ion therapy synchrotrons have been till now the only option. The latest developments concern a superconducting cyclotron for carbon ion therapy, fast-cycling high frequency linacs and 'single room' proton therapy facilities. These issues are discussed in the second part of the paper by underlining the present challenges, in particular the treatment of moving organs.

  16. Heavy-ion LINAC development for the US RIA project

    Indian Academy of Sciences (India)

    P N Ostroumov

    2002-12-01

    The Nuclear Science Community in the Unites States has unanimously concluded that developments in both nuclear science and its supporting technologies make building a world-leading Rare-Isotope Accelerator (RIA) facility for production of radioactive beams the top priority. The RIA development effort involves several US Laboratories (ANL, JLAB, LBNL, MSU, ORNL). The RIA facility includes a CW 1.4 GeV driver LINAC and a 100 MV post-accelerator both based on superconducting (SC) cavities operating at frequencies from 48 MHz to 805 MHz. An initial acceleration in both LINACs is provided by room temperature RFQs. The driver LINAC is designed for acceleration of any ion species; from protons up to 900 MeV to uranium up to 400 MeV/u. The novel feature of the driver LINAC is an acceleration of multiple charge-state heavy-ion beams in order to achieve 400 kW beam power. Basic design concepts of the driver LINAC are given. Several new conceptual solutions in beam dynamics, room temperature and SC accelerating structures for heavy ion accelerator applications are discussed.

  17. Multiple-linac approach for tritium production and other applications

    Energy Technology Data Exchange (ETDEWEB)

    Ruggiero, A.G.

    1995-01-10

    This report describes an approach to tritium production based on the use of multiple proton linear accelerators. Features of a single APTT Linac as proposed by the Los Alamos National Laboratory are presented and discussed. An alternative approach to the attainment of the same total proton beam power of 200 MW with several lower-performance superconducting Linacs is proposed and discussed. Although each of these accelerators are considerable extrapolations of present technology, the latter can nevertheless be built at less technical risk when compared to the single high-current APT Linac, particularly concerning the design and the performance of the low-energy front-end. The use of superconducting cavities is also proposed as a way of optimizing the accelerating gradient, the overall length, and the operational costs. The superconducting technology has already been successfully demonstrated in a number of large-size projects and should be seriously considered for the acceleration of intense low-energy beams of protons. Finally, each linear accelerator would represent an ideal source of very intense beams of protons for a variety of applications, such as: weapons and waste actinide transmutation processes, isotopes for medical application, spallation neutron sources, and the generation of intense beams of neutrinos and muons for nuclear and high-energy physics research. The research community at large has obviously an interest in providing expertise for, and in having access to, the demonstration, the construction, the operation, and the exploitation of these top-performance accelerators.

  18. Beam Loss in Linacs

    CERN Document Server

    Plum, M A

    2016-01-01

    Beam loss is a critical issue in high-intensity accelerators, and much effort is expended during both the design and operation phases to minimize the loss and to keep it to manageable levels. As new accelerators become ever more powerful, beam loss becomes even more critical. Linacs for H- ion beams, such as the one at the Oak Ridge Spallation Neutron Source, have many more loss mechanisms compared to H+ (proton) linacs, such as the one being designed for the European Spallation Neutron Source. Interesting H- beam loss mechanisms include residual gas stripping, H+ capture and acceleration, field stripping, black-body radiation and the recently discovered intra-beam stripping mechanism. Beam halo formation, and ion source or RF turn on/off transients, are examples of beam loss mechanisms that are common for both H+ and H- accelerators. Machine protection systems play an important role in limiting the beam loss.

  19. Linacs for Medical Isotope Production

    Directory of Open Access Journals (Sweden)

    A. Pramudita

    2011-04-01

    Full Text Available This paper reviews efforts on using high energy (25-30 MeV and high power (10-20 kW electron linacs and lower energy (7 MeV proton linacs for medical radioisotope production. Using high energy x-rays from the electron linacs, PET (Positron Emission Tomography radioisotopes are produced through photonuclear reactions such as 19F(γ,n18F, which also allow production of other PET radionuclides 11C, 13N, and 15O. Other mostly used medical radionuclides 99mTc can also be obtained by using the electron linacs, through photofission or photonuclear reactions. Proton linacs for PET have also been recently developed and the product has been available in the market since 2005. The linacs have been tested for 18F production. As a proton accelerator, the target systems and nuclear reactions are similar to the ones used in PET cyclotrons

  20. Energy Recovery Linacs for Light Source Applications

    Energy Technology Data Exchange (ETDEWEB)

    George Neil

    2011-04-01

    Energy Recovery Linacs are being considered for applications in present and future light sources. ERLs take advantage of the continuous operation of superconducting rf cavities to accelerate high average current beams with low losses. The electrons can be directed through bends, undulators, and wigglers for high brightness x ray production. They are then decelerated to low energy, recovering power so as to minimize the required rf drive and electrical draw. When this approach is coupled with advanced continuous wave injectors, very high power, ultra-short electron pulse trains of very high brightness can be achieved. This paper will review the status of worldwide programs and discuss the technology challenges to provide such beams for photon production.

  1. FRIB driver linac vacuum model and benchmarks

    CERN Document Server

    Durickovic, Bojan; Kersevan, Roberto; Machicoane, Guillaume

    2014-01-01

    The Facility for Rare Isotope Beams (FRIB) is a superconducting heavy-ion linear accelerator that is to produce rare isotopes far from stability for low energy nuclear science. In order to achieve this, its driver linac needs to achieve a very high beam current (up to 400 kW beam power), and this requirement makes vacuum levels of critical importance. Vacuum calculations have been carried out to verify that the vacuum system design meets the requirements. The modeling procedure was benchmarked by comparing models of an existing facility against measurements. In this paper, we present an overview of the methods used for FRIB vacuum calculations and simulation results for some interesting sections of the accelerator. (C) 2013 Elsevier Ltd. All rights reserved.

  2. Superconducting linear accelerator system for NSC

    Indian Academy of Sciences (India)

    P N Prakash; T S Datta; B P Ajith Kumar; J Antony; P Barua; J Chacko; A Choudhury; G K Chadhari; S Ghosh; S Kar; S A Krishnan; Manoj Kumar; Rajesh Kumar; A Mandal; D S Mathuria; R S Meena; R Mehta; K K Mistri; A Pandey; M V Suresh Babu; B K Sahu; A Sarkar; S S K Sonti; A Rai; S Venkatramanan; J Zacharias; R K Bhowmik; A Roy

    2002-11-01

    This paper reports the construction of a superconducting linear accelerator as a booster to the 15 UD Pelletron accelerator at Nuclear Science Centre, New Delhi. The LINAC will use superconducting niobium quarter wave resonators as the accelerating element. Construction of the linear accelerator has progressed sufficiently. Details of the entire accelerator system including the cryogenics facility, RF electronics development, facilities for fabricating niobium resonators indigenously, and present status of the project are presented.

  3. Compact LINAC for deuterons

    Energy Technology Data Exchange (ETDEWEB)

    Kurennoy, S S [Los Alamos National Laboratory; O' Hara, J F [Los Alamos National Laboratory; Rybarcyk, L J [Los Alamos National Laboratory

    2008-01-01

    We are developing a compact deuteron-beam accelerator up to the deuteron energy of a few MeV based on room-temperature inter-digital H-mode (IH) accelerating structures with the transverse beam focusing using permanent-magnet quadrupoles (PMQ). Combining electromagnetic 3-D modeling with beam dynamics simulations and thermal-stress analysis, we show that IHPMQ structures provide very efficient and practical accelerators for light-ion beams of considerable currents at the beam velocities around a few percent of the speed of light. IH-structures with PMQ focusing following a short RFQ can also be beneficial in the front end of ion linacs.

  4. Energy Recovery Linacs

    Energy Technology Data Exchange (ETDEWEB)

    Nikolitsa Merminga

    2007-06-01

    The success and continuing progress of the three operating FELs based on Energy Recovery Linacs (ERLs), the Jefferson Lab IR FEL Upgrade, the Japan Atomic Energy Agency (JAEA) FEL, and the Novosibirsk High Power THz FEL, have inspired multiple future applications of ERLs, which include higher power FELs, synchrotron radiation sources, electron cooling devices, and high luminosity electron-ion colliders. The benefits of using ERLs for these applications are presented. The key accelerator physics and technology challenges of realizing future ERL designs, and recent developments towards resolving these challenges are reviewed.

  5. Fermilab drift tube Linac revisited

    Energy Technology Data Exchange (ETDEWEB)

    Milorad Popovic

    2004-05-12

    Using the PARMILA code running under PC-WINDOWS, the present performance of the Fermilab Drift Tube Linac has been analyzed in the light of new demands on the Linac/Booster complex (the Proton Source). The Fermilab Drift Tube Linac (DTL) was designed in the sixties as a proton linac with a final energy of 200 MeV and a peak current of 100mA. In the seventies, in order to enable multi-turn charge exchange injection into the Booster, the ion source was replaced by an H- source with a peak beam current of 25mA. Since then the peak beam current was steadily increased up to 55mA. In the early nineties, part of the drift tube structure was replaced with a side-coupled cavity structure in order to increase the final energy to 400 MeV. The original and still primary purpose of the linac is to serve as the injector for the Booster. As an added benefit, the Neutron Therapy Facility (NTF) was built in the middle seventies. It uses 66MeV protons from the Linac to produce neutrons for medical purposes. The Linac/Booster complex was designed to run at a fundamental cycling rate of 15Hz, but beam is accelerated on every cycle only when NTF is running. Until recently the demand from the High Energy Physics program resulted in an average linac beam repetition rate of order 1 Hz. With the MiniBoone experiment and the NuMI program, the demands on the Proton Source have changed, with emphasis on higher beam repetition rates up to 7.5Hz. Historically the beam losses in the linac were small, localized at one spot, so activation was not an important issue. With higher beam rate, this has the potential to become the dominant issue. Until today all tuning in the linac and Proton Source was governed by two goals: to maximize the peak beam current out of the linac and to minimize the beam losses in the linac. If maximal peak current from the linac is no longer a primary goal, then the linac quadrupoles can be adjusted differently to achieve different goals.

  6. Superconducting rf development at ATLAS

    Energy Technology Data Exchange (ETDEWEB)

    Shepard, K.W.; Kedzie, M.; Clifft, B.E. [Argonne National Lab., IL (United States); Roy, A.; Potukuchi, P. [Nuclear Science Centre, New Delhi (India); Givens, J.; Potter, J.; Crandall, K. [AccSys Technology, Inc., Pleasanton, CA (United States); Added, N. [Sao Paulo Univ., SP (Brazil)

    1993-12-31

    The ATLAS superconducting heavy-ion linac began operation in 1978 and has operated nearly continuously since that time, while undergoing a series of upgrades and expansions, the most recent being the ``uranium upgrade`` completed earlier this year and described below. In its present configuration the ATLAS linac consists of an array of 64 resonant cavities operating from 48 to 145 MHz, which match a range of particle velocities .007 < {beta} = v/c < .2. The linac provides approximately 50 MV of effective accelerating potential for ions of q/m > 1/10 over the entire periodic table. Delivered beams include 5 {minus} 7 pnA of {sup 238}U{sup 39+} at 1535 MeV. At present more than 10{sup 6} cavity-hours of operation at surface electric fields of 15 MV/m have been accumulated. Superconducting structure development at ATLAS is aimed at improving the cost/performance of existing low velocity structures both for possible future ATLAS upgrades, and also for heavy-ion linacs at other institutions. An application of particular current interest is to develop structures suitable for accelerating radioactive ion beams. Such structures must accelerate very low charge to mass ratio beams and must also have very large transverse acceptance.

  7. Construction Status of Linac4

    CERN Document Server

    Gerigk, F; Garoby, R; Hanke, K; Lombardi, A M; MacCaferri, R; Maury, S; Rossi, C; Vretenar, M

    2010-01-01

    The civil engineering works of the Linac4 linear accelerator at CERN started in October 2008 and regular machine operation is foreseen for 2013. Linac4 will accelerate H−ions to an energy of 160 MeV for injection into the PS Booster (PSB). It will thus replace the ageing Linac2, which presently injects at 50 MeV into the PSB, and it will also represents the first step in the injector upgrade for the LHC aiming at increasing its luminosity. This paper reports on the status of the design and construction of the main machine elements, which will be installed in the linac tunnel from the beginning of 2012 onwards, on the progress of the civil engineering and on the ongoing activities at the Linac4 test stand.

  8. Early endocardial morphogenesis requires Scl/Tal1.

    Directory of Open Access Journals (Sweden)

    Jeroen Bussmann

    2007-08-01

    Full Text Available The primitive heart tube is composed of an outer myocardial and an inner endocardial layer that will give rise to the cardiac valves and septa. Specification and differentiation of these two cell layers are among the earliest events in heart development, but the embryonic origins and genetic regulation of early endocardial development remain largely undefined. We have analyzed early endocardial development in the zebrafish using time-lapse confocal microscopy and show that the endocardium seems to originate from a region in the lateral plate mesoderm that will give rise to hematopoietic cells of the primitive myeloid lineage. Endocardial precursors appear to rapidly migrate to the site of heart tube formation, where they arrive prior to the bilateral myocardial primordia. Analysis of a newly discovered zebrafish Scl/Tal1 mutant showed an additional and previously undescribed role of this transcription factor during the development of the endocardium. In Scl/Tal1 mutant embryos, endocardial precursors are specified, but migration is severely defective and endocardial cells aggregate at the ventricular pole of the heart. We further show that the initial fusion of the bilateral myocardial precursor populations occurs independently of the endocardium and tal1 function. Our results suggest early separation of the two components of the primitive heart tube and imply Scl/Tal1 as an indispensable component of the molecular hierarchy that controls endocardium morphogenesis.

  9. Early endocardial morphogenesis requires Scl/Tal1.

    Science.gov (United States)

    Bussmann, Jeroen; Bakkers, Jeroen; Schulte-Merker, Stefan

    2007-08-01

    The primitive heart tube is composed of an outer myocardial and an inner endocardial layer that will give rise to the cardiac valves and septa. Specification and differentiation of these two cell layers are among the earliest events in heart development, but the embryonic origins and genetic regulation of early endocardial development remain largely undefined. We have analyzed early endocardial development in the zebrafish using time-lapse confocal microscopy and show that the endocardium seems to originate from a region in the lateral plate mesoderm that will give rise to hematopoietic cells of the primitive myeloid lineage. Endocardial precursors appear to rapidly migrate to the site of heart tube formation, where they arrive prior to the bilateral myocardial primordia. Analysis of a newly discovered zebrafish Scl/Tal1 mutant showed an additional and previously undescribed role of this transcription factor during the development of the endocardium. In Scl/Tal1 mutant embryos, endocardial precursors are specified, but migration is severely defective and endocardial cells aggregate at the ventricular pole of the heart. We further show that the initial fusion of the bilateral myocardial precursor populations occurs independently of the endocardium and tal1 function. Our results suggest early separation of the two components of the primitive heart tube and imply Scl/Tal1 as an indispensable component of the molecular hierarchy that controls endocardium morphogenesis.

  10. Design of the SNS Normal Conducting Linac RF Control System

    CERN Document Server

    Regan, A; Rohlev, T S; Wang, Y M; Prokop, M S; Thomson, D W; Regan, Amy; Kwon, Sung-il; Rohlev, Tony S.; Wang, Yi-Ming; Prokop, Mark S.; Thomson, David W.

    2000-01-01

    The Spallation Neutron Source (SNS) is being designed for operation in 2004. The SNS is a 1 GeV machine consisting of a combination normal-conducting and super-conducting linac as well as a ring and target area. The linac front end is a 402.5 MHz RFQ being developed by Lawrence Berkeley Lab. The DTL (at 402.5 MHz) and the CCL (at 805 MHz) stages are being developed by Los Alamos National Laboratory. The expected output energy of the DTL is 87 MeV and that of the CCL is 185 MeV. The RF control system under development for the linac is based on the Low Energy Demonstration Accelerator (LEDA) control system with some new features. This paper will discuss the new design approach and its benefits. Block diagrams and circuit specifics will be addressed. The normal conducting RF control system will be described in detail with references to the super-conducting control system where appropriate.

  11. Optimization of SRF Linacs

    Energy Technology Data Exchange (ETDEWEB)

    Powers, Tom [JLAB

    2013-09-01

    This work describes preliminary results of a new software tool that allows one to vary parameters and understand the effects on the optimized costs of construction plus 10 year operations of an SRF linac, the associated cryogenic facility, and controls, where operations includes the cost of the electrical utilities but not the labor or other costs. It derives from collaborative work done with staff from Accelerator Science and Technology Centre, Daresbury, UK several years ago while they were in the process of developing a conceptual design for the New Light Source project.[1] The initial goal was to convert a spread sheet format to a graphical interface to allow the ability to sweep different parameter sets. The tools also allow one to compare the cost of the different facets of the machine design and operations so as to better understand the tradeoffs. The work was first published in an ICFA Beam Dynamics News Letter.[2] More recent additions to the software include the ability to save and restore input parameters as well as to adjust the Qo versus E parameters in order to explore the potential costs savings associated with doing so. Additionally, program changes now allow one to model the costs associated with a linac that makes use of energy recovery mode of operation.

  12. Superconducting RFQs in the PIAVE Injector

    CERN Document Server

    Bisoffi, G; Bezzon, G; Calore, A; Canella, S; Chiurlotto, F; Lombardi, A; Modanese, P; Porcellato, A M; Stark, S

    2004-01-01

    The PIAVE superconducting RFQs were installed on the linac line and connected to the TCF50 cryogenic system. First results on the on-line resonator performance (e.g. Q-curves, amplitude and phase locking) are described as well as the behaviour of the fast tuners.

  13. Beam Loss Studies for Rare Isotope Driver Linacs Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Wangler, T P; Kurennoy, S S; Billen, J H; Crandall, K R; Qiang, J; Ryne, R D; Mustapha, B; Ostroumov, P; Zhao, Q; York, and R. C.

    2008-03-26

    The Fortran 90 RIAPMTQ/IMPACT code package is a pair of linked beam-dynamics simulation codes that have been developed for end-to-end computer simulations of multiple-charge-state heavy-ion linacs for future exotic-beam facilities. These codes have multiple charge-state capability, and include space-charge forces. The simulations can extend from the low-energy beam-transport line after an ECR ion source to the end of the linac. The work has been performed by a collaboration including LANL, LBNL, ANL, and MSU. The code RIAPMTQ simulates the linac front-end beam dynamics including the LEBT, RFQ, and MEBT. The code IMPACT simulates the beam dynamics of the main superconducting linac. The codes have been benchmarked for rms beam properties against previously existing codes at ANL and MSU. The codes allow high-statistics runs on parallel supercomputing platforms, particularly at NERSC at LBNL, for studies of beam losses. The codes also run on desktop PC computers for low-statistics work. The code package is described in more detail in a recent publication [1] in the Proceedings of PAC07 (2007 US Particle Accelerator Conference). In this report we describe the main activities for the FY07 beam-loss studies project using this code package.

  14. Waveguide-coupled cavities for energy recovery linacs

    Science.gov (United States)

    Kurennoy, S. S.; Nguyen, D. C.; Young, L. M.

    2004-08-01

    A novel scheme for energy recovery linacs used as FEL drivers is proposed. It consists of two parallel beam lines, one for electron beam acceleration and the other for the used beam that is bent after passing through a wiggler. The used beam is decelerated by the structure and feeds the cavity fields. The main feature of the scheme is that RF cavities are coupled with waveguides between these two linacs. The waveguide cut through the two beam pipes provides an efficient mechanism for energy transfer. The superconducting RF cavities in the two accelerators can be shaped differently, with an operating mode at the same frequency. This provides HOM detuning and therefore reduces the beam break-up effects. Another advantage of the proposed two-beam scheme is easy tuning of the cavity coupling by changing the waveguide length.

  15. Linac Envelope Optics

    CERN Document Server

    Baartman, Rick

    2015-01-01

    I develop the formalism that allows calculation of beam envelopes through a linear accelerator given its on-axis electric field. Space charge can naturally be added using Sacherer formalism. A complicating feature is that the reference particle's energy-time coordinates are not known a priori. Since first order matrix formalism applies to deviations from the reference particle, this means the reference particle's time and energy must be calculated simultaneously with the beam envelope and transfer matrix. The code TRANSOPTR is used to track envelopes for general elements whose infinitesimal transfer matrices are known, and in the presence of space charge. Incorporation of the linac algorithm into TRANSOPTR is described, and some examples given.

  16. Beam instrumentation for the HIE Isolde linac at CERN

    CERN Document Server

    Sosa, A; Fraser, MA; Kadi, Y; Voulot, D; Wenander, F; Zocca, F; Sosa, A; Welsch, CP; Larman, A; Galipienzo, J

    2012-01-01

    In the framework of the High Intensity and Energy (HIE)-ISOLDE project at CERN, a beam instrumentation R&amp;amp;D program is on-going for the superconducting upgrade of the REX-ISOLDE heavy-ion post-accelerator. An overview of the foreseen beam diagnostics system is presented, focusing on the challenging specifications required by the HIE-ISOLDE linac. Due to the low beam intensities, the beam instrumentation will be based on high-sensitivity intercepting devices. The project includes intensity, position and transverse profile monitors to be installed in the very narrow space available in between the superconducting cryomodules. In addition, spectroscopy and time of flight (ToF) monitors are foreseen downstream of the linac to measure the energy and time distribution of the beams and to allow for a fast phase tuning of the superconducting cavities. An emittance meter will finally provide transverse emittance measurements based on the phase space sampling technique. The design status of the differ...

  17. Installation of the Gbar LINAC

    CERN Multimedia

    Maximilien, Brice

    2017-01-01

    Installation of the GBAR linac in its shielding bunker. The electrons accelerated to 10 MeV toward a target will produce the positrons that are necessary to form anti hydrogen with the antiprotons coming from the ELENA decelerator.

  18. Comparison of LINAC-4 Designs

    CERN Document Server

    Crandall, K; Sargsyan, E; Lallement, J-B; CERN. Geneva. BE Department

    2009-01-01

    We have studied the expected performance of two drift tube linac (DTL) designs proposed for LINAC-4. The two designs use the same cell geometries but are characterized by different phase (φs) and accelerating field (E0) distributions. In addition we have investigated the expected performance of 3 different quadrupole focusing schemes in each design. The expected performance of these 6 variants is compared with respect to their stability and risk of beam loss with alignment errors.

  19. Testing begins on Linac4

    CERN Multimedia

    Katarina Anthony

    2012-01-01

    On 3 August 2012, the Linac4 radiofrequency quadrupole (RFQ) module was installed at the accelerator test-stand in Building 152. The site will be the module’s home for almost a year, as the linear accelerator enters the assembly and testing stage.   Final module assembly is carried out before installation in Building 152.  Over the next Long Shutdown (LS2), Linac4 will replace the current Linac2 linear accelerator as the first link in CERN’s accelerator chain. It will deliver particles at 160 MeV to the PS Booster, more than triple the energy currently delivered by Linac2. But before the accelerator team can pop the champagne, the various elements of Linac4 will be tested and re-tested in facilities across CERN. “The first Linac4 tests are currently underway, starting with the CERN-built RFQ,” says Carlo Rossi, a physicist in the RF Group of the Beams (BE) Department and the RFQ project coordinator. “It’s an extremely impre...

  20. Inner structure of Linac 2

    CERN Multimedia

    1977-01-01

    With the advent of the 800 MeV Booster in 1972, the original injector of the PS, a 50 MeV Alvarez-type proton linac, had reached its limits, in terms of intensity and stability. In 1973 one therefore decided to build a new linac (Linac 2), also with a drift-tube Alvarez structure and an energy of 50 MeV. It had a new Cockcroft-Walton preinjector with 750 keV, instead of the previous one with 500 keV. Linac 2 was put into service in 1980. The old Linac 1 was then used for the study of, and later operation with, various types of ions. This picture shows the inner structure of Linac 2, with drift-tubes hanging on stems under a rigid support structure, soon to be mounted inside tank 1 (750 keV to 10 MeV, the lowest-energy one of 3). Frank Malthouse is standing in the background.

  1. Applied superconductivity

    CERN Document Server

    Newhouse, Vernon L

    1975-01-01

    Applied Superconductivity, Volume II, is part of a two-volume series on applied superconductivity. The first volume dealt with electronic applications and radiation detection, and contains a chapter on liquid helium refrigeration. The present volume discusses magnets, electromechanical applications, accelerators, and microwave and rf devices. The book opens with a chapter on high-field superconducting magnets, covering applications and magnet design. Subsequent chapters discuss superconductive machinery such as superconductive bearings and motors; rf superconducting devices; and future prospec

  2. Induction Linac Pulsers

    Energy Technology Data Exchange (ETDEWEB)

    Faltens, Andris

    2011-01-07

    The pulsers used in most of the induction linacs evolved from the very large body of work that was done in the U.S. and Great Britain during the development of the pulsed magnetron for radar. The radar modulators started at {approx}100 kW and reached >10 MW by 1945. A typical pulse length was 1 {mu}s at a repetition rate of 1,000 pps. A very comprehensive account of the modulator development is Pulse Generators by Lebacqz and Glasoe, one of the Radiation Laboratory Series. There are many permutations of possible modulators, two of the choices being tube type and line type. In earlier notes I wrote that technically the vacuum tube pulser met all of our induction linac needs, in the sense that a number of tubes, in series and parallel if required, could produce our pulses, regulate their voltage, be useable in feed-forward correctors, and provide a low source impedance. At a lower speed, an FET array is similar, and we have obtained and tested a large array capable of >10 MW switching. A modulator with an electronically controlled output only needs a capacitor for energy storage and in a switched mode can transfer the energy from the capacitor to the load at high efficiency. Driving a full size Astron induction core and a simulated resistive 'beam load' we achieved >50% efficiency. These electronically controlled output pulses can produce the pulses we desire but are not used because of their high cost. The second choice, the line type pulser, visually comprises a closing switch and a distributed or a lumped element transmission line. The typical switch cannot open or stop conducting after the desired pulse has been produced, and consequently all of the initially stored energy is dissipated. This approximately halves the efficiency, and the original cost estimating program LIACEP used this factor of two, even though our circuits are usually worse, and even though our inveterate optimists often omit it. The 'missing' energy is that which is

  3. Object-oriented sequence analysis: SCL--a C++ class library.

    Science.gov (United States)

    Vahrson, W; Hermann, K; Kleffe, J; Wittig, B

    1996-04-01

    SCL (Sequence Class Library) is a class library written in the C++ programming language. Designed using object-oriented programming principles, SCL consists of classes of objects performing tasks typically needed for analyzing DNA or protein sequences. Among them are very flexible sequence classes, classes accessing databases in various formats, classes managing collections of sequences, as well as classes performing higher-level tasks like calculating a pairwise sequence alignment. SCL also includes classes that provide general programming support, like a dynamically growing array, sets, matrices, strings, classes performing file input/output, and utilities for error handling. By providing these components, SCL fosters an explorative programming style: experimenting with algorithms and alternative implementations is encouraged rather than punished. A description of SCL's overall structure as well as an overview of its classes is given. Important aspects of the work with SCL are discussed in the context of a sample program.

  4. The KAERI 10 MeV Electron Linac - Description and Operational Manual

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byung Cheol; Park, Seong Hee; Jung, Young Uk; Han, Young Hwan; Kang, Hee Young

    2005-06-15

    The objective of this technical report is to guide the right operation and maintenance of the KAERI electron linac system. The KAERI electron linac system consists of 2 MeV injector based on 176 MHz Normal conducting RF (Radio Frequency)cavity and 10 MeV main accelerator based on 352 MHz Superconducting RF cavity, electron beamlines (injection and extraction). Since a electron accelerator generates hazard radiation, this system is located at the shielded room in basement and we can operate the system using the remote control system. It includes the description and the operational manual as well as the detailed technical direction for trouble shooting.

  5. Superconducting Radio Frequency Technology: An Overview

    Energy Technology Data Exchange (ETDEWEB)

    Peter Kneisel

    2003-06-01

    Superconducting RF cavities are becoming more often the choice for larger scale particle accelerator projects such as linear colliders, energy recovery linacs, free electron lasers or storage rings. Among the many advantages compared to normal conducting copper structures, the superconducting devices dissipate less rf power, permit higher accelerating gradients in CW operation and provide better quality particle beams. In most cases these accelerating cavities are fabricated from high purity bulk niobium, which has superior superconducting properties such as critical temperature and critical magnetic field when compared to other superconducting materials. Research during the last decade has shown, that the metallurgical properties--purity, grain structure, mechanical properties and oxidation behavior--have significant influence on the performance of these accelerating devices. This contribution attempts to give a short overview of the superconducting RF technology with emphasis on the importance of the material properties of the high purity niobium.

  6. Radiation protection studies for a high-power 160 MeV proton linac

    CERN Document Server

    Mauro, Egidio

    2009-01-01

    CERN is presently designing a new chain of accelerators to replace the present Proton Synchrotron (PS) complex: a 160 MeV room-temperature H− linac (Linac4) to replace the present 50 MeV proton linac injector, a 3.5 GeV Superconducting Proton Linac (SPL) to replace the 1.4 GeV PS Booster (PSB) and a 50 GeV synchrotron (named PS2) to replace the 26 GeV PS. Linac4 has been funded and the civil engineering work started in October 2008, whilst the SPL is in an advanced stage of design. Beyond injecting into the future 50 GeV PS, the ultimate goal of the SPL is to generate a 4 MW beam for the production of intense neutrino beams. The radiation protection design is driven by the latter requirement. This work summarizes the radiation protection studies conducted for Linac4. FLUKA Monte Carlo simulations, complemented by analytical estimates, were performed to evaluate the propagation of neutrons through the waveguide, ventilation and cable ducts placed along the accelerator, to estimate the radiological impact of ...

  7. submitter Radiation Protection Studies for CERN LINAC4/SPL Accelerator Complex

    CERN Document Server

    Mauro, Egidio; Silari, Marco

    2009-01-01

    CERN is presently designing a new chain of accelerators to replace the present Proton Synchrotron (PS) complex: a 160 MeV room-temperature H$^-$ linac (Linac4) to replace the present 50 MeV proton linac injector, a 3.5 GeV Superconducting Proton Linac (SPL) to replace the 1.4 GeV PS booster (PSB) and a 50 GeV synchrotron (named PS2) to replace the 26 GeV PS. Linac4 has been funded and the civil engineering work started in October 2008, whilst the SPL is in an advanced stage of design. Beyond injecting into the future 50 GeV PS, the ultimate goal of the SPL is to generate a 4 MW beam for the production of intense neutrino beams. The radiation protection design is driven by the latter requirement. This thesis summarizes the radiation protection studies conducted for Linac4. FLUKA Monte Carlo simulations, complemented by analytical estimates, were performed 1) to evaluate the propagation of neutrons through the waveguide, ventilation and cable ducts placed along the accelerator, 2) to estimate the radiological i...

  8. Ampere Average Current Photoinjector and Energy Recovery Linac

    CERN Document Server

    Ben-Zvi, Ilan; Calaga, R; Cameron, P; Chang, X; Gassner, D M; Hahn, H; Hershcovitch, A; Hseuh, H C; Johnson, P; Kayran, D; Kewisch, J; Lambiase, R F; Litvinenko, Vladimir N; McIntyre, G; Nicoletti, A; Rank, J; Roser, T; Scaduto, J; Smith, K; Srinivasan-Rao, T; Wu, K C; Zaltsman, A; Zhao, Y

    2004-01-01

    High-power Free-Electron Lasers were made possible by advances in superconducting linac operated in an energy-recovery mode, as demonstrated by the spectacular success of the Jefferson Laboratory IR-Demo. In order to get to much higher power levels, say a fraction of a megawatt average power, many technological barriers are yet to be broken. BNL’s Collider-Accelerator Department is pursuing some of these technologies for a different application, that of electron cooling of high-energy hadron beams. I will describe work on CW, high-current and high-brightness electron beams. This will include a description of a superconducting, laser-photocathode RF gun employing a new secondary-emission multiplying cathode and an accelerator cavity, both capable of producing of the order of one ampere average current.

  9. Accelerators for hadrontherapy: From Lawrence cyclotrons to linacs

    Energy Technology Data Exchange (ETDEWEB)

    Amaldi, U.; Bonomi, R.; Braccini, S., E-mail: Saverio.Braccini@cern.ch; Crescenti, M.; Degiovanni, A.; Garlasche, M.; Garonna, A.; Magrin, G.; Mellace, C.; Pearce, P.; Pitta, G.; Puggioni, P.; Rosso, E.; Verdu Andres, S.; Wegner, R.; Weiss, M.; Zennaro, R.

    2010-08-21

    Hadrontherapy with protons and carbon ions is a fast developing methodology in radiation oncology. The accelerators used and planned for this purpose are reviewed starting from the cyclotrons used in the thirties. As discussed in the first part of this paper, normal and superconducting cyclotrons are still employed, together with synchrotrons, for proton therapy while for carbon ion therapy synchrotrons have been till now the only option. The latest developments concern a superconducting cyclotron for carbon ion therapy, fast-cycling high frequency linacs and 'single room' proton therapy facilities. These issues are discussed in the second part of the paper by underlining the present challenges, in particular the treatment of moving organs.

  10. Accelerators for hadrontherapy: From Lawrence cyclotrons to linacs

    CERN Document Server

    Braccini, S; Garlasche, M; Weiss, M; Crescenti, M; Pearce, P; Rosso, E; Wegner, R; Magrin, G; Pitta, G; Amaldi, U; Puggioni, P; Degiovanni, A; Mellace, C; Zennaro, R; Bonomi, R; Garonna, A

    2010-01-01

    Hadrontherapy with protons and carbon ions is a fast developing methodology in radiation oncology. The accelerators used and planned for this purpose are reviewed starting from the cyclotrons used in the thirties. As discussed in the first part of this paper, normal and superconducting cyclotrons are still employed, together with synchrotrons, for proton therapy while for carbon ion therapy synchrotrons have been till now the only option. The latest developments concern a superconducting cyclotron for carbon ion therapy, fast-cycling high frequency linacs and `single room' proton therapy facilities. These issues are discussed in the second part of the paper by underlining the present challenges, in particular the treatment of moving organs. (C) 2010 Elsevier B.V. All rights reserved.

  11. Power Coupler Simulations for the Linac4 Drift Tube Linac

    CERN Document Server

    De Michele, G; Ramberger, S

    2011-01-01

    The power coupler is a crucial element in the design of an RF cavity. Power from an RF source is transported towards the cavity by a waveguide and transferred into the cavity by means of a power coupler that is adapted to both the transport mode in the waveguide and the principal resonant mode in the cavity. In the case of Linac4, a rectangular half-height waveguide (WG) WR2300 is used and the connection from this WG to the cavity is achieved by iris coupling through an interconnecting waveguide (IWG) in the tank wall. In this note simulations and measurements on a prototype and studies on Tank1 of the Linac4 Drift Tube Linac (DTL) are discussed in order to define the dimensions of this IWG such that it optimises the power transfer into the cavity.

  12. New Results on RZ Leo and CC Scl

    Science.gov (United States)

    Szkody, Paula; Mukadam, Anjum S.; Gaensicke, Boris T.; Toloza, Odette; Dai, Zhibin; HST GO12870 Team

    2017-01-01

    Using HST COS ultraviolet spectra in time-tag mode and a long K2 observation, we have determined a spin period for the white in RZ Leo of 220 seconds, thus confirming this cataclysmic variable as a new member of the Intermediate Polar class of systems. The ultraviolet light curve of CC Scl at quiescence created from its COS spectral observations is dominated by its spin period of 195 seconds (that has only been previously observed during one of its outbursts). Spectra formed from the high and low sections of its light curve shows a temperature difference of several thousand degrees.PS and ASM acknowledge support from NASA grant HST-GO13807 and from NSF grant AST-1514737.

  13. Optimization of Steering Elements in the RIA Driver Linac

    CERN Document Server

    SchnirmanLessner, Eliane; Ostroumov, Peter

    2005-01-01

    The driver linac of the projected RIA facility is a versatile accelerator, a 1.4-GV, CW superconducting linac designed to simultaneously accelerate several heavy-ion charge states, providing beams from protons at about 1 GeV to uranium at 400 MeV/u at power levels at a minimum of 100 kW and up to 400 kW for most beams. Acceleration of multiple-charge-state uranium beams places stringent requirements on the linac design. A steering algorithm was derived that fulfilled the driver’s real estate requirements, such as placement of steering dipole coils on SC solenoids and of beam position monitors outside cryostats, and beam-dynamics requirements, such as coupling effects induced by the focusing solenoids.* The algorithm has been fully integrated in the tracking code TRACK** and is used to study and optimize the number and position of steering elements that minimize the multiple-beam centroid oscillations and preserve the beam emittance under misalignments of accelerating and transverse focusing elements...

  14. Linac3 - 1992-1994

    CERN Multimedia

    CERN; A Van der Shueren; Jean-Claude Vialis

    1995-01-01

    This film reports the differents steps of the construction in differents places (Italy, Germany, France) from 29 October 1992 to 29 April 1994. This linac, commissioned in summer 1994, presently provides beams of 208Pb53+. A 14 GHz ECR ion source operating in the "afterglow" mode produces Pb 27+ ions at 2.5 keV/u. This beam is accelerated in an RFQ and a three tank IH linac to 4.2 MeV/u where stripping in a 1 um carbon foil to a charge state distribution centered around Pb53+ takes place. 53+ ions are selected from this mixture in a magnetic filter before being transported to the PS Booster and other circular machines. Linac3, the more common name for this machine, was built by a truly international collaboration involving France, Italy, Germany, Italy, Sweden, Switzerland, India, the Czech Republic and CERN.

  15. Translational control of SCL-isoform expression in hematopoietic lineage choice

    NARCIS (Netherlands)

    Calkhoven, Cornelis F; Muller, Christine; Martin, Richard; Krosl, Goradz; Pietsch, Hubertus; Hoang, Trang; Leutz, Achim

    2003-01-01

    We investigated the translational regulation of SCL protein expression and its role in hematopoietic lineage choice. We show that the expression of different SCL protein isoforms is regulated by signal transduction pathways that modulate translation initiation factor (eIF) function. A conserved smal

  16. An enzyme-linked immunosorbent assay for autoantibodies against the nuclear protein Scl-70

    DEFF Research Database (Denmark)

    Geisler, C; Høier-Madsen, M

    1985-01-01

    This paper describes the development of an enzyme-linked immunosorbent assay (ELISA) for the detection and quantitation of autoantibodies against the nuclear protein Scl-70. The isolation of Scl-70 from rat livers and the conditions for the ELISA are described. Compared with the already established...

  17. ARIEL e-linac. Electron linear accelerator for photo-fission

    Science.gov (United States)

    Koscielniak, Shane

    2014-01-01

    The design and implementation of a 1/2 MW beam power electron linear accelerator (e-linac) for the production of rare isotope beams (RIB) via photo-fission in the context of the Advanced Rare IsotopE Laboratory, ARIEL (Koscielniak et al. 2008; Merminga et al. 2011; Dilling et al., Hyperfine Interact, 2013), is described. The 100 % duty factor e-linac is based on super-conducting radiofrequency (SRF) technology at 1.3 GHz and has a nominal energy of 50 MeV. This paper provides an overview of the accelerator major components including the gun, cryomodules and cryoplant, high power RF sources, and machine layout including beam lines. Design features to facilitate operation of the linac as a Recirculating Linear Accelerator (RLA) for various applications, including Free Electron Lasers, are also noted.

  18. A CONCEPTUAL 3-GEV LANSCE LINAC UPGRADE FOR ENHANCED PROTON RADIOGRAPHY

    Energy Technology Data Exchange (ETDEWEB)

    Garnett, Robert W [Los Alamos National Laboratory; Rybarcyk, Lawrence J. [Los Alamos National Laboratory; Merrill, Frank E. [Los Alamos National Laboratory; O' Hara, James F. [Los Alamos National Laboratory; Rees, Daniel E. [Los Alamos National Laboratory; Walstrom, Peter L. [Los Alamos National Laboratory

    2012-05-14

    A conceptual design of a 3-GeV linac upgrade that would enable enhanced proton radiography at the Los Alamos Neutron Science Center (LANSCE) is presented. The upgrade is based on the use of superconducting accelerating cavities to increase the present LANSCE linac output energy from 800 MeV to 3 GeV. The LANSCE linac currently provides negative hydrogen ion (H{sup -}) and proton (H{sup +}) beams to several user facilities that support Isotope Production, NNSA Stockpile Stewardship, and Basic Energy Science programs. Required changes to the front-end, the accelerating structures, and to the RF systems to meet the new performance goals, and changes to the existing beam switchyard to maintain operations for a robust user program are also described.

  19. LUX - A recirculating linac-based ultrafast X-ray source

    Energy Technology Data Exchange (ETDEWEB)

    Corlett, J.N.; Barletta, W.A.; DeSantis, S.; Doolittle, L.; Fawley, W.M.; Green, M.A.; Heimann, P.; Leone, S.R.; Lidia, S.; Li, D.; Parmigiani, F.; Ratti, A.; Robinson, K.; Schoenlein, R.; Staples, J.; Wan, W.; Wells, R.; Wilcox, R.; Wolski, A.; Zholents, A.

    2003-08-01

    We describe the design of a proposed source of ultra-fast synchrotron radiation x-ray pulses based on a recirculating superconducting linac, with an integrated array of ultrafast laser systems. The source produces x-ray pulses with duration of 10-50 fs at a 10 kHz repetition rate, with tunability from EUV to hard x-ray regimes, and optimized for the study of ultra-fast dynamics. A high-brightness rf photocathode provides electron bunches. An injector linac accelerates the beam to the 100 MeV range, and is followed by four passes through a 700 MeV recirculating linac. Ultrafast hard x-ray pulses are obtained by a combination of electron bunch manipulation, transverse temporal correlation of the electrons, and x-ray pulse compression. EUV and soft x-ray pulses as short as 10 fs are generated in a harmonic-cascade free electron laser scheme.

  20. Commissioning of the 112 MHz SRF Gun and 500 MHz bunching cavities for the CeC PoP Linac

    Energy Technology Data Exchange (ETDEWEB)

    Belomestnykh, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., NY (United States); Ben-Zvi, I. [Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., NY (United States); Brutus, J. C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Litvinenko, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., NY (United States); McIntosh, P. [Science and Technology Facilities Council (STFC), Daresbury (United Kingdom). Daresbury Lab.; Moss, A. [Science and Technology Facilities Council (STFC), Daresbury (United Kingdom). Daresbury Lab.; Narayan, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Orfin, P. [Brookhaven National Lab. (BNL), Upton, NY (United States); Pinayev, I. [Brookhaven National Lab. (BNL), Upton, NY (United States); Rao, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Skaritka, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Smith, K. [Brookhaven National Lab. (BNL), Upton, NY (United States); Than, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Tuozzolo, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Wang, E. [Brookhaven National Lab. (BNL), Upton, NY (United States); Wheelhouse, A. [Science and Technology Facilities Council (STFC), Daresbury (United Kingdom). Daresbury Lab.; Wu, Q. [Brookhaven National Lab. (BNL), Upton, NY (United States); Xiao, B. [Brookhaven National Lab. (BNL), Upton, NY (United States); Xin, T. [Stony Brook Univ., NY (United States); Xu, W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Zaltsman, A. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-05-03

    The Coherent electron Cooling Proof-of-Principle (CeC PoP) experiment at BNL includes a short electron linac. During Phase 1, a 112 MHz superconducting RF photo-emission gun and two 500 MHz normal conducting bunching cavities were installed and are under commissioning. The paper describes the Phase1 linac layout and presents commissioning results for the cavities and associated RF, cryogenic and other sub-systems

  1. Drift Tube Linac Conditioning of Tank1

    CERN Document Server

    Shafqat, N; Toor, W A

    2014-01-01

    Tank1 of the Drift Tube Linac (DTL) of the Linac4 has been conditioned at the Linac4 tunnel. The tank was tuned for resonance at 352.2 MHz, and stable operation has been achieved with 725 µs long RF pulses at a repetition rate of 1 Hz. The maximum RF level that has been reached is 810 kW with a pulse width of 600 µs. Since this was the first RF structure exclusively conditioned in the Linac4 tunnel with the operation and control software of Linac4, some related issues and limitations had to be taken into account.

  2. The new Linac moves mountains

    CERN Multimedia

    2008-01-01

    The civil engineering work has started for Linac 4, one of the major renovation projects for the CERN accelerator complex. The work will be completed at the end of 2010 and the new linear accelerator is scheduled to be commissioned in 2013.

  3. Niobium coaxial quarter-wave cavities for the New Delhi booster linac

    Energy Technology Data Exchange (ETDEWEB)

    Shepard, K.W. [Argonne National Lab., IL (United States); Roy, A.; Potukuchi, P.N. [Nuclear Science Centre, New Delhi (India)

    1993-07-01

    This paper reports the design and construction status of a prototype superconducting niobium accelerating structure consisting of a pair of quarter-wave coaxial-line cavities which are strongly coupled with a superconducting loop. Quarter-wave resonators are two-gap accelerating structures and are relatively short, so that a large number of independently-phased cavities is required for a linac. Strongly coupling several cavities can reduce the number of independently-phased elements, but at the cost of reducing the range of useful velocity acceptance for each element. Coupling two cavities splits the accelerating rf eigenmode into two resonant modes each of which covers a portion of the full velocity acceptance range of the original single cavity mode. Using both of these resonant modes makes feasible the use of coupled cavity pairs for a linac with little loss m velocity acceptance. Design details for the niobium cavity pair and the results of preliminary tests of multipacting behavior are discussed.

  4. Large-acceptance linac for accelerating l9w-energy muons

    Energy Technology Data Exchange (ETDEWEB)

    Kurennoy, Sergey S [Los Alamos National Laboratory; Jason, Andrew J [Los Alamos National Laboratory; Miyadera, Haruo [Los Alamos National Laboratory

    2010-01-01

    We propose a high-gradient linear accelerator for accelerating low-energy muons and pions in a strong solenoidal magnetic field. The acceleration starts immediately after collection of pions from a target by solenoidal magnets and brings muons to a kinetic energy of about 200 MeV over a distance of the order of 10 m. At this energy, both an ionization cooling of the muon beam and its further acceleration in a superconducting linac become feasible. The project presents unique challenges - a very large energy spread in a highly divergent beam, as well as pion and muon decays - requiring large longitudinal and transverse acceptances. One potential solution incorporates a normal-conducting linac consisting of independently fed O-mode RF cavities with wide apertures closed by thin metal windows or grids. The guiding magnetic field is provided by external superconducting solenoids. The cavity choice, overall linac design considerations, and simulation results of muon acceleration are presented. While the primary applications of such a linac are for homeland defense and industry, it can provide muon fluxes high enough to be of interest for physics experiments.

  5. Check list of symptoms SCL-90-R at persons with extremities amputations.

    Science.gov (United States)

    Kapidzić-Duraković, Suada; Karabegović, Azra; Halilbegović, Emir; Cićkusić, Amela; Osmanović, Nusret; Kudumović, Zijada

    2006-02-01

    Multidimensional Inventory Check List of Symptoms (SCL-90-r) is based on self-evaluation and it has been used for determination of level of: somatisation, obsessive-compulsive symptoms, interpersonal sensitivity, depression, anxiety, hostility, phobias, paranoia and psychosis at persons which are exposed to long term emotional and physical stress. Our goal was to determine relations of physical trauma and psychological changes at persons with lower extremities amputations and to determine factors which influence those changes. Thirty seven persons with lower extremities amputations were examined. The sample included 26 (70.2 %) veterans and 11 (29.7 %) civilians with diseases related amputations. They voluntarily filled Check List of Symptoms SCL-90-r. Symptoms Inventory includes 9 dimensions of primary symptoms: SCL1-somatisation, SCL2-obsessive-compulsive symptoms, SCL3-interpersonal sensitivity, SCL4-depression, SCL5-anxiety, SCL6-hostility, SCL7-phobias, SCL8-paranoia, SCL9-psychosis and SCL10-extra scale. Inventory includes 90 statements, each evaluated with five-level scale of disorder. Every answer is graded with 0-4 points. Thirty seven persons with lower extremities amputations and average chronological age 46.2 +/- 10.92 years were analyzed. Considering marital status 30 (81.1 %) of them were married, 4 (10.8 %) were not married and 3 (8.1 %) were widowers. Considering level of amputation 27 of them (73.0 %) had amputation below knee, 5 (13.5 %) of them amputation above knee and 5 of them (13.5 %) foot amputation. SCL-90-r in both groups determined high level of sensitivity, anxiety, hostility and paranoia. Veterans showed higher level of paranoia comparing to civilians (p<0.002), and younger veterans and married ones had higher level of paranoia comparing to other veterans (p<0.01). Persons with amputations below and above knee showed higher level of paranoia comparing those with foot amputation (p<0.001). Persons with lower extremities amputations have

  6. Analysis of HOM Problems in the C-ADS Main Linac

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Burn [Chinese Academy of Sciences (CAS), Lanzhou (China). Inst. of Modern Physics; Ng, King Yuen [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2017-05-18

    Excitation of higher-order modes (HOMs) in superconducting cavities may severely affect the operation of the main linac in the Chinese Accelerator Driven System (CADS). Preliminary analysis is made on the effects of beam dynamic, which includes possible longitudinal and transverse emittance enlargements, as well as the possibility of beam breakup. Suggestions are given for further investigation. Comparison is made between the C-ADS and the Fermilab Project X.

  7. Studies of a Linac Driver for a High Repetition Rate X-Ray FEL

    Energy Technology Data Exchange (ETDEWEB)

    Venturini, M.; Corlett, J.; Doolittle, L.; Filippetto, D.; Papadopoulos, C.; Penn, G.; Prosnitz, D.; Qiang, J.; Reinsch, M.; Ryne, R.; Sannibale, F.; Staples, J.; Wells, R.; Wurtele, J.; Zolotorev, M.; Zholents, A.

    2011-06-01

    We report on on-going studies of a superconducting CW linac driver intended to support a high repetition rate FEL operating in the soft x-rays spectrum. We present a pointdesign for a 1.8 GeV machine tuned for 300 pC bunches and delivering low-emittance, low-energy spread beams as needed for the SASE and seeded beamlines.

  8. Overview on superconducting photoinjectors

    Directory of Open Access Journals (Sweden)

    A. Arnold

    2011-02-01

    Full Text Available The success of most of the proposed energy recovery linac (ERL based electron accelerator projects for future storage ring replacements (SRR and high power IR–free-electron lasers (FELs largely depends on the development of an appropriate source. For example, to meet the FEL specifications [J. W. Lewellen, Proc. SPIE Int. Soc. Opt. Eng. 5534, 22 (2004PSISDG0277-786X10.1117/12.557378] electron beams with an unprecedented combination of high brightness, low emittance (0.1  μmrad, and high average current (hundreds of mA are required. An elegant way to create a beam of such quality is to combine the high beam quality of a normal conducting rf photoinjector with the superconducting technology, i.e., to build a superconducting rf photoinjector (SRF gun. SRF gun R&D programs based on different approaches have been launched at a growing number of institutes and companies (AES, Beijing University, BESSY, BNL, DESY, FZD, TJNAF, Niowave, NPS, Wisconsin University. Substantial progress was achieved in recent years and the first long term operation was demonstrated at FZD [R. Xiang et al., in Proceedings of the 31st International Free Electron Laser Conference (FEL 09, Liverpool, UK (STFC Daresbury Laboratory, Warrington, 2009, p. 488]. In the near future SRF guns are expected to play an important role for linac-driven FEL facilities. In this paper we will review the concepts, the design parameters, and the status of the major SRF gun projects.

  9. Superconducting transistor

    Science.gov (United States)

    Gray, Kenneth E.

    1979-01-01

    A superconducting transistor is formed by disposing three thin films of superconducting material in a planar parallel arrangement and insulating the films from each other by layers of insulating oxides to form two tunnel junctions. One junction is biased above twice the superconducting energy gap and the other is biased at less than twice the superconducting energy gap. Injection of quasiparticles into the center film by one junction provides a current gain in the second junction.

  10. Installation and Commissioning of the Super Conducting RF Linac Cryomodules for the Erlp

    Science.gov (United States)

    Goulden, A. R.; Bate, R.; Buckley, R. K.; Pattalwar, S. M.

    2008-03-01

    An Energy Recovery Linac Prototype (ERLP) is currently being constructed at Daresbury Laboratory, (UK) to promote the necessary skills in science & technology, particularly in photocathode electron gun and Superconducting RF (SRF), to enable the construction of a fourth generation light source, based on energy recovery linacs-4GLS [1]. The ERLP uses two identical cryomodules, one as a booster Linac used to accelerate the beam to 8.5 MeV, the other as an Energy Recovery Linac (ERL) module with an energy gain of 26.5 MeV. Each module consists of two 9- cell cavities operating at a frequency of 1.3 GHz and a temperature of 2 K. As there is no energy recovery in the booster it requires a peak power of 53 kW; whereas the linac module only requires 8 kW. The RF power is supplied by Inductive Output Tube (IOT) amplifiers. The maximum heat load (or the cooling power) required in the SRF system is 180 W at 2 K and is achieved in two stages: a LN2 pre-cooled Linde TCF50 liquefier produces liquid helium at 4.5 K, followed by a 2 K cold box consisting of a JT valve, recuperator and an external room temperature vacuum pumping system. This presentation reports the experience gained during, installation, commissioning and the initial operation of the cryomodules.

  11. Physics design of a CW high-power proton Linac for accelerator-driven system

    Indian Academy of Sciences (India)

    Rajni Pande; Shweta Roy; S V L S Rao; P Singh; S Kailas

    2012-02-01

    Accelerator-driven systems (ADS) have evoked lot of interest the world over because of their capability to incinerate the MA (minor actinides) and LLFP (long-lived fission products) radiotoxic waste and their ability to utilize thorium as an alternative nuclear fuel. One of the main subsystems of ADS is a high energy (∼1 GeV) and high current (∼30 mA) CW proton Linac. The accelerator for ADS should have high efficiency and reliability and very low beam losses to allow hands-on maintenance. With these criteria, the beam dynamics simulations for a 1 GeV, 30 mA proton Linac has been done. The Linac consists of normal-conducting radio-frequency quadrupole (RFQ), drift tube linac (DTL) and coupled cavity drift tube Linac (CCDTL) structures that accelerate the beam to about 100 MeV followed by superconducting (SC) elliptical cavities, which accelerate the beam from 100 MeV to 1 GeV. The details of the design are presented in this paper.

  12. Design of a 120 MeV $H^{-}$ Linac for CERN High-Intensity Applications

    CERN Document Server

    Gerigk, F

    2002-01-01

    The SPL (Superconducting Proton Linac) study at CERN foresees the construction of a 2.2 GeV linac as a high beam-power driver for applications such as a second-generation radioactive ion beam facility or a neutrino superbeam. At the same time such a high-performance injector would both modernize and improve the LHC injection chain. The 120 MeV normal-conducting section of the SPL could be used directly in a preliminary stage for H- charge-exchange injection into the PS Booster. This would increase the proton flux to the CERN experiments while also improving the quality and reliability of the beams for the LHC. The 120 MeV linac consists of a front-end, a conventional Drift Tube Linac (DTL) to 40 MeV and a Cell Coupled Drift Tube Linac (CCDTL) to the full energy. All the RF structures will operate at 352 MHz, using klystrons and RF equipment recovered from the LEP collider. This paper concentrates on the design of the 3 to 120 MeV section. It introduces the design criteria for high-stability beam optics and th...

  13. Genomic approaches uncover increasing complexities in the regulatory landscape at the human SCL (TAL1 locus.

    Directory of Open Access Journals (Sweden)

    Pawandeep Dhami

    Full Text Available The SCL (TAL1 transcription factor is a critical regulator of haematopoiesis and its expression is tightly controlled by multiple cis-acting regulatory elements. To elaborate further the DNA elements which control its regulation, we used genomic tiling microarrays covering 256 kb of the human SCL locus to perform a concerted analysis of chromatin structure and binding of regulatory proteins in human haematopoietic cell lines. This approach allowed us to characterise further or redefine known human SCL regulatory elements and led to the identification of six novel elements with putative regulatory function both up and downstream of the SCL gene. They bind a number of haematopoietic transcription factors (GATA1, E2A LMO2, SCL, LDB1, CTCF or components of the transcriptional machinery and are associated with relevant histone modifications, accessible chromatin and low nucleosomal density. Functional characterisation shows that these novel elements are able to enhance or repress SCL promoter activity, have endogenous promoter function or enhancer-blocking insulator function. Our analysis opens up several areas for further investigation and adds new layers of complexity to our understanding of the regulation of SCL expression.

  14. SCL/TAL1-mediated transcriptional network enhances megakaryocytic specification of human embryonic stem cells.

    Science.gov (United States)

    Toscano, Miguel G; Navarro-Montero, Oscar; Ayllon, Veronica; Ramos-Mejia, Veronica; Guerrero-Carreno, Xiomara; Bueno, Clara; Romero, Tamara; Lamolda, Mar; Cobo, Marien; Martin, Francisco; Menendez, Pablo; Real, Pedro J

    2015-01-01

    Human embryonic stem cells (hESCs) are a unique in vitro model for studying human developmental biology and represent a potential source for cell replacement strategies. Platelets can be generated from cord blood progenitors and hESCs; however, the molecular mechanisms and determinants controlling the in vitro megakaryocytic specification of hESCs remain elusive. We have recently shown that stem cell leukemia (SCL) overexpression accelerates the emergence of hemato-endothelial progenitors from hESCs and promotes their subsequent differentiation into blood cells with higher clonogenic potential. Given that SCL participates in megakaryocytic commitment, we hypothesized that it may potentiate megakaryopoiesis from hESCs. We show that ectopic SCL expression enhances the emergence of megakaryocytic precursors, mature megakaryocytes (MKs), and platelets in vitro. SCL-overexpressing MKs and platelets respond to different activating stimuli similar to their control counterparts. Gene expression profiling of megakaryocytic precursors shows that SCL overexpression renders a megakaryopoietic molecular signature. Connectivity Map analysis reveals that trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA), both histone deacetylase (HDAC) inhibitors, functionally mimic SCL-induced effects. Finally, we confirm that both TSA and SAHA treatment promote the emergence of CD34(+) progenitors, whereas valproic acid, another HDAC inhibitor, potentiates MK and platelet production. We demonstrate that SCL and HDAC inhibitors are megakaryopoiesis regulators in hESCs.

  15. Modification and Potential Application of Short-Chain-Length Polyhydroxyalkanoate (SCL-PHA

    Directory of Open Access Journals (Sweden)

    Shichao Wang

    2016-07-01

    Full Text Available As the only kind of naturally-occurring biopolyester synthesized by various microorganisms, polyhydroxyalkanoate (PHA shows a great market potential in packaging, fiber, biomedical, and other fields due to its biodegradablity, biocompatibility, and renewability. However, the inherent defects of scl-PHA with low 3HV or 4HB content, such as high stereoregularity, slow crystallization rate, and particularly the phenomena of formation of large-size spherulites and secondary crystallization, restrict the processing and stability of scl-PHA, as well as the application of its products. Many efforts have focused on the modification of scl-PHA to improve the mechanical properties and the applicability of obtained scl-PHA products. The modification of structure and property together with the potential applications of scl-PHA are covered in this review to give a comprehensive knowledge on the modification and processing of scl-PHA, including the effects of physical blending, chemical structure design, and processing conditions on the crystallization behaviors, thermal stability, and mechanical properties of scl-PHA.

  16. End-to-End Beam Simulations for the MSU RIA Driver Linac

    CERN Document Server

    Wu, X; Gorelov, D; Grimm, T L; Marti, F; York, R C; Zhao, Q

    2004-01-01

    The Rare Isotope Accelerator (RIA) driver linac proposed by Michigan State University (MSU) will use a 10th sub-harmonic based, superconducting, cw linac to accelerate light and heavy ions to final energies of ≤400 MeV/u with beam powers of 100 to 400 kW. The driver linac uses superconducting quarter-wave, half-wave, and six-cell elliptical cavities with frequencies ranging from 80.5 MHz to 805 MHz for acceleration, and superconducting solenoids and room temperature quadrupoles for transverse focusing. For the heavier ions, two stages of charge-stripping and multiple-charge-state acceleration will be used to meet the beam power requirements and to minimize the requisite accelerating voltage. End-to-end, three-dimensional (3D), beam dynamics simulations from the ECR to the radioactive beam production targets have been performed. These studies include a 3D analysis of multi-charge-state beam acceleration, evaluation of transverse misalignment and rf errors on the machine performance, modeling of the c...

  17. Superconductivity and superconductive electronics

    Science.gov (United States)

    Beasley, M. R.

    1990-12-01

    The Stanford Center for Research on Superconductivity and Superconductive Electronics is currently focused on developing techniques for producing increasingly improved films and multilayers of the high-temperature superconductors, studying their physical properties and using these films and multilayers in device physics studies. In general the thin film synthesis work leads the way. Once a given film or multilayer structure can be made reasonably routinely, the emphasis shifts to studying the physical properties and device physics of these structures and on to the next level of film quality or multilayer complexity. The most advanced thin films synthesis work in the past year has involved developing techniques to deposit a-axis and c-axis YBCO/PBCO superlattices and related structures. The in-situ feature is desirable because no solid state reactions with accompanying changes in volume, morphology, etc., that degrade the quality of the film involved.

  18. first tank of Linac 1

    CERN Multimedia

    This was the first tank of the linear accelerator Linac1, the injection system for the Proton Synchrotron, It ran for 34 years (1958 - 1992). Protons entered at the far end and were accelerated between the copper drift tubes by an oscillating electromagnetic field. The field flipped 200 million times a second (200 MHz) so the protons spent 5 nanoseconds crossing a drift tube and a gap. Moving down the tank, the tubes and gaps had to get longer as the protons gained speed. The tank accelerated protons from 500 KeV to 10 MeV. Linac1 was also used to accelerate deutrons and alpha particles for the Intersecting Storage Rings and oxygen and sulpher ions for the Super Proton Synchrotron heavy ion programme.

  19. Status of the RFD Linac Structure Developement

    CERN Document Server

    Swenson, D A

    2000-01-01

    The Proof-of-Principle (POP) prototype of the Rf-Focused Drift tube (RFD) linac structure is currently under test at Linac Systems, after years of delay due to a variety of technical problems. A discussion of these technical problems and their solutions will be presented. The status of these tests will be reported. Plans for future development of this linac structure will be revealed. Potential uses of this linac structure for a variety of scientific, medical, and industrial applications will be described, including: proton linac injectors for proton synchrotrons, compact proton linacs for PET isotope production, epithermal neutron sources for the BNCT application, energy boosters for proton therapy, compact portable neutron sources for thermal neutron radiography, and pulsed cold neutron sources for cold neutron physics and related applications.

  20. The LINAC4 Power Coupler

    CERN Document Server

    Gerigk, F; Montesinos, E; Riffaud, B; Ugena Tirado, P; Wegner, R

    2011-01-01

    Linac4 is employing three types of accelerating structures after the RFQ: a Drift Tube Linac (DTL), a Cell- Coupled DTL (CCDTL), and a Pi-Mode Structure (PIMS) to accelerate the beam up to 160 MeV at 352.2MHz. The structures are designed for a peak power of approximately 1 MW per power coupler, which is transported via rectangular waveguides from the klystron gallery to the RF cavities. The coupler itself consists of two parts: a ceramic window, which separates the cavity vacuum from the air in the waveguides, and a Tuner-adjustablewaveguide Coupler (TaCo), which couples the RF power through an iris to the cavity. In the frame of the Linac4 R&D both devices have been significantly improvedwith respect to their commonly used design. On the coupler side, the waveguide short circuit with its matched length has been replaced by a fixedlength /4 short circuit. The RF matching is done by a simple piston tuner, which allows a quick matching to different cavity quality factors. In the window part, which usually c...

  1. LFSC - Linac Feedback Simulation Code

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, Valentin; /Fermilab

    2008-05-01

    The computer program LFSC (<Linac Feedback Simulation Code>) is a numerical tool for simulation beam based feedback in high performance linacs. The code LFSC is based on the earlier version developed by a collective of authors at SLAC (L.Hendrickson, R. McEwen, T. Himel, H. Shoaee, S. Shah, P. Emma, P. Schultz) during 1990-2005. That code was successively used in simulation of SLC, TESLA, CLIC and NLC projects. It can simulate as pulse-to-pulse feedback on timescale corresponding to 5-100 Hz, as slower feedbacks, operating in the 0.1-1 Hz range in the Main Linac and Beam Delivery System. The code LFSC is running under Matlab for MS Windows operating system. It contains about 30,000 lines of source code in more than 260 subroutines. The code uses the LIAR ('Linear Accelerator Research code') for particle tracking under ground motion and technical noise perturbations. It uses the Guinea Pig code to simulate the luminosity performance. A set of input files includes the lattice description (XSIF format), and plane text files with numerical parameters, wake fields, ground motion data etc. The Matlab environment provides a flexible system for graphical output.

  2. High-Power Linac for the Spallation Neutron Source

    Science.gov (United States)

    Rej, D. J.

    2002-04-01

    The Spallation Neutron Source (SNS) will be the world’s most intense source of neutrons for fundamental science and industrial applications. Design and construction of this facility, located at Oak Ridge, is a joint venture between six DOE laboratories. Construction began in 1999 and is currently ahead of the scheduled 2006 completion date. Injecting a high-power, pulsed proton beam into a mercury target produces neutrons. In this talk, we review the physics requirements, design, and status of the construction of the 1-GeV, 1.4-MW average power RF linac for SNS. The accelerator consists of a drift tube linac (DTL), a coupled-cavity linac (CCL), and a superconducting rf (SRF) linac. The phase and quadrupole settings are set to avoid structure and parametric resonances, with coherent resonances posing minimal risk for emittance growth. The DTL is 37 m long and accelerates the ions to 87 MeV. The CCL is 55 m long and accelerates the ions to 186 MeV. The rf structure design and stability for both the DTL and CCL have been validated with scale models. The SRF linac has a modular design to accelerate ions to 1000 MeV, with a straightforward upgrade to 1.3 GeV at a later date. 3D particle-in-cell simulations of beam dynamics are performed to validate performance. The accelerator utilizes 93 MW of pulsed power operating continuously at 60-Hz with an 8factor. Approximately one hundred 402.5 or 805-MHz klystrons, with outputs between 0.55 and 5 MW, are used. The klystrons are powered by a novel converter-modulator that takes advantage of recent advances in IGBT switch plate assemblies and low-loss material cores for boost transformer. Beam diagnostics include position, phase, profile, and current monitors. They are designed to enable accurate beam steering and matching, and to minimize beam loss that would lead to activation and prevent hands-on maintenance.

  3. Fast Chopper Structure for the CERN Superconducting Proton Linac

    CERN Document Server

    Caspers, Friedhelm; Kurennoy, S S

    2002-01-01

    The SPL chopper is a travelling wave device, which deflects a slow beam (b = v/c = 0.08) by its transverse electric field. We discuss the chopper deflecting structure based on a meander line printed on an alumina substrate. This concept profits from the radiation resistance of alumina, its excellent out-gassing properties and its good thermal conductivity. The use of well established MIC (microwave integrated circuit) thick film technology allows easy implementation of prototypes; the thickness of the printed layer should be increased by means of an electrochemical deposition method. The topology of the structure has been chosen from standard MIC layouts and was subsequently optimized using numerical simulations. Several prototypes have been manufactured and measurements have shown encouraging results.

  4. Linac design for intense hadron beams

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chuan

    2009-12-14

    Based on the RFQ and H-type DTL structures, this dissertation is dedicated to study the beam dynamics in the presence of significantly strong space-charge effects while accelerating intense hadron beams in the low- and medium-{beta} region. Besides the 5 mA/30 mA, 17 MeV proton injector (RFQ+DTL) and the 125 mA, 40 MeV deuteron DTL of the EUROTRANS and IFMIF facilities, a 200 mA, 700 keV proton RFQ has been also intensively studied for a small-scale but ultra-intense neutron source FRANZ planned at Frankfurt University. The most remarkable properties of the FRANZ RFQ and the IFMIF DTL are the design beam intensities, 200 mA and 125 mA. A new design approach, which can provide a balanced and accelerated beam bunching at low energy, has been developed for intense beams. To design the IFMIF DTL and the injector DTL part of the EUROTRANS driver linac, which have been foreseen as the first real applications of the novel superconducting CH-DTL structure, intensive attempts have been made to fulfill the design goals under the new conditions. For the IFMIF DTL, the preliminary IAP design has been considerably improved with respect to the linac layout as well as the beam dynamics. By reserving sufficient drift spaces for the cryosystem, diagnostic devices, tuner and steerer, introducing SC solenoid lenses and adjusting the accelerating gradients and accordingly other configurations of the cavities, a more realistic, reliable and efficient linac system has been designed. On the other hand, the specifications and positions of the transverse focusing elements as well as the phase- and energy-differences between the bunch-center particle and the synchronous particle at the beginning of the {phi}{sub s}=0 sections have been totally redesigned. For the EUROTRANS injector DTL, in addition to the above-mentioned procedures, extra optimization concepts to coordinate the beam dynamics between two intensities have been applied. In the beam transport simulations for both DTL designs

  5. The Symptom Checklist-core depression (SCL-CD6) scale

    DEFF Research Database (Denmark)

    Magnusson Hanson, Linda L; Westerlund, Hugo; Leineweber, Constanze

    2014-01-01

    AIMS: Major depressive disorders are common, with substantial impact on individuals/society. Brief scales for depression severity, based on a small number of characteristics all of which are necessary for diagnosis, have been recommended in self-reported versions for clinical work or research when...... aiming to quickly and accurately measure depression. We have examined psychometric properties of a brief 6-item version of the Symptom Checklist (SCL), the Symptom Checklist core depression scale (SCL-CD6) and aimed to identify a cut-point for epidemiological research. METHODS: The psychometric...... evaluation of the SCL-CD6 was mainly performed by a Mokken analysis of unidimensionality in a random sample of 1476 residents in the Stockholm County, aged 18-64 years. The standardization of SCL-CD6 was based on ROC analysis, using the Major Depression Inventory as index of validity. Predictive validity...

  6. Detection of superhumps in the VY Scl-type nova-like variable KR Aur

    CERN Document Server

    Kozhevnikov, V P

    2007-01-01

    We report on detection of negative superhumps in KR Aur which is the representative member of the VY Scl stars. The observations were obtained with the multi-channel photometer during 107 h. The analysis of the data clearly revealed brightness variations with a period of 3.771 +/- 0.005 h. This is 3.5 per cent less than the orbital period, suggesting it is a negative superhump. Negative superhumps in VY Scl stars are widely spread. The discovery of powerful soft X-rays from V751 Cyg demonstrates that VY Scl stars may contain white dwarfs, at which nuclear burning of the accreted material occur. If this suspicion is correct, we then can suppose that the powerful radiation emerging from the white dwarf may cause the tilt of the accretion disk to the orbital plane, and its retrograde precession may produce negative superhumps in VY Scl stars.

  7. Status of the Linac Coherent Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Galayda, John N.; /SLAC

    2011-11-04

    The Linac Coherent Light Source (LCLS) is a free electron laser facility in construction at Stanford Linear Accelerator Center. It is designed to operate in the wavelength range 0.15-1.5 nanometers. At the time of this conference, civil construction of new tunnels and buildings is complete, the necessary modifications to the SLAC linac are complete, and the undulator system and x-ray optics/diagnostics are being installed. The electron gun, 135 MeV injector linac and 250 MeV bunch compressor were commissioned in 2007. Accelerator commissioning activities are presently devoted to the achievement of performance goals for the completed 14 GeV linac.

  8. Designs for a LINAC-Ring LHEC

    CERN Document Server

    Zimmermann, F; Ciapala, E; Haug, F; Osborne, J; Schulte, D; Tomas, R; Adolphsen, C; Sun, Y; Calaga, R; Litvinenko, V; Dainton, J; Klein, M; Chattopadhyay, S; Eide, A

    2010-01-01

    We consider three scenarios for the recirculating electron linear accelerator (RLA) of a linac-ring type electronproton collider based on the LHC (LHeC): i) a pulsed linac with a final beam energy of 60 GeV [“p-60”], ii) a higher luminosity configuration with two cw linacs and energyrecovery (ERL) also at 60 GeV [“erl”], and iii) a high energy option using a pulsed linac with 140-GeV final energy [“p-140”]. We discuss parameters, synchrotron radiation, footprints, and performance for the three scenarios.

  9. Status of the RFI Linac Prototype

    CERN Document Server

    Swenson, D A

    2004-01-01

    A prototype of the Rf Focused Interdigital (RFI) linac structure is currently under construction at Linac Systems. The RFI linac structure is basically an interdigital (or Wideröe) linac structure with rf quadrupole focusing incorporated into each drift tube. The 200 MHz RFI prototype, consisting of a short RFQ linac followed by a short RFI linac, will accelerate a 20 mA beam of protons from an injection energy of 25 keV to an output energy of 2.50 MeV in a total linac structure length of 1.44 meters. The linac structures are designed for continuous (cw) operation, and will be tested initially at a 33% duty factor. The peak structure power of 66 kW and peak beam power of 50 kW will be supplied by a 144 kW, 33% duty rf power system. A microwave ion source will supply the proton beam and an articulated Einzel lens will steer and focus the beam into the RFQ aperture. The mechanical design of the linac structures will be presented, the calculated performance will be described, the status of the components will b...

  10. Overview on superconducting photoinjectors

    CERN Document Server

    Arnold, A

    2011-01-01

    The success of most of the proposed energy recovery linac (ERL) based electron accelerator projects for future storage ring replacements (SRR) and high power IR–free-electron lasers (FELs) largely depends on the development of an appropriate source. For example, to meet the FEL specifications [J.W. Lewellen, Proc. SPIE Int. Soc. Opt. Eng. 5534, 22 (2004)] electron beams with an unprecedented combination of high brightness, low emittance (0.1 µmrad), and high average current (hundreds of mA) are required. An elegant way to create a beam of such quality is to combine the high beam quality of a normal conducting rf photoinjector with the superconducting technology, i.e., to build a superconducting rf photoinjector (SRF gun). SRF gun R&D programs based on different approaches have been launched at a growing number of institutes and companies (AES, Beijing University, BESSY, BNL, DESY, FZD, TJNAF, Niowave, NPS, Wisconsin University). Substantial progress was achieved in recent years and the first long term ...

  11. Conserved hemopoietic transcription factor Cg-SCL delineates hematopoiesis of Pacific oyster Crassostrea gigas.

    Science.gov (United States)

    Song, Xiaorui; Wang, Hao; Chen, Hao; Sun, Mingzhe; Liang, Zhongxiu; Wang, Lingling; Song, Linsheng

    2016-04-01

    Hemocytes are the effective immunocytes in bivalves, which have been reported to be derived from stem-like cells in gill epithelium of oyster. In the present work, a conserved haematopoietic transcription factor Tal-1/Scl (Stem Cell Leukemia) was identified in Pacific oyster (Cg-SCL), and it was evolutionarily close to the orthologs in deuterostomes. Cg-SCL was highly distributed in the hemocytes as well as gill and mantle. The hemocyte specific genes Integrin, EcSOD and haematopoietic transcription factors GATA3, C-Myb, c-kit, were down-regulated when Cg-SCL was interfered by dsRNA. During the larval developmental stages, the mRNA transcripts of Cg-SCL gradually increased after fertilization and peaked at early trochophore larvae stage (10 hpf, hours post fertilization), then sharply decreased in late trochophore larvae stage (15 hpf) before resuming in umbo larvae (120 hpf). Whole-mount immunofluorescence assay further revealed that the immunoreactivity of Cg-SCL appeared in blastula larvae with two approximate symmetric spots, and this expression pattern lasted in gastrula larvae. By trochophore, the immunoreactivity formed a ring around the dorsal region and then separated into two remarkable spots at the dorsal side in D-veliger larvae. After bacterial challenge, the mRNA expression levels of Cg-SCL were significantly up-regulated in the D-veliger and umbo larvae, indicating the available hematopoietic regulation in oyster larvae. These results demonstrated that Cg-SCL could be used as haematopoietic specific marker to trace potential developmental events of hematopoiesis during ontogenesis of oyster, which occurred early in blastula stage and maintained until D-veliger larvae.

  12. Scl binds to primed enhancers in mesoderm to regulate hematopoietic and cardiac fate divergence.

    Science.gov (United States)

    Org, Tõnis; Duan, Dan; Ferrari, Roberto; Montel-Hagen, Amelie; Van Handel, Ben; Kerényi, Marc A; Sasidharan, Rajkumar; Rubbi, Liudmilla; Fujiwara, Yuko; Pellegrini, Matteo; Orkin, Stuart H; Kurdistani, Siavash K; Mikkola, Hanna Ka

    2015-03-12

    Scl/Tal1 confers hemogenic competence and prevents ectopic cardiomyogenesis in embryonic endothelium by unknown mechanisms. We discovered that Scl binds to hematopoietic and cardiac enhancers that become epigenetically primed in multipotent cardiovascular mesoderm, to regulate the divergence of hematopoietic and cardiac lineages. Scl does not act as a pioneer factor but rather exploits a pre-established epigenetic landscape. As the blood lineage emerges, Scl binding and active epigenetic modifications are sustained in hematopoietic enhancers, whereas cardiac enhancers are decommissioned by removal of active epigenetic marks. Our data suggest that, rather than recruiting corepressors to enhancers, Scl prevents ectopic cardiogenesis by occupying enhancers that cardiac factors, such as Gata4 and Hand1, use for gene activation. Although hematopoietic Gata factors bind with Scl to both activated and repressed genes, they are dispensable for cardiac repression, but necessary for activating genes that enable hematopoietic stem/progenitor cell development. These results suggest that a unique subset of enhancers in lineage-specific genes that are accessible for regulators of opposing fates during the time of the fate decision provide a platform where the divergence of mutually exclusive fates is orchestrated.

  13. Analysis and Measurement of the Transfer Matrix of a 9-cell 1.3-GHz Superconducting Cavity

    Energy Technology Data Exchange (ETDEWEB)

    Halavanau, A. [Fermilab; Eddy, N. [Fermilab; Edstrom, D. [Fermilab; Harms, E. [Fermilab; Lunin, A. [Fermilab; Piot, P. [Fermilab; Romanov, A. [Fermilab; Ruan, J. [Fermilab; Solyak, N. [Fermilab; Shiltsev, V. [Fermilab

    2017-01-27

    Superconducting linacs are capable of producing intense, stable, high-quality electron beams that have found widespread applications in science and industry. The 9-cell 1.3-GHz superconducting standing-wave accelerating RF cavity originally developed for $e^+/e^-$ linear-collider applications [B. Aunes, {\\em et al.} Phys. Rev. ST Accel. Beams {\\bf 3}, 092001 (2000)] has been broadly employed in various superconducting-linac designs. In this paper we discuss the transfer matrix of such a cavity and present its measurement performed at the Fermilab Accelerator Science and Technology (FAST) facility. The experimental results are found to be in agreement with analytical calculations and numerical simulations.

  14. SRF and RF systems for LEReC Linac

    Energy Technology Data Exchange (ETDEWEB)

    Belomestnykh, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., NY (United States); Ben-Zvi, I. [Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., NY (United States); Brutus, J. C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Fedotov, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); McIntyre, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Polizzo, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Smith, K. [Brookhaven National Lab. (BNL), Upton, NY (United States); Than, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Tuozzolo, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Veshcherevich, V. [Cornell Univ., Ithaca, NY (United States); Wu, Q. [Brookhaven National Lab. (BNL), Upton, NY (United States); Xiao, B. [Brookhaven National Lab. (BNL), Upton, NY (United States); Xu, W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Zaltsman, A. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-05-03

    The Low Energy RHIC electron Cooling (LEReC) is under development at BNL to improve RHIC luminosity at low energies. It will consist of a short electron linac and two cooling sections, one for blue and one for yellow rings. For the first stage of the project, LEReC-I, we will install a 704 MHz superconducting RF cavity and three normal conducting cavities operating at 9 MHz, 704 MHz and 2.1 GHz. The SRF cavity will boost the electron beam energy up to 2 MeV. The warm cavities will be used to correct the energy spread introduced in the SRF cavity. The paper describes layouts of the SRF and RF systems, their parameters and status.

  15. A 300-nm compact mm-wave linac FEL design

    Energy Technology Data Exchange (ETDEWEB)

    Nassiri, A.; Kustom, R.L.; Kang, Y.W. [Argonne National Lab., IL (United States)

    1995-12-31

    Microfabrication technology offers an alternative method for fabricating precision, miniature-size components suitable for use in accelerator physics and commercial applications. The original R&D work at Argonne, in collaboration with the University of Illinois at Chicago, has produced encouraging results in the area of rf accelerating structure design, optical and x-ray masks production, deep x-ray lithography (LIGA exposures), and precision structural alignments. In this paper we will present a design study for a compact single pass mm-linac FEL to produce short wavelength radiation. This system will consists of a photocathode rf gun operated at 30 GHz, a 50-MeV superconducting constant gradient structure operated at 60 GHz, and a microundulator with 1-mm period. Initial experimental results on a scale model rf gun and microundulator will be presented.

  16. Beam tests on a proton linac booster for hadron therapy

    CERN Document Server

    De Martinis, C; Berra, P; Birattari, C; Calabretta, L; Crandall, K; Giove, D; Masullo, M R; Mauri, M; Rosso, E; Rovelli, A; Serafini, L; Szeless, Balázs; Toet, D Z; Vaccaro, Vittorio G; Weiss, M; Zennaro, R

    2002-01-01

    LIBO is a 3 GHz modular side-coupled proton linac booster designed to deliver beam energies up to 200 MeV, as required for the therapy of deep seated tumours. The injected beam of 50 to 70 MeV is produced by a cyclotron like those in several hospitals and research institutes. A full-scale prototype of the first module with an input/output energy of 62/74 MeV, respectively, was designed and built in 1999 and 2000. Full power RF tests were carried out successfully at CERN using a test facility at LIL at the end of the year 2000. In order to prove the feasibility of the acceleration process, an experimental setup with this module was installed at the INFN Laboratorio Nazionale del Sud (LNS) in Catania during 2001. The superconducting cyclotron provided the 62 MeV test beam. A compact solid-state RF modulator with a 4 MW klystron, made available by IBA-Scanditronix, was put into operation to power the linac. In this paper the main features of the accelerator are reviewed and the experimental results obtained duri...

  17. High-Current Energy-Recovering Electron Linacs

    Energy Technology Data Exchange (ETDEWEB)

    Nikolitsa Merminga; David Douglas; Geoffrey Krafft

    2003-12-01

    The use of energy recovery provides a potentially powerful new paradigm for generation of the charged particle beams used in synchrotron radiation sources, high-energy electron cooling devices, electron-ion colliders, and other applications in photon science and nuclear and high-energy physics. Energy-recovering electron linear accelerators (called energy-recovering linacs, or ERLs) share many characteristics with ordinary linacs, as their six-dimensional beam phase space is largely determined by electron source properties. However, in common with classic storage rings, ERLs possess a high average-current-carrying capability enabled by the energy recovery process, and thus promise similar efficiencies. The authors discuss the concept of energy recovery and its technical challenges and describe the Jefferson Lab (JLab) Infrared Demonstration Free-Electron Laser (IR Demo FEL), originally driven by a 3548-MeV, 5-mA superconducting radiofrequency (srf) ERL, which provided the most substantial demonstration of energy recovery to date: a beam of 250 kW average power. They present an overview of envisioned ERL applications and a development path to achieving the required performance. They use experimental data obtained at the JLab IR Demo FEL and recent experimental results from CEBAF-ERL GeV-scale, comparatively low-current energy-recovery demonstration at JLab to evaluate the feasibility of the new applications of high-current ERLs, as well as ERLs' limitations and ultimate performance.

  18. Phase control system for SSRF linac

    Institute of Scientific and Technical Information of China (English)

    YIN Chongxian; YU Luyang; LIU Dekang

    2008-01-01

    The design of phase control system in Shanghai Synchrotron Radiation Facility (SSRF) linac is presented in this paper. And digital phase detecting algorithm, the key for phase control system, is fully described. The testing results for phase control system in 100MeV linac are discussed in detail.

  19. Superconducting accelerating structures for very low velocity ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Xu, J.; Shepard, K.W.; Ostroumov, P.N.; Fuerst, J.D.; Waldschmidt, G.; /Argonne; Gonin, I.V.; /Fermilab

    2008-01-01

    This paper presents designs for four types of very-low-velocity superconducting accelerating cavity capable of providing several MV of accelerating potential per cavity, and suitable for particle velocities in the range 0.006 < v/c < 0.06. Superconducting TEM-class cavities have been widely applied to CW acceleration of ion beams. SC linacs can be formed as an array of independently-phased cavities, enabling a variable velocity profile to maximize the output energy for each of a number of different ion species. Several laboratories in the US and Europe are planning exotic beam facilities based on SC linacs. The cavity designs presented here are intended for the front-end of such linacs, particularly for the post-acceleration of rare isotopes of low charge state. Several types of SC cavities have been developed recently to cover particle velocities above 0.06c. Superconducting four-gap quarter-wave resonators for velocities 0.008 < {beta} = v/c < 0.05 were developed about two decades ago and have been successfully operated at the ATLAS SC linac at Argonne National Laboratory. Since that time, progress in simulation tools, cavity fabrication and processing have increased SC cavity gradients by a factor of 3-4. This paper applies these tools to optimize the design of a four-gap quarter-wave resonator for exotic beam facilities and other low-velocity applications.

  20. Superconducting accelerating structures for very low velocity ion beams

    Directory of Open Access Journals (Sweden)

    J. Xu

    2008-03-01

    Full Text Available This paper presents designs for four types of very-low-velocity superconducting (SC accelerating cavity capable of providing several MV of accelerating potential per cavity, and suitable for particle velocities in the range 0.006Superconducting TEM-class cavities have been widely applied to cw acceleration of ion beams. SC linacs can be formed as an array of independently phased cavities, enabling a variable velocity profile to maximize the output energy for each of a number of different ion species. Several laboratories in the U.S. and Europe are planning exotic beam facilities based on SC linacs. The cavity designs presented here are intended for the front end of such linacs, particularly for the postacceleration of rare isotopes of low charge state. Several types of SC cavities have been developed recently to cover particle velocities above 0.06c. Superconducting four-gap quarter-wave resonators for velocities 0.008<β=v/c<0.05 were developed about two decades ago and have been successfully operated at the ATLAS SC linac at Argonne National Laboratory. Since that time, progress in simulation tools, cavity fabrication, and processing have increased SC cavity gradients by a factor of 3–4. This paper applies these tools to optimize the design of a four-gap quarter-wave resonator for exotic beam facilities and other low-velocity applications.

  1. High gradient linac for proton therapy

    Directory of Open Access Journals (Sweden)

    S. Benedetti

    2017-04-01

    Full Text Available Proposed for the first time almost 30 years ago, the research on radio frequency linacs for hadron therapy experienced a sparkling interest in the past decade. The different projects found a common ground on a relatively high rf operating frequency of 3 GHz, taking advantage of the availability of affordable and reliable commercial klystrons at this frequency. This article presents for the first time the design of a proton therapy linac, called TULIP all-linac, from the source up to 230 MeV. In the first part, we will review the rationale of linacs for hadron therapy. We then divided this paper in two main sections: first, we will discuss the rf design of the different accelerating structures that compose TULIP; second, we will present the beam dynamics design of the different linac sections.

  2. Cloning and analysis of SCL7 gene from Populus euphratica%胡杨SCL7基因及其启动子片段的克隆与分析

    Institute of Scientific and Technical Information of China (English)

    马洪双; 夏新莉; 尹伟伦

    2011-01-01

    根据拟南芥SCL7基因序列,以杨树基因组数据库为背景克隆得到了胡杨胁迫诱导基因SCL7全长及其启动子片段,所得基因命名为PeSCL7.序列分析表明:该基因的开放阅读框1 767 bp,编码588个氨基酸,该基因不含内含子.同源性比对发现该基因属于GRAS/SCL蛋白家族中SCL4/7分支;半定量RT-PCR结果显示,PeSCL7的表达受到多种逆境胁迫的诱导,且当胁迫处理3 h时表达量达到最大值;对器官表达特异性进行分析,发现PeSCL7在胡杨的根、茎、叶中均有表达.克隆得到的胡杨PeSCL7启动子序列长968 bp,包含可能与干旱胁迫、病害胁迫等应答元件.%To characterize the function of SCL7 in Populus euphratica, we cloned the full-length PeSCL7 gene and promoter region based on the AtSCL7 sequence of Arabidopsis and the Populus database. DNA sequence analysis showed that the PeSCL7 gene contained an open reading frame of 1 767 bp long without intron and encoded a 588 amino acid polypeptide. Similarity analysis showed that it belonged to the SCL4/7 branch of GRAS/SCL family. RT-PCR analysis revealed that the PeSCL7 could be induced by various stresses and the expression reached a maximum after 3 hrs of induction. PeSCL7 was detected in leaves, stems and roots in P. euphratica via the analysis on the organ-specific expression. The PeSCL7 promoter sequence, about 968 bp in length, contained many stress-responsive cis-acting elements, i.e. ,ABRE, MYB and WRKY core sequences. The results indicate that the PeSCL7 gene may play a significant role in stress responses of P. euphratica.

  3. Novel Linac Structures For Low-Beta Ions And For Muons

    Science.gov (United States)

    Kurennoy, Sergey S.

    2011-06-01

    Development of two innovative linacs is discussed. (1) High-efficiency normal-conducting accelerating structures for ions with beam velocities in the range of a few percent of the speed of light. Two existing accelerator technologies—the H-mode resonator cavities and transverse beam focusing by permanent-magnet quadrupoles (PMQ)—are merged to create efficient structures for light-ion beams of considerable currents. The inter-digital H-mode accelerator with PMQ focusing (IH-PMQ) has the shunt impedance 10-20 times higher than the standard drift-tube linac. Results of the combined 3-D modeling for an IH-PMQ accelerator tank—electromagnetic computations, beam-dynamics simulations, and thermal-stress analysis—are presented. H-PMQ structures following a short RFQ accelerator can be used in the front end of ion linacs or in stand-alone applications like a compact mobile deuteron-beam accelerator up to a few MeV. (2) A large-acceptance high-gradient linac for accelerating low-energy muons in a strong solenoidal magnetic field. When a proton beam hits a target, many low-energy pions are produced almost isotropically, in addition to a small number of high-energy pions in the forward direction. We propose to collect and accelerate copious muons created as the low-energy pions decay. The acceleration should bring muons to a kinetic energy of ˜200 MeV in about 10 m, where both an ionization cooling of the muon beam and its further acceleration in a superconducting linac become feasible. One potential solution is a normal-conducting linac consisting of independently fed 0-mode RF cavities with wide apertures closed by thin metal windows or grids. The guiding magnetic field is provided by external superconducting solenoids. The cavity choice, overall linac design considerations, and simulation results of muon acceleration are presented. Potential applications range from basic research to homeland defense to industry and medicine.

  4. Novel linac structures for low-beta ions and for muons

    Energy Technology Data Exchange (ETDEWEB)

    Kurennoy, Sergey S [Los Alamos National Laboratory

    2010-01-01

    Development of two innovative linacs is discussed. (1) High-efficiency normal-conducting accelerating structures for ions with beam velocities in the range of a few percent of the speed of light. Two existing accelerator technologies - the H-mode resonator cavities and transverse beam focusing by permanent-magnet quadrupoles (PMQ) - are merged to create efficient structures for light-ion beams of considerable currents. The inter-digital H-mode accelerator with PMQ focusing (IH-PMQ) has the shunt impedance 10-20 times higher than the standard drift-tube linac. Results of the combined 3-D modeling for an IH-PMQ accelerator tank - electromagnetic computations, beam-dynamics simulations, and thermal-stress analysis - are presented. H-PMQ structures following a short RFQ accelerator can be used in the front end of ion linacs or in stand-alone applications like a compact mobile deuteron-beam accelerator up to a few MeV. (2) A large-acceptance high-gradient linac for accelerating low-energy muons in a strong solenoidal magnetic field. When a proton beam hits a target, many low-energy pions are produced almost isotropically, in addition to a small number of high-energy pions in the forward direction. We propose to collect and accelerate copious muons created as the low-energy pions decay. The acceleration should bring muons to a kinetic energy of {approx}200 MeV in about 10 m, where both an ionization cooling of the muon beam and its further acceleration in a superconducting linac become feasible. One potential solution is a normal-conducting linac consisting of independently fed O-mode RF cavities with wide apertures closed by thin metal windows or grids. The guiding magnetic field is provided by external superconducting solenoids. The cavity choice, overall linac design considerations, and simulation results of muon acceleration are presented. Potential applications range from basic research to homeland defense to industry and medicine.

  5. Superconducting electronics

    NARCIS (Netherlands)

    Rogalla, Horst

    1994-01-01

    During the last decades superconducting electronics has been the most prominent area of research for small scale applications of superconductivity. It has experienced quite a stormy development, from individual low frequency devices to devices with high integration density and pico second switching

  6. Dark current and radiation shielding studies for the ILC main linac

    Energy Technology Data Exchange (ETDEWEB)

    Mokhov, Nikolai V. [Fermilab; Rakhno, I. L. [Fermilab; Solyak, N. A. [Fermilab; Sukhanov, A. [Fermilab; Tropin, I. S. [Fermilab

    2016-12-05

    Electrons of dark current (DC), generated in high-gradient superconducting RF cavities (SRF) due to field emission, can be accelerated up to very high energies—19 GeV in the case of the International Linear Collider (ILC) main linac—before they are removed by focusing and steering magnets. Electromagnetic and hadron showers generated by such electrons can represent a significant radiation threat to the linac equipment and personnel. In our study, an operational scenario is analysed which is believed can be considered as the worst case scenario for the main linac regarding the DC contribution to the radiation environment in the main linac tunnel. A detailed modelling is performed for the DC electrons which are emitted from the surface of the SRF cavities and can be repeatedly accelerated in the high-gradient fields in many SRF cavities. Results of MARS15 Monte Carlo calculations, performed for the current main linac tunnel design, reveal that the prompt dose design level of 25 μSv/hr in the service tunnel can be provided by a 2.3-m thick concrete wall between the main and service ls.

  7. A Recirculating Linac-Based Facility for Ultrafast X-Ray Science

    Energy Technology Data Exchange (ETDEWEB)

    J. N. Corlett; W. A. Barletta; S. DeSantis; L. Doolittle; W. M. Fawley; M.A. Green; P. Heimann; S. Leone; S. Lidia; D. Li; A. Ratti; K. Robinson; R. Schoenlein; J. Staples; W. Wan; R. Wells; A.Wolski; A. Zholents; F. Parmigiani; M. Placidi; W. Pirkl; R. A. Rimmer; S. Wang

    2003-05-01

    We present an updated design for a proposed source of ultra-fast synchrotron radiation pulses based on a recirculating superconducting linac [1,2], in particular the incorporation of EUV and soft x-ray production. The project has been named LUX--Linac-based Ultrafast X-ray facility. The source produces intense x-ray pulses with duration of 10-100 fs at a 10 kHz repetition rate, with synchronization of 10's fs, optimized for the study of ultra-fast dynamics. The photon range covers the EUV to hard x-ray spectrum by use of seeded harmonic generation in undulators, and a specialized technique for ultra-short pulse photon production in the 1-10 keV range. High brightness rf photocathodes produce electron bunches which are optimized either for coherent emission in free electron lasers, or to provide a large x/y emittance ration and small vertical emittance which allows for manipulation to produce short-pulse hard x-rays. An injector linac accelerates the beam to 120 MeV, and is followed by f our passes through a 600-720 MeV recirculating linac. We outline the major technical components of the proposed facility.

  8. A recirculating linac-based facility for ultrafast X-ray science

    Energy Technology Data Exchange (ETDEWEB)

    Corlett, J.N; Barletta, W.A.; DeSantis, S.; Doolittle, L.; Fawley, W.M.; Green, M.A.; Heimann, P.; Leone, S.; Lidia, S.; Li, D.; Ratti, A.; Robinson, K.; Schoenlein, R.; Staples, J.; Wan, W.; Wells, R.; Wolski, A.; Zholents, A.; Placidi, M.; Pirkl, W.; Parmigiani, F.

    2003-05-06

    We present an updated design for a proposed source of ultra-fast synchrotron radiation pulses based on a recirculating superconducting linac, in particular the incorporation of EUV and soft x-ray production. The project has been named LUX - Linac-based Ultrafast X-ray facility. The source produces intense x-ray pulses with duration of 10-100 fs at a 10 kHz repetition rate, with synchronization of 10 s fs, optimized for the study of ultra-fast dynamics. The photon range covers the EUV to hard x-ray spectrum by use of seeded harmonic generation in undulators, and a specialized technique for ultra-short-pulse photon production in the 1-10 keV range. High-brightness rf photocathodes produce electron bunches which are optimized either for coherent emission in free-electron lasers, or to provide a large x/y emittance ration and small vertical emittance which allows for manipulation to produce short-pulse hard x-rays. An injector linac accelerates the beam to 120 MeV, and is followed by four passes through a 600-720 MeV recirculating linac. We outline the major technical components of the proposed facility.

  9. Greenvec Game for Skin Conductivity Level (SCL Biofeedback Performance Simulator Using Galvanic Skin Response (GSR Sensor

    Directory of Open Access Journals (Sweden)

    A.Noraziah

    2015-02-01

    Full Text Available The increasing fame of biofeedback game has brought convenience to human life. More and more people rely on biofeedback game as an alternative medical treatment to overcome their stress problems. GreenVec Biofeedback Game (GVBG is a biofeedback game-based application that able to measure the skin conductivity of the player with an integration of Galvanic Skin Response (GSR sensor. The measurement of the skin conductivity is crucial as an indicator for human meditation improvement in terms of stress control. In addition, GVBG spread awareness on global green technology issues, specifically about the Electric Vehicles (EV topics to all users throughout the game process. The measured Skin Conductivity Level (SCL corresponds to the player’s awareness of the green EV through the GVBG Simulator. Furthermore, GVBGsimulates the biofeedback performance through the measured SCL. It creates a short report on the player’s SCL based on the GSR sensor data and the game results at the end of the game session. From the results, the awareness on the EV is high when the SCL is high, whereas the awareness on the EV is low when the SCL is low. Therefore, GVBG Simulator helps users to train accordingly in order to reduce stress while at the same time gain awareness on the green technology issues with EV.

  10. Distinct Functions of Different scl Isoforms in Zebrafish Definitive Hematopoietic Stem Cell Initiation and Maintenance

    Science.gov (United States)

    Lan, Yahui

    2011-07-01

    The establishment of entire blood system relies on the multi-potent hematopoietic stem cells (HSCs), thus identifying the molecular mechanism in HSC generation is of importance for not only complementing the fundamental knowledge in stem cell biology, but also providing insights to the regenerative therapies. Recent researches have documented the formation of nascent HSCs through a direct transition from ventral aortic endothelium, named as endothelial hematopoietic transition (EHT) process. However, the precise genetic program engaged in this process remains largely elusive. The transcription factor scl plays pivotal and conserved roles in embryonic and adult hematopoiesis from teleosts to mammals. Our lab have previously identified a new truncated scl isoform, scl-beta, which is indispensible for the specification of HSCs in the ventral wall of dorsal aorta (VDA), the zebrafish equivalent of mammalian fetal hematopoietic organ. Here we observe that, by combining time-lapse confocal imaging of transgenic zebrafish and genetic epistasis analysis, scl-beta is expressed in a subset of ventral aortic endothelial cells and critical for their forthcoming transformation to hemogenic endothelium; in contrast, runx1 is required downstream to govern the successful egress of the hemogenic endothelial cells to become naive HSCs. In addition, the traditional known full-length scl-alpha isoform is firstly evidenced to be required for the maintenance or survival of newly formed HSCs in VDA. Collectively our data has established the genetic hierarchy controlling discrete steps in the consecutive process of HSC formation from endothelial cells and further development in VDA.

  11. Energy-Recovery Linacs for Commercial Radioisotope Production

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Rolland Paul [Muplus, Inc., Newport News, VA (United States)

    2016-11-19

    Most radioisotopes are produced by nuclear reactors or positive ion accelerators, which are expensive to construct and to operate. Photonuclear reactions using bremsstrahlung photon beams from less-expensive electron linacs can generate isotopes of critical interest, but much of the beam energy in a conventional electron linac is dumped at high energy, making unwanted radioactivation. The largest part of this radioactivation may be completely eliminated by applying energy recovery linac technology to the problem with an additional benefit that the energy cost to produce a given amount of isotope is reduced. Consequently, a Superconducting Radio Frequency (SRF) Energy Recovery Linac (ERL) is a path to a more diverse and reliable domestic supply of short-lived, high-value, high-demand isotopes at a cost lower than that of isotopes produced by reactors or positive-ion accelerators. A Jefferson Lab approach to this problem involves a thin photon production radiator, which allows the electron beam to recirculate through rf cavities so the beam energy can be recovered while the spent electrons are extracted and absorbed at a low enough energy to minimize unwanted radioactivation. The thicker isotope photoproduction target is not in the beam. MuPlus, with Jefferson Lab and Niowave, proposed to extend this ERL technology to the commercial world of radioisotope production. In Phase I we demonstrated that 1) the ERL advantage for producing radioisotopes is at high energies (~100 MeV), 2) the range of acceptable radiator thickness is narrow (too thin and there is no advantage relative to other methods and too thick means energy recovery is too difficult), 3) using optics techniques developed under an earlier STTR for collider low beta designs greatly improves the fraction of beam energy that can be recovered (patent pending), 4) many potentially useful radioisotopes can be made with this ERL technique that have never before been available in significant commercial quantities

  12. A Comparative Study of SCL-90 and Self-rated Health Measurement Scale in College Students%SCL-90与SRHMS用于大学生心理健康测评的结果比较研究

    Institute of Scientific and Technical Information of China (English)

    许毅; 薛志敏

    2003-01-01

    Objective: To explore the interrelated relationship of the resaots of SCL - 90 and self- rated health measurement scale (SRHMS) used in college students . Methods: 569 college students were assessed by the SCL- 90 and SRHMS. Results:All factor scores of SCL- 90 in college students were significantly higher than those of nation - wide young population. The stu-dents .with fewer mental symptoms showed significantly higher health level in SRHMS, Conlusion: The scores of SCL - 90 and SRHMS in assessing college students'' mental health levels had higher correspondentce,

  13. Development of high gradient IH linac

    Science.gov (United States)

    Isokawa, K.; Hattori, T.; Sasa, K.; Ito, T.; Hayashizaki, N.; Majima, S.; Osvath, E.; Dudu, D.; Yamada, S.

    We have studied Interdigital-H (IH)-type structures for application in heavy-ion inertial fusion (HIF) and other projects, at the Tokyo Institute of Technology (TIT). We have developed an IH linac with a high acceleration rate. It makes use of the fact that IH linacs have 5-10 times as high shunt impedance as Alvarez and RFQs in low and middle regions of energy [1-5]. We calculated trajectories of particles and made experiments by model cavities. Now an IH linac that we call high gradient IH linac is under construction. The calculated result of particle dynamics is that the transverse acceptance and an acceleration rate of this linac are 113π mm mrad and 5.5 MV/m, respectively. This linac is able to accelerate particles with a charge to mass ratio ( q/ A) greater than 1/16 from 219 keV/u up to 600 keV/u. The cavity length of this linac is 1120 mm. The frequency is 81 MHz.

  14. 25th anniversary for Linac-2

    CERN Multimedia

    2003-01-01

    On Friday, 3 October 2003, the Linac team celebrated a quarter century of successful operation of one of its linear accelerators: Linac-2, the proton workhorse of the CERN accelerator complex. Linac-2, CERN's linear proton accelerator, has now been running for 25 years - ample reason for a small celebration. About 30 members of the original team (10 of the initially more than 50 are still working at CERN), and other CERN personnel met on 3 October 2003. Linac-2 is the first link in the accelerator chain Linac-2 - PS Booster - PS - SPS and eventually LHC. Beams from Linac-2 are used after further acceleration in the CERN complex for SPS fixed target physics; for antiproton production for the Antiproton Decelerator (AD); for test beams in the East Experimental Hall and in the PS; for nuclear physics at ISOLDE; for LHC test beams and in the past for both ISR physics and Antiproton production (AA/AC) and test beams in LEAR. Linac-2 was built to obtain higher intensities and better stability than with ...

  15. Analysis on SCL-90 Testing Results of 4486 Aircrew%4486名空勤人员SCL-90测查结果分析

    Institute of Scientific and Technical Information of China (English)

    刘晓鹏; 邢军; 洪威; 徐乐乐

    2012-01-01

    Objective To study the mental health status of the aircrew, and supply reference for better psychological services. Methods Symptom Checklist 90 (SCL-90) was applied on 4486 aircrews by DXC-5 testing system. A total of 4420 validated questionnaires were acqureied. Results The SCL-90 factor scores, number of positive items, and total score of the aircrew were lower than those of the military norm (P0. 05). Taking the total score and number of positive items as the screening indicator, the positive detection rate since 2006 showed a decreasing trend. The rate with number of positive items ≥ 43 was 21. 61 % in 2006 and 8. 79% in 2011. The rate of SCL-90 total score ≥ 160 was 16. 54% in 2006 and 6. 64% in 2011. The SCL-90 factor scores, number of positive items and total score in 2011 were all lower than those in 2006 (P<0. 001). Conclusion The mental health sautus of the aircrew is better than that of the military norm and national norm and improved in recent years.%目的 了解空勤人员群体心理健康状况及变化趋势,为更好的开展心理服务提供参考依据.方法 使用DXC系列型多项群体心理测试系统(DXC-5),采用症状自评量表(Symptom Checklist 90,SCL-90),对2006/2011年疗养的4486名空勤人员实施群体测验,有效问卷4420份.结果 空勤人员群体在SCL-90各因子分、阳性项目数及总分上均低于军入常模(P<0.001).空勤人员群体在躯体化、敌意、精神病性因子分上高于全国常模(P<0.001),其他因子分、总分均低于全国常模(P<0.05,或P<0.001),在阳性项目数上无统计学差异(P>0.05).以总分和阳性项目数为筛查指标,2006年以来阳性检出率均呈现递减的趋势.阳性项目数≥43项,2006年度为21.61%,2011年为8.79%.SCL-90总分≥160分,2006年度为16.54%,2011年降至6.64%.2011年度SCL-90各因子分、阳性项目数及总分均低于2006年(P<0.001).结论 空勤人员群体的心理健康状况好于军人常模及全

  16. BEPCII Injector Linac Upgrade and Beam Instabilities

    Institute of Scientific and Technical Information of China (English)

    WANG Shu-Hong; GENG Zhe-Qiao; PEI Shi-Lun; DENG Bing-Lin; CHEN Zhi-Bi; PEI Guo-Xi; CHI Yun-Long; CHEN Yan-Wei; CAO Jian-She; KONG Xiang-Cheng; ZHAO Feng-Li; HOU Mi; LIU Wei-Bin

    2008-01-01

    The upgrade project of the Beijing Electron Positron Collider (BEPCII) and its injector linac is working well.The linac upgrade aims at a higher injection rate of 50 mA/min into the storage ring,which requires an injected beam with low emittance,low energy spread and high beam orbit and energy stabilities. This goal is finally reached recently by upgrading the linac components and by dealing with rich and practical beam physics,which are described in this study.

  17. First operation of ATLAS using the PII linac and a comparison to tandem injection

    Energy Technology Data Exchange (ETDEWEB)

    Pardo, R.C.; Bollinger, L.M.; Billquist, P.J.; Bogaty, J.M.; Clifft, B.E.; Markovich, P.; Munson, F.H.; Shepard, K.W.; Zinkann, G.P.

    1991-12-31

    The ATLAS Positive Ion Injector (PII) is designed to replace the tandem injector for the ATLAS heavy-ion facility. When the PII project is complete, ATLAS will be able to accelerate all ions through uranium to energies above the Coulomb barrier. PII consists of an ECR ion source on a 350 kV platform and a very low-velocity superconducting linac. The PII project is nearing completion. First beam from the complete system is expected in early 1992. Beam tests and experiments using a partially completed PII linac have demonstrated that the technical design goals are being met. The results of the early beam tests and first experiments will be discussed and compared to the performance of ATLAS with tandem injection. 10 refs., 2 figs.

  18. First operation of ATLAS using the PII linac and a comparison to tandem injection

    Energy Technology Data Exchange (ETDEWEB)

    Pardo, R.C.; Bollinger, L.M.; Billquist, P.J.; Bogaty, J.M.; Clifft, B.E.; Markovich, P.; Munson, F.H.; Shepard, K.W.; Zinkann, G.P.

    1991-01-01

    The ATLAS Positive Ion Injector (PII) is designed to replace the tandem injector for the ATLAS heavy-ion facility. When the PII project is complete, ATLAS will be able to accelerate all ions through uranium to energies above the Coulomb barrier. PII consists of an ECR ion source on a 350 kV platform and a very low-velocity superconducting linac. The PII project is nearing completion. First beam from the complete system is expected in early 1992. Beam tests and experiments using a partially completed PII linac have demonstrated that the technical design goals are being met. The results of the early beam tests and first experiments will be discussed and compared to the performance of ATLAS with tandem injection. 10 refs., 2 figs.

  19. BEAM DYNAMICS STUDIES OF A HIGH-REPETITION RATE LINAC-DRIVER FOR A 4TH GENERATION LIGHT SOURCE

    Energy Technology Data Exchange (ETDEWEB)

    Ventturini, M.; Corlett, J.; Emma, P.; Papadopoulos, C.; Penn, G.; Placidi, M.; Qiang, J.; Reinsch, M.; Sannibale, F.; Steier, C.; Sun, C.; Wells, R.

    2012-05-18

    We present recent progress toward the design of a super-conducting linac driver for a high-repetition rate FEL-based soft x-ray light source. The machine is designed to accept beams generated by the APEX photo-cathode gun operating with MHz-range repetition rate and deliver them to an array of SASE and seeded FEL beamlines. We review the current baseline design and report results of beam dynamics studies.

  20. Higher-order-mode absorbers for energy recovery linac cryomodules at Brookhaven National Laboratory

    Directory of Open Access Journals (Sweden)

    H. Hahn

    2010-12-01

    Full Text Available Several future accelerator projects at Brookhaven for the Relativistic Heavy Ion Collider (RHIC are based on energy recovery linacs (ERLs with high-charge high-current electron beams. Their stable operation mandates effective higher-order-mode (HOM damping. The development of HOM dampers for these projects is pursued actively at this laboratory. Strong HOM damping was experimentally demonstrated both at room and at superconducting (SC temperatures in a prototype research and development (R&D five-cell niobium superconducting rf (SRF cavity with ferrite dampers. Two room-temperature mock-up five-cell copper cavities were used to study various damper configurations with emphasis on capacitive antenna dampers. An innovative type of ferrite damper over a ceramic break for an R&D SRF electron gun also was developed. For future SRF linacs longer cryomodules comprised of multiple superconducting cavities with reasonably short intercavity transitions are planned. In such a configuration, the dampers, located closer to the cavities, will be at cryogenic temperatures; this will impose additional constraints and complications. This paper presents the results of simulations and measurements of several damper configurations.

  1. Beam Dynamics Investigation of the 101.28 MHz IH Structure as Injector for the HIE-ISOLDE SC Linac

    CERN Document Server

    Fraser, M A; Jones, R M; Voulot, D

    2010-01-01

    The first phase of the HIE-ISOLDE project at CERN consists of a superconducting (SC) linac upgrade in order to increase the energy of post-accelerated radioactive ion beams from 2.8 MeV/u to over 10 MeV/u (for A/q = 4.5). In preparation for the upgrade, we present beam dynamics studies of the booster section of the normal conducting (NC) REX-ISOLDE linac, focused on the longitudinal development of the beam in the 101.28 MHz Interdigital H-mode Structure (IHS), employing a Combined Zero Degree Structure (KONUS), pulsing at a high gradient of over 3 MV/m. The evolution of the transverse emittance in the SC linac depends critically on the injected longitudinal phase space distribution of particles from the existing linac and, with a better understanding of the beam dynamics upstream, the performance of the upgrade can be optimised. Data taken during the commissioning phase of the REX-ISOLDE linac is analysed to understand the properties of the beam in the booster and combined with beam dynamics simulations which...

  2. The invention that is shaping Linac4

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Accelerator experts are no strangers to innovative optimizations of existing techniques and to the development of novel solutions. Sometimes, they even come up with ideas that have the potential to revolutionize the field. This is the case with the Tolerance Aligned Cantilever Mounting (TACM) system, a completely new way of supporting the drift tubes, one of the core elements of linear accelerators. The new, patent-pending technique will be implemented at Linac4.   Drift tubes in a prototype for Linac4, assembled using the new TACM technology. “Assemble and adjust” – that was the technique used to build drift-tube linacs before the arrival of the TACM. Now, the inventors’ motto has become ‘adjust and assemble’. The inversion of these two words represents a real revolution for people working in the field. “The drift tubes are a critical element of Linac4 and they have to satisfy several requirements: they have to be mechanically ...

  3. Beam diagnostic suite for the SNS linac

    Science.gov (United States)

    Hardekopf, R. A.; Kurennoy, S. S.; Power, J. F.; Shafer, R. E.; Stovall, J. E.

    2000-11-01

    The Spallation Neutron Source (SNS) is the next-generation pulsed neutron source to be built in the United States. The accelerator chosen to produce the 2 MW beam power on the neutron-producing target is an H- linear accelerator (linac) to 1 GeV, followed by a proton accumulator ring. The ring compresses the 1 ms long beam bunches from the linac to less than 1 μs. The linac is pulsed at 60 Hz with a 6% duty factor. Stringent control of the pulse structure and stability of the high-intensity H- beam is needed to minimize beam loss in the linac and to optimize injection into the accumulator ring. This requires a set of beam diagnostics that can operate at high peak currents (˜52 mA) with high sensitivity and minimum beam interception.

  4. INR proton Linac operation and applications

    Energy Technology Data Exchange (ETDEWEB)

    Kravchuk, Leonid V. [Institute for Nuclear Research of the Russian Academy of Sciences, 7a, 60th October Anniversary Pr., Moscow 117312 (Russian Federation)]. E-mail: kravchuk@inr.ru

    2006-06-23

    The INR Proton Linear Accelerator is presently under operation for about 2400 h per year with energy about 250 MeV and average current up to 150 {mu}A. The Linac applications are mainly as follows: neutron and condensed matter research at spallation neutron source and neutron spectrometers, isotope production for medicine and industry, beam therapy. The experimental area description and the Linac operational experience are given in the paper.

  5. The LINAC4 Project at CERN

    CERN Document Server

    Arnaudon, L; Bertone, C; Body, Y; Broere, J; Brunner, O; Buzio, M; Carli, C; Caspers, F; Corso, JP; Coupard, J; Dallocchio, A; Dos Santos, N; Garoby, R; Gerigk, F; Hammouti, L; Hanke, K; Jones, M; Kozsar, I; Lettry, J; Lallement, JB; Lombardi, A; Lopez-Hernandez, LA; Maglioni, C; Mathot, S; Maury, S; Mikulec, B; Nisbet, D; Noels, C; Paoluzzi, M; Puccio, B; Raich, U; Ramberger, S; Rossi, C; Schwerg, N; Scrivens, R; Vandoni, G; Weisz, S; Vollaire, J; Vretenar, M; Zickler, T

    2011-01-01

    As the first step of a long-term programme aiming at an increase in the LHC luminosity, CERN is building a new 160 MeV H¯ linear accelerator, Linac4, to replace the ageing 50 MeV Linac2 as injector to the PS Booster (PSB). Linac4 is an 86-m long normal-conducting linac made of an H¯ source, a Radio Frequency Quadrupole (RFQ), a chopping line and a sequence of three accelerating structures: a Drift-Tube Linac (DTL), a Cell-Coupled DTL (CCDTL) and a Pi-Mode Structure (PIMS). The civil engineering has been recently completed, and construction of the main accelerator components has started with the support of a network of international collaborations. The low-energy section up to 3 MeV including a 3-m long 352 MHz RFQ entirely built at CERN is in the final construction phase and is being installed on a dedicated test stand. The present schedule foresees beam commissioning of the accelerator in the new tunnel in 2013/14; the moment of connection of the new linac to the CERN accelerator chain will depend on the L...

  6. Simulation of large acceptance LINAC for muons

    Energy Technology Data Exchange (ETDEWEB)

    Miyadera, H [Los Alamos National Laboratory; Kurennoy, S [Los Alamos National Laboratory; Jason, A J [Los Alamos National Laboratory

    2010-01-01

    There has been a recent need for muon accelerators not only for future Neutrino Factories and Muon Colliders but also for other applications in industry and medical use. We carried out simulations on a large-acceptance muon linac with a new concept 'mixed buncher/acceleration'. The linac can accept pions/muons from a production target with large acceptance and accelerate muon without any beam cooling which makes the initial section of muon-linac system very compact. The linac has a high impact on Neutrino Factory and Muon Collider (NF/MC) scenario since the 300-m injector section can be replaced by the muon linac of only 10-m length. The current design of the linac consists of the following components: independent 805-MHz cavity structure with 6- or 8-cm-radius aperture window; injection of a broad range of pion/muon energies, 10-100 MeV, and acceleration to 150 - 200 MeV. Further acceleration of the muon beam are relatively easy since the beam is already bunched.

  7. MEASUREMENT OF THE TRANSVERSE BEAM DYNAMICS IN A TESLA-TYPE SUPERCONDUCTING CAVITY

    Energy Technology Data Exchange (ETDEWEB)

    Halavanau, A. [NICADD, DeKalb; Eddy, N. [Fermilab; Edstrom, D. [Fermilab; Lunin, A. [Fermilab; Piot, P. [NICADD, DeKalb; Ruan, J. [Fermilab; Solyak, N. [Fermilab

    2016-09-26

    Superconducting linacs are capable of producing intense, ultra-stable, high-quality electron beams that have widespread applications in Science and Industry. Many project are based on the 1.3-GHz TESLA-type superconducting cavity. In this paper we provide an update on a recent experiment aimed at measuring the transfer matrix of a TESLA cavity at the Fermilab Accelerator Science and Technology (FAST) facility. The results are discussed and compared with analytical and numerical simulations.

  8. The Superconducting TESLA Cavities

    CERN Document Server

    Aune, B.; Bloess, D.; Bonin, B.; Bosotti, A.; Champion, M.; Crawford, C.; Deppe, G.; Dwersteg, B.; Edwards, D.A.; Edwards, H.T.; Ferrario, M.; Fouaidy, M.; Gall, P-D.; Gamp, A.; Gössel, A.; Graber, J.; Hubert, D.; Hüning, M.; Juillard, M.; Junquera, T.; Kaiser, H.; Kreps, G.; Kuchnir, M.; Lange, R.; Leenen, M.; Liepe, M.; Lilje, L.; Matheisen, A.; Möller, W-D.; Mosnier, A.; Padamsee, H.; Pagani, C.; Pekeler, M.; Peters, H-B.; Peters, O.; Proch, D.; Rehlich, K.; Reschke, D.; Safa, H.; Schilcher, T.; Schmüser, P.; Sekutowicz, J.; Simrock, S.; Singer, W.; Tigner, M.; Trines, D.; Twarowski, K.; Weichert, G.; Weisend, J.; Wojtkiewicz, J.; Wolff, S.; Zapfe, K.

    2000-01-01

    The conceptional design of the proposed linear electron-positron colliderTESLA is based on 9-cell 1.3 GHz superconducting niobium cavities with anaccelerating gradient of Eacc >= 25 MV/m at a quality factor Q0 > 5E+9. Thedesign goal for the cavities of the TESLA Test Facility (TTF) linac was set tothe more moderate value of Eacc >= 15 MV/m. In a first series of 27industrially produced TTF cavities the average gradient at Q0 = 5E+9 wasmeasured to be 20.1 +- 6.2 MV/m, excluding a few cavities suffering fromserious fabrication or material defects. In the second production of 24 TTFcavities additional quality control measures were introduced, in particular aneddy-current scan to eliminate niobium sheets with foreign material inclusionsand stringent prescriptions for carrying out the electron-beam welds. Theaverage gradient of these cavities at Q0 = 5E+9 amounts to 25.0 +- 3.2 MV/mwith the exception of one cavity suffering from a weld defect. Hence only amoderate improvement in production and preparation technique...

  9. VALIDITY OF THE GHQ AND SCL ANXIETY AND DEPRESSION SCALES - A COMPARATIVE-STUDY

    NARCIS (Netherlands)

    KOETER, MWJ

    1992-01-01

    This article presents the results of a comparison between the validity of the SCL anxiety, phobic anxiety and depression scales and the GHQ-28 anxiety-/insomnia and severe depression scales in a psychiatric outpatient population. Validity was studied at a categorical level with DSM-III diagnosis, an

  10. Some Relevant Aspects in the Design and Construction of a 30-62 MeV Linac Booster for Proton Therapy

    CERN Document Server

    Vaccaro, V G

    2004-01-01

    Recent results in accelerator physics showed the feasibility of a coupling scheme between a cyclotron and a linac for proton acceleration. Cyclotrons with energies up to 30 MeV, mainly devoted to radioisotopes production, are available in a large number of medical centres. This suggested to design a linac booster able to increase the proton energy up to 62 MeV as required for treating tumours like the ocular ones. In this paper we will review the rationale of the project; we will discuss the basic design of a compact 3 GHz SCL (Side Coupled Linac) with a new approach to the linac cavities. Among the many challenges of such a project one of the most interesting is the tuning of the cavities. Because the tuning can be done only after assembling the system, it is difficult to detect which cavities are responsible for the detuning: indeed the resonant behavior of single cavity is lost since the resonances merge into the resonant modes of the whole system. It is shown how, from the measured mode frequencies of the...

  11. Study of the Dynamics in a Linac Booster for Proton Therapy in the 30-62 MeV Energy Range

    CERN Document Server

    Vaccaro, Vittorio G; De Martinis, Carlo; Giove, Dario; Lanzone, S; Masullo, Maria R; Mauri, Marco; Rainò, Antonio; Variale, Vincenzo

    2005-01-01

    Recent results in accelerator physics have shown the feasibility of a coupling scheme between a cyclotron and a linac for proton acceleration. Cyclotrons with energies up to 30 MeV, mainly devoted to radioisotopes production, are available in a large number of medical centres. These two evidences have suggested the idea to study and design a linac booster able to increase the initial proton energy up to the values required for the treatment of tumors, like the ocular ones. Among the challenges in such a project one of the main ones is related to meet the requirement of having sufficient mean current for therapy from a given injection current coming from the cyclotron. In this paper we will review the rationale of the project in order to optimize the transmittance and to minimize the duty-cycle. In this frame we will discuss the basic design of a compact 3GHz linac with a new approach to the cavities used in a SCL (Side Coupled Linac) structure.

  12. Charge Stripper Effects on Beam Optics in 180-degree Bending Section of RISP Linac

    CERN Document Server

    Jang, Ji-Ho; Song, Jeong Seog

    2016-01-01

    The RAON, a superconducting linear accelerator for RISP (Rare Isotope Science Project), will use a charge stripper in order to increase the charge states of the heavy ions for effective acceleration in the higher energy part of the linac. The charge stripper affects the beam qualities by scattering when the heavy ions go through the charge stripper. Moreover we have to select and accelerate proper charge states between 77+ and 81+ for uranium beam case in order to satisfy the beam power requirement at an IF (Inflight Fragmentation) target. This work focuses on the beam optics affected by the charge stripper in the 180-dgree bending section.

  13. Free electron laser and superconductivity

    CERN Document Server

    Iwata, A

    2003-01-01

    The lasing of the first free-electron laser (FEL) in the world was successfully carried out in 1977, so the history of FELs as a light source is not so long. But FELs are now utilized for research in many scientific and engineering fields owing to such characteristics as tunability of the wavelength, and short pulse and high peak power, which is difficult utilizing a common light source. Research for industrial applications has also been carried out in some fields, such as life sciences, semiconductors, nano-scale measurement, and others. The task for the industrial use of FEL is the realization of high energy efficiency and high optical power. As a means of promoting realization, the combining of an FEL and superconducting linac is now under development in order to overcome the thermal limitations of normal-conducting linacs. Further, since tuning the wavelength is carried out by changing the magnetic density of the undulator, which is now induced by moving part of the stack of permanent magnets, there is un...

  14. Enhancing LVRT of DFIG by Using a Superconducting Current Limiter on Rotor Circuit

    Directory of Open Access Journals (Sweden)

    Flávio Oliveira

    2015-12-01

    Full Text Available This paper have studied the dynamic of a 2.0 MW Doubly Fed Induction Generator (DFIG during a severe voltage sag. Using the dynamic model of a DFIG, it was possible to determine the current, Electromagnetic Force and flux behavior during three-phase symmetrical voltage dip. Among the technologies of wind turbines the DFIG is widely employed; however, this machine is extremely susceptible to disturbances from the grid. In order to improve DFIG Low Voltage Ride-Through (LVRT, it is proposed a novel solution, using Superconducting Current Limiter (SCL in two arrangements: one, the SCL is placed between the machine rotor and the rotor side converter (RSC, and another placed in the RSC DC-link. The proposal is validated through simulation using PSCAD™/EMTDC™ and according to requirements of specific regulations. The analysis ensure that both SCL arrangements behave likewise, and are effective in decrement the rotor currents during the disturbance.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-07-01

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

  16. Design of a superconducting low beta niobium resonator

    Indian Academy of Sciences (India)

    Prakash Potukuchi; Amit Roy

    2012-04-01

    The proposed high current injector for the superconducting Linac at the InterUniversity Accelerator Centre will have several accelerating structures, including a superconducting module which will contain low beta niobium resonators. A prototype resonator for the low beta module has been designed. The resonator has been carefully modelled to optimize the electromagnetic parameters. In order to validate them, a room-temperature copper model has been built and tested. In this paper we present details of the electromagnetic design of the low beta resonator, briefly discuss the mechanical and engineering design, and present results from the measurements on the room-temperature copper model.

  17. HIE-ISOLDE CRYO-MODULE Assembly - Superconducting Solenoid

    CERN Multimedia

    Leclercq, Yann

    2016-01-01

    Assembly of the cryo-module components in SM18 cleanroom. The superconducting solenoid (housed inside its helium vessel) is cleaned, prepared then installed on the supporting frame of the cryo-module and connected to the helium tank, prior to the assembly of the RF cavities on the structure. The completed first 2 cryo-modules installed inside the HIE-ISOLDE-LINAC ready for beam operation is also shown.

  18. The Linac Coherent Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Galayda, John N

    2003-05-21

    A collaboration of scientists from SLAC, UCLA, Los Alamos National Laboratory, Brookhaven National Laboratory, and Argonne National Laboratory have proposed to build the Linac Coherent Light Source (LCLS) facility, a free-electron laser (FEL) on the SLAC site, spanning photon energies 0.8-8 keV. The laser output will be 8-10 GW with pulse lengths 230 fsec or less. The LCLS will offer unprecedented experimental opportunities in the areas of atomic physics, chemical dynamics, plasma physics, nanoscale dynamics, and biomolecular imaging. SLAC has proposed to begin engineering design of the laser in 2003, leading to project completion in 2008. The laser produces x-rays by the self-amplified spontaneous emission (SASE) process: an intense, highly collimated pulse of 14.5 GeV electrons, traveling through a 122 m-long undulator magnet system, is induced by its own synchrotron radiation to form sub-nanometer-scale bunches. The bunching process enhances the coherence and hence the intensity of the emitted synchrotron radiation. The process is analogous to the instability of a high-gain amplifier; the ''noise'' signal that seeds the instability is the shot noise in the electron beam.

  19. RNB-specific linac development

    CERN Document Server

    Ratzinger, U

    2002-01-01

    The acceleration of secondary, radioactive beams from primary beam driven ion sources provides many challenges when compared to the case of conventional ion beams. The clean separation of the specific ion species, the low beam current, the short life time of the ions as well as the needed energy variability have consequences on the layout of the accelerator. As also experiments with astrophysical relevance are performed, the energy range should go down below 1 MeV/u in some cases. Additionally, to investigate nuclear reactions around the Coulomb barrier, the beam energy should be flexible up to around 8 MeV/u. Short isotope life times below a few milliseconds do not allow for charge breeding. In these cases, low charged ions from 'simple' ion sources have to be accepted by the accelerator. Furthermore, stripping processes along the linac are excluded in case of low beam currents. Multicoincidence experiments profit a lot from cw operation of ion source and accelerators. During the last three decades, room tem...

  20. CERN Linac4. The space charge challenge

    Energy Technology Data Exchange (ETDEWEB)

    Hein, Lutz Matthias

    2013-08-06

    In the first phase of the upgrade program of the CERN accelerator complex the proton injector Linac2 will be replaced by a new, normal-conducting H-ion Linac, Linac4, allowing a significant increase of the proton flux intensity along the downstream accelerator complex. In the design of Linac4 three beam transport sections are implemented to match the beam between the different accelerator elements and to model the longitudinal pulse structure. These three beam transport sections, which are the most critical locations in terms of beam quality preservation, are in the focus of this thesis. During the work of this thesis the Low Energy Beam Transport (LEBT), which is required to match the source beam to the radiofrequency quadrupole (RFQ), has been commissioned and its beam dynamics re-constructed. The measurement campaign used to reconstruct the LEBT beam dynamics was performed with the aim to prepare the RFQ commissioning and to maximise the LEBT performance. Downstream of the Linac4 accelerator the beam is transported along a 180 m long transfer line to the Proton Synchrotron Booster (PS-Booster). The transfer line optics was studied, optimised and sections were completely re-designed. The new transfer line optics is characterised by an improved preservation of the beam emittance, higher stability of the optical solution with respect to alignment errors and field jitters of the transfer line magnets and it is matched to each of the PS-Booster injection schemes. In a concluding ''Start-To-End'' simulation based on the measured beam characteristics at the LEBT exit the beam dynamics of the downstream Linac, including the transfer line, was calculated. To minimise particle losses within acceptable emittance preservation the beam optics of the Medium Energy Beam Transport (MEBT) was adapted to the measured beam parameters. This ''Start-To-End'' simulation was performed to identify critical sections of the Linac4 beam dynamics and

  1. An Electron Bunch Compression Scheme for a Superconducting Radio Frequency Linear Accelerator Driven Light Source

    Energy Technology Data Exchange (ETDEWEB)

    C. Tennant, S.V. Benson, D. Douglas, P. Evtushenko, R.A. Legg

    2011-09-01

    We describe an electron bunch compression scheme suitable for use in a light source driven by a superconducting radio frequency (SRF) linac. The key feature is the use of a recirculating linac to perform the initial bunch compression. Phasing of the second pass beam through the linac is chosen to de-chirp the electron bunch prior to acceleration to the final energy in an SRF linac ('afterburner'). The final bunch compression is then done at maximum energy. This scheme has the potential to circumvent some of the most technically challenging aspects of current longitudinal matches; namely transporting a fully compressed, high peak current electron bunch through an extended SRF environment, the need for a RF harmonic linearizer and the need for a laser heater. Additional benefits include a substantial savings in capital and operational costs by efficiently using the available SRF gradient.

  2. RFI-Based Ion Linac Systems

    Science.gov (United States)

    Swenson, Donald A.

    A new company, Ion Linac Systems, Inc., has been formed to promote the development, manufacture, and marketing of intense, RFI-based, Ion Linac Systems. The Rf Focused Interdigital (RFI) linac structure was invented by the author while at Linac Systems, LLC. The first step, for the new company, will be to correct a flaw in an existing RFI-based linac system and to demonstrate "good transmission" through the system. The existing system, aimed at the BNCT medical application, is designed to produce a beam of 2.5 MeV protons with an average beam current of 20 mA. In conjunction with a lithium target, it will produce an intense beam of epithermal neutrons. This system is very efficient, requiring only 180 kW of rf power to produce a 50 kW proton beam. In addition to the BNCT medical application, the RFI-based systems should represent a powerful neutron generator for homeland security, defence applications, cargo container inspection, and contraband detection. The timescale to the demonstration of "good transmission" is early fall of this year. Our website is www.ionlinacs.com.

  3. The Eindhoven linac-racetrack microtron combination

    Energy Technology Data Exchange (ETDEWEB)

    Theuws, W.H.C.; Botman, J.I.M.; Hagedoorn, H.L.; Timmermans, C.J. [Tech. Univ., Eindhoven (Netherlands). Cyclotron Lab.

    1998-04-01

    The Eindhoven linac-race track microtron (RTM) combination has been designed to serve as injector for an electron storage ring. The linac is a 10 MeV travelling-wave linac (type M.E.L. SL75/10). In the RTM a 5 MeV standing-wave cavity, which is synchronized with the linac, accelerates the electron beam 13 times, such that the extraction energy is 75 MeV. The RTM end magnets are two-sector magnets tilted in their median planes, to provide strong focusing forces for optimal electron-optical properties. Closed-orbit conditions are fulfilled with the help of small correction dipoles located in the RTM drift space; the magnetic-field strengths of these correction dipoles are adjusted on the basis of beam-position measurements. Isochronous acceleration is accomplished by position- and phase-measurements. A low-cost elaborate diagnostic system will be used for efficient commissioning of the combination of the 10 MeV linac and the 10-75 MeV RTM. (orig.) 10 refs.

  4. The Eindhoven linac-racetrack microtron combination

    Science.gov (United States)

    Theuws, W. H. C.; Botman, J. I. M.; Hagedoorn, H. L.; Timmermans, C. J.

    1998-04-01

    The Eindhoven linac-race track microtron (RTM) combination has been designed to serve as injector for an electron storage ring. The linac is a 10 MeV travelling-wave linac (type M.E.L. SL75/10). In the RTM a 5 MeV standing-wave cavity, which is synchronized with the linac, accelerates the electron beam 13 times, such that the extraction energy is 75 MeV. The RTM end magnets are two-sector magnets tilted in their median planes, to provide strong focusing forces for optimal electron-optical properties. Closed-orbit conditions are fulfilled with the help of small correction dipoles located in the RTM drift space; the magnetic-field strengths of these correction dipoles are adjusted on the basis of beam-position measurements. Isochronous acceleration is accomplished by position- and phase-measurements. A low-cost elaborate diagnostic system will be used for efficient commissioning of the combination of the 10 MeV linac and the 10-75 MeV RTM.

  5. Analysis of SCL-90 Test in Higher Vocational College Freshmen%高职大学新生SCL-90的结果分析

    Institute of Scientific and Technical Information of China (English)

    王品; 陈金环; 张朝清

    2015-01-01

    本研究采用症状自评量表(SCL-90问卷),分别对2011级、2012级、2013级新入校高职大学生进行心理健康状况调查。结果表明:大学新生中度以上心理问题检出率为4.2%,主要表现为强迫、人际关系敏感、焦虑和抑郁。不同性别、不同入校年度的大学新生心理问题各异,入校新生心理问题不容忽视。%This study tested the higher vocational college fresh-men of grade 2011, 2012 and 2013 with the method of SCL-90 psychology evaluation test in this research. The results revealed that:There was 4.2 percent of students scored above 3 on one or more sub-scales. The most common mental health problems were paranoia, interpersonal sensitivity, anxiety and depression. The psychological disorders were different in sex and entrance time, so they can not be ignored every year.

  6. Beam dynamics studies in the driver LINAC pre-stripper section of the RIA facility

    Indian Academy of Sciences (India)

    E S Lessner; P N Ostroumov

    2002-12-01

    The RIA facility driver LINAC consists of about 400 superconducting (SC) independently phased rf cavities. The LINAC is designed to accelerate simultaneously several charge-state beams to generate as much as 400 kW of uranium beam power. The LINAC beam dynamics is most sensitive to the focusing and accelerating structure parameters of the pre-stripper section, where the uranium beam is accelerated from 0.17 keV/u to 9.4 MeV/u. This section is designed to accept and accelerate two charge states (28 and 29) of uranium beam from an ECR ion source. The pre-stripper section must be designed to minimize the beam emittance distortion of this two-charge-state beam. In particular, the inter-cryostat spaces must be minimized and beam parameters near transitions of the accelerating and focusing lattices must be matched carefully. Several sources of possible effective emittance growth are considered in the design of the pre-stripper section and a tolerance budget is established. Numerical beam dynamics studies include realistic electric and magnetic three-dimensional field distributions in the SC rf cavities and SC solenoids. Error effects in the longitudinal beam parameters are studied.

  7. LUX — A Recirculating Linac-based Ultrafast X-ray Source

    Science.gov (United States)

    Corlett, J. N.; Barletta, W. A.; DeSantis, S.; Doolittle, L.; Fawley, W. M.; Green, M. A.; Heimann, P.; Leone, S. R.; Lidia, S.; Li, D.; Parmigiani, F.; Ratti, A.; Robinson, K.; Schoenlein, R.; Staples, J.; Wan, W.; Wells, R.; Wilcox, R.; Wolski, A.; Zholents, A.

    2004-05-01

    We describe the design of a proposed source of ultra-fast synchrotron radiation x-ray pulses based on a recirculating superconducting linac, with an integrated array of ultrafast laser systems. The source produces x-ray pulses with duration of 10-50 fs at a 10 kHz repetition rate, with tunability from EUV to hard x-ray regimes, and optimized for the study of ultra-fast dynamics. A high-brightness rf photocathode provides electron bunches. An injector linac accelerates the beam to the 100 MeV range, and is followed by four passes through a 700 MeV recirculating linac. Ultrafast hard x-ray pulses are obtained by a combination of electron bunch manipulation, transverse temporal correlation of the electrons, and x-ray pulse compression. EUV and soft x-ray pulses as short as 10 fs are generated in a harmonic-cascade free electron laser scheme. We describe the facility major systems and peformance.

  8. Superconducting Microelectronics.

    Science.gov (United States)

    Henry, Richard W.

    1984-01-01

    Discusses superconducting microelectronics based on the Josephson effect and its advantages over conventional integrated circuits in speed and sensitivity. Considers present uses in standards laboratories (voltage) and in measuring weak magnetic fields. Also considers future applications in superfast computer circuitry using Superconducting…

  9. Cloning and expression analysis of PeSCL6 gene in Phyllostachys edulis Carr.%毛竹PeSCL6基因的克隆及其表达分析

    Institute of Scientific and Technical Information of China (English)

    陈东亮; 彭镇华; 高志民

    2014-01-01

    SCL6基因是植物保持茎端分生组织未分生状态所必需的关键基因之一。采用RT-PCR和RACE方法从毛竹(Phyllostachys edulis Carr.)中获得一个SCL6同源基因,命名为PeSCL6。该基因全长1894 bp,其中5′端非编码区60 bp,3′端非编码区211 bp,编码区1623 bp,共编码540个氨基酸。序列分析表明:PeSCL6基因编码的蛋白含有LHRI、VHIID、LHRII、PFYRE和SAW 5个保守区,属于GRAS家族蛋白;该蛋白与水稻、玉米、高粱等单子叶植物的SCL6有较高的一致性(70%以上)。实时定量PCR结果表明:PeSCL6基因为组成型表达,且在叶片中的表达丰度最高;而在即将开花之前和处于盛花期的竹株叶片中PeSCL6表达丰度明显降低,分别为幼龄竹株叶片的1%和14%。 PeSCL6基因表达的变化,意味着它可能参与毛竹由营养生长向生殖生长的转换调控。%SCL6 is one of the key genes for plant to maintain the shoot apical meristem tissue in indeterminate state. A homologue gene of SCL6 was cloned from moso bamboo ( Phyllostachys edulis Carr.) using RT-PCR and RACE methods, and named as PeSCL6. The full length of PeSCL6 was 1 894 bp including 60 bp 5′ untranslated region ( UTR) , 211 bp 3′UTR and an open reading frame of 1 623 bp, which encoded 489 amino acids. Blastp analysis indi-cated that PeSCL6 had high identities with SCL6 from monocotyledon plants ( all up to more than 70%) such as Zea mays, Oryza sativa and Sorghum bicolor. Real time PCR analysis showed that PeSCL6 expressed constitutively with the highest level in leaves of young seedlings. However, the PeSCL6 expressed much lower in the leaves at adult bamboo at just before and full blooming stages, which were only 1% and 14% of that in young seedling leaves, respectively. The changes of expression level in leaves indicated that PeSCL6 gene might be involved in the switch regulation of moso bam-boo from vegetative to reproductive growth.

  10. S-Band Loads for SLAC Linac

    Energy Technology Data Exchange (ETDEWEB)

    Krasnykh, A.; Decker, F.-J.; /SLAC; LeClair, R.; /INTA Technologies, Santa Clara

    2012-08-28

    The S-Band loads on the current SLAC linac RF system were designed, in some cases, 40+ years ago to terminate 2-3 MW peak power into a thin layer of coated Kanthal material as the high power absorber [1]. The technology of the load design was based on a flame-sprayed Kanthal wire method onto a base material. During SLAC linac upgrades, the 24 MW peak klystrons were replaced by 5045 klystrons with 65+ MW peak output power. Additionally, SLED cavities were introduced and as a result, the peak power in the current RF setup has increased up to 240 MW peak. The problem of reliable RF peak power termination and RF load lifetime required a careful study and adequate solution. Results of our studies and three designs of S-Band RF load for the present SLAC RF linac system is discussed. These designs are based on the use of low conductivity materials.

  11. Wake field effects in APT linac

    Energy Technology Data Exchange (ETDEWEB)

    Kurennoy, S.S.

    1998-12-31

    The 1.7-GeV 100-mA CW proton linac is now under design for the Accelerator Production of Tritium (APT) Project. The high current leads to stringent restrictions on allowable beam losses (<1 nA/m), that requires analyzing carefully all possible loss sources. While wake-field effects are usually considered negligible in proton linacs, the author studies these effects for the APT to exclude potential problems at such a high current. Loss factors and resonance frequency spectra of various discontinuities of the vacuum chamber are investigated, both analytically and using 2-D and 3-D simulation codes with a single bunch as well as with many bunches. Here he concentrates on two features specific to the APT linac: loss factors for the design {beta} < 1 and CW beam structure.

  12. Electro neutrons around a 12 MV Linac

    Energy Technology Data Exchange (ETDEWEB)

    Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Apdo. Postal 336, 98000 Zacatecas (Mexico); Perez L, L. H., E-mail: fermineutron@yahoo.com [Instituto Zacatecano del Tumor, A. C., Lago de la Encantada No. 294, Fracc. Lomas del Lago, Zacatecas (Mexico)

    2012-10-15

    Neutron contamination around Linacs for radiotherapy is a source of undesirable doses for the patient. The main source of these neutrons is the photonuclear reactions occurring in the Linac head and the patient body. Electrons also produce neutrons through (e, en) reactions. This reaction is known as electro disintegration and is carried out by the electron scattering that produce a virtual photon that is absorbed by the scattering nucleus producing the reaction e + A {yields} (A-1) + n + e'. In this work the electron-neutron spectrum to 100 cm from the isocenter of a 12 MV Linac has been measured using a passive Bonner spheres spectrometer in a novel procedure named Planetary mode. (Author)

  13. Stabilization Strategies for Drift Tube Linacs

    CERN Document Server

    AUTHOR|(CDS)2085420; Lamehi Rashti, Mohammad

    The average axial electric fields in drift tube linac cavities are known to be sensitive with respect to the perturbation errors. Postcoupler is a powerful stabilizer devices that is used to reduce this sensitivity of average axial field. Postcouplers are the cylindrical rod which is extended from cavity wall toward the drift tube without touching the drift tube surface. Postcouplers need to be adjusted to the right length to stabilize the average axial field. Although postcouplers are used successfully in many projects, there is no straightforward procedure for postcouplers adjustment and it has been done almost based on trial and errors. In this thesis, the physics and characteristics of postcouplers has been studied by using an equivalent circuit model and 3D finite element method calculations. Finally, a straightforward and accurate method to adjust postcouplers has been concluded. The method has been verified by using experimental measurements on CERN Linac4 drift tube linac cavities.

  14. Energy Recovery Linacs for Commercial Radioisotope Production

    Energy Technology Data Exchange (ETDEWEB)

    Sy, Amy [Jefferson Lab, Newport News, VA; Krafft, Geoffrey A. [Jefferson Lab, Newport News, VA; Johnson, Rolland [Muons, Inc., Batavia, IL; Roberts, Tom; Boulware, Chase; Hollister, Jerry

    2015-09-01

    Photonuclear reactions with bremsstrahlung photon beams from electron linacs can generate radioisotopes of critical interest. An SRF Energy Recovery Linac (ERL) provides a path to a more diverse and reliable domestic supply of short-lived, high-value, high-demand isotopes in a more compact footprint and at a lower cost than those produced by conventional reactor or ion accelerator methods. Use of an ERL enables increased energy efficiency of the complex through energy recovery of the waste electron beam, high electron currents for high production yields, and reduced neutron production and shielding activation at beam dump components. Simulation studies using G4Beamline/GEANT4 and MCNP6 through MuSim, as well as other simulation codes, will design an ERL-based isotope production facility utilizing bremsstrahlung photon beams from an electron linac. Balancing the isotope production parameters versus energy recovery requirements will inform a choice of isotope production target for future experiments.

  15. Diagnostics For Recirculating And Energy Recovered Linacs

    Energy Technology Data Exchange (ETDEWEB)

    Geoffrey A. Krafft; Jean-Claude Denard

    2002-12-18

    In this paper, the electron beam diagnostics developed for recirculating electron accelerators will be reviewed. The main novelties in dealing with such accelerators are: to have sufficient information and control possibilities for the longitudinal phase space, to have means to accurately set the recirculation path length, and to have a means to distinguish the beam passes on measurements of position in the linac proper. The solutions to these problems obtained at Jefferson Laboratory and elsewhere will be discussed. In addition, more standard instrumentation (profiling and emittance measurements) will be reviewed in the context of recirculating linacs. Finally, and looking forward, electron beam diagnostics for applications to high current energy recovered linacs will be discussed.

  16. Neutron and photon spectra in LINACs.

    Science.gov (United States)

    Vega-Carrillo, H R; Martínez-Ovalle, S A; Lallena, A M; Mercado, G A; Benites-Rengifo, J L

    2012-12-01

    A Monte Carlo calculation, using the MCNPX code, was carried out in order to estimate the photon and neutron spectra in two locations of two linacs operating at 15 and 18 MV. Detailed models of both linac heads were used in the calculations. Spectra were estimated below the flattening filter and at the isocenter. Neutron spectra show two components due to evaporation and knock-on neutrons. Lethargy spectra under the filter were compared to the spectra calculated from the function quoted by Tosi et al. that describes reasonably well neutron spectra beyond 1 MeV, though tends to underestimate the energy region between 10(-6) and 1 MeV. Neutron and the Bremsstrahlung spectra show the same features regardless of the linac voltage.

  17. PENERAPAN STUDENT CENTERED LEARNING (SCL MELALUI METODE MNEMONIK DENGAN TEKNIK ASOSIASI PADA MATA KULIAH KANJI DASAR

    Directory of Open Access Journals (Sweden)

    Linna Meilia Rasiban

    2013-10-01

    Abstract Application of student centered learning (SCL through mnemonics method and associated technique in basic Kanji (Shokyu Hyouki. The purpose of this study was to determine the effectiveness of instructional media and its influence in improving students' ability in learning basic kanji. Kanji is one important element in studying the Japanese language, but at the same time, it is the most difficult by Japanese learners. So far, in most of the kanji taught using lecture method with media-centered teaching (teacher center.  This research concerns about student difficulties in memorizing kanji meaning with emphasis on the improvement of instructional media that had been done.  The research method used was experimental method. Based on the results of this study concluded that sufficient media interactive CD helps students to memorize kanji meaning, especially when working on the exam. Keywords: SCL, mnemonics method,associated technique,basic kanji.

  18. Status of RF superconductivity at Argonne

    Energy Technology Data Exchange (ETDEWEB)

    Shepard, K.W.

    1989-01-01

    Development of a superconducting (SC) slow-wave structures began at Argonne National Laboratory (ANL) in 1971, and led to the first SC heavy-ion linac (ATLAS - the Argonne Tandem-Linac Accelerating System), which began regularly scheduled operation in 1978. To date, more than 40,000 hours of bean-on target operating time has been accumulated with ATLAS. The Physics Division at ANL has continued to develop SC RF technology for accelerating heavy-ions, with the result that the SC linac has, up to the present, has been in an almost continuous process of upgrade and expansion. It should be noted that this has been accomplished while at the same time maintaining a vigorous operating schedule in support of the nuclear and atomic physics research programs of the division. In 1987, the Engineering Physics Division at ANL began development of SC RF components for the acceleration of high-brightness proton and deuterium beams. This work has included the evaluation of RF properties of high-{Tc} oxide superconductors, both for the above and for other applications. The two divisions collaborated while they worked on several applications of RF SC, and also worked to develop the technology generally. 11 refs., 6 figs.

  19. On the Feasibility of Accelerating Deuterons in Linac4

    CERN Document Server

    Stovall, J; Garcia Tudela, M; Ramberger, S; Crandall, K

    2011-01-01

    The Linac4 normal-conducting linac is comprised of three sections, DTL, CCDTL and PIMS. It is designed to accelerate H-minus ions to a final energy of 160 MeV. The objective of this study is to investigate the feasibility of accelerating deuterons in this linac for injection into the PS Booster.

  20. Presenting the SCL model: adding value to business strategy through UCD principles

    OpenAIRE

    Moreno, M. A.; Lilley, D; Lofthouse, V.

    2014-01-01

    This paper presents the Sustainable Consumption Leveraging (SCL) Model and its toolkit, which was developed to help businesses examine their potential for enabling sustainable consumption whilst identifying areas of opportunity to improve their business model and value proposition. The paper begins by establishing the contribution of business towards sustainable consumption and sets out user-centred design (UCD) principles as a valuable approach to leverage sustainable consumption. The relati...

  1. Deuterons Acceleration in I-100 Linac

    CERN Document Server

    Antipov, Yu M; Batarin, V A; Gorin, Yu P; Davydov, V V; Maltsev, A P; Nizhegorodtsev, V V; Pilipenko, C I; Starodubrovsky, E K; Surenskii, A V; Taplyakov, V A; Troyanov, E F; Tyurin, N E

    2003-01-01

    High energy deuteron beams are of great interest for fundamental and applied researches. Creation of such beams on IHEP accelerator complex in energy range 0,1(plus-minus)35 GeV/u significantly widens the research possibili-ties with relativistic deuterons in our country. Accelerated deuterons are also à precondition for other light nuclei acceleration in IHEP. IHEP Alvarez type proton I-100 linac can be used as light ions injector. In this work the results of deuterons acceleration studies in I-100 linac are presented.

  2. 4-rod RFQ linac for ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Fujisawa, Hiroshi; Hamamoto, Nariaki; Inouchi, Yutaka [Nisshin Electric Co. Ltd., Kyoto (Japan)

    1997-03-01

    A 34 MHz 4-rod RFQ linac system has been upgraded in both its rf power efficiency and beam intensity. The linac is able to accelerate in cw operation 0.83 mA of a B{sup +} ion beam from 0.03 to 0.91 MeV with transmission of 61 %. The rf power fed to the RFQ is 29 kW. The unloaded Q-value of the RFQ has been improved approximately 61 % to 5400 by copper-plating stainless steel cooling pipes in the RFQ cavity. (author)

  3. Preinjector for Linac 1, accelerating column

    CERN Multimedia

    1974-01-01

    For a description of the Linac 1 preinjector, please see first 7403070X. High up on the wall of the Faraday cage (7403073X) is this drum-shaped container of the ion source (7403083X). It is mounted at the HV end of the accelerating column through which the ions (usually protons; many other types of ions in the course of its long history) proceed through the Faraday cage wall to the low-energy end (at ground potential) of Linac 1. The 520 kV accelerating voltage was supplied by a SAMES generator (7403074X).

  4. Scl-1013644: a CEMP-s star in the Sculptor dwarf spheroidal galaxy

    Science.gov (United States)

    Salgado, C.; Da Costa, G. S.; Yong, D.; Norris, J. E.

    2016-11-01

    Recent studies of the Milky Way and its satellites have paid special attention to the importance of carbon-enhanced metal-poor (CEMP) stars due to their involvement in Galactic formation history and their possible connection with the chemical elements originating in the first stellar generation. In an ongoing study of red giants in the Sculptor dwarf galaxy, we have discovered a star with extremely strong CN and CH molecular bands. This star, Scl-1013644, has previously been identified by Geisler et al. as a star with an enrichment in the heavy elements. Spectrum synthesis has been used to derive the carbon, nitrogen and barium abundances for Scl-1013644. Our findings are [C/Fe] = +0.8, [N/Fe] = -0.3 and [Ba/Fe] = +2.1 with the latter result consistent with the value found by Geisler et al. These results reveal Scl-1013644 as a CEMP-s star, the third such star discovered in this dwarf galaxy.

  5. The detached dust shells around the carbon AGB stars R Scl and V644 Sco

    CERN Document Server

    Maercker, Matthias; Leal-Ferreira, Marcelo M L; Olofsson, Göran; Florén, Hans-Gustav

    2014-01-01

    Detached shells are believed to be created during a thermal pulse, and constrain the time scales and physical properties of one of the main drivers of late stellar evolution. We aim at determining the morphology of the detached dust shells around the carbon AGB stars R Scl and V644 Sco, and compare this to observations of the detached gas shells. We observe the polarised, dust-scattered stellar light around these stars using the PolCor instrument mounted on the ESO 3.6m telescope. Observations were done with a coronographic mask to block out the direct stellar light. The polarised images clearly show the detached shells. Using a dust radiative transfer code to model the dust-scattered polarised light, we constrain the radii and widths of the shells to 19.5 arcsec and 9.4 arcsec for the detached dust shells around R Scl and V644 Sco, respectively. Both shells have an overall spherical symmetry and widths of approx. 2 arcsec. For R Scl we can compare the observed dust emission directly with high spatial-resolut...

  6. Scl-1013644: a CEMP-s star in the Sculptor Dwarf Spheroidal Galaxy

    CERN Document Server

    Salgado, C; Yong, D; Norris, J E

    2016-01-01

    Recent studies of the Milky Way and its satellites have paid special attention to the importance of carbon-enhanced metal-poor (CEMP) stars due to their involvement in Galactic formation history and their possible connection with the chemical elements originating in the first stellar generation. In an ongoing study of red giants in the Sculptor dwarf galaxy we have discovered a star with extremely strong CN and CH molecular bands. This star, Scl-1013644, has previously been identified by Geisler et al. (2005) as a star with an enrichment in the heavy elements. Spectrum synthesis has been used to derive the carbon, nitrogen and barium abundances for Scl-1013644. Our findings are [C/Fe] = +0.8, [N/Fe] = -0.3 and [Ba/Fe] = +2.1 with the latter result consistent with the value found by Geisler et al. (2005). These results reveal Scl-1013644 as a CEMP-s star, the third such star discovered in this dwarf galaxy.

  7. CERN Developments for 704 MHz Superconducting Cavities

    CERN Document Server

    Capatina, O; Aviles Santillana, I; Arnau Izquierdo, G; Bonomi, R; Calatroni, S; Chambrillon, J; Gerigk, F; Garoby, R; Guinchard, M; Junginger, T; Malabaila, M; Marques Antunes Ferreira, L; Mikulas, S; Parma, V; Pillon, F; Renaglia, T; Schirm, K; Tardy, T; Therasse, M; Vacca, A; Valverde Alonso, N; Vande Craen, A

    2013-01-01

    The Superconducting Proton Linac (SPL) is an R&D effort coordinated by CERN in partnership with other international laboratories. It is aiming at developing key technologies for the construction of a multi-megawatt proton linac based on state-of-the-art RF superconducting technology, which would serve as a driver in new physics facilities for neutrinos and/or Radioactive Ion Beam (RIB). Amongst the main objectives of this R&D effort, is the development of 704 MHz bulk niobium beta=1 elliptical cavities, operating at 2 K with a maximum accelerating gradient of 25 MV/m, and the testing of a string of cavities integrated in a machine-type cryomodule. The cavity together with its helium tank had to be carefully designed in coherence with the innovative design of the cryomodule. New fabrication methods have also been explored. Five such niobium cavities and two copper cavities are in fabrication. The key design aspects are discussed, the results of the alternative fabrication methods presented and the stat...

  8. Error analysis in post linac to driver linac transport beam line of RAON

    Science.gov (United States)

    Kim, Chanmi; Kim, Eun-San

    2016-07-01

    We investigated the effects of magnet errors in the beam transport line connecting the post linac to the driver linac (P2DT) in the Rare Isotope Accelerator in Korea (RAON). The P2DT beam line is bent by 180-degree to send the radioactive Isotope Separation On-line (ISOL) beams accelerated in Linac-3 to Linac-2. This beam line transports beams with multi-charge state 132Sn45,46,47. The P2DT beam line includes 42 quadrupole, 4 dipole and 10 sextupole magnets. We evaluate the effects of errors on the trajectory of the beam by using the TRACK code, which includes the translational and the rotational errors of the quadrupole, dipole and sextupole magnets in the beam line. The purpose of this error analysis is to reduce the rate of beam loss in the P2DT beam line. The distorted beam trajectories can be corrected by using six correctors and seven monitors.

  9. SCL-90 R: Distrés psicológico, género y conductas de riesgo / SCL-90 R: Psychological Distress, Gender and Risky Behaviors

    Directory of Open Access Journals (Sweden)

    Nancy Patricia Caballero Suárez

    2013-03-01

    Full Text Available Con base en una muestra probabilística de 466 estudiantes universitarios mexicanos, se explora la relación entre distrés psicológico y conductas de riesgo (consumo de sustancias, conductas sexuales, y ambas, en hombres y mujeres. Los resultados indican que el distrés psicológico presenta diferencias con mayor frecuencia en el caso de las mujeres que presentan consumo de drogas, tabaco y alcohol, o conductas que mezclan sexo y alcohol, y sexo y consumo de drogas, que en el caso de los hombres. Los hombres con actividad sexual ocasional presentan mayor distrés que quellos que no presentan esta conducta. Como punto de partida, se explora la estructura factorial del SCL-90-R, coincidiendo en los resultados con los obtenidos por investigadores de otras latitudes; al parecer, el análisis factorial no soporta la estructura propuesta por los autores del instrumento.

  10. Color superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Wilczek, F. [Institute for Advanced Study, Princeton, NJ (United States)

    1997-09-22

    The asymptotic freedom of QCD suggests that at high density - where one forms a Fermi surface at very high momenta - weak coupling methods apply. These methods suggest that chiral symmetry is restored and that an instability toward color triplet condensation (color superconductivity) sets in. Here I attempt, using variational methods, to estimate these effects more precisely. Highlights include demonstration of a negative pressure in the uniform density chiral broken phase for any non-zero condensation, which we take as evidence for the philosophy of the MIT bag model; and demonstration that the color gap is substantial - several tens of MeV - even at modest densities. Since the superconductivity is in a pseudoscalar channel, parity is spontaneously broken.

  11. SUPERCONDUCTING PHOTOCATHODES.

    Energy Technology Data Exchange (ETDEWEB)

    SMEDLEY, J.; RAO, T.; WARREN, J.; SEKUTOWICZ, LANGNER, J.; STRZYZEWSKI, P.; LEFFERS, R.; LIPSKI, A.

    2005-10-09

    We present the results of our investigation of lead and niobium as suitable photocathode materials for superconducting RF injectors. Quantum efficiencies (QE) have been measured for a range of incident photon energies and a variety of cathode preparation methods, including various lead plating techniques on a niobium substrate. The effects of operating at ambient and cryogenic temperatures and different vacuum levels on the cathode QE have also been studied.

  12. The Linac Coherent Light Source Project

    Energy Technology Data Exchange (ETDEWEB)

    Galayda, John N

    2003-08-11

    The Linac Coherent Light Source Project will make use of the last kilometer of the SLAC Linac to create the world's first ''hard'' x-ray laser. A high-brightness photocathode gun and 150 MeV pre-accelerator will be installed in an alcove adjoining the main linac tunnel. It will provide 1 nanocoulomb electron bunches at 120 Hz. The main linac will be modified to incorporate two chicane bunch compressors. Electron bunches with 230 fsec FWHM duration and 3400 ampere peak current will be delivered to the enclosure presently housing the Final Focus Test Beam Facility. These electron bunches will pass through a 122-meter undulator channel, producing a burst of coherent x-rays with peak brightness ten orders of magnitude higher than is presently available from the brightest third-generation storage ring sources. This extraordinary brightness and coherence is the result of the ''self-amplified spontaneous emission'' (SASE) process. The LCLS Project will include x-ray optics, diagnostics and beamline facilities in two experiment halls, respectively located 40 meters and 322 meters from the source of x-rays. The LCLS will be constructed by a collaboration of US laboratories: Argonne National Labs, Lawrence Livermore National Lab, and SLAC. A conceptual design has been completed and funds for a more complete design are expected in October 2002. The Project completion date is September 2008.

  13. Cyclotron and linac production of Ac-225.

    Science.gov (United States)

    Melville, Graeme; Allen, Barry J

    2009-04-01

    Radium needles that were once implanted into tumours as a cancer treatment are now obsolete and constitute a radioactive waste problem, as their half-life is 1600 years. The reduction of radium by photonuclear transmutation by bombarding Ra-226 with high-energy photons from a medical linear accelerator (linac) has been investigated. A linac dose of 2800 Gy produced about 2.4 MBq (64 microCi) of Ra-225, which decays to Ac-225 and can then be used for 'Targeted Alpha Therapy' (TAT) of cancer. This result, while consistent with theoretical calculations, is far too low to be of practical use unless much larger quantities of radium are irradiated. The increasing application of Ac-225 for cancer therapy indicates the potential need for its increased production and availability. This paper investigates the possibility of producing of Ac-225 in commercial quantities, which could potentially reduce obsolete radioactive material and displace the need for expensive importation of Ac-225 from the USA and Russia in the years ahead. Scaled up production of Ac-225 could theoretically be achieved by the use of a high current cyclotron or linac. Production specifications are determined for a linac in terms of current, pulse length and frequency, as well as an examination of other factors such as radiation issues and radionuclei separation. Yields are compared with those calculated for the Australian National Cyclotron in Sydney.

  14. First beam in Linac4 DTL

    CERN Multimedia

    Katarina Anthony

    2014-01-01

    Following the installation of the Linac4 Drift Tube Linac (DTL) earlier this summer (see here), the first DTL tank saw beams at 12 MeV on 5 August.   Transverse emittance measured at 12 MeV after the DTL tank1 using a temporary slit-and-grid emittance device. You never forget your first beam. That was especially true for the Linac4 DTL team, as it followed years of design, construction and vigorous testing. "We performed countless measurements of the geometry, vacuum and magnet polarisation of the DTL tanks while we were in the workshop," says Suitbert Ramberger, project engineer for the Linac4 DTL. "Add that preparation to the excellent RF conditioning that we carried out in the weeks before the beam tests and I was confident that the acceleration with beam would fully meet expectations!" Indeed it did. Beam commissioning tests ran until 21 August and found the DTL operating with nominal transmission. This successful run has confirmed the innovative design ...

  15. Preinjector for Linac 1, SAMES generator

    CERN Multimedia

    1974-01-01

    For a description of the Linac 1 preinjector, please see first 7403070x. When the original 520 kV Cockcroft-Walton generator broke down in 1973, it was replaced by this much smaller 520 kV SAMES generator, seen here sitting on the floor of the Faraday cage.

  16. The Comparative Research on SRHMS and SCL-90 Applied in College Students’ Mental Health Measurement%SRHMS与SCL-90用于大学生心理健康测评的比较

    Institute of Scientific and Technical Information of China (English)

    张羽; 吴靖芳

    2013-01-01

      Objective To explore whether the result of SRHMS applied in college students’mental health measurement is consistent with that of SCL-90. Methods 321 sophomores specialized in education, medicine and finance in a certain college of Zhangjiakou were measured simultaneously by SRHMS and SCL-90, and the results were made statistical analysis. Results (1) The results of SRHMS and SCL-90 were consistent, which indicated that the mental status of students in education was the worst, then those in finance, and those in medicine were the best (P<0.01). (2) High-score students in SCL-90 made a poorer score in SRHMS than low-score students in SCL-90, and the difference was remarkable by T-tested. (3) Pearson analysis of scores in each SCL-90 factor and each SRHMS item showed that:score in each SCL-90 factor and that in each SRHMS item had negative correlation (P<0.01). Total score in SCL-90 also had negative correlation with item of physiology, psychology and social health in SRHMS (P<0.01). Conclusion SRHMS and SCL-90 have certain consistency and can be confirmed by each other in a certain range.%  目的为了考查两种不同量表SRHMS和SCL-90在评定大学生心理健康的结果上是否具有一致性。方法选取张家口市某专科学校师范类、医学类、财经类二年级学生共321人,用两种量表同时进行心理健康评定,对结果进行统计分析。结果(1)用两个量表对心理健康状况的评定结果具有一致性,师范类学生最差,其次是财经类学生,医学类学生最好(P<0.01);(2)SCL-90高分组的学生在SRHMS量表上得分低于SCL-90低分组的得分,经t检验,差异有统计学意义(P<0.05);(3)将SCL-90各因子与SRHMS各分项目得分进行Pearson相关分析显示:SCL-90各因子与SRHMS各分项目得分均有显著负相关(P<0.01);SCL-90总分与SRHMS中的生理、心理、社会健康子量表亦有显著相关(P<0.01)。结论两个量表

  17. Statistical simulations of machine errors for LINAC4

    CERN Document Server

    Baylac, M; Froidefond, E; Sargsyan, E

    2006-01-01

    LINAC 4 is a normal conducting H- linac proposed at CERN to provide a higher proton flux to the CERN accelerator chain. It should replace the existing LINAC 2 as injector to the Proton Synchrotron Booster and can also operate in the future as the front end of the SPL, a 3.5 GeV Superconductingg Proton Linac. LINAC 4 consists of a Radio-Frequency Quadrupole, a chopper line, a Drift Tube Linac (DTL) and a Cell Coupled DTL all operating at 352 MHz and finally a Side Coupled Linac at 704 MHz. Beam dynamics was studied and optimized performing end-to-end simulations. This paper presents statistical simulations of machine errors which were performed in order to validate the proposed design.

  18. Conservation and Diversification of the SHR-SCR-SCL23 Regulatory Network in the Development of the Functional Endodermis in Arabidopsis Shoots.

    Science.gov (United States)

    Yoon, Eun Kyung; Dhar, Souvik; Lee, Mi-Hyun; Song, Jae Hyo; Lee, Shin Ae; Kim, Gyuree; Jang, Sejeong; Choi, Ji Won; Choe, Jeong-Eun; Kim, Jeong Hoe; Lee, Myeong Min; Lim, Jun

    2016-08-01

    Development of the functional endodermis of Arabidopsis thaliana roots is controlled, in part, by GRAS transcription factors, namely SHORT-ROOT (SHR), SCARECROW (SCR), and SCARECROW-LIKE 23 (SCL23). Recently, it has been shown that the SHR-SCR-SCL23 regulatory module is also essential for specification of the endodermis (known as the bundle sheath) in leaves. Nevertheless, compared with what is known about the role of the SHR-SCR-SCL23 regulatory network in roots, the molecular interactions of SHR, SCR, and SCL23 are much less understood in shoots. Here, we show that SHR forms protein complexes with SCL23 to regulate transcription of SCL23 in shoots, similar to the regulation mode of SCR expression. Our results indicate that SHR acts as master regulator to directly activate the expression of SCR and SCL23. In the SHR-SCR-SCL23 network, we found a previously uncharacterized negative feedback loop whereby SCL23 modulates SHR levels. Through molecular, genetic, physiological, and morphological analyses, we also reveal that the SHR-SCR-SCL23 module plays a key role in the formation of the endodermis (known as the starch sheath) in hypocotyls. Taken together, our results provide new insights into the regulatory role of the SHR-SCR-SCL23 network in the endodermis development in both roots and shoots.

  19. Programación de Controladores Lógicos (PLC) mediante Ladder y Lenguaje de Control Estructurado (SCL) en MATLAB/Programming logic controllers (PLC) using ladder and structured control language (SCL) in MATLAB/Programação de Controladores Lógicos (PLC) mediante Ladder e Linguagem de Controle Estruturado (SCL) em MATLAB

    National Research Council Canada - National Science Library

    Heyder David Páez-Logreira; Ronald Zamora-Musa; José Bohórquez-Pérez

    2015-01-01

    .... In this article, the results LADDER programming language and language are compared with SCL generated by Simulink PLC Coder MATLAB tool taking as a case study the calculating the volume of a tank...

  20. Obstetrics patients SCL-90 scale measurement and evaluation of psychological intervention%妇产科患者SCL-90量表测量及心理干预评价

    Institute of Scientific and Technical Information of China (English)

    刘东华

    2015-01-01

    目的:探讨妇产科患者精神心理状况SCL-90量表测量及心理干预评价。方法患者入院后进行SCL-90量表测量,评价患者精神心理状况并针对患者进行个体化心理干预,干预后再次进行SCL-90量表测量。结果心理干预后SCL-90因子中躯体化、人际关系敏感、抑郁、焦虑、恐怖、偏执与心理干预前比较差异有统计学意义(P<0.05),而强迫、敌对因子与心理干预前比较差异无统计学意义(P>0.05)。心理干预后SCL-90总评分与心理干预前相比差异具有统计学意义(P<0.05)。结论心理干预有利于改善患者精神心理不良情绪。%Objective To investigate the psychological status of patients in the Department of gynecology and obstetrics SCL-90 scale measurement and evaluation of psychological intervention. Methods The hospitalization patients were admitted to SCL-90 scale,evaluation patients’mental state and according to individual condition to give the psychological intervention ,again SCL-90 scale after the intervention psychological. Results Psychological intervention after the SCL-90 factors of somatization, interpersonal sensitivity, depression, anxiety, terror, paranoia and before mental intervention, the difference was statistically significant (P 0.05). SCL-90 total score after psychological intervention compared with psychological intervention before the differences was statistically significant (P < 0.05). Conclusion The psychological intervention is helpful to improve the patients’mental psychological feelings.

  1. Prompt radiation, shielding and induced radioactivity in a high-power 160 MeV proton linac

    Science.gov (United States)

    Magistris, Matteo; Silari, Marco

    2006-06-01

    CERN is designing a 160 MeV proton linear accelerator, both for a future intensity upgrade of the LHC and as a possible first stage of a 2.2 GeV superconducting proton linac. A first estimate of the required shielding was obtained by means of a simple analytical model. The source terms and the attenuation lengths used in the present study were calculated with the Monte Carlo cascade code FLUKA. Detailed FLUKA simulations were performed to investigate the contribution of neutron skyshine and backscattering to the expected dose rate in the areas around the linac tunnel. An estimate of the induced radioactivity in the magnets, vacuum chamber, the cooling system and the concrete shield was performed. A preliminary thermal study of the beam dump is also discussed.

  2. Design and evaluation of a low-level RF control system analog/digital receiver for the ILC main Linacs

    Energy Technology Data Exchange (ETDEWEB)

    Mavric, Uros; Vidmar, Matjaz; Chase, Brian; /Fermilab

    2008-06-01

    The proposed RF distribution scheme for the two 15 km long ILC LINACs, uses one klystron to feed 26 superconducting RF cavities operating at 1.3 GHz. For a precise control of the vector sum of the signals coming from the SC cavities, the control system needs a high performance, low cost, reliable and modular multichannel receiver. At Fermilab we developed a 96 channel, 1.3 GHz analog/digital receiver for the ILC LINAC LLRF control system. In the paper we present a balanced design approach to the specifications of each receiver section, the design choices made to fulfill the goals and a description of the prototyped system. The design is tested by measuring standard performance parameters, such as noise figure, linearity and temperature sensitivity. Measurements show that the design meets the specifications and it is comparable to other similar systems developed at other laboratories, in terms of performance.

  3. Design and evaluation of a low-level RF control system analog/digital receiver for the ILC main LINACs

    Energy Technology Data Exchange (ETDEWEB)

    Mavric, Uros [Fermilab, P.O. Box 500, 60510 Batavia, IL (United States)], E-mail: mavric@fnal.gov; Chase, Brian [Fermilab, P.O. Box 500, 60510 Batavia, IL (United States); Vidmar, Matjaz [Faculty of Electrical Engineering in Ljubljana, Trzaska 25, 1000 Ljubljana (Slovenia)

    2008-08-21

    The proposed RF distribution scheme for the two 15 km long ILC LINACs uses one klystron to feed 26 superconducting RF cavities operating at 1.3 GHz. For a precise control of the vector sum of the signals coming from the SC cavities, the control system needs a high-performance, low-cost, reliable and modular multichannel receiver. At Fermilab we developed a 96-channel, 1.3 GHz analog/digital receiver for the ILC LINAC LLRF control system. In this paper we present a balanced design approach to the specifications of each receiver section, the design choices made to fulfill the goals and a description of the prototyped system. The design is tested by measuring standard performance parameters, such as noise figure, linearity and temperature sensitivity. Measurements show that the design meets the specifications and it is comparable to other similar systems developed at other laboratories, in terms of performance.

  4. Split ring resonator for the Argonne superconducting heavy ion booster

    Energy Technology Data Exchange (ETDEWEB)

    Shepard, K.W.; Scheibelhut, C.H.; Benaroya, R.; Bollinger, L.M.

    1977-01-01

    A split-ring resonator for use in the ANL superconducting heavy-ion linac was constructed and is being tested. The electromagnetic characteristics of the 98-MHz device are the same as the unit described earlier, but the housing is formed of a new material consisting of niobium sheet explosively bonded to copper. The niobium provides the superconducting path and the copper conducts heat to a small area cooled by liquid helium. This arrangement greatly simplified the cryogenic system. Fabrication of the housing was relatively simple, with the result that costs have been reduced substantially. The mechanical stability of the resonator and the performance of the demountable superconducting joints are significantly better than for the earlier unit.

  5. First demonstration and performance of an injection locked continuous wave magnetron to phase control a superconducting cavity

    Energy Technology Data Exchange (ETDEWEB)

    A.C. Dexter, G. Burt, R.G. Carter, I. Tahir, H. Wang, K. Davis, R. Rimmer

    2011-03-01

    The applications of magnetrons to high power proton and cw electron linacs are discussed. An experiment is described where a 2.45 GHz magnetron has been used to drive a single cell superconducting cavity. With the magnetron injection locked, a modest phase control accuracy of 0.95° rms has been demonstrated. Factors limiting performance have been identified.

  6. SCL-90-R Symptom Profiles and Outcome of Short-Term Psychodynamic Group Therapy

    DEFF Research Database (Denmark)

    Jensen, Hans Henrik; Mortensen, Erik Lykke; Lotz, Martin

    2013-01-01

    to phobic anxiety and anxiety patients, patients with interpersonal sensitivity obtained overall the most optimal outcome. The phobic anxiety scale, social network support, and years of school education were independent predictors of GSI remission, and a low anxiety score and absence of phobic anxiety...... target symptoms were independent predictors of remission of target symptom pathology. Conclusions. The negative results as associated with the SCL-90-R phobic anxiety scale and the phobic anxiety target symptom group are largely in agreement with recent studies. In contrast, whatever the diagnoses...

  7. Six-Correction Logic (SCL Gates in Quantum-dot Cellular Automata (QCA

    Directory of Open Access Journals (Sweden)

    Md. Anisur Rahman

    2015-11-01

    Full Text Available Quantum Dot Cellular Automata (QCA is a promising nanotechnology in Quantum electronics for its ultra low power consumption, faster speed and small size features. It has significant advantages over the Complementary Metal–Oxide–Semiconductor (CMOS technology. This paper present, a novel QCA representation of Six-Correction Logic (SCL gate based on QCA logic gates: the Maj3, Maj AND gate and Maj OR. In order to design and verify the functionality of the proposed layout, QCADesigner a familiar QCA simulator has been employed. The simulation results confirm correctness of the claims and its usefulness in designing a digital circuits.

  8. Induction linacs for heavy ion fusion research

    Energy Technology Data Exchange (ETDEWEB)

    Fessenden, T.J.

    1984-05-01

    The new features of employing an induction linac as a driver for inertial fusion involve (1) transport of high-current low-emittance heavy ion beams, (2) multiple independently-focussed beams threading the same accelerator structure, and (3) synthesis of voltage waveforms to accomplish beam current amplification. A research program is underway at LBL to develop accelerators that test all these features with the final goal of producing an ion beam capable of heating matter to approx. 70 eV. This paper presents a discussion of some properties of induction linacs and how they may be used for HIF research. Physics designs of the High Temperature Experiment (HTE) and the Multiple Beam Experiment (MBE) accelerators are presented along with initial concepts of the MBE induction units.

  9. Electronics Platform of PS Linac 1 Preinjector

    CERN Multimedia

    1974-01-01

    For servicing during shutdowns, a draw-bridge from a door in the Faraday cage led to the "electronics platform" of the linac 1 preinjector (at 520 kV when in operation) and the top of the electronics platform was lifted on hydraulic jacks for easy access. Henry Charmot is busy with a service. The platform contained the electronics for the ion source, controlled from outside the Faraday cage via an infrared optical link. The ion source, also at 520 kV potential, is housed in the drum, visible in the background, on the insulator column, which at its right end is mounted at ground potential. Behind the wall, to the right, is the 50 MeV linac 1. See also 7403064X, 7403066X, 7403124.

  10. Accelerator Control System at KEKB and Linac

    CERN Document Server

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

    2012-01-01

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

  11. Re-circulating linac vacuum system

    Energy Technology Data Exchange (ETDEWEB)

    Wells, Russell P.; Corlett, John N.; Zholents, Alexander A.

    2003-05-09

    The vacuum system for a proposed 2.5 GeV, 10{Mu}A recirculating linac synchrotron light source [1] is readily achievable with conventional vacuum hardware and established fabrication processes. Some of the difficult technical challenges associated with synchrotron light source storage rings are sidestepped by the relatively low beam current and short beam lifetime requirements of a re-circulating linac. This minimal lifetime requirement leads directly to relatively high limits on the background gas pressure through much of the facility. The 10{Mu}A average beam current produces very little synchrotron radiation induced gas desorption and thus the need for an ante-chamber in the vacuum chamber is eliminated. In the arc bend magnets, and the insertion devices, the vacuum chamber dimensions can be selected to balance the coherent synchrotron radiation and resistive wall wakefield effects, while maintaining the modest limits on the gas pressure and minimal outgassing.

  12. RESONANCE CONTROL FOR THE COUPLED CAVITY LINAC AND DRIFT TUBE LINAC STRUCTURES OF THE SPALLATION NEUTRON SOURCE LINAC USING A CLOSED-LOOP WATER COOLING SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Bernardin, J. D. (John D.); Brown, R. L. (Richard L.); Brown, S. K. (Stanley K.); Bustos, G. R. (Gerald R.); Crow, M.L. (Martin L.); Gregory, W. S.; Hood, M. E. (Michael E.); Jurney, J. D. (James D.); Medalen, I. (Ivan); Owen, A. C. (Albert C.); Weiss, Robert E.

    2001-01-01

    The Spallation Neutron Source (SNS) is a facility being designed for scientific and industrial research and development. SNS will generate and use neutrons as a diagnostic tool for medical purposes, material science, etc. The neutrons will be produced by bombarding a heavy metal target with a high-energy beam of protons, generated and accelerated with a linear particle accelerator, or linac. The low energy end of the linac consists of two room temperature copper structures, the drift tube linac (DTL), and the coupled cavity linac (CCL). Both of these accelerating structures use large amounts of electrical energy to accelerate the protons to an energy of 185 MeV. Approximately 60-80% of the electrical energy is dissipated in the copper structure and must be removed. This is done using specifically designed water cooling passages within the linac's copper structure. Cooling water is supplied to these cooling passages by specially designed resonance control and water cooling systems.

  13. LINAC4 takes a tour of Europe

    CERN Multimedia

    Katarina Anthony

    2011-01-01

    Along the German Autobahnen, a truck carrying 20 tonnes of copper is on its way to Poland. The metal has already made a short tour of Europe, yet the drive across the high-speed highway is only the beginning of its transformation into CERN’s next linear accelerator, LINAC4.   Grzegorz Wrochna (left), director of the Andrzej Soltan Institute for Nuclear Studies (IPJ), and Rolf Heuer (right), CERN DG, sign the framework agreement between the two institutes. By the summer of 2012, the PI-Mode Structures (PIMS) will be constructed and completely installed in the LINAC4 tunnel. The PIMS cavities are the final accelerating structures needed for LINAC4, and have been designed to accelerate protons from 100 to 160MeV. While the first cavity was built entirely at CERN, construction of the remaining cavities has become a larger, multi-national operation. In a 1 million euro framework agreement signed on 11 February by the Director-General, the Andrzej Soltan Institute for Nuclear Studies in Swie...

  14. Status of Linac4 construction at CERN

    CERN Document Server

    Vretenar, M

    2010-01-01

    Linac4 is a 160 MeV normal-conducting H¯ linear accelerator which is being built at CERN in the frame of a program for increasing the luminosity of the LHC. The project started in 2008 and delivery of beam to the CERN accelerator chain is foreseen from early 2015. The new linac will be housed in an underground tunnel close to the present Linac2; a surface building will house RF and other infrastructure. The civil engineering work started in October 2008 will be soon completed. Installation of the infrastructure will take place in 2011, and from 2012 will be installed the main machine elements. The ion source is presently operational on a test stand, where it will be followed in 2011 by a 3 MeV RFQ under construction in the CERN workshops. Prototypes of the three different types of accelerating structures have been tested; construction of the 22 accelerating cavities has started, supported by a network of agreements with external laboratories and institutions. Commissioning will take place in stages, starting...

  15. Prototype of linac BLM at NSRL

    Science.gov (United States)

    Zeng, Ming; Li, Yuxiong; Gong, Guanghua; Li, Juexin; Shao, Beibei; Zhao, Zhengguo

    2007-08-01

    A prototype of the Beam Loss Monitoring (BLM) System for the linac and transportation line has been built up in National Synchrotron Radiation Laboratory. Different from the storage ring, the radiation field around linac and transportation line have a duty factor of 10 -6 and a dose rate of hundreds Gy/h. The Monte-Carlo calculation gave the dose, flux, energy and direction distributions of the radiation field. According to the simulation result, the proper type of detector was chosen and the installation positions were selected accordingly. The widely used ionization chamber is not suitable to give accurate and real-time information of beam loss due to its large dimension and slow respond speed. Several PIN silicon diode-based detectors were designed and tested, and a charge-balanced integrating amplifier circuit was applied to read out the charge. A distributed data acquisition system based on embedded Ethernet technology was implemented in the prototype, which can offer a web server from the microcontroller. From preliminary tests, this new prototype was proved to be sensitive to the change of the linac status, and is a useful tool for monitoring and adjusting machine parameters. Further analyses are required to achieve a more accurate measurement of the beam loss.

  16. Wake fields in SLAC Linac Collimators

    Energy Technology Data Exchange (ETDEWEB)

    Novokhatski, Alexander [SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States); Decker, F. -J. [SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States); Smith, H. [SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States); Sullivan, M. [SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States)

    2014-12-02

    When a beam travels near collimator jaws, it gets an energy loss and a transverse kick due to the backreaction of the beam field diffracted from the jaws. The effect becomes very important for an intense short bunch when a tight collimation of the background beam halo is required. In the Linac Coherent Light Source at SLAC a collimation system is used to protect the undulators from radiation due to particles in the beam halo. The halo is most likely formed from gun dark current or dark current in some of the accelerating sections. However, collimators are also responsible for the generation of wake fields. The wake field effect from the collimators not only brings an additional energy jitter and change in the trajectory of the beam, but it also rotates the beam on the phase plane, which consequently leads to a degradation of the performance of the Free Electron Laser at the Linac Coherent Light Source. In this paper, we describe a model of the wake field radiation in the SLAC linac collimators. We use the results of a numerical simulation to illustrate the model. Based on the model, we derive simple formulas for the bunch energy loss and the average kick. In addition, we also present results from experimental measurements that confirm our model.

  17. Preinjector for Linac 1, Faraday cage

    CERN Multimedia

    1974-01-01

    The 50 MeV Linac 1 started up in 1958 as injector to the 26 GeV PS, with a 520 kV Cockcroft-Walton generator as its preinjector, housed in a vast Faraday cage, visible here. When the Cockcroft-Walton broke down in 1973, it was replaced by a much smaller SAMES generator, of the kind used for electrostatic separators. From 1980 on, Linac 2 took over as injector for the 800 MeV Booster, and Linac 1 continued as injector for LEAR. In 1984, the electrostatic preinjector (i.e. the Faraday cage with its contents, SAMES generator and all) was replaced by a 520 keV RFQ. At the lower left corner we see the HV connectors to the SAMES generator, at the right edge part of the opened electronics-platform. Jean-Luc Vallet sees to it that all parts are properly grounded. See also 7403073X, 7403074X, 7403081X, 7403083X.

  18. Emission line tomography of the short period cataclysmic variables CC Scl and V2051 Oph

    CERN Document Server

    Longa-Peña, P; Marsh, T

    2014-01-01

    We present time-series spectroscopy of two short period cataclysmic variables, CC Scl and V2051 Oph, to test the efficiency of Doppler tomography-based methods in constraining orbital parameters of evolved cataclysmic variables. We find that the Ca~II triplet lines offer superior diagnostics, revealing emission components from the mass donors and sharp images of the accretion discs. Furthermore, we use Monte-Carlo methods to estimate the uncertainties from ensembles of Doppler maps. We compare our new methods against traditional radial velocity methods and show that they offer a valid route towards system parameter determination. Our analysis of CC Scl suggests a low mass ratio of $q=0.08\\pm0.03$ with a primary velocity of $K_1=37\\pm14$ km/s. This mass ratio is in between the pre- and post-period minimum status, however our $K_1$ solution favours a post-period minimum system. Our derived parameters for V2051 Oph ($q= 0.16\\pm 0.03$, $K_1=97\\pm10$ km/s) are in agreement with the eclipse solution ($q=0.19\\pm0.03...

  19. Itinerant Ferromagnetism and Superconductivity

    OpenAIRE

    Karchev, Naoum

    2004-01-01

    Superconductivity has again become a challenge following the discovery of unconventional superconductivity. Resistance-free currents have been observed in heavy-fermion materials, organic conductors and copper oxides. The discovery of superconductivity in a single crystal of $UGe_2$, $ZrZn_2$ and $URhGe$ revived the interest in the coexistence of superconductivity and ferromagnetism. The experiments indicate that: i)The superconductivity is confined to the ferromagnetic phase. ii)The ferromag...

  20. 100 years of superconductivity

    CERN Document Server

    Rogalla, Horst

    2011-01-01

    Even a hundred years after its discovery, superconductivity continues to bring us new surprises, from superconducting magnets used in MRI to quantum detectors in electronics. 100 Years of Superconductivity presents a comprehensive collection of topics on nearly all the subdisciplines of superconductivity. Tracing the historical developments in superconductivity, the book includes contributions from many pioneers who are responsible for important steps forward in the field.The text first discusses interesting stories of the discovery and gradual progress of theory and experimentation. Emphasizi

  1. Design, construction and tests of a 3 GHz proton linac booster (LIBO) for cancer therapy

    Science.gov (United States)

    Berra, Paolo

    2007-12-01

    In the last ten years the use of proton beams in radiation therapy has become a clinical tool for treatment of deep-seated tumours. LIBO is a RF compact and low cost proton linear accelerator (SCL type) for hadrontherapy. It is conceived by TERA Foundation as a 3 GHz Linac Booster, to be mounted downstream of an existing cyclotron in order to boost the energy of the proton beam up to 200 MeV, needed for deep treatment (~25 cm) in the human body. With this solution it is possible to transform a low energy commercial cyclotron, normally used for eye melanoma therapy, isotope production and nuclear physics research, into an accelerator for deep-seated tumours. A prototype module of LIBO has been built and successfully tested with full RF power at CERN and with proton beam at INFN Laboratori Nazionali del Sud (LNS) in Catania, within an international collaboration between TERA Foundation, CERN, the Universities and INFN groups of Milan and Naples. The mid-term aim of the project is the technology transfer of the accumulated know-how to a consortium of companies and to bring this novel medical tool to hospitals. The design, construction and tests of the LIBO prototype are described in detail.

  2. Design Construction and Test Results of a HTS Solenoid For Energy Recovery Linac

    Energy Technology Data Exchange (ETDEWEB)

    Anerella, M; Ben-Zvi, I; Kayran, D; McIntyre, G; Muratore, J; Plate, S; Sampson, W; Cole, M

    2011-03-28

    An innovative feature of the proposed Energy Recovery Linac (ERL) is the use of a solenoid made with High Temperature Superconductor (HTS) with the Superconducting RF cavity. The use of HTS allows solenoid to be placed in close proximity to the cavity and thus provides early focusing of the electron beam. In addition, cryogenic testing at {approx}77 K is simpler and cheaper than 4 K testing. This paper will present the design, construction and test results of this HTS solenoid. The HTS solenoid in the proposed ERL will be situated in the transition region between the superconducting cavity at {approx}4 K and the cryostat at the room temperature. Solenoid inside the cryogenic structure provides an early focusing and hence low emittance beam. The temperature in the transition region will be too high for a conventional low temperature superconductor and resistive heat load from copper coils will be too high on cryogenic system. HTS coils also allow much higher current density and significant reduction in size as compared to copper coils. Hence HTS solenoid provide a unique and technically superior solution. The use of a HTS solenoid with superconducting cavity offers a unique option as it can be placed in a cold to warm transition region to provide early focussing without using additional space. Construction and test results so far are very encouraging for its use in the ERL project.

  3. S-band linac-based X-ray source with {pi}/2-mode electron linac

    Energy Technology Data Exchange (ETDEWEB)

    Deshpande, Abhay, E-mail: abhay@post.kek.jp [Department of Accelerator Science, School of High Energy Accelerator Science, Graduate University for Advanced Studies, Shonan International Village, Hayama, Miura, Kanagawa 240-0193 (Japan); Society for Applied Microwave Electronic Engineering and Research (SAMEER), R and D Laboratory of the Government of India, IIT Campus, Powai, Mumbai 400 076 (India); Araki, Sakae [High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Dixit, Tanuja [Society for Applied Microwave Electronic Engineering and Research (SAMEER), R and D Laboratory of the Government of India, IIT Campus, Powai, Mumbai 400 076 (India); Fukuda, Masafumi [High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Krishnan, R; Pethe, Sanjay [Society for Applied Microwave Electronic Engineering and Research (SAMEER), R and D Laboratory of the Government of India, IIT Campus, Powai, Mumbai 400 076 (India); Sakaue, Kazuyuki [Waseda University, Shinjuku-ku, Tokyo 169-8555 (Japan); Terunuma, Nobuhiro; Urakawa, Junji [High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Washio, Masakazu [Waseda University, Shinjuku-ku, Tokyo 169-8555 (Japan)

    2011-05-01

    The activities with the compact X-ray source are attracting more attention, particularly for the applications of the source in medical fields. We propose the fabrication of a compact X-ray source using the SAMEER electron linear accelerator and the KEK laser undulator X-ray source (LUCX) technologies. The linac developed at SAMEER is a standing wave side-coupled S-band linac operating in the {pi}/2 mode. In the proposed system, a photocathode RF gun will inject bunches of electrons in the linac to accelerate and achieve a high-energy, low-emittance beam. This beam will then interact with the laser in the laser cavity to produce X-rays of a type well suited for various applications. The side-coupled structure will make the system more compact, and the {pi}/2 mode of operation will enable a high repetition rate operation, which will help to increase the X-ray yield.

  4. Emittance coupling driven by space charge in the CSNS linac

    Institute of Scientific and Technical Information of China (English)

    YIN Xue-Jun; FU Shi-Nian; PENG Jun

    2009-01-01

    In the conventional design of RF linacs, the bunched beams are not in thermal equilibrium. The space charge forces couple the particle motions between the transverse and the longitudinal directions. Fur-thermore it will cause the equipartitioning process which leads to emittance growth and halo formation. In the design of the China Spallation Neutron Source (CSNS) linac, three cases are investigated using the Hofmann stability charts. In this paper, we present the equipartitioning beam study of the CSNS Alvarez DTL linac.

  5. Fiducialization of Superconducting Radio Frequency Cryomodules at Jefferson Lab

    Energy Technology Data Exchange (ETDEWEB)

    C. J. Curtis; J. Dahlberg; W. Oren; J. Preble; K. Tremblay

    2006-09-26

    During the early 1990's the Continuous Electron Beam Accelerator Facility (CEBAF), was under construction in Newport News, Virginia. The facility was to be the first of its kind in that it was to provide a continuous beam of electrons for experimental physics at energies of several GeV. One of the key elements of this unique machine was the 338 superconducting radio frequency (SRF) cavities built into 42 cryomodules and arranged in two linacs. These were linked by arcs of conventional magnets which allowed recirculation through the linacs up to five times, in order to achieve the design energy of 4GeV. Within each cryomodule the cavities were aligned and referenced to external fiducials allowing alignment on the design beampath. This paper describes the process developed to achieve this, how it evolved with improving instrumentation, and the results obtained. Suggestions for alternative methods which may prove useful for future projects are also discussed.

  6. Linac4: the final assembly stage is under way

    CERN Multimedia

    CERN Bulletin

    2013-01-01

    The Linac4 radiofrequency quadrupole (RFQ) module was installed at the accelerator test-stand in Building 152 last August. After an assembly phase and tests that concluded last March with the acceleration of a hydrogen beam to 3 MeV, the module has just been permanently installed in the new Linac4 tunnel (Building 400). The installation of the MEBT (Medium Energy Beam Transport) will begin shortly, followed by the start of the first Linac4 commissioning phase.     To find out more about the Linac4 RFQ module, read the previous Bulletin articles published in Nos. 21-22/2010 and 35-36/2012.

  7. Evaluation of photoneutron production at high energy LINACS

    Energy Technology Data Exchange (ETDEWEB)

    Bell, Z.W.

    1995-04-24

    This report describes an estimate of neutron production at a 9 MeV LINAC, and the potential for photoactivation of materials present at the LINAC facility. It was found that only isotopes of U, W, Ta, and Pb had daughters whose activities might be measurable. The LINAC was found to be capable of producing in the neighborhood of 10{sup 10} neutrons/second from these heavy metals, and that subsequent neutron activation might be more of a concern. Monte Carlo simulation of neutron transport and capture in the concrete and steel found in the LINAC vault indicates that {sup 55}Fe may be produced in measurable quantities.

  8. Oxygen ion source and RFQ for Linac 1

    CERN Multimedia

    Photographic Service

    1986-01-01

    As injector to the PS Booster, Linac 1 was replaced by Linac 2 in 1980. It continued to be used for the acceleration of oxygen and sulfur ions. In 1984, its Cockcroft-Walton preinjector was replaced by an RFQ. In the foreground at the right is the oxygen ion source. A 90 deg bending magnet selects O6+ ions which are preaccelerated in an RFQ and enter Linac 1, at the far left. In the background is the proton and negative hydrogen ion source, followed by the 520 keV RFQ-1 and a bending magnet towards the entrance of Linac 1.

  9. A monitor unit "odometer" for measuring linac workload.

    Science.gov (United States)

    Evans, M D; Larkin, J J; Léger, P; Podgorsak, E B

    2001-12-01

    The annual linac workload is often required by regulatory agencies to assess compliance with license conditions. Summation of the monitor units produced by the machine is generally used for this purpose. Various methods of estimating this value have inherent inaccuracies. We have built an integrating Monitor Unit "odometer" that is able to automatically accumulate all MUs delivered by the linac and segregate the total by mode (photon or electron) and energy. The device has been used to record clinical linac MU workloads for 10 months, and was installed in a new dual-energy linac during the acceptance and commissioning process.

  10. Interdigital H -mode drift-tube linac design with alternative phase focusing for muon linac

    Science.gov (United States)

    Otani, M.; Mibe, T.; Yoshida, M.; Hasegawa, K.; Kondo, Y.; Hayashizaki, N.; Iwashita, Y.; Iwata, Y.; Kitamura, R.; Saito, N.

    2016-04-01

    We have developed an interdigital H-mode (IH) drift-tube linac (DTL) design with an alternative phase focusing (APF) scheme for a muon linac, in order to measure the anomalous magnetic moment and electric dipole moment (EDM) of muons at the Japan Proton Accelerator Research Complex (J-PARC). The IH-DTL accelerates muons from β =v /c =0.08 to 0.28 at an operational frequency of 324 MHz. The output beam emittances are calculated as 0.315 π and 0.195 π mm mrad in the horizontal and vertical directions, respectively, which satisfies the experimental requirement.

  11. High field superconducting magnets

    Science.gov (United States)

    Hait, Thomas P. (Inventor); Shirron, Peter J. (Inventor)

    2011-01-01

    A superconducting magnet includes an insulating layer disposed about the surface of a mandrel; a superconducting wire wound in adjacent turns about the mandrel to form the superconducting magnet, wherein the superconducting wire is in thermal communication with the mandrel, and the superconducting magnet has a field-to-current ratio equal to or greater than 1.1 Tesla per Ampere; a thermally conductive potting material configured to fill interstices between the adjacent turns, wherein the thermally conductive potting material and the superconducting wire provide a path for dissipation of heat; and a voltage limiting device disposed across each end of the superconducting wire, wherein the voltage limiting device is configured to prevent a voltage excursion across the superconducting wire during quench of the superconducting magnet.

  12. Analysis and measurement of the transfer matrix of a 9-cell, 1.3-GHz superconducting cavity

    Science.gov (United States)

    Halavanau, A.; Eddy, N.; Edstrom, D.; Harms, E.; Lunin, A.; Piot, P.; Romanov, A.; Ruan, J.; Solyak, N.; Shiltsev, V.

    2017-04-01

    Superconducting linacs are capable of producing intense, stable, high-quality electron beams that have found widespread applications in science and industry. The 9-cell, 1.3-GHz superconducting standing-wave accelerating rf cavity originally developed for e+/e- linear-collider applications [B. Aunes, et al. Phys. Rev. ST Accel. Beams 3, 092001 (2000), 10.1103/PhysRevSTAB.3.092001] has been broadly employed in various superconducting-linac designs. In this paper we discuss the transfer matrix of such a cavity and present its measurement performed at the Fermilab Accelerator Science and Technology (FAST) facility. The experimental results are found to be in agreement with analytical calculations and numerical simulations.

  13. First operation of the rf-focused interdigital linac structure

    Science.gov (United States)

    Joel Starling, W.; Swenson, Donald A.

    2007-08-01

    The new rf-focused interdigital (RFI) linac structure came into operation at the Linac Systems laboratory in May of 2006, after a multi-year development program supported by the US Department of Energy. The RFI linac structure is basically an interdigital (or Wideröe) linac structure with rf quadrupole focusing incorporated into each drift tube. The RFI prototype operates at 200-MHz and consists of an ECR ion source, an Einzel lens LEBT, a radial-strut, four-bar RFQ linac section to 0.75 MeV and an RFI linac section to a final energy of 2.5 MeV. The total length of the prototype is 2.2 m. The RFQ and RFI linac sections are resonantly coupled and require a total of 120 kW of rf power for cavity excitation. The energy of the accelerated beam was confirmed by requiring it to pass through a 2.25-MeV energy-degrading foil. The specifications for the RFI linac prototype were chosen to address the demanding Boron Neutron Capture Therapy medical application. There are, however, many other potential applications for the structure as it has efficiency and size advantages for both protons and heavy ions at a variety of energies and currents. To date, we have achieved a beam current of approximately 1 mA peak at a relatively low duty factor. We continue to improve the performance of the prototype structure on a daily basis as we better understand the optimal operational settings for the prototype system. Now that the first operational milestone for the RFI linac structure has been achieved, Linac Systems will vigorously pursue projects and partnerships for multiple applications such as compact and intense neutron sources, proton and carbon injector linacs for synchrotrons and PET isotope production.

  14. Theory of superconductivity

    CERN Document Server

    Crisan, Mircea

    1989-01-01

    This book discusses the most important aspects of the theory. The phenomenological model is followed by the microscopic theory of superconductivity, in which modern formalism of the many-body theory is used to treat most important problems such as superconducting alloys, coexistence of superconductivity with the magnetic order, and superconductivity in quasi-one-dimensional systems. It concludes with a discussion on models for exotic and high temperature superconductivity. Its main aim is to review, as complete as possible, the theory of superconductivity from classical models and methods up t

  15. Electron bunch structure in energy recovery linac with high-voltage dc photoelectron gun

    Science.gov (United States)

    Saveliev, Y. M.; Jackson, F.; Jones, J. K.; McKenzie, J. W.

    2016-09-01

    The internal structure of electron bunches generated in an injector line with a dc photoelectron gun is investigated. Experiments were conducted on the ALICE (accelerators and lasers in combined experiments) energy recovery linac at Daresbury Laboratory. At a relatively low dc gun voltage of 230 kV, the bunch normally consisted of two beamlets with different electron energies, as well as transverse and longitudinal characteristics. The beamlets are formed at the head and the tail of the bunch. At a higher gun voltage of 325 kV, the beam substructure is much less pronounced and could be observed only at nonoptimal injector settings. Experiments and computer simulations demonstrated that the bunch structure develops during the initial beam acceleration in the superconducting rf booster cavity and can be alleviated either by increasing the gun voltage to the highest possible level or by controlling the beam acceleration from the gun voltage in the first accelerating structure.

  16. IRIDE White Book, An Interdisciplinary Research Infrastructure based on Dual Electron linacs&lasers

    CERN Document Server

    Alesini, D; Anania, M P; Andreas, S; Angelone, M; Arcovito, A; Arnesano, F; Artioli, M; Avaldi, L; Babusci, D; Bacci, A; Balerna, A; Bartalucci, S; Bedogni, R; Bellaveglia, M; Bencivenga, F; Benfatto, M; Biedron, S; Bocci, V; Bolognesi, M; Bolognesi, P; Boni, R; Bonifacio, R; Boscolo, M; Boscherini, F; Bossi, F; Broggi, F; Buonomo, B; Calo', V; Catone, D; Capogni, M; Capone, M; Castellano, M; Castoldi, A; Catani, L; Cavoto, G; Cherubini, N; Chirico, G; Cestelli-Guidi, M; Chiadroni, E; Chiarella, V; Cianchi, A; Cianci, M; Cimino, R; Ciocci, F; Clozza, A; Collini, M; Colo', G; Compagno, A; Contini, G; Coreno, M; Cucini, R; Curceanu, C; Dabagov, S; Dainese, E; Davoli, I; Dattoli, G; De Caro, L; De Felice, P; Della Longa, S; Monache, G Delle; De Spirito, M; Di Cicco, A; Di Donato, C; Di Gioacchino, D; Di Giovenale, D; Di Palma, E; Di Pirro, G; Dodaro, A; Doria, A; Dosselli, U; Drago, A; Escrinabo, R; Esposito, A; Faccini, R; Ferrari, A; Ferrario, M; Filabozzi, A; Filippetto, D; Fiori, F; Frasciello, O; Fulgentini, L; Gallerano, G P; Gallo, A; Gambaccini, M; Gatti, C; Gatti, G; Gauzzi, P; Ghigo, A; Ghiringhelli, G; Giannessi, L; Giardina, G; Giannini, C; Giorgianni, F; Giovenale, E; Gizzi, L; Guaraldo, C; Guazzoni, C; Gunnella, R; Hatada, K; Ivashyn, S; Jegerlehner, F; Keeffe, P O; Kluge, W; Kupsc, A; Iannone, M; Labate, L; Sandri, P Levi; Lombardi, V; Londrillo, P; Loreti, S; Losacco, M; Lupi, S; Macchi, A; Magazu', S; Mandaglio, G; Marcelli, A; Margutti, G; Mariani, C; Mariani, P; Marzo, G; Masciovecchio, C; Masujan, P; Mattioli, M; Mazzitelli, G; Merenkov, N P; Michelato, P; Migliardo, F; Migliorati, M; Milardi, C; Milotti, E; Milton, S; Minicozzi, V; Mobilio, S; Morante, S; Moricciani, D; Mostacci, A; Muccifora, V; Murtas, F; Musumeci, P; Nguyen, F; Orecchini, A; Organtini, G; Ottaviani, P L; Pace, E; Paci, M; Pagani, C; Pagnutti, S; Palmieri, V; Palumbo, L; Panaccione, G C; Papadopoulos, C F; Papi, M; Passera, M; Pasquini, L; Pedio, M; Perrone, A; Petralia, A; Petrillo, C; Petrillo, V; Pillon, M; Pierini, P; Pietropaolo, A; Polosa, A D; Pompili, R; Portoles, J; Prosperi, T; Quaresima, C; Quintieri, L; Rau, J V; Reconditi, M; Ricci, A; Ricci, R; Ricciardi, G; Ripiccini, E; Romeo, S; Ronsivalle, C; Rosato, N; Rosenzweig, J B; Rossi, G; Rossi, A A; Rossi, A R; Rossi, F; Russo, D; Sabatucci, A; Sabia, E; Sacchetti, F; Salducco, S; Sannibale, F; Sarri, G; Scopigno, T; Serafini, L; Sertore, D; Shekhovtsova, O; Spassovsky, I; Spadaro, T; Spataro, B; Spinozzi, F; Stecchi, A; Stellato, F; Surrenti, V; Tenore, A; Torre, A; Trentadue, L; Turchini, S; Vaccarezza, C; Vacchi, A; Valente, P; Venanzoni, G; Vescovi, S; Villa, F; Zanotti, G; Zema, N; Zobov, M

    2013-01-01

    This report describes the scientific aims and potentials as well as the preliminary technical design of IRIDE, an innovative tool for multi-disciplinary investigations in a wide field of scientific, technological and industrial applications. IRIDE will be a high intensity 'particle factory', based on a combination of a high duty cycle radio-frequency superconducting electron linac and of high energy lasers. Conceived to provide unique research possibilities for particle physics, for condensed matter physics, chemistry and material science, for structural biology and industrial applications, IRIDE will open completely new research possibilities and advance our knowledge in many branches of science and technology. IRIDE will contribute to open new avenues of discoveries and to address most important riddles: What does matter consist of? What is the structure of proteins that have a fundamental role in life processes? What can we learn from protein structure to improve the treatment of diseases and to design mor...

  17. First Operating Experiences of Beam Position Monitors in the TESLA Test Facility Linac

    Science.gov (United States)

    Lorenz, R.; Sachwitz, M.; Schreiber, H. J.; Tonisch, F.; Castellano, M.; Patteri, P.; Tazzioli, F.; Catani, L.

    1997-05-01

    Different types of monitors where installed in the TESLA Test Facility Linac to measure the beam position. At each superconducting quadrupole, the transverse beam position will be measured with a resolution of better than 10 μm, using a cylindrical cavity excited in the TM_110-mode by an off-center beam. In addition, two 'warm' cavities working at room temperature were built for the Injector I and the Bunch Compressor. The amplitude of the TM_110-mode and its phase are measured in a homodyne receiver. For the experimental area, stripline monitors having a resolution of better than 100 μm were built, tested and installed. The averaged position of the whole bunch train of Injector I is measured in a narrowband receiver using the amplitude-to-phase conversion. This paper summarizes the designs, cold tests and first operating experiences of both monitor types.

  18. Chromaticity of the lattice and beam stability in energy-recovery linacs

    Energy Technology Data Exchange (ETDEWEB)

    Litvinenko, V.N.

    2011-12-23

    Energy recovery linacs (ERLs) are an emerging generation of accelerators promising to revolutionize the fields of high-energy physics and photon sciences. These accelerators combine the advantages of linear accelerators with that of storage rings, and hold the promise of delivering electron beams of unprecedented power and quality. Use of superconducting radio-frequency (SRF) cavities converts ERLs into nearly perfect 'perpetuum mobile' accelerators, wherein the beam is accelerated to a desirable energy, used, and then gives the energy back to the RF field. One potential weakness of these devices is transverse beam break-up instability that could severely limit the available beam current. In this paper, I present a method of suppressing these dangerous effects using a natural phenomenon in the accelerators, viz., the chromaticity of the transverse motion.

  19. TESLA superconducting RF cavity development

    Energy Technology Data Exchange (ETDEWEB)

    Koepke, K. [Fermi National Accelerator Lab., Batavia, IL (United States); TESLA Collaboration

    1995-05-01

    The TESLA collaboration has made steady progress since its first official meeting at Cornell in 1990. The infrastructure necessary to assemble and test superconducting rf cavities has been installed at the TESLA Test Facility (TTF) at DESY. 5-cell, 1.3 GHz cavities have been fabricated and have reached accelerating fields of 25 MV/m. Full sized 9-cell copper cavities of TESLA geometry have been measured to verify the higher order modes present and to evaluate HOM coupling designs. The design of the TESLA 9-cell cavity has been finalized and industry has started delivery. Two prototype 9-cell niobium cavities in their first tests have reached accelerating fields of 10 MV/m and 15 MV/m in a vertical dewar after high peak power (HPP) conditioning. The first 12 m TESLA cryomodule that will house 8 9-cell cavities is scheduled to be delivered in Spring 1995. A design report for the TTF is in progress. The TTF test linac is scheduled to be commissioned in 1996/1997. (orig.).

  20. Start-To-End Simulations of the Energy Recovery Linac Prototype FEL

    CERN Document Server

    Gerth, Christopher; Muratori, Bruno; Owen, Hywel; Thompson, Neil R

    2004-01-01

    Daresbury Laboratory is currently building an Energy Recovery Linac Prototype (ERLP) that serves as a testbed for the study of beam dynamics and accelerator technology important for the design and construction of the proposed 4th Generation Light Source (4GLS) project. Two major objectives for the ERLP are the operation of an oscillator infra-red FEL and demonstration of energy recovery from an electron bunch with an energy spread induced by the FEL. In this paper we present start-to-end simulations including the FEL of the ERLP. The beam dynamics in the high-brightness injector, which consists of a DC photocathode gun and a super-conducting booster, have been modelled using the particle tracking code ASTRA. After the main linac, in which the particles are accelerated to 35 MeV, particles have been tracked with the code ELEGANT. The 3D code GENESIS was used to model the FEL interaction with the electron beam. Different modes of operation and their impact on the design of the ERLP are discussed.

  1. End-to-End Beam Dynamics Simulations for the ANL-RIA Driver Linac

    CERN Document Server

    Ostroumov, P N

    2004-01-01

    The proposed Rare Isotope Accelerator (RIA) Facility consists of a superconducting (SC) 1.4 GV driver linac capable of producing 400 kW beams of any ion from hydrogen to uranium. The driver is configured as an array of ~350 SC cavities, each with independently controllable rf phase. For the end-to-end beam dynamics design and simulation we use a dedicated code, TRACK. The code integrates ion motion through the three-dimensional fields of all elements of the driver linac beginning from the exit of the electron cyclotron resonance (ECR) ion source to the production targets. TRACK has been parallelized and is able to track large number of particles in randomly seeded accelerators with misalignments and a comprehensive set of errors. The simulation starts with multi-component dc ion beams extracted from the ECR. Beam losses are obtained by tracking up to million particles in hundreds of randomly seeded accelerators. To control beam losses a set of collimators is applied in designated areas. The end-to-end simulat...

  2. Beam-dynamics driven design of the LHeC energy-recovery linac

    Science.gov (United States)

    Pellegrini, Dario; Latina, Andrea; Schulte, Daniel; Bogacz, S. Alex

    2015-12-01

    The LHeC is envisioned as a natural upgrade of the LHC that aims at delivering an electron beam for collisions with the existing hadronic beams. The current baseline design for the electron facility consists of a multipass superconducting energy-recovery linac (ERL) operating in a continuous wave mode. The unprecedently high energy of the multipass ERL combined with a stringent emittance dilution budget poses new challenges for the beam optics. Here, we investigate the performances of a novel arc architecture based on a flexible momentum compaction lattice that mitigates the effects of synchrotron radiation while containing the bunch lengthening. Extensive beam-dynamics investigations have been performed with placet2, a recently developed tracking code for recirculating machines. They include the first end-to-end tracking and a simulation of the machine operation with a continuous beam. This paper briefly describes the Conceptual Design Report lattice, with an emphasis on possible and proposed improvements that emerged from the beam-dynamics studies. The detector bypass section has been integrated in the lattice, and its design choices are presented here. The stable operation of the ERL with a current up to ˜150 mA in the linacs has been validated in the presence of single- and multibunch wakefields, synchrotron radiation, and beam-beam effects.

  3. MASTER OT J190519.41+301524.4: New Eclipsing Cataclysmic Variable of VY Scl Type

    CERN Document Server

    Martinelli, F

    2016-01-01

    MASTER OT J190519.41+301524.4 was discovered as an optical transient of 15.7m by the Mobile Astronomical System of TElescope-Robots in March 2014. We report the results of photometric observations of this variable performed at Lajatico Astronomical Center in June-July 2015. The light curve is showing deep V-shaped eclipses with an amplitude of two magnitudes. The orbital period was determined to be 0.129694 d (3.113 h). Based on the archival observations and the shape of the orbital curve we suggest that MASTER OT J190519.41+301524.4 is a new cataclysmic variable of VY Scl type ("anti-nova") with an inclination angle close to 90 deg.

  4. Exploratory Factor Analysis of SCL90-R Symptoms Relevant to Psychosis

    Directory of Open Access Journals (Sweden)

    Javad Amini

    2011-10-01

    Full Text Available "nObjective: Inconsistent results have been reported regarding the symptom dimensions relevant to psychosis in symptoms check list revised (SCL90-R, i.e., "psychoticism" and "paranoid ideation". Therefore, some studies have suggested different factor structures for questions of these two dimensions, and proposed two newly defined dimensions of "schizotypal signs" and "schizophrenia nuclear symptoms". We conducted an exploratory factor analysis on the items of these two dimensions in a general population sample in Iran. "nMethod: A total of 2158 subjects residing in Southern Tehran (capital of Iran were interviewed using the psychoticism and paranoid ideation questions in SCL90-R to assess severity of these symptom dimensions. Factor analysis was done through SAS 9.1.3 PROC FACTOR using Promax rotation (power=3 on the matrix of "polychoric correlations among variables" as the input data. "nResults: Two factors were retained by the proportion criterion. Considering loadings >= 0.5 as minimum criteria for factor loadings, 7 out of 10 questions  from psychoticism ,and 3 out of 6 questions from paranoid ideation were retained, and others were eliminated. The factor labels proposed by the questionnaire suited the extracted factors and were retained. Internal consistency for each of the dimensions was acceptable (Cronbach's alpha 0.7 and 0.74 for paranoid ideation and psychoticism respectively. Composite scores showed a half-normal distribution for both dimensions which is predictable for instruments that detect psychotic symptoms. "nConclusion: Results were in contrast with similar studies, and questioned them by suggesting a different factor structure obtained from a statistically large population. The population in a developing nation (Iran in this study and the socio-cultural differences in developed settings are the potential sources for discrepancies between this analysis and previous reports.

  5. Analysis of High Order Modes in 1.3 GHZ CW SRF Electron Linac for a Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Sukhanov, A. [Fermilab; Vostrikov, A. [Fermilab; Yakovlev, V. [Fermilab

    2013-01-01

    Design of a Light Source (LS) based on the continuous wave superconducting RF (CW SRF) electron linac is currently underway. This facility will provide soft coherent X-ray radiation for a braod spectrum of basic research applications. Quality of the X-ray laser radiation is affected by the electron beam parameters such as the stability of the transverse beam position and longitudinal and transverse beam emittances. High order modes (HOMs) excited in the SRF structures by a passing beam may deteriorate the beam quality and affect the beam stability. Deposition of HOM energy in the walls of SRF cavities adds to the heat load of he cryogenic system and leads to the increased cost of building and operation of the linac. In this paper we evaluate effects of HOMs in an LS CW SRF linac based on Tesla-type 9-cell 1.3 GHz cavities. We analyze non-coherent losses and resonance excitation of HOMs. We estimate heat load due to the very high frequency HOMs. We study influence of the HOMs on the transverse beam dynamics.

  6. A Pencil Beam for the Linac4 commissioning

    CERN Document Server

    Lallement, JB

    2010-01-01

    In order to characterize the different accelerating structures and transport lines of Linac4 and to proceed to its commissioning, we need to produce a low current, low emittance beam. This note describes the generation of two pencil beams and their dynamic through the Linac.

  7. MEIC Proton Beam Formation with a Low Energy Linac

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yuhong [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

    2015-09-01

    The MEIC proton and ion beams are generated, accumulated, accelerated and cooled in a new green-field ion injector complex designed specifically to support its high luminosity goal. This injector consists of sources, a linac and a small booster ring. In this paper we explore feasibility of a short ion linac that injects low-energy protons and ions into the booster ring.

  8. Photonuclear reactions with zinc : A case for clinical linacs

    NARCIS (Netherlands)

    Boztosun, I.; Dapo, H.; Karakoc, M.; Ozmen, S. F.; Cecen, Y.; Coban, A.; Caner, T.; Bayram, E.; Saito, T. R.; Akdogan, T.; Bozkurt, V.; Kucuk, Y.; Kaya, D.; Harakeh, M. N.

    2015-01-01

    The use of bremsstrahlung photons produced by a linac to induce photonuclear reactions is wide spread. However, using a clinical linac to produce the photons is a new concept. We aimed to induce photonuclear reactions on zinc isotopes and measure the subsequent transition energies and half-lives. Fo

  9. Calibration of Super-Kamiokande Using an Electron Linac

    CERN Document Server

    Fukuda, Y; Ichihara, E; Inoue, K; Ishihara, K; Ishino, H; Itow, Y; Kajita, T; Kameda, J; Kasuga, S; Kobayashi, K; Kobayashi, Y; Koshio, Y; Martens, K; Miura, M; Nakayama, S; Okada, A; Okumura, K; Sakurai, N; Shiozawa, M; Suzuki, Y; Takeuchi, Y; Totsuka, Y; Yamada, S; Earl, M; Habig, A; Kearns, E; Messier, M D; Scholberg, K; Stone, J L; Sulak, L R; Walter, C W; Goldhaber, M; Barszczak, T; Casper, D; Gajewski, W; Halverson, P G; Hsu, J; Kropp, W R; Price, L R; Reines, F; Smy, M B; Sobel, H W; Vagins, M R; Ganezer, K S; Keig, W E; Ellsworth, R W; Tasaka, S; Flanagan, J W; Kibayashi, A; Learned, J G; Matsuno, S; Stenger, V J; Takemori, D; Ishii, T; Kanzaki, J; Kobayashi, T; Mine, S; Nakamura, K; Nishikawa, K; Oyama, Y; Sakai, A; Sakuda, M; Sasaki, O; Echigo, S; Kohama, M; Suzuki, A T; Haines, T J; Blaufuss, E; Kim, B K; Sanford, R; Svoboda, R; Chen, M L; Conner, Z; Goodman, J A; Sullivan, G W; Hill, J; Jung, C K; Mauger, C; McGrew, C; Sharkey, E; Viren, B; Yanagisawa, C; Doki, W; Miyano, K; Okazawa, H; Saji, C; Takahata, M; Nagashima, Y; Takita, M; Yamaguchi, T; Yoshida, M; Kim, S B; Etoh, M; Fujita, K; Hasegawa, A; Hasegawa, T; Hatakeyama, S; Iwamoto, T; Koga, M; Maruyama, T; Ogawa, H; Shirai, J; Suzuki, A; Tsushima, F; Koshiba, M; Nemoto, M; Nishijima, K; Futagami, T; Hayato, Y; Kanaya, Y; Kaneyuki, K; Watanabe, Y; Kielczewska, D; Doyle, R A; George, J S; Stachyra, A L; Wai, L L; Wilkes, R J; Young, K K; Kobayashi, H

    1999-01-01

    In order to calibrate the Super-Kamiokande experiment for solar neutrino measurements, a linear accelerator (LINAC) for electrons was installed at the detector. LINAC data were taken at various positions in the detector volume, tracking the detector response in the variables relevant to solar neutrino analysis. In particular, the absolute energy scale is now known with less than 1 percent uncertainty.

  10. Beam energy online measurement of BEPCII LINAC

    CERN Document Server

    Wang, Shao-Zhe; Chi, Yun-Long

    2015-01-01

    This paper describes beam energy online measurement of BEPCII linac, presents the calculation formula and some of the results. The method mentioned here measures the beam energy by acquiring beam positions in the horizontal direction with three beam position monitors (BPM) eliminating the effect of orbit fluctuation, which is much better than the one using the single BPM. The error analysis indicates that this online measurement has further potential usage such as a part of beam energy feedback system. The reliability of this method is also discussed and demonstrated in the end of this paper.

  11. RF Breakdown in Drift Tube Linacs

    CERN Document Server

    Stovall, J; Lown, R

    2009-01-01

    The highest RF electric field in drift-tube linacs (DTLs) often occurs on the face of the first drift tube. Typically this drift tube contains a quadrupole focusing magnet whose fringing fields penetrate the face of the drift tube parallel to the RF electric fields in the accelerating gap. It has been shown that the threshold for RF breakdown in RF cavities may be reduced in the presence of a static magnetic field. This note offers a “rule of thumb” for picking the maximum “safe” surface electric field in DTLs based on these measurements.

  12. Obese Female College Students:Their Personality Traits and SCL-90 Results%肥胖女大学生的个性特征和SCL-90测试结果及分析

    Institute of Scientific and Technical Information of China (English)

    王云飞; 张妮

    2016-01-01

    运用问卷调查法和数理统计法对湖南3所高校的180名肥胖女大学生和正常女大学生进行个性特征和SCL-90测试分析,研究发现:肥胖女大学生个性特征中的情绪性、倔强性和SCL-90测试结果明显高于正常体重的女大学生,这表明肥胖女大学生因为体形肥胖而易于出现个性特征异常,从而引发心理健康问题。%Using mathematical statistics and SCL-90 Symptom Check List, the author studies the personality traits of 180 female college students. Some of them are overweight, and some have normal weight. The study shows that the overweight female college students are more emotional and obstinate and have higher scores in SCL-90 than those with normal weight. This suggests that female college students tend to have abnormal personality traits due to obesity and thus suffer from psychological problems.

  13. Cloning and Analysis of Autotoxicity Related Gene CmSCL13 in Melon%甜瓜自毒作用相关基因 CmSCL13的克隆及表达分析

    Institute of Scientific and Technical Information of China (English)

    谢新蕊; 张志忠

    2014-01-01

    The differential fragment of scarecrow-like protein 13-like (SCL13) was separated by the cD-NA-AFLP technique from the leaves of melon , which was associated with autotoxicity .‘New Silverlit ’ was cloned by RACE technology .The full-length cDNA sequence of CmSCL13 had an ORF of 1 623 bp and enco-ded 541 amino acids .Its amino acid was searched by the NCBI Conserved Domain Search ,which indicated that the gene had conserved domain of GRAS family .Therefore , the gene of melon could be named as CmSCL13 ( GenBank accession number:KF134812 ) .The result showed that this fragment was highly associated with SCL13 genes of cucumber .Fluorescence quantitative PCR method was used to study the expression characteris-tics of GRAS gene in melon under root exudates stress ,and the result showed that the gene expression changed after root exudates treatment ,which was consistent with the results of cDNA-AFLP .%以甜瓜品种“新银辉”为试验材料,利用cDNA-AFLP技术分离并获取了甜瓜自毒作用相关scarecrow-like protein 13-like ( SCL13)片段序列,利用RACE技术获得该基因全长cDNA序列,包含有1623 bp的完整阅读框,编码541个氨基酸。在NCBI上通过Conserved Domain Search 对该基因编码的氨基酸进行搜索,表明该基因具有GRAS家族特有的保守结构域,命名为:CmSCL13( GenBank登录号:KF134812)。 Blastn分析显示该基因与黄瓜CsSCL13基因同源性较高;荧光定量PCR分析结果显示该基因随胁迫处理时间延长表达量呈上调趋势,该结果也与cDNA-AFLP的结果相一致。

  14. Photon and photoneutron spectra produced in radiotherapy Linacs

    Energy Technology Data Exchange (ETDEWEB)

    Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico); Martinez O, S. A. [Universidad Pedagogica y Tecnologica de Colombia, Grupo de Fisica Nuclear Aplicada y Simulacion, Av. Central del Norte Km. 1, Via Paipa Tunja, Boyaca (Colombia); Benites R, J. L. [Universidad Autonoma de Nayarit, Postgrado CBAP, Carretera Tepic Compostela Km. 9, Xalisco, Nayarit (Mexico); Lallena, A. M., E-mail: fermineutron@yahoo.com [Universida de Granada, Departamento de Fisica Atomica, Molecular y Nuclear, E-18071 Granada (Spain)

    2011-10-15

    A Monte Carlo calculation, using the MCNPX code, was carried out in order to estimate the photon and neutron spectra in two locations of two linacs operating at 15 and 18 MV. Detailed models of both linac heads were used in the calculations. Spectra were estimated below the flattening filter and at the isocenter. Neutron spectra show two components due to evaporation and knock-on neutrons. Lethargy spectra under the filter were compared to the spectra calculated from the function quoted by Tosi et al. that describes reasonably well neutron spectra beyond 1 MeV, though tends to underestimate the energy region between 10{sup -6} and 1 MeV. Neutron and Bremsstrahlung spectra show the same features regardless of the linac voltage. The amount of photons and neutrons produced by the 15 MV linac is smaller than that found for the 18 MV linac. As expected, Bremsstrahlung spectra ends according to the voltage used to accelerate the electrons. (Author)

  15. Range of Possible Beam Current in Linac4

    CERN Document Server

    Lallement, J-B; CERN. Geneva. BE Department

    2009-01-01

    Linac4 is a new accelerator under construction at CERN. It is designed to accelerate H- ions to 160MeV, for injection into the existing Proton Synchrotron Booster (PSB). It is also the front-end of the SPL Linac, a high energy proton driver that will reach the energy of 5GeV. The Linac baseline design has been done for a nominal beam peak current of 70mA but it will certainly have to deal with different currents. 132 out of 155 quadrupoles in the Linac are permanent magnets, this choice of using PMQ having fixed gradient, mainly in the DTL and in the CCDTL may then entail issues concerning the beam transverse matching and quality from current different from the nominal one. In this paper, we present the beam dynamics performances in Linac4 obtained for different currents.

  16. The Pre-Injector Linac for the Diamond Light Source

    CERN Document Server

    Christou, C

    2004-01-01

    The Diamond Light Source is a new medium-energy high brightness synchrotron light facility which is under construction on the Rutherford Appleton Laboratory site in the U.K. The accelerator facility can be divided into three major components; a 3 GeV 561 m circumference storage ring, a full-energy booster synchrotron and a 100 MeV pre-injector linac. This paper describes the linac design and plans for operation. The linac is supplied by ACCEL Instruments GmbH under a turn-key contract, with Diamond Light Source Ltd. providing linac beam diagnostics, control system hardware and standard vacuum components. Commissioning of the linac will take place in early 2005 and user operation of the facility will commence in 2007.

  17. A coaxial HOM coupler for a superconducting RF cavity and its low-power measurement results

    Institute of Scientific and Technical Information of China (English)

    SUN An; TANG Ya-Zhe; ZHANG Li-Ping; LI Ying-Min; Han-Sung Kim

    2011-01-01

    A resonant buildup of beam-induced fields in a superconducting radio frequency(RF)cavity may make a beam unstable or a superconducting RF cavity quench. Higher-order mode(HOM)couplers are used for damping higher-order modes to avoid such a resonant buildup. A coaxial HOM coupler based on the TTF (TESLA Test Facility)HOM coupler has been designed for the superconducting RF cavities at the Proton Engineering Frontier Project(PEFP)in order to overcome notch frequency shift and feed-through tip melting issues. In order to confirm the HOM coupler design and finalize its structural dimensions, two prototype HOM couplers have been fabricated and tested. Low-power testing and measurement of the HOM couplers has shown that the HOM coupler has good filter properties and can fully meet the damping requirements of the PEFP low-beta superconducting RF linac.

  18. A Description Method of IEC 61850 SCL ScheMa File Based on CIM/E%一种基于CIM/E的IEC 61850 SCL ScheMa文件描述方法

    Institute of Scientific and Technical Information of China (English)

    刁东宇; 翟明玉; 王海峰; 梅德冬

    2016-01-01

    This paper introduces a description method of IEC 61850 SCL Schema file based on CIM/E lan-guage. Class template definition function of CIM/E language is used in this method to define description format of the entity classes and analyze the UML class diagram in the four major parts of the information defined in the SCL language, including communication, substation, IED and data type template. In accordance with the principles of property inheritance and implementation simplification, the method redefines the class descrip-tion format by defining description format of entity classes and generates the IEC 61850 SCL schema file based on CIM/E language for the sake of model unification in substation and dispatching point.%提供了一种基于CIM/E语言的IEC 61850 SCL Schema文件描述方法,该方法采用CIM/E语言的类模板定义功能,自定义实体类描述格式,对SCL语言中主要定义的4部分信息,包括通信类、一次设备类、智能电子设备类、数据类型模板类的UML类图进行类图分析,按照属性继承和简化实现的原则,采用自定义实体类描述格式对其进行再描述,生成基于CIM/E语言描述的IEC 61850 SCL Schema文件,以解决变电站和调度端模型不统一的问题。

  19. Cryogenic safety of the superconducting ALPI accelerator at INFN-LNL

    CERN Document Server

    CERN. Geneva

    2016-01-01

    The superconducting linac ALPI at INFN-LNL is composed of 20 identical cryostats housing, at a group of four (or two), 74 superconducting QWR type cavities: 58 resonators are made of copper with Nb sputtered on the internal surface and 16 are made of Nb bulk. In each cryostat is installed a 100 liter volume LHe reservoir feeding by gravity the QWR’s. The thermal shield around is cooled by GHe at 6 bar abs at 60-80 K. The linac ALPI is a post-accelerator which can receive heavy ions from either the 16 MV Tandem Van de Graaf or from the superconducting injector PIAVE. The latter is composed by an ECR source, two superconducting RFQ, and two cryostats each containg four superconducting bulk Nb QWR. The ALPI cryostats are cooled by a Helium refrigerator whose refrigerator capacity is 1200 W at 4.5 K and 3900 W additional at 60-80 K. PIAVE cryostats are cooled by a separate TCF50 helium refrigerator. The complex ALPI-PIAVE is installed in a semi-open removable concrete tunnel in the same building where the two h...

  20. Simple Superconducting "Permanent" Electromagnet

    Science.gov (United States)

    Israelson, Ulf E.; Strayer, Donald M.

    1992-01-01

    Proposed short tube of high-temperature-superconducting material like YBa2Cu3O7 acts as strong electromagnet that flows as long as magnetic field remains below critical value and temperature of cylinder maintained sufficiently below superconducting-transition temperature. Design exploits maximally anisotropy of high-temperature-superconducting material.

  1. Basic principle of superconductivity

    OpenAIRE

    De Cao, Tian

    2007-01-01

    The basic principle of superconductivity is suggested in this paper. There have been two vital wrong suggestions on the basic principle, one is the relation between superconductivity and the Bose-Einstein condensation (BEC), and another is the relation between superconductivity and pseudogap.

  2. Doing Textiles Experiments in Game-Based Virtual Reality: A Design of the Stereoscopic Chemical Laboratory (SCL) for Textiles Education

    Science.gov (United States)

    Lau, Kung Wong; Kan, Chi Wai; Lee, Pui Yuen

    2017-01-01

    Purpose: The purpose of this paper is to discuss the use of stereoscopic virtual technology in textile and fashion studies in particular to the area of chemical experiment. The development of a designed virtual platform, called Stereoscopic Chemical Laboratory (SCL), is introduced. Design/methodology/approach: To implement the suggested…

  3. Linac-driven spallation-neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Jason, A.J.

    1995-05-01

    Strong interest has arisen in accelerator-driven spallation-neutron sources that surpass existing facilities (such as ISIS at Rutherford or LANSCE at Los Alamos) by more than an order of magnitude in beam power delivered to the spallation target. The approach chosen by Los Alamos (as well as the European Spallation Source) provides the full beam energy by acceleration in a linac as opposed to primary acceleration in a synchrotron or other circular device. Two modes of neutron production are visualized for the source. A short-pulse mode produces 1 MW of beam power (at 60 pps) in pulses, of length less than 1 ms, by compression of the linac macropulse through multi-turn injection in an accumulator ring. A long-pulse mode produces a similar beam power with 1-ms-long pulses directly applied to a target. This latter mode rivals the performance of existing reactor facilities to very low neutron energies. Combination with the short-pulse mode addresses virtually all applications.

  4. Production of Medical Isotopes with Electron Linacs

    Energy Technology Data Exchange (ETDEWEB)

    Rotsch, D A; Alford, K.; Bailey, J. L.; Bowers, D. L.; Brossard, T.; Brown, M. A.; Chemerisov, S. D.; Ehst, D.; Greene, J.; Gromov, R. G.; Grudzinski, J.J.; Hafenrichter, L.; Hebden, A. S.; Henning, W.; Heltemes, T. A.; Jerden, J.; Jonah, C. D.; Kalensky, M.; Krebs, J. F.; Makarashvili, V.; Micklich, B.; Nolen, J.; Quigley, K. J.; Schneider, J. F.; Smith, N. A.; Stepinski, D. C.; Sun, Z.; Tkac, P.; Vandegrift, G. F.; Virgo, M J; Wesolowski, K. A.; Youker, A. J.

    2017-06-01

    Radioisotopes play important roles in numerous areas ranging from medical treatments to national security and basic research. Radionuclide production technology for medical applications has been pursued since the early 1900s both commercially and in nuclear science centers. Many medical isotopes are now in routine production and are used in day-to-day medical procedures. Despite these advancements, research is accelerating around the world to improve the existing production methodologies as well as to develop novel radionuclides for new medical appli-cations. Electron linear accelerators (linacs) represent a unique method for the production of radioisotopes. Even though the basic technology has been around for decades, only recently have electron linacs capable of producing photons with sufficient energy and flux for radioisotope production become available. Housed in Argonne Nation-al Laboratory’s Low Energy Accelerator Facility (LEAF) is a newly upgraded 55 MeV/25-kW electron linear ac-celerator, capable of producing a wide range of radioiso-topes. This talk will focus on the work being performed for the production of the medical isotopes 99Mo (99Mo/99mTc generator), 67Cu, and 47Sc.

  5. Mapping and functional characterisation of a CTCF-dependent insulator element at the 3' border of the murine Scl transcriptional domain.

    Directory of Open Access Journals (Sweden)

    George A Follows

    Full Text Available The Scl gene encodes a transcription factor essential for haematopoietic development. Scl transcription is regulated by a panel of cis-elements spread over 55 kb with the most distal 3' element being located downstream of the neighbouring gene Map17, which is co-regulated with Scl in haematopoietic cells. The Scl/Map17 domain is flanked upstream by the ubiquitously expressed Sil gene and downstream by a cluster of Cyp genes active in liver, but the mechanisms responsible for delineating the domain boundaries remain unclear. Here we report identification of a DNaseI hypersensitive site at the 3' end of the Scl/Map17 domain and 45 kb downstream of the Scl transcription start site. This element is located at the boundary of active and inactive chromatin, does not function as a classical tissue-specific enhancer, binds CTCF and is both necessary and sufficient for insulator function in haematopoietic cells in vitro. Moreover, in a transgenic reporter assay, tissue-specific expression of the Scl promoter in brain was increased by incorporation of 350 bp flanking fragments from the +45 element. Our data suggests that the +45 region functions as a boundary element that separates the Scl/Map17 and Cyp transcriptional domains, and raise the possibility that this element may be useful for improving tissue-specific expression of transgenic constructs.

  6. The elbe accelerator facility starts operation with the superconducting rf gun

    CERN Document Server

    Xiang, R; Buettig, H; Janssen, D; Justus, M; Lehnert, U; Michel, P; Murcek, P; Schneider, C; Schurig, R; Staufenbiel, F; Teichert, J; Kamps, T; Rudolph, J; Schenk, M; Klemz, G; Will, I

    2010-01-01

    As the first superconducting rf photo-injector (SRF gun) in practice, the FZD 3+1/2 cell SRF gun is successfully connected to the superconducting linac ELBE. This setting will improve the beam quality for ELBE users. It is the first example for an accelerator facility fully based on superconducting RF technology. For high average power FEL and ERL sources, the combination of SRF linac and SRF gun provides a new chance to produce beams of high average current and low emittance with relative low power consumption. The main parameters achieved from the present SRF gun are the final electron energy of 3 MeV, 16 μA average current, and rms transverse normalized emittances of 3 mm mrad at 77 pC bunch charge. A modified 3+1/2 cell niobium cavity has been fabricated and tested, which will increase the rf gradient in the gun and thus better the beam parameters further. In this paper the status of the integration of the SRF gun with the ELBE linac will be presented, and the latest results of the beam experiments will ...

  7. PHYSICS RESULTS OF THE NSLS-II LINAC FRONT END TEST STAND

    Energy Technology Data Exchange (ETDEWEB)

    Fliller R. P.; Gao, F.; Yang, X.; Rose, J.; Shaftan, T.; Piel, C

    2012-05-20

    The Linac Front End Test Stand (LFETS) was installed at the Source Development Laboratory (SDL) in the fall of 2011 in order to test the Linac Front End. The goal of these tests was to test the electron source against the specifications of the linac. In this report, we discuss the results of these measurements and the effect on linac performance.

  8. Characterization of Superconducting Cavities for HIE-ISOLDE

    CERN Document Server

    Martinello, Martina

    2013-01-01

    In this report the radiofrequency measurements done for the superconducting cavities developed at CERN for the HIE-ISOLDE project are analyzed. The purpose of this project is improve the energy of the REX-ISOLDE facility by means of a superconducting LINAC. In this way it will be possible to reach higher accelerating gradients, and so higher particle energies (up to 10MeV/u). At this purpose the Niobium thin film technology was preferred to the Niobium bulk technology because of the technical advantages like the higher thermal conductivity of Copper and the higher stiffness of the cavities which are less sentitive to mechanical vibrations. The Niobium coating is being optimized on test prototypes which are qualified by RF measurements at cold.

  9. Superconductivity in Medicine

    Science.gov (United States)

    Alonso, Jose R.; Antaya, Timothy A.

    2012-01-01

    Superconductivity is playing an increasingly important role in advanced medical technologies. Compact superconducting cyclotrons are emerging as powerful tools for external beam therapy with protons and carbon ions, and offer advantages of cost and size reduction in isotope production as well. Superconducting magnets in isocentric gantries reduce their size and weight to practical proportions. In diagnostic imaging, superconducting magnets have been crucial for the successful clinical implementation of magnetic resonance imaging. This article introduces each of those areas and describes the role which superconductivity is playing in them.

  10. Enhanced superconductivity of fullerenes

    Energy Technology Data Exchange (ETDEWEB)

    Washington, II, Aaron L.; Teprovich, Joseph A.; Zidan, Ragaiy

    2017-06-20

    Methods for enhancing characteristics of superconductive fullerenes and devices incorporating the fullerenes are disclosed. Enhancements can include increase in the critical transition temperature at a constant magnetic field; the existence of a superconducting hysteresis over a changing magnetic field; a decrease in the stabilizing magnetic field required for the onset of superconductivity; and/or an increase in the stability of superconductivity over a large magnetic field. The enhancements can be brought about by transmitting electromagnetic radiation to the superconductive fullerene such that the electromagnetic radiation impinges on the fullerene with an energy that is greater than the band gap of the fullerene.

  11. Superconducting microfabricated ion traps

    CERN Document Server

    Wang, Shannon X; Labaziewicz, Jaroslaw; Dauler, Eric; Berggren, Karl; Chuang, Isaac L

    2010-01-01

    We fabricate superconducting ion traps with niobium and niobium nitride and trap single 88Sr ions at cryogenic temperatures. The superconducting transition is verified and characterized by measuring the resistance and critical current using a 4-wire measurement on the trap structure, and observing change in the rf reflection. The lowest observed heating rate is 2.1(3) quanta/sec at 800 kHz at 6 K and shows no significant change across the superconducting transition, suggesting that anomalous heating is primarily caused by noise sources on the surface. This demonstration of superconducting ion traps opens up possibilities for integrating trapped ions and molecular ions with superconducting devices.

  12. Superconducting material development

    Science.gov (United States)

    1987-09-01

    A superconducting compound was developed that showed a transition to a zero-resistance state at 65 C, or 338 K. The superconducting material, which is an oxide based on strontium, barium, yttrium, and copper, continued in the zero-resistance state similar to superconductivity for 10 days at room temperature in the air. It was also noted that measurements of the material allowed it to observe a nonlinear characteristic curve between current and voltage at 65 C, which is another indication of superconductivity. The research results of the laboratory experiment with the superconducting material will be published in the August edition of the Japanese Journal of Applied Physics.

  13. Protective link for superconducting coil

    Science.gov (United States)

    Umans, Stephen D.

    2009-12-08

    A superconducting coil system includes a superconducting coil and a protective link of superconducting material coupled to the superconducting coil. A rotating machine includes first and second coils and a protective link of superconducting material. The second coil is operable to rotate with respect to the first coil. One of the first and second coils is a superconducting coil. The protective link is coupled to the superconducting coil.

  14. Update of the Linac4-PSB Transfer Line

    CERN Document Server

    HEIN, Lutz

    2010-01-01

    The installation of Linac4 represents the first step of the upgrade plans of the CERN accelerator complex for the future in order to raise the available proton flux to attain amongst others the LHC ultimate luminosity. This linac is capable to accelerate H--ions from 45keV to 160MeV, which will be injected into the Proton Synchrotron Booster (PSB). The increase of energy from 50MeV (Linac2) to 160MeV (Linac4) allows to overcome the space charge limitations at the PSB injection, which is the main bottleneck towards higher beam brightness in the downstream accelerator chain. In order to preserve beam quality from the outlet of Linac4 to PSB injection the design of the transfer line becomes crucial. As the location of Linac4 was chosen in view of upgrade scenarios, the construction of a new transfer line is foreseen, see ref.[1] and ref.[2]. Here part of the Linac2-PSB transfer line will be re-used. In the new part of the transfer line the beam is horizontally and vertically adjusted towards the bending magnet B...

  15. First Linac4 DTL & CCDTL cavities installed in tunnel

    CERN Multimedia

    Katarina Anthony

    2014-01-01

    On 5 June, the first Drift Tube Linac (DTL) was successfully transported to its forever home in the Linac4 tunnel. Similarly, the first Cell-Coupled Drift Tube Linac (CCDTL) was installed on 6 June. These moves marked the end of years of design and manufacturing by Linac4 teams.   Although it may seem like a relatively routine transport operation, the DTL's move was a landmark event for the entire Linac4 collaboration. "Along with the first four Cell-Coupled DTL modules, which were installed on the following two working days, these are the first accelerating structures after front-end commissioning to be installed in the tunnel," says Frank Gerigk, who is responsible for all Linac4 accelerating structures. "It is a major milestone, because work on all these structures started well over a decade ago." The transport operation was also quite a victory for the Linac4 DTL team, whose journey to a complete DTL structure has been a bit of a wild ride. &qu...

  16. Linac4 crosses the 100 MeV threshold

    CERN Multimedia

    Corinne Pralavorio

    2016-01-01

    The new linear accelerator, which from 2020 will be the first link in the accelerator chain, has entered a new stage of its commissioning.   Members of the team in charge of the commissioning of Linac4 in the accelerator’s control room. A few hours earlier, Linac4 accelerated a beam to 107 MeV for the first time. We couldn’t have imagined a more appropriate date: on 1 July (1.07), Linac4 reached an energy of 107 MeV. Having crossed the 100 MeV barrier, the linear accelerator is now on the home straight of its commissioning. “This stage was very quick – it took less than two weeks,” says Alessandra Lombardi, deputy project leader of Linac4, in charge of the commissioning. In 2020, Linac4 will replace the existing Linac2 as the first link in the accelerator chain. It will accelerate beams of H- ions (protons surrounded by two electrons) to 160 MeV, compared to 50 MeV with Linac2. The new machine is particularly sophisticated as it comprises...

  17. Superconductivity in transition metals.

    Science.gov (United States)

    Slocombe, Daniel R; Kuznetsov, Vladimir L; Grochala, Wojciech; Williams, Robert J P; Edwards, Peter P

    2015-03-13

    A qualitative account of the occurrence and magnitude of superconductivity in the transition metals is presented, with a primary emphasis on elements of the first row. Correlations of the important parameters of the Bardeen-Cooper-Schrieffer theory of superconductivity are highlighted with respect to the number of d-shell electrons per atom of the transition elements. The relation between the systematics of superconductivity in the transition metals and the periodic table high-lights the importance of short-range or chemical bonding on the remarkable natural phenomenon of superconductivity in the chemical elements. A relationship between superconductivity and lattice instability appears naturally as a balance and competition between localized covalent bonding and so-called broken covalency, which favours d-electron delocalization and superconductivity. In this manner, the systematics of superconductivity and various other physical properties of the transition elements are related and unified.

  18. Injection schemes for the TOP Linac; Schemi di iniezione per il TOP Linac

    Energy Technology Data Exchange (ETDEWEB)

    Picardi, L.; Ronsivalle, C. [ENEA, Centro Ricerche Frascati, Frascati, RM (Italy). Dipt. Innovazione; Bartolini, R. [Istituto Superiore di Sanita' , Rome (Italy)

    1999-07-01

    In this report two schemes are studied for the injection in the SCDTL section of the TOP Linac of the proton beam produced by a 7 MeV linear accelerator. The project derives by an agreement between ENEA (National Agency for New Technology, Energy and Environment) and ISS. In these new versions of the design the constraint of a synchronization of the radio frequencies of the two accelerators is suppressed. [Italian] In questo rapporto sono studiati due schemi di iniezione nella sezione accelerante SCDTL a 3 GHz del TOP (terapia oncologica con protoni) linac del fascio di protoni generato da un acceleratore lineare di 7 MeV. L'acceleratore e' frutto di una convenzione tra L'ENEA e l'Istituto Superiore di Sanita'. Rispetto a versioni precedenti del progetto, viene eliminato il vincolo della sincronizzazione delle radiofrequenze dei due acceleratori.

  19. Performance of EVA-Based Membranes for SCL in Hard Rock

    Science.gov (United States)

    Holter, Karl Gunnar

    2016-04-01

    The bonded property of multi-layered sprayed concrete tunnel linings (SCL) waterproofed with sprayed membranes means that the constituent materials will be exposed to the groundwater without any draining or mechanically separating measures. Moisture properties of the sprayed concrete and membrane materials are therefore important in order to establish the system properties of such linings. Ethyl-vinyl-acetate based sprayed membranes exhibit high water absorption potential under direct exposure to water, but are found to be significantly less hygroscopic and exhibit lower sorptivity (water absorption rate) than sprayed concrete. This material behavior explains the relatively dry in situ condition of the membrane that was observed. Measured in situ moisture content levels of the membrane material in tunnel linings have been found to vary within the range of 30-40 % of the maximum water absorption potential, and show a decreasing trend over the first 4 years after construction has been completed. A model for the mechanical loading, moisture condition and thermal exposure of the membrane and the resulting realistic parameters to be tested is presented. Laboratory testing methods for the membrane materials are evaluated considering possible loads, moisture and freezing exposure. Material testing of membrane materials was conducted with preconditioning to realistic moisture contents and under different temperature conditions including relevant freezing temperatures for tunnel linings. The main effects of the in situ moisture condition of the tested membrane materials are favorable tensile strengths in the range of 1.1-1.5 MPa and low risk of freeze-thaw damage. The crack bridging capacity of the tested membranes is found to be sensitive to temperature. With membrane thicknesses in the range of 3-4 mm, crack bridging capacity up to 4-6 mm opening of the crack width at 23 °C and approximately 1 mm opening at -3 °C was measured for the tested membranes. No significant

  20. Status of high current R&D Energy Recovery LINAC at Brookhaven National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Kayran, D.; Altinbas Z.; Beavis D.; Ben-Zvi I.; Calaga R.; Gassner D.M.; Hahn H.; Hammons L.; Jain A.; Jamilkowski J.; Lambiase R.; Lederle D.; Litvinenko V.N.; Laloudakis N.; Mahler G.; McIntyre G.; Meng W.; Oerter B.; Pate D.; Phillips D.; Reich J.; Roser T.; Schultheiss C.; Seda T.; Sheehy B.; Srinivasan-Rao T.; Than R.; Tuozzolo J.; Weiss D.; Xu W.; Zaltsman A.

    2011-03-28

    An ampere class 20 MeV superconducting Energy Recovery Linac (ERL) is under construction at Brookhaven National Laboratory (BNL) for testing of concepts relevant for high-energy coherent electron cooling and electron-ion colliders. One of the goals is to demonstrate an electron beam with high charge per bunch ({approx} 5 nC) and low normalized emittance ({approx} 5 mm-mrad) at an energy of 20 MeV. Flexible lattice of ERL loop provides a test-bed for investigating issues of transverse and longitudinal instabilities, and diagnostics for intense CW e-beam. The superconducting 703 MHz RF photoinjector is considered as an electron source for such a facility. We will start with a straight pass (gun - 5 cell cavity - beam stop) test for the SRF Gun performance studies. Later, we will install and test a novel injection line concept for emittance preservation in a lower energy merger. In this paper we present the status and our plans for construction and commissioning of this facility.

  1. The Linac4 DTL Prototype: Low and High Power Measurements

    CERN Document Server

    De Michele, G; Marques-Balula, J; Ramberger, S

    2012-01-01

    The prototype of the Linac4 Drift Tube Linac (DTL) has undergone low power measurements in order to verify the RF coupling and to adjust the post-coupler lengths based on bead-pull and spectrum measurements. Following the installation at the test stand, the cavity has been subjected to high power operation at Linac4 and SPL duty cycles. Saturation effects and multipacting have been observed and linked to X-ray emission. Voltage holding is reported in the presence of magnetic fields from permanent magnet quadrupoles (PMQ) installed in the first drift tubes.

  2. Using basic electromagnetism to introduce LINAC4 (CERN)

    Science.gov (United States)

    Cid-Vidal, Xabier; Cid, Ramon; Vretenar, Maurizio

    2016-07-01

    The LHC is the last element of CERN’s accelerator complex, which is a succession of machines with increasingly higher energies. Everything starts in the 50 MeV linear accelerator (LINAC2), but a new linear accelerator, the 160 MeV LINAC4, will replace LINAC2 in 2018, upgrading LHC injectors to higher intensity and eventually increasing the luminosity of LHC. The aim of this article is briefly introducing this new accelerator, and presenting a simple application of some fundamental laws of magnetism to be taken to the secondary school classrooms.

  3. An induction linac developed for FEL application

    Science.gov (United States)

    de Mascureau, J.; Anthouard, Ph.; Bardy, J.; Eyharts, Ph.; Eyl, P.; Launspach, J.; Thevenot, M.; Villate, D.

    1992-07-01

    An induction linac is being studied and built at CESTA for FEL application. At first we studied the induction technology and namely the high-voltage (HV) generators and the induction cells. A HV generator designed to feed the cells with calibrated pulses (150 kV, 50 ns, δV/V magnetic switches. This generator is planned for kHz repetition-rate operation. A prototype induction cell has also been built and tested with a cable generator. An electron injector (1.5 MeV, 1.5kA) has been designed and is now under test: it uses ten induction cells and a thermionic dispenser cathode. Numerical codes have been developed and simulations have been compared with experimental results for HV generators, induction cells, and the injector. An induction accelerating module has been studied and we plan to have the accelerator working at 3 MeV in 1992.

  4. Sclérose latérale amyotrophique et traumatisme

    Directory of Open Access Journals (Sweden)

    M. Schachter

    1959-09-01

    Full Text Available À propos d'une deuxième observation personnelle de sclérose latérale amyotrophique d'origine traumatique, nous passons en revue les connaissances actuelles sur le chapitre de neuro-traumatologie. Dans l'observation présente le traumatisme cranien n'avait pas entrainé de perte de la connaissance; l'intervalle entre traumatisme et installation des premiers signes (à caractère bulbaire surtout fut de pratiquement un mois; mais on connaît des cas où cet intervalle a été de l'ordre de plusieurs années, comme dans notre première observation (15 ans. La relation entre traumatisme et maladie de Charcot est encore discutée, mais il est indubitable que ce facteur peut déclencher, à lui seul, cette maladie, sans que l'on doive faire intervenir d'autres facteurs pré-dispo-sants.

  5. The invention that shapes Linac4: Tolerance Aligned Cantileaver Mounting (TACM) system to build drift tube linacs

    CERN Multimedia

    CERN Video Productions

    2010-01-01

    Accelerator experts are no new to original optimizations of existing techniques and to the development of novel solutions. Sometimes, they even come up with ideas that have the potential to revolutionize the field. This was indeed the case for the Tolerance Aligned Cantilever Mounting (TACM) system, a completely new way of supporting the drift tubes, one of the core elements of linear accelerators. The new, patent-pending technique will be implemented at Linac4.Interview with Suitbert Ramberger, Project engineer for the Linac4 Drift Tube Linac (DTL).

  6. An integrated computer control system for the ANU linac

    Science.gov (United States)

    Davidson, P. M.; Foote, G. S.

    1996-02-01

    One facet of the installation of the superconducting linac at the ANU is the need for computer control of a variety of systems, such as beam transport, resonator RF, cryogenics and others. To accommodate this, a number of control interfaces (for example, analogue signals and RS232 serial lines) must be employed. Ideally, all of the systems should be able to be controlled from a central location, remote from the actual devices. To this end a system based around VAX computers and VME crates has been designed and is currently being developed and implemented. A VAXstation is used to issue control messages and perform high-level functions, while VME crates containing appropriate modules (primarily DACs, ADCs and digital I/O boards) control the devices. The controllers in the VME crates are AEON rtVAX modules running a real-time operating system. Communication with the VAXstation is via DECnet, on a private ethernet to allow communication rates unaffected by unrelated network activity and potentially increasing the security of the system by providing a possible network isolation point. Also on this ethernet are a number of terminal servers to control RS232 devices. A central database contains all device control and monitoring parameters. The main control process running on the VAXstation is responsible for maintaining the current values of the parameters in the database and for dispatching control messages to the appropriate VME crate or RS232 serial line. Separate graphical interface processes allow the operator to interact with the control process, communicating through shared memory. Many graphics processes can be active simultaneously, displaying either on a single or on multiple terminals. Software running on the rtVAX controllers handles the low-level device-specific control by translating messages from the main control process to VME commands which set hardware outputs on VME modules. Similarly, requests for the value of a parameter result in the rtVAX program

  7. SEUSS Integrates Gibberellin Signaling with Transcriptional Inputs from the SHR-SCR-SCL3 Module to Regulate Middle Cortex Formation in the Arabidopsis Root.

    Science.gov (United States)

    Gong, Xue; Flores-Vergara, Miguel A; Hong, Jing Han; Chu, Huangwei; Lim, Jun; Franks, Robert G; Liu, Zhongchi; Xu, Jian

    2016-03-01

    A decade of studies on middle cortex (MC) formation in the root endodermis of Arabidopsis (Arabidopsis thaliana) have revealed a complex regulatory network that is orchestrated by several GRAS family transcription factors, including SHORT-ROOT (SHR), SCARECROW (SCR), and SCARECROW-LIKE3 (SCL3). However, how their functions are regulated remains obscure. Here we show that mutations in the SEUSS (SEU) gene led to a higher frequency of MC formation. seu mutants had strongly reduced expression of SHR, SCR, and SCL3, suggesting that SEU positively regulates these genes. Our results further indicate that SEU physically associates with upstream regulatory sequences of SHR, SCR, and SCL3; and that SEU has distinct genetic interactions with these genes in the control of MC formation, with SCL3 being epistatic to SEU. Similar to SCL3, SEU was repressed by the phytohormone GA and induced by the GA biosynthesis inhibitor paclobutrazol, suggesting that SEU acts downstream of GA signaling to regulate MC formation. Consistently, we found that SEU mediates the regulation of SCL3 by GA signaling. Together, our study identifies SEU as a new critical player that integrates GA signaling with transcriptional inputs from the SHR-SCR-SCL3 module to regulate MC formation in the Arabidopsis root.

  8. Photonuclear reactions with Zinc: A case for clinical linacs

    CERN Document Server

    Boztosun, I; Karakoç, M; Özmen, S F; Çeçen, Y; Çoban, A; Caner, T; Bayram, E; Saito, T R; Akdoğan, T; Bozkurt, V; Kuçuk, Y; Kaya, D; Harakeh, M N

    2015-01-01

    The use of bremsstrahlung photons produced by a linac to induce photonuclear reactions is wide spread. However, using a clinical linac to produce the photons is a new concept. We aimed to induce photonuclear reactions on zinc isotopes and measure the subsequent transition energies and half-lives. For this purpose, a bremsstrahlung photon beam of 18 MeV endpoint energy produced by the Philips SLI-25 linac has been used. The subsequent decay has been measured with a well-shielded single HPGe detector. The results obtained for transition energies are in good agreement with the literature data and in many cases surpass these in accuracy. For the half-lives, we are in agreement with the literature data, but do not achieve their precision. The obtained accuracy for the transition energies show what is achievable in an experiment such as ours. We demonstrate the usefulness and benefits of employing clinical linacs for nuclear physics experiments.

  9. Vacuum simulation of the LINAC4 H- source

    CERN Document Server

    Chiara Pasquino, CP; Jacques Lettry, JL

    2012-01-01

    The 160 MeV H- Linac4 will replace the 50 MeV proton Linac2. Linac4 H- source is the new ion source. In order to study its dynamic behaviour from the vacuum point of view, the electrical network – vacuum analogy have been used. This technique allows the evaluation of the hydrogen partial pressure profile as a function of time and position, giving important information about plasma chamber and LEBT pressures. Aiming at benchmarking the following simulations, several experimental calibration campaigns are foreseen in the near future: the H- source of Linac4 requires a pulsed injection of hydrogen to reach the typically 0.1 mbar pressure mandatory for plasma formation. First preliminary results show good agreement between the experimental and the simulated profiles.

  10. A Radiation shielding study for the Fermilab Linac

    Energy Technology Data Exchange (ETDEWEB)

    Rakhno, I.; Johnstone, C.; /Fermilab

    2006-02-01

    Radiation shielding calculations are performed for the Fermilab Linac enclosure and gallery. The predicted dose rates around the access labyrinth at normal operation and a comparison to measured dose rates are presented. An accident scenario is considered as well.

  11. RLA and ERL Designs for a LINAC-RING LHEC

    CERN Document Server

    Zimmermann, F; Ciapala, E; Haug, F; Osborne, J; Schulte, D; Tomas, R; Adolphsen, C; Sun, Y; Litvinenko, V; Dainton, J; Klein, M; Chattopadhyay, S; Eide, A

    2010-01-01

    We consider three different scenarios for the recirculating electron linear accelerator (RLA) of a linac-ring type electron-proton collider based on the LHC (LHeC): i) a basic version consisting of a pulsed, 1.7 km long linac with a final beam energy of 60 GeV [“p-60”], ii) a higher luminosity configuration with a two cw linacs and energy-recovery (ERL) also at 60 GeV [“erl”], and iii) a high energy option using a pulsed linac of 3.9 km length with final energy of 140 GeV [“p-140”]. We discuss the parameters, synchrotron radiation, footprints, and the performance for the three scenarios.

  12. SCL-90的因素结构:传统因素模型与双因素模型%Factor Structure of SCL-90 in Students Sample:Traditional Factor Structure Model and Bifactor Structure

    Institute of Scientific and Technical Information of China (English)

    曾伟楠; 全鹏; 辜美惜; 李鹤展; 万崇华

    2016-01-01

    目的 比较SCL-90的单因素模型、二阶因素模型、九因素模型和双因素模型.方法 对2835名大学生为研究对象,进行SCL-90的测验,采用Mplus 7.0的WLSMV参数估计法对以上四种模型进行检验.结果 四种模型的拟合指数CFI分别是:0.906、0.928、0.930、0.940;TLI分别是0.904、0.926、0928、0.937;RMSEA分别是0.045、0.040、0.039、0.037.双因素模型82.8%的公共方差被一般因素解释,9个因素各自解释的方差比例介于0.5%至4.8%之间,一共占17.2%的方差解释比例.结论 双因素模型是SCL-90较合适的因素结构模型.

  13. An RF input coupler for a superconducting single cell cavity

    Energy Technology Data Exchange (ETDEWEB)

    Fechner, B.; Ouchi, Nobuo; Kusano, Joichi; Mizumoto, Motoharu; Mukugi, Ken [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Krawczyk, F.

    1999-03-01

    Japan Atomic Energy Research Institute proposes a high intensity proton accelerator for the Neutron Science Project. A superconducting linac is a main option for the high energy part of the accelerator. Design and development work for the superconducting accelerating cavities (resonant frequency of 600 MHz) is in progress. Superconducting cavities have an advantage of very high accelerating efficiency because RF wall loss is very small and much of the RF power fed to the cavity is consumed for the beam acceleration. On the other hand, an RF input coupler for the superconducting cavity has to be matched to the beam loading. Therefore, estimation of coupling coefficient or external quality factor (Qext) of the RF input coupler is important for the design of the couplers. In this work, Qext`s were calculated by the electromagnetic analysis code (MAFIA) and were compared with those by the measurements. A {beta} (ratio of the particle velocity to the light velocity) = 0.5 single-cell cavity with either axial coupler or side coupler was used in this work. In the experiments, a model cavity made by copper is applied. Both 2- and 3-dimensional calculations were performed in the axial coupler geometry and the results were compared. The agreements between calculated and measured values are good and this method for calculation of Qext is confirmed to be proper for the design of the RF input couplers. (author)

  14. Post-accelerator LINAC design for the VECC RIB project

    Indian Academy of Sciences (India)

    Arup Bandyopadhyay

    2002-12-01

    Variable Energy Cyclotron Centre (VECC) is presently developing an ISOL post-acclerator type of RIB facility. The scheme utilises the existing = 130 room temperature variable energy cyclotron machine as the primary accelerator for the production of RIBs and radio frequency quadrupole (RFQ) and LINAC modules for the post-acceleration. The design aspects of these postaccelerator LINAC modules will be discussed in this paper.

  15. High power operational experience with the LANSCE Linac

    Energy Technology Data Exchange (ETDEWEB)

    Rybarcyk, Lawrence J [Los Alamos National Laboratory

    2008-01-01

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

  16. Linac 1 in the process of being pulled back

    CERN Multimedia

    Photographic Service; CERN PhotoLab

    1985-01-01

    As injector to the PS Booster, Linac 1 was replaced by Linac 2 in 1980. It continued to be used for the acceleration of oxygen and sulfur ions and, from 1981 to 1996, of protons and negative hydrogen ions for LEAR. In 1984, its Cockcroft-Walton preinjector was replaced by a much smaller RFQ, which allowed it to be moved to a more convenient location.

  17. Quadrupole Law and Steering Options in the Linac4 DTL

    CERN Document Server

    Stovall, J

    2009-01-01

    The Linac4 drift-tube linac (DTL) reference design has been modified to reduce the power consumption in tank 1 by adjusting the accelerating field and phase laws. In this note we investigate three options for the transverse focusing lattice, quadrupole law, and two options for beam steering. We use acceptance, sensitivity to alignment errors and the probabiity of beam loss as figures of merit for evaluating each option.

  18. Evolution of the 400 MeV linac design

    Energy Technology Data Exchange (ETDEWEB)

    MacLachlan, J.A.

    1987-11-09

    The basic premises of the conceptual design for the linac upgrade are pursued to establish lengths, gradients, power dissipation, etc., for the 400 MeV linac and matching section. The discussion is limited to accelerating and focusing components. Wherever values depend on the choice of the accelerating structure, the disk-and-washer structure is emphasized; the results are generally relevant to the side coupled cavity choice also.

  19. Effect of cooling water on stability of NLC linac components

    Energy Technology Data Exchange (ETDEWEB)

    F. Le Pimpec et al.

    2003-02-11

    Vertical vibration of linac components (accelerating structures, girders and quadrupoles) in the NLC has been studied experimentally and analytically. Effects such as structural resonances and vibration caused by cooling water both in accelerating structures and quadrupoles have been considered. Experimental data has been compared with analytical predictions and simulations using ANSYS. A design, incorporating the proper decoupling of structure vibrations from the linac quadrupoles, is being pursued.

  20. 空中乘务员SCL-90心理量表的测量分析

    Institute of Scientific and Technical Information of China (English)

    韩立军; 岳海

    2009-01-01

    @@ 为调查研究空中乘务员的心理健康水平,笔者对东航安徽分公司240名空中乘务员进行SCL-90(symptom check list,90)症状自评量表的测试.结果显示:乘务员SCL-90测量的大部分因子与全国常模相比无显著差异,尽管"躯体化"、"焦虑"、"恐怖"这些因子的效应值稍偏离常模达到中效应水平,但是与常模比较差异没有显著性.

  1. apport alimentaire chez des patients attients la sclérose en plaque dans la region de Tlemcen

    OpenAIRE

    haddaoui, hadjer

    2015-01-01

    La sclérose en plaques (SEP) est une maladie inflammatoire et démyélinisant du système nerveux central (SNC). L'apparition de plaques démyélinisées dans le SNC est associée à un infiltrat inflammatoire principalement composé de macrophages et de lymphocytes T (LT). L'objectif de notre étude est d'évaluer l'apport alimentaire chez une population atteinte de Sclérose en plaque dans la wilaya de Tlemcen, et d'essayer de déterminer la relation entre l'apport alimentaire de fer, vit...

  2. Frontiers in Superconducting Materials

    CERN Document Server

    Narlikar, Anant V

    2005-01-01

    Frontiers in Superconducting Materials gives a state-of-the-art report of the most important topics of the current research in superconductive materials and related phenomena. It comprises 30 chapters written by renowned international experts in the field. It is of central interest to researchers and specialists in Physics and Materials Science, both in academic and industrial research, as well as advanced students. It also addresses electronic and electrical engineers. Even non-specialists interested in superconductivity might find some useful answers.

  3. High-Temperature Superconductivity

    Science.gov (United States)

    Tanaka, Shoji

    2006-12-01

    A general review on high-temperature superconductivity was made. After prehistoric view and the process of discovery were stated, the special features of high-temperature superconductors were explained from the materials side and the physical properties side. The present status on applications of high-temperature superconductors were explained on superconducting tapes, electric power cables, magnets for maglev trains, electric motors, superconducting quantum interference device (SQUID) and single flux quantum (SFQ) devices and circuits.

  4. Status and plans for Linac4 installation and commissioning

    CERN Document Server

    Vretenar, M; Arnaudon, L; Baudrenghien, P; Bellodi, G; Broere, J; Brunner, O; Comblin, J F; Coupard, J; Dimov, V A; Fuchs, J F; Funken, A; Gerigk, F; Granemann Souza, E; Hanke, K; Hansen, J; Yarmohammadi Satri, M; Kozsar, I; Lallement, J B; Lenardon, F; Lettry, J; Lombardi, A M; Maglioni, C; Midtun, O; Mikulec, B; Nisbet, D; Paoluzzi, M; Raich, U; Ramberger, S; Roncarolo, F; Rossi, C; Sanchez Alvarez, J L; Scrivens, R; Tan, J; Valerio-Lizarraga, C A; Vollaire, J; Wegner, R; Weisz, S; Zocca, F

    2014-01-01

    Linac4 is a normal conducting 160 MeV Hˉ linear accelerator presently being installed and progressively commissioned at CERN. It will replace the ageing 50 MeV Linac2 as injector of the PS Booster (PSB), increasing at the same time its brightness by a factor of two thanks to the higher injection energy. This will be the first step of a program to increase the beam brightness in the LHC injectors for the needs of the High-Luminosity LHC project. After a series of beam measurements on a dedicated test stand the 3 MeV Linac4 front-end, including ion source, RFQ and a beam chopping line, has been recommissioned at its final position in the Linac4 tunnel. Commissioning of the following section, the Drift Tube Linac, is starting. Beam commissioning will take place in steps of increasing energy, to reach the final 160 MeV in 2015. An extended beam measurement phase including testing of stripping equipment for the PSB and a year-long test run to assess and improve Linac4 reliability will take place in 2016, prior to...

  5. Beam lines from Linac 1 to PS and Booster

    CERN Multimedia

    CERN PhotoLab

    1978-01-01

    View against the direction of the proton beams. The 50 MeV Linac 1 is behind the concrete wall. Its beam emerges from the hole near the centre of the picture. A switching magnet directs the beam either to the PS (to the right in the sense of the beam; original injection line), or lets it go straight on to the Booster (originally 800 MeV, now 1.4 GeV). The huge drum in the line to the Booster is a "debuncher", driven by the 200 MHz RF of the linac. It reduces the beam's momentum spread. This was the last year of Linac 1 as provider of protons to the Booster. Linac 2, nearly completed at the time of this picture, took up trial delivery at the end of 1978, and routine delivery in 1979. The beam line from Linac 2, barely visible here, can be clearly seen on 7802260. Linac 1 had a second life as an ion accelerator.

  6. Great progress in developing 500 MHz single cell superconducting cavity in China

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Superconducting cavities have been adopted in many kinds of accelerator facilities such as synchrotron radiation light source, hard X-ray free electron laser linac, colliders and energy recovery linacs (ERL). The 500 MHz superconducting cavities will be a candidate to be installed in the high current accelerators and high current ERLs for their large beam aperture, low higher order modes impedance and high current threshold value. This paper presents great progress in the whole sequence of developing 500 MHz superconducting cavity in China. It describes the first in-house successful development of 500 MHz single cell superconducting cavity including the deep-drawing of niobium half cells, electron beam wielding of cavity, surface preparations and vertical testing. The highest accelerating gradient of the fabricated cavity #SCD-02 higher than 10 MV/m was obtained while the quality factor was better than 4×108 at 4.2 K, which has reached the world level of the same kind of cavities.

  7. Fundamentals of Superconducting Nanoelectronics

    CERN Document Server

    Sidorenko, Anatolie

    2011-01-01

    This book demonstrates how the new phenomena in superconductivity on the nanometer scale (FFLO state, triplet superconductivity, Crossed Andreev Reflection, synchronized generation etc.) serve as the basis for the invention and development of novel nanoelectronic devices and systems. It demonstrates how rather complex ideas and theoretical models, like odd-pairing, non-uniform superconducting state, pi-shift etc., adequately describe the processes in real superconducting nanostructues and novel devices based on them. The book is useful for a broad audience of readers, researchers, engineers, P

  8. Superconductive imaging surface magnetometer

    Science.gov (United States)

    Overton, Jr., William C.; van Hulsteyn, David B.; Flynn, Edward R.

    1991-01-01

    An improved pick-up coil system for use with Superconducting Quantum Interference Device gradiometers and magnetometers involving the use of superconducting plates near conventional pick-up coil arrangements to provide imaging of nearby dipole sources and to deflect environmental magnetic noise away from the pick-up coils. This allows the practice of gradiometry and magnetometry in magnetically unshielded environments. One embodiment uses a hemispherically shaped superconducting plate with interior pick-up coils, allowing brain wave measurements to be made on human patients. another embodiment using flat superconducting plates could be used in non-destructive evaluation of materials.

  9. Superconducting optical modulator

    Science.gov (United States)

    Bunt, Patricia S.; Ference, Thomas G.; Puzey, Kenneth A.; Tanner, David B.; Tache, Nacira; Varhue, Walter J.

    2000-12-01

    An optical modulator based on the physical properties of high temperature superconductors has been fabricated and tested. The modulator was constructed form a film of Yttrium Barium Copper Oxide (YBCO) grown on undoped silicon with a buffer layer of Yttria Stabilized Zirconia. Standard lithographic procedures were used to pattern the superconducting film into a micro bridge. Optical modulation was achieved by passing IR light through the composite structure normal to the micro bridge and switching the superconducting film in the bridge region between the superconducting and non-superconducting states. In the superconducting state, IR light reflects from the superconducting film surface. When a critical current is passed through the micro bridge, it causes the film in this region to switch to the non-superconducting state allowing IR light to pass through it. Superconducting materials have the potential to switch between these two states at speeds up to 1 picosecond using electrical current. Presently, fiber optic transmission capacity is limited by the rate at which optical data can be modulated. The superconducting modulator, when combined with other components, may have the potential to increase the transmission capacity of fiber optic lines.

  10. Basic Study of Superconductive Actuator

    OpenAIRE

    涌井, 和也; 荻原, 宏康

    2000-01-01

    There are two kinds of electromagnetic propulsion ships : a superconductive electromagnetic propulsion ship and a superconductive electricity propulsion ship. A superconductive electromagnetic propulsion ship uses the electromagnetic force (Lorenz force) by the interaction between a magnetic field and a electric current. On the other hand, a superconductive electricity propulsion ship uses screws driven by a superconductive motor. A superconductive propulsion ship technique has the merits of ...

  11. A novel electron gun for inline MRI-linac configurations

    Energy Technology Data Exchange (ETDEWEB)

    Constantin, Dragoş E., E-mail: dragos.constantin@varian.com; Fahrig, Rebecca [Department of Radiology, Stanford University, Stanford, California 94305 (United States); Holloway, Lois [Liverpool and Macarthur Cancer Therapy Centres, The University of Sydney, NSW 2006 (Australia); Keall, Paul J. [Radiation Physics Laboratory, The University of Sydney, NSW 2006 (Australia)

    2014-02-15

    Purpose: This work introduces a new electron gun geometry capable of robust functioning in the presence of a high strength external magnetic field for axisymmetric magnetic resonance imaging (MRI)-linac configurations. This allows an inline MRI-linac to operate without the need to isolate the linear accelerator (linac) using a magnetic shield. This MRI-linac integration approach not only leaves the magnet homogeneity unchanged but also provides the linac flexibility to move along the magnet axis of symmetry if the source to target distance needs to be adjusted. Methods: Simple electron gun geometry modifications of a Varian 600C electron gun are considered and solved in the presence of an external magnetic field in order to determine a set of design principles for the new geometry. Based on these results, a new gun geometry is proposed and optimized in the fringe field of a 0.5 T open bore MRI magnet (GE Signa SP). A computer model for the 6 MeV Varian 600C linac is used to determine the capture efficiency of the new electron gun-linac system in the presence of the fringe field of the same MRI scanner. The behavior of the new electron gun plus the linac system is also studied in the fringe fields of two other magnets, a 1.0 T prototype open bore magnet and a 1.5 T GE Conquest scanner. Results: Simple geometrical modifications of the original electron gun geometry do not provide feasible solutions. However, these tests show that a smaller transverse cathode diameter with a flat surface and a slightly larger anode diameter could alleviate the current loss due to beam interactions with the anode in the presence of magnetic fields. Based on these findings, an initial geometry resembling a parallel plate capacitor with a hole in the anode is proposed. The optimization procedure finds a cathode-anode distance of 5 mm, a focusing electrode angle of 5°, and an anode drift tube length of 17.1 mm. Also, the linac can be displaced with ±15 cm along the axis of the 0.5 T

  12. First Demonstration of Electron Beam Generation and Characterization with an All Superconducting Radio-frequency (SRF) Photoinjector

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-09-01

    In preparation for a high brightness, high average current electron source for the energy-recovery linac BERLinPro an all superconducting radio-frequency photoinjector is now in operation at Helmholtz-Zentrum Berlin. The aim of this experiment is beam demonstration with a high brightness electron source able to generate sub-ps pulse length electron bunches from a superconducting (SC) cathode film made of Pb coated on the backwall of a Nb SRF cavity. This paper describes the setup of the experiment and first results from beam measurements.

  13. Accelerator Science and Technology in Canada -- From the Microtron to TRIUMF, Superconducting Cyclotrons and the Canadian Light Source

    Science.gov (United States)

    Craddock, M. K.; Laxdal, R. E.

    As elsewhere, accelerators in Canada have evolved from modest beginnings to major facilities such as TRIUMF (currently with the highest-power driver for rare isotope beam production) and the third generation Canadian Light Source. Highlights along the way include construction of the first microtron, the first racetrack microtron and the first superconducting cyclotron (to which list might have been added the first pulse stretcher ring, had it been funded sooner). This article will summarize the history of accelerators in Canada, documenting both the successes and the near-misses. Besides the research accelerators, a thriving commercial sector has developed, manufacturing small cyclotrons and linacs, beam line components and superconducting rf cavities.

  14. Accelerator Science and Technology in Canada — From the Microtron to TRIUMF, Superconducting Cyclotrons and the Canadian Light Source

    Science.gov (United States)

    Craddock, M. K.; Laxdal, R. E.

    As elsewhere, accelerators in Canada have evolved from modest beginnings to major facilities such as TRIUMF (currently with the highest-power driver for rare isotope beam production) and the third generation Canadian Light Source. Highlights along the way include construction of the first microtron, the first racetrack microtron and the first superconducting cyclotron (to which list might have been added the first pulse stretcher ring, had it been funded sooner). This article will summarize the history of accelerators in Canada, documenting both the successes and the near-misses. Besides the research accelerators, a thriving commercial sector has developed, manufacturing small cyclotrons and linacs, beam line components and superconducting rf cavities.

  15. 中国版SCL-90的效度研究%Study on the validity of the Symptom Check-List-90 of Chinese version

    Institute of Scientific and Technical Information of China (English)

    冯正直; 张大均

    2001-01-01

    目的 检测中国版症状自评量表(The Symptom Check-List-90,SCL-90)的效度。方法 624名正常人和268名心理门诊病人用SCL-90测量。结果 (1)SCL-90的各因子内部一致性较好,α系数在0.78~0.90之间;(2)判别函数分析发现SCL-90能很好区分病人和正常人,正判率为80.6%;(3)因素分析表现出单个因素能代表SCL-90大多数的因子;(4)SCL-90的九个因子之间存在高的相关,相关系数范围在0.39~0.79之间。结论 (1)SCL-90作为精神症状测验和研究量表是可接受的;(2)SCL-90不能作为不同精神症状区分和诊断量表;(3)SCL-90不是一个多维度的量表。%Objective To investigate the validity of the Chinese version of the Symptom Check-List-90 (the SCL-90) in Chinese population. Methods A total of 624 normal person and 268 out patients were examined with the SCL-90. Results (1)The internal consistency of the original subscales was found to be good and Cronbach's coefficient alpha ranged from 0.78 to 0.90; (2)Discrimination function analysis based on the 9 original subscales showed that the power of the SCL-90 in discriminating the patients and the community was good with a corrective rate of 80.6%; (3)Factor analysis on the items of the questionnaire yielded a very strong un-rotated first factor which could represent other factors; (4)High inter-correlations were found between the 9 original subscales of the SCL-90 with a correlation coefficient ranging from 0.39 to 0.79. Conclusion (1) The SCL-90 is acceptable as a research setting and psychiatric screening inventory; (2) The SCL-90 does not have potential as an inventory to distinguish different diagnostic groups; (3) The SCL-90 is not a multidimensional inventory.

  16. Linac4 chopper line commissioning strategy

    CERN Document Server

    Bellodi, G; Lombardi, A M; Posocco, P A; Sargsyan, E

    2010-01-01

    The report outlines the strategy for beam-based commissioning of the Linac4 3 MeV chopper line as currently scheduled to start in the second half of 2011 in the Test Stand Area. A dedicated temporary diagnostics test bench will complement the measurement devices foreseen for permanent installation in the chopper line. A commissioning procedure is set out as a series of consecutive phases, each one supposed to meet a well- defined milestone in the path to fully characterise the beam-line. Specific set-ups for each stage are defined in terms of beam characteristics, machine settings and diagnostics used. Operational guidelines are given and expected results at the relative points of measurements are shown for simulated scenarios (on the basis of multi-particle tracking studies carried out with the codes PATH and TRACEWin). These are then interpreted in the light of the resolution limits of the available diagnostics instruments to assess the precision reach on individual measurements and the feasibility of techn...

  17. Linac4 chopper line commissioning strategy

    CERN Document Server

    Bellodi, G; Lombardi, AM; Posocco, PA; Sargsyan, E

    2010-01-01

    The report outlines the strategy for beam-based commissioning of the Linac4 3 MeV chopper line as currently scheduled to start in the second half of 2011 in the Test Stand Area. A dedicated temporary diagnostics test bench will complement the measurement devices foreseen for permanent installation in the chopper line. A commissioning procedure is set out as a series of consecutive phases, each one supposed to meet a well- defined milestone in the path to fully characterise the beam-line. Specific set-ups for each stage are defined in terms of beam characteristics, machine settings and diagnostics used. Operational guidelines are given and expected results at the relative points of measurements are shown for simulated scenarios (on the basis of multi-particle tracking studies carried out with the codes PATH and TRACEWin). These are then interpreted in the light of the resolution limits of the available diagnostics instruments to assess the precision reach on individual measurements and the feasibility of techn...

  18. Setup verification in linac-based radiosurgery.

    Science.gov (United States)

    Falco, T; Lachaine, M; Poffenbarger, B; Podgorsak, E B; Fallone, B G

    1999-09-01

    A semi-automatic technique for the direct setup alignment of radiosurgical circular fields from an isocentric linac to treatment room laser cross-hairs is described. Alignment is achieved by acquiring images of the treatment room positioning laser cross-hairs superimposed on the radiosurgical circular field image. An alignment algorithm calculates the center of the radiosurgical field image as well as the intersection of the laser cross-hairs. This determines any alignment deviations and the information is then used to translate the radiosurgical collimator to its correct aligned position. Two detectors, each being sensitive to the lasers and ionizing radiation, were used to acquire the radiation/laser images. The first detector consists of a 0.3-mm-thick layer of photoconducting a-Se deposited on a 1.5-mm-thick copper plate and the second is film. The algorithm and detector system can detect deviations with a precision of approximately 0.04 mm. A device with gyroscopic degrees of freedom was built in order to firmly hold the detector at any orientation perpendicular to the radiosurgical beam axis. This device was used in conjunction with our alignment algorithm to quantify the isocentric sphere relative to the treatment room lasers over all gantry and couch angles used in dynamic stereotactic radiosurgery.

  19. Frequency Control Loop for Drift Tube Linac

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Hyeok Jung; Kim, Han Sung; Seol, Kyung Tae; Song, Young Gi; Jang, Ji Ho; Cho, Yong Sub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    In this paper, the preparation of the frequency tracking of the RCCS by connecting the RCCS to low level RF (LLRF) system is described. KOMAC 100-MeV proton accelerator is under operation and supply beam to users. We are developing frequency control function in the LLRF system to control the RCCS in frequency control mode. After the test in the test bench, the system will be applied to the 100-MeV DTL RCCS in order to supply better quality beam to users. A 100-MeV proton accelerator has been developed and the operation and beam service started at Korea Multipurpose Accelerator Complex (KOMAC) in June 2013. The accelerator consists of a 50-keV proton injector, a 3-MeV radio frequency quadrupole (RFQ) and 100-MeV drift tube linac (DTL). The resonance frequency of the DTL tanks are controlled by using the resonance frequency control cooling system (RCCS), which are installed at every each tank. Until now, the RCCS has been operating in constant temperature mode which means that the frequency was measured with respect to the RCCS supply temperature before the RF operation, and then the RCCS operates with that temperature throughout the whole operation. The constant temperature operation is simple but the RF stability is not good because many perturbations such as RCCS supply temperature error can cause a frequency change. To stabilize the system better, it is necessary to operate the RCCS in frequency tracking mode.

  20. Industrial RF Linac Experiences and Laboratory Interactions

    CERN Document Server

    Peiniger, M

    2004-01-01

    Since more than two decades ACCEL Instruments GmbH at Bergisch Gladbach (formerly Siemens/Interatom) is supplying the worldwide accelerator labs with key components like rf cavities and power couplers, s.c. magnets, insertion devices, vacuum chambers and x-ray beamline equipment. Starting with the design and production of turn key SRF accelerating modules in the late 80th, meanwhile ACCEL is engineering, manufacturing, on site commissioning and servicing complete accelerators with guaranteed beam performance. Today, with a staff of more than 100 physicists and engineers and about the same number of manufacturing specialists in our dedicated production facilities, ACCEL's know how and sales volume in this field has accumulated to more than 2000 man years and several hundred Mio €, respectively. Basis of our steady development is a cooperative partnership with the world leading research labs in the respective fields. As an example, for the supply of a turn key 100 MeV injector linac for the Swiss Ligh...

  1. Delta undulator for Cornell energy recovery linac

    Directory of Open Access Journals (Sweden)

    Alexander B. Temnykh

    2008-12-01

    Full Text Available In anticipation of a new era of synchrotron radiation sources based on energy recovery linac techniques, we designed, built, and tested a short undulator magnet prototype whose features make optimum use of the unique conditions expected in these facilities. The prototype has pure permanent magnet (PPM structure with 24 mm period, 5 mm diameter round gap, and is 30 cm long. In comparison with conventional undulator magnets it has the following: (i full x-ray polarization control.—It may generate varying linear polarized as well as left and right circular polarized x rays with photon flux much higher than existing Apple-II–type devices. (ii 40% stronger magnetic field in linear and approximately 2 times stronger in circular polarization modes. This advantage translates into higher x-ray flux. (iii Compactness.—The prototype can be enclosed in a ∼20  cm diameter cylindrical vacuum vessel. These advantages were achieved through a number of unconventional approaches. Among them is control of the magnetic field strength via longitudinal motion of the magnet arrays. The moving mechanism is also used for x-ray polarization control. The compactness is achieved using a recently developed permanent magnet soldering technique for fastening PM blocks. We call this device a “Delta” undulator after the shape of its PM blocks. The presented article describes the design study, various aspects of the construction, and presents some test results.

  2. Emittance and Phase Space Tomography for the Fermilab Linac

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, F.G.G.; Johnstone, C.; Kobilarcik, T.; Koizumi, G.M.; Moore, C.D.; /Fermilab; Newhart, D.L.; /Fermilab

    2012-05-01

    The Fermilab Linac delivers a variable intensity, 400-MeV beam to the MuCool Test Area experimental hall via a beam line specifically designed to facilitate measurements of the Linac beam emittance and properties. A 10 m, dispersion-free and magnet-free straight utilizes an upstream quadrupole focusing triplet in combination with the necessary in-straight beam diagnostics to fully characterize the transverse beam properties. Since the Linac does not produce a strictly elliptical phase space, tomography must be performed on the profile data to retrieve the actual particle distribution in phase space. This is achieved by rotating the phase space distribution using different waist focusing conditions of the upstream triplet and performing a deconvolution of the profile data. Preliminary measurements using this diagnostic section are reported here. These data represent a first-pass measurement of the Linac emittance based on various techniques. It is clear that the most accurate representation of the emittance is given by the 3-profile approach. Future work will entail minimizing the beam spot size on MW5 to test and possibly improve the accuracy of the 2-profile approach. The 95% emittance is {approx} 18{pi} in the vertical and {approx} 13{pi} in the horizontal, which is especially larger than anticipated - 8-10{pi} was expected. One possible explanation is that the entire Linac pulse is extracted into the MTA beamline and during the first few microseconds, the feed forward and RF regulation are not stable. This may result in a larger net emittance observed versus beam injected into Booster, where the leading part of the Linac beam pulse is chopped. Future studies will clearly entail a measurement of the emittance vs. pulse length. One additional concern is that the Linac phase space is most likely aperture-defined and non-elliptical in nature. A non-elliptical phase-space determination would require a more elaborate analysis and provide another explanation of the

  3. Graphene: Carbon's superconducting footprint

    Science.gov (United States)

    Vafek, Oskar

    2012-02-01

    Graphene exhibits many extraordinary properties, but superconductivity isn't one of them. Two theoretical studies suggest that by decorating the surface of graphene with the right species of dopant atoms, or by using ionic liquid gating, superconductivity could yet be induced.

  4. Superconducting cavities for LEP

    CERN Multimedia

    1983-01-01

    Above: a 350 MHz superconducting accelerating cavity in niobium of the type envisaged for accelerating electrons and positrons in later phases of LEP. Below: a small 1 GHz cavity used for investigating the surface problems of superconducting niobium. Albert Insomby stays on the right. See Annual Report 1983 p. 51.

  5. Academic training: Applied superconductivity

    CERN Multimedia

    2007-01-01

    LECTURE SERIES 17, 18, 19 January from 11.00 to 12.00 hrs Council Room, Bldg 503 Applied Superconductivity : Theory, superconducting Materials and applications E. PALMIERI/INFN, Padova, Italy When hearing about persistent currents recirculating for several years in a superconducting loop without any appreciable decay, one realizes that we are dealing with a phenomenon which in nature is the closest known to the perpetual motion. Zero resistivity and perfect diamagnetism in Mercury at 4.2 K, the breakthrough during 75 years of several hundreds of superconducting materials, the revolution of the "liquid Nitrogen superconductivity"; the discovery of still a binary compound becoming superconducting at 40 K and the subsequent re-exploration of the already known superconducting materials: Nature discloses drop by drop its intimate secrets and nobody can exclude that the last final surprise must still come. After an overview of phenomenology and basic theory of superconductivity, the lectures for this a...

  6. Study of injection of 50 MeV proton beam from Linac2 and from Linac4 into the PS Booster

    CERN Document Server

    Raginel, V; Carli, C; Benedetto, E

    2012-01-01

    The present note indicates the brightness that can be expected for a LHC beam (LHC-25ns) in the PS Booster after a multi-turn injection of 50 MeV protons from Linac4. The motivation for this study has been to know if Linac4 could be a reasonable backup for Linac2 in case of breakdown. The results of this study are derived from simulations of the current PS Booster multi-turn injection with the ORBIT code. First the PS Booster injection model is tested with the reference Linac2 beam injection parameters, and then injection of Linac4 50 MeV protons is simulated and optimized for the highest brightness according to the required LHC emittance. A comparison of the multi-turn injection of Linac2 and Linac4 50 MeV proton beam is presented in the last section.

  7. TaSCL14, a novel wheat (Triticum aestivum L.) GRAS gene, regulates plant growth, photosynthesis, tolerance to photooxidative stress, and senescence.

    Science.gov (United States)

    Chen, Kunmei; Li, Hongwei; Chen, Yaofeng; Zheng, Qi; Li, Bin; Li, Zhensheng

    2015-01-20

    Rates of photosynthesis, tolerance to photooxidative stress, and senescence are all important physiological factors that affect plant development and thus agricultural productivity. GRAS proteins play essential roles in plant growth and development as well as in plant responses to biotic and abiotic stresses. So far few GRAS genes in wheat (Triticum aestivum L.) have been characterized. A previous transcriptome analysis indicated that the expression of a GRAS gene (TaSCL14) was induced by high-light stress in Xiaoyan 54 (XY54), a common wheat cultivar with strong tolerance to high-light stress. In this study, TaSCL14 gene was isolated from XY54 and mapped on chromosome 4A. TaSCL14 was expressed in various wheat organs, with high levels in stems and roots. Our results confirmed that TaSCL14 expression was indeed responsive to high-light stress. Barley stripe mosaic virus (BSMV)-based virus-induced gene silencing (VIGS) of TaSCL14 in wheat was performed to help characterize its potential functions. Silencing of TaSCL14 resulted in inhibited plant growth, decreased photosynthetic capacity, and reduced tolerance to photooxidative stress. In addition, silencing of TaSCL14 in wheat promoted leaf senescence induced by darkness. These results suggest that TaSCL14 may act as a multifunctional regulator involved in plant growth, photosynthesis, tolerance to photooxidative stress, and senescence. Copyright © 2014 Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, and Genetics Society of China. Published by Elsevier Ltd. All rights reserved.

  8. LUX - a recirculating linac-based facility for ultrafast X-ray science

    Energy Technology Data Exchange (ETDEWEB)

    Corlett, J.N.; Barletta, W.A.; DeSantis, S.; Doolittle, L.; Fawley, W.M.; Heimann, P.; Leone, S.; Lidia, S.; Li, D.; Penn, G.; Ratti, A.; Reinsch, M.; Schoenlein, R.; Staples, J.; Stover, G.; Virostek, S.; Wan, W.; Wells, R.; Wilcox, R.; Wolski, A.; Wurtele, J.; Zholents, A.

    2004-06-29

    We present recent developments in design concepts for LUX - a source of ultra-short synchrotron radiation pulses based on a recirculating superconducting linac. The source produces high-flux x-ray pulses with duration of 100 fs or less at a 10 kHz repetition rate, optimized for the study of ultra-fast dynamics across many fields of science [1]. Cascaded harmonic generation in free-electron lasers (FEL's) produces coherent radiation in the VUV-soft x-ray regime, and a specialized technique is used to compress spontaneous emission for ultra-short-pulse photon production in the 1-10 keV range. High-brightness electron bunches of 2-3 mm-mrad emittance at 1 nC charge in 30 ps duration are produced in an rf photocathode gun and compressed to 3 ps duration following an injector linac, and recirculated three times through a 1 GeV main linac. In each return path, independently tunable harmonic cascades are inserted to produce seeded FEL radiation in selected photon energy ranges from approximately 20 eV with a single stage of harmonic generation, to 1 keV with a four-stage cascade. The lattice is designed to minimize emittance growth from effects such as coherent synchrotron radiation (CSR), and resistive wall wakefields. Timing jitter between pump lasers and x-ray pulses is minimized by use of a stable optical master oscillator, distributing timing signals over actively stabilized fiber-optic, phase-locking all lasers to the master oscillator, and generating all rf signals from the master oscillator. We describe technical developments including techniques for minimizing power dissipation in a high repetition rate rf photocathode gun, beam dynamics in two injector configurations, independently tunable beamlines for VUV and soft x-ray production by cascaded harmonic generation, a fast kicker design, timing systems for providing synchronization between experimental pump lasers and the x-ray pulse, and beamline design for maintaining nm-scale density modulation.

  9. Production design of the drift tube Linac for the CERN Linac4

    CERN Document Server

    Ramberger, S; Cuvet, Y; Dallocchio, A; De Michele, G; Gerigk, F; Giguet, J M; Lallement, J B; Lombardi, A M; Sargsyan, E; Vretenar, M

    2010-01-01

    The design of the Drift Tube Linac (DTL) for the new linear accelerator Linac4 at CERN has been made ready for production: H--ion beams of up to 40 mA average pulse current are to be accelerated from 3 to 50 MeV by three RF cavities operating at 352.2MHz and at duty cycles of up to 10%. In order to provide a margin for longitudinal matching from the chopper line, the longitudinal acceptance has been increased. The synchronous phase starts at -35 deg in Tank1 and ramps linearly to -24 deg over the tank while it went from -30 to -20 deg in the previous design. The accelerating gradient has been reduced to 3.1MV/m in Tank1 and increased to 3.3 MV/m in Tank2 and Tank3 for a better distribution of RF power between tanks that is compatible with a mechanical design. To make the transverse acceptance less sensitive to alignment and gradient errors, the focusing scheme is now FFDD over all 3 tanks. Design features that were demonstrated in earlier reports have been improved for series production. Results of high power...

  10. Superconductivity in carbon nanomaterials

    Science.gov (United States)

    Dlugon, Katarzyna

    The purpose of this thesis is to explain the phenomenon of superconductivity in carbon nanomaterials such as graphene, fullerenes and carbon nanotubes. In the introductory chapter, there is a description of superconductivity and how it occurs at critical temperature (Tc) that is characteristic and different to every superconducting material. The discovery of superconductivity in mercury in 1911 by Dutch physicist Heike Kamerlingh Onnes is also mentioned. Different types of superconductors, type I and type II, low and high temperatures superconductors, as well as the BCS theory that was developed in 1957 by Bardeen, Cooper, and Schrieffer, are also described in detail. The BCS theory explains how Cooper's pairs are formed and how they are responsible for the superconducting properties of many materials. The following chapters explain superconductivity in doped fullerenes, graphene and carbon nanotubes, respectively. There is a thorough explanation followed by many examples of different types of carbon nanomaterials in which small changes in chemical structure cause significant changes in superconducting properties. The goal of this research was not only to take into consideration well known carbon based superconductors but also to search for the newest available materials such as the fullerene nanowhiskers discovered quite recently. There is also a presentation of fairly new ideas about inducing superconductivity in a monolayer of graphene which is more challenging than inducing superconductivity in graphite by simply intercalating metal atoms between its graphene sheets. An effort has been taken to look for any available information about carbon nanomaterials that have the potential to superconduct at room temperature, mainly because discovery of such materials would be a real revolution in the modern world, although no such materials have been discovered yet.

  11. Final Commissioning of the Superconducting Heavy Ion Linear Accelerator at IUAC, Delhi

    Science.gov (United States)

    Datta, Tripti Sekhar; Choudhury, Anup; Chacko, Jacob; Kar, Soumen; Antony, Joby; Babu, Suresh; Kumar, Manoj; Mathuria, D. S.; Sahu, Santosh; Kanjilal, Dinakar

    The superconducting linac as a booster of the 15UD Pelletron accelerator was partly commissioned with one linac module housing eight quarter wave bulk niobium cavities along with the superbuncher and rebuncher cryomodules. Subsequently two more linac cryomodules were added to have in total 24 cavities for acceleration. In addition, a new Linde helium refrigerator of capacity 750 W @ 4.2 K was installed in parallel to the earlier CCI refrigerator. The new refrigerator was integrated with the earlier cryogenics network system through a specially designed liquid helium distribution line without any valve box. The cooling philosophy with this new system is modified to have a faster cool down rate in the critical zone (150 - 70 K) to avoid Q disease. The helium gas pressure fluctuation in the cavities is reduced significantly to have stable RF locking. The full linac is being operated and beams with higher energy are being delivered to the users. The present paper will highlight the performance of the new cryogenic system with respect to cool down rate, and helium pressure fluctuation.

  12. Emittance reconstruction technique for the Linac4 high energy commissioning

    CERN Document Server

    Lallement, JB; Posocco, PA

    2012-01-01

    Linac4 is a new 160 MeV linear accelerator for negative Hydrogen ions (H-) presently under construction which will replace the 50 MeV proton Linac2 as injector for the CERN proton accelerator complex. Linac4 is 80 meters long and comprises a Low Energy Beam Transport line, a 3 MeV RFQ, a MEBT, a 50 MeV DTL, a 100 MeV CCDTL and a PIMS up to 160 MeV. The commissioning of the Linac is scheduled to start in 2013. It will be divided into several steps corresponding to the commissioning of the different accelerating structures. A temporary measurement bench will be dedicated to the high energy commissioning from 30 to 100 MeV (DTL tanks 2 and 3, and CCDTL). The commissioning of the PIMS will be done using the permanent equipment installed in between the end of the Linac and the main dump. This note describes the technique we will use for reconstructing the transverse emittances and the expected results.

  13. CERN Linac4 - The Space Charge Challenge Design and Commission

    CERN Document Server

    Hein, Lutz Matthias; Holzer, Bernhard

    In the first phase of the upgrade program of the CERN accelerator complex the proton injector Linac2 will be replaced by a new, normal-conducting $H^-$ ion Linac, Linac4, allowing a significant increase of the proton flux intensity along the downstream accelerator complex. In the design of Linac4 three beam transport sections are implemented to match the beam between the different accelerator elements and to model the longitudinal pulse structure. These three beam transport sections, which are the most critical locations in terms of beam quality preservation, are in the focus of this thesis. During the work of this thesis the low energy beam transport (LEBT), which is required to match the source beam to the radiofrequency quadrupole (RFQ), has been commissioned and its beam dynamics re-constructed. The measurement campaign used to re-construct the LEBT beam dynamics was performed with the aim to prepare the RFQ commissioning and to maximise the LEBT performance. Downstream of the Linac4 accelerator the beam...

  14. Mechanical Engineering of the Linac for the Spallation Neutron Source

    Energy Technology Data Exchange (ETDEWEB)

    Bultman, N.K.; Chen, Z.; Collier, M.; Erickson, J.L.; Guthrie, A.; Hunter, W.T.; Ilg, T.; Meyer, R.K.; Snodgrass, N.L.

    1999-03-29

    The linac for the Spallation Neutron Source (SNS) Project will accelerate an average current of 1 mA of H{sup {minus}} ions from 20 MeV to 1GeV for injection into an accumulator ring. The linac will be an intense source of H{sup {minus}} ions and as such requires advanced design techniques to meet project technical goals as well as to minimize costs. The DTL, CCDTL and CCL are 466m long and operate at 805 MHz with a maximum H{sup {minus}} input current of 28 mA and 7% rf duty factor. The Drift Tube Linac is a copper-plated steel structure using permanent magnetic quadrupoles. The Coupled-Cavity portions are brazed copper structures and use electromagnetic quads. RF losses in the copper are 80 MW, with total rf power supplied by 52 klystrons. Additionally, the linac is to be upgraded to the 2- and 4-MW beam power levels with no increase in duty factor. The authors give an overview of the linac mechanical engineering effort and discuss the special challenges and status of the effort.

  15. Superconductivity in aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Kubozono, Yoshihiro, E-mail: kubozono@cc.okayama-u.ac.jp [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Research Center of New Functional Materials for Energy Production, Storage and Transport, Okayama University, Okayama 700-8530 (Japan); Japan Science and Technology Agency, ACT-C, Kawaguchi 332-0012 (Japan); Goto, Hidenori; Jabuchi, Taihei [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Yokoya, Takayoshi [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Research Center of New Functional Materials for Energy Production, Storage and Transport, Okayama University, Okayama 700-8530 (Japan); Kambe, Takashi [Department of Physics, Okayama University, Okayama 700-8530 (Japan); Sakai, Yusuke; Izumi, Masanari; Zheng, Lu; Hamao, Shino; Nguyen, Huyen L.T. [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Sakata, Masafumi; Kagayama, Tomoko; Shimizu, Katsuya [Center of Science and Technology under Extreme Conditions, Osaka University, Osaka 560-8531 (Japan)

    2015-07-15

    Highlights: • Aromatic superconductor is one of core research subjects in superconductivity. Superconductivity is observed in certain metal-doped aromatic hydrocarbons. Some serious problems to be solved exist for future advancement of the research. This article shows the present status of aromatic superconductors. - Abstract: ‘Aromatic hydrocarbon’ implies an organic molecule that satisfies the (4n + 2) π-electron rule and consists of benzene rings. Doping solid aromatic hydrocarbons with metals provides the superconductivity. The first discovery of such superconductivity was made for K-doped picene (K{sub x}picene, five benzene rings). Its superconducting transition temperatures (T{sub c}’s) were 7 and 18 K. Recently, we found a new superconducting K{sub x}picene phase with a T{sub c} as high as 14 K, so we now know that K{sub x}picene possesses multiple superconducting phases. Besides K{sub x}picene, we discovered new superconductors such as Rb{sub x}picene and Ca{sub x}picene. A most serious problem is that the shielding fraction is ⩽15% for K{sub x}picene and Rb{sub x}picene, and it is often ∼1% for other superconductors. Such low shielding fractions have made it difficult to determine the crystal structures of superconducting phases. Nevertheless, many research groups have expended a great deal of effort to make high quality hydrocarbon superconductors in the five years since the discovery of hydrocarbon superconductivity. At the present stage, superconductivity is observed in certain metal-doped aromatic hydrocarbons (picene, phenanthrene and dibenzopentacene), but the shielding fraction remains stubbornly low. The highest priority research area is to prepare aromatic superconductors with a high superconducting volume-fraction. Despite these difficulties, aromatic superconductivity is still a core research target and presents interesting and potentially breakthrough challenges, such as the positive pressure dependence of T{sub c} that is clearly

  16. The superconducting spin valve and triplet superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Garifullin, I.A., E-mail: ilgiz_garifullin@yahoo.com [Zavoisky Physical-Technical Institute, Kazan Scientific Center of Russian Academy of Sciences, 420029 Kazan (Russian Federation); Leksin, P.V.; Garif' yanov, N.N.; Kamashev, A.A. [Zavoisky Physical-Technical Institute, Kazan Scientific Center of Russian Academy of Sciences, 420029 Kazan (Russian Federation); Fominov, Ya.V. [L. D. Landau Institute for Theoretical Physics RAS, 119334 Moscow (Russian Federation); Moscow Institute of Physics and Technology, 141700 Dolgoprudny (Russian Federation); Schumann, J.; Krupskaya, Y.; Kataev, V.; Schmidt, O.G. [Leibniz Institute for Solid State and Materials Research IFW Dresden, D-01171 Dresden (Germany); Büchner, B. [Leibniz Institute for Solid State and Materials Research IFW Dresden, D-01171 Dresden (Germany); Institut für Festkörperphysik, Technische Universität Dresden, D-01062 Dresden (Germany)

    2015-01-01

    A review of our recent results on the spin valve effect is presented. We have used a theoretically proposed spin switch design F1/F2/S comprising a ferromagnetic bilayer (F1/F2) as a ferromagnetic component, and an ordinary superconductor (S) as the second interface component. Based on it we have prepared and studied in detail a set of multilayers CoO{sub x}/Fe1/Cu/Fe2/S (S=In or Pb). In these heterostructures we have realized for the first time a full spin switch effect for the superconducting current, have observed its sign-changing oscillating behavior as a function of the Fe2-layer thickness and finally have obtained direct evidence for the long-range triplet superconductivity arising due to noncollinearity of the magnetizations of the Fe1 and Fe2 layers. - Highlights: • We studied a spin switch design F1/F2/S. • We prepared a set of multilayers CoOx/Fe1/Cu/Fe2/S (S=In or Pb). • The full spin switch effect for the superconducting current was realized. • We observed its oscillating behavior as a function of the Fe2-layer thickness. • We obtained direct evidence for the long-range triplet superconductivity.

  17. Antibodies to fibrillarin, PM-Scl and RNA polymerase III detected by ELISA assays in patients with systemic sclerosis.

    Science.gov (United States)

    Villalta, Danilo; Morozzi, Gabriella; Tampoia, Marilina; Alpini, Claudia; Brusca, Ignazio; Salgarolo, Valeria; Papisch, Wolfgang; Bizzaro, Nicola

    2010-05-02

    Anti-fibrillarin (AFA), anti-RNA polymerase (anti-RNAP), and anti-PM-Scl autoantibodies are useful markers for the diagnosis of systemic sclerosis (SSc) in patients who are anti-centromere- (ACA) or anti-topoisomerase I (anti-topo I)-negative, but, until recently, the only specific method for their identification was the radio-immunoprecipitation assay. The aim of this study was to evaluate the clinical accuracy of the new enzyme-linked immunosorbent assays (ELISA) developed by Phadia for their detection. Sera of 50 ACA and anti-topo I-negative SSc patients, and, as control group, sera of 122 patients (42 with SSc, ACA or anti-topo I-positive, 40 with systemic lupus erythematosus and 40 with rheumatoid arthritis) were studied. Using the cutoff proposed by the manufacturer (10 AU/mL), sensitivity and specificity were: for AFA, 22% and 92.6%; for anti-RNAP, 16% and 97.5%; and for anti-PM-Scl, 8% and 98.8%, respectively. Using a cutoff corresponding to 98.8% specificity for all three antibodies, sensitivity was 10%, 14% and 8%, respectively. The combined use of these three antibody assays enabled identification of 32% of ACA- and anti-topo I-negative SSc patients. These new ELISA methods for AFA, anti-RNAP III and anti-PM-Scl detection have good diagnostic specificity, and may help identify a subset of SSc patients ACA and anti-topo I-negative. Copyright 2010 Elsevier B.V. All rights reserved.

  18. Finite Element Thermal Study of the Linac4 Plasma Generatora

    CERN Document Server

    Faircloth, D; Kuchler, D; Lettry, L; Scrivens, R; CERN. Geneva. BE Department

    2010-01-01

    The temperature distribution and heat flow at equilibrium of the plasma generator of the RF-powered non-cesiated Linac4 H- ion source have been studied with a finite element model. It is shown that the equilibrium temperatures obtained in the Linac4 nominal operation mode (100 kW RF power, 2 Hz, 0.4 ms pulse duration) are within material specifications except for the magnet cage, where a redesign may be necessary. To assess the upgrade of the Linac4 source for operation in the high-power operation mode of SPL, an extrapolation of the heat load towards 100 kW RF power, 50 Hz repetition rate and 0.4 ms pulse duration has been performed. The results indicate that a significant improvement of the source cooling is required to allow for operation in HP-SPL.

  19. A hot-spare injector for the APS linac.

    Energy Technology Data Exchange (ETDEWEB)

    Lewellen, J. W.

    1999-04-13

    Last year a second-generation SSRL-type thermionic cathode rf gun was installed in the Advanced Photon Source (APS) linac. This gun (referred to as ''gun2'') has been successfully commissioned and now serves as the main injector for the APS linac, essentially replacing the Koontz-type DC gun. To help ensure injector availability, particularly with the advent of top-up mode operation at the APS, a second thermionic-cathode rf gun will be installed in the APS linac to act as a hot-spare beam source. The hot-spare installation includes several unique design features, including a deep-orbit Panofsky-style alpha magnet. Details of the hot-spare beamline design and projected performance are presented, along with some plans for future performance upgrades.

  20. Status and Operation of the Linac4 Ion Source Prototypes

    CERN Document Server

    Lettry, J; Andersson, P; Bertolo, S; Butterworth, A; Coutron, Y; Dallocchio, A; Chaudet, E; Gil-Flores, J; Guida, R; Hansen, J; Koszar, I; Mahner, E; Mastrostefano, C; Mathot, S; Mattei, S; Midttun, O; Moyret, P; Nisbet, D; O’Neil, M; Paoluzzi, M; Pasquino, C; Pereira, H; Rochez, J; Sanchez Alvarez, J; Sanchez Arias, J; Scrivens, R; Steyaert, D; Thaus, N; Hatayama, A; Nishida, K; Shibata, T; Yamamot, T; Otha, M

    2014-01-01

    CERN’s Linac4 45 kV H- ion sources prototypes are installed at a dedicated ion source test stand and in the Linac4 tunnel. The operation of the pulsed hydrogen injection, RF sustained plasma and pulsed high voltages are described. The first experimental results of two prototypes relying on 2MHz RF- plasma heating are presented. The plasma is ignited via capacitive coupling, and sustained by inductive coupling. The light emitted from the plasma is collected by viewports pointing to the plasma chamber wall in the middle of the RF solenoid and to the plasma chamber axis. Preliminary measurements of optical emission spectroscopy and photometry of the plasma have been performed. The design of a cesiated ion source is presented. The volume source has produced a 45 keV H- beam of 16-22 mA which has successfully been used for the commissioning of the LEBT, RFQ and chopper of Linac4.

  1. 400-MeV upgrade for the Fermilab linac

    Energy Technology Data Exchange (ETDEWEB)

    Young, D.E.; Noble, R.J.

    1989-09-01

    Fermilab plans to upgrade the Tevatron to expand the physics research program in both the fixed target and the collider operating modes. The first phase of this program is to increase the energy of the H{sup -} linac from 200 to 400 MeV in order to reduce the incoherent space change tuneshift at injection into the Booster which can limit either the brightness or the total intensity of the beam. The linac upgrade will be achieved by replacing the last four 201 MeV, with seven 805 MHz side-coupled cavity modules operating at an average axial field of about 8 MV/m. This will allow acceleration to 400 MeV in the existing Linac enclosure. 4 refs., 3 figs., 1 tab.

  2. Beam loading compensation for the NLC low frequency linacs

    Energy Technology Data Exchange (ETDEWEB)

    Li, Z.; Miller, R.; Farkas, D.; Raubenheimer, T.; Tang, H.; Yeremian, D.

    1997-03-01

    The NLC low rf linacs are heavily loaded by a beam of about 130 ns in macropulse length (90 bunches) and a current up to 2.75 Amps. Beam loading voltage generates a large energy spread along the bunch train. This energy spread is critical for lattice design and, if not properly compensated, induces emittance growth and in turn lowers the luminosity of the machine. In this paper, the authors study the {Delta}F and {Delta}T beam loading compensation techniques for the NLC low rf linacs. They will apply these methods to the NLC low rf linacs to demonstrate the efficacy of these methods. Finally, they discuss a hybrid {Delta}T + {Delta}F method to improve the efficiency of beam loading compensation.

  3. High-Performance Beam Simulator for the LANSCE Linac

    Energy Technology Data Exchange (ETDEWEB)

    Pang, Xiaoying [Los Alamos National Laboratory; Rybarcyk, Lawrence J. [Los Alamos National Laboratory; Baily, Scott A. [Los Alamos National Laboratory

    2012-05-14

    A high performance multiparticle tracking simulator is currently under development at Los Alamos. The heart of the simulator is based upon the beam dynamics simulation algorithms of the PARMILA code, but implemented in C++ on Graphics Processing Unit (GPU) hardware using NVIDIA's CUDA platform. Linac operating set points are provided to the simulator via the EPICS control system so that changes of the real time linac parameters are tracked and the simulation results updated automatically. This simulator will provide valuable insight into the beam dynamics along a linac in pseudo real-time, especially where direct measurements of the beam properties do not exist. Details regarding the approach, benefits and performance are presented.

  4. Particle-In-Cell Simulation of RFQ in SSC - Linac

    CERN Document Server

    Chen, Xiao; You-Jin, Yuan; Yong, Liu; Jia-Wen, Xia; Yuan-Rong, Lu; Batygin, Yuri

    2010-01-01

    A 52MHz Radio Frequency Quadrupole (RFQ) linear accelerator (linac) is designed to serve as an initial structure for the SSC-linac system (injector into Separated Sector Cyclotron). The designed injection and output energy are 3.5 keV/u and 143 keV/u, respectively. Beam dynamics study in RFQ was done using 3-dimensional particle-in-cell code BEAMPATH [1]. Simulation results show that this RFQ structure is characterized by stable value of beam transmission efficiency (at least 95%) for both zero-current mode and for space charge dominated regime. The beam accelerated in RFQ has good quality in both transversal and longitudinal directions, and could be easily accepted by Drift Tube Linac (DTL). Effects of vane errors and of the space charge on beam parameters are studied as well to define the engineering tolerance for RFQ vane machining and alignment.

  5. Beam Commissioning Plan and Result of KOMAC Linac

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Jiho; Kwon, Hyeokjung; Kim, Hansung; Cho, Yongsub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-05-15

    This work summarized the present status and near-future plan of the beam commissioning. The development and installation of the 100-MeV proton linac were finished. Beam commissioning is scheduled in May 2013. Hence we hope we can report the initial beam commissioning result in the spring meeting of Korea Nuclear Society. The beam commissioning of the KOMAC (Korea Multi-Purpose Accelerator Complex) 100-MeV proton linear accelerator is in progress. The linac includes a 50-keV ion source, a 3-MeV RFQ (radio frequency quadrupole), a 100-MeV DTL (drift tube linac). The final goal of the beam commissioning is accelerating 100-MeV proton beams to the beam dump in the accelerator tunnel and into a target room.

  6. Reliability and Availability Studies in the RIA Linac Driver

    CERN Document Server

    Schnirman-Lessner, Eliane

    2005-01-01

    The RIA facility will include various complex systems and must provide radioactive beams to many users simultaneously. The availability of radioactive beams for most experiments at the fully-commissioned facility should be as high as possible within design cost limitations. To make a realistic estimate of the achievable reliability a detailed analysis is required. The RIA driver linac is a complex machine containing a large number of SC resonators and capable of accelerating multiple-charge-state beams. At the pre-CDR stage of the design it is essential to identify critical facility subsystem failures that can prevent the driver linac from operating. The reliability and availability of the driver linac are studied using expert information and data from operating machines such as ATLAS, APS, JLab, and LANL. Availability studies are performed with a Monte-Carlo simulation code previously applied to availability assessments of the NLC facility [http://www.slac.stanford.edu/xorg/accelops/Full/LCoptsfull] and the ...

  7. Status and experiece with the alignment of Linac4

    CERN Document Server

    Fuchs, Jean-Frederic

    2016-01-01

    LINAC4 (L4) is an H- linear accelerator that will deliver, for the High Luminosity LHC (HL-LHC) project requirements, a beam of protons at 160 MeV energy to the PS complex and then to the LHC. Its connection to the PS booster will take place during the Long Shutdown 2 (LS2) in 2019-2020 or earlier if any major failure of the LINAC2. The Linac4 project requires the precise alignment with a tolerance of about +/- 0.2 mm in both the horizontal and vertical planes, of elements along approximately 150 m beam line. This paper will give a status, an overview of the challenges of the alignment, the issues solved by the survey section, the techniques and methodology used to realise the survey activities over the last five years.

  8. TLD determination of neutron dose contribution in medical linac

    Energy Technology Data Exchange (ETDEWEB)

    Cano, A.; Rivera, T.; Calderon A, J. A. [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Legaria 694, Col. Irrigacion, 11500 Mexico D. F. (Mexico); Azorin, J. [Universidad Autonoma Metropolitana, Unidad Iztapalapa, San Rafael Atlixco 186, Col. Vicentina, 09340 Mexico D. F. (Mexico); Villasenor N, L. F. [Hospital General de Mexico, Dr. Balmis No. 148, Col. Doctores, 06726 Mexico D. F. (Mexico); Vega C, H. R., E-mail: azorin@xanum.uam.m [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Calle Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2011-02-15

    The increased use of Linacs with accelerating voltage higher than 10 MV in clinical radiotherapy is producing and increasing demand of accurate dosimetric measurements of the photon induced neutron contamination of the radiotherapy beams, due that the associated Bremsstrahlung X rays may produce neutrons as a result of subsequent photonuclear reactions with the different materials constituting the accelerator head. Thermal neutron fluences can be measured with TLD-600/TLD-700 pairs arranged in both a bare and a cadmium (Cd) foil covered methacry-late box. Neutron response of Tl dosemeters irradiated with two different neutron sources has been investigated. The shape of the glow curve of these TLDs after irradiation in a medical Linac and in a Pu Be neutron source has been studied to verify the contribution of neutrons to an additional dose to staff, patients and the general public, due to photonuclear reactions generating neutrons from medical Linacs. (Author)

  9. Tunneling in superconducting structures

    Science.gov (United States)

    Shukrinov, Yu. M.

    2010-12-01

    Here we review our results on the breakpoint features in the coupled system of IJJ obtained in the framework of the capacitively coupled Josephson junction model with diffusion current. A correspondence between the features in the current voltage characteristics (CVC) and the character of the charge oscillations in superconducting layers is demonstrated. Investigation of the correlations of superconducting currents in neighboring Josephson junctions and the charge correlations in neighboring superconducting layers reproduces the features in the CVC and gives a powerful method for the analysis of the CVC of coupled Josephson junctions. A new method for determination of the dissipation parameter is suggested.

  10. Superconductivity in doped insulators

    Energy Technology Data Exchange (ETDEWEB)

    Emery, V.J. [Brookhaven National Lab., Upton, NY (United States); Kivelson, S.A. [California Univ., Los Angeles, CA (United States). Dept. of Physics

    1995-12-31

    It is shown that many synthetic metals, including high temperature superconductors are ``bad metals``, with such a poor conductivity that the usual meanfield theory of superconductivity breaks down because of anomalously large classical and quantum fluctuations of the phase of the superconducting order parameter. It is argued that the supression of a first order phase transition (phase separation) by the long-range Coulomb interaction leads to high temperature superconductivity accompanied by static or dynamical charge inhomogeneIty. Evidence in support of this picture for high temperature superconductors is described.

  11. Symptom dimensions of the SCL-90-R: a test of the tripartite model of anxiety and depression.

    Science.gov (United States)

    Steer, R A; Clark, D A; Ranieri, W F

    1994-06-01

    To determine the extent to which the SCL-90-R assesses general distress or specific dimensions of psychopathology, two principal components analyses were conducted based on 900 outpatients diagnosed with mixed psychiatric disorders. The first component explained 30.5% of the total variance and was interpreted as reflecting overall symptom distress. Partialling the first component out of the correlations among the symptoms in a second principal components analysis, we found four specific residual components reflecting somatic anxiety, depression, irritability, and attention problems. The results were discussed as partially supporting Clark and Watson's (1991) tripartite model of anxiety and depression.

  12. Programación de Controladores Lógicos (PLC) mediante Ladder y Lenguaje de Control Estructurado (SCL) en MATLAB

    OpenAIRE

    Heyder David Páez-Logreira; Ronald Zamora-Musa; José Bohórquez-Pérez

    2015-01-01

    Existen diferentes lenguajes de programación de Controladores Lógicos Programables (PLC), el más común de ellos es el lenguaje de programación gráfico para autómatas programables llamado LADDER. Sin embargo, el lenguaje LADDER no es amigable en programas que requieren de cálculos de ecuaciones matemáticas, por ejemplo, el cálculo del volumen de un tanque en un control de nivel. Lenguajes alternativos como el Lenguaje de Control Estructurado (SCL) son menos estudiados dada su complejidad y poc...

  13. Programación de Controladores Lógicos (PLC) mediante Ladder y Lenguaje de Control Estructurado (SCL) en MATLAB

    OpenAIRE

    Heyder David Páez-Logreira; Ronald Zamora-Musa; José Bohórquez-Pérez

    2015-01-01

    Existen diferentes lenguajes de programación de Controladores Lógicos Programables (PLC), el más común de ellos es el lenguaje de programación gráfico para autómatas programables llamado LADDER. Sin embargo, el lenguaje LADDER no es amigable en programas que requieren de cálculos de ecuaciones matemáticas, por ejemplo, el cálculo del volumen de un tanque en un control de nivel. Lenguajes alternativos como el Lenguaje de Control Estructurado (SCL) son menos estudiados dada su complejidad y poc...

  14. RF Operation for the 100MeV Proton Linac

    Energy Technology Data Exchange (ETDEWEB)

    Seol, Kyung Tae; Kwon, Hyeok Jung; Kim, Dae Il; Kim, Han Sung; Song, Young Gi; Jang, Ji Ho; Cho, Yong Sub [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    The RF systems for the 100MeV linac were constructed. The HPRF system including klystrons, circulators, high power dummy loads, and waveguide components was installed at the klystron gallery, and the LLRF control systems including a commercial FPGA module and a LLRF analog chassis were also installed. The phase stability of the RF reference line was measured with S11 phase under temperature control. The RF systems for 100MeV linac have been operated for a beam commissioning, and the 100MeV proton beam has been supplied to users currently. The RF systems of the 100MeV proton linac for the KOMAC (KOrea Multi-purpose Accelerator Complex) were installed at the Gyeong-ju site. The 100MeV linac consists of a 3MeV RFQ, a 20MeV DTL with four tanks, two MEBT tanks, and seven 100MeV DTL tanks. For the 100MeV linac, nine sets of LLRF control systems and the HPRF systems including 1MW klystrons, circulators and waveguide components have been installed at the klystron gallery, and four high voltage converter modulators to drive nine klystrons have been installed at the modulator room. A RF reference system distributing 300MHz LO signal to each RF control system has also been installed with a temperature control system at the klystron gallery. The requirement of RF field control is within +/- 1% in RF amplitude and +/- 1 degree in RF phase. The RF systems have been operated for the beam commissioning. The installation and operation of the RF system for the 100MeV proton linac are presented in this paper.

  15. Application of electron linacs in medicine, food sterilization and synchrotron light sources

    Science.gov (United States)

    Tran, Duc-Tien

    1989-04-01

    A review of the state of the art and new trends in electron linac technology is given with emphasis on three particular applications: radiotherapy, food sterilization and synchrotron light sources. The requirements on linac performances that these applications call for, namely energy variation flexibility, high power, high energy and low cost, will open linacs to new applications to come.

  16. Beam Dynamics Design Studies of a Superconducting Radioactive Ion Beam Post-accelerator

    CERN Document Server

    Fraser, MA; Pasini, M

    2011-01-01

    The HIE-ISOLDE project at CERN proposes a superconducting upgrade to increase the energy range and quality of the radioactive ion beams produced at ISOLDE, which are currently post- accelerated by the normal conducting REX linac. The specification and design choices for the HIE-ISOLDE linac are outlined along with a comprehensive beam dynamics study undertaken to understand and mitigate the sources of beam emittance dilution. The dominant cause of transverse emittance growth was attributed to the coupling between the transverse and longitudinal motions through the phase dependence of the rf defocusing force in the accelerating cavities. A parametric resonance induced by the coupling was observed and its excitation surveyed as a function of trans- verse phase advance using numerical simulations and analytic models to understand and avoid the regions of transverse beam instability. Other sources of emittance growth were studied and where necessary ameliorated, including the beam steering force in the quarter-wa...

  17. Beam dynamics design studies of a superconducting radioactive ion beam postaccelerator

    CERN Document Server

    Fraser, M A; Jones, R M

    2011-01-01

    The HIE-ISOLDE project at CERN proposes a superconducting upgrade to increase the energy range and quality of the radioactive ion beams produced at ISOLDE, which are currently postaccelerated by the normal conducting radioactive ion beam experiment linac. The specification and design choices for the HIE-ISOLDE linac are outlined along with a comprehensive beam dynamics study undertaken to understand and mitigate the sources of beam emittance dilution. The dominant cause of transverse emittance growth was attributed to the coupling between the transverse and longitudinal motions through the phase dependence of the rf defocusing force in the accelerating cavities. A parametric resonance induced by the coupling was observed and its excitation surveyed as a function of transverse phase advance using numerical simulations and analytic models to understand and avoid the regions of transverse beam instability. Other sources of emittance growth were studied and where necessary ameliorated, including the beam steering...

  18. RF characteristics of IHQ linac for heavy ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Ito, T.; Sasa, K.; Hayashizaki, N.; Isokawa, K.; Hattori, T. [Tokyo Inst. of Tech. (Japan). Research Lab. for Nuclear Reactors; Osvath, E. [Institute of Atomic Physics, Institute of Physics and Nuclear Engineering, P.O. Box MG-6, Bucharest (Romania); Schubert, H. [HSI, Tuerkenstrasse 28, 80333 Muenchen (Germany)

    1998-04-01

    At Tokyo institute of technology (TIT), an interdigital-H type quadrupole (IHQ) linac has been constructed for application in high energy heavy ion implantation. The linac can accelerate particles with charge to mass ratio greater than 1/16 from 0.24 MeV up to 1.6 MeV (for {sup 16}O{sup +}). As a result of the low power test, the resonant frequency is 36.26 MHz, the shunt impedance is 252 M{Omega}/m and therefore, the required power to accelerate {sup 16}O{sup +} ion is 39.5 kW. (orig.) 8 refs.

  19. Low power test of IHQ linac for heavy ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Takashi; Sasa, Kimikazu; Hayashizaki, Noriyosu; Isokawa, Katsushi; Hattori, Toshiyuki [Tokyo Inst. of Tech. (Japan). Research Lab. for Nuclear Reactors; Osvath, E.; Schubert, H.

    1997-12-31

    At Tokyo Institute of Technology (TIT), An Interdigital-H type Quadrupole (IHQ) linac has been constructed for application of high energy heavy ion implantation. The linac can accelerate the particles with charge to mass ratio grater than 1/16 from 0.48 MeV up to 1.6 MeV (for {sup 16}O{sup +}). As a result of the low power test, the resonant frequency is 36.26 MHz and the shunt impedance is 252 M{Omega}/m. Therefore, required power to accelerate {sup 16}O{sup +} ion is 39.5 kW. (author)

  20. RF characteristics of IHQ linac for heavy ion implantation

    Science.gov (United States)

    Ito, Takashi; Osvath, E.; Sasa, Kimikazu; Hayashizaki, Noriyosu; Isokawa, Katsushi; Schubert, H.; Hattori, Toshiyuki

    1998-04-01

    At Tokyo Institute of Technology (TIT), an Interdigital-H type Quadrupole (IHQ) linac has been constructed for application in high energy heavy ion implantation. The linac can accelerate particles with charge to mass ratio greater than 1/16 from 0.24 MeV up to 1.6 MeV (for 16O +). As a result of the low power test, the resonant frequency is 36.26 MHz, the shunt impedance is 252 MΩ/m and therefore, the required power to accelerate 16O + ion is 39.5 kW.

  1. Micro-SHINE Uranyl Sulfate Irradiations at the Linac

    Energy Technology Data Exchange (ETDEWEB)

    Youker, Amanda J. [Argonne National Lab. (ANL), Argonne, IL (United States); Kalensky, Michael [Argonne National Lab. (ANL), Argonne, IL (United States); Chemerisov, Sergey [Argonne National Lab. (ANL), Argonne, IL (United States); Schneider, John [Argonne National Lab. (ANL), Argonne, IL (United States); Byrnes, James [Argonne National Lab. (ANL), Argonne, IL (United States); Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-08-01

    Peroxide formation due to water radiolysis in a uranyl sulfate solution is a concern for the SHINE Medical Technologies process in which Mo-99 is generated from the fission of dissolved low enriched uranium. To investigate the effects of power density and fission on peroxide formation and uranyl-peroxide precipitation, uranyl sulfate solutions were irradiated using a 50-MeV electron linac as part of the micro-SHINE experimental setup. Results are given for uranyl sulfate solutions with both high and low enriched uranium irradiated at different linac powers.

  2. Neutron distribution and induced activity inside a Linac treatment room.

    Science.gov (United States)

    Juste, B; Miró, R; Verdú, G; Díez, S; Campayo, J M

    2015-01-01

    Induced radioactivity and photoneutron contamination inside a radiation therapy bunker of a medical linear accelerator (Linac) is investigated in this work. The Linac studied is an Elekta Precise electron accelerator which maximum treatment photon energy is 15 MeV. This energy exceeds the photonuclear reaction threshold (around 7 MeV for high atomic number metals). The Monte Carlo code MCNP6 has been used for quantifying the neutron contamination inside the treatment room for different gantry rotation configuration. Walls activation processes have also been simulated. The approach described in this paper is useful to prevent the overexposure of patients and medical staff.

  3. Equivalent circuit for postcoupler stabilization in a drift tube linac

    Directory of Open Access Journals (Sweden)

    Francesco Grespan

    2012-01-01

    Full Text Available Postcouplers (PCs are devices used in order to reduce the effect of perturbations on the operating mode of a drift tube linac (DTL, using the resonant coupling stabilization method. In this article an equivalent circuit for a DTL equipped with PCs is presented, together with a 3D simulation analysis, which can explain the principle of postcoupler stabilization and define a new tuning strategy for DTL cavities. The PC tuning procedure based on the equivalent circuit and on frequency measurements has been tested and validated with measurements on the Linac4 DTL aluminum model, present at CERN.

  4. Equivalent circuit for postcoupler stabilization in a drift tube linac

    Science.gov (United States)

    Grespan, Francesco

    2012-01-01

    Postcouplers (PCs) are devices used in order to reduce the effect of perturbations on the operating mode of a drift tube linac (DTL), using the resonant coupling stabilization method. In this article an equivalent circuit for a DTL equipped with PCs is presented, together with a 3D simulation analysis, which can explain the principle of postcoupler stabilization and define a new tuning strategy for DTL cavities. The PC tuning procedure based on the equivalent circuit and on frequency measurements has been tested and validated with measurements on the Linac4 DTL aluminum model, present at CERN.

  5. Beam position monitor for energy recovered linac beams

    Energy Technology Data Exchange (ETDEWEB)

    Powers, Thomas; Evtushenko, Pavel

    2017-06-06

    A method of determining the beam position in an energy recovered linac (ERL). The method makes use of in phase and quadrature (I/Q) demodulation techniques to separate the pickup signal generated by the electromagnetic fields generated by the first and second pass beam in the energy recovered linac. The method includes using analog or digital based I/Q demodulation techniques in order to measure the relative amplitude of the signals from a position sensitive beam pickup such as a button, strip line or microstripline beam position monitor.

  6. Operation of the superconducting RF photo gun at ELBE

    CERN Document Server

    Teichert, J; Buettig, H; Janssen, D; Justus, M; Lehnert, U; Michel, P; Murcek, P; Schneider, Ch; Schurig, R; Staufenbiel, F; Xiang, R; Kamps, T; Rudolph, J; Schenk, M; Klemz, G; Will, I

    2012-01-01

    As the first superconducting RF photo-injector (SRF gun) in practical operation, the SRF gun has been successfully connected to the superconducting linac ELBE at Forschungzentrum Dresden-Rossendorf. The injection with this new gun will improve the beam quality for the users of the radiation source. The SRF gun contains a 3½ cell superconducting accelerating cavity with a frequency of 1.3 GHz. The design is for use of normal conducting photocathodes. At present, caesium telluride photocathodes are applied which are illuminated by an ultraviolet laser beam. The kinetic energy of the produced electron beam is 3 MeV which belongs to a peak electric field of 16 MV/m in the cavity. The maximum bunch charge which is obtained and measured in a Faraday cup is about 400 pC (20 μA average current at a repetition rate of 50 kHz). The SRF gun injector is connected to the ELBE accelerator via a dogleg with two 45° deflection magnets. This connection beam line was commissioned in January 2010. A first beam injection into...

  7. Operation of the superconducting RF photo gun at ELBE

    CERN Document Server

    Teichert, J; Buettig, H; Janssen, D; Justus, M; Lehnert, U; Michel, P; Murcek, P; Schneider, C; Schurig, R; Staufenbiel, F; Xiang, R; Kamps, T; Rudolph, J; Schenk, M; Klemz, G; Will, I

    2011-01-01

    As the first superconducting RF photo-injector (SRF gun) in practical operation, the SRF gun has been successfully connected to the superconducting linac ELBE at Forschungzentrum Dresden-Rossendorf. The injection with this new gun will improve the beam quality for the users of the radiation source. The SRF gun contains a 3½ cell superconducting accelerating cavity with a frequency of 1.3 GHz. The design is for use of normal conducting photocathodes. At present, caesium telluride photocathodes are applied which are illuminated by an ultraviolet laser beam. The kinetic energy of the produced electron beam is 3 MeV which belongs to a peak electric field of 16 MV/m in the cavity. The maximum bunch charge which is obtained and measured in a Faraday cup is about 400 pC (20 µA average current at a repetition rate of 50 kHz). The SRF gun injector is connected to the ELBE accelerator via a dogleg with two 45° deflection magnets. This connection beam line was commissioned in January 2010. A first beam injection into...

  8. Construct Validity of Symptom Checklist-90-Revised (SCL-90-R and General Health Questionnaire-28 (GHQ-28 in Patients with Drug Addiction and Diabetes, and Normal Population

    Directory of Open Access Journals (Sweden)

    Abolfazl ARDAKANI

    2016-04-01

    Full Text Available Background: Given that validity is the baseline of psychological assessments, there is a need to provide evidence-based data for construct validity of such scales to advance the clinicians for evaluating psychiatric morbidity in psychiatric and psychosomatic setting.Methods: This comparative cross-sectional study aimed to investigate the construct validity of the Malaysian version of the GHQ-28 and the SCL-90-R. The sample comprised 660 individuals including diabetics, drug dependents, and normal population. The research scales were administered to the participants. Convergent and discriminant validity of both scales were investigated by Confirmatory Factor Analysis (CFA using AMOS. The Pearson correlation coefficient was utilized to obtain the relationship between the two scales. Results: The internal consistency of the GHQ-28 and SCL-90-R were highly acceptable, and confirmatory factor analysis confirmed the convergent validity of both scales. The results of this study revealed that the construct validity of GHQ-28 was acceptable, whereas discriminant validity of SCL-90-R was not adequate. According to Pearson correlation coefficient the relationships between three common subscales of the GHQ-28 and SCL-90-R were significantly positive; somatization (r=0.671, P<0.01, Anxiety (r=0.728, P<0.01, and Depression (r=0.660, P <0.01.Conclusions: This study replicated the construct of the Malaysian version of GHQ-28, yet failed to support the nine-factor structure of the SCL-90-R. Therefore, multidimensionality of the SCL-90-R as clinical purposes is questionable, and it may be a better unitary measure for assessing and screening mental disorders. Further research need to be carried out to prove this finding.Keywords: SCL-90-R, GHQ-28, Construct validity, Mental health

  9. Enfermedad pulmonar intersticial en Esclerosis Sistémica : diferencia en la presentación clínica y evolución clínica y evolución entre pacientes con anticuerpos Scl-70 frente PM-Scl

    OpenAIRE

    Guillén del Castillo, Alfredo

    2013-01-01

    La esclerosis sistémica (ES) es una enfermedad autoinmune multisistémica que afecta de forma variable a diferentes órganos. En el pulmón produce la enfermedad pulmonar intersticial difusa (EPID), cuyo pronóstico difiere según el autoanticuerpo asociado. Se estudiaron las características clínicas y espirométricas de 63 pacientes diagnosticados de ES y EPID, con positividad para anti-Scl-70 o anti-PM-Scl. En el grupo anti-Scl-70 se documentó mayor prevalencia de úlceras digitales y afección gas...

  10. Superconducting wind turbine generators

    DEFF Research Database (Denmark)

    Abrahamsen, Asger Bech; Mijatovic, Nenad; Seiler, Eugen

    2010-01-01

    , the main challenge of the superconducting direct drive technology is to prove that the reliability is superior to the alternative drive trains based on gearboxes or permanent magnets. A strategy of successive testing of superconducting direct drive trains in real wind turbines of 10 kW, 100 kW, 1 MW and 10...... offshore turbines of 8 and 10 MW have been determined from an up-scaling of an existing 5 MW turbine and the necessary properties of the superconducting drive train are discussed. We have found that the absence of the gear box is the main benefit and the reduced weight and size is secondary. However...... MW generator and it is concluded that the present production capacity of coated conductors must be increased by a factor of 36 by 2020, resulting in a ten times lower price of the tape in order to reach a realistic price level for the superconducting drive train....

  11. Magnetic and superconducting nanowires

    DEFF Research Database (Denmark)

    Piraux, L.; Encinas, A.; Vila, L.

    2005-01-01

    magnetic and superconducting nanowires. Using different approaches entailing measurements on both single wires and arrays, numerous interesting physical properties have been identified in relation to the nanoscopic dimensions of these materials. Finally, various novel applications of the nanowires are also...

  12. Superconductivity fundamentals and applications

    CERN Document Server

    Buckel, Werner

    2004-01-01

    This is the second English edition of what has become one of the definitive works on superconductivity in German -- currently in its sixth edition. Comprehensive and easy to understand, this introductory text is written especially with the non-specialist in mind. The authors, both long-term experts in this field, present the fundamental considerations without the need for extensive mathematics, describing the various phenomena connected with the superconducting state, with liberal insertion of experimental facts and examples for modern applications. While all fields of superconducting phenomena are dealt with in detail, this new edition pays particular attention to the groundbreaking discovery of magnesium diboride and the current developments in this field. In addition, a new chapter provides an overview of the elements, alloys and compounds where superconductivity has been observed in experiments, together with their major characteristics. The chapter on technical applications has been considerably expanded...

  13. Superconductivity and symmetry breaking

    Energy Technology Data Exchange (ETDEWEB)

    Sarasua, L.G., E-mail: sarasua@fisica.edu.uy [Instituto de Fisica, Facultad de Ciencias, Universidad de la Republica, Montevideo (Uruguay)

    2012-02-15

    In the present work we consider the relation between superconductivity and spontaneous gauge symmetry breaking (SGBS). We show that ODLRO does not require in principle SBGS, even in the presence of particle number fluctuations, by examining exact solutions of a fermionic pairing model. The criteria become equivalent if a symmetry breaking field is allowed, which can be attributed to the interaction with the environment. However, superconducting states without SBGS are not forbidden.

  14. Photoemission, Correlation and Superconductivity:

    Science.gov (United States)

    Abrecht, M.; Ariosa, D.; Cloëtta, D.; Pavuna, D.; Perfetti, L.; Grioni, M.; Margaritondo, G.

    We review some of the problems still affecting photoemission as a probe of high-temperature superconductivity, as well as important recent results concerning their solution. We show, in particular, some of the first important results on thin epitaxial films grown by laser ablation, which break the monopoly of cleaved BCSCO in this type of experiments. Such results, obtained on thin LSCO, may have general implications on the theory of high-temperature superconductivity.

  15. Emergent Higgsless Superconductivity

    Directory of Open Access Journals (Sweden)

    Cristina Diamantini M.

    2017-01-01

    Full Text Available We present a new Higgsless model of superconductivity, inspired from anyon superconductivity but P- and T-invariant and generalizable to any dimension. While the original anyon superconductivity mechanism was based on incompressible quantum Hall fluids as average field states, our mechanism involves topological insulators as average field states. In D space dimensions it involves a (D-1-form fictitious pseudovector gauge field which originates from the condensation of topological defects in compact lowenergy effective BF theories. There is no massive Higgs scalar as there is no local order parameter. When electromagnetism is switched on, the photon acquires mass by the topological BF mechanism. Although the charge of the gapless mode (2 and the topological order (4 are the same as those of the standard Higgs model, the two models of superconductivity are clearly different since the origins of the gap, reflected in the high-energy sectors are totally different. In 2D thi! s type of superconductivity is explicitly realized as global superconductivity in Josephson junction arrays. In 3D this model predicts a possible phase transition from topological insulators to Higgsless superconductors.

  16. Superconducting Fullerene Nanowhiskers

    Directory of Open Access Journals (Sweden)

    Yoshihiko Takano

    2012-04-01

    Full Text Available We synthesized superconducting fullerene nanowhiskers (C60NWs by potassium (K intercalation. They showed large superconducting volume fractions, as high as 80%. The superconducting transition temperature at 17 K was independent of the K content (x in the range between 1.6 and 6.0 in K-doped C60 nanowhiskers (KxC60NWs, while the superconducting volume fractions changed with x. The highest shielding fraction of a full shielding volume was observed in the material of K3.3C60NW by heating at 200 °C. On the other hand, that of a K-doped fullerene (K-C60 crystal was less than 1%. We report the superconducting behaviors of our newly synthesized KxC60NWs in comparison to those of KxC60 crystals, which show superconductivity at 19 K in K3C60. The lattice structures are also discussed, based on the x-ray diffraction (XRD analyses.

  17. High temperature interfacial superconductivity

    Science.gov (United States)

    Bozovic, Ivan [Mount Sinai, NY; Logvenov, Gennady [Port Jefferson Station, NY; Gozar, Adrian Mihai [Port Jefferson, NY

    2012-06-19

    High-temperature superconductivity confined to nanometer-scale interfaces has been a long standing goal because of potential applications in electronic devices. The spontaneous formation of a superconducting interface in bilayers consisting of an insulator (La.sub.2CuO.sub.4) and a metal (La.sub.1-xSr.sub.xCuO.sub.4), neither of which is superconducting per se, is described. Depending upon the layering sequence of the bilayers, T.sub.c may be either .about.15 K or .about.30 K. This highly robust phenomenon is confined to within 2-3 nm around the interface. After exposing the bilayer to ozone, T.sub.c exceeds 50 K and this enhanced superconductivity is also shown to originate from a 1 to 2 unit cell thick interfacial layer. The results demonstrate that engineering artificial heterostructures provides a novel, unconventional way to fabricate stable, quasi two-dimensional high T.sub.c phases and to significantly enhance superconducting properties in other superconductors. The superconducting interface may be implemented, for example, in SIS tunnel junctions or a SuFET.

  18. Runx1-mediated hematopoietic stem-cell emergence is controlled by a Gata/Ets/SCL-regulated enhancer

    Science.gov (United States)

    Nottingham, Wade T.; Jarratt, Andrew; Burgess, Matthew; Speck, Caroline L.; Cheng, Jan-Fang; Prabhakar, Shyam; Rubin, Eddy M.; Li, Pik-Shan; Sloane-Stanley, Jackie; Kong-a-San, John

    2007-01-01

    The transcription factor Runx1/AML1 is an important regulator of hematopoiesis and is critically required for the generation of the first definitive hematopoietic stem cells (HSCs) in the major vasculature of the mouse embryo. As a pivotal factor in HSC ontogeny, its transcriptional regulation is of high interest but is largely undefined. In this study, we used a combination of comparative genomics and chromatin analysis to identify a highly conserved 531-bp enhancer located at position + 23.5 in the first intron of the 224-kb mouse Runx1 gene. We show that this enhancer contributes to the early hematopoietic expression of Runx1. Transcription factor binding in vivo and analysis of the mutated enhancer in transient transgenic mouse embryos implicate Gata2 and Ets proteins as critical factors for its function. We also show that the SCL/Lmo2/Ldb-1 complex is recruited to the enhancer in vivo. Importantly, transplantation experiments demonstrate that the intronic Runx1 enhancer targets all definitive HSCs in the mouse embryo, suggesting that it functions as a crucial cis-regulatory element that integrates the Gata, Ets, and SCL transcriptional networks to initiate HSC generation. PMID:17823307

  19. Programación de Controladores Lógicos (PLC mediante Ladder y Lenguaje de Control Estructurado (SCL en MATLAB

    Directory of Open Access Journals (Sweden)

    Heyder David Páez-Logreira

    2015-05-01

    Full Text Available Existen diferentes lenguajes de programación de Controladores Lógicos Programables (PLC, el más común de ellos es el lenguaje de programación gráfico para autómatas programables llamado LADDER. Sin embargo, el lenguaje LADDER no es amigable en programas que requieren de cálculos de ecuaciones matemáticas, por ejemplo, el cálculo del volumen de un tanque en un control de nivel. Lenguajes alternativos como el Lenguaje de Control Estructurado (SCL son menos estudiados dada su complejidad y poca popularidad en la pequeña y mediana industria. En este artículo se compara los resultados del lenguaje de programación LADDER y el lenguaje SCL generado mediante la herramienta Simulink® PLC Coder de MATLAB® tomando como caso de estudio el cálculo de volumen de un tanque. Finalmente, este trabajo demuestra que la herramienta Simulink® PLC Coder presenta una alternativa de desarrollo más eficiente.

  20. Mass, Light and Colour of the Cosmic Web in the Supercluster SCL2243-0935 (z=0.447)

    CERN Document Server

    Schirmer, Mischa; Kuijken, Konrad; Erben, Thomas

    2011-01-01

    Context: In 2.2m MPG-ESO/WFI data we discovered several mass peaks through weak lensing, forming a possible supercluster at redshift 0.45. Through multi-colour wide-field imaging with CFHT/Megaprime and INT/WFC we identify early-type galaxies and trace the supercluster network with them. Through EMMI/NTT multi-object spectroscopy we verify the initial shear-selected cluster candidates. Using weak lensing we obtain mass estimates for the supercluster centre and the filaments. Results: We identified the centre of the SCL2243-0935 supercluster, MACS J2243-0935, which was found independently by Ebeling et al. (2010). 13 more clusters or overdensities are embedded in a filamentary network, half of them are already spectroscopically confirmed. Three (5-15) Mpc filaments are detected, and we estimate the global size of SCL2243 to 45x15x50 Mpc, making it one of the largest superclusters known at intermediate redshifts. Weak lensing yields r_200=(2.06+/-0.13) Mpc and M_200=(1.54+/-0.29)x10^15 M_sun for MACS J2243 with...

  1. Cryogenic test of the 4 K / 2 K insert for the ARIEL e-Linac cryomodule

    Energy Technology Data Exchange (ETDEWEB)

    Laxdal, R. E.; Ma, Y.; Harmer, P.; Kishi, D.; Koveshnikov, A.; Muller, N.; Vrielink, A. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC (Canada); O' Brien, M. [University of British Columbia, Vancouver (Canada); Ahammed, M. [Variable Energy Cyclotron Center, Kolkata (India)

    2014-01-29

    The ARIEL project at TRIUMF requires a 50 MeV superconducting electron linac consisting of five nine cell 1.3 GHz cavities divided into three cryomodules with one, two and two cavities in each module respectively. LHe is distributed in parallel to each module at 4 K and at ∼1.2 bar. Each module has a cryogenic insert on board that receives the 4 K liquid and produces 2 K into a cavity phase separator. The module combines a 4 K phase separator, a plate and fin heat exchanger from DATE and a J-T valve expanding into the 2 K phase separator. The unit also supplies 4 K liquid to thermal intercepts in the module in siphon loops that return the vaporized liquid to the 4 K reservoir. For testing purposes the unit is outfitted with a dummy 2 K phase separator and thermal intercepts with variable heaters that mimic the final heat loads in order to test the cryogenic performance. The design of the 4 K / 2 K insert, the results of the cold tests and a summary of the test infrastructure including cryogenics services will be presented.

  2. Structural Basis for LMO2-Driven Recruitment of the SCL:E47bHLH Heterodimer to Hematopoietic-Specific Transcriptional Targets

    Directory of Open Access Journals (Sweden)

    Kamel El Omari

    2013-07-01

    Full Text Available Cell fate is governed by combinatorial actions of transcriptional regulators assembling into multiprotein complexes. However, the molecular details of how these complexes form are poorly understood. One such complex, which contains the basic-helix-loop-helix heterodimer SCL:E47 and bridging proteins LMO2:LDB1, critically regulates hematopoiesis and induces T cell leukemia. Here, we report the crystal structure of (SCL:E47bHLH:LMO2:LDB1LID bound to DNA, providing a molecular account of the network of interactions assembling this complex. This reveals an unexpected role for LMO2. Upon binding to SCL, LMO2 induces new hydrogen bonds in SCL:E47, thereby strengthening heterodimer formation. This imposes a rotation movement onto E47 that weakens the heterodimer:DNA interaction, shifting the main DNA-binding activity onto additional protein partners. Along with biochemical analyses, this illustrates, at an atomic level, how hematopoietic-specific SCL sequesters ubiquitous E47 and associated cofactors and supports SCL’s reported DNA-binding-independent functions. Importantly, this work will drive the design of small molecules inhibiting leukemogenic processes.

  3. 武夷学院2011级新生SCL-90测查与分析%The SCL-90's Test and Analysis on Freshmen in Grade 2011 of Wuyi University

    Institute of Scientific and Technical Information of China (English)

    刘少英

    2012-01-01

    To explore the status of freshmen from Wuyi University in order to carry effectively out mental health education and clinical psychological guidance. Methods: Symptom Checklist-90 (SCL-90) was appl/ed to freshmen from Wuyi University in 2011.2987 samples were valid. Results: Freshmen from the University had significantly lower total mean score and lower each mean score than the corre- sponding national norm of China(2008) (P〈O.01 or P〈0.001). Male students had significantly lower total mean score and lower each mean score of four factors (Somatization, Depression, Anxiety, phobia anxiety,) than female students (P ≤ 0.01 or O.05〈P ≤ 0.01). The singletons and the non singletons were no significant difference, only different in two factors (hostility, phobia anxiety) (P≤0.01 or O.05〈P≤0.01). Freshmen coming from countryside and coming from towns and cities were no significant difference (P〉O.O5).The Monthly household in- come(800-1500& 2000-50OO)was no significant difference (P〉0.05). The freshmen's entrance satisfaction had significantly lower total mean score and each mean score than the freshmen's entrance dissatisfied (P≤0.01). Conclusion: The status of freshmen have good performance overall. Some groups should be Pay special attention .then the level of mental health of female students and non singletons and freshmen's entrance dissatisfied is lower than the others.%目的:探讨和分析武夷学院大学新生心理健康状况,以便有效地进行心理健康教育和临床心理辅导。方法:采用症状自评量表(SCL-90)对武夷学院2011级校本部大学新生进行全面测查,有效样本2987份。结果:该校2011级新生SCL-90总均分以及各因子均值分都显著低于全国常模(P〈0.001或P〈0.01);男生SCL-90总均分以及躯体化、抑郁、焦虑、恐怖4个因子各自均分都显著低于女生(P≤O.01或0.05〈P≤O.01);是否为独生子女SCL-90得分差异并不显

  4. The superconducting spin valve and triplet superconductivity

    Science.gov (United States)

    Garifullin, I. A.; Leksin, P. V.; Garif`yanov, N. N.; Kamashev, A. A.; Fominov, Ya. V.; Schumann, J.; Krupskaya, Y.; Kataev, V.; Schmidt, O. G.; Büchner, B.

    2015-01-01

    A review of our recent results on the spin valve effect is presented. We have used a theoretically proposed spin switch design F1/F2/S comprising a ferromagnetic bilayer (F1/F2) as a ferromagnetic component, and an ordinary superconductor (S) as the second interface component. Based on it we have prepared and studied in detail a set of multilayers CoOx/Fe1/Cu/Fe2/S (S=In or Pb). In these heterostructures we have realized for the first time a full spin switch effect for the superconducting current, have observed its sign-changing oscillating behavior as a function of the Fe2-layer thickness and finally have obtained direct evidence for the long-range triplet superconductivity arising due to noncollinearity of the magnetizations of the Fe1 and Fe2 layers.

  5. Beam Line Design and Beam Physics Study of Energy Recovery Linac Free Electron Laser at Peking University

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Guimei [Peking Univ., Beijing (China)

    2011-12-31

    Energy recovering linac (ERL) offers an attractive alternative for generating intense beams of charged particles by approaching the operational efficiency of a storage ring while maintaining the superior beam quality typical of a linear accelerator. In ERLs, the decelerated beam cancels the beam loading effects of the accelerated beam with high repetition rate. Therefore, ERLs can, in principle, accelerate very high average currents with only modest amounts of RF power. So the efficiency of RF power to beam is much higher. Furthermore, the energy of beam to dump is lower, so it will reduce dump radiation. With the successful experiments in large maximum-to-injection energy ratio up to 51:1 and high power FEL up to 14kW, the use of ERL, especially combining with superconducting RF technology, provides a potentially powerful new paradigm for generation of the charged particle beams used in MW FEL, synchrotron radiation sources, high-energy electron cooling devices and so on. The 3+1/2 DC-SC photo injector and two 9cell TESLA superconducting cavity for IR SASE FEL in PKU provides a good platform to achieve high average FEL with Energy Recovery. The work of this thesis is on Beam line design and Beam dynamics study of Energy Recovery Linac Free Electron Laser for Peking University. It is the upgrade of PKU facility, which is under construction. With ERL, this facility can work in CW mode, so it can operate high average beam current without RF power constraint in main linac and generate high average FEL power. Moreover, it provides a test facility to study the key technology in ERL. System parameters are optimized for PKU ERL-FEL. The oscillation FEL output power is studied with different bunch charge, transverse emittance, bunch length and energy spread. The theory of optimal RF power and Q{sub ext} with ERL and without ERL is analyzed and applied to PKU injector and linac including microphonic effect. pace charge effect in the injector and merger is studied for beam

  6. Superconducting Undulator with Variably Polarized Light

    CERN Document Server

    Hwang, Ching Shiang; Ching Fan, Tai; Li, W P; Lin, P H

    2004-01-01

    This study investigates planar in-vacuo superconducting undulators with periodic length of 5 cm (IVSU5) producing linearly and circularly polarized infrared rays or xrays source. The vertically wound racetrack coil is selected for the coil and pole fabrication of the IVSU5. When the up and down magnetic pole arrays with alternative directions rotated wires in the horizontal plane, a helical field radiates circularly polarized light in the electron storage ring, the free electron laser (FEL), and the energy recovery linac (ERL) facilities. Meanwhile, an un-rotated wire is constructed together with the rotated wire on the same undulator is used to switch the linear horizontal and vertical, the right- and left-circular polarization radiation. Given a periodic length of 5 cm and a gap of 23 mm, the maximum magnetic flux density in the helical undulator are Bz = 1.5 T and Bx = 0.5 T when the wires rotated by 20°. This article describes the main factors of the planar and helical undulator design for FEL and...

  7. Conceptual Design for the New RPI 2020 Linac

    Energy Technology Data Exchange (ETDEWEB)

    Adolphsen, C.; Bane, K.; Dolgashev, V.; Jensen, A.; Haase, A.; Jongewaard, E.; Kemp, M.; Krasnykh, A.; Lewandowski, J.; Li, Z.; Neilson, J.; Pearson, C.; Tantawi, S.; Wang, J.; Yeremian, A.D.; /SLAC; Brand, P.; Danon, Y.; /Rensselaer Polytech. Inst.; Epping, B.; Donovan, T.; Block, R.; Leinweber, G.; /Knolls Atomic Power Lab.

    2014-10-29

    The Rensselaer Polytechnic Institute (RPI) spectrometer is an installation based on an L-band linear accelerator designed and installed many decades ago. While this installation has served many important experiments over the decades, a new more powerful and more flexible linac to serve a wider range of experiments is envisioned as an upgrade to the existing installation by 2020.

  8. Linac4: injecting new life into the LHC

    CERN Multimedia

    Antonella Del Rosso

    2015-01-01

    Construction work is nearing completion on the ion source for Linac4, the new linear accelerator that forms part of the LHC injector upgrade programme. Here we find out more about this essential component of the accelerator chain, designed and built at CERN.     The image shows the Linac4 H- source. The red light is the alpha line of the visible hydrogen emission spectrum. The ion source is a key component of Linac4, the linear accelerator that from 2018 will supply H- ions (hydrogen atoms with an extra electron) at 160 MeV for injection into the accelerator complex. As the only ion source at CERN, Linac4 must be highly reliable, which requires a full understanding of the production mechanisms, the simulation of physical processes and the validation of those processes through experimentation. “This source is the result of much fruitful collaboration,” says Jacques Lettry of the BE department. “Its design was inspired by the many sources of th...

  9. Progress on LINAC 4 : Civil engineering (28/07/2009)

    CERN Multimedia

    CERN Video Productions

    2009-01-01

    The commissioning of the new Linac4 source – first element of the new acceleration chain for the upgrade of the LHC (sLHC) – has started beginning of July. After years of preparation but after only a few hours of fine-tuning of the numerous parameters involved, the source has delivered its first negative ions.

  10. Test Measurements with the REX-ISOLDE LINAC Structures

    CERN Document Server

    Kester, O; Sieber, T; Emhofer, S; Rudolph, K; von Hahn, R; Podlech, H; Repnow, R; Schwalm, D; Ratzinger, U; Schempp, A

    2000-01-01

    The Radioactive Beam Experiment {REX-ISOLDE} [1,2] is a pilot experiment at ISOLDE (CERN) testing the new concept of post acceleration of radioactive ion beams by using charge breeding of the ions in a high charge state ion source and the efficient acceleration of the highly charged ions in a short LINAC using modern ion accelerator structures. In order to prepare the ions for the experiments singly charged radioactive ions from the on-line mass separator ISOLDE will be cooled and bunched in a Penning trap, charge bred in an electron beam ion source (EBIS) and finally accelerated in the LINAC. The LINAC consists of a radio frequency quadrupole (RFQ) accelerator, which accelerates the ions up to 0.3 MeV/u, an 20 gap interdigital H-type (IH) structure with a final energy between 1.1 and 1.2 MeV/u and three seven gap resonators, which allow the variation of the final energy between 0.8-2.2 MeV/u. A variety of tests with REXTRAP, REXEBIS and the LINAC structures have been done, in order to study their capabilitie...

  11. Full power to the first Linac4 module

    CERN Multimedia

    Francesco Poppi

    2010-01-01

    Since last week the first of a total of 23 accelerating structures for Linac4 has been undergoing high-power tests. Although still a prototype, this structure is destined to be the first of the 12 PIMS cavities to be installed in the Linac4 tunnel and it has been completely designed, developed and constructed at CERN.   The PIMS prototype. The new Linac4 has 4 different types of accelerating structures. The PI-Mode Structures (PIMS) are the last stage and are designed to accelerate protons up to 160 MeV. “PIMS have never before been used to accelerate protons”, explains Frank Gerigk, the project engineer responsible for the Linac4 accelerating structures. “In LEP, they were used to accelerate electrons, and now we have modified them and improved several design features to make them suitable for protons”. The first prototype was entirely manufactured in the CERN workshop. Due to the size of the pieces it was difficult to achieve and preserve the required to...

  12. Design and analysis of X-band femtosecond linac

    Energy Technology Data Exchange (ETDEWEB)

    Uesaka, M.; Kozawa, T.; Takeshita, A.; Kobayashi, T.; Ueda, T.; Miya, K. [Tokyo Univ., Tokai, Ibaraki (Japan). Nuclear Engineering Research Lab.

    1997-03-01

    Femtosecond quantum phenomena research project is proposed at Nuclear Engineering Research Laboratory, University of Tokyo. The research facility consists of an X-band (11.424GHz) femtosecond electron linac, a femtosecond wavelength tunable laser, two S-band (2.856GHz) picosecond electron linacs and measuring equipments. Especially, we aim to generate a 100 fs (FWHM) electron single bunch with more than 1 nC at the X-band femtosecond linac. Ultrafast processes in radiation physics, chemistry, material science and microscopic electromagnetic phenomena are going to be analyzed there. Here the design and analysis of an X-band femtosecond linac is presented. The simulation of electron dynamics is carried out including magnetic pulse compression by using PARMELA and SUPERFISH. It is found by the simulation that the 600 ps (tail-to-tail) electron emission from a 200 kV thermionic gun can be bunched and compressed to 110 fs (FWHM) with the charge of 0.8 nC which gives 7.3 kA. We plan to use one high power X-band klystron which can supply 60 MW with more than 200 ns pulse duration. The flatness of plateau of the pulse should be 0.2% for stable ultrashort bunch generation. (author)

  13. An Energy Recovery Electron Linac On Ring Collider

    Energy Technology Data Exchange (ETDEWEB)

    Nikolitsa Merminga; Geoffrey Krafft; Valeri Lebedev; Ilan Ben-Zvi

    2001-09-01

    Electron-proton/ion colliders with center of mass energies between 14 GeV and 100 GeV (protons) or 63 GeV/A (ions) and luminosities at the 10{sup 33} (per nucleon) level have been proposed recently as a means for studying hadronic structure. Electron beam polarization appears to be crucial for many of the experiments. Two accelerator design scenarios have been examined in detail: colliding rings and recirculating linac-on-ring. Although the linac-on-ring scenario is not as well developed as the ring-ring scenario, comparable luminosities appear feasible. The linac-on-ring option presents significant advantages with respect to: (1) spin manipulations; (2) reduction of the synchrotron radiation load in the detectors; (3) a wide range of continuous energy variability. Rf power and beam dump considerations require that the electron linac recover the beam energy. This technology has been demonstrated at Jefferson Lab's IR FEL with cw current up to 5 mA and beam energy up to 50 MeV. Based on extrapolations from actual measurements and calculations, energy recovery is expected to be feasible at higher currents (a few hundred mA) and higher energies (a few GeV) as well. The report begins with a brief overview of Jefferson Lab's experience with energy recovery and summarize its benefits. Luminosity projections for the linac-ring scenario based on fundamental limitations are presented next. The feasibility of an energy recovery electron linac-on-proton ring collider is investigated and four conceptual point designs are shown corresponding to electron to proton energies of: 3 GeV on 15 GeV, 5 GeV on 50 GeV and 10 GeV on 250 GeV, and for gold ions with 100 GeV/A. The last two designs assume that the protons or ions are stored in the existing RHIC accelerator. Accelerator physics issues relevant to proton rings and energy recovery linacs are discussed next and a list of required R and D for the realization of such a design is presented.

  14. RF Processing of the Couplers for the SNS Superconducting Cavities

    Energy Technology Data Exchange (ETDEWEB)

    Y.Kang; I.E. Campisi; D. Stout; A. Vassioutchenko; M. Stirbet; M. Drury; T. Powers

    2005-07-10

    All eighty-one fundamental power couplers for the 805 MHz superconducting cavities of the SNS linac have been RF conditioned and installed in the cryomodules successfully. The couplers were RF processed at JLAB or at the SNS in ORNL: more than forty couplers have been RF conditioned in the SNS RF Test Facility (RFTF) after the first forty couplers were conditioned at JLAB. The couplers were conditioned up to 650 kW forward power at 8% duty cycle in traveling and standing waves. They were installed on the cavities in the cryomodules and then assembled with the airside waveguide transitions. The couplers have been high power RF tested with satisfactory accelerating field gradients in the cooled cavities.

  15. Cre-/IoxP-Mediated Recombination between the SIL and SCL Genes Leads to a Block in T-Cell Development at the CD4-CD8- to CD4+CD8+ Transition

    Directory of Open Access Journals (Sweden)

    Yue Cheng

    2007-04-01

    Full Text Available In the most common form of stem cell leukemia (SCL gene rearrangement, an interstitial deletion of 82 kb brings SCL under the control of regulatory elements that normally govern expression of the ubiquitously expressed SCL interrupting locus (SIL gene, which is located directly upstream of SCL. To investigate the effect of this fusion in a mouse model, a bacterial artificial chromosome (BAC clone containing both human SIL and SCL genes was isolated, and IoxP sites were inserted into intron 1 of both the SIL and SCL genes, corresponding to the sites at which recombination occurs in human T-cell acute lymphocytic leukemia patients. This BAC clone was used to generate transgenic SILIoxloxSCL mice. These transgenic mice were subsequently bred to Lck-Cre mice that express the Cre recombinase specifically in the thymus. The BAC transgene was recombined between the two IoxP sites in over 50% of the thymocytes from SILIoxloxSCL/Cre double-transgenic mice, bringing the SCL gene under the direct control of SIL regulatory elements. Aberrant SCL gene expression in the thymus was verified by reverse transcription- polymerase chain reaction. Using FACS analysis, we found that mice carrying both SILIoxloxSCL and Cre transgenes have increased CD4-/CD8- thymocytes compared with transgenenegative mice. In the spleen, these transgenic mice show a marked reduction in the number of mature CD4+ or CD8+ cells. These results demonstrate that conditional activation of SCL under control of SIL regulatory elements can impair normal T-cell development.

  16. Frequency choice of eRHIC SRF linac

    Energy Technology Data Exchange (ETDEWEB)

    Xu, W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ben-Zvi, I. [Brookhaven National Lab. (BNL), Upton, NY (United States); Roser, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ptitsyn, V. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-01-05

    eRHIC is a FFAG lattice based multipass ERL [1]. The eRHIC SRF linac has been decided to change from 422 MHz 5-cell cavity to 647 MHz 5-cell cavity. There are several considerations affecting the frequency choice for a high current multipass-ERL: the beam structure, bunch length, energy spread, beam-break-up (BBU) threshold, SRF loss considerations. Beyond the physics considerations, cost and complexity or risk is an important consideration for the frequency choice, especially when we are designing a machine to be built in a few years. Although there are some benefits of using a 422 MHz cavity for eRHIC ERL, however, there are some very critical drawbacks, including lack of facilities to fabricate a 422 MHz 5-cell cavity, very few facilities to process such a cavity and no existing facility to test the cavity anywhere. As the cavity size is big and its weight is large, it is difficult to handle it during fabrication, processing and testing and no one has experience in this area. As the cavity size is large, the cryomodule becomes big as well. All of these considerations drive the risk of building eRHIC ERL with 422 MHz cavities to a very high level. Therefore, a decision was made to change the frequency of main linac to be 647 MHz 5-cell cavities. This note will compare these two linacs: 422MHz 5-cell cavity linac and 647Mz 5-cell cavity SRF linac, from both practical point of view and physics point of view.

  17. Cryostat for Testing HIE-Isolde Superconducting RF Cavities

    CERN Document Server

    Capatina, O; Cuccuru, G; Pasini, M; Renaglia, T; Therasse, M; Vullierme, B

    2011-01-01

    The High Intensity and Energy ISOLDE (HIE-ISOLDE) project is a major upgrade of the existing ISOLDE and REX-ISOLDE facilities at CERN [1], with the objective of increasing the energy and intensity of the delivered radioactive ion beams (RIB). This project aims to fill the request for a more energetic post-accelerated beam by means of a new superconducting (SC) linac based on Quarter Wave Resonators (QWR). A research and development (R&D) programme looking at all the different aspects of the SC linac started in 2008 and continued throughout 2010. The R&D effort has particularly focused on the development of the high β cavities (β = 10.3%) for which the Nb sputtered on Cu substrate technology has been adopted. Two prototype cavities were manufactured and are undergoing RF cold tests. The pre-series cavity manufacturing is under way using 3D forged Cu billets. A single vacuum cryostat was designed and built to test these cavities at liquid helium temperatures. This paper details the main design concep...

  18. Sensitivity of Niobium Superconducting RF Cavities to Magnetic Field

    CERN Document Server

    Gonnella, Dan

    2015-01-01

    Future particle accelerators such as the the SLAC "Linac Coherent Light Source-II" (LCLS-II) and the proposed Cornell Energy Recovery Linac (ERL) require hundreds of superconducting RF (SRF) cavities operating in continuous wave (CW) mode. In order to achieve economic feasibility of projects such as these, the cavities must achieve a very high intrinsic quality factor (Q0). In order to reach these high Q0's in the case of LCLS-II, nitrogen-doping has been proposed as a cavity preparation technique. When dealing with Q0's greater than 1x10^10, the effects of ambient magnetic field on Q0 become significant. Here we show that the sensitivity that a cavity has to ambient magnetic field is highly dependent on the cavity preparation. Specifically, standard electropolished and 120C baked cavities show a sensitivity of ~0.8 and ~0.6 nOhm/mG trapped, respectively, while nitrogen-doped cavities show a sensitivity of ~2 to 5 nOhm/mG trapped. Less doping results in weaker sensitivity. This difference in sensitivities is ...

  19. Cryogenic, superconducting and rf results of the SRFQ2 of PIAVE

    Indian Academy of Sciences (India)

    A M Porcellato; G Bisoffi; V Andreev; G Bassato; G Bezzon; S Canella; F Chiurlotto; A Lombardi; L Bertazzo; D Conventi; G Galeazzi; S Marigo; V Palmieri; F Poletto; T Shirai; S Y Stark; F Stivanello

    2002-12-01

    SRFQ2 is the second RFQ superconducting (SC) structure of PIAVE, the positive ion injector of the SC LINAC for heavy ions ALPI, in operation at Legnaro. During 2001, SRFQ2 was extensively tested at cryogenic temperature reaching its design performance, i.e., 280 kV inter-electrode voltage (equivalent to 25 MV/m peak surface electrical field) at 7 W dissipated power. This paper describes the treatments, the main difficulties arisen during the tests, the way they were overcome and the measurement sequences that allowed the characterization of SRFQ2 behavior. A brief description of future programs is also given.

  20. Electron Bunch Train Excited Higher-Order Modes in a Superconducting RF Cavity

    CERN Document Server

    Gao, Yongfeng; Wang, Fang; Feng, Liwen; Zhuang, Dehao; Lin, Lin; Zhu, Feng; Hao, Jiankui; Quan, Shengwen; Liu, Kexin

    2016-01-01

    Higher-order mode (HOM) based intra-cavity beam diagnostics has been proved effectively and conveniently in superconducting radio-frequency (SRF) accelerators. Our recent research shows that the beam harmonics in the bunch train excited HOM spectrum, which have much higher signal-to-noise ratio than the intrinsic HOM peaks, may also be useful for beam diagnostics. In this paper, we will present our study on bunch train excited HOMs, including the theoretic model and recent experiments carried out based on the DC-SRF photoinjector and SRF linac at Peking University.

  1. Construct Validity of Symptom Checklist-90-Revised (SCL-90-R) and General Health Questionnaire-28 (GHQ-28) in Patients with Drug Addiction and Diabetes, and Normal Population.

    Science.gov (United States)

    Ardakani, Abolfazl; Seghatoleslam, Tahereh; Habil, Hussain; Jameei, Fahimeh; Rashid, Rusdi; Zahirodin, Alireza; Motlaq, Farid; Masjidi Arani, Abbas

    2016-04-01

    Given that validity is the baseline of psychological assessments, there is a need to provide evidence-based data for construct validity of such scales to advance the clinicians for evaluating psychiatric morbidity in psychiatric and psychosomatic setting. This comparative cross-sectional study aimed to investigate the construct validity of the Malaysian version of the GHQ-28 and the SCL-90-R. The sample comprised 660 individuals including diabetics, drug dependents, and normal population. The research scales were administered to the participants. Convergent and discriminant validity of both scales were investigated by Confirmatory Factor Analysis (CFA) using AMOS. The Pearson correlation coefficient was utilized to obtain the relationship between the two scales. The internal consistency of the GHQ-28 and SCL-90-R were highly acceptable, and confirmatory factor analysis confirmed the convergent validity of both scales. The results of this study revealed that the construct validity of GHQ-28 was acceptable, whereas discriminant validity of SCL-90-R was not adequate. According to Pearson correlation coefficient the relationships between three common subscales of the GHQ-28 and SCL-90-R were significantly positive; somatization (r=0.671, P<0.01), Anxiety (r=0.728, P<0.01), and Depression (r=0.660, P <0.01). This study replicated the construct of the Malaysian version of GHQ-28, yet failed to support the nine-factor structure of the SCL-90-R. Therefore, multidimensionality of the SCL-90-R as clinical purposes is questionable, and it may be a better unitary measure for assessing and screening mental disorders. Further research need to be carried out to prove this finding.

  2. Nanoscience and Engineering in Superconductivity

    CERN Document Server

    Moshchalkov, Victor; Lang, Wolfgang

    2010-01-01

    For emerging energy saving technologies, superconducting materials with superior performance are needed. Such materials can be developed by manipulating the 'elementary building blocks' through nanostructuring. For superconductivity the 'elementary blocks' are Cooper pair and fluxon (vortex). This book presents new ways how to modify superconductivity and vortex matter through nanostructuring and the use of nanoscale magnetic templates. The basic nano-effects, vortex and vortex-antivortex patterns, vortex dynamics, Josephson phenomena, critical currents, and interplay between superconductivity

  3. Interface high-temperature superconductivity

    Science.gov (United States)

    Wang, Lili; Ma, Xucun; Xue, Qi-Kun

    2016-12-01

    Cuprate high-temperature superconductors consist of two quasi-two-dimensional (2D) substructures: CuO2 superconducting layers and charge reservoir layers. The superconductivity is realized by charge transfer from the charge reservoir layers into the superconducting layers without chemical dopants and defects being introduced into the latter, similar to modulation-doping in the semiconductor superlattices of AlGaAs/GaAs. Inspired by this scheme, we have been searching for high-temperature superconductivity in ultra-thin films of superconductors epitaxially grown on semiconductor/oxide substrates since 2008. We have observed interface-enhanced superconductivity in both conventional and unconventional superconducting films, including single atomic layer films of Pb and In on Si substrates and single unit cell (UC) films of FeSe on SrTiO3 (STO) substrates. The discovery of high-temperature superconductivity with a superconducting gap of ∼20 meV in 1UC-FeSe/STO has stimulated tremendous interest in the superconductivity community, for it opens a new avenue for both raising superconducting transition temperature and understanding the pairing mechanism of unconventional high-temperature superconductivity. Here, we review mainly the experimental progress on interface-enhanced superconductivity in the three systems mentioned above with emphasis on 1UC-FeSe/STO, studied by scanning tunneling microscopy/spectroscopy, angle-resolved photoemission spectroscopy and transport experiments. We discuss the roles of interfaces and a possible pairing mechanism inferred from these studies.

  4. Connectivity and superconductivity

    CERN Document Server

    Rubinstein, Jacob

    2000-01-01

    The motto of connectivity and superconductivity is that the solutions of the Ginzburg--Landau equations are qualitatively influenced by the topology of the boundaries, as in multiply-connected samples. Special attention is paid to the "zero set", the set of the positions (also known as "quantum vortices") where the order parameter vanishes. The effects considered here usually become important in the regime where the coherence length is of the order of the dimensions of the sample. It takes the intuition of physicists and the awareness of mathematicians to find these new effects. In connectivity and superconductivity, theoretical and experimental physicists are brought together with pure and applied mathematicians to review these surprising results. This volume is intended to serve as a reference book for graduate students and researchers in physics or mathematics interested in superconductivity, or in the Schrödinger equation as a limiting case of the Ginzburg--Landau equations.

  5. Large Superconducting Magnet Systems

    CERN Document Server

    Védrine, P.

    2014-07-17

    The increase of energy in accelerators over the past decades has led to the design of superconducting magnets for both accelerators and the associated detectors. The use of Nb−Ti superconducting materials allows an increase in the dipole field by up to 10 T compared with the maximum field of 2 T in a conventional magnet. The field bending of the particles in the detectors and generated by the magnets can also be increased. New materials, such as Nb3Sn and high temperature superconductor (HTS) conductors, can open the way to higher fields, in the range 13–20 T. The latest generations of fusion machines producing hot plasma also use large superconducting magnet systems.

  6. Functional expression of SCL/TAL1 interrupting locus (Stil) protects retinal dopaminergic cells from neurotoxin-induced degeneration.

    Science.gov (United States)

    Li, Jingling; Li, Ping; Carr, Aprell; Wang, Xiaokai; DeLaPaz, April; Sun, Lei; Lee, Eric; Tomei, Erika; Li, Lei

    2013-01-11

    We previously isolated a dominant mutation, night blindness b (nbb), which causes a late onset of retinal dopaminergic cell degeneration in zebrafish. In this study, we cloned the zebrafish nbb locus. Sequencing results revealed that nbb is a homolog of the vertebrate SCL/TAL1 interrupting locus (Stil). The Stil gene has been shown to play important roles in the regulation of vertebrate embryonic neural development and human cancer cell proliferation. In this study, we demonstrate that functional expression of Stil is also required for neural survival. In zebrafish, decreased expression of Stil resulted in increased toxic susceptibility of retinal dopaminergic cells to 6-hydroxydopamine. Increases in Stil-mediated Shh signaling transduction (i.e. by knocking down the Shh repressor Sufu) prevented dopaminergic cell death induced by neurotoxic insult. The data suggest that the oncogene Stil also plays important roles in neural protection.

  7. 安全检查表(SCL)在铁路劳动安全管理上的应用

    Institute of Scientific and Technical Information of China (English)

    刘国庆

    2011-01-01

    为保证铁路企业从业人员在运输生产过程中的健康安全,必须加强职业健康安全管理,把国际上普遍采用的职业健康安全管理体系(OHSMS,Occupational Health and Safety Management System) 的管理理念和管理技法之一的安全检查表(SCL,Safety Check List) 应用于铁路企业劳动安全管理上来.以期在铁路运输生产单位全力推行职业健康安全管理体系 (OHSMS) 认证.确保运输安全持续稳定.

  8. L'accompagnement infirmier du patient atteint de sclérose en plaques: travail de Bachelor

    OpenAIRE

    Al-Khudri, Tanya; Nunez de Almeida, Stéphanie; Ludwig, Catherine

    2014-01-01

    Le présent travail porte sur les déterminants de l’accompagnement infirmier à l’égard d’une personne atteinte de sclérose en plaques (SEP). La SEP est une maladie neurodégénérative, incurable et évolutive qui a des conséquences sur les sphères physiques, psychiques, sociales et spirituelles du patient, et par conséquent, elle requiert une prise en soin globale de la part de l’infirmière. Le traitement médicamenteux n’est pas suffisant pour ralentir l’évolution de cette affection, d’autres ser...

  9. Transcription of the SCL/TAL1 interrupting Locus (Stil) is required for cell proliferation in adult Zebrafish Retinas.

    Science.gov (United States)

    Sun, Lei; Li, Ping; Carr, Aprell L; Gorsuch, Ryne; Yarka, Clare; Li, Jingling; Bartlett, Michael; Pfister, Delaney; Hyde, David R; Li, Lei

    2014-03-07

    The human oncogene SCL/TAL1 interrupting locus (Stil) is highly conserved in vertebrate species. Previously, we identified a homolog of the Stil gene in zebrafish mutant (night blindness b, nbb), which showed neural defects in the retina (e.g. dopaminergic cell degeneration and/or lack of regeneration). In this research, we examined the roles of Stil in cell proliferation after degeneration in adult zebrafish retinas. We demonstrated that knockdown of Stil gene expression or inhibition of Sonic hedgehog (Shh) signaling transduction decreases the rate of cell proliferation. In contrast, activation of Shh signal transduction promotes cell proliferation. In nbb(+/-) retinas, inhibition of SUFU (a repressor in the Shh pathway) rescues the defects in cell proliferation due to down-regulation of Stil gene expression. The latter data suggest that Stil play a role in cell proliferation through the Shh signal transduction pathway.

  10. Transcription of the SCL/TAL1 Interrupting Locus (Stil) Is Required for Cell Proliferation in Adult Zebrafish Retinas*

    Science.gov (United States)

    Sun, Lei; Li, Ping; Carr, Aprell L.; Gorsuch, Ryne; Yarka, Clare; Li, Jingling; Bartlett, Michael; Pfister, Delaney; Hyde, David R.; Li, Lei

    2014-01-01

    The human oncogene SCL/TAL1 interrupting locus (Stil) is highly conserved in vertebrate species. Previously, we identified a homolog of the Stil gene in zebrafish mutant (night blindness b, nbb), which showed neural defects in the retina (e.g. dopaminergic cell degeneration and/or lack of regeneration). In this research, we examined the roles of Stil in cell proliferation after degeneration in adult zebrafish retinas. We demonstrated that knockdown of Stil gene expression or inhibition of Sonic hedgehog (Shh) signaling transduction decreases the rate of cell proliferation. In contrast, activation of Shh signal transduction promotes cell proliferation. In nbb+/− retinas, inhibition of SUFU (a repressor in the Shh pathway) rescues the defects in cell proliferation due to down-regulation of Stil gene expression. The latter data suggest that Stil play a role in cell proliferation through the Shh signal transduction pathway. PMID:24469449

  11. Design of a post linac for an energy upgrade of a heavy-ion injector

    Energy Technology Data Exchange (ETDEWEB)

    Iwata, Y., E-mail: y_iwata@nirs.go.jp; Noda, K.

    2014-07-15

    A post linac is being designed for an energy upgrade of a heavy-ion injector. This post linac is to be installed downstream of the formerly developed compact injector, consisting of an Electron-Cyclotron-Resonance Ion-Source (ECRIS), the Radio-Frequency-Quadrupole (RFQ) linac and the Alternating-Phase-Focused Interdigital H-mode Drift-Tube-Linac (APF IH-DTL). It is aimed to increase the output energy of a heavy-ion injector. Carbon ions are initially accelerated with the compact injector to 4 MeV/u, and further accelerated with the post linac up to 8 MeV/u. The three linacs have the same operating frequency of 200 MHz. For beam focusing of the post linac, the APF method is used. Iterative simulations of beam dynamics were performed to determine the optimum array of synchronous phases in each gap. The results of the simulations provided that the calculated efficiency of beam transmission through the post linac is as high as 98.4%. The total length of this APF post linac is estimated to be approximately 3 m. A design overview of the injector system including the post linac is presented.

  12. Design of a post linac for an energy upgrade of a heavy-ion injector

    Science.gov (United States)

    Iwata, Y.; Noda, K.

    2014-07-01

    A post linac is being designed for an energy upgrade of a heavy-ion injector. This post linac is to be installed downstream of the formerly developed compact injector, consisting of an Electron-Cyclotron-Resonance Ion-Source (ECRIS), the Radio-Frequency-Quadrupole (RFQ) linac and the Alternating-Phase-Focused Interdigital H-mode Drift-Tube-Linac (APF IH-DTL). It is aimed to increase the output energy of a heavy-ion injector. Carbon ions are initially accelerated with the compact injector to 4 MeV/u, and further accelerated with the post linac up to 8 MeV/u. The three linacs have the same operating frequency of 200 MHz. For beam focusing of the post linac, the APF method is used. Iterative simulations of beam dynamics were performed to determine the optimum array of synchronous phases in each gap. The results of the simulations provided that the calculated efficiency of beam transmission through the post linac is as high as 98.4%. The total length of this APF post linac is estimated to be approximately 3 m. A design overview of the injector system including the post linac is presented.

  13. Failed theories of superconductivity

    CERN Document Server

    Schmalian, Joerg

    2010-01-01

    Almost half a century passed between the discovery of superconductivity by Kammerlingh Onnes and the theoretical explanation of the phenomenon by Bardeen, Cooper and Schrieffer. During the intervening years the brightest minds in theoretical physics tried and failed to develop a microscopic understanding of the effect. A summary of some of those unsuccessful attempts to understand superconductivity not only demonstrates the extraordinary achievement made by formulating the BCS theory, but also illustrates that mistakes are a natural and healthy part of the scientific discourse, and that inapplicable, even incorrect theories can turn out to be interesting and inspiring.

  14. Fingerprints of Mott Superconductivity

    Institute of Scientific and Technical Information of China (English)

    王强华

    2003-01-01

    We improve a previous theory of doped Mott insulators with duality between pairing and magnetism by a further duality transform. As the result we obtained a quantum Ginzburg-Landau theory describing the Cooper pair condensate and the dual of spin condensate. We address the superconductivity by doping a Mott insulator,which we call the Mott superconductivity. Some fingerprints of such novelty in cuprates are the scaling between neutron resonance energy and superfluid density, and the induced quantized spin moment by vortices or Zn impurity (together with circulating charge super-current to be checked by experiments).

  15. Plasma characterization of the superconducting proton linear accelerator plasma generator using a 2 MHz compensated Langmuir probe.

    Science.gov (United States)

    Schmitzer, C; Kronberger, M; Lettry, J; Sanchez-Arias, J; Störi, H

    2012-02-01

    The CERN study for a superconducting proton Linac (SPL) investigates the design of a pulsed 5 GeV Linac operating at 50 Hz. As a first step towards a future SPL H(-) volume ion source, a plasma generator capable of operating at Linac4 or nominal SPL settings has been developed and operated at a dedicated test stand. The hydrogen plasma is heated by an inductively coupled RF discharge e(-) and ions are confined by a magnetic multipole cusp field similar to the currently commissioned Linac4 H(-) ion source. Time-resolved measurements of the plasma potential, temperature, and electron energy distribution function obtained by means of a RF compensated Langmuir probe along the axis of the plasma generator are presented. The influence of the main tuning parameters, such as RF power and frequency and the timing scheme is discussed with the aim to correlate them to optimum H(-) ion beam parameters measured on an ion source test stand. The effects of hydrogen injection settings which allow operation at 50 Hz repetition rate are discussed.

  16. 系统性硬化症(SSC)患者中拓扑异构酶Ⅰ(Scl-70)自身抗体与抗核抗体的检测%Systemic Sclerosis (SSC) Patients of Topoisomerase I (Scl-70) Detection of Autoantibodies and Anti Nuclear Antibody

    Institute of Scientific and Technical Information of China (English)

    尚洁

    2015-01-01

    目的:研究拓扑异构酶Ⅰ即为Scl-70自身抗体与抗核抗体在系统性硬化症(SSC)患者中检测的临床意义。方法选取系统性硬化症(SSC)患者150例,其中60例是弥散型,20例是局限型,20例是结缔组织病,50例是自身抗体阴性的健康人对照组。以间接免疫荧光法(IFA)检测抗核抗体。以免疫印迹法检测拓扑异构酶Ⅰ(Scl-70)自身抗体。间接免疫荧光法(IFA)检测抗核抗体阳性60例。结果免疫印迹法检测抗体拓扑异构酶Ⅰ(Scl-70)阳性21例(阳性率21%)。系统性硬化症(SSC)患者中拓扑异构酶Ⅰ(Scl-70)阳性10例,占56%,其中对照组均为阴性,拓扑异构酶Ⅰ(Scl-70)阳性者95%。而拓扑异构酶Ⅰ(Scl-70)的抗核抗体主要是分裂间期细胞核呈现均匀的荧光。核仁荧光加强而且也表现为均匀的荧光。结论标记拓扑异构酶Ⅰ(Scl-70)抗体阳性同时抗核抗体为分裂期间呈现的均匀的荧光,有助于系统性硬化症(SSC)患者的诊断。%Objective To study of topoisomerase I is scl-70 autoantibodies and anti nuclear antibody insystemic sclerosis ( SSC ) on the clinical signiifcance of detection of patients. Methods Selection of sustemic sclerosis ( SSC ) in 100 patients, in 60 cases which were dispersed type,20 cases are localized, case 20 is a connective tissue disease,50 cases of healthy people autoantibody negative control group by indirect immunofluorescence ( IFA ) detecting antibody. Detection of topoisomerase immunoblot ing ( Scl-70 ) antibody, Indirect immunolfuorescence assay ( IFA ) for detection of antinuclear antibodies were positive in 60 cases. Results Detection of antibodiea against topoisomerase I immunoblot assay ( scl-70 ) was positive in 21 cases(positive rate 21%), Systemic sclerosis ( SSC ) patients of topoisomerase I ( Scl-70 ) was positive in 10 cases. Accounted for 56%,The control group were negative, Topoisomerase

  17. Free-electron laser operation with a superconducting radio-frequency photoinjector at ELBE

    Energy Technology Data Exchange (ETDEWEB)

    Teichert, J., E-mail: j.teichert@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden (Germany); Arnold, A.; Büttig, H.; Justus, M. [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden (Germany); Kamps, T. [Helmholtz-Zentrum Berlin, Albert-Einstein-Str. 15, 12489 Berlin (Germany); Lehnert, U. [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden (Germany); Lu, P. [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden (Germany); Technische Universität Dresden, 01062 Dresden (Germany); Michel, P.; Murcek, P. [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden (Germany); Rudolph, J. [Helmholtz-Zentrum Berlin, Albert-Einstein-Str. 15, 12489 Berlin (Germany); Schurig, R.; Seidel, W. [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden (Germany); Vennekate, H. [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden (Germany); Technische Universität Dresden, 01062 Dresden (Germany); Will, I. [Max-Born-Institut, Berlin, Max-Born-Str. 2a, 12489 Berlin (Germany); Xiang, R. [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstr. 400, 01328 Dresden (Germany)

    2014-04-11

    At the radiation source ELBE a superconducting radio-frequency photoinjector (SRF gun) was developed and put into operation. Since 2010 the gun has delivered beam into the ELBE linac. A new driver laser with 13 MHz pulse repetition rate allows now to operate the free-electron lasers (FELs) with the SRF gun. This paper reports on the first lasing experiment with the far-infrared FEL at ELBE, describes the hardware, the electron beam parameters and the measurement of the FEL infrared radiation output. - Highlights: • The superconducting RF gun produces beam with Cs{sub 2}Te photocathodes. • The SRF gun operates as an injector for the ELBE linear accelerator. • First lasing of an infrared free-electron laser with an SRF gun.

  18. Towards a 100mA Superconducting RF Photoinjector for BERLinPro

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, Axel; Anders, W; Burrill, Andrew; Jankowiak, Andreas; Kamps, T; Knobloch, Jens; Kugeler, Oliver; Lauinger, P; Matveenko, A N; Schmeisser, M; Volker, J; Ciovati, Gianluigi; Kneisel, Peter; Nietubyc, R; Schubert, S G; Smedley, John; Sekutowicz, Jacek; Volkov, V; Will, I; Zaplatin, Evgeny

    2013-09-01

    For BERLinPro, a 100 mA CW-driven SRF energy recovery linac demonstrator facility, HZB needs to develop a photo-injector superconducting cavity which delivers a at least 1mm*mr emittance beam at high average current. To address these challenges of producing a high peak brightness beam at high repetition rate, at first HZB tested a fully superconducting injector with a lead cathode*,followed now by the design of a SC cavity allowing operation up to 4 mA using CW-modified TTF-III couplers and inserting a normal conducting high quantum efficiency cathode using the HZDR-style insert scheme. This talk will present the latest results and an overview of the measurements with the lead cathode cavity and will describe the design and optimization process, the first production results of the current design and an outlook to the further development steps towards the full power version.

  19. SQUID based cryogenic current comparator for measurements of the dark current of superconducting cavities

    Energy Technology Data Exchange (ETDEWEB)

    Vodel, W.; Nietzsche, S.; Neubert, R.; Nawrodt, R. [Friedrich Schiller Univ. Jena (Germany); Peters, A. [GSI Darmstadt (Germany); Knaack, K.; Wendt, M.; Wittenburg, K. [DESY Hamburg (Germany)

    2005-07-01

    The linear accelerator technology, based on super-conducting L-band (1.3 GHz) is currently under study at DESY (Hamburg, Germany). The two 10 km long main Linacs will be equipped with a total of nearly 20.000 cavities. The dark current due to the emission of electrons in these high gradient field super-conducting cavities is an unwanted particle source. A newly high performance SQUID based measurement system for detecting dark currents is proposed. It makes use of the Cryogenic Current Comparator principle and senses dark currents in the pA range with a measurement bandwidth of up to 70 kHz. The use of a cryogenic current comparator as dark current sensor has some important advantages: -) the measurement of the absolute value of the dark current, -) the non-dependence on the electron trajectories, -) the accurate absolute calibration with an additional wire loop, and -) extremely high resolution.

  20. Steady-state thermal studies on the HIE-ISOLDE high-$\\beta$ superconducting cavities

    CERN Document Server

    Alberty, L

    2013-01-01

    The activity of the High Intensity and Energy ISOLDE (HIE-ISOLDE) project aims to construct a superconducting linac based on 101.28 MHz niobium sputtered Quarter Wave Resonators (QWRs). For this, several prototypes of superconducting cavities are currently being developed at CERN using OFE copper as substrate material for Niobium film coating. Two main concepts are currently under development: one consists of rolled, machined, deepdrawed and welded parts; the other is based on machined parts which are put together using electron beam welding. This study presents the results of simulations carried out in order to assess the thermal performance of different designs. The interest for such analysis was raised up before launching the manufacture of the first industrial series, since both rolled and bulk approaches seemed possible.