| Paper | Title | Other Keywords | Page |
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| MOP032 | PAL-XFEL Magnet Power Supply System | controls, power-supply, dipole, status | 87 |
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| This paper presents an overview of the magnet power supply(MPS) for the PAL-XFEL. The number of total MPS is 628 and they will be installed along the accelerator and the undulator sections. The power capacity of the MPS was ranging from about 1 A to 300 A. These MPSs were required to meet the high stability that was subjected from the beam dynamics specifications. This paper described the overall MPS requirements, MPS assembling, test process, control scheme, installation plan and so on. | |||
| MOP033 | Design, Fabrication, and Performance Tests of Dipole and Quadrupole Magnets for PAL-XFEL | dipole, multipole, undulator, optics | 90 |
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| PAL-XFEL is now being constructed in Pohang, Korea. This facility will consist of a 10 GeV linac and five undulator beamlines. As the first phase we will construct one hard X-ray and one soft X-ray beamlines which require 7 different families of dipole magnets, and 11 families of quadrupole magnets. We are designing these magnets with considering the efficient manufacturing and the proper power supplies. In this presentation, we describe the design features of the magnets, the manufacturing, and the thermal analysis with the test results. | |||
| MOP040 | General Strategy for the Commissioning of the ARAMIS Undulators with a 3 GeV Electron Beam | undulator, electron, alignment, photon | 107 |
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| The commissioning of the first SwissFEL undulator line (Aramis) is planned for the beginning of 2017. Each undulator is equipped with a 5-axis camshaft system to remotely adjust its position in the micrometer range and a gap drive system to set K-values between 0.1 and 1.8. In the following paper the beam-based alignment of the undulator with respect to the golden orbit, the definition of look-up tables for the local correction strategy (minimization of undulator field errors), the fine-tuning of the K-values as well as the setting of the phase shifters are addressed. When applicable both electron beam and light based methods are presented and compared. | |||
| MOP041 | Summary of the U15 Prototype Magnetic Performance | undulator, vacuum, electron, photon | 111 |
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| The first undulator prototype (U15) was assembled and magnetically tested. The instrumentation and the algorithms developed for the undulator optimization are presented and a comparison among different approaches is reviewed. The magnetic measurement results before and after the installation of the vacuum components are discussed. The summary of the undulator test with 100 MeV electron beam is presented and the impact of the radiation on the magnetics is addressed. | |||
| TUP093 | A Beam Test of Corrugated Structure for Passive Linearizer | simulation, electron, linac, controls | 593 |
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| A dechirper which is a vacuum chamber of two corrugated, metallic plates with adjustable gap was successfully tested at Pohang, in August 2013. Another beam test was carried out to test the same structure to see if the corrugated plates may work as a linearizer. The test result will be presented together with the simulation result. | |||
| THP002 | Beam Energy Management and RF Failure Compensation Scenarios for the European XFEL | linac, klystron, operation, optics | 672 |
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| The operation of complex systems as the driver linacs for free-electron-lasers is limited by the reliability of the individual components. Failures of RF systems can therefore constrict FEL availability. Typically reserves are included in the overall linac voltage capacity to allow for redistribution of acceleration in case of an RF failure. However, such redistributions of the acceleration of the linac affects the beam dynamics of the machine. While the effects on the optics can easily be compensated by rescaling of the quadrupole magnet strength, the bunch compression set-up requires a more involved investigation. In this paper we discuss studies for an energy management system for the European XFEL. | |||
| THP013 | Slice Emittance Measurement using RF Deflecting Cavity at PAL-XFEL ITF | emittance, cavity, electron, gun | 707 |
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| One of key characteristic for operating PAL-XFEL is the time-dependent transverse properties of a bunch, slice emittance. To achieve the design FEL performance of PAL-XFEL a slice emittance of 0.4 mm mrad at 0.2 nC is required. An Injector Test Facility (ITF) was constructed to study beam properties. In addition to projected emittance measurement, slice emittance measurement is being done using a transverse RF deflecting cavity. We presents results of slice emittance measurement at ITF and future plan for the optimization of operating condition. | |||
| THP026 | Design Study of LCLS Chirp-Control with a Corrugated Structure | wakefield, emittance, dipole, simulation | 748 |
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The purpose of this paper is to investigate the use of flat metallic plates with small corrugations as a passive dechirper, studying its effects on beam dynamics. Similar systems have been tested in Pohang and Brookhaven at relatively low energies (~100 MeV) and with relatively long bunches (>1ps) [*,**]. Four meters of such a structure are being machined by Radiabeam Systems for use in the LCLS with a high energy and femtosecond electron beam. In this paper we use a field matching program to obtain the longitudinal and transverse wakes for the purpose of the LCLS dechirper design. In addition, we fit the longitudinal wake to simple functions, so that one can obtain the wake without resorting to the field matching program. Since the transverse wakes–both dipole and quadrupole wakes–are strong, we include beam dynamics simulations to find the tolerances for injection jitter and misalignment in the LCLS.
* P. Emma, et al. PRL 112, 034801 ** M. Harrison, et al., NaPAc 2013, Pasadena, USA |
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| THP033 | Mechanical Design for a Corrugated Plate Dechirper System for LCLS | wakefield, vacuum, controls, electron | 785 |
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Funding: This work is supported by Department of Energy grant number DE-SC0009550. RadiaBeam Systems is developing a novel passive chirp removal system using corrugated plates as studied by Bane and Stupakov.* Following on from low-energy experiments at BNL-ATF,** RBS will install a much larger and powerful system for removing the chirp from the 3-GeV beams in the LTU section at LCLS. The larger plates will present new challenges in the areas of manufacturing and mechanical control. In this paper we review the requirements for the dimensions of the corrugated plates for proper operation and the infrastructure necessary for precisely placing the plates so as not to adversely disrupt the beam. * K. Bane, et al "Corrugated Pipe as a Beam Dechirper," SLAC-PUB-14925, 2012 ** Harrison, M., et al "Removal of Residual Chirp in Compressed Beams Using a Passive Wakefield Technique." NaPAC13, 2013 |
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| THP088 | Comparison of Quadrupole Scan and Multi-screen Method for the Measurement of Projected and Slice Emittance at the SwissFEL Injector Test Facility | emittance, diagnostics, optics, FEL | 941 |
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| High-brightness electron bunches with small transverse emittance are required to drive X-ray free-electron lasers (FELs). For the measurement of the transverse emittance, the quadrupole scan and multi-screen methods are the two most common procedures. By employing a transverse deflecting structure, the measurement of the slice emittance becomes feasible. The quadrupole scan is more flexible in freely choosing the data points during the scan, while the multi-screen method allows on-line emittance measurements utilising off-axis screens in combination with fast kicker magnets. The latter is especially the case for high-repetition multi-bunch FELs, such as the European XFEL, which offer the possibility of on-line diagnostics. In this paper, we present comparative measurements of projected and slice emittance applying these two methods at the SwissFEL Injector Test Facility and discuss the implementation of on-line diagnostics at the European XFEL. | |||