| Paper | Title | Page |
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| WEPC005 | Design Considerations of the TPS Linac-to-booster Transfer Line | 1989 |
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| Design considerations of the linac to booster (LTB) transfer line for Taiwan Photon Source (TPS) project is described in this report. Electron beam from the linac with 150 MeV, 50 π-mm-mrad normalized emittance and 0.5% energy spread will be transferred to a booster synchrotron of 489.6 m. This LTB transfer line is designed with the flexible tuning capability and the diagnostics are included. Matching of transverse beam parameters from linac to booster is deliberated. The on-axis injection scheme with repetition rate around 2 or 3 Hz and efficiency with beta-mismatch for top-up operation is also studied. | ||
| WEPC041 | The Injection System of the SSRF Storage Ring | 2076 |
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| A multi-turn injection scheme with four kickers and two septa is used for injection into SSRF storage ring. The 3.5GeV electron beam from the SSRF booster is injected with 6.3 degrees horizontally. All injection elements are set in one 12m long straight section for the requirement of the top-up operation. Simulation and commissioning results will be presented in this paper, such as the injection efficiency and the disturbance on stored beam. | ||
| WEPC066 | The Transport Line Upgrade Proposal of Hefei Light Source | 2145 |
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| The injector of Hefei Light Source is a 200 MeV linac. A 55m transport line transfer beam to injection point of storage ring. At current stage, the mismatch of phase space is a potential source limiting the injection efficiency and stable operation of light source. A new focusing configuration of transport line was put forward, where the Twiss parameters matching was implemented. A skew quadrupole was introduced to make horizontal dispersion function matching. This matching between transport line and storage ring would be helpful to improve injection efficiency of HLS storage ring. | ||
| WEPC067 | Optics for the ALBA Booster Synchrotron | 2148 |
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| The ALBA booster is a full energy injector of 3 GeV for top-up operation that will be installed in the same tunnel as the Storage Ring. Its large circumference of 249.6 m and the magnetic lattice with combined function bending magnets provide an equilibrium emittance as low as 9 nm rad. In this paper the linear optics functions, the aperture requirements and the gradient error tolerances in the dipoles and quadrupoles are discussed. The closed orbit correction scheme consists of 44 horizontal and 28 vertical correctors and 44 BPMs. A solution that requires a reduced number of BPMs has been studied as well. Chromaticity correction and dynamic aperture during the ramping have been also investigated. Finally, the injection and extraction schemes are described. | ||
| WEPC068 | Injection into the ALBA Storage Ring | 2151 |
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| Injection into the ALBA Storage Ring is performed at an energy of 3 GeV in a 7 m long straight section. The injection bump is performed with four kickers. Pulsed magnets are described, in particular the active septum magnet. Tracking of particles has been simulated over a large number of turns, taking into account the magnet errors, the sextupole fields and the physical apertures all along the machine. Specific requirements for top-up injection have been examined, such as a perfect closure of the injection bump, the residual vertical field and the leakage fields from the septum. | ||
| WEPC069 | A Possible THz Radiation Source with a Train of Short Pulses in the SPARC High Brightness Photoinjector | 2154 |
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| A radiofrequency electron gun followed by a compressor can generate trains of THz sub-picosecond electron pulses by illuminating the photocathode with a comb laser pulse. This structure of the beam can be used to produce coherent radiation. A feasibility study for a possible experiment at SPARC to be realized with the addition of a dedicated magnetic chicane is discussed. An optimization study of a magnetic chicane with a negative and variable R56 is studied, together with a set of parameters relative to the SPARC machine with the intent of demonstrating the feasibility of this experiment. The dynamics is studied within the SPARC system with the PARMELA code and with the RETAR code for the evaluation of the radiation. | ||
| WEPC070 | Further Optimisation of the Diamond Light Source Injector | 2157 |
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| The Diamond Light Source injector consists of a 100MeV linac and a 3GeV full-energy booster, and has been providing beam to the storage ring since September 2006. System optimisation has continued throughout the first year of user operation at Diamond. Beam losses on injection into both the booster and storage ring have been minimised by optimisation of operating parameters and the stabilisation of injection elements, particularly the elimination of a linac energy beat. High level software has been developed to monitor turn-by-turn BPM data, allowing booster chromaticity to be measured. The same software generates an automatic log of storage ring frequency spectra on injection, enabling the parasitic measurement of storage ring tune, and can be used to provide information on storage ring impedance and chromaticity. Further optimisation of single bunch injection has been carried out in preparation for top-up operation, and top-up capability has been extended to provide a single bunch filling mode for the storage ring. Injection into the booster at low energy has been demonstrated, providing a mode of operation for the injection system in the event of a linac klystron failure. | ||
| WEPC071 | Installation and Commissioning of the 100 MeV Preinjector Linac of the New Elettra Injector | 2160 |
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| A new full energy injector has been installed and commissioned at Sincrotrone Trieste, the Italian Synchrotron Light Source Facility in Trieste. It consists of a 100 MeV Preinjector Linac (PL) followed by a 2.5 GeV Booster Synchrotron (BS), that will fill the Elettra Storage Ring (SR) with 2.0 GeV and 2.4 GeV electrons. Here a complete description of the preinjector linac and its characterization in terms of beam parameters will be presented and discussed. | ||
| WEPC073 | Layout of the Beam Switchyard at the European XFEL | 2163 |
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| A unique feature of the European XFEL will be the possibility to distribute electron bunches of one beam pulse to different FEL beam lines. This is achieved by using a combination of fast kickers and a DC septum. Integration of a beam abortion dump allows a flexible selection of the bunch pattern at the FEL experiment, while the superconducting linear accelerator operates with constant beam-loading. We describe the principal scheme, the geometrical and optical layout and deal with stability and technical issues like the fast kicker development. | ||
| WEPC074 | The Injection and Extraction Kicker Magnets of the Elettra Booster | 2166 |
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| The design, realization and performance of the injection and extraction Kicker magnets of the Booster of Elettra are presented. A window-frame geometry has been chosen due to its transverse symmetry in order to obtain a good field symmetry. A suitable layout for in vacuum operation has been developed. The magnetic core is made by CMD 5005 ferrite blocks, assembled in a stainless steel case, obtaining a single module; one module has been used for the injection Kicker and two such modules, connected in parallel, have been used for the extraction Kicker. In both cases the magnet modules have been installed in stainless steel vacuum chambers. The design of the magnetic core has been checked using the well known 2D POISSON code, thanks to the fact that the magnet’s gap is narrow compared to its length. | ||
| WEPC075 | Recent Results and Future Perspectives of the SPARC Project | 2169 |
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| The SPARC project foresees the realization of a high brightness photo-injector to produce a 150-200 MeV electron beam to drive 500 nm FEL experiments in various configurations, a Thomson backscattering source and a plasma accelerator experiment. The SPARC photoinjector is also the test facility for the recently approved VUV FEL project named SPARX. As a first stage of the commissioning a complete characterization of the photoinjector has been accomplished with a detailed study of the emittance compensation process downstream the gun-solenoid system and the demonstration of the emittance oscillation in the drift. The second stage of the commissioning, that is currently underway, foresees a detailed analysis of the beam matching with the linac in order to confirm the theoretically prediction of emittance compensation based on the “invariant envelope” matching and the demonstration of the “velocity bunching” technique in the linac. In this paper we report the experimental results obtained so far and the scientific program for the near future. | ||
| WEPC076 | Remote Tilt-control System of Injection Bump Magnet in the SPring-8 Storage Ring | 2172 |
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| The SPring-8 storage ring has four pulse-bump magnets to generate bump orbit for beam injection. Rotational error of the bump magnets around a beam-axis (tilt) induces the stored-beam oscillation in vertical direction due to horizontal error field. In the top-up operation, vertical perturbation of the stored-beam during beam injection is mainly produced by the tilt. We evaluated the tilt angle by measuring of the perturbation turn-by-turn using a single-pass BPM system and realigned bump magnets manually inside the accelerator tunnel. It was required to repeat the measurement and realignment processes two or three times for convergence. To correct the tilts smoothly, we developed a remote tilt-control system. The system consists of two fixed and one movable supports in vertical direction under each bump magnets. The movable support is driven by a stepper motor through 1/30 worm gear in the range of ±4 mrad with the accuracy of less than 0.1 mrad. By using this system, we succeeded complete on-beam reduction of the perturbation. | ||
| WEPC077 | Pulsed Magnet Systems for the SSRF Injection and Extraction | 2175 |
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| The injector and the storage ring of the Shanghai Synchrotron Radiation Facility (SSRF) have been built and the commissioning procedure and results are satisfactory. Total of fourteen pulsed magnets are used for the SSRF injection and extraction. In-vacuum ferrite kicker magnets, eddy current septa and 200ms bump magnets are offered for booster injection and extraction. A symmetric bump of stored beam is performed in one of the long straight section of the SSRF storage ring. Four identical kickers with ceramic vacuum chamber and two septa with a sheet of magnetic screening material around the stored beam are equipped for the storage ring injection. The septa can reach maximum 900 Tm field at 8600A with less than 0.01% leakage field for stored beam. And the identical 3.8 us half-sine pulse waveform is excited on the kicker magnets with 3.6kA current and exacted timing. The stability of ±0.05% (rms), low leakage field and identical bump are emphasized so that the residual closed orbit disturbance can be minimized for top-up injection. | ||
| WEPC078 | Eddy Current Septum Magnets for Booster Injection and Extraction and Storage Ring Injection at SSRF | 2177 |
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| There are 6 in-vacuum eddy current septum magnets used for injection and extraction in the SSRF booster and storage ring. The booster extraction thick septum magnets generate magnetic field over 1 Tesla, special attentions were paid to coils and their support design because of the shock force and the high heat which is hard to be dissipated in vacuum environment. The good transverse homogeneity in the gap has been achieved by careful design, precise machining and accurate assembly. An extremely low leakage field on the stored beam is another key feature of these magnets thanks to the high permeability Mu metal. Magnetic field measurement was conducted with both point coil and long integral coil, and the results agreed well with the OPERA-2d/3d simulations. An inner tube with RF finger flanges at each end is added to keep the continuity of impedance for the circulating beam. There is no vacuum separation between the inner tube and magnet chamber. | ||
| WEPC079 | Elettra Booster Commissioning and Operation | 2180 |
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The new injector, consisting of a 100MeV linac and a 2.5GeV booster synchrotron, replaced the old limited energy 1.2GeV linac by the end of 2007*. The paper reports on its commissioning phases and results together with its present status of operation.
*"Overview of the Status of the Elettra Booster Project", WEPC090, these proceedings. |
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| WEPC081 | Improvement on Pulsed Magnetic Systems at SOLEIL | 2183 |
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| Two "machine study" kicker systems have been designed, built and installed on the storage ring of SOLEIL to kick the stored beam in the horizontal and the vertical planes, in order to investigate the non-linear dynamic of the ring with different insertion devices configurations. This article will describe the different aspects of the design of the two magnets and vacuum chambers, and of their fast high current pulsed power supplies, working with high voltage switches based on MOS transistors. The electrical and magnetic measurements will be presented. The second part of the paper will describe the modifications brought to the thick septum magnet system of the ring injection, in view to reduce the stray field seen by the stored beam. It also presents the different tunings performed on the four injection kickers, in order to reduce the amplitude of the residual bump along the ring down to a very low level. Theses adjustements are aimed to minimize the disturbances on the stored beam when operating the Synchrotron in "Top Up" injection mode. | ||
| WEPC082 | Technical Considerations of the TPS Linac | 2186 |
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| The technical considerations of the TPS (Taiwan Photon Source) linac will be presented in this report. A 150 MeV turn-key linac is chosen in this case in order to provide the ease of injection into the booster in which the electron energy will be raised up to 3 GeV. This linac will be similar to that equipping at recently commissioned synchrotron light sources. The major beam parameters are derived from the booster and storage ring injection requirements. The beam diagnostics arrangement for linac commissioning purpose will be briefly described. | ||
| WEPC085 | Matching with Space Charge | 2192 |
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| This paper explores the possibility of performing matching in the presence of space charge to an acceptable and useful level. Space charge gives rise to a mismatch for beams at low energies. This mismatch can be very harmful for certain applications, for example the tomography diagnostic of the PITZ2 test line. In this case, the Twiss parameters at the start of the tomography section have to be as close as possible to the design ones. As can be shown by a thin lens approximation, all the Twiss parameters at the start of the tomography section are fully determined, as is the quadrupole strength, once the length of the FODO cells is chosen. With the presence of space charge it is necessary to introduce a modification to the original matching, itself performed with a standard optimizing routine. The idea is that this modification can only compensate for the linear part of space charge and it does so by changing the quadrupole strengths. The theory is verified by using an very simple test line consisting of just two quadrupoles and modeling it using GPT (General Particle Tracer). This results in modified values for the quadrupole strengths to accommodate the effect of space charge. | ||
| WEPC087 | New Preinjector for the ESRF Linac | 2195 |
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| A new preinjector of the 200 MeV Linac is under manufacture at the ESRF. Two operation modes are foreseen, a short pulse of 1ns-.4nC and a long pulse of 1000ns-10nC. The new triode type thermionic 100 Kev gun has been characterized experimentally. The transverse and longitudinal phase space measurements are compared with simulations. The design and the expected performance of the final set-up which includes vertical deflecting plates, pre-bunching and bunching sections will be presented. | ||
| WEPC089 | Status of the NSLS-II Injection System Design | 2198 |
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| NSLS-II is a new ultra-bright 3rd generation 3GeV light source planned to be built at Brookhaven National Laboratory. The design of this facility is well under way. The requirement for the compact injector complex which has to continuously provide 3GeV electrons for top off injection into the storage ring is very demanding: high reliability, low loss, relatively high charge (10nC). The injector consists of linear accelerator, a full-energy booster, as well as transport lines and injection straight section. A large three dimensional dynamic aperture through the entire acceleration cycle in the booster synchrotron is required. Tolerances on pulsed magnets for the beam transfer are very tight in order to minimize injection losses and disturbance of the stored beam in the main ring. The components of the injector are optimized for high reliability and availability. In this paper we give an overview of the NSLS-II injector, discuss status, specifications and design challenges. | ||
| WEPC090 | Overview of the Status of the Elettra Booster Project | 2201 |
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| The Elettra Booster Project is in its final phase. The 100 MeV linac pre-injector and the 2.5 GeV booster were constructed and installed on schedule and within the foreseen budget. Elettra was shut down during the last autumn to switch from the old linac injector to the new booster. The new 2.5 GeV transfer line was successfully connected to the storage ring by December 2007. During the same period the booster commissioning was started. Operation for users of the light source, with the booster as injector, is scheduled in March 2008. An overview of the booster systems and of the current status of its commissioning and operation is presented and discussed here. | ||
| WEPC091 | Beam Injection by Use of a Pulsed Sextupole Magnet at the Photon Factory Storage Ring | 2204 |
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| We will install a pulsed sextupole magnet (PSM) in order to test a new injection system for the top-up injection at the Photon Factory storage ring (PF ring) in the spring of 2008. A parabolic magnetic field of the PSM can give an effective kick to the injected beam that passes a distant region from the field center. And there is little modulation of the orbit of the stored beam because it passes around the center of the PSM. To achieve the beam injection at the PF ring, the PSM has a length of 0.3m, a magnetic field of 400 Gauss at a peak current of 3000A and a pulse width of 2.4μsec in a half-sine form. We already made the PSM and measured the magnetic field. We will report the result of the PSM beam injection at the PF ring. | ||
| WEPC092 | A Pulsed Quadrupole Magnet Injection at the PF-AR Storage Ring | 2207 |
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| We have examined a beam injection system that used a pulsed quadruple magnet (PQM) at the PF-AR storage ring since the spring of 2004. The system is operating well and the accumulation of the beam up to 60mA in the single bunch operation is possible by the current state. The beam injection system that uses the PQM does not require a conventional injection bump orbit, and has the feature that only one PQM in the injection part is needed. An injected beam is kicked to be proportional to the distance from the center and captured afterwards. On the other hand, the pulse kick hardly influences the stored beam at the magnetic field center of the PQM. We report on the result of collecting the basic data of the influence on the PQM beam injection at the PF-AR storage ring. | ||
| WEPC093 | Finalized Design of the Pulsed Magnets and their PS for SESAME Ring Injection | 2210 |
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| The design of the SESAME storage ring injection pulsed magnet systems have been improved in order to take benefit of the most recent realizations in Synchrotrons. These pulsed systems are optimised for the injection into the 2.5GeV storage ring of the 800 MeV electrons beam prepared by the Booster. The septum magnet is based on a direct driven septum technology, out of vacuum, with a thin vacuum chamber of rectangular cross section permitting to get a good field transverse homogeneity. The four kicker magnets will be of the window frame geometry, around a racetrack alumina vacuum chamber, integrating a forced air cooling in order to avoid significant thermal heating due to the stored beam. These magnets can be opened for backup and will be completely CEM shielded. Their pulsed power supplies will be built based on solid-state HV switches, even for short half-sine pulses generation. | ||
| WEPC094 | Thermo-Cathode RF Gun for BINP Race-Track Microtron-Recuperator | 2213 |
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| In 2007 the thermo-cathode RF gun for the Budker INP energy recovery linac (ERL) was designed. The RF gun is capable to emit the electron bunches with the energy of 300 keV, average current of 100 mA, and repetition frequency of 90 MHz. The new injector is adapted to the existing RF system for beam bunching, accelerating and injecting to the linac of the microtron. Its advantage is the absence of high potential of 300 kV at the control circuits of the cathode; therefore the maintenance is simplified. Also due to the absence of the cathode back bombardment by residual gas ions in the RF cavity, the lifetime of the cathode is increased and the obtaining of the repetition frequency up to 90 MHz becomes feasible. In the paper the main characteristics of the injector, its design and results of beam dynamics calculations with optimised regimes are presented. | ||
| WEPC095 | Progress in Raising the Energy of the CAMD Linac to 300 MeV | 2216 |
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| The possibilities and methods for higher energy injection at CAMD have been discussed previously. All components of the former HELIOS 1 linac have now been transferred to CAMD from Jefferson Laboratory. It is planned to reconfigure the CAMD injector linac by installing one of the HELIOS accelerating sections in addition to the two existing CAMD sections, thereby increasing the energy to 300MeV. The optimum arrangement for installing the 300 MeV linac in the existing tunnel has been established. Meanwhile, the arrangements and upgrades of sub-systems are being prepared, simulations of the electron beam trajectory by MATLAB based linear accelerator program are being made, and recommissioning the major HELIOS linac components is underway. In the paper, the detailed technical design of the 300 MeV linac is proposed, the key parameters of the linac are presented, and the benefits of 300 MeV injection to the CAMD synchrotron radiation light source are mentioned. |