| Paper | Title | Page |
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| THPLS099 | Fast Kicker Systems for the SOLEIL Booster Injection and Extraction, with Full Solid-state Pulsed Power Supplies | 3505 |
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| The Booster of SOLEIL needs injection and extraction kicker systems with fast transition times, good flat top and low jitter, to allow a satisfactory injection efficiency of the Storage Ring injection. So all the kicker systems have been optimised, to fulfil specifications and to permit the use of solid state switching electronics. This contribution presents the ceramic vacuum chambers and magnets design, the specific pulse forming scheme and the realisation of the pulsed power supplies working up to 20 kV. Electrical and magnetic measurements results of kickers systems are given, and also its operation status from the first SOLEIL Booster injection in July 2005. | ||
| THPLS100 | Four Matched Kicker Systems for the SOLEIL Storage Ring Injection, a Full Solid State Solution of Pulsed Power Supplies Working at High Current | 3508 |
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| The Top Up injection mode of the SOLEIL Storage Ring needs a very good matching of the four kicker magnet fields. But their implantation inside the straight section dedicated to SR injection imposed high level forces on each of the four kickers. This contribution describes the ceramic vacuum chambers and magnets design optimised to provide a very good identity of the four magnets. The pulsed power supplies, based on IGBT high voltage modules, designed to work at high current (5250 A-9000 V) could be located outside the SR tunnel. We highlight the specific development on all components specification and electrical scheme that permits to reach such a challenge. The electrical and magnetic measurement results are reported. | ||
| THPLS101 | Eddy Current Septum Magnets for Booster Injection and Extraction and Storage Ring Injection at Synchrotron SOLEIL | 3511 |
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| Eddy current thin septum magnets are used to inject or extract the electron beam to/from the Booster and to the Storage Ring of SOLEIL. Good transverse homogeneity in the gap for injected beam, and low leakage field on circulating beam is needed, as well as pulse stability. The Top Up injection mode of the Storage Ring needs a very low level of leakage field on the stored beam path. Operating currents are from 2000 A and 3000 A for Booster injection and extraction, to 5100 A for SR injection. This contribution will describe the magnets and the pulsed power supplies design. The electrical and magnetic measurement results will be presented, with a specific emphasis on the improvements needed to reduce the level of leakage field of the SR septum magnet. | ||
| THPLS102 | Optimisation of the Coating Thickness on the Ceramic Chambers of the SOLEIL Storage Ring | 3514 |
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| The SOLEIL storage ring injection section integrates four matched injection kicker magnets, two diagnostics kicker magnets and a beam shaker, which need ceramic vacuum chambers with an inner titanium coating. For each utilisation (according with its field amplitude and its time or frequency domain), the coating thickness has been evaluated from the different points of view: field attenuation, beam deposited power, magnet excitation deposited power, and cooling efficiency. So we could determine the different coating thicknesses and tolerances needed according to the different magnetic field shapes. The realised ceramic chambers have adequate coating resistances, with in particular a low non-uniformity among the matched injection kicker magnets chambers. | ||
| THPLS103 | Investigations of the Longitudinal Phase Space at PITZ | 3517 |
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The correlation between the positions of the particles in the bunch and their longitudinal momenta has to be analysed in order to optimize photo injectors for Free-Electron Lasers (FELs). Longitudinal phase space measurements at the upgraded PITZ facility* will be presented in this paper. Measurements of the complete longitudinal phase space and its projections behind the gun are compared with simulations. Momentum measurements after a booster cavity will be discussed.
*A.Oppelt et al. "Status and first results from the upgraded PITZ facility", FEL Conf. 2005. |
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| THPLS104 | Optimization Studies of the FERMI@ELETTRA Photoinjector | 3520 |
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| In the framework of the FERMI@ELETTRA project the electron beam characteristics strongly depend from the two operating modes: FEL1 (100nm-40nm) with a photon pulse around 100fs and FEL2 (40nm-10nm) with a long photon pulse (~1ps) having a high resolution spectral bandwidth. We present the multi-particles tracking code results concerning the photoinjector, which includes the RF gun and the first two accelerating sections, describing two possible electron bunch lengths, satisfying the two FEL operation modes. The injector optimization relative to the two options, aimed to produce a very low projected emittance (around 1 mm mrad) with a uniform behavior of the slice parameters (emittance and energy spread) along the bunch, is described in this paper. Moreover sensitivity studies, time and energy jitters estimations are presented for both cases. | ||
| THPLS105 | Characterization of the SPARC Photo-injector with the Movable Emittance Meter | 3523 |
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| As a first stage of the commissioning of SPARC accelerator a complete characterization of the photo-injector is planned. The objective is the optimization of the RF-gun setting that best matches the design working point and, generally, a detailed study of the emittance compensation process providing the optimal value of emittance at the end of the linac. For this purpose a novel beam diagnostic, the emittance-meter, consisting of a movable emittance measurement system, was conceived and built. This paper presents the results of the first measurements with the emittance-meter showing the characteristics and the performance at the SPARC photo-injector. | ||
| THPLS107 | Possibility of the Beam Injection Using a Single Pulsed Sextupole Magnet in Electron Storage Rings | 3526 |
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| Recently, we succeeded in the beam injection using a single pulsed quadrupole magnet (PQM) at the Photon Factory Advanced Ring (PF-AR). The PQM enables us to inject the beam into the storage ring without the local bump by several pulsed dipole magnets. In addition, since the stored beam is not kicked when the beam passes through the magnetic center of the PQM, we can avoid the coherent beam oscillation, which is often produced by the unclosed local bump. It is important for the top-up injection in electron storage rings as synchrotron radiation sources. However, in the case of the PQM, we have the problem that the beam profile slightly changes turn-by-turn after the excitation of the PQM. In order to solve it, we investigated the possibility of the beam injection using a single pulsed sextupole magnet (PSM) instead of the PQM. Here, we will present the simulation of the beam injection using the PSM. | ||
| THPLS108 | Performance Test of RF Photo-Cathode Gun at the PAL | 3529 |
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| A RF photo-cathode (RF PC) gun with 1.6 cell cavity is installed for the fs-FIR (Femto-second Far Infrared Radiation) facility being built at the Pohang Accelerator Laboratory (PAL). A short, intense, and low emittance electron beams are produced by the RF PC gun. Performance test of the gun is done include the measurement of RF chraterizations such as a resonant frequency, a mode separation, and etcs. The diagnostics of the beam according to the beam parameters such as phase, charge, and energy, and emittance are done. In this article, we present the measurement results of the RF charaterizations and the beam parameter diagnostics of the RF PC gun at the PAL. | ||
| THPLS109 | Measurements and Diagnostics on the MAX Recirculator | 3532 |
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| The MAX Recirculator is a unique accelerator, a two-pass linac at 500 MeV, that operates as injector for three storage rings. Here are presented some discussions on measurments of beam parameters such as emittance, energy spread, and bunch length. We describe what measurements are done, by wich methods, results, and how they can be improved. Also, we make an analysis of What methods and hardware are needed to perform the measurements that can't be done with the equipment in place today. | ||
| THPLS110 | Injection Scheme for TPS Storage Ring | 3535 |
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| Taiwan Photon Source(TPS), a 3~3.3 GeV synchrotron light source with full energy injection is proposed to be built at NSRRC in Taiwan. In this paper we report the design of injection scheme for TPS. The space allocation of the injection components, the bumper design, the aperture consideration and the injection dynamics of injected and stored beam will all be discussed. The particle tracking of first few turns of injection is performed to evaluate the injection efficiency with the errors caused by the time jitter and amplitude stability of injection kickers. The issue of constant current operation will be also addressed. | ||
| THPLS111 | Beam Loading Measurement and its Application to the Harmonic RF Control of the APS PAR | 3538 |
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| The particle accumulator ring (PAR) has dual rf systems: a CW mode fundamental rf system (RF1) operating at 9.77 MHz that accumulates multiple linac pulses into a 0.8-ns bunch, and a 12th harmonic rf (RF12) that compresses the bunch length further to 0.34 ns for injection into the booster. The RF12 capture process is critical for optimal performance of the PAR. We investigated the effects of beam loading during the RF12 capture and bunch length compression process with both spectrum analysis and streak camera imaging. Based on these observations, a new timing scheme for the RF12 tuner and power control was implemented, which has substantially improved the performance of the PAR. We report our observation, the new timing scheme, and beam parameters after optimization. | ||
| THPLS112 | Electron Multipacting Observation and Simulation in the APS PAR | 3541 |
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| The particle accumulator ring (PAR) has both fundamental and 12th harmonic rf systems. Gap voltage fluctuations were experienced after vacuum work was performed on the PAR during a maintenance period. This has caused intermittent beam instability and prevented us from running the PAR fundamental rf system at normal power level. Our investigation has concluded that the problem was caused by electron multipacting in the center vacuum chamber of the cavity. We were able to suppress the multipacting by applying a solenoid field in the suspected region. Computer simulation is underway in order to find the location and the parameter range of the multipacting. In this paper we report the experimental observations and results of the simulation relevant to the phenomena. | ||
| THPLS113 | Design of a Fast Extraction Kicker for the Accelerator Test Facility | 3544 |
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We present a study for the design of a fast extraction kicker to be installed in the Advanced Test Facility ring. The purpose of the project is to test the technologies to be used in the design of the extraction kickers for the ILC damping rings. The kicker's rise and fall times are important parameters in the design of the damping rings, as they limit the minimum distance between bunches and ultimately define a lower boundary for the ring length. We propose a stripline kicker composed of several 20-cm long sections, grouped in two locations in the ATF damping ring. An analytical study of the kicker's parameters and computer simulations using Microwave Studio* point out the strict requirements on the pulsers, in order to be able to satisfy the design parameters.
*http://www.cst.com |
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| THPLS114 | "CAMSHAFT" Bunch Kicker Design for the ALS Storage Ring | 3547 |
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| ALS is a 1.9 GeV third generation synchrotron light source that has been operating since 1992 at Lawrence Berkeley National Laboratory. There are two typical modes of operation of the ALS storage ring. In multibunch mode, the ring is filled to a current of 400 mA in 276 consecutive bunches with a single "camshaft" bunch located in the middle of the 52 bucket gap (h=328). Twice each year, ALS operates in "two-bunch" mode for periods of two weeks delivering 20 mA of average beam current in two diametrically opposite bunches to a small group of users requiring light pulses at lower rates. We plan to build a fast kicker system that will supply single bunch light to users during multibunch operation by displacing the orbit of the camshaft bunch at a prescribed frequency (every N turns). Realization of this project will increase ALS beam availability to multibunch users by at least 10%. This paper will describe the hardware design (pulse generator and beam deflection device) and the test results of the prototype kicker unit. | ||
| THPLS115 | Simulation and Optimisation of a 100 mA DC Photo-Injector | 3550 |
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| A prototype 100mA injector is presently being designed and manufactured jointly between Thomas Jefferson National Accelerator Facility (J-Lab) and Advanced Energy Systems (AES). This paper discusses the physics optimisation and performance of the injector, which has been studied using the space-charge tracking code ASTRA. The objective is to operate the 7MeV injector with 135pC electron bunches at 748.5MHz repetition rate. We show that the longitudinal and transverse electron bunch properties can be realised within the constraints of the design. |