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Sample records for rf linacs final

  1. Simplified RF power system for Wideroe-type linacs

    SciTech Connect

    Fugitt, J.; Howard, D.; Crosby, F.; Johnson, R.; Nolan, M.; Yuen, G.

    1981-03-01

    The RF system for the SuperHILAC injector linac was designed and constructed for minimum system complexity, wide dynamic range, and ease of maintenance. The final amplifier is close coupled to the linac and operates in an efficient semilinear mode, eliminating troublesome transmission lines, modulators, and high level regulators. The system has been operated at over 250 kW, 23 MHz with good regulation. The low level RF electronics are contained in a single chassis adjacent to the RF control computer, which monitors all important operating parameters. A unique 360/sup 0/ phase and amplitude modular is used for precise control and regulation of the accelerating voltage.

  2. Advanced RF power sources for linacs

    SciTech Connect

    Wilson, P.B.

    1996-10-01

    In order to maintain a reasonable over-all length at high center-of-mass energy, the main linac of an electron-positron linear collider must operate at a high accelerating gradient. For copper (non-superconducting) accelerator structures, this implies a high peak power per unit length and a high peak power per RF source, assuming a limited number of discrete sources are used. To provide this power, a number of devices are currently under active development or conceptual consideration: conventional klystrons with multi-cavity output structures, gyroklystrons, magnicons, sheet-beam klystrons, multiple-beam klystrons and amplifiers based on the FEL principle. To enhance the peak power produced by an rf source, the SLED rf pulse compression scheme is currently in use on existing linacs, and new compression methods that produce a flatter output pulse are being considered for future linear colliders. This paper covers the present status and future outlook for the more important rf power sources and pulse compression systems. It should be noted that high gradient electron linacs have applications in addition to high-energy linear colliders; they can, for example, serve as compact injectors for FEL`s and storage rings.

  3. A 10 MeV RF linac for industrial applications

    NASA Astrophysics Data System (ADS)

    Nayak, B.; Bhattacharjee, D.; Acharya, S.; Tillu, A. R.; Shivchandan; Chavan, R. B.; Choudhury, N.; Tiwari, R.

    2016-07-01

    This paper discusses the studies on a standing wave, biperiodic, on-axis coupled cavity RF linac operated at 2856 MHZ used for various industrial applications. Results of beam transmission experiments conducted in this accelerator have been presented. Analytical study and experimental verification of steady state beam loading in this facility have been explained. Finally some of the irradiation experiments performed in this system have been described.

  4. A self-adaptive feedforward rf control system for linacs

    NASA Astrophysics Data System (ADS)

    Zhang, Renshan; Ben-Zvi, Ilan; Xie, Jialin

    1993-01-01

    The design and performance of a self-adaptive feedforward rf control system are reported. The system was built for the linac of the Accelerator Test Facility (ATF) at Brookhaven National Laboratory. Variables of time along the linac macropulse, such as field or phase are discretized and represented as vectors. Upon turn-on or after a large change in the operating-point, the control system acquires the response of the system to test signal vectors and generates a linearized system response matrix. During operation an error vector is generated by comparing the linac variable vectors and a target vector. The error vector is multiplied by the inverse of the system's matrix to generate a correction vector is added to an operating point vector. This control system can be used to control a klystron to produce flat rf amplitude and phase pulses, to control a rf cavity to reduce the rf field fluctuation, and to compensate the energy spread among bunches in a rf linac. Beam loading effects can be corrected and a programmed ramp can be produced. The performance of the control system has been evaluated on the control of a klystron's output as well as an rf cavity. Both amplitude and phase have been regulated simultaneously. In initial tests, the rf output from a klystron has been regulated to an amplitude fluctuation of less than ±0.3% and phase variation of less than ±0.6°. The rf field of the ATF's photo-cathode microwave gun cavity has been regulated to ±0.5% in amplitude and simultaneously to ±1° in phase. Regulating just the rf field amplitude in the rf gun cavity, we have achieved amplitude fluctuation of less than ±0.2%.

  5. Overview and status of RF systems for the SSC Linac

    SciTech Connect

    Mynk, J.; Grippe, J.; Cutler, R.I.; Rodriguez, R.

    1993-05-01

    The Superconducting Super Collider (SSC) Linear Accelerator (Linac) produces a 600-MeV, 35-{mu}s, H-beam at a 10-Hz repetition rate. The beam is accelerated by a series of RF cavities. These consist of a Radio Frequency Quadrupole (RFQ), two bunchers, and four Drift Tube Linac (DTL) tanks at 427.617 MHz, and two bunchers, nine side-coupled Linac modules, and an energy compressor at 1282.851 MHz. The RFQ amplifier and the low-frequency buncher cavity amplifiers use gridded tubes, while the other cavities use klystron amplifier systems. The RF control system consists of a reference line and cavity feedback and feedforward loops for each amplifier. The RF amplifier system for each of these accelerator cavities is described, and the current status of each system is presented.

  6. A RF--linac, FEL based drive beam injector for CLIC

    SciTech Connect

    Barletta, W.A. Department of Physics, UCLA, 405 Hilgard Avenue, Los Angeles, California ); Bonifacio, R. )

    1992-07-01

    We describe a means of producing at train of 40 kA pulses of 3 ps duration as the drive beam for CLIC using an RF--linac driven free electron laser (FEL) buncher. Potential debunching effecs are discussed. Finally we describe a low energy test experiment.

  7. RF linac designs with beams in thermal equilibrium

    NASA Astrophysics Data System (ADS)

    Reiser, Martin; Brown, Nathan

    1996-06-01

    Beams in conventional radio-frequency linear accelerators (rf linacs) usually have a transverse temperature which is much larger than the longitudinal temperature. With high currents, space charge forces couple the transverse and longitudinal particle motions, driving the beam toward thermal equilibrium, which leads to emittance growth and halo formation. A design strategy is proposed in which the beam has equal transverse and longitudinal temperatures through the entire linac, avoiding these undesirable effects. For such equipartitioned linac beams, simple analytical relationships can be derived for the bunch size, tune depression, and other parameters as a function of beam intensity, emittance, and external focusing. These relations were used to develop three conceptual designs for a 938 MeV, 100 mA proton linac with different tune depressions, which are presented in this paper.

  8. Conceptual Design for Replacement of the DTL and CCL with Superconducting RF Cavities in the Spallation Neutron Source Linac

    SciTech Connect

    Champion, Mark S; Doleans, Marc; Kim, Sang-Ho

    2013-01-01

    The Spallation Neutron Source Linac utilizes normal conducting RF cavities in the low energy section from 2.5 MeV to 186 MeV. Six Drift Tube Linac (DTL) structures accelerate the beam to 87 MeV, and four Coupled Cavity Linac (CCL) structures provide further acceleration to 186 MeV. The remainder of the Linac is comprised of 81 superconducting cavities packaged in 23 cryomodules to provide final beam energy of approximately 1 GeV. The superconducting Linac has proven to be substantially more reliable than the normal conducting Linac despite the greater number of stations and the complexity associated with the cryogenic plant and distribution. A conceptual design has been initiated on a replacement of the DTL and CCL with superconducting RF cavities. The motivation, constraints, and conceptual design are presented.

  9. RF system considerations for large high-duty-factor linacs

    SciTech Connect

    Lynch, M.T.; Ziomek, C.D.; Tallerico, P.J.; Regan, A.H.; Eaton, L.; Lawrence, G.

    1994-09-01

    RF systems are often a major cost item for linacs, but this is especially true for large high-duty-factor linacs (up to and including CW) such as the Accelerator for Production of Tritium (APT) or the Accelerator for Transmutation of nuclear Waste (ATW). In addition, the high energy and high average beam current of these machines (approximately 1 GeV, 100--200 mA) leads to a need for excellent control of the accelerating fields in order to minimize the possibility of beam loss in the accelerator and the resulting activation. This paper will address the key considerations and limitations in the design of the RF system. These considerations impact the design of both the high power RF components and the RF controls. As might be expected, the two concerns sometimes lead to conflicting design requirements. For example minimum RF operating costs lead to a desire for operation near saturation of the high power RF generators in order to maximize the operating efficiency. Optimal control of the RF fields leads to a desire for maximum overdrive capability in those same generators in order to respond quickly to disturbances of the accelerator fields.

  10. A PROCEDURE TO SET PHASE AND AMPLITUDE OF THE RF IN THE SNS LINAC'S SUPERCONDUCTING CAVITIES

    SciTech Connect

    L.M. YOUNG

    2001-06-01

    This paper describes a procedure to set the phase and amplitude of the RF fields in the Spallation Neutron Source (SNS) linac's superconducting cavities. The linac uses superconducting cavities to accelerate the H{sup -} ion beam from the normal conducting linac at 185 MeV to a final energy of {approx}1 GeV. There are two types of cavities in the linac, 33 cavities with a geometric beta of 0.61 and 48 cavities with a geometric beta of 0.81. The correct phase setting of any single superconducting cavity depends on the RF phase and amplitude of all the preceding superconducting cavities. For the beam to be properly accelerated it must arrive at each cavity with a relative phase ({phi}{sub s}), called the synchronous phase, of about -20 degrees. That is, it must arrive early with respect to the phase at which it would gain the maximum energy by 20 degrees. This timing provides the longitudinal focusing. Beam particles arriving slightly later gain more energy and move faster relative to the synchronous beam particle. The problem is to set the phase and amplitude of each cavity in the linac so that the synchronous particle arrives at each cavity with the correct phase. The amplitude of each superconducting cavity will be adjusted as high as possible constrained only by the available RF power and the breakdown field of the cavity.

  11. Assessment of Alternative RF Linac Structures for APT

    SciTech Connect

    1997-03-26

    The APT program has been examining both normal and superconducting variants of the APT linac for the past two years. A decision on which of the two will be the selected technology will depend upon several considerations including the results of ongoing feasibility experiments, the performance and overall attractiveness of each of the design concepts, and an assessment of the system-level features of both alternatives. The primary objective of the Assessment of Alternative RF Linac Structures for APT study reported herein was to assess and compare, at the system-level, the performance, capital and life cycle costs, reliability/availability/maintainability (RAM) and manufacturing schedules of APT RF linear accelerators based upon both superconducting and normal conducting technologies. A secondary objective was to perform trade studies to explore opportunities for system optimization, technology substitution and alternative growth pathways and to identify sensitivities to design uncertainties.

  12. Simulation of waveguide FEL oscillator using RF linac

    SciTech Connect

    Kuruma, S.; Asakawa, M.; Imasaki, K.

    1995-12-31

    One dimensional multifrequency simulation code for waveguide mode FEL has been developed. Using this simulation code, we analyzed the spontaneous emission from electron micropulse from RF Linac. It is found that some parameters both high and low frequency waveguide modes are growing simultaneously, so the two radiation pulses are generated and amplified. And the experimental data for cavity length detuning of the radiation power are analyzed.

  13. Design Features and Initial RF Performance of a Gradient Hardened 17 GHz TW Linac Structure

    NASA Astrophysics Data System (ADS)

    Haimson, J.; Mecklenburg, B.

    2009-01-01

    To avoid surface erosion damage and to assist in studying RF breakdown thresholds in 17 GHz TW linac structures, a gradient hardened structure has been fabricated with high temperature brazed and machined stainless steel surfaces located in the peak E-field region of the beam apertures and the peak H-field regions of the input coupler cavity. The microwave design parameters and physical dimensions of this 22 cavity, 120 degree phase advance structure were chosen to allow the high gradient performance to be compared against a similar design all-copper structure that has been tested in a dual ring, power recirculating amplifier system. The final design parameters of the gradient hardened structure are discussed; the influence of stainless steel RF losses on the power buildup of the resonant ring and on the structure gradient distribution are described; waveforms are shown of the unique ability of the power amplifier to rapidly quench RF breakdown discharges in the linac structure by automatically sensing and redirecting the RF source power to a matched load; and preliminary test results during high power RF processing of the gradient hardened linac structure are presented.

  14. Design Features and Initial RF Performance of a Gradient Hardened 17 GHz TW Linac Structure

    SciTech Connect

    Haimson, J.; Mecklenburg, B.

    2009-01-22

    To avoid surface erosion damage and to assist in studying RF breakdown thresholds in 17 GHz TW linac structures, a gradient hardened structure has been fabricated with high temperature brazed and machined stainless steel surfaces located in the peak E-field region of the beam apertures and the peak H-field regions of the input coupler cavity. The microwave design parameters and physical dimensions of this 22 cavity, 120 degree phase advance structure were chosen to allow the high gradient performance to be compared against a similar design all-copper structure that has been tested in a dual ring, power recirculating amplifier system. The final design parameters of the gradient hardened structure are discussed; the influence of stainless steel RF losses on the power buildup of the resonant ring and on the structure gradient distribution are described; waveforms are shown of the unique ability of the power amplifier to rapidly quench RF breakdown discharges in the linac structure by automatically sensing and redirecting the RF source power to a matched load; and preliminary test results during high power RF processing of the gradient hardened linac structure are presented.

  15. The Development of the Linac Coherent Light Source RF Gun

    SciTech Connect

    Dowell, David H.; Jongewaard, Erik; Lewandowski, James; Limborg-Deprey, Cecile; Li, Zenghai; Schmerge, John; Vlieks, Arnold; Wang, Juwen; Xiao, Liling; /SLAC

    2008-09-24

    The Linac Coherent Light Source (LCLS) is the first x-ray laser user facility based upon a free electron laser (FEL) requiring extraordinary beam quality to saturate at 1.5 angstroms within a 100 meter undulator.[1] This new type of light source is using the last kilometer of the three kilometer linac at SLAC to accelerate the beam to an energy as high as 13.6 GeV and required a new electron gun and injector to produce a very bright beam for acceleration. At the outset of the project it was recognized that existing RF guns had the potential to produce the desired beam but none had demonstrated it. Therefore a new RF gun or at least the modification of an existing gun was necessary. The parameters listed in Table 1 illustrate the unique characteristics of LCLS which drive the requirements for the electron gun as given in Table 2. The gun beam quality needs to accommodate emittance growth as the beam is travels through approximately one kilometer of linac and two bunch compressors before reaching the undulator. These beam requirements were demonstrated during the recent commissioning runs of the LCLS injector and linac [2] due to the successful design, fabrication, testing and operation of the LCLS gun. The goal of this paper is to relate the technical background of how the gun was able to achieve and in some cases exceed these requirements by understanding and correcting the deficiencies of the prototype s-band RF photocathode gun, the BNL/SLAC/UCLA Gun III. This paper begins with a brief history and technical description of Gun III and the Gun Test Facility (GTF) at SLAC, and studies of the gun's RF and emittance compensation solenoid. The work at the GTF identified the gun and solenoid deficiencies, and helped to define the specifications for the LCLS gun. Section 1.1.5 describes the modeling used to compute and correct the gun RF fields and Section 1.1.6 describes the use of these fields in the electron beam simulations. The magnetic design and measurements of

  16. SRF and RF systems for LEReC Linac

    SciTech Connect

    Belomestnykh, S.; Ben-Zvi, I.; Brutus, J. C.; Fedotov, A.; McIntyre, G.; Polizzo, S.; Smith, K.; Than, R.; Tuozzolo, J.; Veshcherevich, V.; Wu, Q.; Xiao, B.; Xu, W.; Zaltsman, A.

    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.

  17. Improved temperature regulation of APS linac RF components.

    SciTech Connect

    Dortwegt, R.

    1998-09-21

    The temperature of the APS S-Band linac's high-power rf components is regulated by water from individual closed-loop deionized (DI) water systems. The rf components are all made of oxygen-free high-conductivity copper and respond quickly to temperature changes. The SLED cavities are especially temperature-sensitive and cause beam energy instabilities when the temperature is not well regulated. Temperature regulation better than {+-} 0.1 F is required to achieve good energy stability. Improvements in the closed-loop water systems have enabled them to achieve a regulation of {+-} 0.05 F over long periods. Regulation philosophy and equipment are discussed and numerical results are presented.

  18. RF-windows used at the KEKB linac

    NASA Astrophysics Data System (ADS)

    Michizono, S.; Saito, Y.; Matsumoto, T.; Fukuda, S.; Anami, S.

    2001-01-01

    In the KEKB linac (8 GeV electrons and 3.5 GeV positrons), 58 pulsed klystrons (2856 MHz, 40 MW, 4 μs, 50 pps) are used for electron/positron acceleration. Alumina pill-box windows are installed in the klystrons and waveguides in order to isolate the vacuum from the atmosphere and to pass rf power. Breakdown of alumina ceramics is one of the most serious problems concerning stable operation. A temperature rise (Δ T) on a pill-box housing during rf operation is good for breakdown diagnostics and this has been measured periodically. The measured values are summarized statistically and broken windows are also analyzed.

  19. Superconducting RF Linac Technology for ERL Light Sources

    SciTech Connect

    Tennant, Chris

    2005-08-01

    Energy Recovering Linacs (ERLs) offer an attractive alternative as drivers for light sources as they combine the desirable characteristics of both storage rings (high efficiency) and linear accelerators (superior beam quality). Using superconducting RF technology allows ERLs to operate more efficiently because of the inherent characteristics of SRF linacs, namely that they are high gradient-low impedance structures and their ability to operate in the long pulse or CW regime. We present an overview of the physics challenges encountered in the design and operation of ERL based light sources with particular emphasis on those issues related to SRF technology. These challenges include maximizing a cavity's Qo to increase cryogenic efficiency, maintaining control of the cavity field in the presence of the highest feasible loaded Q and providing adequate damping of the higher-order modes (HOMs). If not sufficiently damped, dipole HOMs can drive the multipass beam breakup (BBU) instability which ERLs are particularly susceptible to. Another challenge involves efficiently extracting the potentially large amounts of HOM power that are generated when a bunch traverses the SRF cavities and which may extend over a high range of frequencies. We present experimental data from the Jefferson Lab FEL Upgrade, a 10 mA ERL light source presently in operation, aimed at addressing some of these issues. We conclude with an outlook towards the future of ERL based light sources.

  20. Sparking limits, cavity loading, and beam breakup instability associated with high-current rf linacs

    SciTech Connect

    Faehl, R.J.; Lemons, D.S.; Thode, L.E.

    1982-01-01

    The limitations on high-current rf linacs due to gap sparking, cavity loading, and the beam breakup instability are studied. It appears possible to achieve cavity accelerating gradients as high as 35 MV/m without sparking. Furthermore, a linear analysis, as well as self-consistent particle simulations of a multipulsed 10 kA beam, indicated that only a negligible small fraction of energy is radiated into nonfundamental cavity modes. Finally, the beam breakup instability is analyzed and found to be able to magnify initial radial perturbations by a factor of no more than about 20 during the beam transit time through a 1 GeV accelerator.

  1. An Overview of the MaRIE X-FEL and Electron Radiography LINAC RF Systems

    SciTech Connect

    Bradley, Joseph Thomas III; Rees, Daniel Earl; Scheinker, Alexander; Sheffield, Richard L.

    2015-05-04

    The purpose of the Matter-Radiation Interactions in Extremes (MaRIE) facility at Los Alamos National Laboratory is to investigate the performance limits of materials in extreme environments. The MaRIE facility will utilize a 12 GeV linac to drive an X-ray Free-Electron Laser (FEL). Most of the same linac will also be used to perform electron radiography. The main linac is driven by two shorter linacs; one short linac optimized for X-FEL pulses and one for electron radiography. The RF systems have historically been the one of the largest single component costs of a linac. We will describe the details of the different types of RF systems required by each part of the linacs. Starting with the High Power RF system, we will present our methodology for the choice of RF system peak power and pulselength with respect to klystron parameters, modulator parameters, performance requirements and relative costs. We will also present an overview of the Low Level RF systems that are proposed for MaRIE and briefly describe their use with some proposed control schemes.

  2. The Boeing 120 MeV RF linac for FEL research

    SciTech Connect

    Adamski, J.L.; Gallagher, W.J.; Kennedy, R.C.; Robinson, B.; Shoffstall, D.R.; Tyson, E.L.; Vetter, A.M.; Yeremian, A.D.

    1985-10-01

    A new electron linac for high power, visible wavelength, free electron laser research is under construction at the Boeing Radiation Laboratory in Seattle. The linac is a five section, traveling wave, L band structure with a specialized ''comb'' pulse format of widely separated high charge micropulses. The paper describes the accelerator design and prototyping of key components of the linac. These include a double subharmonic injector and a long pulse phase and amplitude stabilized RF source which have been tested on Boeing's 20 MeV S band linac.

  3. Multi-cell disk-and-ring tapered structure for compact RF linacs

    NASA Astrophysics Data System (ADS)

    Smirnov, A. V.; Boucher, S.; Kutsaev, S.; Hartzell, J.; Savin, E.

    2016-09-01

    A tubular disk-and-ring, tapered accelerating structure for small electron linacs and MicroLinacs is considered. It consists of metal and dielectric elements inserted into a metallic tube to eliminate multi-cell, multi-step brazing. The structure enables a wide range of phase velocities (including non-relativistic), a wide bandwidth allowing large number of cells (for standing wave mode) or short filling time (for traveling wave mode), combination of compensated and purely π-mode cells, alternative periodic focusing built-in to the RF structure (the disks), and combining of RF and vacuum windows. RF and accelerating performance of such a long structure having up to four dozens cells is analyzed. Some of beam dynamics, thermal, and vacuum aspects of the structure and MicroLinac performance are considered as well.

  4. Experimental investigation of heating phenomena in linac mechanical interfaces due to RF field penetration

    SciTech Connect

    Fazio, M.V.; Reid, D.W.; Potter, J.M.

    1981-01-01

    In a high duty-factor, high-current, drift-tube linear accelerator, a critical interface exists between the drift-tube stem and the tank wall. This interface must provide vacuum integrity and RF continuity, while simultaneously allowing alignment flexibility. Because of past difficulties with RF heating of vacuum bellows and RF joints encountered by others, a paucity of available information, and the high reliability requirement for the Fusion Materials Irradiation Test (FMIT) accelerator, a program was initiated to study the problem. Because RF heating is the common failure mode, an attempt was made to find a correlation between the drift-tube-stem/linac-tank interface geometry and RF field penetration from the tank into the interface region. Experiments were performed at 80 MHz on an RF structure designed to simulate the conditions to which a drift-tube stem and vacuum bellows are exposed in a drift-tube linac. Additional testing was performed on a 367-MHz model of the FMIT prototype drift-tube linac. Experimental results, and a method to predict excessive RF heating, is presented. An experimentally tested solution to the problem is discussed.

  5. Update on RF System Studies and VCX Fast Tuner Work for the RIA Drive Linac

    SciTech Connect

    Rusnak, B; Shen, S

    2003-05-06

    The limited cavity beam loading conditions anticipated for the Rare Isotope Accelerator (RIA) create a situation where microphonic-induced cavity detuning dominates radio frequency (RF) coupling and RF system architecture choices in the linac design process. Where most superconducting electron and proton linacs have beam-loaded bandwidths that are comparable to or greater than typical microphonic detuning bandwidths on the cavities, the beam-loaded bandwidths for many heavy-ion species in the RIA driver linac can be as much as a factor of 10 less than the projected 80-150 Hz microphonic control window for the RF structures along the driver, making RF control problematic. While simply overcoupling the coupler to the cavity can mitigate this problem to some degree, system studies indicate that for the low-{beta} driver linac alone, this approach may cost 50% or more than an RF system employing a voltage controlled reactance (VCX) fast tuner. An update of these system cost studies, along with the status of the VCX work being done at Lawrence Livermore National Lab is presented here.

  6. Use of the delta-t method for setting rf phase and amplitude for the AHF linac

    SciTech Connect

    Swain, G.R.

    1989-01-01

    The delta-t procedure is a time-of-flight method of finding set points for the rf phase and amplitude for each module of a linac. Expected errors for LAMPF afterburner linacs which might be used for an advanced hadron facility (AHF) are calculated. The modified delta-t procedure used on modules 13 through 48 of the present linac appears adequate to set up the proposed AHF linacs. 24 refs., 7 figs., 1 tab.

  7. A photocathode rf gun design for a mm-wave linac-based FEL

    SciTech Connect

    Nassiri, A.; Berenc, T,; Foster, J.; Waldschmidt, G.; Zhou, J.

    1995-07-01

    In recent years, advances in the rf gun technology have made it possible to produce small beam emittances suitable for short period microundulators which take advantage of the low emittance beam to reduce the wavelength of FELs. At the Advanced Photon Source, we are studying the design of a compact 50-MeV superconducting mm-wave linac-based FEL for the production of short wavelengths ({approximately}300 nm) to carry out FEL demonstration experiments. The electron source considered for the linac is a 30- GHz, 3 1/2-cell {pi}-mode photocathode rf gun. For cold model rf measurements a 15-GHz prototype structure was fabricated. Here we report on the design, numerical modelling and the initial cold-model rf measurement results on the 15-GHz prototype structure.

  8. Theory of longitudinal beam halo in RF linacs: II. envelope-particle resonances

    SciTech Connect

    Lund, S.M.; Barnard, J.J.

    1997-05-01

    Using the core/test-particle model described in a companion paper in these proceedings (``Theory of Longitudinal Halo in rf Linacs: I. Core/Test Particle Formulation,`` by J. J. Barnard and S. M. Lund), we analyze longitudinal beam halo produced by resonant self-field interactions in intense, ion-beam rf linacs. It is shown that particles moving in the presence of the space-charge forces of an oscillating, mismatched ellipsoidal beam bunch can be resonantly driven to large longitudinal amplitude. This resonantly produced halo is first analyzed in a limit where it is most simply understood, with particles moving purely longitudinally and with linear rf focusing. Then modifications of the resonance induced by nonlinear rf and transverse-longitudinal coupling are explored.

  9. RF phase stability in the 100-MeV proton linac operation

    NASA Astrophysics Data System (ADS)

    Seol, Kyung-Tae

    2015-02-01

    The 100-MeV proton linac of the Korea multi-purpose accelerator complex (KOMAC) has been operated to provide a proton beam to users. The 100-MeV linac consists of a 3-MeV radio-frequency quadrupole accelerator (RFQ), four 20-MeV drift-tube linac (DTL) tanks, two medium-energy beam-transmitter (MEBT) tanks, and seven 100-MeV DTL tanks. The requirements of the field stability are within ±1% in RF amplitude and ±1 degree in RF phase. The RF phase stability is influenced by a RF reference line, RF transmission lines, and a RF control system. The RF reference signal is chosen to be a 300-MHz local oscillator (LO) signal, and a rigid copper coaxial line with temperature control was installed for an RF reference distribution. A phase stability of ±0.1 degrees was measured under a temperature change of ±0.1 °C. A digital feedback control system with a field-programmable gate-array (FPGA) module was adopted for a high RF stability. The RF phase was maintained within ±0.1 degrees with a dummy cavity and was within ±0.3 degrees at RFQ operation. In the case of the 20-MeV DTL tanks, one klystron drives 4 tanks, and the input phases of 4 tanks were designed to be in phase. The input phases of 4 tanks were fixed within ±1 degree by adjusting a phase shifter in each waveguide.

  10. Characterization of Radiation Induced Current in RF coils of Linac-MR Systems

    NASA Astrophysics Data System (ADS)

    Burke, Benjamin Lester

    by up to 60%. The SNR is improved in the images obtained concurrently with radiation if buildup is applied to the coil. The final part examined the effect of RIC on MR image quality. Imaging experiments were performed on the prototype linac-MR system and the RIC-induced signal-to-noise ratio (SNR) degradation of MR images was quantified. An image post-processing algorithm was proposed which removes some of the RIC-corrupted data from the MR images to recover some of the lost image SNR. The presence of RIC in MR RF coils leads to a loss of SNR which is directly related to the linac dose rate. The RIC related loss in SNR is likely to increase for future commercial systems that are likely to provide larger dose rate than the prototype system (250 cGy/min). Some of this SNR loss can be recovered through the use of a post-processing algorithm which removes the RIC artefact from the image k-space.

  11. The linac and booster RF systems for a dedicated injector for SPEAR

    SciTech Connect

    Weaver, J.N.; Baird, S., Baltay, M.; Borland, M.; Nuhn, H.D.; Safranek, J.; Chavis, C.; Emery, L.; Genin, R.D.; Hettel, R.; Morales, H.; Sebek, J.; Voss, J.; Wang, H.; Wiedemann, H.; Youngmann, B. . Stanford Synchrotron Radiation Lab.); Miller, R.H. )

    1991-05-01

    A 120 MeV, 2856 MHz, TW linac, with a microwave gun, alpha magnet, and chopper, has been built at SSRL as a preinjector for and along with a 3 GeV booster synchrotron ring. The resulting injector will be available on demand to fill SPEAR, which is a storage ring now dedicated to synchrotron light production. The linac sections were purchased from China, the XK-5 klystrons were obtained surplus from SLAC, the modulators are a variation on those at SLAC and were built by SSRL, the alpha magnet and chopper were designed and built at SSRL and the microwave gun was designed and built in collaboration with Varian Associates. The rf system for the booster ring is similar to those at SPEAR and PEP and was built by SSRL. Some of the interesting mechanical and electrical details are discussed and the operating characteristics of the linac and ring rf system are highlighted. 8 refs., 6 figs.

  12. Beam loading compensation of traveling wave linacs through the time dependence of the rf drive

    SciTech Connect

    Towne N.; Rose J.

    2011-09-30

    Beam loading in traveling-wave linear accelerating structures leads to unacceptable spread of particle energies across an extended train of bunched particles due to beam-induced field and dispersion. Methods for modulating the rf power driving linacs are effective at reducing energy spread, but for general linacs do not have a clear analytic foundation. We report here methods for calculating how to modulate the rf drive in arbitrarily nonuniform traveling-wave linacs within the convective-transport (power-diffusion) model that results in no additional energy spread due to beam loading (but not dispersion). Varying group velocity, loss factor, and cell quality factor within a structure, and nonzero particle velocity, are handled.

  13. RF system developments for CW and/or long pulse linacs

    SciTech Connect

    Lynch, M.

    1998-12-31

    High Power Proton Linacs are under development or proposed for development at Los Alamos and elsewhere. By current standards these linacs all require very large amounts of RF power. The Accelerator for Production of Tritium (APT) is a CW accelerator with an output current and energy of 100 mA and 1,700 MeV, respectively. The Spallation Neutron Source (SNS), in its ultimate configuration, is a pulsed accelerator with an average output power of 4 MW of beam. Other accelerators such as those that address transmutation and upgrades to LANSCE have similar requirements. For these high average power applications, the RF systems represent approximately half of the total cost of the linac and are thus key elements in the design and configuration of the accelerator. Los Alamos is fortunate to be actively working on both APT and SNS. For these programs the author is pursuing a number of component developments which are aimed at one or more of the key issues for large RF systems: technical performance, capital cost, reliability, and operating efficiency. This paper briefly describes some of the linac applications and then provides updates on the key RF developments being pursued.

  14. Current status of the superconducting RF linac driver for the JAERI Free Electron Laser Facility

    SciTech Connect

    Minehara, E.J.; Sugimoto, M.; Sawamura, M.

    1995-12-31

    The commissioning of the superconducting rf linac driver for the JAERI free electron laser facility has been successfully performed at 10{approx}20 MeV before the end of the 1994 Japanese fiscal year. The performance obtained during the commissioning and current status of the JAERI FEL program at Tokai will be reported in detail.

  15. RF low-level control for the Linac4 H{sup −} source

    SciTech Connect

    Butterworth, A. Grudiev, A.; Lettry, J.; Paoluzzi, M.; Schmitzer, C.; Nishida, K.

    2015-04-08

    The H{sup −} source for the Linac4 accelerator at CERN uses an RF driven plasma for the production of H{sup −}. The RF is supplied by a 2 MHz RF tube amplifier with a maximum power output of 100 kW and a pulse duration of up to 2 ms. The low-level RF signal generation and measurement system has been developed using standard CERN controls electronics in the VME form factor. The RF frequency and amplitude reference signals are generated using separate arbitrary waveform generator channels. The frequency and amplitude are both freely programmable over the duration of the RF pulse, which allows fine-tuning of the excitation. Measurements of the forward and reverse RF power signals are performed via directional couplers using high-speed digitizers, and permit the estimation of the plasma impedance and deposited power via an equivalent circuit model. The low-level RF hardware and software implementations are described, and experimental results obtained with the Linac4 ion sources in the test stand are presented.

  16. Study of transient self-consistent beam dynamics in RF linacs using a particle tracing code

    NASA Astrophysics Data System (ADS)

    Mytrochenko, V. V.; Opanasenko, A.

    2006-03-01

    The paper describes a simulation technique for study of unsteady self-consistent dynamics of charged particles in RF linacs that consist of cavities and travelling wave sections. The approach proposed is based on unsteady theories of the excitation of cavities and waveguides by a beam of charged particles and RF feeders. The theory of waveguide excitation is extended to the case of spatially inhomogeneous travelling-wave structures. The SUPERFISH code is used to evaluate the characteristics of the axisymmetric travelling-wave sections. The PARMELA code is applied for simulation of particle motion and to obtain data required for solving the equations for excitation of the RF structures by the beam.

  17. Radiation induced currents in MRI RF coils: application to linac/MRI integration

    PubMed Central

    Burke, B; Fallone, B G; Rathee, S

    2010-01-01

    The integration of medical linear accelerators (linac) with magnetic resonance imaging (MRI) systems is advancing the current state of image-guided radiotherapy. The MRI in these integrated units will provide real-time, accurate tumor locations for radiotherapy treatment, thus decreasing geometric margins around tumors and reducing normal tissue damage. In the real-time operation of these integrated systems, the radiofrequency (RF) coils of MRI will be irradiated with radiation pulses from the linac. The effect of pulsed radiation on MRI radio frequency (RF) coils is not known and must be studied. The instantaneous radiation induced current (RIC) in two different MRI RF coils were measured and presented. The frequency spectra of the induced currents were calculated. Some basic characterization of the RIC was also done: isolation of the RF coil component responsible for RIC, dependence of RIC on dose rate, and effect of wax buildup placed on coil on RIC. Both the time and frequency characteristics of the RIC were seen to vary with the MRI RF coil used. The copper windings of the RF coils were isolated as the main source of RIC. A linear dependence on dose rate was seen. The RIC was decreased with wax buildup, suggesting an electronic disequilibrium as the cause of RIC. This study shows a measurable RIC present in MRI RF coils. This unwanted current could be possibly detrimental to the signal to noise ratio in MRI and produce image artifacts. PMID:20071754

  18. X-band RF gun and linac for medical Compton scattering X-ray source

    NASA Astrophysics Data System (ADS)

    Dobashi, Katsuhito; Uesaka, Mitsuru; Fukasawa, Atsushi; Sakamoto, Fumito; Ebina, Futaro; Ogino, Haruyuki; Urakawa, Junji; Higo, Toshiyasu; Akemoto, Mitsuo; Hayano, Hitoshi; Nakagawa, Keiichi

    2004-12-01

    Compton scattering hard X-ray source for 10-80 keV are under construction using the X-band (11.424 GHz) electron linear accelerator and YAG laser at Nuclear Engineering Research laboratory, University of Tokyo. This work is a part of the national project on the development of advanced compact medical accelerators in Japan. National Institute for Radiological Science is the host institute and U.Tokyo and KEK are working for the X-ray source. Main advantage is to produce tunable monochromatic hard (10-80 keV) X-rays with the intensities of 108-1010 photons/s (at several stages) and the table-top size. Second important aspect is to reduce noise radiation at a beam dump by adopting the deceleration of electrons after the Compton scattering. This realizes one beamline of a 3rd generation SR source at small facilities without heavy shielding. The final goal is that the linac and laser are installed on the moving gantry. We have designed the X-band (11.424 GHz) traveling-wave-type linac for the purpose. Numerical consideration by CAIN code and luminosity calculation are performed to estimate the X-ray yield. X-band thermionic-cathode RF-gun and RDS(Round Detuned Structure)-type X-band accelerating structure are applied to generate 50 MeV electron beam with 20 pC microbunches (104) for 1 microsecond RF macro-pulse. The X-ray yield by the electron beam and Q-switch Nd:YAG laser of 2 J/10 ns is 107 photons/RF-pulse (108 photons/sec at 10 pps). We design to adopt a technique of laser circulation to increase the X-ray yield up to 109 photons/pulse (1010 photons/s). 50 MW X-band klystron and compact modulator have been constructed and now under tuning. The construction of the whole system has started. X-ray generation and medical application will be performed in the early next year.

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

    NASA Astrophysics Data System (ADS)

    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.

  20. Design and fabrication of the high-power RF transmission line into the PEFP linac tunnel

    NASA Astrophysics Data System (ADS)

    Seol, Kyung-Tae; Kwon, Hyeok-Jung; Kim, Han-Sung; Cho, Yong-Sub

    2012-07-01

    The 100-MeV proton linear accelerator (linac) for the Proton Engineering Frontier Project (PEFP) has been developed and will be installed at the Gyeong-ju site. For the linac, a total of 11 sets of RF systems are required, and the waveguide layout was fixed to install high-power RF (HPRF) systems. One of the important interfaces with the building construction is the high-power radio-frequency (HPRF) transmission line embedded in the tunnel, which is used to transmit 1-MW RF power to each cavity in the tunnel. The waveguide section penetrating into the linac tunnel was designed with a bending structure for radiation shielding, and the dependence of its voltage standing-wave ratio (VSWR) on the chamfer length of the bending was calculated. The HPRF transmission line was fabricated into a piece of waveguide to prevent moisture and any foreign debris inside the 2.5-m thick concrete block. Air leakage was checked with a pressure of 0.25 psig of nitrogen gas, and a maximum VSWR of 1.196 was obtained by measuring the vector reflection coefficients with the quarter-wave transmission section. In this paper, the design and the fabrication of the HPRF transmission line into the PEFP linac tunnel are presented.

  1. Engineering development of superconducting RF linac for high-power applications

    SciTech Connect

    Dominic Chan, K.C.; Rusnak, B.; Gentzlinger, R.C.; Campbell, B.M.; Kelley, J.P.; Safa, H.

    1998-12-31

    High-power proton linacs are a promising source of neutrons for material processing and research applications. Superconducting radiofrequency (SCRF) Rf linac technology is preferred for such applications because of power efficiency. A multi-year engineering development program is underway at Los Alamos National Laboratory to demonstrate the required SCRF technology. The program consists of development of SC cavities, power couplers, and cryomodule integration. Prototypes will be built and operated to obtain performance and integration information, and for design improvement. This paper describes the scope and present status of the development program.

  2. New high power 200 MHz RF system for the LANSCE drift tube linac

    SciTech Connect

    Lyles, J.; Friedrichs, C.; Lynch, M.

    1998-12-31

    The Los Alamos Neutron Science Center (LANSCE) linac provides an 800 MeV direct H{sup +} proton beam, and injects H{sup {minus}} to the upgraded proton storage ring for charge accumulation for the Short Pulse Spallation Source. Accelerating these interlaced beams requires high average power from the 201.25 MHz drift tube linac (DTL) RF system. Three power amplifiers have operated at up to three Megawatts with 12% duty factor. The total number of electron power tubes in the RF amplifiers and their modulators has been reduced from fifty-two to twenty-four. The plant continues to utilize the original design of a tetrode driving a super power triode. Further increases in the linac duty factor are limited, in part, by the maximum dissipation ratings of the triodes. A description of the system modifications proposed to overcome these limitations includes new power amplifiers using low-level RF modulation for tank field control. The first high power Diacrode{reg_sign} is being delivered and a new amplifier cavity is being designed. With only eight power tubes, the new system will deliver both peak power and high duty factor, with lower mains power and cooling requirements. The remaining components needed for the new RF system will be discussed.

  3. The RF power system for the SNS linac

    SciTech Connect

    Tallerico, P.J.; Reass, W.A.

    1998-12-31

    The initial goal of the SNS project is to produce a 1 MW average beam of protons with short pulse lengths onto a neutron-producing target. The objective of the SNS RF system is to generate 117 MW peak of pulsed 805 MHz microwave power with an accelerated beam pulse length of 1.04 ms at a 60 Hz repetition rate. The power system must be upgradeable in peak power to deliver 2 MW average power to the neutron target. The RF system also requires about 3 MW peak of RF power at 402.5 MHz, but that system is not discussed here. The design challenge is to produce an RF system at minimum cost, that is very reliable and economical to operate. The combination of long pulses and high repetition rates make conventional solutions, such as the pulse transformer and transmission line method, very expensive. The klystron, with a modulating anode, and 1.5 MW of peak output power is the baseline RF amplifier, an 56 are required in the baseline design. The authors discuss four power system configurations that are the candidates for the design. The baseline design is a floating-deck modulating anode system. A second power system being investigated is the fast-pulsed power supply, that can be turned on and off with a rise time of under 0.1 ms. This could eliminate the need for a modulator, and drastically reduce the energy storage requirements. A third idea is to use a pulse transformer with a series IGBT switch and a bouncer circuit on the primary side, as was done for the TESLA modulator. A fourth method is to use a series IGBT switch at high voltage, and not use a pulse transformer. The authors discuss the advantages and problems of these four types of power systems, but they emphasize the first two.

  4. Linac Coherent Light Source Undulator RF BPM System

    SciTech Connect

    Lill, R.M.; Morrison, L.H.; Waldschmidt, G.J.; Walters, D.R.; Johnson, R.; Li, Z.; Smith, S.; Straumann, T.; /SLAC

    2007-04-17

    The Linac Coherent Light Source (LCLS) will be the world's first x-ray free-electron laser (FEL) when it becomes operational in 2009. The LCLS is currently in the construction phase. The beam position monitor (BPM) system planned for the LCLS undulator will incorporate a high-resolution X-band cavity BPM system described in this paper. The BPM system will provide high-resolution measurements of the electron beam trajectory on a pulse-to-pulse basis and over many shots. The X-band cavity BPM size, simple fabrication, and high resolution make it an ideal choice for LCLS beam position detection. We will discuss the system specifications, design, and prototype test results.

  5. A compact RF power coupler for the NLC linac

    SciTech Connect

    Bowden, G.B.

    2000-03-01

    A high power RF coupler connecting WR90 rectangular waveguide to the disc loaded waveguide accelerating structure of NLC is described. The coupler design is symmetric and free of beam deflecting field components. It makes an efficient electrical match between the rectangular waveguide power feed and the accelerator structure while keeping electrical surface field enhancement low. Electrical and mechanical design of the coupler are presented as well as quantitative comparisons between numerical simulation and low power cold test models.

  6. Status of RF system for the JAERI energy-recovery linac FEL

    NASA Astrophysics Data System (ADS)

    Sawamura, Masaru; Nagai, Ryoji

    2006-02-01

    The two types of the RF sources are used for the JAERI ERL-FEL. One is an all-solid state amplifier and the other is an inductive output tube (IOT). There are advantages of little failure and wide bandwidth for the all-solid state amplifier, low cost and high efficiency for IOT. The property of low cost with the IOT is suitable for a large machine like an energy recovery linac (ERL).

  7. RF power upgrade at the superconducting 1.3 GHz CW LINAC "ELBE" with solid state amplifiers

    NASA Astrophysics Data System (ADS)

    Büttig, Hartmut; Arnold, A.; Büchner, A.; Justus, M.; Kuntsch, M.; Lehnert, U.; Michel, P.; Schurig, R.; Staats, G.; Teichert, J.

    2013-03-01

    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.

  8. A CW normal-conductive RF gun for free electron laser and energy recovery linac applications

    SciTech Connect

    Baptiste, Kenneth; Corlett, John; Kwiatkowski, Slawomir; Lidia, Steven; Qiang, Ji; Sannibale, Fernando; Sonnad, Kiran; Staples, John; Virostek, Steven; Wells, Russell

    2008-10-08

    Currently proposed energy recovery linac and high average power free electron laser projects require electron beam sources that can generate up to {approx} 1 nC bunch charges with less than 1 mmmrad normalized emittance at high repetition rates (greater than {approx} 1 MHz). Proposed sources are based around either high voltage DC or microwave RF guns, each with its particular set of technological limits and system complications. We propose an approach for a gun fully based on mature RF and mechanical technology that greatly diminishes many of such complications. The concepts for such a source as well as the present RF and mechanical design are described. Simulations that demonstrate the beam quality preservation and transport capability of an injector scheme based on such a gun are also presented.

  9. Status of the low-energy Linac 200-MHz rf stations

    SciTech Connect

    Charles W. Schmidt et al.

    2002-03-21

    This report describes the present status of the five low-energy Linac 200-MHz RF stations with regard to availability and reliability of major components. An attempt has been made to describe possible solutions (or non-solutions) and to indicate some of the complexity and interplay between those solutions. For the problem at hand, the discontinuance of this one particular tube, an acceptable solution plan must be identified and designed in detail in the near future. As explained herein, the time scale for implementing a solution is five years; beyond that time there is considerable risk of finding ourselves with a non-maintainable Linac and no High Energy Physics program at Fermilab.

  10. An Rf-gun-driven recirculated linac as injector and FEL driver.

    SciTech Connect

    Andersson, A.; Biedron, S.; Eriksson, M.; Freund, H.; Werin, S.

    1999-08-23

    A new pre-injector for the MAX-Laboratory is under design and construction. A thermionic rf gun, designed to operate at medium currents with low back bombardment power, is under construction. The gun will, via a magnetic compressor and energy filter, feed a recirculated linac consisting of two SLED-equipped structures giving 125 MeV each. The first will be delivered in 1999. The system is aimed as a pre-injector for the existing storage rings at MAX-Lab, but will also open up possibilities for a SASE FEL in the UV reaching above 100 MW below 100 run.

  11. Status of the RF-driven H- ion source for J-PARC linac

    NASA Astrophysics Data System (ADS)

    Oguri, H.; Ohkoshi, K.; Ikegami, K.; Takagi, A.; Asano, H.; Ueno, A.; Shibata, T.

    2016-02-01

    For the upgrade of the Japan Proton Accelerator Research Complex linac beam current, a cesiated RF-driven negative hydrogen ion source was installed during the 2014 summer shutdown period, with subsequent operations commencing on September 29, 2014. The ion source has been successfully operating with a beam current and duty factor of 33 mA and 1.25% (500 μs and 25 Hz), respectively. The result of recent beam operation has demonstrated that the ion source is capable of continuous operation for approximately 1100 h. The spark rate at the beam extractor was observed to be at a frequency of less than once a day, which is an acceptable level for user operation. Although an antenna failure occurred during operation on October 26, 2014, no subsequent serious issues have occurred since then.

  12. Status of the RF-driven H⁻ ion source for J-PARC linac.

    PubMed

    Oguri, H; Ohkoshi, K; Ikegami, K; Takagi, A; Asano, H; Ueno, A; Shibata, T

    2016-02-01

    For the upgrade of the Japan Proton Accelerator Research Complex linac beam current, a cesiated RF-driven negative hydrogen ion source was installed during the 2014 summer shutdown period, with subsequent operations commencing on September 29, 2014. The ion source has been successfully operating with a beam current and duty factor of 33 mA and 1.25% (500 μs and 25 Hz), respectively. The result of recent beam operation has demonstrated that the ion source is capable of continuous operation for approximately 1100 h. The spark rate at the beam extractor was observed to be at a frequency of less than once a day, which is an acceptable level for user operation. Although an antenna failure occurred during operation on October 26, 2014, no subsequent serious issues have occurred since then. PMID:26932020

  13. Low level rf system for the European Spallation Source's Bilbao linac

    NASA Astrophysics Data System (ADS)

    Hassanzadegan, Hooman; Garmendia, Nagore; Etxebarria, Victor; Bermejo, F. Javier

    2011-05-01

    Design and some performance results of the pulsed digital low level radio frequency (LLRF) for the radio frequency quadrupole (RFQ) systems of Rutherford Appleton Laboratory-front end test stand and the future European Spallation Source Bilbao linac are presented. For rf field regulation, the design is based on direct rf-to-baseband conversion using an analog in-phase quadrature (IQ) demodulator, high-speed sampling of the I/Q components, baseband signal processing in a field-programmable gate array (FPGA), conversion to analog, and IQ modulation. This concept leads to a simple and versatile LLRF system which can be used for a large variety of rf frequencies and virtually any LLRF application including cw, ramping, and pulsed. In order to improve the accuracy of the probe voltage measurement, errors associated with the use of analog IQ demodulators have been identified and corrected by FPGA algorithms and proper setting of the feedback loop parameters. Furthermore, a baseband-equivalent model for the rf plant is developed in MATLAB-Simulink to study the RFQ transient response under beam loading in the presence of phase and delay errors. The effect of the unwanted resonant modes on the feedback loop stability and the LLRF considerations to avoid such instabilities are discussed and compared to some other machines such as the ILC and the European free electron laser . The practical results obtained from tests with a mock-up cavity and an RFQ cold model verify that amplitude and phase stabilities down to a fraction of one percent and one degree and phase margins larger than ±50° can be achieved with this method preserving the linearity and bandwidth of the feedback loops.

  14. Improvements of Low Level RF Control Systems for J-PARC LINAC 400-MeV Upgrade

    NASA Astrophysics Data System (ADS)

    Fang, Z.; Futatsukawa, K.; Fukui, Y.; Kobayashi, T.; Michizono, S.; Sato, F.; Shinozaki, S.; Chishiro, E.

    The low level RF (LLRF) control systems have been successfully improved for the J-PARC LINAC upgrade. After the installation of 972-MHz high-β acceleration section behind the 324-MHz low-β section beginning in the summer of 2013, the proton beam was successfully accelerated to 400 MeV in January 2014. Many improvements in the LLRF control systems have been carried out to facilitate the operation of the J-PARC LINAC at 400 MeV. The reference 12-MHz signal delay settings for the feedback control systems have been optimized using 12-MHz delay modules. The stability performances of the 972-MHz RF&CLK (Clock) and Mixer&IQ (Mixer & IQ-modulator) boards have been improved using temperature-compensation techniques. By improving the hardware of the feedback control systems, very good stability of the RF systems has been achieved.

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

    SciTech Connect

    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.

  16. A compact high-gradient 25 MeV 17 GHz RF linac for free-electron laser research

    SciTech Connect

    Danly, B.G.; Chen, S.C.; Kreischer, K.E.

    1995-12-31

    A new compact high-gradient (60 MeV/m) high-frequency (17.136 GHz) RF linac is presently under construction by Haimson Research Corp. (HRC) for installation at the MIT Plasma Fusion Center in the High-Gradient Accelerator and High Power Microwave Laboratory. This accelerator will utilize an existing traveling-wave relativistic klystron (TWRK) which is now operation at MIT with 25 MW power, 67 dB gain, and 52% efficiency at 17.136 GHz.

  17. Theory of longitudinal beam halo in RF linacs: I. core/test-particle formulation

    SciTech Connect

    Barnard, J.J.; Lund, S.M.

    1997-05-01

    For intense beams, the analysis of tenuous halo components of the particle distribution that surround the main core of the distribution can be challenging. So-called core/test particle models in which a test particle is evolved in the applied and space-charge forces of the beam core have been instrumental in understanding the structure and extent of transverse beam halo produced by resonant particle interactions with the oscillating space-charge forces of a mismatched beam core. Here we present a core/test particle model developed for the analysis of longitudinal beam halo in intense, ion-beam rf linacs. Equations of motion are derived for a test particle moving interior to, and exterior to, a uniform density ellipsoidal beam bunch. Coupled transverse-longitudinal mismatch modes of the ellipsoidal beam envelope are analyzed. Typical parameters suggest the possibility of a low-order resonant interaction between longitudinal particle oscillations and a low-frequency envelope mode. Properties of this resonance are in an accompanying paper by the authors in these proceedings.

  18. Summary of Linac Group discussions

    SciTech Connect

    Schaffer, G.

    1989-01-01

    This paper discusses upgrading of the LAMPF I linac. Particular topics discussed are: sources of and cures for linac beam halos, ion source, RFQ, chopper and drift-tube linac, cavity-coupled linac, superconducting linac structure, new rf power sources, EHF linac design, and cost projections. (LSP)

  19. Operational experience with a free-electron laser driven by an rf photoinjector linac

    SciTech Connect

    O`Shea, P.G.

    1993-10-01

    For a number of years Los Alamos National Laboratory has been developing photocathode sources of high-brightness electron beams for FEL applications. The APEX FEL, which has been operational for over two years, was the first FEL to use a custom designed rf photoinjector as its electron source. The system consists of a 1.3 GHz, 6 MeV photoinjector with a multi-alkali photocathode illuminated by a frequency doubled ND:YLF drive-laser, followed by three separately powered accelerating structures that give a final electron energy of 40-MeV. The FEL has operated as an oscillator with either a permanent magnet or pulsed electromagnetic wigglers. Originally the FEL was designed to operate at a wavelengths near 3{mu}m, however the electron beam emittance and brightness are sufficient for harmonic lasing at much shorter wavelengths. We have demonstrated the tunability of the device from 0.37 to 11 {mu}m.

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

    SciTech Connect

    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.

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

    SciTech Connect

    Galambos, J.; Garoby, R.; 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.

  2. A method for measuring dark current electron beams in an rf linac

    SciTech Connect

    Maruyama, X.K.; Fasanello, T.; Rietdyk, H.; Piestrup, M.A.; Rule, D.W.; Fiorito, R.B.

    1993-12-31

    X-ray fluorescence from thin foils inserted into the NPS linac has been used to measure the integrated electron beam intensity when the accelerator is operating with dark current. The measured x-ray flux, the known inner shell ionization cross sections and radiative transition probabilities are used to obtain measurements of dark currents of the order of 10{sup -14} amperes. The same arrangement allows continuous, in-situ energy calibration of our SiLi detector in the electromagnetic noise environment of the linac. This technique was orginally developed to perform absolute production efficiency measurements of parametric x-ray generation in the 5-50 keV range.

  3. 500 MW X-Band RF System of a 0.25 GeV Electron LINAC for Advanced Compton Scattering Source Application

    SciTech Connect

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

    2012-07-03

    A Mono-Energetic Gamma-Ray (MEGa-Ray) Compton scattering light source is being developed at LLNL in collaboration with the SLAC National Accelerator Laboratory. The electron beam for the Compton scattering interaction will be generated by a X-band RF gun and a X-band LINAC at the frequency of 11.424 GHz. High power RF in excess of 500 MW is needed to accelerate the electrons to energy of 250 MeV or greater for the interaction. Two high power klystron amplifiers, each capable of generating 50 MW, 1.5 msec pulses, will be the main high power RF sources for the system. These klystrons will be powered by state of the art solid-state high voltage modulators. A RF pulse compressor, similar to the SLED II pulse compressor, will compress the klystron output pulse with a power gain factor of five. For compactness consideration, we are looking at a folded waveguide setup. This will give us 500 MW at output of the compressor. The compressed pulse will then be distributed to the RF gun and to six traveling wave accelerator sections. Phase and amplitude control are located at the RF gun input and additional control points along the LINAC to allow for parameter control during operation. This high power RF system is being designed and constructed. In this paper, we will present the design, layout, and status of this RF system.

  4. 500 MW X-BAND RF SYSTEM OF A 0.25 GEV ELECTRON LINAC FOR ADVANCED COMPTON SCATTERING SOURCE APPLICATION

    SciTech Connect

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

    2010-05-12

    A Mono-Energetic Gamma-Ray (MEGa-Ray) Compton scattering light source is being developed at LLNL in collaboration with SLAC National Accelerator Laboratory. The electron beam for the Compton scattering interaction will be generated by a X-band RF gun and a X-band LINAC at the frequency of 11.424 GHz. High power RF in excess of 500 MW is needed to accelerate the electrons to energy of 250 MeV or greater for the interaction. Two high power klystron amplifiers, each capable of generating 50 MW, 1.5 msec pulses, will be the main high power RF sources for the system. These klystrons will be powered by state of the art solid-state high voltage modulators. A RF pulse compressor, similar to the SLED II pulse compressor, will compress the klystron output pulse with a power gain factor of five. For compactness consideration, we are looking at a folded waveguide setup. This will give us 500 MW at output of the compressor. The compressed pulse will then be distributed to the RF gun and to six traveling wave accelerator sections. Phase and amplitude control are located at the RF gun input and additional control points along the LINAC to allow for parameter control during operation. This high power RF system is being designed and constructed. In this paper, we will present the design, layout, and status of this RF system.

  5. Overview of superconducting RF technology and its application to high-current linacs

    SciTech Connect

    Delayen, J.R.; Bohn, C.L.

    1994-08-01

    Superconducting linacs may be a viable option for high-current applications such as copious neutron production like that needed for transmutation of radioactive waste. These linacs must run reliably for many years and allow easy routine maintenance. superconducting cavities operate efficiently with high cw gradients, properties which help to reduce operating and capital costs. However, cost effectiveness is not the sole consideration in these applications. For example, beam impingement must be essentially eliminated to prevent unsafe radioactivation of the accelerating structures, and thus large apertures are needed through which to pass the beam. Because of their high efficiency, superconducting cavities can be designed with very large bore apertures, thereby reducing the effect of beam impingement.

  6. R & D on Very-High-Current Superconducting Proton Linac, Final Report

    SciTech Connect

    Ben-Zvi, Ilan

    2013-03-31

    The aim of this R&D project was to develop a superconducting cavity for a very-­ high-current proton accelerator. The particular application motivating the proposal was a LHC upgrade called the Superconducting Proton Linac, or SPL. Under the grant awarded to Stony Brook University the cavity was designed, a prototype copper cavity, followed by the niobium cavity, were built. A new set of HOM dampers was developed. The cavity has outstanding RF performance parameters – low surface fields, low power loss and all HOMs are fully damped. In fact, it is a “universal cavity” in the sense that it is suited for the acceleration of high-­current protons and well as high current electrons. Its damping of HOM modes is so good that it can see service in a multi-pass linac or an Energy Recovery Linac in addition to the easier service in a single-pass linac. Extensive measurements were made on the cavities and couplers, with the exception of the cold test of the niobium cavity. At the time of this report the cavity has been chemically processed and is ready for vertical testing which will be carried out shortly.

  7. Ion Solid Interaction And Surface Modification At RF Breakdown In High-Gradient Linacs

    NASA Astrophysics Data System (ADS)

    Insepov, Zeke; Norem, Jim; Veitzer, Seth

    2011-06-01

    Ion solid interactions have been shown to be an important new mechanism of unipolar arc formation in high-gradient rf linear accelerators through surface self-sputtering by plasma ions, in addition to an intense surface field evaporation. We believe a non-Debye plasma is formed in close vicinity to the surface and strongly affects surface atomic migration via intense bombardment by ions, strong electric field, and high surface temperature. Scanning electron microscope studies of copper surface of an rf cavity were conducted that show craters, arc pits, and both irregular and regular ripple structures with a characteristic length of 2 microns on the surface. Strong field enhancements are characteristic of the edges, corners, and crack systems at surfaces subjected to rf breakdown.

  8. Stability evaluation of femtosecond S-band linac with photocathode RF gun

    NASA Astrophysics Data System (ADS)

    Uesaka, Mitsuru; Watanabe, Takahiro; Kobayashi, Tetsuya; Ueda, Toru; Yoshii, Koji; Kinoshita, Kenichi; Hafz, Nasr; Okuda, Hiroyuki; Hemker, Roy G.; Nakajima, Kazuhisa

    2001-08-01

    Femtosecond S-band linac with the BNL/GUN IV of Nuclear Engineering Research Laboratory, University of Tokyo, has recorded 240fs(FWHM), 6 pai mm. mrad(rms), 350pC/bunch. Maximum charge per bunch at the exit of the injector and QE were 7nC and 1.5×10-4, respectively. After the cathode damage was found, re-measured emittance was 20 pai mm. mrad. Timing jitter between the femtosecond electron bunch and the drive laser for the injector was 330fs for the minutes and 1.9ps for hours. Detailed of the system are described, including the electron bunch diagnosis system. Further, the plasma gun work to produce 10fs, 20 MeV electron single bunch without any timing jitter is also mentioned. Those date and information give important mile stones for development of future SASE-FEL including LCLS.

  9. Deflecting RF cavity design for a recirculating linac based facility for ultrafast X-ray science (LUX)

    SciTech Connect

    Li, Derun; Corlett, J.N.

    2003-05-01

    We report on superconducting deflecting RF cavity designs for a Recirculating Linac Based Facility for Ultrafast X-ray Science (LUX) at Lawrence Berkeley National Laboratory. The deflecting cavities operate in the lowest dipole mode and are required to produce a temporal correlation within flat electron bunches, as needed for x-ray compression in crystal optics. Deflecting voltage of up to 8.5-MV is required at 3.9-GHz. We present a 7-cell cavity design in this paper. Seven such cavities are required to generate the 8.5 MV deflecting voltage. Longitudinal and transverse impedance from LOM (lower order mode) and HOM (higher order mode) are simulated using the MAFIA code. Short-range and long-range wakefield excited through these impedances are calculated. Beam loading effects of the deflecting mode and LOM modes are estimated. Q values of the LOM monopole modes in the cavity may need to be damped to be below 10{sup 4}-10{sup 5} levels in order to maintain the required energy spread.

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

    SciTech Connect

    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.

  11. The Muon LINAC for the International Design Study of the Neutrino Factory

    SciTech Connect

    A. Kurup, C. Bontoiu, Morteza Aslaninejad, J. Pozimski, A. Bogacz, V.S. Morozov, Y.R. Roblin, K.B. Beard

    2011-09-01

    The first stage of muon acceleration in the Neutrino Factory utilises a superconducting linac to accelerate muons from 244 MeV to 900 MeV. The linac was split into three types of cryomodules with decreasing magnetic fields and increasing amounts of RF voltage but with the design of the superconducting solenoid and RF cavities being the same for all cryomodules. The current status of the muon linac for the International Design Study for the Neutrino Factory will be presented including a final lattice design of the linac and tracking simulations.

  12. Ultrafast harmonic rf kicker design and beam dynamics analysis for an energy recovery linac based electron circulator cooler ring

    DOE PAGESBeta

    Huang, Yulu; Wang, Haipeng; Rimmer, Robert A.; Wang, Shaoheng; Guo, Jiquan

    2016-08-01

    An ultrafast kicker system is being developed for the energy recovery linac (ERL) based electron circulator cooler ring (CCR) in the proposed Jefferson Lab Electron Ion Collider (JLEIC, previously named MEIC). In the CCR, the injected electron bunches can be recirculated while performing ion cooling for 10–30 turns before the extraction, thus reducing the recirculation beam current in the ERL to 1/10–1/30 (150mA–50 mA) of the cooling beam current (up to 1.5 A). Assuming a bunch repetition rate of 476.3 MHz and a recirculating factor of 10 in the CCR, the kicker is required to operate at a pulse repetitionmore » rate of 47.63 MHz with pulse width of around 2 ns, so that only every 10th bunch in the CCR will experience a transverse kick while the rest of the bunches will not be disturbed. Such a kicker pulse can be synthesized by ten harmonic modes of the 47.63 MHz kicker pulse repetition frequency, using up to four quarter wavelength resonator (QWR) based deflecting cavities. In this paper, several methods to synthesize such a kicker waveform will be discussed and a comparison of their beam dynamics performance is made using ELEGANT. Four QWR cavities are envisaged with high transverse shunt impedance requiring less than 100 W of total rf power for a Flat-Top kick pulse. Multipole fields due to the asymmetry of this type of cavity are analyzed. The transverse emittance growth due to the sextupole component is simulated in ELEGANT. In conclusion, off-axis injection and extraction issues and beam optics using a multicavity kick-drift scheme will also be discussed.« less

  13. An RF bunch length monitor for the SLC final focus

    SciTech Connect

    Zimmermann, F.; Yocky, G.; Whittum, D.

    1997-05-01

    In preparation for the 1997 SLC run, a novel RF bunch-length monitor has been installed in the SLC South Final Focus. The monitor consists of a ceramic gap in the beam pipe, a 160-ft long X-band waveguide (WR90), and a set of dividers, tapers and microwave detectors. Electromagnetic fields radiated through the ceramic gap excite modes in the nearby open-ended X-band waveguide, which transmits the beam-induced signal to a radiation-free shack outside of the beamline vault. There, a combination of power dividers, tapers, waveguides, and crystal detectors is used to measure the signal power in 4 separate frequency channels between 7 and 110 GHz. For typical rms bunch lengths of 0.5-2 mm in the SLC, the bunch frequency spectrum can extend up to 100 GHz. In this paper, the authors present the overall monitor layout, describe MAFIA calculations of the signal coupled into the waveguide based on a detailed model of the complex beam-pipe geometry, estimate the final power level at the RF conversion points, and report the measured transmission properties of the installed waveguide system.

  14. Solenoid-based focusing in a proton linac

    SciTech Connect

    Terechkine, I; DiMarco, J.; Schappert, W.; Sergatskov, d.; Tartaglia, M.; /Fermilab

    2010-09-01

    Development of solenoid-based focusing lenses for the transport channel of an R&D linac front end at FNAL (HINS linac) is in its final stage. Superconducting lenses for the room temperature RF section of the linac are assembled into individual cryostats and certified using a dedicated test stand. During this certification process, the optical axis of each lens relative to the cryogenic vessel is found in the warm and cold state. Lenses for the superconducting RF sections are ready for production, and development of a cryomodule (which contains multiple superconducting lenses and RF cavities) is in progress. Studies have been conducted to measure fringe magnetic field of a lens in the cryomodule, to investigate a laser-based method of alignment, and to evaluate the extent of beam quality degradation due to imperfections in lens construction and alignment. This report presents some results of these studies.

  15. Electrodeless lighting RF power source development. Final report

    SciTech Connect

    1996-08-30

    An efficient, solid state RF power source has been developed on this NICE project for exciting low power electrodeless lamp bulbs. This project takes full advantage of concurrent advances in electrodeless lamp technology. Electrodeless lamp lighting systems utilizing the sulfur based bulb type developed by Fusion Lighting, Inc., is an emerging technology which is based on generating light in a confined plasma created and sustained by RF excitation. The bulb for such a lamp is filled with a particular element and inert gas at low pressure when cold. RF power from the RF source creates a plasma within the bulb which reaches temperatures approaching those of high pressure discharge lamp plasmas. At these temperatures the plasma radiates substantial visible light with a spectrum similar to sunlight.

  16. Electron bunch energy and phase feed-forward stabilization system for the Mark V RF-linac free-electron laser

    NASA Astrophysics Data System (ADS)

    Hadmack, M. R.; Jacobson, B. T.; Kowalczyk, J. M. D.; Lienert, B. R.; Madey, J. M. J.; Szarmes, E. B.

    2013-06-01

    An amplitude and phase compensation system has been developed and tested at the University of Hawai`i for the optimization of the RF drive system to the Mark V free-electron laser. Temporal uniformity of the RF drive is essential to the generation of an electron beam suitable for optimal free-electron laser performance and the operation of an inverse Compton scattering x-ray source. The design of the RF measurement and compensation system is described in detail and the results of RF phase compensation are presented. Performance of the free-electron laser was evaluated by comparing the measured effects of phase compensation with the results of a computer simulation. Finally, preliminary results are presented for the effects of amplitude compensation on the performance of the complete system.

  17. LINACS FOR FUTURE MUON FACILITIES

    SciTech Connect

    Slawomir Bogacz, Rolland Johnson

    2008-10-01

    Future Muon Colliders (MC) and Neutrino Factories (NF) based on muon storage rings will require innovative linacs to: produce the muons, cool them, compress longi-tudinally and ‘shape’ them into a beam and finally to rap-idly accelerate them to multi-GeV (NF) and TeV (MC) energies. Each of these four linac applications has new requirements and opportunities that follow from the na-ture of the muon in that it has a short lifetime (τ = 2.2 μsec) in its own rest frame, it is produced in a tertiary process into a large emittance, and its electron, photon, and neutrino decay products can be more than an annoy-ance. As an example, for optimum performance, the linac repetition rates should scale inversely with the laboratory lifetime of the muon in its storage ring, something as high as 1 kHz for a 40 GeV Neutrino Factory or as low as 20 Hz for a 5 TeV Muon Collider. A superconducting 8 GeV Linac capable of CW operation is being studied as a ver-satile option for muon production [1] for colliders, facto-ries, and muon beams for diverse purposes. A linac filled with high pressure hydrogen gas and imbedded in strong magnetic fields has been proposed to rapidly cool muon beams [2]. Recirculating Linear Accelerators (RLA) are possible because muons do not generate significant syn-chrotron radiation even at extremely high energy and in strong magnetic fields. We will describe the present status of linacs for muon applications; in particular the longitu-dinal bunch compression in a single pass linac and multi-pass acceleration in the RLA, especially the optics and technical requirements for RLA designs, using supercon-ducting RF cavities capable of simultaneous acceleration of both μ+ and μ- species, with pulsed linac quadrupoles to allow the maximum number of passes. The design will include the optics for the multi-pass linac and droplet-shaped return arcs.

  18. High pulse power rf sources for linear colliders

    SciTech Connect

    Wilson, P.B.

    1983-09-01

    RF sources with high peak power output and relatively short pulse lengths will be required for future high gradient e/sup +/e/sup -/ linear colliders. The required peak power and pulse length depend on the operating frequency, energy gradient and geometry of the collider linac structure. The frequency and gradient are in turn constrained by various parameters which depend on the beam-beam collision dynamics, and on the total ac wall-plug power that has been committed to the linac rf system. Various rf sources which might meet these requirements are reviewed. Existing source types (e.g., klystrons, gyrotrons) and sources which show future promise based on experimental prototypes are first considered. Finally, several proposals for high peak power rf sources based on unconventional concepts are discussed. These are an FEL source (two beam accelerator), rf energy storage cavities with switching, and a photocathode device which produces an rf current by direct emission modulation of the cathode.

  19. High frequency CARM driver for rf linacs. Final report, September 15, 1989--March 15, 1993

    SciTech Connect

    Danly, B.G.

    1993-09-23

    This CARM program has successfully demonstrated the first ever long-pulse CARM oscillator operation; these results demonstrate the potential of CARMs as an alternative source of millimeter waves to the gyrotron for ECRH plasma heating. The result of 1.8 MW at 27.8 GHz and 0.5 {mu}s pulse width in the TE{sub 11} mode represent a clear demonstration of the capabilities of the CARM oscillator for the production of high powers with large frequency upshift. It is hoped that this successful proof-of-principle demonstration.will lead to further development of the CARM as an ECRH source by the DOE Office of Fusion Energy, Development and Technology Division. This success is a direct outcome of this support of the Advanced Energy Projects Office of DOE in the form of this program. The CARM amplifier component of the program, although unsuccessful at obtaining CARM amplifier operation at 17 GHz, has succeeded by furthering the understanding of the limitations and difficulties that lie ahead for continued CARM amplifier development. The amplifier component of the program has successfully demonstrated a high power second and third harmonic gyro-TWT amplifier. Up to 5 MW of power at 17.1 GHz and >50dB gain have been obtained. These results should be viewed as an important contribution of this program to the development of viable microwave sources for powering the next linear collider. Indeed, the present gyro-amplifier, which resulted from this program, is presently being used in ongoing high-gradient accelerator research at MIT under a DOE High Energy Physics grant. As a result of both the oscillator and amplifier advances made during this program, the CARM and harmonic gyro-TWT have reached a significantly more mature level; their future role in specific applications of benefit to DOEs OFE and HEP offices may now be pursued.

  20. The Linac Cooherent Light Source (LCLS) Accelerator

    SciTech Connect

    Wu, Juhao; Emma, P.; /SLAC

    2007-03-21

    The Linac Coherent Light Source (LCLS) is a SASE x-ray Free-Electron Laser (FEL) based on the final kilometer of the Stanford Linear Accelerator. Such an FEL requires a high energy, high brightness electron beam to drive the FEL instability to saturation. When fed by an RF-photocathode gun, and modified to include two bunch compressor chicanes, the SLAC linac will provide such a high quality beam at 14 GeV and 1-{micro}m normalized emittance. In this paper, we report on recent linac studies, including beam stability and tolerances, longitudinal and transverse feedback systems, conventional and time-resolved diagnostics, and beam collimation systems. Construction and installation of the injector through first bunch compressor will be completed by December 2006, and electron commissioning is scheduled to begin in January of 2007.

  1. Final Report for "Design calculations for high-space-charge beam-to-RF conversion".

    SciTech Connect

    David N Smithe

    2008-10-17

    Accelerator facility upgrades, new accelerator applications, and future design efforts are leading to novel klystron and IOT device concepts, including multiple beam, high-order mode operation, and new geometry configurations of old concepts. At the same time, a new simulation capability, based upon finite-difference “cut-cell” boundaries, has emerged and is transforming the existing modeling and design capability with unparalleled realism, greater flexibility, and improved accuracy. This same new technology can also be brought to bear on a difficult-to-study aspect of the energy recovery linac (ERL), namely the accurate modeling of the exit beam, and design of the beam dump for optimum energy efficiency. We have developed new capability for design calculations and modeling of a broad class of devices which convert bunched beam kinetic energy to RF energy, including RF sources, as for example, klystrons, gyro-klystrons, IOT's, TWT’s, and other devices in which space-charge effects are important. Recent advances in geometry representation now permits very accurate representation of the curved metallic surfaces common to RF sources, resulting in unprecedented simulation accuracy. In the Phase I work, we evaluated and demonstrated the capabilities of the new geometry representation technology as applied to modeling and design of output cavity components of klystron, IOT's, and energy recovery srf cavities. We identified and prioritized which aspects of the design study process to pursue and improve in Phase II. The development and use of the new accurate geometry modeling technology on RF sources for DOE accelerators will help spark a new generational modeling and design capability, free from many of the constraints and inaccuracy associated with the previous generation of “stair-step” geometry modeling tools. This new capability is ultimately expected to impact all fields with high power RF sources, including DOE fusion research, communications, radar and

  2. Electron transport of a Linac Coherent Light Source (LCLS) using the SLAC linac

    SciTech Connect

    Bane, K.L.; Raubenheimer, T.O.; Seeman, J.T.

    1993-05-01

    A linac configuration providing a low emittance high peak current electron beam is under study for a potential Linac Coherent Light Source (LCLS) based on the SLAC accelerator. The parameters of the final electron bunch are nearing the technological limits of present accelerators in both transverse and longitudinal phase space. In this note we describe a layout of the RF gun, linac, and bunch compressors to deliver the required bunch properties. We consider a bunch that is generated by an rf gun and accelerated to 7 GeV in 900 m of SLAC linac structure before it enters the wiggler. We assume that the rf gun generates a gaussian beam with an energy of 10 MeV, a population N = 6 {times} 10{sup 9}e{sup {minus}}, an rms length {sigma}{sub z} = 0.5 mm, an rms energy spread {sigma}{sub {delta}} = 0.2%, and normalized rms emittances {gamma}{epsilon}{sub x,y} = 3 mm-mrad. At the end of the linac, we require that the peak current {cflx I} {approx_gt} 2.5 kA and the peak-to-peak energy spread {Delta}{delta} {approx_lt} 0.2%. To obtain the required high peak current, we need to compress the bunch length by a factor greater than 10. In deciding at what position in the linac to compress we need to consider three issues: the longitudinal wakefield in the linac, this increases the beam`s energy spread and is harder to compensate with short bunches, the transverse wakefield and rf deflections in the linac, these increase the transverse emittance of the beam and are more severe for long bunches, and the effects of phase and current jitter which will change the bunch length and therefore the peak current of the beam. In this paper, we will describe how we compress the bunch to meet these three criteria. Then, we will briefly describe the bunch compressor optics and finally we will mention some details specific to the SLAC site.

  3. R and D energy recovery LINAC at Brookhaven National Laboratory

    SciTech Connect

    Litvinenko,V.N.; Beavis, D.; Ben-Zvi, I.; Blaskiewicz, M.; Burrill, A.; Calaga, R.; Cameron, P.; Chang, X.; Drees, A.; Ganetis, G.; Gassner, D.; Hahn, H.; Hammons, L.; Hershcovitch, A.; Hseuh, H-C.; Jain, A.; Kayran, D.; Kewisch, J.; Lambiase, R.; Lederle, D.; Mahler, G.; McIntyre, G.; Meng, W.; Nehring, T.; Oerter, B.; Pai, C.; Pate, D.; Phillips, D.; Pozdeyev, E.; Rao, T.; Reich, J.; Roser, T.; Russo, T.; Smith, K.; Tuozzolo, J.; Weiss, D.; Williams, N.; Yip, K.; Zaltsman, A.; Favale, A.; Bluem, H.; Cole, M.; Holmes, D.; Rathke, J.; Schultheiss, T.; Todd, A.; Delayen, J.; Funk, L.; Phillips, L.; Preble, J.

    2008-06-23

    Collider Accelerator Department at BNL is in the final stages of developing the 20-MeV R and 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. Recent development in the R and D ERL plans include gun and 5-cell cavity (G5) test and possibility of using R and D ERL for proof-of-principle test of Coherent Electron Cooling at RHIC.

  4. Commissioning of the LCLS Linac and Bunch Compressors

    SciTech Connect

    Akre, R.; Brachmann, A.; Decker, F.-J.; Ding, Y.; Dowell, D.; Emma#, P.; Frisch, J.; Gilevich, S.; Hays, G.; Hering, Ph.; Huang, Z.; Iverson, R.; Limborg-Deprey, C.; Loos, H.; Molloy, S.; Miahnahri, A.; Nuhn, H.-D.; Ratner, D.; Turner, J.; Welch, J.; White, W.; /SLAC

    2008-08-20

    The Linac Coherent Light Source (LCLS) is a SASE x-ray Free-Electron Laser (FEL) project under construction at SLAC [1]. The injector section, from drive-laser and RF photocathode gun through the first bunch compressor, was commissioned in the spring and summer of 2007. The second phase of commissioning, including the second bunch compressor and various main linac modifications, was completed in January through August of 2008. We report here on experience gained during this second phase of machine commissioning, including the injector, the first and second bunch compressor stages, the linac up to 14 GeV, and beam stability measurements. The final commissioning phase, including the undulator and the long transport line from the linac, is set to begin in December 2008, with first light expected in July 2009.

  5. The 400 MeV Linac Upgrade at Fermilab

    SciTech Connect

    Noble, R.J.

    1992-12-01

    The Fermilab Linac Upgrade in planned to increase the energy of the H{sup {minus}} linac from 200 to 400 MeV. This is intended to reduce the incoherent space-charge tuneshift at injection into the 8 GeV Booster which limit either the brightness or the total intensity of the beam. The Linac Upgrade will be achieved by replacing the last four 201.25 MHs drift-tube linac (DTL) tanks which accelerate the beam from 116 to 200 MeV, with seven 805 MRs side-coupled cavity modules operating at an average axial field of about 7.5 MV/meter. This will allow acceleration to 400 MeV in the existing Linac enclosure. Each accelerator module will be driven with a 12 MW klystron-based rf power supply. Three of seven accelerator modules have been fabricated, power tested and installed in their temporary location adjacent to the existing DTL. All seven RF Modulators have been completed and klystron installation has begun. Waveguide runs have completed from the power supply gallery to the accelerator modules. The new linac will be powered in the temporary position without beam in order to verify overall system reliability until the laboratory operating schedule permits final conversion to 400 MeV operation.

  6. Projected performance of rf-linac-driven free-electron lasers in the extreme-ultraviolet spectral region

    SciTech Connect

    Newman, B.E.

    1988-01-01

    A free-electron laser user facility for scientific experimentation in the vacuum-ultraviolet and soft x-ray spectral regions (together termed the XUV) is being developed at Los Alamos. The design includes a series of laser oscillators and amplifiers, driven by a single, rf-linear accelerator, that will generate broadly tunable, picosecond-pulse, coherent radiation from 1 to 400 nm. Below 300 nm, the peak- and average-power output of these FEL devices should surpass the capabilities of any existing, continuously tunable photon sources by many orders of magnitude. The design and output parameters of this facility will be described, including comparison with synchrotron radiation sources, and recent progress in developing the three primary components (electron beam, magnetic undulator, and resonator mirrors) will be reviewed. 23 refs., 2 figs., 2 tabs.

  7. Lattice Design for the LHEC Recirculating Linac

    SciTech Connect

    Sun, Yipeng; Eide, Anders; Zimmermann, Frank; Adolphsen, Chris; /SLAC

    2011-05-20

    In this paper, we present a lattice design for the Large Hadron Electron Collider (LHeC) recirculating linac. The recirculating linac consists of one roughly 3-km long linac hosting superconducting RF (SRF) accelerating cavities, two arcs and one transfer line for the recirculation. In two passes through a pulsed SRF linac the electron beam can get a maximum energy of 140 GeV. Alternatively, in the Energy Recovery Linac (ERL) option the beam passes through a CW linac four times (two passes for acceleration and two for deceleration) for a maximum energy of 60 GeV.

  8. Fast energy and energy spectrum feedback in the SLC Linac

    SciTech Connect

    Abrams, G.S.; Soderstrom, E.; Seeman, J.T.; Campisi, I.E.; Herrmannsfeldt, W.; Lee, M.; Petersen, A.; Phinney, N.; Ross, M.; Thompson, K.

    1987-01-01

    The energies and energy spectra of the positron and electron beams emerging from the SLC Linac must be carefully maintained so that the beams can be transported through the Arcs to the Final Focus without phase space dilution and also to specify the collision energy. A fastback system has been designed and constructed to control these parameters. The energies and energy spectra are measured nondestructively using position monitors and synchrotron radiation width monitors. The controls consist of rf phases in the Damping Rings, SLED timing, and rf amplitude. Theoretical aspects of the feedback process, algorithms, and operational experience are discussed.

  9. High Repetition Rate, LINAC-Based Nuclear Resonance Fluorescence FY 2008 Final Report

    SciTech Connect

    Scott M Watson; Mathew T Kinlaw; James L Jones; Alan W. Hunt; Glen A. Warren

    2008-12-01

    This summarizes the first year of a multi-laboratory/university, multi-year effort focusing on high repetition rate, pulsed LINAC-based nuclear resonance fluorescence (NRF) measurements. Specifically, this FY2008 effort centered on experimentally assessing NRF measurements using pulsed linear electron accelerators, operated at various repetition rates, and identifying specific detection requirements to optimize such measurements. Traditionally, interest in NRF as a detection technology, which continues to receive funding from DHS and DOE/NA-22, has been driven by continuous-wave (CW), Van de Graff-based bremsstrahlung sources. However, in addition to the relatively sparse present-day use of Van de Graff sources, only limited NRF data from special nuclear materials has been presented; there is even less data available regarding shielding effects and photon source optimization for NRF measurements on selected nuclear materials.

  10. The SLAC linac as used in the SLC collider

    SciTech Connect

    Seeman, J.T.; Abrams, G.; Adolphsen, C.; Atwood, W.; Bane, K.L.F.; Iverson, R.; Jacobsen, R.; Himel, T.M.; Jobe, R.K.; Lavine, T.L.

    1989-06-01

    The linac of the SLAC Linear Collider (SLC) must accelerate three high intensity bunches on each linac pulse from 1.2 GeV to 50 GeV with minimal increase of the small transverse emittance. The procedures and adjustments used to obtain this goal are outlined. Some of the accelerator parameters and components which interact are the beam energy, transverse position, component alignment, RF manipulation, feedback systems, quadrupole lattice, BNS damping, energy spectra, phase space matching, collimation, instrumentation and modelling. The method to bring these interdependent parameters collectively into specification has evolved over several years. This review is ordered in the sequence which is used to turn on the linac from a cold start and produce acceptable beams for the final focus and collisions. Approximate time estimates for the various activities are given. 21 refs.

  11. S-Band Loads for SLAC Linac

    SciTech Connect

    Krasnykh, A.; Decker, F.-J.; 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.

  12. Space charge in proton linacs

    SciTech Connect

    Wangler, T.P.; Merrill, F.; Rybarcyk, L.; Ryne, R.

    1998-12-31

    There are at least two reasons for the interest in space-charge effects in proton linacs. First, it can be expected that there are some areas of commonality in the space-charge physics of linacs and circular machines. Second, a linac delivers the input beam to a circular machine, so understanding the linac physics helps to explain the limitations for the input beam quality to a ring. This presentation is divided into three parts. First, the authors discuss space-charge effects form the linac point of view. Second, they discuss practical methods of calculation of linac beam dynamics that include space-charge forces. Finally, they summarize the status of experimental studies of the beam performance in the LANSCE linac including space-charge effects.

  13. A feasibility study of space-charge neutralized ion induction linacs: Final report

    SciTech Connect

    Slutz, S.A.; Primm, P.; Renk, T.; Johnson, D.J.

    1997-03-01

    Applications for high current (> 1 kA) ion beams are increasing. They include hardening of material surfaces, transmutation of radioactive waste, cancer treatment, and possibly driving fusion reactions to create energy. The space-charge of ions limits the current that can be accelerated in a conventional ion linear accelerator (linac). Furthermore, the accelerating electric field must be kept low enough to avoid the generation and acceleration of counter-streaming electrons. These limitations have resulted in ion accelerator designs that employ long beam lines and would be expensive to build. Space-charge neutralization and magnetic insulation of the acceleration gaps could substantially reduce these two limitations, but at the expense of increasing the complexity of the beam physics. We present theory and experiments to determine the degree of charge-neutralization that can be achieved in various environments found in ion accelerators. Our results suggest that, for high current applications, space-charge neutralization could be used to improve on the conventional ion accelerator technology. There are two basic magnetic field geometries that can be used to insulate the accelerating gaps, a radial field or a cusp field. We will present studies related to both of these geometries. We shall also present numerical simulations of {open_quotes}multicusp{close_quotes} accelerator that would deliver potassium ions at 400 MeV with a total beam power of approximately 40 TW. Such an accelerator could be used to drive fusion.

  14. Design, construction, system integration, and test results of the 1 MW CW RF system for the e-gun cavity in the energy recovery LINAC at Brookhaven National Laboratory

    SciTech Connect

    Lenci,S.J.; Eisen, E. L.; Dickey, D. L.; Sainz, J. E.; Utay, P. F.; Zaltsman, A.; Lambiase, R.

    2009-05-04

    Brookhaven's ERL (Energy Recovery LINAC) requires a 1 MW CW RF system for the superconducting electron gun cavity. The system consists primarily of a klystron tube, transmitter, and High-Voltage Power Supply (HVPS). The 703.75 MHz klystron made by CPl, Inc. provides RF power of 1MW CW with efficiency of 65%. It has a single output window, diode-type electron gun, and collector capable of dissipating the entire beam power. It was fully factory tested including 24-hour heat run at 1.1 MW CWo The solid state HVPS designed by Continental Electronics provides up to 100 kV at low ripple and 2.1 MW CW with over 95% efficiency. With minimal stored energy and a fast shut-down mode no crowbar circuit is needed. Continental 's transmitter includes PLC based user interface and monitoring, RF pre-amplifier, magnet and Vac-Ion pump supplies, cooling water instrumentation, and integral safety interlock system. BNL installed the klystron, HVPS, and transmitter along with other items, such as circulator, water load, and waveguide components. The collaboration of BNL, CPI, and Continental in the design, installation, and testing was essential to the successful operation of the 1MW system.

  15. Scaling of Wakefield Effects in Recirculating Linacs

    SciTech Connect

    L. Merminga; G. R. Neil; B. C. Yunn; J. J. Bisognano

    2001-07-01

    Expressions for the induced energy spread and emittance degradation of a single bunch due to the longitudinal and transverse impedance of rf cavities at the end of a linac structure are presented. Scaling of the formulae with rf frequency is derived. Scaling of the threshold current for the multibunch, multipass beam breakup (BBU) instability in recirculating linacs with accelerator and beam parameters is also derived.

  16. SSC linac injector

    SciTech Connect

    Bhatia, T.S.; Guy, F.W.; Neuschaefer, G.H.; Pabst, M.; Schriber, S.O.; Stovall, J.E.; Wangler, T.P.; Wilson, M.T.; Worth, G.T.

    1988-01-01

    The parameters for the proposed SSC linac injector system are obtained from the established requirements of the low-energy booster (LEB). The first element of this injector system is a radio-frequency quadrupole (RFQ) that bunches the H/sup /minus// ions and accelerates these ion bunches to 2.5 MeV. With a suitable matching section, this beam is injected into a drift-tube linac (DTL), which takes the ions to 120 MeV. The final element is a coupled-cavity linac (CCL) designed to accelerate the H/sup /minus// ions to 600 MeV for injection into the LEB. The conceptual beam dynamics design for the various elements of this linac injector system are described. 4 refs., 5 figs., 4 tabs.

  17. LCLS LLRF Upgrades to the SLAC Linac

    SciTech Connect

    Akre, R.; Dowell, D.; Emma, P.; Frisch, J.; Hong, B.; Kotturi, K.; Krejcik, P.; Wu, J.; Byrd, J.; /LBL, Berkeley

    2007-10-04

    The Linac Coherent Light Source (LCLS) at SLAC will be the brightest X-ray laser in the world when it comes on line. In order to achieve the brightness a 200fS length electron bunch is passed through an undulator. To create the 200fS, 3kA bunch, a 10pS electron bunch, created from a photo cathode in an RF gun, is run off crest on the RF to set up a position to energy correlation. The bunch is then compressed by chicanes. The stability of the RF system is critical in setting up the position to energy correlation. Specifications derived from simulations require the RF system to be stable to below 200fS in several critical injector stations and the last kilometer of linac. The SLAC linac RF system is being upgraded to meet these requirements.

  18. A Stability of LCLS Linac Modulators

    SciTech Connect

    Decker, F.-J.; Krasnykh, A.; Morris, B.; Nguyen, M.; /SLAC

    2012-06-13

    Information concerning to a stability of LCLS RF linac modulators is allocated in this paper. In general a 'pulse-to-pulse' modulator stability (and RF phase as well) is acceptable for the LCLS commission and FEL programs. Further modulator stability improvements are possible and approaches are discussed based on our experimental results.

  19. Beam break up analysis for the Berkeley Recirculating Linac Light Source

    SciTech Connect

    De Santis, Stefano; Zholents, Alexander A.

    2002-01-20

    We describe here a study of a single bunch Beam Break Up (BBU) instability for a proposed Berkeley fast x-ray facility based on a recirculating linac [1]. The recirculating linac employs a 600 MeV superconducting RF linear accelerator and the electron beam energy of {approx} 2.5 GeV is reached over four beam passes through the linac. A 120 MeV superconducting RF linear accelerator is used as an injector to the recirculating linac. The machine parameters are listed in Appendix A. The equation describing the transverse displacement x(s,z) of the electrons in an accelerated bunch, as a function of their longitudinal position within the bunch z, can be written in the form [2]: d/ds[{gamma}(s) dx/ds] + k{sup 2}(s){gamma}(s)x(s,z) = r{sub 0}{integral}{sub z}{sup {infinity}}{rho}(z')W{sub {perpendicular}}(z'-z)x(s,z')dz' (1) where {gamma} is the relativistic factor, k the focusing strength, r{sub 0} the classical electron radius, {rho} the bunch density, W{sub {perpendicular}} the transverse wake function per unit length and s indicates the position along the linac. We assume infinitesimally small transverse beam dimensions (a good approximation, when the bunch dimensions are much less than the size of the beam pipe), so that x has to be interpreted as the displacement of the centre of a bunch slice. We also assume a bunch length much less than the betatron wavelength, therefore the displacement in the RHS of Eq.(1) is not retarded and, finally, we use an average transverse wake function obtained averaging the calculated short range wake of a single cavity [2] over the linac length. At first we consider the effect associated with a displacement of the electron bunch at the injection into the perfectly aligned linac. Later we extend the analysis to the case of misalignments of the linac RF cavities and cryomodules. Throughout the paper we compare the results obtained to the output of a simple tracking code, written as a Mathematical notebook. In order to keep the

  20. Ultra-secure RF Tags for Safeguards and Security - SBIR Phase II Final Report

    SciTech Connect

    Twogood, Richard E

    2015-01-27

    This is the Final Report for the DOE Phase II SBIR project “Ultra-secure RF Tags for Safeguards and Security.” The topics covered herein include technical progress made, progress against the planned milestones and deliverables, project outcomes (results, collaborations, intellectual property, etc.), and a discussion on future expectations of deployment and impacts of the results of this work. In brief, all planned work for the project was successfully completed, on or ahead of schedule and on budget. The major accomplishment was the successful development of a very advanced passive ultra-secure RFID tag system with combined security features unmatched by any commercially available ones. These tags have high-level dynamic encrypted authentication, a novel tamper-proofing mechanism, system software including graphical user interfaces and networking, and integration with a fiber-optic seal mechanism. This is all accomplished passively (with no battery) by incorporating sophisticated hardware in the tag which harvests the energy from the RFID readers that are interrogating the tag. Based on initial feedback (and deployments) at DOE’s Lawrence Livermore National Laboratory (LLNL), it is anticipated these tags and their offspring will meet DOE and international community needs for highly secure RFID systems. Beyond the accomplishment of those original objectives for the ultra-secure RF tags, major new spin-off thrusts from the original work were identified and successfully pursued with the cognizance of the DOE sponsor office. In particular, new classes of less sophisticated RFID tags were developed whose lineage derives from the core R&D thrusts of this SBIR. These RF “tag variants” have some, but not necessarily all, of the advanced characteristics described above and can therefore be less expensive and meet far wider markets. With customer pull from the DOE and its national laboratories, new RFID tags and systems (including custom readers and software) for

  1. A study of a test APF-IH type linac as an injector for cancer therapy

    NASA Astrophysics Data System (ADS)

    Hattori, T.; Yamamoto, K.; Hayashizaki, N.; Kashiwagi, H.; Takahashi, Y.; Hata, T.; Okada, S.; Sugita, T.; Aoki, M.; Okamura, M.; Yamada, S.; Osvath, E.; Dudu, D.; Vata, I.

    2002-04-01

    We are studying a heavy-ion interdigital H (IH) type linear accelerator as an injector for a cancer therapy synchrotron. The compact IH linac accelerates C 4+ ions from 65 keV/u up to 6 MeV/u with an alternating phase focus (APF) structure. The linac cavity is 3.1 m in length and operates at a frequency of 100 MHz. A test APF-IH linac was designed to accelerate C 4+ ions from 40 keV/u to 2 MeV/u with an operating frequency of 100 MHz. From particle orbit calculations, using an energy width of ±0.2%, this linac can accept a transverse emittance of 100 π mm mrad, a longitudinal phase of 35° and a beam intensity of several 100 μA. The test cavity has 1.4 m in length and 56 cm in diameter. We made a basic, half-scale model cavity of this linac and plan to measure its RF characteristics. Using the results of these measurements, a final design of this linac will be determined.

  2. Microbunching and RF Compression

    SciTech Connect

    Venturini, M.; Migliorati, M.; Ronsivalle, C.; Ferrario, M.; Vaccarezza, C.

    2010-05-23

    Velocity bunching (or RF compression) represents a promising technique complementary to magnetic compression to achieve the high peak current required in the linac drivers for FELs. Here we report on recent progress aimed at characterizing the RF compression from the point of view of the microbunching instability. We emphasize the development of a linear theory for the gain function of the instability and its validation against macroparticle simulations that represents a useful tool in the evaluation of the compression schemes for FEL sources.

  3. Availability and Failure Effects of NLC Main Linac Mechanical Movers(LCC-0141)

    SciTech Connect

    Himel, T

    2004-05-24

    We analyze the probability of failure and the failure effects of the quadrupole and RF girder translation stages (''movers'') in the 500 GeV CM NLC Main Linac. In order to achieve its alignment tolerances, the NLC main linac will require a large installation of remote controlled translation stages with multiple degrees of freedom. In particular, each of the 591 quads in each 250 GeV main linac will be mounted on a magnet mover with 3 degrees of freedom (x, y, roll); each of the 2304 RF structure girders in each linac will be mounted on a girder mover with 5 degrees of freedom (x, y, roll, pitch, yaw). Simulation studies of main linac operation typically assume that all movers are operational at all times, in order to limit the complexity of the simulation. This is obviously not a realistic expectation for a system with so many components, especially when the number of sub-elements of each mover (stepper motors, rotary encoders, position transducers, cabling, control electronics, database, operator) are considered. The unavailability risk of the mover system is of particular concern for the NLC, since very few accelerators have ever been built with such a large fraction of its beamline hardware on remote-controlled translation stages. In order to predict the availability of the movers, it is necessary to estimate a few quantities, specifically: how often will a mover break (mean time between failures, or MTBF); how long will it take to repair a mover (mean time to repair, or MTTR); what is the performance ''hit'' which accrues when movers are broken? To answer the first two questions we used historical failure data from the two large mover systems at SLAC, in the arcs of the Stanford Linear Collider (SLC) and in the Final Focus Test Beam (FFTB). For the final question, we can get some estimate from simulation studies of the NLC main linac in normal operation.

  4. ILC Linac R&D at SLAC

    SciTech Connect

    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.

  5. Review of pulsed rf power generation

    SciTech Connect

    Lavine, T.L.

    1992-04-01

    I am going to talk about pulsed high-power rf generation for normal-conducting electron and positron linacs suitable for applications to high-energy physics in the Next Linear Collider, or NLC. The talk will cover some basic rf system design issues, klystrons and other microwave power sources, rf pulse-compression devices, and test facilities for system-integration studies.

  6. Final Results on RF and Wake Kicks Caused by the Couplers for the ILC Cavity

    SciTech Connect

    Lunin, Andrei; Gonin, Ivan; Solyak, Nikolay; Yakovlev, Vyacheslav; /Fermilab

    2010-05-01

    In the paper the results are presented for calculation of the transverse wake and RF kick from the power and HOM couplers of the ILC acceleration structure. The RF kick was calculated stand-alone by HFSS, CST MWS and COMSOL codes while the wake kick was calculated by GdfidL. The calculation precision and convergence for both cases are discussed and compared to the results obtained independently by other group.

  7. Final Technical Report- Back-gate Field Emission-based Cathode RF Electron Gun

    SciTech Connect

    McGuire, Gary; Martin, Allen; Noonan, John

    2010-10-30

    The objective was to complete the design of an electron gun which utilizes a radio frequency (RF) power source to apply a voltage to a field emission (FE) cathode, a so called cold cathode, in order to produce an electron beam. The concept of the RF electron gun was originally conceived at Argonne National Laboratory but never reduced to practice. The research allowed the completion of the design based upon the integration of the FE electron source. Compared to other electron guns, the RF gun is very compact, less than one third the size of other comparable guns, and produces a high energy (to several MeV), high quality, high power electron beam with a long focal length with high repetition rates. The resultant electron gun may be used in welding, materials processing, analytical equipment and waste treatment.

  8. Overview of High Power Vacuum Dry RF Load Designs

    SciTech Connect

    Krasnykh, Anatoly

    2015-08-27

    A specific feature of RF linacs based on the pulsed traveling wave (TW) mode of operation is that only a portion of the RF energy is used for the beam acceleration. The residual RF energy has to be terminated into an RF load. Higher accelerating gradients require higher RF sources and RF loads, which can stably terminate the residual RF power. RF feeders (from the RF source though the accelerating section to the load) are vacuumed to transmit multi-megawatt high power RF. This overview will outline vacuumed RF loads only. A common method to terminate multi-MW RF power is to use circulated water (or other liquid) as an absorbing medium. A solid dielectric interface (a high quality ceramic) is required to separate vacuum and liquid RF absorber mediums. Using such RF load approaches in TW linacs is troubling because there is a fragile ceramic window barrier and a failure could become catastrophic for linac vacuum and RF systems. Traditional loads comprising of a ceramic disk have limited peak and average power handling capability and are therefore not suitable for high gradient TW linacs. This overview will focus on ''vacuum dry'' or ''all-metal'' loads that do not employ any dielectric interface between vacuum and absorber. The first prototype is an original design of RF loads for the Stanford Two-Mile Accelerator.

  9. Beam Dynamics Study of X-Band Linac Driven X-Ray FELS

    SciTech Connect

    Adolphsen, C.; Limborg-Deprey, C.; Raubenheimer, T.O.; Wu, J.; Sun, Y.; /SLAC

    2011-12-13

    Several linac driven X-ray Free Electron Lasers (XFELs) are being developed to provide high brightness photon beams with very short, tunable wavelengths. In this paper, three XFEL configurations are proposed that achieve LCLS-like performance using X-band linac drivers. These linacs are more versatile, efficient and compact than ones using S-band or C-band rf technology. For each of the designs, the overall accelerator layout and the shaping of the bunch longitudinal phase space are described briefly. During the last 40 years, the photon wavelengths from linac driven FELs have been pushed shorter by increasing the electron beam energy and adopting shorter period undulators. Recently, the wavelengths have reached the X-ray range, with FLASH (Free-Electron Laser in Hamburg) and LCLS (Linac Coherent Light Source) successfully providing users with soft and hard X-rays, respectively. FLASH uses a 1.2 GeV L-band (1.3 GHz) superconducting linac driver and can deliver 10-70 fs FWHM long photon pulses in a wavelength range of 44 nm to 4.1 nm. LCLS uses the last third of the SLAC 3 km S-band (2.856 GHz) normal-conducting linac to produce 3.5 GeV to 15 GeV bunches to generate soft and hard X-rays with good spatial coherence at wavelengths from 2.2 nm to 0.12 nm. Newer XFELs (at Spring8 and PSI) use C-band (5.7 GHz) normal-conducting linac drivers, which can sustain higher acceleration gradients, and hence shorten the linac length, and are more efficient at converting rf energy to bunch energy. The X-band (11.4 GHz) rf technology developed for NLC/GLC offers even higher gradients and efficiencies, and the shorter rf wavelength allows more versatility in longitudinal bunch phase space compression and manipulation. In the following sections, three different configurations of X-band linac driven XFELs are described that operate from 6 to 14 GeV. The first (LOW CHARGE DESIGN) has an electron bunch charge of only 10 pC; the second (OPTICS LINEARIZATION DESIGN) is based on optics

  10. Upgrade of the H^--injection system at the DESY proton Linac III

    NASA Astrophysics Data System (ADS)

    Kleffner, C.-M.; Holtkamp, N.; Jacobs, G.; Nagl, M.; Deitinghoff, H.; Paramonov, V.

    1997-05-01

    In the near future an upgrade of the injection system of the proton linac at DESY is foreseen. Two different types of H^--sources are operated at DESY. The new rf-driven volume source is cesium free. On a long-term basis this source is planned to replace the operating magnetron source. For reasons of reliability of the proton linac and further developments of sources parallel operation of two sources should be possible at the the Alvarez linac. Each source has a separate RFQ to accelerate the ions to an energy of 750 keV. A new transport line with one dipole, 8 quadrupoles and one intermediate buncher was designed to match the beam between both RFQs and the Alvarez linac. The codes COPPOC and TRANSPORT were used for determining the length of the transport line and the parameters of the dipole and the buncher. Because of the high currents of more than 20 mA the estimate of the space charge forces is of special interest. The macro-particle-code PARMTRA takes into account the particle-to-particle electric forces among all particles. The properties of the beam line have been studied in connection with the effects of the final beam quality after acceleration with the 50 MeV Alvarez linac.

  11. New medical linacs

    NASA Astrophysics Data System (ADS)

    Schonberg, R. G.; Mishin, A. V.

    1997-02-01

    X-band linacs designed and manufactured by Schonberg Research Corporation that are currently used by two spin-off companies for radiation therapy systems. Accuray employs a basic 6 MeV design with 300 R/min nominal dose rate at 80 cm from a tungsten target. The designed stereoscopic radiosurgery system is known as the Cyberknife. The Cyberknife combines a treatment planning, imaging and treatment delivery features. The treatment delivery system enclosure incorporates an accelerator head, RF components, pulse transformer and electronics mounted on a robotic arm. Intraop Medical, Inc. has introduced a system for intraoperative radiation therapy (IORT) called Mobetron (Mobile Electron Beam Intraoperative Treatment System). Mobetron is based on a 12 MeV two section X-band linac also designed by Schonberg Research Corporation. The accelerator design permits smooth energy variation from 4 to 12 MeV, but will be used at 4 specific energies. A self-shielded concept is applied to the system design. It will be used in conventional operating rooms without added shielding.

  12. Applications for the RFD linac structure

    NASA Astrophysics Data System (ADS)

    Swenson, Donald A.

    2001-07-01

    With the successful completion and operation of the "Proof-of-Principle" prototype of the Rf Focused Drift tube (RFD) linac structure, our attention has now turned to the identification of the first applications for this new compact and economical linac structure. The principal medical applications are for the production of short-lived radioisotopes for the positron emission tomography (PET and SPECT) application, epithermal neutron beams for the boron neutron capture therapy (BNCT) application, and nanoamperes of energetic (250 MeV) protons for proton therapy. The structure can be configured as a compact injector linac for proton synchrotrons. The structure can be configured as a pulsed cold neutron source to support cold neutron physics and its applications. The principal industrial applications include nondestructive testing (NDT), thermal neutron radiography (TNR), thermal neutron analysis (TNA), and pulsed fast neutron analysis (PFNA). Brief descriptions of these RFD-linac-based systems will be presented.

  13. Rf-plasma synthesis of nanosize silicon carbide and nitride. Final report

    SciTech Connect

    Buss, R.J.

    1997-02-01

    A pulsed rf plasma technique is capable of generating ceramic particles of 10 manometer dimension. Experiments using silane/ammonia and trimethylchlorosilane/hydrogen gas mixtures show that both silicon nitride and silicon carbide powders can be synthesized with control of the average particle diameter from 7 to 200 nm. Large size dispersion and much agglomeration appear characteristic of the method, in contrast to results reported by another research group. The as produced powders have a high hydrogen content and are air and moisture sensitive. Post-plasma treatment in a controlled atmosphere at elevated temperature (800{degrees}C) eliminates the hydrogen and stabilizes the powder with respect to oxidation or hydrolysis.

  14. LLRF System Upgrade for the SLAC Linac

    SciTech Connect

    Hong, Bo; Akre, Ron; Pacak, Vojtech; /SLAC

    2012-07-06

    The Linac Coherent Light Source (LCLS) at SLAC is in full user operation and has met the stability goals for stable lasing. The 250pC bunch can be compressed to below 100fS before passing through an undulator. In a new mode of operation a 20pC bunch is compressed to about 10fS. Experimenters are regularly using this shorter X-ray pulse and getting pristine data. The 10fS bunch has timing jitter on the order of 100fS. Physicists are requesting that the RF system achieve better stability to reduce timing jitter. Drifts in the RF system require longitudinal feedbacks to work over large ranges and errors result in reduced performance of the LCLS. A new RF system is being designed to help diagnose and reduce jitter and drift in the SLAC linac.

  15. RFI-Based Ion Linac Systems

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    Lettry, J; Fantz, U; Kronberger, M; Kalvas, T; Koivisto, H; Komppula, J; Mahner, E; Schmitzer, C; Sanchez, J; Scrivens, R; Midttun, O; Myllyperkiö, P; O'Neil, M; Pereira, H; Paoluzzi, M; Tarvainen, O; Wünderlich, D

    2012-02-01

    CERN's superconducting proton Linac (SPL) study investigates a 50 Hz high-energy, high-power Linac for H(-) 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(α), H(β), and H(γ) 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. PMID:22380238

  17. Conceptual design of the Project-X 1.3 GHz 3-8 GeV pulsed linac

    SciTech Connect

    Solyak, N.; Eidelman, Y.; Nagaitsev, S.; Ostiguy, J.-F.; Vostrikov, A.; Yakovlev, V.; /Fermilab

    2011-03-01

    Project-X, a multi-MW proton source, is under development at Fermilab. It enables a Long Baseline Neutrino Experiment via a new beam line pointed to DUSEL in Lead, South Dakota, and a broad suite of rare decay experiments. The initial acceleration is provided by a 3-GeV 1-mA CW superconducting linac. In a second stage, about 5% of the H{sup -} beam is accelerated up to 8 GeV in a 1.3 GHz SRF pulsed linac and injected into the Recycler/Main Injector complex. In order to mitigate problems with stripping foil heating during injection, higher current pulses are accelerated in the CW linac in conjunction with the 1 mA beam which is separated and further accelerated in the pulsed linac. The optimal current in the pulsed linac is discussed as well as the constraints that led to its selection. A conceptual design which covers optics and RF stability analysis is presented. Finally, the need for HOM damping is discussed.

  18. Thermal management of space-based, high-power solid-state RF amplifiers. Final report

    SciTech Connect

    Rose, M.F.; Chow, L.C.; Johnson, J.H.

    1990-08-01

    The advanced weapons concepts envisioned by the SDIO employed a wide array of highly energetic devices, which due to inefficiencies, generate large quantities of waste heat. Power and thermal management are integrally related. In the vacuum of space, disposing of waste energy is a major problem which can contribute as much as 50% to the overall spacecraft mass and volume. The problem becomes more acute as the temperature at which the energy must be rejected is lowered. In an earlier study, thermal management issues associated with megawatt class RF microwave tubes were explored to determine if there were simple, approximately mass neutral schemes which might be adapted to dispose of the waste energy generated within a tube collector operating in space. The assumptions for that study were: (1) Tubes were in the megawatt class-70% efficient for single simple collector and 90% efficient for depressed collectors, (2) On-board, super critical hydrogen was available at a pressure of 35 bars and a temperature of 35 K. (3) The largest single event run time was 500 seconds. (4) The device would be dormant for long periods of time, be required to become active in tens of seconds followed by long periods of dormancy. (5) The only allowable effluent is hydrogen. (6) System impact must be minimal.

  19. KEY COMPARISON: Final report on CCEM key comparison CCEM.RF-K10.CL (GT-RF/99-2) 'Power in 50 Ω coaxial lines, frequency: 50 MHz to 26 GHz' measurement techniques and results

    NASA Astrophysics Data System (ADS)

    Janik, Dieter; Inoue, T.; Michaud, A.

    2006-01-01

    This report summarizes the results and the measuring methods of an international key comparison between twelve national metrology institutes (NMIs) and is concerning the calibration factor of RF power sensors in the coaxial 3.5 mm line for frequencies up to 26 GHz. Two RF power travelling standards fitted with male PC 3.5 mm connectors were measured at seven frequencies. The following NMIs participated: NMIJ (Japan), NRC (Canada), NIST (USA), METAS (Switzerland), CSIR-NML (South Africa), NMIA (Australia), NPL (UK), SiQ (Slovenia), IEN (Italy), VNIIFTRI (Russian Federation), SPRING (Singapore) and PTB (Germany), as the pilot laboratory. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

  20. Spatially periodic radio-frequency quadrupole focusing linac

    NASA Astrophysics Data System (ADS)

    Kolomiets, A. A.; Plastun, A. S.

    2015-12-01

    The new design for a spatially periodical rf quadrupole focusing linac is proposed. It consists of accelerating gaps formed between conventional cylindrical drift tubes, between drift tubes and rf quadrupoles with nonzero axial potential, and inside these rf quadrupoles, formed in the same way as in a conventional radio-frequency quadrupole (RFQ) linac with modulated electrodes. Such a combination provides both higher energy gain rate than conventional RFQ and stability of transverse motion for ion beams. The structure can be designed using various combinations of quadrupoles and drift tubes. Some options are considered in the paper using the smooth approximation method and computer simulation of beam dynamics. Transverse stability of particles has been studied. The proposed structure can provide suppression of rf defocusing effects on transverse beam dynamics. Some limitations of the spatially periodic rf quadrupole structure are mentioned.

  1. Continued development of modeling tools and theory for rf heating. Final report

    SciTech Connect

    Smithe, D.N.

    1998-09-01

    The work performed during the grant has been reported long before this date, specifically in: (1) the grant`s annual performance report for 1991, MRC/WDC-R-277; (2) the published AIP Conference Proceedings {number_sign}244, Radio Frequency Power in Plasmas, Charleston, SC 1991, ``Evaluation of Wave Dispersion, Mode-Conversion, and Damping for ECRH with Exact Relativistic Corrections,`` by D.N. Smithe and P.L. Colestock; and (3) an unpublished paper entitled ``Temperature Anisotropy and Rotation Upgrades to the ICRF Modules in SNAP and TRANSP``, presented at the 1992 ICRF Modeling and Theory Workshop, at the Princeton Plasma Physics Laboratory. This final report contains copies of number (1). The specifics of the grant`s final months` activities, which to the authors recollection have never been reported to the DOE, are as follows. The original grant, which was to terminate August 15, 1991, was extended without additional funds to October 31, 1992. The primary reason for the extension was to permit attendance at the 1992 ICRF Modeling and Theory Workshop at the Princeton Plasma Physics Laboratory (PPPL), which was finally held August 17--18, 1992, after having been rescheduled several times during the summer of 1992. The body of this report contains copies of the 1991 annual report, which gives detailed discussion of the work accomplished.

  2. Coupled-cavity drift-tube linac

    DOEpatents

    Billen, J.H.

    1996-11-26

    A coupled-cavity drift-tube linac (CCDTL) combines features of the Alvarez drift-tube linac (DTL) and the {pi}-mode coupled-cavity linac (CCL). In one embodiment, each accelerating cavity is a two-cell, 0-mode DTL. The center-to-center distance between accelerating gaps is {beta}{lambda}, where {lambda} is the free-space wavelength of the resonant mode. Adjacent accelerating cavities have oppositely directed electric fields, alternating in phase by 180 degrees. The chain of cavities operates in a {pi}/2 structure mode so the coupling cavities are nominally unexcited. The CCDTL configuration provides an rf structure with high shunt impedance for intermediate velocity charged particles, i.e., particles with energies in the 20-200 MeV range. 5 figs.

  3. Coupled-cavity drift-tube linac

    DOEpatents

    Billen, James H.

    1996-01-01

    A coupled-cavity drift-tube linac (CCDTL) combines features of the Alvarez drift-tube linac (DTL) and the .pi.-mode coupled-cavity linac (CCL). In one embodiment, each accelerating cavity is a two-cell, 0-mode DTL. The center-to-center distance between accelerating gaps is .beta..lambda., where .lambda. is the free-space wavelength of the resonant mode. Adjacent accelerating cavities have oppositely directed electric fields, alternating in phase by 180 degrees. The chain of cavities operates in a .pi./2 structure mode so the coupling cavities are nominally unexcited. The CCDTL configuration provides an rf structure with high shunt impedance for intermediate velocity charged particles, i.e., particles with energies in the 20-200 MeV range.

  4. 10MeV 25KW industrial electron LINAC

    NASA Astrophysics Data System (ADS)

    Kamino, Y.

    1998-06-01

    A 10MeV 25KW plus class electron LINAC was developed for sterilisation of medical devices. The LINAC composed of a standing wave type single cavity prebuncher and a 2m electro-plated travelling wave guide uses a 5MW 2856MHz pulse klystron as an RF source and provides 25KW beam power at the Ti alloy beam window stably after the energy analysing magnet with 10MeV plus-minus 1 MeV energy slit. The practical maximum beam power reached 29 KW and this demonstrated the LINAC as one of the most powerful S-band electron LINACs in the world. The control of the LINAC is fully automated and the "One-Button Operation" is realised, which is valuable for easy operation as a plant system. 2 systems have been delivered and are being operated stably.

  5. The RIA driver linac.

    SciTech Connect

    Shepard, K. W.

    2002-09-23

    The driver linac for the U.S. RIA project will be a 1.4 GV superconducting linac capable of accelerating the full mass range of ions from 900 MeV protons to 400 MeV/u uranium, and delivering a cw beam of 400 kW shared by at least two targets simultaneously. Elements of the linac are being developed at several U.S. laboratories. The current status of linac design and development is reviewed with emphasis on changes in the baseline design since the last linac conference.

  6. RF power generation for future linear colliders

    SciTech Connect

    Fowkes, W.R.; Allen, M.A.; Callin, R.S.; Caryotakis, G.; Eppley, K.R.; Fant, K.S.; Farkas, Z.D.; Feinstein, J.; Ko, K.; Koontz, R.F.; Kroll, N.; Lavine, T.L.; Lee, T.G.; Miller, R.H.; Pearson, C.; Spalek, G.; Vlieks, A.E.; Wilson, P.B.

    1990-06-01

    The next linear collider will require 200 MW of rf power per meter of linac structure at relatively high frequency to produce an accelerating gradient of about 100 MV/m. The higher frequencies result in a higher breakdown threshold in the accelerating structure hence permit higher accelerating gradients per meter of linac. The lower frequencies have the advantage that high peak power rf sources can be realized. 11.42 GHz appears to be a good compromise and the effort at the Stanford Linear Accelerator Center (SLAC) is being concentrated on rf sources operating at this frequency. The filling time of the accelerating structure for each rf feed is expected to be about 80 ns. Under serious consideration at SLAC is a conventional klystron followed by a multistage rf pulse compression system, and the Crossed-Field Amplifier. These are discussed in this paper.

  7. THE CONVENTIONAL FACILITIES REQUIREMENTS FOR THE SNS LINAC

    SciTech Connect

    P. TALLERICO; M. CROW; ET AL

    2001-06-01

    The Spallation Neutron Source (SNS) linac has a high gradient and 2 MW of beam power, and it therefore requires substantial RF power and cooling. There are 94 klystrons in its RF system, a large number for a proton linac. The optimization process and logic that lead to the klystron, transmitter, and power supply sizes is discussed. We also describe the requirements for building and tunnel area, electrical power, and water for this system. The trade-off decisions between low capital cost, low operating cost, and good maintainability are described.

  8. Design of post linac to driver linac transport beam line in rare isotope accelerator

    NASA Astrophysics Data System (ADS)

    Kim, Chanmi; Kim, Eun-San

    2015-07-01

    We investigated the design of a beam transport line connecting the post linac to the driver linac (P2DT) in the Rare Isotope Accelerator (RAON). P2DT beam line is designed by 180° bending scheme to send the radioactive isotope separation on-line (ISOL) beams accelerated in the Linac-3 to Linac-2. The beam line is designed as a 180° bend for the transport of a multi-charge state 132Sn+45,+46,+47 beam. We used the TRACE 3-D, TRACK, and ORBIT codes to design the optics system, which also includes two bunchers and ten sextupole magnets for chromaticity compensation. The transverse emittance growth is minimized by adopting mirror symmetric optics and by correcting second-order aberrations using sextupoles. We report on the multi-charge state beam transport performance of the designed beam line. The main characteristics of the P2DT line are to minimize beam loss and the growth of emittance, and for charge stripping. Beam optics for P2DT is optimized for reducing beam loss and charge stripping. As Linac-3 may accelerate the stable beam and radioactive beam simultaneously, P2DT line also transports the stable beam and radioactive beam simultaneously. Thus, we need a RF switchyard to send the stable beam to the ISOL target and the radioactive beam to the high-energy experimental area in Linac-2 end.

  9. Designs for a Linac-Ring LHeC

    SciTech Connect

    Zimmermann, Frank; Bruning, Oliver; Ciapala, Edmond; Haug, Friedrich; Osborne, John; Schulte, Daniel; Sun, Yipeng; Tomas, Rogelio; Adolphsen, Chris; Calaga, Rama; Litvinenko, Vladimir; Chattopadhyay, Swapan; Dainton, John; Klein, Max; Eide, Anders; /Paris U., VI-VII

    2012-06-21

    We consider three scenarios for the recirculating electron linear accelerator (RLA) of a linac-ring type electron-proton 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 energy-recovery (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.

  10. Linac with integrated power source based on radio frequency energy compression

    NASA Astrophysics Data System (ADS)

    Smirnov, A. V.; Smirnov, V. N.

    1995-03-01

    The basic feasibility of a proposal to simplify the conventional low energy rf electron linear accelerator (linac), is considered. The design suggested foresees replacement of the traditional high power systems of external rf generator and modulator by a more passive switched energy storage system. The proposed conception of a compact linac is based on known rf energy compression techniques and an efficient self-excited oscillation in a special accelerating/oscillating linac structure. The principal relations, performance estimations, and one-dimensional time-dependent simulation results for such a linac are presented. The possibility of self-excited oscillation by an unbunched low voltage beam in a waveguide linac section is proved and investigated experimentally. The common features and differences compared with a conventional backward-wave tube are analyzed. An application of this effect is proposed for impedance and group velocity measurements in slow-wave structures. Since the rf energy commutation may be one or two orders faster than the electric high voltage energy commutation (conventional modulator), combining the structure proposed and rf energy compression system can give high levels of the average beam power (10-100 kW). The linac facility would have considerably reduced weight and sizes (more than 2.5 times) as compared to similar industrial linacs. The power supply required is in 40-120 kV range dc source, and an estimated overall wall plug efficiency is a few percent.

  11. Final Technical Report

    SciTech Connect

    Velasco, Mayda

    2013-11-01

    This work is focused on the design and construction of novel beam diagnostic and instrumentation for charged particle accelerators required for the next generation of linear colliders. Our main interest is in non-invasive techniques. The Northwestern group of Velasco has been a member of the CLIC Test Facility 3 (CTF3) collaboration since 2003, and the beam instrumentation work is developed mostly at this facility1. This 4 kW electron beam facility has a 25-170 MeV electron LINAC. CTF3 performed a set of dedicated measurements to finalize the development of our RF-Pickup bunch length detectors. The RF-pickup based on mixers was fully commissioned in 2009 and the RF-pickup based on diodes was finished in time for the 2010-11 data taking. The analysis of all the data taken in by the summer of 2010 was finish in time and presented at the main conference of the year, LINAC 2010 in Japan.

  12. The status of normal conducting RF (NCRF) guns, a summary of the ERL2005 workshop

    NASA Astrophysics Data System (ADS)

    Dowell, David H.; Lewellen, John W.; Nguyen, Dinh; Rimmer, Robert

    2006-02-01

    The 32nd Advanced ICFA Beam Dynamics Workshop on Energy Recovering Linacs (ERL2005) was held at Jefferson Laboratory, March 20-23, 2005. A wide range of ERL-related topics were presented and discussed in several working groups with Working Group 1 concentrating upon the physics and technology issues for DC, superconducting RF (SRF) and normal conducting RF (NCRF) guns. This paper summarizes the NCRF gun talks and reviews the status of NCRF gun technology. It begins with the presentations made on the subject of low-frequency, high-duty factor guns most appropriate for ERLs. One such gun at 433 MHz was demonstrated at 25%DF in 1992, while the CW and much improved version is currently being constructed at 700 MHz for LANL. In addition, the idea of combining the NCRF gun with a SRF linac booster was presented and is described in this paper. There was also a talk on high-field guns typically used for SASE-free electron lasers. In particular, the DESY coaxial RF feed design provides rotationally symmetric RF fields and greater flexibility in the placement of the focusing magnetic field. While in the LCLS approach, the symmetric fields are obtained with a dual RF feed and racetrack cell shape. Although these guns cannot be operated at high-duty factor, they do produce the best quality beams. With these limitations in mind, a section with material not presented at the workshop has been included in the paper. This work describes a re-entrant approach which may allow NCRF guns to operate with simultaneously increased RF fields and duty factors. And finally, a novel proposal describing a high-duty factor, two-frequency RF gun using a field emission source instead of a laser driven photocathode was also presented.

  13. The status of normal conducting RF (NCRF) guns; a summary of the ERL2005 Workshop

    SciTech Connect

    D.H. Dowell; J.W. Lewellen; D. Nguyen; R.A. Rimmer

    2005-03-19

    The 32nd Advanced ICFA Beam Dynamics Workshop on Energy Recovering Linacs (ERL2005) was held at Jefferson Laboratory, March 20 to 23, 2005. A wide range of ERL-related topics were presented and discussed in several working groups with Working Group 1 concentrated upon the physics and technology issues for DC, superconducting RF (SRF) and normal conducting RF (NCRF) guns. This paper summarizes the NCRF gun talks and reviews the status of NCRF gun technology. It begins with the presentations made on the subject of low-frequency, high-duty factor guns most appropriate for ERLs. One such gun at 433MHz was demonstrated at 25%DF in 1992, while the CW and much improved version is currently being constructed at 700MHz for LANL. In addition, the idea of combining the NCRF gun with a SRF linac booster was presented and is described in this paper. There was also a talk on high-field guns typically used for SASE free electron lasers. In particular, the DESY coaxial RF feed design provides rotationally symmetric RF fields and greater flexibility in the placement of the focusing magnetic field. While in the LCLS approach, the symmetric fields are obtained with a dual RF feed and racetrack cell shape. Although these guns cannot be operated at high-duty factor, they do produce the best quality beams. With these limitations in mind, a section with material not presented at the workshop has been included in the paper. This work describes a re-entrant approach which may allow NCRF guns to operate with simultaneously increased RF fields and duty factors. And finally, a novel proposal describing a high-duty factor, two-frequency RF gun using a field emission source instead of a laser driven photocathode was also presented.

  14. The Status of Normal Conducting RF (NCRF) Guns, a Summary of the ERL2005 Workshop

    SciTech Connect

    Dowell, D.H.; Lewellen, J.W.; Nguyen, D.; Rimmer, R.; /Jefferson Lab

    2006-03-13

    The 32nd Advanced ICFA Beam Dynamics Workshop on Energy Recovering Linacs (ERL2005) was held at Jefferson Laboratory, March 20 to 23, 2005. A wide range of ERL-related topics were presented and discussed in several working groups with Working Group 1 concentrated upon the physics and technology issues for DC, superconducting RF (SRF) and normal conducting RF (NCRF) guns. This paper summarizes the NCRF gun talks and reviews the status of NCRF gun technology. It begins with the presentations made on the subject of low-frequency, high-duty factor guns most appropriate for ERLs. One such gun at 433MHz was demonstrated at 25%DF in 1992, while the CW and much improved version is currently being constructed at 700MHz for LANL. In addition, the idea of combining the NCRF gun with a SRF linac booster was presented and is described in this paper. There was also a talk on high-field guns typically used for SASE free electron lasers. In particular, the DESY coaxial RF feed design provides rotationally symmetric RF fields and greater flexibility in the placement of the focusing magnetic field. While in the LCLS approach, the symmetric fields are obtained with a dual RF feed and racetrack cell shape. Although these guns cannot be operated at high-duty factor, they do produce the best quality beams. With these limitations in mind, a section with material not presented at the workshop has been included in the paper. This work describes a re-entrant approach which may allow NCRF guns to operate with simultaneously increased RF fields and duty factors. And finally, a novel proposal describing a high-duty factor, two-frequency RF gun using a field emission source instead of a laser driven photocathode was also presented.

  15. The SNS Superconducting Linac System

    SciTech Connect

    Claus Rode

    2001-07-01

    The SNS has adopted superconducting RF technology for the high-energy end of its linac. The design uses cavities of {beta} = 0.61 and 0.81 to span the energy region from 186 MeV up to a maximum of 1.3 GeV. Thirty-three of the lower {beta} cavities are contained in 11 cryomodules, and there could be as many as 21 additional cryomodules, each containing four of the higher {beta} cavities, to reach the maximum energy. The design uses a peak surface gradient of 35 MV/m. Each cavity will be driven by a 550 kW klystron. Cryomodules will be connected to the refrigerator by a pair of ''tee'' shape transfer lines. The refrigerator will produce 120 g/sec of refrigeration at 2.1 K, 15 g/sec of liquefaction at 4.5 K, and 8,300 W of 50 K shield refrigeration.

  16. Mechanical Engineering of the Linac for the Spallation Neutron Source

    SciTech Connect

    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.

  17. The DARHT Phase 2 Linac

    NASA Astrophysics Data System (ADS)

    Rutkowski, Henry

    The second phase accelerator for the Dual Axis Hydrodynamic Test facility (DARHT) is designed to provide an electron beam pulse that is 2 microsec long, 2kA, and 20 MeV in particle energy. The injector provides 3.2 MeV so that the linac need only provide 16.8 MeV. The linac is made with two types of induction accelerator cells. The first block of 8 cells have a 14 in. beam pipe compared to 10 in. in the remaining 80 cells. The other principal difference is that the first 8 cells have reduced volt-sec in their induction cores as a result of a larger diameter beam pipe. The cells are designed for very reliable high voltage operation. The insulator is Mycalex. Results from prototype tests are given including results from solenoid measurements. Each cell contains a solenoid for beam transport and a set of x-y correction coils to reduce corkscrew motion. Details of tests to determine RF mode impedances relevant to BBU generation are given. Blocks of cells are separated by "intercells" some of which contain transport solenoids. The intercells provide vacuum pumping stations as well. Issues of alignment and installation are discussed.

  18. Recirculating Linac Accelerators For Future Muon Facilities

    SciTech Connect

    Yves Roblin, Alex Bogacz, Vasiliy Morozov, Kevin Beard

    2012-04-01

    Neutrino Factories (NF) and Muon Colliders (MC) require rapid acceleration of shortlived muons to multi-GeV and TeV energies. A Recirculating Linear Accelerator (RLA) that uses superconducting RF structures can provide exceptionally fast and economical acceleration to the extent that the focusing range of the RLA quadrupoles allows each muon to pass several times through each high-gradient cavity. A new concept of rapidly changing the strength of the RLA focusing quadrupoles as the muons gain energy is being developed to increase the number of passes that each muon will make in the RF cavities, leading to greater cost effectiveness. We discuss the optics and technical requirements for RLA designs, using RF cavities capable of simultaneous acceleration of both m+ and m- species. The design will include the optics for the multi-pass linac and droplet-shaped return arcs.

  19. STATUS OF R AND D ENERGY RECOVERY LINAC AT BROOKHAVEN NATIONAL LABORATORY.

    SciTech Connect

    LITVINENKO,V.; BEN-ZVI, I.; ALDUINO, J.M.; BARTON, D.S.; BEAVIS, D.; BLASKIEWICZ, M.; ET AL.

    2007-06-25

    In this paper we present status and plans for the 20-MeV R&D energy recovery linac (ERL), which is under construction at Collider Accelerator Department at BNL. The facility is based on high current (up to 0.5 A of average current) super-conducting 2.5 MeV RF gun, single-mode super-conducting 5-cell RF linac and about 20-m long return loop with very flexible lattice. The R&D ERL, which is planned for commissioning in early 2009, aims to address many outstanding questions relevant for high current, high brightness energy recovery linacs.

  20. Optics and beam transport in energy recovery linacs

    NASA Astrophysics Data System (ADS)

    Hoffstaetter, Georg H.; Litvinenko, Vladimir; Owen, Hywel

    2006-02-01

    Here, we report on the working group "Optics and Beam Transport" of the 2005 Energy-Recovery-Linac Workshop. This workshop also had working groups on "Electron Guns and Injector Designs", "Superconducting RF and RF Control", and "Synchronization and Diagnostics/Instrumentation". Here, we are concerned with the many different ERL proposals that international laboratories have been working on. Subjects of concern are optics, accelerator design and modeling, stability requirements, designs of the merger that connects the conventional injector linac with the Energy Recovery Linac, longitudinal phase space manipulations to produce short pulses, beam dynamics and limitations by beam instabilities, and computational aspects of space-charge and synchrotron radiation effects. A coarse grain overview is given and reference is made to more detailed articles that were presented in this working group. Subjects are identified where collaborations should be encouraged and areas of future R&D are prioritized.

  1. A hot-spare injector for the APS linac.

    SciTech Connect

    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.

  2. High resolution simulation of beam dynamics in electron linacs for x-ray free electron lasers

    NASA Astrophysics Data System (ADS)

    Qiang, J.; Ryne, R. D.; Venturini, M.; Zholents, A. A.; Pogorelov, I. V.

    2009-10-01

    In this paper we report on large-scale high resolution simulations of beam dynamics in electron linacs for the next-generation x-ray free electron lasers (FELs). We describe key features of a parallel macroparticle simulation code including three-dimensional (3D) space-charge effects, short-range structure wakefields, coherent synchrotron radiation (CSR) wakefields, and treatment of radio-frequency (rf) accelerating cavities using maps obtained from axial field profiles. We present a study of the microbunching instability causing severe electron beam fragmentation in the longitudinal phase space which is a critical issue for future FELs. Using parameters for a proposed FEL linac at Lawrence Berkeley National Laboratory (LBNL), we show that a large number of macroparticles (beyond 100 million) is generally needed to control the numerical macroparticle shot noise and avoid overestimating the microbunching instability. We explore the effect of the longitudinal grid on simulation results. We also study the effect of initial uncorrelated energy spread on the final uncorrelated energy spread of the beam for the FEL linac.

  3. Magnet innovations for linacs

    SciTech Connect

    Halbach, K.

    1986-06-01

    It is possible to produce large magnetic fields at the aperture of permanent magnet quadrupoles, even when the magnetic aperture is very small. That, combined with their compactness, makes permanent magnet quadrupoles very powerful components of small aperture linacs. Results will be presented about past and present work on both fixed and variable strength permanent magnets suitable for use in and around linacs.

  4. CSNS LINAC DESIGN

    SciTech Connect

    FU, S.; FANG, S.; WEI, J.

    2006-08-21

    China Spallation Neutron Source has been approved in principle by the Chinese government. CSNS can provide a beam power of 100kW on the target in the first phase, and then 200kW in the second phase. The accelerator complex of CSNS consists of an H- linac of 81MeV and a rapid cycling synchrotron of 1.6GeV at 25Hz repetition rate. In the second phase, the linac energy will be upgraded to 132MeV and the average current will be doubled. The linac has been designed, and some R&D studies have started under the support from Chinese Academy of Sciences. The linac comprises a H- ion source, an RFQ and a conventional DTL with EMQs. This paper will present our major design results and some progresses in the R&D of the linac.

  5. ESS SC Linac Design Overview

    NASA Astrophysics Data System (ADS)

    Ferdinand, Robin

    2002-12-01

    The ESS project (European Spallation Source) aims to produce high power beams for condensed matter studies. One option consists in having both H+ and H- beams. They have to be accelerated and guided to the different spallation targets. Beam power up to 5 MW at 50 Hz plus 5 MW at 16.2/3 Hz, will be delivered on respectively the Short Pulse Target Station and the Long Pulse Target Station. Two 50 mA H- branches are funnelled with one 100 mA H+ beam at around 20 MeV. A chopper line between two RFQs and DTLs constitutes the H- front end. The H+ front end is composed of one RFQ and one DTL. After the funnel, the two species are transported through the same linac up to 1.334 GeV. This common part is composed of a SDTL and a CCL from 20 to 185 MeV and followed by a SuperConducting Linac (SCL) to reach the final energy. Up to recently (ESS Volume III 1996), a NC version of the linac had been extensively studied and constituted the reference option. However, given the fantastic progresses made on SC technology and the many potential advantages, a SC alternative was developed. We concentrate on this option.

  6. High Current Energy Recovery Linac at BNL

    SciTech Connect

    Vladimir N. Litvinenko; Donald Barton; D. Beavis; Ilan Ben-Zvi; Michael Blaskiewicz; J.M. Brennan; A. Burrill; R. Calaga; P. Cameron; X. Chang; Roger Connolly; D. Gassner; H. Hahn; A. Hershcovitch; H.C. Hseuh; P. Johnson; D. Kayran; J. Kewisch; R. Lambiase; G. McIntyre; W. Meng; T. C. Nehring; A. Nicoletti; D. Pate; J. Rank; T. Roser; T. Russo; J. Scaduto; K. Smith; T. Srinivasan-Rao; N. Williams; K.-C. Wu; Vitaly Yakimenko; K. Yip; A. Zaltsman; Y. Zhao; H. Bluem; A. Burger; Mike Cole; A. Favale; D. Holmes; John Rathke; Tom Schultheiss; A. Todd; J. Delayen; W. Funk; L. Phillips; Joe Preble

    2004-08-01

    We present the design, the parameters of a small test Energy Recovery Linac (ERL) facility, which is under construction at Collider-Accelerator Department, BNL. This R&D facility has goals to demonstrate CW operation of ERL with average beam current in the range of 0.1 - 1 ampere, combined with very high efficiency of energy recovery. A possibility for future up-grade to a two-pass ERL is considered. The heart of the facility is a 5-cell 700 MHz super-conducting RF linac with HOM damping. Flexible lattice of ERL provides a test-bed for testing issues of transverse and longitudinal instabilities and diagnostics of intense CW e-beam. ERL is also perfectly suited for a far-IR FEL. We present the status and our plans for construction and commissioning of this facility.

  7. The source development lab linac at BNL

    SciTech Connect

    Graves, W.S.; Johnson, E.D.; Raubenheimer, T.O.

    1996-12-01

    A 210 MeV SLAC-type electron linac is currently under construction at BNL as part of the Source Development Laboratory. A 1.6 cell RF photoinjector is employed as the high brightness electron source which is excited by a frequency tripled Titanium:Sapphire laser. This linac will be used for several source development projects including a short bunch storage ring, and a series of FEL experiments based on the 10 m long NISUS undulator. The FEL will be operated as either a SASE or seeded beam device using the Ti:Sapp laser. For the seeded beam experiments; direct amplification, harmonic generation, and chirped pulse amplification modes will be studied, spanning an output wavelength range from 900 nm down to 100 nm. This paper presents the project`s design parameters and results of recent modeling using the PARMELA and MAD simulation codes.

  8. HIGH CURRENT ENERGY RECOVERY LINAC AT BNL.

    SciTech Connect

    LITVINENKO,V.N.; BEN-ZVI,I.; BARTON,D.S.; ET AL.

    2005-05-16

    We present the design and parameters of an energy recovery linac (ERL) facility, which is under construction in the Collider-Accelerator Department at BNL. This R&D facility has the goal of demonstrating CW operation of an ERL with an average beam current in the range of 0.1-1 ampere and with very high efficiency of energy recovery. The possibility of a future upgrade to a two-pass ERL is also being considered. The heart of the facility is a 5-cell 703.75 MHz super-conducting RF linac with strong Higher Order Mode (HOM) damping. The flexible lattice of the ERL provides a test-bed for exploring issues of transverse and longitudinal instabilities and diagnostics of intense CW electron beams. This ERL is also perfectly suited for a far-IR FEL. We present the status and plans for construction and commissioning of this facility.

  9. Linac Coherent Light Source (LCLS) at 2--4 nm using the SLAC linac

    SciTech Connect

    Seeman, J.T.; Bane, K.; Boyce, R.; Loew, G.; Morton, P.; Nuhn, H.D.; Paterson, J.; Pianetta, P.; Raubenheimer, T.; Tatchyn, R.; Vylet, V.; Winick, H.; Pellegrini, C.; Rosenzweig, J.; Travish, G.; Prosnitz, D.; Scharlemann, E.T.; Halbach, K.; Kim, K.J.; Xie, M.

    1993-08-01

    The authors describe the possible use of the SLAC linac to drive a unique, powerful, short wavelength Linac Coherent Light Source (LCLS). Using the FEL principle, lasing is achieved in a single pass of a high peak current electron beam through a long undulator by self-amplified-spontaneous-emission (SASE). The main components are a high-brightness electron RF gun with a photocathode, two electron bunch length compressors, the existing SLAC linac, beam diagnostics, and a long undulator combined with a FODO quadrupole focusing system. The RF gun, to be installed about 1 km from the end of the SLAC linac, would produce a single bunch of 6 x 10{sup 9} electrons with an invariant emittance of about 3 mm-mrad and a bunch length of about 500 {mu}m. That bunch is then accelerated to 100 MeV and compressed to a length of about 200 {mu}m. The main SLAC linac accelerates the bunch to 2 GeV were a second bunch compressor reduces the length to 30--40 {mu}m and produces a peak current of 2--3 kA. The bunch is then accelerated to 7--8 GeV and transported to a 50--70 m long undulator. Using electrons below 8 GeV, the undulator could operate at wavelengths down to 2 nm, producing about 10 GW peak power in sub-ps light pulses. At a linac repetition rate of 120 Hz, the average power is about 1 W. Linac operation at lower beam energies provides longer wavelength radiation. After the undulator, the beam is deposited in a dump. The LCLS light pulses are then distributed to multiple user stations using grazing incident mirrors. Length compression, emittance control, phase stability, FEL design criteria, and parameter tolerances are discussed. A demonstration experiment is also described which uses the SLAC linac and (possibly) the PALADIN undulator to study SASE to power saturation at wavelengths of 40--360 nm.

  10. Review of induction LINACS

    SciTech Connect

    Faltens, A.; Keefe, D.

    1981-10-01

    There has been a recent upsurge of activity in the field of induction linacs, with several new machines becoming operational and others in the design stages. The performance levels of electron machines have reached 10's of kiloamps of current and will soon reach 10's of MeV's of energy. Acceleration of ion current has been demonstrated, and the study of a 10 GeV heavy ion induction linac for ICF continues. The operating principles of induction linacs are reviewed with the emphasis on design choices which are important for increasing the maximum beam currents.

  11. Design of 250-MW CW RF system for APT

    SciTech Connect

    Rees, D.

    1997-09-01

    The design for the RF systems for the APT (Accelerator Production of Tritium) proton linac will be presented. The linac produces a continuous beam power of 130 MW at 1300 MeV with the installed capability to produce up to a 170 MW beam at 1700 MeV. The linac is comprised of a 350 MHz RFQ to 7 MeV followed in sequence by a 700 MHz coupled-cavity drift tube linac, coupled-cavity linac, and superconducting (SC) linac to 1700 MeV. At the 1700 MeV, 100 mA level the linac requires 213 MW of continuous-wave (CW) RF power. This power will be supplied by klystrons with a nominal output power of 1.0 MW. 237 kystrons are required with all but three of these klystrons operating at 700 MHz. The klystron count includes redundancy provisions that will be described which allow the RF systems to meet an operational availability in excess of 95 percent. The approach to achieve this redundancy will be presented for both the normal conducting (NC) and SC accelerators. Because of the large amount of CW RF power required for the APT linac, efficiency is very important to minimize operating cost. Operation and the RF system design, including in-progress advanced technology developments which improve efficiency, will be discussed. RF system performance will also be predicted. Because of the simultaneous pressures to increase RF system reliability, reduce tunnel envelope, and minimize RF system cost, the design of the RF vacuum windows has become an important issue. The power from a klystron will be divided into four equal parts to minimize the stress on the RF vacuum windows. Even with this reduction, the RF power level at the window is at the upper boundary of the power levels employed at other CW accelerator facilities. The design of a 350 MHz, coaxial vacuum window will be presented as well as test results and high power conditioning profiles. The transmission of 950 kW, CW, power through this window has been demonstrated with only minimal high power conditioning.

  12. SC driver linac for a rare isotope facility.

    SciTech Connect

    Shepard, K. W.; Delayen, J. R.; Lyneis, C. M.; Nolen, J.; Ostroumov, P.; Staples, J. W.; Brawley, J.; Hovater, C.; Kedzie, M.; Kelly, M. P.; Mammosser, J.; Piller, C.; Portillo, M.

    1999-12-10

    An ion linac formed of superconducting rf cavities can provide a multi-beam driver accelerator for the production of nuclei far from stability. A multi-beam driver supports a wide variety of production reactions and methods. This paper outlines a concept for a 1.3 GV linac capable of delivering several hundred kilowatts of uranium beam at an energy of 400 MeV per nucleon. The linac would accelerate the full mass range of ions, and provide higher velocities for the lighter ions, for example 730 MeV for protons. The accelerator will consist of an ECR ion source injecting a normally conducting RFQ and four short IH structures, then feeding an array of more than 400 superconducting cavities of six different types, which range in frequency from 58 to 700 MHz. A novel feature of the linac is the acceleration of beams containing more than one charge state through portions of the linac, in order to maximize beam current for the heavier ions. Such operation is made feasible by the large transverse and longitudinal acceptance provided by the large aperture and high gradient which are characteristic of superconducting rf cavities.

  13. Ion bombardment in RF photoguns

    SciTech Connect

    Pozdeyev,E.; Kayran, D.; Litvinenko, V. N.

    2009-05-04

    A linac-ring eRHIC design requires a high-intensity CW source of polarized electrons. An SRF gun is viable option that can deliver the required beam. Numerical simulations presented elsewhere have shown that ion bombardment can occur in an RF gun, possibly limiting lifetime of a NEA GaAs cathode. In this paper, we analytically solve the equations of motion of ions in an RF gun using the ponderomotive potential of the Rf field. We apply the method to the BNL 1/2-cell SRF photogun and demonstrate that a significant portion of ions produced in the gun can reach the cathode if no special precautions are taken. Also, the paper discusses possible mitigation techniques that can reduce the rate of ion bombardment.

  14. An overview of LINAC ion sources

    SciTech Connect

    Keller, Roderich

    2008-01-01

    This paper discusses ion sources used in high-duty-factor proton and H{sup -} Linacs as well as in accelerators utilizing multi-charged heavy ions, mostly for nuclear physics applications. The included types are Electron Cyclotron Resonance (ECR) sources as well as filament and rf driven multicusp sources. The paper does not strive to attain encyclopedic character but rather to highlight major lines of development, peak performance parameters and type-specific limitations and problems of these sources. The main technical aspects being discussed are particle feed, plasma generation and ion production by discharges, and plasma confinement.

  15. RF-Based Accelerators for HEDP Research

    SciTech Connect

    Staples, John W.; Sessler, Andrew; Keller, Roderich; Ostroumov,Petr; Chou, Weiren

    2005-05-09

    Accelerator-driven High-Energy Density Physics (HEDP) experiments require typically 1 nanosecond, 1 microcoulomb pulses of mass 20 ions accelerated to several MeV to produce eV-level excitations in thin targets, the warm dense matter regime. Traditionally the province of induction linacs, RF-based acceleration may be a viable alternative with recent breakthroughs in accelerating structures and high-field compact superconducting solenoids. A reference design for an RF-based accelerator for HEDP research is presented using 15 T solenoids and multiple-gap RF structures configured with multiple parallel beams combined at the target. The beam is ballistically compressed with an induction linac core providing the necessary energy sweep and injected into a plasma-neutralized drift compression channel resulting in a 1 mm radius beam spot 1 nanosecond long at a thin foil or low-density target.

  16. Billion particle linac simulations for future light sources

    SciTech Connect

    Ryne, R. D.; Venturini, M.; Zholents, A. A.; Qiang, J.

    2008-09-25

    In this paper we report on multi-physics, multi-billion macroparticle simulation of beam transport in a free electron laser (FEL) linac for future light source applications. The simulation includes a self-consistent calculation of 3D space-charge effects, short-range geometry wakefields, longitudinal coherent synchrotron radiation (CSR) wakefields, and detailed modeling of RF acceleration and focusing. We discuss the need for and the challenges associated with such large-scale simulation. Applications to the study of the microbunching instability in an FEL linac are also presented.

  17. Diagnostics For Recirculating And Energy Recovered Linacs

    SciTech Connect

    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.

  18. The upgrade of the Brookhaven Linac Isotope Producer (BLIP) and the BNL Linac

    SciTech Connect

    Mausner, L.F.; Alessi, J.G.

    1996-12-31

    An upgrade project was recently completed on the 200 MeV H{sup -} linac and the Brookhaven Linac Isotope Producer (BLIP) in order to improve radioisotope production capacity and reliability. The average beam current has increased from 60 {mu}A to 150 {mu}A. The increased average current is the result of increases in peak current, from 25 mA to 37 mA, pulse repetition rate, from 5 to 7.5 Hz, and pulse width, from 500 to 530 ps. To achieve this performance the 35 keV, 750 keV and 200 MeV beam transport were improved, the RF transmission lines and RF power supplies replaced. Improvements to the linac control system, and the optics and vacuum system of the 200 MeV transport were implemented. A BLIP the target cooling system was upgraded to 35 kW and automated, the targets, and target mechanical systems replaced with a more robust design, and the control system upgraded. With these enhancements BLIP is ready to address the lack of availability of accelerator produced medical and research isotopes.

  19. Energy Recovery Linacs for Light Source Applications

    SciTech Connect

    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.

  20. Permanent-magnet quadrupoles in RFQ Linacs

    SciTech Connect

    Lysenko, W.P.; Wang, T.F.

    1985-10-01

    We investigated the possibility of increasing the current-carrying capability of radio-frequency quadrupole (RFQ) linear accelerators by adding permanentmagnet quadrupole (PMQ) focusing to the existing transverse focusing provided by the rf electric field. Increased transverse focusing would also allow shortening RFQ linacs by permitting a larger accelerating gradient, which is normally accompanied by an undesirable increased transverse rf defocusing effect. We found that PMQs were not helpful in increasing the transverse focusing strength in an RFQ. This conclusion was reached after some particle tracing simulations and some analytical calculations. In our parameter regime, the addition of the magnets increases the betatron frequency but does not result in improved focusing because the increased flutter more than offsets the gain from the increased betatron frequency.

  1. RF/Microwave properties and applications of directly assembled nanotubes and nanowires: LDRD project 102662 final report.

    SciTech Connect

    Mayer, Theresa (The Pennyslvania State University, University Park, PA 16802); Vallett, Aaron (The Pennyslvania State University, University Park, PA 16802); Lee, Mark; Shaner, Eric Arthur; Jones, Frank E.; Talin, Albert Alec; Highstrete, Clark

    2006-11-01

    LDRD Project 102662 provided support to pursue experiments aimed at measuring the basic electrodynamic response and possible applications of carbon nanotubes and silicon nanowires at radiofrequency to microwave frequencies, approximately 0.01 to 50 GHz. Under this project, a method was developed to integrate these nanomaterials onto high-frequency compatible co-planar waveguides. The complex reflection and transmission coefficients of the nanomaterials was studied as a function of frequency. From these data, the high-frequency loss characteristics of the nanomaterials were deduced. These data are useful to predict frequency dependence and power dissipation characteristics in new rf/microwave devices incorporating new nanomaterials.

  2. R&D ERL: Low level RF

    SciTech Connect

    Smith, K.

    2010-01-15

    A superconducting RF (SRF) Energy Recovery Linac (ERL) is currently under development at the Collider-Accelerator Department (C-AD) at Brookhaven National Laboratory (BNL). The major components from an RF perspective are (a) a 5-cell SRF ERL cavity, (b) an SRF photocathode electron gun, and (c) a drive laser for the photocathode gun. Each of these RF subsystems has its own set of RF performance requirements, as well as common requirements for ensuring correct synchronism between them. A low level RF (LLRF) control system is currently under development, which seeks to leverage both technology and experience gained from the recently commissioned RHIC LLRF system upgrade. This note will review the LLRF system requirements and describe the system to be installed at the ERL.

  3. Rf System for the NLCTA

    SciTech Connect

    Wang, J.W.; Adolphsen, C.; Eichner, J.; Fuller, R.W.; Gold, S.L.; Hanna, S.M.; Hoag, H.A.; Holmes, S.G.; Koontz, R.F.; Lavine, Theodore L.; Loewen, R.J.; Miller, R.H.; Nantista, C.D.; Pope, R.; Rifkin, J.; Ruth, R.D.; Tantawi, S.G.; Vlieks, A.E.; Wilson, Z.; Yeremian, A.; /SLAC

    2011-08-26

    This paper describes an X-Band RF system for the Next Linear Collider Test Accelerator. The RF system consists of a 90 MeV injector and a 540 MeV linac. The main components of the injector are two low-Q single-cavity prebunchers and two 0.9-m-long detuned accelerator sections. The linac system consists of six 1.8-m-long detuned and damped detuned accelerator sections powered in pairs. The rf power generation, compression, delivery, distribution and measurement systems consist of klystrons, SLEDII energy compression systems, rectangular waveguides, magic-T's, and directional couplers. The phase and amplitude for each prebuncher is adjusted via a magic-T type phase shifter/attenuator. Correct phasing between the two 0.9 m accelerator sections is obtained by properly aligning the sections and adjusting two squeeze type phase shifters. Bunch phase and bunch length can be monitored with special microwave cavities and measurement systems. The design, fabrication, microwave measurement, calibration, and operation of the sub-systems and their components are briefly presented.

  4. Development of a high-current microwave ion source for proton linac application systems

    NASA Astrophysics Data System (ADS)

    Tanaka, M.; Hara, S.; Hae, T.; Iga, T.; Saitou, K.; Amemiya, K.; Hiramoto, K.; Kakiuchi, S.

    2004-05-01

    A microwave hydrogen ion source was developed to improve reliability, and to increase operation time of proton linac application systems. The ion source needs no filament in the discharge chamber, which leads to better reliability and less maintenance time. The developed source produced a maximum hydrogen ion beam current of 70 mA (high current density of 360 mA/cm2, beam energy of 30 keV) with a 5 mm diam extraction aperture and 1.2 kW microwave power. The proton fraction was increased with an increase in rf power and reached around 90% at 1 kW. Measured 90% beam normalized emittance was 0.4 π mm mrad. Rise times of rf power and beam current to 90% of the final values were about 30 and 35 μs, respectively, at a pulse operation mode with 400 μs pulse width and 100 Hz repetition rate. The dynamic range of beam currents was enlarged (3-63 mA) in the pulse mode with a modified rf wave form to assist ignition of microwave discharge. These performance parameters will be desirable for pulse operation accelerator applications like proton therapy systems. A long time operation stability (150 h) was confirmed with a beam current of 51 mA; change in the current was 2%.

  5. Beam Dynamics Studies for the First Muon Linac of the Neutrino Factory

    SciTech Connect

    C. Bontoiu,M. Aslaninejad,J. Pozimski,Alex Bogacz

    2010-05-01

    Within the Neutrino Factory Project the muon acceleration process involves a complex chain of accelerators including a (single-pass) linac, two recirculating linacs and an FFAG. The linac consists of RF cavities and iron shielded solenoids for transverse focusing and has been previously designed relying on idealized field models. However, to predict accurately the transport and acceleration of a high emittance 30 cm wide beam with 10 % energy spread requires detailed knowledge of fringe field distributions. This article presents results of the front-to-end tracking of the muon beam through numerically simulated realistic field distributions for the shielded solenoids and the RF fields. Real and phase space evolution of the beam has been studied along the linac and the results are presented and discussed.

  6. Features Of The J-PARC Linac

    SciTech Connect

    Kobayashi, Tetsuya

    2011-06-01

    Japan Proton Accelerator Research Complex (J-PARC) will be one of the highest intensity proton accelerators in the world aiming to realize 1 MW class of the beam power. The accelerator consists of a 400-MeV linac, a 3-GeV rapid-cycling synchrotron (RCS) and a main ring synchrotron (MR), and the accelerated beam is applied to several experimental facilities. The linac, which is the injector for the RCS, has about 50 cavity modules to accelerate the beam up to 400 MeV. The acceleration field error in all of them should be within {+-}1% in amplitude and {+-}1 degree in phase because the momentum spread of the RCS injection beam is required to be within 0.1%. For the cavity field stabilization, a high-stable optical signal distribution system is used as the RF reference, and sophisticated digital feedback and feed-forward system is working well in the low level RF control system. Consequently the providing beam to the RCS is very stable, and the beam commissioning and the experiments of the application facilities have been progressed steadily.

  7. Progress in Induction Linacs

    SciTech Connect

    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.

  8. Special SLC linac developments

    SciTech Connect

    Seeman, J.T.; Sheppard, J.C.

    1986-04-01

    The linac of the SLAC Linear Collider (SLC) is required to accelerate several intense electron and positron bunches to high energy while maintaining their small transverse dimensions and energy spectra. Many of the linac systems have been upgraded to the new stringent SLC design criteria. The remaining systems will be completed in the summer of 1986. Special instruments and controls have been developed to monitor and manipulate these small but potent beams. A brief review of the SLC requirements is given. A broad survey of the recent development is made encompassing longitudinal and transverse wakefield reductions, Landau damping, energy and position feedback systems, beam diagnostic and beam current fluctuations.

  9. Heavy-ion acceleration with a superconducting linac

    SciTech Connect

    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. Conceptual design of a linac-stretcher ring to obtain a 2-GeV continuous electron beam

    SciTech Connect

    Cho, Y.; Holt, R.J.; Jackson, H.E.; Khoe, T.K.; Mavrogenes, G.S.

    1981-01-01

    In order to obtain a high duty factor, > 100 ..mu..A 2-GeV electron beam, we have designed a linac-stretcher ring system. The system is an attractive option because it draws heavily on the existing accelerator technology. The linac-stretcher ring consists of a 2-GeV SLAC-type pulsed linac which injects into a storage ring. In between linac pulses, the stored electron beam is to extract resonantly. This design differs from those discussed recently in several important respects. The storage ring includes an RF system whose purpose is to control the beam orbit and rate of extraction from the ring. With an RF system in the ring, the injection scheme consists of a few turns of synchronous transfers of beam between the linac and storage ring.

  11. The design for the LCLS RF photoinjector

    NASA Astrophysics Data System (ADS)

    Alley, R.; Bharadwaj, V.; Clendenin, J.; Emma, P.; Fisher, A.; Frisch, J.; Kotseroglou, T.; Miller, R. H.; Palmer, D. T.; Schmerge, J.; Sheppard, J. C.; Woodley, M.; Yeremian, A. D.; Rosenzweig, J.; Meyerhofer, D. D.; Serafini, L.

    1999-06-01

    We report on the design of the RF photoinjector of the Linac Coherent Light Source. The RF photoinjector is required to produce a single 150 MeV bunch of ˜1 nC and ˜100 A peak current at a repetition rate of 120 Hz with a normalized rms transverse emittance of ˜1 π mm-mrad. The design employs a 1.6-cell S-band RF gun with an optical spot size at the cathode of a radius of ˜1 mm and a pulse duration with an rms sigma of ˜3 ps. The peak RF field at the cathode is 150 MV/m with extraction 57° ahead of the RF peak. A solenoidal field near the cathode allows the compensation of the initial emittance growth by the end of the injection linac. Spatial and temporal shaping of the laser pulse striking the cathode will reduce the compensated emittance even further. Also, to minimize the contribution of the thermal emittance from the cathode surface, while at the same time optimizing the quantum efficiency, the laser wavelength for a Cu cathode should be tunable around 260 nm. Following the injection linac the geometric emittance simply damps linearly with energy growth. PARMELA simulations show that this design will produce the desired normalized emittance, which is about a factor of two lower than has been achieved to date in other systems. In addition to low emittance, we also aim for laser amplitude stability of 1% in the UV and a timing jitter in the electron beam of 0.5 ps rms, which will lead to less than 10% beam intensity fluctuation after the electron bunch is compressed in the main linac.

  12. Linac4 H⁻ ion sources.

    PubMed

    Lettry, J; Aguglia, D; Alessi, J; Andersson, P; Bertolo, S; Briefi, S; Butterworth, A; Coutron, Y; Dallocchio, A; David, N; Chaudet, E; Faircloth, D; Fantz, U; Fink, D A; Garlasche, M; Grudiev, A; Guida, R; Hansen, J; Haase, M; Hatayama, A; Jones, A; Koszar, I; Lallement, J-B; Lombardi, A M; Machado, C; Mastrostefano, C; Mathot, S; Mattei, S; Moyret, P; Nisbet, D; Nishida, K; O'Neil, M; Paoluzzi, M; Scrivens, R; Shibata, T; Steyaert, D; Thaus, N; Voulgarakis, G

    2016-02-01

    CERN's 160 MeV H(-) linear accelerator (Linac4) is a key constituent of the injector chain upgrade of the Large Hadron Collider that is being installed and commissioned. A cesiated surface ion source prototype is being tested and has delivered a beam intensity of 45 mA within an emittance of 0.3 π ⋅ mm ⋅ mrad. The optimum ratio of the co-extracted electron- to ion-current is below 1 and the best production efficiency, defined as the ratio of the beam current to the 2 MHz RF-power transmitted to the plasma, reached 1.1 mA/kW. The H(-) source prototype and the first tests of the new ion source optics, electron-dump, and front end developed to minimize the beam emittance are presented. A temperature regulated magnetron H(-) source developed by the Brookhaven National Laboratory was built at CERN. The first tests of the magnetron operated at 0.8 Hz repetition rate are described. PMID:26932021

  13. Linac4 H- ion sources

    NASA Astrophysics Data System (ADS)

    Lettry, J.; Aguglia, D.; Alessi, J.; Andersson, P.; Bertolo, S.; Briefi, S.; Butterworth, A.; Coutron, Y.; Dallocchio, A.; David, N.; Chaudet, E.; Faircloth, D.; Fantz, U.; Fink, D. A.; Garlasche, M.; Grudiev, A.; Guida, R.; Hansen, J.; Haase, M.; Hatayama, A.; Jones, A.; Koszar, I.; Lallement, J.-B.; Lombardi, A. M.; Machado, C.; Mastrostefano, C.; Mathot, S.; Mattei, S.; Moyret, P.; Nisbet, D.; Nishida, K.; O'Neil, M.; Paoluzzi, M.; Scrivens, R.; Shibata, T.; Steyaert, D.; Thaus, N.; Voulgarakis, G.

    2016-02-01

    CERN's 160 MeV H- linear accelerator (Linac4) is a key constituent of the injector chain upgrade of the Large Hadron Collider that is being installed and commissioned. A cesiated surface ion source prototype is being tested and has delivered a beam intensity of 45 mA within an emittance of 0.3 π ṡ mm ṡ mrad. The optimum ratio of the co-extracted electron- to ion-current is below 1 and the best production efficiency, defined as the ratio of the beam current to the 2 MHz RF-power transmitted to the plasma, reached 1.1 mA/kW. The H- source prototype and the first tests of the new ion source optics, electron-dump, and front end developed to minimize the beam emittance are presented. A temperature regulated magnetron H- source developed by the Brookhaven National Laboratory was built at CERN. The first tests of the magnetron operated at 0.8 Hz repetition rate are described.

  14. Cavities and Cryomodules for the RIA Driver Linac

    SciTech Connect

    Fuerst, J.D.; Shepard, K.W.; Kedzie, M.; Kelly, M.P.

    2004-06-23

    We describe cavities, cryomodules, and associated subsystem concepts for the Rare Isotope Accelerator (RIA) driver linac baseline design. Some alternative concepts are also presented. Beams from protons to uranium are accelerated with superconducting RF cavities operating from 57.5 MHz to 805 MHz. Substantial cost reduction over the baseline design may be achieved by replacing three classes of elliptical cell structures operating at 2 K by two classes of three-spoke drift tube structures. Cavity count and tunnel length are reduced while efficient cooling at 4.5 K for all linac structures may be possible. Issues include RF power requirements, microphonics, clean handling techniques, separate cavity and insulating vacuum systems, and heat load.

  15. Overview and Status Update of the Fermilab HINS Linac R&D Program

    SciTech Connect

    Webber, R.C.; Apollinari, G.; /Fermilab

    2009-05-01

    The Fermilab High Intensity Neutrino Source (HINS) Linac R&D program is continuing efforts to construct a first-of-a-kind superconducting H{sup -} linac. The goal of the HINS linac is to demonstrate, for the first time, acceleration of high intensity beam with superconducting spoke cavities, control of beam halo growth by use of solenoidal focusing optics throughout, and operation of many cavities from a single high-power RF source for acceleration of non-relativistic particles. The HINS effort is relevant to any future high brightness, high intensity linac and, in particular, to the linac proposed as part of Fermilab Project X to serve the next generation of neutrino physics and future muon storage ring/collider experiments. This paper updates the technical status of the various components being developed, built, and commissioned as a part of HINS and presents the outlook for the HINS program.

  16. RF MEMS Based Reconfigurable Antennas

    NASA Technical Reports Server (NTRS)

    Simons, Rainee N.

    2004-01-01

    The presentation will first of all address the advantages of RF MEMS circuit in antenna applications and also the need for electronically reconfigurable antennas. Next, discuss some of the recent examples of RF MEMS based reconfigurable microstrip antennas. Finally, conclude the talk with a summary of MEMS antenna performance.

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

    SciTech Connect

    Sukhanov, A.; Lunin, A.; Yakovlev, V.; Gonin, I.; Khabiboulline, T.; Saini, A.; Solyak, N.; Yostrikov, A.

    2012-09-01

    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.

  18. Literature Review on LINACs and FFAGs for Hadron Therapy

    NASA Astrophysics Data System (ADS)

    Verdú-Andrés, Silvia; Amaldi, Ugo; Faus-Golfe, Ángeles

    The document summarizes the recent papers, presentations and other public information on Radio-Frequency (RF) Linear Accelerators (linacs) and Fixed-Field Alternating-Gradient (FFAG) accelerators for hadron therapy. The main focus is on technical aspects of these accelerators. This report intends to provide a general overview of the state-of-the-art in those accelerators which could be used in short and middle-term for treating cancer.

  19. Development of a commissioning plan for the APT linac

    SciTech Connect

    Funk, L.W.; Crandall, K.R.; Gilpatrick, J.D.; Gray, E.R.; Regan, A.H.; Rohlev, A.; Rybarcyk, L.J.; Wangler, T.P.

    1998-12-31

    The Accelerator Production of Tritium (APT) facility is based on a linac which incorporates both normal-conducting and superconducting RF technology and accelerates a 100-mA cw proton beam to an energy of 1,030 MeV or higher, depending on the desired production rate. Commissioning plans to achieve full power operation with minimum beam-induced activation of components have been evolving. This paper presents the main issues and the basic approaches that are now being discussed.

  20. Design and Start-to-End Simulation of an X-Band RF Driven Hard X-Ray FEL with LCLS Injector

    SciTech Connect

    Sun, Yipeng; /SLAC

    2012-08-20

    In this note, it is briefly discussed the accelerator design and start-to-end 3D macro particles simulation (using ELEGANT and GENESIS) of an X-band RF driven hard X-ray FEL with LCLS injector. A preliminary design and LiTrack 1D simulation studies were presented before in an older publication [1]. In numerical simulations this X-band RF driven hard X-ray FEL achieves/exceeds LCLS-like performance in a much shorter overall length of 350 m, compared with 1200 m in the LCLS case. One key feature of this design is that it may achieve a higher final beam current of 5 kA plus a uniform energy profile, mainly due to the employment of stronger longitudinal wake fields in the last X-band RF linac [2].

  1. Recirculated and Energy Recovered Linacs

    SciTech Connect

    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.

  2. A Linac Simulation Code for Macro-Particles Tracking and Steering Algorithm Implementation

    SciTech Connect

    sun, yipeng

    2012-05-03

    In this paper, a linac simulation code written in Fortran90 is presented and several simulation examples are given. This code is optimized to implement linac alignment and steering algorithms, and evaluate the accelerator errors such as RF phase and acceleration gradient, quadrupole and BPM misalignment. It can track a single particle or a bunch of particles through normal linear accelerator elements such as quadrupole, RF cavity, dipole corrector and drift space. One-to-one steering algorithm and a global alignment (steering) algorithm are implemented in this code.

  3. Optimizing cavity gradients in pulsed Linacs using the cavity transient response

    SciTech Connect

    Cancelo, G.; Vignoni, A.; /Fermilab

    2008-10-01

    In order to achieve beam intensity and luminosity requirements, pulsed LINAC accelerators have stringent requirements on the amplitude and phase of RF cavity gradients. The amplitude and phase of the RF cavity gradients under heavy beam loading must be kept constant within a fraction of a % and a fraction of a degree respectively. The current paper develops a theoretical method to calculate RF parameters that optimize cavity gradients in multi cavity RF units under heavy beam loading. The theory is tested with a simulation example.

  4. High-gradient C-band linac for a compact x-ray free-electron laser facility

    NASA Astrophysics Data System (ADS)

    Inagaki, T.; Kondo, C.; Maesaka, H.; Ohshima, T.; Otake, Y.; Sakurai, T.; Shirasawa, K.; Shintake, T.

    2014-08-01

    An electron linac using a C-band rf frequency, 5.712 GHz, has enabled us to obtain an acceleration gradient of more than 35 MV/m reliably. A C-band accelerator system has been developed and constructed for the compact x-ray FEL facility, SACLA, in order to fit within the available site length at SPring-8, and to reduce construction costs. An accelerator unit consists of two 1.8 m-long accelerator structures, a cavity-type rf pulse compressor and a 50 MW pulsed klystron. In order to achieve a compact rf source and to obtain extremely stable rf fields in the accelerator structures, an oil-filled, high-voltage pulse modulator combined with an extremely stable, inverter-type, high voltage charger was developed. SACLA uses 64 sets of these accelerator units in order to achieve a final beam energy of 8.5 GeV. After rf conditioning for 1 700 hours, the maximum acceleration gradient achieved was 38 MV/m. The typical trip rate for each accelerator unit at 35 MV/m and 30 pps is about once per day. Dark current from the accelerator structures is less than 5 pC, which causes a negligible effect on the beam monitors. The phase and amplitude stability of the rf fields were measured to be 0.03 degree and 0.01% rms, respectively, which is sufficient for the XFEL operation of SACLA. Since the first beam commissioning in 2011, the C-band accelerator has demonstrated fairly stable performance under continuous operation for 20 000 hours.

  5. Vacuum system for superconducting LINAC at TIFR

    NASA Astrophysics Data System (ADS)

    Pillay, R. G.

    2008-05-01

    The superconducting heavy ion LINAC booster at the TIFR-BARC facility has been operational. Seven super conducting cryostats containing 4 quarter wave resonators each along with beam lines, bending magnets, switching magnet, diagnostics and vacuum system have been commissioned. The heart of the cryogenic system for the heavy ion superconducting LINAC booster is a custom-built liquid helium refrigerator made by Linde Kryotechnik, Switzerland. The Refrigerator is rated for 300 Watts at 4.5 K with a dual JT (Joule-Thomson valve) at the final cooling stage, which allows simultaneous connections to the cryogenic loads (the LINAC module cryostats) and to a liquid helium storage dewar (1000 litres). The two-phase helium at 4.5 K produced at the JT stage in the refrigerator is delivered to the cryostats through a cryogenic distribution system. The cryogenic distribution system for the LINAC is designed to deliver both liquid helium and liquid nitrogen to the cryostats. The details of UHV system, indigenously developed beam line components, pumps and module cryostats will be presented.

  6. Concepts and Applications of Energy Recovery Linacs (ERLs)

    SciTech Connect

    Gruner, Sol M.

    2004-05-12

    Energy Recovery Linacs are being explored as next generation synchrotron light sources. The fundamental x-ray beam properties from storage ring sources, such as the source size, brilliance, and pulse duration are limited by the dynamic equilibrium characteristic of the magnetic lattice that is the storage ring. Importantly, the characteristic equilibration time is long, involving thousands of orbits around the ring. Advances in laser-driven photoelectron sources allow the generation of electron bunches with superior properties for synchrotron radiation. ERLs preserve these properties by acceleration with a superconducting linac, followed by transport through a return loop hosting insertion devices, similar to that of a 3rd generation storage ring. The loop returns bunches to the linac 180 deg. out of accelerating phase for deceleration through the linac and disposal. Thus, the electron beam energy is recycled back into the linac RF field for acceleration of new bunches and the equilibrium degradation of bunches never occurs. The superior projected properties of ERLs beams include extraordinary brilliance and small source size, with concomitant high transverse coherence, x-ray pulse durations down to {approx}100 femtoseconds, and flexibility of operation. ERL projects are summarized. ERLs will be capable of hosting practically all experiments now being carried out at storage rings while also enabling new types of experiments.

  7. ILC RF System R and D

    SciTech Connect

    Adolphsen, Chris; /SLAC

    2012-07-03

    The Linac Group at SLAC is actively pursuing a broad range of R&D to improve the reliability and reduce the cost of the L-band (1.3 GHz) rf system proposed for the ILC linacs. Current activities include the long-term evaluation of a 120 kV Marx Modulator driving a 10 MW Multi-Beam Klystron, design of a second-generation Marx Modulator, testing of a sheet-beam gun and beam transport system for a klystron, construction of an rf distribution system with remotely-adjustable power tapoffs, and development of a system to combine the power from many klystrons in low-loss circular waveguide where it would be tapped-off periodically to power groups of cavities. This paper surveys progress during the past few years.

  8. Designing focusing solenoids for superconducting RF accelerators

    SciTech Connect

    Davis, G.; Kashikhin, V.V.; Page, T.; Terechkine, I.; Tompkins, J.; Wokas, T.; /Fermilab

    2006-08-01

    The design of a focusing solenoid for use in a superconducting RF linac requires resolving a range of problems with conflicting requirements. Providing the required focusing strength contradicts the goal of minimizing the stray field on the surfaces of adjacent superconducting RF cavities. The requirement of a compact solenoid, able to fit into a gap between cavities, contradicts the need of mechanical support necessary to restrain electromagnetic forces that can result in coil motion and subsequent quenching. In this report we will attempt to address these and other issues arising during the development of focusing solenoids. Some relevant test data will also be presented.

  9. Superconducting RF systems for eRHIC

    SciTech Connect

    Belomestnykh S.; Ben-Zvi, I.; Brutus, J.C.; Hahn, H. et al

    2012-05-20

    The proposed electron-hadron collider eRHIC will consist of a six-pass 30-GeV electron Energy Recovery Linac (ERL) and one of RHIC storage rings operating with energy up to 250 GeV. The collider design extensively utilizes superconducting RF (SRF) technology in both electron and hadron parts. This paper describes various SRF systems, their requirements and parameters.

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

    SciTech Connect

    Belomestnykh, S.; Ben-Zvi, I.; Brutus, J. C.; Litvinenko, V.; McIntosh, P.; Moss, A.; Narayan, G.; Orfin, P.; Pinayev, I.; Rao, T.; Skaritka, J.; Smith, K.; Than, R.; Tuozzolo, J.; Wang, E.; Wheelhouse, A.; Wu, Q.; Xiao, B.; Xin, T.; Xu, W.; Zaltsman, A.

    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

  11. CONCEPTUAL DESIGN OF A CAPTURE RF SYSTEM FOR MUON COLLIDERS.

    SciTech Connect

    ROSE,J.

    2001-06-18

    A conceptual RF System design provides a basis for a more detailed engineering study to explore the technical issues involved in fabricating and testing a capture RF system in a proton-driver target experiment. A large-bore 71 MHz cavity design is detailed which is self-consistent with a proton-driver target experiment at BNL. Analysis of cell to cell coupling in a linac composed of a string of such cavitites is presented.

  12. TRAK_RF - Electromagnetic Field and Charged Particle Simulations in RF Devices

    NASA Astrophysics Data System (ADS)

    Humphries, Stanley; Rees, Daniel

    1997-05-01

    An integrated software system has been developed to model electromagnetic fields and charged particle orbits in high-power RF devices. The primary application is simulation of electron multipactoring in linac vacuum windows for Accelerator Production of Tritium(G. Lawrence, et.al., Conventional and Superconducting RF Linac Design for the APT Project, in Proc. 1996 Int'l. Linear Acc. Conf. (Geneva, 1996), to be published.). The finite-element frequency-domain field solver can determine resonant fields such as cutoff and propagating modes of waveguides and TE(mnp) and TM(mnp) modes of cylindrical structures. In contrast to codes like Superfish, TRAK_RF makes direct determinations of power dissipation and phase shifts resulting ffrom lossy materials and walls. Furthermore, the program can handle scattering solutions, simulating free-space conditions with resistive termination boundary layers. TRAK_RF has advanced particle tracking capabilities to investigate a variety of innovative window designs. The program can simutaneously apply three numerical solutions for electrostatic, magnetostatic and electromagnetic fields on independent conformal triangular meshes. The finite-element method allows an unambiguous determination of particle collisions with material surfaces. It is possible to define up to 32 material types with energy-dependent secondary emission coefficients. TRAK_RF has a versatile automatic mesh generator with an interactive drafting utility for boundary input. Other applications include cavity design, radar and communications, microwave systems, and beam optics in RF accelerators.

  13. RF study and 3-D simulations of a side-coupling thermionic RF-gun

    NASA Astrophysics Data System (ADS)

    Rimjaem, S.; Kusoljariyakul, K.; Thongbai, C.

    2014-02-01

    A thermionic RF-gun for generating ultra-short electron bunches was optimized, developed and used as a source at a linac-based THz radiation research laboratory of the Plasma and Beam Physics Research Facility, Chiang Mai University, Thailand. The RF-gun is a π/2-mode standing wave structure, which consists of two S-band accelerating cells and a side-coupling cavity. The 2856 MHz RF wave is supplied from an S-band klystron to the gun through the waveguide input-port at the cylindrical wall of the second cell. A fraction of the RF power is coupled from the second cell to the first one via a side-coupling cavity. Both the waveguide input-port and the side-coupling cavity lead to an asymmetric geometry of the gun. RF properties and electromagnetic field distributions inside the RF-gun were studied and numerically simulated by using computer codes SUPERFISH 7.19 and CST Microwave Studio 2012©. RF characterizations and tunings of the RF-gun were performed to ensure the reliability of the gun operation. The results from 3D simulations and measurements are compared and discussed in this paper. The influence of asymmetric field distributions inside the RF-gun on the electron beam properties was investigated via 3D beam dynamics simulations. A change in the coupling-plane of the side-coupling cavity is suggested to improve the gun performance.

  14. Superconducting linacs: some recent developments

    SciTech Connect

    Bollinger, L.M.

    1985-01-01

    The paper is a review of superconducting linacs that are of interest for heavy-ion acceleration. Most of the paper is concerned with energy boosters for projectiles from tandem electrostatic accelerators, the only application for which superconducting linacs are now used for heavy-ion acceleration. There is also a brief discussion of the concept of a superconducting injector linac being developed as a replacement of the tandem in a multi-stage acceleration system. Throughout, the emphasis is on the technology of the superconducting linac, including some attention to the relationships between resonator design parameters and accelerator performance characteristics. 21 refs., 14 figs., 3 tabs.

  15. SSC Linac Beam Position Monitor System

    NASA Astrophysics Data System (ADS)

    Aiello, G. Roberto; Jones, Alan A.; Mills, Mark R.

    1994-10-01

    The Superconducting Super Collider (SSC), Linac Beam Position Monitor System is designed to measure beam position and phase. Forty-three monitors will be installed in the Linac and Transfer Line. The position measurement provides information on the transverse beam position in the beam pipe with respect to a mechanical reference. The phase measurement provides information on the difference between the longitudinal phase of the beam and the radio frequency reference signal (rf reference), to be used for phase scanning and time of flight measurement. The system design and the prototypes are complete, and the series is under fabrication. The signals to be processed are extracted from four striplines, down-converted to a convenient intermediate frequency and fed into position and phase electronics. The position electronics is realized with the log-ratio technique, and the phase electronics uses a new digital technique that overcomes most of the problems of existing systems. Both position and phase analog electronics are mounted on identical VXI motherboards, containing analog-to-digital converters (ADC's) and digital circuitry.

  16. SSC Linac Beam Position Monitor System

    SciTech Connect

    Aiello, G.R.; Jones, A.A.; Mills, M.R. )

    1994-10-10

    The Superconducting Super Collider (SSC), Linac Beam Position Monitor System is designed to measure beam position and phase. Forty-three monitors will be installed in the Linac and Transfer Line. The position measurement provides information on the transverse beam position in the beam pipe with respect to a mechanical reference. The phase measurement provides information on the difference between the longitudinal phase of the beam and the radio frequency reference signal (rf reference), to be used for phase scanning and time of flight measurement. The system design and the prototypes are complete, and the series is under fabrication. The signals to be processed are extracted from four striplines, down-converted to a convenient intermediate frequency and fed into position and phase electronics. The position electronics is realized with the log-ratio technique, and the phase electronics uses a new digital technique that overcomes most of the problems of existing systems. Both position and phase analog electronics are mounted on identical VXI motherboards, containing analog-to-digital converters (ADC's) and digital circuitry.

  17. RF System High Power Amplifier Software Conversion at Jefferson Lab

    SciTech Connect

    G. Lahti; H. Dong; T. Seegerger

    2006-10-31

    Jefferson Lab is in the process of converting the RF system from analog RF modules and non-smart high power amplifiers (HPAs) to digital RF modules and smart HPAs. The present analog RF module controls both the RF signal and the non-smart HPA hardware. The new digital RF module will only control the RF signal, so the new HPA must include embedded software. This paper will describe the conversion from a software perspective, including the initial testing, the intermediate mixed system of old and new units, and finally the totally new RF system.

  18. Phase Noise Measurement in PEP II and the Linac

    SciTech Connect

    Getaneh, Mesfin

    2003-09-05

    The Goal of this project is to provide a measurement of the phase of the radio frequency (RF) relative to electron beam traveling down the Stanford Linear Accelerator Center (SLAC). Because the Main Drive Line (MDL) supplies the RF drive and phase reference for the entire accelerator system, the phase accuracy and amount of phase noise present in the MDL are very critical to the functionality of the accelerator. Therefore, a Phase Noise Measurement System was built to measure the phase noise in the liner accelerator (Linac) and PEP II. The system was used to determine the stability of the PEP II RF reference system. In this project a low noise Phase Locked Loop system (PLL) was built to measure timing jitter about sub picoseconds level. The phase noise measured in Master Oscillator using PLL indicates that phase noise is low enough for PEP II to run.

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

    SciTech Connect

    Nassiri, A.; Kustom, R.L.; Kang, Y.W.

    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.

  20. Final Technical Report on STTR Project DE-FG02-02ER86145 Pressurized RF Cavities for Muon Ionization Cooling

    SciTech Connect

    Rolland Johnson

    2006-07-13

    This project was to design and build an RF test cell (TC), which could be operated at 800 MHz, filled with high pressure gases including hydrogen, at temperatures down to that of liquid nitrogen, in strong magnetic fields, in a strong radiation environment, and with interchangeable electrodes, in order to examine the use of high-pressure RF cavities for muon beam cooling.

  1. An energy recovery electron linac-on-ring collider

    SciTech Connect

    Merminga, L.; Krafft, G.A.; Lebedev, V.A.; Ben-Zvi, I.

    2000-09-14

    We present the design of high-luminosity electron-proton/ion colliders in which the electrons are produced by an Energy Recovering Linac (ERL). 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. 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. Based on extrapolations from actual measurements and calculations, energy recovery is expected to be feasible at currents of a few hundred mA and multi-GeV energies. Luminosity projections for the linac-ring scenario based on fundamental limitations are presented. 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 and a list of required R and D for the realization of such a design is presented.

  2. Beam position monitoring in the AGS Linac to Booster transfer line

    SciTech Connect

    Shea, T.J.; Brodowski, J.; Witkover, R.

    1991-12-31

    A beam position monitor system has been developed and used in the commissioning of Brookhaven`s Linac to Booster transfer line. This line transports a chopped, RF modulated H- beam from the 200 MeV Linac to the AGS Booster. Over a 15dB dynamic range in beam current, the position monitor system provides a real-time, normalized position signal with an analog bandwidth of about 20 MHz. Seven directional coupler style pickups are installed in the line with each pickup sensing both horizontal and vertical position. Analog processing electronics are located in the tunnel and incorporate the amplitude modulation to phase modulation normalization technique. To avoid interference from the 200 MHz linac RF system, processing is performed at 400 MHz. This paper will provide a system overview and report results from the commissioning experience.

  3. Beam position monitoring in the AGS Linac to Booster transfer line

    SciTech Connect

    Shea, T.J.; Brodowski, J.; Witkover, R.

    1991-01-01

    A beam position monitor system has been developed and used in the commissioning of Brookhaven's Linac to Booster transfer line. This line transports a chopped, RF modulated H- beam from the 200 MeV Linac to the AGS Booster. Over a 15dB dynamic range in beam current, the position monitor system provides a real-time, normalized position signal with an analog bandwidth of about 20 MHz. Seven directional coupler style pickups are installed in the line with each pickup sensing both horizontal and vertical position. Analog processing electronics are located in the tunnel and incorporate the amplitude modulation to phase modulation normalization technique. To avoid interference from the 200 MHz linac RF system, processing is performed at 400 MHz. This paper will provide a system overview and report results from the commissioning experience.

  4. Resonance Excitation of Longitudinal High Order Modes in Project X Linac

    SciTech Connect

    Khabiboulline, T.N.; Sukhanov, A.AUTHOR = Awida, M.; Gonin, I.; Lunin, A.AUTHOR = Solyak, N.; Yakovlev, V.; /Fermilab

    2012-05-01

    Results of simulation of power loss due to excitation of longitudinal high order modes (HOMs) in the accelerating superconducting RF system of CW linac of Project X are presented. Beam structures corresponding to the various modes of Project X operation are considered: CW regime for 3 GeV physics program; pulsed mode for neutrino experiments; and pulsed regime, when Project X linac operates as a driver for Neutrino Factory/Muon Collider. Power loss and associated heat load due to resonance excitation of longitudinal HOMs are shown to be small in all modes of operation. Conclusion is made that HOM couplers can be removed from the design of superconducting RF cavities of Project X linac.

  5. Compact LINAC for deuterons

    SciTech Connect

    Kurennoy, S S; O' Hara, J F; Rybarcyk, L J

    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.

  6. Energy Recovery Linacs

    SciTech Connect

    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.

  7. Overview of the High Intensity Neutrino Source Linac R&D program at Fermilab

    SciTech Connect

    Webber, R.C.; Appollinari, G.; Carneiro, J.P.; Gonin, I.; Hanna, B.; Hays, S.; Khabiboulline, T.; Lanfranco, G.; Madrak, R.L.; Moretti, A.; Nicol, T.; /Fermilab /Argonne

    2008-09-01

    The Fermilab High Intensity Neutrino Source (HINS) Linac R&D program is building a first-of-a-kind 60 MeV superconducting H- linac. The HINS Linac incorporates superconducting solenoids for transverse focusing, high power RF vector modulators for independent control of multiple cavities powered from a single klystron, and superconducting spoke-type accelerating cavities starting at 10 MeV. This will be the first application and demonstration of any of these technologies in a low-energy, high-intensity proton/H- linear accelerator. The HINS effort is relevant to a high intensity, superconducting H- linac that might serve the next generation of neutrino physics and muon storage ring/collider experiments. An overview of the HINS program, machine design, status, and outlook is presented.

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

    SciTech Connect

    Saini, A.; Ranjan, K.; Solyak, N.; Mishra, S.; Yakovlev, V.; /Fermilab

    2011-03-01

    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.

  9. Scanning beam switch experiment for intense rf power generation

    NASA Astrophysics Data System (ADS)

    Humphries, Stanley, Jr.; Babcock, Steven R.; Wilson, J. M.; Adler, Richard J.

    1991-04-01

    1407_57The SBS_1 experiment at Sandia National Laboratories is designed to demonstrate the feasibility of the Scanning Beam Switch for high-power rf generation. The primary application is to pulsed rf linacs and high-frequency induction accelerators. It is expected that the apparatus will generate rf output power exceeding 100 MW at 50 MHz over a 5 microsecond(s) pulse. The device can operate as an oscillator or high gain amplifier. To achieve the capability for long-macropulse and high-duty-cycle operation, SBS_1 uses a large dispenser cathode and vacuum triode input driver.

  10. Optimization of SRF Linacs

    SciTech Connect

    Powers, Tom

    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.

  11. Alternating phase focused linacs

    DOEpatents

    Swenson, Donald A.

    1980-01-01

    A heavy particle linear accelerator employing rf fields for transverse and ongitudinal focusing as well as acceleration. Drift tube length and gap positions in a standing wave drift tube loaded structure are arranged so that particles are subject to acceleration and succession of focusing and defocusing forces which contain the beam without additional magnetic or electric focusing fields.

  12. Klystron-linac combination

    DOEpatents

    Stein, W.E.

    1980-04-24

    A combination klystron-linear accelerator which utilizes anti-bunch electrons generated in the klystron section as a source of electrons to be accelerated in the accelerator section. Electron beam current is controlled by second harmonic bunching, constrictor aperture size and magnetic focusing. Rf coupling is achieved by internal and external coupling.

  13. A High-Power RF-Focusing CW Electron LINAC.

    NASA Astrophysics Data System (ADS)

    Sobenin, N. P.; Kostin, D. V.; Shvedunov, V. I.; Trower, W. P.

    1997-05-01

    Using a biperiodic accelerating structure with rectangular cavities in a high-power Continuous Wave electron LINear ACcelerator simplifies accelerator construction and reduces beam losses. By optimizing the beam aperture and coupling slots, we have obtained high focusing gradients, shunt impedances (N.P. Sobenin, V.N. Kandurin, A.I. Karev, V.N. Melekhin, V.I. Shvedunov, and W.P. Trower, in Proc. 1995 Particle Accelerator Conf., L. Gennari ed. (IEEE, Piscataway,1996) v. 3, p. 1827.), and couplings (around 20 percent). By successively rotating six rectangular accelerating cavity sections through 90^o about the beam axis and separating the sections by axially symmetric cavities which serve as drift spaces, we obtain focusing similar to that of a quadrupole magnets system. We find that a 500 mA beam accelerated from 2 to 10 MeV in a 4 m structure suffers negligible beam losses. A similar axially symmetric structure without external focusing begins losing substantial beam at around 100 mA.

  14. Development of a medium-energy superconducting heavy-ion linac.

    SciTech Connect

    Ostroumov, P. N.; Physics

    2002-03-01

    The Rare Isotope Accelerator (RIA) facility project includes a cw 1.4 GeV driver linac and a 100 MV postaccelerator both based on superconducting (SC) cavities operating at frequencies from 48 to 805 MHz. In these linacs more than 99% of the total voltage is provided by SC cavities. An initial acceleration is provided by room temperature radio frequency quadrupoles. 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. This paper presents design features of a medium-energy SC heavy-ion linac taking the RIA driver linac as an example. The dynamics of single and multiple charge-state beams are detailed, including the effects of possible errors in rf field parameters and misalignments of transverse focusing elements. The important design considerations of such linac are presented. Several new conceptual solutions in beam dynamics in SC accelerating structures for heavy-ion applications are discussed.

  15. RF transformer

    DOEpatents

    Smith, James L.; Helenberg, Harold W.; Kilsdonk, Dennis J.

    1979-01-01

    There is provided an improved RF transformer having a single-turn secondary of cylindrical shape and a coiled encapsulated primary contained within the secondary. The coil is tapered so that the narrowest separation between the primary and the secondary is at one end of the coil. The encapsulated primary is removable from the secondary so that a variety of different capacity primaries can be utilized with one secondary.

  16. Multipass Arc Lattice Design for Recirculating Linac Muon Accelerators

    SciTech Connect

    G.M. Wang, R.P. Johnson, S.A. Bogacz, D. Trbojevic

    2009-05-01

    Recirculating linear accelerators (RLA) are the most likely means to achieve rapid acceleration of short-lived muons to multi-GeV energies required for Neutrino Factories and TeV energies required for Muon Colliders. A drawback of this scheme is that a separate return arc is required for each passage of the muons through the linac. In the work described here, a novel arc optics based on a Non-Scaling Fixed Field Alternating Gradient (NSFFAG) lattice is developed, which would provide sufficient momentum acceptance to allow multiple passes (two or more consecutive energies) to be transported in one string of magnets. An RLA with significantly fewer arcs will reduce the cost. We will develop the optics and technical requirements to allow the maximum number of passes by using an adjustable path length to accurately control the returned beam to synchronize with the linac RF phase.

  17. Focusing solenoids for the HINS Linac front end

    SciTech Connect

    Terechkine, I.; Appollinari, G.; Di-Marco, J.; Huang, Y.; Orris, D.; Page, T.; Rabehl, R.; Tartaglia, M.; Tompkins, J.; /Fermilab

    2008-10-01

    The low energy part of a linac for the High Intensity Neutrino Source (HINS) project at Fermilab will use superconducting solenoids as beam focusing elements (lenses). While the lenses for the conventional DTL-type accelerating section of the front end require individual cryostats, in the superconducting accelerating sections solenoids will be installed inside RF cryomodules. Some of the lenses in the conventional and in the superconducting sections are equipped with horizontal and vertical steering dipoles. Lenses for the DTL section are in the stage of production with certification activities ongoing at Fermilab. For the superconducting sections of the linac, a prototype lens has been built and tested. Each lens will be installed in the transport channel of the accelerator so that its magnetic axis is on the beamline. Corresponding technique has been developed at Fermilab and is used during the certification process. This report summarizes design features, parameters, and test results of the focusing lenses.

  18. Multi-beam RFQ linac structure for heavy ion fusion

    NASA Astrophysics Data System (ADS)

    Hayashizaki, Noriyosu; Ishibashi, Takuya; Ito, Taku; Hattori, Toshiyuki

    2009-07-01

    Both the RF linear accelerator (linac) and the linear induction accelerator have been considered as injectors in a driver system for heavy ion fusion (HIF). In order to relax beam defocusing by space charge effect in the low-energy region, the accelerating beams that were merged and had their beam currents increased by the funnel tree system are injected into storage rings. A multi-beam linac that accelerates multiple beams in an accelerator cavity has the advantages of cost reduction and downsizing of the system. We modeled the multi-beam Interdigital-H type radio frequency quadruple (IH-RFQ) cavities with the different beam numbers and evaluated the electromagnetic characteristics by simulation. As a result, the reasonable ranges of their configuration were indicated for a practical use.

  19. Linac4 low energy beam measurements with negative hydrogen ions

    SciTech Connect

    Scrivens, R. Bellodi, G.; Crettiez, O.; Dimov, V.; Gerard, D.; Granemann Souza, E.; Guida, R.; Hansen, J.; Lallement, J.-B.; Lettry, J.; Lombardi, A.; Midttun, Ø.; Pasquino, C.; Raich, U.; Riffaud, B.; Roncarolo, F.; Valerio-Lizarraga, C. A.; Wallner, J.; Yarmohammadi Satri, M.; Zickler, T.

    2014-02-15

    Linac4, a 160 MeV normal-conducting H{sup −} linear accelerator, is the first step in the upgrade of the beam intensity available from the LHC proton injectors at CERN. The Linac4 Low Energy Beam Transport (LEBT) line from the pulsed 2 MHz RF driven ion source, to the 352 MHz RFQ (Radiofrequency Quadrupole) has been built and installed at a test stand, and has been used to transport and match to the RFQ a pulsed 14 mA H{sup −} beam at 45 keV. A temporary slit-and-grid emittance measurement system has been put in place to characterize the beam delivered to the RFQ. In this paper a description of the LEBT and its beam diagnostics is given, and the results of beam emittance measurements and beam transmission measurements through the RFQ are compared with the expectation from simulations.

  20. Design of a Marx-Topology Modulator for FNAL Linac

    SciTech Connect

    Butler, T. A.; Garcia, F. G.; Kufer, M. R.; Pfeffer, H.; Wolff, D.

    2015-04-28

    The Fermilab Proton Improvement Plan (PIP) was formed in late 2011 to address important and necessary upgrades to the Proton Source machines (Injector line, Linac and Booster). The goal is to increase the proton flux by doubling the Booster beam cycle rate while maintaining the same intensity per cycle, the same uptime, and the same residual activation in the enclosure. For the Linac, the main focus within PIP is to address reliability. One of the main tasks is to replace the present hard-tube modulator used on the 200 MHz RF system. Plans to replace this high power system with a Marx-topology modulator, capable of providing the required waveform shaping to stabilize the accelerating gradient and compensate for beam loading, will be presented, along with development data from the prototype unit.

  1. Upgrade of the Drive LINAC for the AWA Facility Dielectric Two-Beam Accelerator

    SciTech Connect

    Power, John; Conde, Manoel; Gai, Wei; Li, Zenghai; Mihalcea, Daniel; /Northern Illinois U.

    2012-07-02

    We report on the design of a seven-cell, standing-wave, 1.3-GHz rf cavity and the associated beam dynamics studies for the upgrade of the drive beamline LINAC at the Argonne Wakefield Accelerator (AWA) facility. The LINAC design is a compromise between single-bunch operation (100 nC {at} 75 MeV) and minimization of the energy droop along the bunch train during bunch-train operation. The 1.3-GHz drive bunch-train target parameters are 75 MeV, 10-20-ns macropulse duration, and 16 x 60 nC microbunches; this is equivalent to a macropulse current and beam power of 80 A and 6 GW, respectively. Each LINAC structure accelerates approximately 1000 nC in 10 ns by a voltage of 11 MV at an rf power of 10 MW. Due to the short bunch-train duration desired ({approx}10 ns) and the existing frequency (1.3 GHz), compensation of the energy droop along the bunch train is difficult to accomplish by means of the two standard techniques: time-domain or frequency-domain beam loading compensation. Therefore, to minimize the energy droop, our design is based on a large stored energy rf cavity. In this paper, we present our rf cavity optimization method, detailed rf cavity design, and beam dynamics studies of the drive beamline.

  2. Low-charge-state linac

    SciTech Connect

    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.

  3. RF thermal and new cold part design studies on TTF-III input coupler for Project-X

    SciTech Connect

    Pei, Shilun; Adolphsen, Chris E.; Li, Zenghai; Solyak, Nikolay A.; Gonin, Ivan V.

    2015-05-15

    An RF power coupler is one of the key components in a superconducting (SC) linac. It provides RF power to the SC cavity and interconnects different temperature layers (1.8 K, 4.2 K, 70 K and 300 K). The TTF-III coupler is one of the most promising candidates for the High Energy (HE) linac of Project X, but it cannot meet the average power requirements because of the relatively high temperature rise on the warm inner conductor, so some design modifications will be required. In this paper, we describe our simulation studies on the copper coating thickness on the warm inner conductor with RRR values of 10 and 100. Our purpose is to rebalance the dynamic and static loads, and finally lower the temperature rise along the warm inner conductor. Additionally, to get stronger coupling, better power handling and less multipacting probability, one new cold part design was proposed using a 60 mm coaxial line; the corresponding multipacting simulation studies have also been investigated.

  4. RF Processing of the Couplers for the SNS Superconducting Cavities

    SciTech Connect

    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.

  5. High-Power Linac for the Spallation Neutron Source

    NASA Astrophysics Data System (ADS)

    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.

  6. Design of a new VHF RF power amplifier system for LANSCE

    SciTech Connect

    Lyles, John T M

    2010-01-01

    A major upgrade is replacing much of the 40 year-old proton drift tube linac RF system with new components at the Los Alamos Neutron Science Center (LANSCE). When installed, the new system will reduce the total number of electron power tubes from twenty-four to eight in the RF powerplant. A new 200 MHz high power cavity amplifier has being developed at LANSCE. This 3.2 MW final power amplifier (FPA) uses a Thales TH628 Diacrode{reg_sign}, a state-of-the-art tetrode that eliminates the large anode modulator of the triode-based FPA that has been in use for four decades. Drive power for the FPA is provided by a new tetrode intermediate power amplifier (and a solid-state driver stage). The new system has sufficient duty-factor capability to allow LANSCE to return to 1 MW beam operation. Prototype RF power amplifiers have been designed, fabricated, and assembled, and are being tested. High voltage DC power became available through innovative re-engineering of an installed system. Details of the electrical and mechanical design of the FPA and ancillary systems are discussed.

  7. Beam loss studies in high-intensity heavy-ion linacs

    NASA Astrophysics Data System (ADS)

    Ostroumov, P. N.; Aseev, V. N.; Mustapha, B.

    2004-09-01

    The proposed Rare Isotope Accelerator (RIA) Facility, an innovative exotic-beam facility for the production of high-quality beams of short-lived isotopes, consists of a fully superconducting 1.4GV driver linac and a 140MV postaccelerator. To produce sufficient intensities of secondary beams the driver linac will provide 400kW primary beams of any ion from hydrogen to uranium. Because of the high intensity of the primary beams the beam losses must be minimized to avoid radioactivation of the accelerator equipment. To keep the power deposited by the particles lost on the accelerator structures below 1 W/m, the relative beam losses per unit length should be less than 10-5, especially along the high-energy section of the linac. A new beam dynamics simulation code TRACK has been developed and used for beam loss studies in the RIA driver linac. In the TRACK code, ions are tracked through the three-dimensional electromagnetic fields of every element of the linac starting from the electron cyclotron resonance (ECR) ion source to the production target. The simulation starts with a multicomponent dc ion beam extracted from the ECR. The space charge forces are included in the simulations. They are especially important in the front end of the driver linac. Beam losses are studied by tracking a large number of particles (up to 106) through the whole linac considering all sources of error such us element misalignments, rf field errors, and stripper thickness fluctuations. For each configuration of the linac, multiple sets of error values have been randomly generated and used in the calculations. The results are then combined to calculate important beam parameters, estimate beam losses, and characterize the corresponding linac configuration. To track a large number of particles for a comprehensive number of error sets (up to 500), the code TRACK was parallelized and run on the Jazz computer cluster at ANL.

  8. Space charge in proton linacs

    SciTech Connect

    Wangler, T. P.; Merrill, F.; Rybarcyk, L.; Ryne, R.

    1998-11-05

    Space charge effects on beam dynamics in linear accelerators are discussed. Practical linac beam dynamics calculation methods which include space charge effects are discussed. Also, the status of beam performance experiments including space charge studies are summarized.

  9. SLAC Linac Preparations for FACET

    SciTech Connect

    Erickson, R.; Bentson, L.; Kharakh, D.; Owens, A.; Schuh, P.; Seeman, J.; Sheppard, J.C.; Stanek, M.; Wittmer, W.; Yocky, G.; Wienands, U.; /SLAC

    2011-02-07

    The SLAC 3km linear electron accelerator has been cut at the two-thirds point to provide beams to two independent programs. The last third provides the electron beam for the Linac Coherent Light Source (LCLS), leaving the first two-thirds available for FACET, the new experimental facility for accelerator science and test beams. In this paper, we describe this separation and projects to prepare the linac for the FACET experimental program.

  10. A microwave power driver for linac colliders: Gigatron

    SciTech Connect

    Bizek, H.M.; Elliott, S.M.; McIntyre, P.M.; Nassiri, A.; Popovic, M.B.; Raparia, D.; Gray, H.F. . Dept. of Physics; Naval Research Lab., Washington, DC )

    1988-11-18

    The gigatron is a new rf amplifier tube designed for linac collider applications. Three design features permit extension of the lasertron concept to very high frequencies. First, a gated field-emitter array is employed for the modulated cathode. Second, a ribbon beam geometry mitigates space charge depression and facilitates efficient output coupling. Third, a traveling wave output coupler is used to obtain optimum coupling to the ribbon beam. This paper describes recent developments in the gigatron design, and progress towards experimental tests. 9 refs., 8 figs., 1 tab.

  11. Analysis of beam loss mechanism in the Project X linac

    SciTech Connect

    Carneiro, J.-P.; Lebedev, V.; Nagaitsev, S.; Ostiguy, J.-F.; Solyak, N.; /Fermilab

    2011-03-01

    Minimization of the beam losses in a multi-MW H{sup -} linac such as ProjectX to a level below 1 W/m is a challenging task. The impact of different mechanism of beam stripping, including stripping in electric and magnetic fields, residual gas, blackbody radiation and intra-beam stripping, is analyzed. Other sources of beam losses are misalignements of beamline elements and errors in RF fields and phases. We present in this paper requirements for dynamic errors and correction schemes to keep beam losses under control.

  12. Tools to Predict Beam Breakup in Recirculating Linacs

    SciTech Connect

    Kevin Beard; Nikolitsa Merminga; Byung Yunn

    2003-05-01

    An important limitation on the maximum beam current in a recirculating linac is due to beam breakup caused by higher order modes (HOM) excited in the RF cavities. A HOM delivers a transverse kick to a beam bunch, the bunch on the next pass can then drive the HOM and cause it to grow until the beam is lost. Two codes, MATBBU1 and TDBBU2, have been written to estimate the threshold current for a set of HOMs and accelerator optics. The relative merits and limitations of each is discussed in detail.

  13. SARAF Phase I linac operation in 2013-2014

    NASA Astrophysics Data System (ADS)

    Weissman, L.; Berkovits, D.; Arenshtam, A.; Ben-Aliz, Y.; Buzaglo, Y.; Dudovitch, O.; Eisen, Y.; Eliyahu, I.; Feinberg, G.; Fishman, I.; Gertz, I.; Grin, A.; Halfon, S.; Har-Even, D.; Haruvy, Y. F.; Hirschmann, D.; Hirsh, T.; Horovitz, Z.; Kaizer, B.; Kijel, D.; Kreisel, A.; Luner, Y.; Mor, I.; Paul, M.; Perry, A.; Rodnizki, J.; Shimel, G.; Shor, A.; Silverman, I.; Tessler, M.; Vaintraub, S.

    2015-10-01

    Phase I of the SARAF superconducting RF linac is under operation at the Soreq Nuclear Research Center. The present status of Phase I main components is reported, as well as, the beam operation experience accumulated in 2013-2014. The latter include acceleration of a 2 mA and 1.6 mA CW proton beams at energies of 2 MeV and 3.9 MeV correspondingly and 1 mA pulsed, duty cycle of few %, deuteron beams up to 5.6 MeV. The recent experiments include operation of intense CW proton beams on the liquid lithium target.

  14. HINS Linac front end focusing system R&D

    SciTech Connect

    Apollinari, G.; Carcagno, R.H.; Dimarco, J.; Huang, Y.; Kashikhin, V.V.; Orris, D.F.; Page, T.M.; Rabehl, R.; Sylvester, C.; Tartaglia, M.A.; Terechkine, I.; /Fermilab /Argonne

    2008-08-01

    This report summarizes current status of an R&D program to develop a focusing system for the front end of a superconducting RF linac. Superconducting solenoids will be used as focusing lenses in the low energy accelerating sections of the front end. The development of focusing lenses for the first accelerating section is in the production stage, and lens certification activities are in preparation at FNAL. The report contains information about the focusing lens design and performance, including solenoid, dipole corrector, and power leads, and about cryogenic system design and performance. It also describes the lens magnetic axis position measurement technique and discusses scope of an acceptance/certification process.

  15. AMPERE AVERAGE CURRENT PHOTOINJECTOR AND ENERGY RECOVERY LINAC.

    SciTech Connect

    BEN-ZVI,I.; BURRILL,A.; CALAGA,R.; ET AL.

    2004-08-17

    High-power Free-Electron Lasers were made possible by advances in superconducting linac operated in an energy-recovery mode. 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. We 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, an accelerator cavity, both capable of producing of the order of one ampere average current and plans for an ERL based on these units.

  16. RF System Requirements for a Medium-Energy Electron-Ion Collider (MEIC) at JLab

    SciTech Connect

    Rimmer, Robert A; Hannon, Fay E; Guo, Jiquan; Huang, Shichun; Huang, Yulu; Wang, Haipeng; Wang, S

    2015-09-01

    JLab is studying options for a medium energy electron-ion collider that could fit on the JLab site and use CEBAF as a full-energy electron injector. A new ion source, linac and booster would be required, together with collider storage rings for the ions and electrons. In order to achieve the maximum luminosity these will be high-current storage rings with many bunches. We present the high-level RF system requirements for the storage rings, ion booster ring and high-energy ion beam cooling system, and describe the technology options under consideration to meet them. We also present options for staging that might reduce the initial capital cost while providing a smooth upgrade path to a higher final energy. The technologies under consideration may also be useful for other proposed storage ring colliders or ultimate light sources.

  17. Beam position correction in the Fermilab Linac

    NASA Astrophysics Data System (ADS)

    Junck, K. L.; McCrory, E.

    1994-08-01

    Orbit correction has long been an essential feature of circular accelerators, storage rings, multipass linacs, and linear colliders. In a drift tube linear accelerator (DTL) such as the H- Linac at Fermilab, beam position monitors (BPMs) and dipole corrector magnets can only be located in between accelerating tanks. Within a tank many drift tubes (from 20 to 60) each house a quadrupole magnet to provide strong transverse focusing of the beam. With good alignment of the drift tubes and quadrupoles and a sufficiently large diameter for the drift tubes, beam position is not typically a major concern. In the Fermilab DTL, 95 percent of the beam occupies only 35 percent of the available physical aperture (4.4 cm). The recent upgrade of the Fermilab Linac from a final energy of 200 MeV to 400 MeV has been achieved by replacing four 201.25 MHz drift tube linac tanks with seven 805 MHz side-coupled cavity modules (the high energy portion of the linac or HEL). In order to achieve this increase in energy within the existing enclosure, an accelerating gradient is required that is a factor of 3 larger than that found in the DTL. This in turn required that the physical aperture through which the beam must pass be significantly reduced. In addition, the lattice of the side-coupled structure provides significantly less transverse focusing than the DTL. Therefore in the early portion of the HEL the beam occupies over 95 percent of the available physical aperture (3.0 cm). In order to prevent beam loss and the creation of excess radiation, the ability to correct beam position throughout the HEL is of importance. An orbit smoothing algorithm commonly used in the correction of closed orbits of circular machines has been implemented to achieve a global least-squares minimization of beam position errors. In order to accommodate several features of this accelerator a refinement in the algorithm has been made to increase its robustness and utilize correctors of varying strengths.

  18. Beam position correction in the Fermilab linac

    SciTech Connect

    Junck, K.L.; McCrory, E.

    1994-08-01

    Orbit correction has long been an essential feature of circular accelerators, storage rings, multipass linacs, and linear colliders. In a drift tube linear accelerator (DTL) such as the H- Linac at Fermilab, beam position monitors (BPMs) and dipole corrector magnets can only be located in between accelerating tanks. Within a tank many drift tubes (from 20 to 60) each house a quadrupole magnet to provide strong transverse focusing of the beam. With good alignment of the drift tubes and quadrupoles and a sufficiently large diameter for the drift tubes, beam position is not typically a major concern. In the Fermilab DTL, 95% of the beam occupies only 35% of the available physical aperture (4.4 cm). The recent upgrade of the Fermilab Linac from a final energy of 200 MeV to 400 MeV has been achieved by replacing four 201.25 MHz drift tube linac tanks with seven 805 MHz side-coupled cavity modules (the high energy portion of the linac or HEL). In order to achieve this increase in energy within the existing enclosure, an accelerating gradient is required that is a factor of 3 larger than that found in the DTL. This in turn required that the physical aperture through which the beam must pass be significantly reduced. In addition, the lattice of the side-coupled structure provides significantly less transverse focusing than the DTL. Therefore in the early portion of the HEL the beam occupies over 95% of the available physical aperture (3.0 cm). In order to prevent beam loss and the creation of excess radiation, the ability to correct beam position throughout the HEL is of importance. An orbit smoothing algorithm commonly used in the correction of closed orbits of circular machines has been implemented to achieve a global least-squares minimization of beam position errors. In order to accommodate several features of this accelerator a refinement in the algorithm has been made to increase its robustness and utilize correctors of varying strengths.

  19. Rf power sources for 1990 and beyond

    SciTech Connect

    Reid, D.W.

    1986-01-01

    This paper will discuss the types of devices and system architectures that show promise in providing rf power sources for future space requirements. It will extrapolate these solutions to accelerators that are now being planned for construction and commissioning in the 1990s and will suggest technological advantages of using SDI-developed rf systems. Finally, the present state of the various SDI-sponsored high-powered rf-development programs will be reviewed.

  20. Induction Linac Pulsers

    SciTech Connect

    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 reflected back into the

  1. PHOTOINJECTED ENERGY RECOVERY LINAC UPGRADE FOR THE NATIONAL SYNCHROTRON LIGHT SOURCE.

    SciTech Connect

    BEN-ZVI,I.; BABZIEN,M.; BLUM,E.; CASEY,W.; CHANG,X.; GRAVES,W.; HASTINGS,J.; HULBERT,S.; JOHNSON,E.; KAO,C.C.; KRAMER,S.; KRINSKY,S.; MORTAZAVI,P.; MURPHY,J.; OZAKI,S.; PJEROV,S.; PODOBEDOV,B.; RAKOWSKY,G.; ROSE,J.; SHAFTAN,T.; SHEEHY,B.; SIDDONS,D.; SMEDLEY,J.; SRINIVASAN-RAO,T.; TOWNE,N.; WANG,J.M.; WANG,X.; WU,J.; YAKIMENKO,V.; YU,L.H.

    2001-06-18

    We describe a major paradigm shift in the approach to the production of synchrotron radiation This change will considerably improve the scientific capabilities of synchrotron light sources. We introduce plans for an upgrade of the National Synchrotron Light Source (NSLS). This upgrade will be based on the Photoinjected Energy Recovering Linac (PERL). This machine emerges from the union of two technologies, the laser-photocathode RF gun (photoinjector) and superconducting linear accelerators with beam energy recovery (Energy Recovering Linac). The upgrade will bring the NSLS users many new insertion device beam lines, brightness greater than 3rd generation lightsource's and ultra-short pulse capabilities, not possible with storage ring light sources.

  2. Rheumatoid factor (RF)

    MedlinePlus

    Rheumatoid factor (RF) is a blood test that measures the amount of the RF antibody in the blood. ... these conditions still have a "normal" or low RF. Normal value ranges may vary slightly among different ...

  3. An Energy Recovery Electron Linac On Ring Collider

    SciTech Connect

    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.

  4. Permanent-magnet quadrupoles in an RFQ linacs

    SciTech Connect

    Lysenko, W.P.; Wang, T.F.

    1985-01-01

    We investigated the possibility of increasing the current-carrying capability of radio-frequency quadrupole (RFQ) linear accelerators by adding permanent-magnet quadrupole (PMQ) focusing to the existing transverse focusing provided by the rf electric field. Increased transverse focusing would also allow shortening RFQ linacs by permitting a larger accelerating gradient, which is normally accomplished by an undesirable increased transverse rf defocusing effect. We found that PMQs were not helpful in increasing the transverse focusing strength in an RFQ. This conclusion was reached after some particle tracing simulations and some analytical calculations. In our parameter regime, the addition of the magnets increases the betatron frequency but does not result in improved focusing because the increased flutter more than offsets the gain from the increased betatron frequency.

  5. Simulation studies of the LAMPF proton linac

    SciTech Connect

    Garnett, R.W.; Gray, E.R.; Rybarcyk, L.J.; Wangler, T.P.

    1995-05-01

    The LAMPF accelerator consists of two 0.75-MeV injectors, one for H{sup +} and the other for H{sup {minus}}, a separate low-energy beam transport (LEBT) line for each beam species, a 0.75 to 100-MeV drift-tube linac (DTL) operating at 201.25-MHz, a 100-MeV transition region (TR), and a 100 to 800-MeV side-coupled linac (SCL) operating at 805-MHz. Each LEBT line consists of a series of quadrupoles to transport and transversely match the beam. The LEBT also contains a prebuncher, a main buncher, and an electrostatic deflector. The deflector is used to limit the fraction of a macropulse which is seen by the beam diagnostics throughout the linac. The DTL consists of four rf tanks and uses singlet FODO transverse focusing. The focusing period is doubled in the last two tanks by placing a quadrupole only in every other drift-tube. Doublet FDO transverse focusing is used in the SCL. The TR consists of separate transport lines for the H{sup +} and H{sup {minus}} beams. The pathlengths for the two beams differ, by introducing bends, so as to delay arrival of one beam relative to the other and thereby produce the desired macropulse time structure. Peak beam currents typically range from 12 to 18-mA for varying macropulse lengths which give an average beam current of 1-mA. The number of particles per bunch is of the order 10{sup 8}. The work presented here is an extension of previous work. The authors have attempted to do a more complete simulation by including modeling of the LEBT. No measurements of the longitudinal structure of the beam, except phase-scans, are performed at LAMPF. The authors show that, based on simulation results, the primary causes of beam spill are inefficient longitudinal capture and the lack of longitudinal matching. Measurements to support these claims are not presently made at LAMPF. However, agreement between measurement and simulation for the transverse beam properties and transmissions serve to benchmark the simulations.

  6. Diagnostic and numerical studies of the IPNS LINAC with a recently installed buncher amplifier.

    SciTech Connect

    Dooling, J. C.; Donley, L. I.; McMichael, G. E.; Stipp, V. F.

    2002-09-17

    The Intense Pulse Neutron Source (IPNS) 50-MeV Drift-Tube Linac uses a single-gap, single-harmonic buncher cavity to increase transmission efficiency. However, it is also the case that the linac output beam longitudinal and transverse emittance is dependent on buncher amplitude and phase as well as with the input beam energy and emittance. The linac is the injector for a Rapid Cycling Synchrotron (RCS) that increases the beam energy to 450 MeV and shortens the pulse to the 100 ns region. The RCS is operated loss-limited, and its operating current is strongly dependent on the properties (emittance, and its variation during the pulse) of the beam from the linac. A new amplifier has been installed allowing for better amplitude and phase control of buncher rf. This new amplifier gives independent control of amplitude and phase, permitting more systematic studies of the relation between linac and RCS performance. This paper presents the results of recent studies where we characterize beam properties that lead to high efficiency operation in both linac and RCS, and compare them with simulation calculations.

  7. RF Conditioning and testing of fundamental power couplers for the RIA project

    SciTech Connect

    M. Stirbet; J. Popielarski; T. L. Grimm; M. Johnson

    2003-09-01

    The Rare Isotope Accelerator (RIA) is the highest priority of the nuclear physics community in the United States for a major new accelerator facility. A principal element of RIA will be a superconducting 1.4 GeV superconducting ion linac accelerating ions of isotopes from hydrogen to uranium onto production targets or for further acceleration by a second superconducting linac. The superconducting linac technology is closely related to that used at existing accelerators and the Spallation Neutron Source. Taking advantage of JLAB's SRF Institute facilities and expertise for the SNS project, preparation of couplers, RF conditioning and high power tests have been performed on fundamental power couplers for RIA project.

  8. Proton Linac Front End for High Intensity Neutrino Source at Fermilab

    NASA Astrophysics Data System (ADS)

    Tam, Wai-Ming; Apollinari, Giorgio; Madrak, Robyn; Moretti, Alfred; Ristori, Leonardo; Romanov, Gennady; Steimel, James; Webber, Robert; Wildman, David

    2008-04-01

    Fermilab has recently proposed the construction of an 8 GeV superconducting linac for the exploration of the high intensity frontier. The High Intensity Neutrino Source (HINS) R&D program was established to explore the feasibility of certain technical solutions proposed for the front end of a high intensity linac. The low energy (˜60 MeV) section operates at 325 MHz and comprises an RFQ, two re-buncher cavities, 16 room temperature (RT) and 29 superconducting cross-bar H-type resonators, and superconducting solenoid focusing elements. One of the distinguishing features of this linac is the use of one klystron to feed multiple radio frequency (RF) elements. As an example, the RFQ, the re-bunchers and the 16 RT cavities are powered by a single 2.5 MW pulsed klystron. To achieve individual control over the phase and the voltage amplitude, each of the RF elements is equipped with a high power vector modulator. The RF control system will be discussed. The first RT cavity is completed with a power coupler, two mechanical tuners, vacuum and cooling systems, and has been RF conditioned. Preliminary tests on resonance frequency stability control and tests results of the cavity resonance frequency response to cooling water temperature and tuner position will also be discussed.

  9. Final Report for "Tech-X Corporation work for the SciDAC Center for Simulation of RF Wave Interactions with Magnetohydrodynamics (SWIM)"

    SciTech Connect

    Jenkins, Thomas G.; Kruger, Scott E.

    2013-03-25

    Work carried out by Tech-X Corporation for the DoE SciDAC Center for Simulation of RF Wave Interactions with Magnetohydrodynamics (SWIM; U.S. DoE Office of Science Award Number DE-FC02-06ER54899) is summarized and is shown to fulfil the project objectives. The Tech-X portion of the SWIM work focused on the development of analytic and computational approaches to study neoclassical tearing modes and their interaction with injected electron cyclotron current drive. Using formalism developed by Hegna, Callen, and Ramos [Phys. Plasmas 16, 112501 (2009); Phys. Plasmas 17, 082502 (2010); Phys. Plasmas 18, 102506 (2011)], analytic approximations for the RF interaction were derived and the numerical methods needed to implement these interactions in the NIMROD extended MHD code were developed. Using the SWIM IPS framework, NIMROD has successfully coupled to GENRAY, an RF ray tracing code; additionally, a numerical control system to trigger the RF injection, adjustment, and shutdown in response to tearing mode activity has been developed. We discuss these accomplishments, as well as prospects for ongoing future research that this work has enabled (which continue in a limited fashion under the SciDAC Center for Extended Magnetohydrodynamic Modeling (CEMM) project and under a baseline theory grant). Associated conference presentations, published articles, and publications in progress are also listed.

  10. CLIC RF High Power Production Testing Program

    SciTech Connect

    Syratchev, I.; Riddone, G.; Tantawi, S.G.; /SLAC

    2011-11-02

    The CLIC Power Extraction and Transfer Structure (PETS) is a passive microwave device in which bunches of the drive beam interact with the impedance of the periodically loaded waveguide and generate RF power for the main linac accelerating structure. The demands on the high power production ({approx} 150 MW) and the needs to transport the 100 A drive beam for about 1 km without losses, makes the PETS design rather unique and the operation very challenging. In the coming year, an intense PETS testing program will be implemented. The target is to demonstrate the full performance of the PETS operation. The testing program overview and test results available to date are presented.