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| MOPCH071 | Optimization of Optics at 200 MeV KEK-ERL Test Facility for Suppression of Emittance Growth Induced by CSR | CSR, emittance, dipole, insertion | 190 | ||
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Energy Recovery Linac (ERL) gets a lot of attention as a next period light source instrument. To produce high-brightness and short pulse synchrotoron lights, it is necessary to pass through high current and short bunch electron beams to the insertion part of ERL with keeping the low emittance and the low energy spread. However, it is challenging because Coherent Synchrotorn Radiation (CSR) generated at bending magnets is potential sources of the emittance growth which is enomous especially for high current, short bunch and a low energy beam. Therefore, it is benefit to a gradual bunch compression in the arc after accelerating the beam up to the full energy. The beam optics and lattice design of 200MeV ERL Test Facility is optimized to suppress the emittance growth caused by CSR at the arc section on two conditions, high-current mode (100mA, 1psec) and short bunch mode (0.1psec) similar to 5GeV ERL facility proposed by Cornell University.
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| TUPCH055 | Beam Phase Measurement of Stored Bunch | pick-up, controls, insertion, injection | 1133 | ||
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We developed a system to measure synchronous phase angles for all bunches stored in the storage ring using an oscilloscope with high sampling rate. Precise phase measurement of specific bunch is required from the synchrotron radiation (SR) users, especially from the time resolved spectroscopy users. In a pump and probe experiment, the trigger timing for pumping laser should be precisely adjusted to the probe SR light. The timing of SR light is affected by the accelerating RF voltages, filling pattern, bunch currents, gap positions of insertion devices and so on. At the SPring-8, the bunch currents and the synchronous phase angles for all stored bunches can be measured within 30seconds using newly developed system. The precision of the phase angle is less than 8ps. We are now preparing to deliver the information of synchronous phase angle to SR users. The detail of the measurement system and achieved performance will be presented.
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| WEPCH025 | COD Correction at the PF Ring by New Orbit Feedback Scheme | feedback, simulation, insertion, electron | 1978 | ||
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When we correct the global COD (closed orbit distortion), if we use the modified conversion matrix calculated by the eigen vector method with constraint conditions (EVC), the local orbit correction can be simultaneously done to fix the light source point in the insertion device. In the EVC, the local orbit correction is combined to the global orbit correction by the Lagrange's undetermined multiple method. In this paper, we show the machine study results at the PF Ring.
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| WEPLS133 | Stability Study of Superconductor Magnet Power Supplies at TLS | power-supply, controls, superconducting-magnet, insertion | 2688 | ||
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In this paper, performance of three power supplies schemes driving the newly-developed Superconducting Wave Length Shifter Magnet at TLS is investigated. Due to the inherent structure of the Superconducting Magnet, the main and two accessory trimming power supplies are physically correlated with each others. Due to the inherent structure, in order to achieve high performance control of the magnet, slew rate control of the main power supply and the proper operation sequence have to be properly managed, otherwise, small current disturbance can occurs, which may disgrade the stability of the performance of Superconducting Magnet.
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| THPCH062 | Collective Effects in the Storage Ring of Taiwan Photon Source | impedance, storage-ring, insertion, damping | 2928 | ||
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A new 3- 3.3 GeV synchrotron light source is proposed and named the Taiwan Photon Source (TPS). The TPS design has a natural horizontal emittance less than 2 nm-rad and low emittance coupling, which results in small beam size. The nominal bunch length in TPS storage ring is much shorter compared to the existing Taiwan Light Source, that makes the issue of parasitic heating more significant. Several small-gap insertion devices are planned to provide extremely bright x-ray photon beam. Those design features have impacts on collective beam instabilities. A preliminary study of collective effects in the TPS storage ring is presented.
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| THPCH134 | Development of Insertion Device Magnetic Characterization Systems at LNLS | insertion, wiggler, controls, synchrotron | 3113 | ||
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This paper describes a set of magnetic measurement systems employed in the development of insertion devices at LNLS (Brazilian Synchrotron Light Source). They are: rotating coil (which can also operate as a flip-coil), spatial field mapping using Hall probes and parallel coils (Helmholtz configuration) for magnetic blocks characterization. Although such techniques are well established, strict specifications imposed by the beam dynamics on the magnetic field quality, led to a detailed analysis of their sources of error and their minimization. All three systems have already been tested and showed excellent accuracy and repeatability when compared to typical values found in the literature.
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| THPCH171 | Control System of the Superconducting Insertion Device at TLS | controls, power-supply, insertion, cryogenics | 3197 | ||
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There are three superconducting insertion devices installed at Taiwan Light Source. Two is under construction. These insertions enhance hard X-ray production to satisfy the research requirement of X-ray community. The control system is implemented to support the operation of all these superconducting insertion devices. The control system coordinate the operation of the main power supply and the trimming power supply to charge/discharge the magnets and provide essential interlock protection for the coils and vacuum ducts. Friendly user interface supports routine operation. Various applications are also developed to aid the operation of these insertion devices. Design consideration and details of the implementation will be summary in this report.
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| THPLS011 | Operation and Recent Development at the ESRF | feedback, ESRF, undulator, insertion | 3290 | ||
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We report on the achieved performance of the ESRF storage ring as well as developments accomplished or underway. A new hybrid filling mode based on groups of bunches and a 4-bunch filling pattern are now delivered to the users. Following the increasing demand of users for beam stability, the fast orbit feedback has been upgraded. The installation of 5 m-long, 8 mm vertical aperture NEG coated aluminum chambers is progressing at a rate of one chamber per shutdown. The increase in current from 200 to 300 mA is being prepared; however, operation in this mode is still impaired by HOM driven longitudinal instabilities. To overcome this difficulty, a longitudinal feedback is being commissioned. HOM damped cavities are also under study to possibly replace the existing five-cell cavities. The policy of preventive maintenance has been continued. However, in 2005 the machine availability was affected by water leaks occurring on front-end absorbers and on one dipole crotch absorber. The crotch absorbers suffer all from the same erosion process that could be delayed by a systematic vertical realignment, leaving time for procurement and replacement of the entire pool.
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| THPLS017 | Orbit Stability in the 'Low Alpha' Optics of the BESSY Light Source | storage-ring, insertion, synchrotron, optics | 3308 | ||
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Running the light source during dedicated shifts in the so-called 'low alpha' mode, BESSY serves two major user groups: THz experiments take advantage of intense, coherent synchrotron radiation (CSR) generated by the short bunches. Time resolved experiments appreciate the very short, high intensity VUV and x-ray pulses in the ps range that help, e.g., prepare the high resolution, low intensity fs-slicing experiments. In the 'low alpha' mode, the sensitivity of the storage ring with respect to energy and horizontal orbit is increased by orders of magnitude while the user experiments require the same beam stability as in 'normal' mode. In this paper an overview of the operational conditions of this specific user mode, the stabilization measures taken, observations and available diagnostic results as well as the achievements and shortcomings of the adapted slow orbit feedback are given.
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| THPLS031 | Elettra Top-up Requirements and Design Status | injection, electron, insertion, ELETTRA | 3350 | ||
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Elettra is a 2.5 GeV third generation light source in operation since 1993. To provide more stable beams to the users, we plan to operate in the so-called top-up injection mode. The first step is the substitution of the present 1GeV linac by a 100 MeV pre-injector linac and a fast cycling 2.5 GeV synchrotron booster foreseen to be in operation in 2007*. The present paper will report on the requirements for the top-up operation in terms of radiation safety, diagnostics H/S, timing, modality, etc. and the design status. In particular, a new BPM system, based on the log-ratio detectors, has been successfully commissioned on the present transfer line and linac and is ready to be deployed on the new injector and to be used by the new foreseen shot to shot transfer line booster to storage trajectory feedback system. Furthermore, in order to flatten the storage ring filling, the top-up charge will be integrated where needed. Preliminary measurements on the bunch by bunch measurement methods of the storage ring bunch charge are reported.
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*“Elettra New Full Energy Injector Status Report”, these proceedings. |
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| THPLS032 | ELETTRA New Full Energy Injector High Level Software | controls, lattice, optics, ELETTRA | 3353 | ||
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The control system for the new full energy injector* will be entirely based on Tango with an object oriented distributed architecture. The availability of the new and modern software platform led us to design and develop a new high level software framework which allows a model-based accelerator control. The new design is fully object oriented and follows a layered approach. The main layers provide a set of different views or abstractions of the underlying accelerator: field layer, machine layer, and optics layer. The field layer handles all the access and communications with the actual devices of the accelerator, e.g., power supplies, instrumentation, etc. The machine layer handles the machine layout description, functional constraints like the association of a string of magnets with one power supply, and the conversion from actual values acquired from the field into values meaningful to beam dynamics problems. The optics layer performs all the actual calculations concerning the beam like beta functions, damping times, etc. An important characteristic of the new library is the unified management of all the needed calibrations and configurations by means of a relational database.
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*“Elettra New Full Energy Injector Status Report”, these proceedings. |
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| THPLS039 | Upgrade and Current Status of the PF Ring Vacuum System | vacuum, photon, insertion, controls | 3371 | ||
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The vacuum system for the KEK Photon Factory (PF) was extensively modified in 2005 as part of the PF ring straight-sections upgrade project. This project required replacements of the quad magnets in both northern and southern straight-sections that account for nearly two-thirds of the whole circumference. Therefore, the vacuum ducts in these new quad magnets (Q-ducts), as well as the vacuum ducts in their related bend magnets (B-ducts), needed to be replaced. The new Q-ducts have a narrower cross-section and are equipped with new 4-electrode beam position monitors, and the new B-ducts are furnished with new distributed ion pumps. After the installation of these vacuum chambers, we omitted the thermal in-situ baking, anticipating that beam scrubbing would provide more efficient cleaning. Furthermore, even pre-baking before installation was not performed for the chambers in the northern half in order to evaluate the effect of the pre-baking during the early period of the commissioning. Details of these modifications, as well as the current status of the new vacuum system, will be presented.
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| THPLS117 | In-vacuum and FEL Undulators at Danfysik | undulator, SLS, insertion, FEL | 3553 | ||
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Danfysik has recently designed and produced two in-vacuum insertion devices. The first device is a 19 mm period device made for the Swiss Light Source and the second is a 20 mm period device for SOLEIL. Both are hybrid undulators with Samarium Cobalt magnets where the SLS device is made with steel poles while the SOLEIL undulator is optimized for high peak field using Vanadium Permendur poles and relative large magnet blocks. A quasi-periodic undulator has been built for FEL applications at the FOM-Institute for Plasma Physics. The device is based on a standard pure permanent undulator design but then converted into a quasi-periodic device. The magnetic performance of the device was in excellent agreement with theoretical calculations with high suppression of the 3. and 5. harmonics. A conventional undulator has also been built for FEL applications at FZR Rossendorf. A high degree of software assistance and automation has been developed for the magnet mounting, shimming and magnetic testing of the insertion devices. This technique reduces the shimming time significantly, reduces the need for highly trained personnel and results in superior magnetic performance.
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| THPLS118 | Status of the SOLEIL Insertion Devices | undulator, SOLEIL, insertion, polarization | 3556 | ||
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SOLEIL is the French 2.75 GeV synchrotron radiation light source of low emittance under construction near Paris. It will provide high intensity photons covering a wide spectral range from the IR to the hard x-rays. The storage ring commissioning will start in April 2006, and the first photons in the beam lines are expected during summer 2006. The first set of Insertion Devices (ID) will be installed before the commissioning or within the first year of operation of the machine. They consist of one 640 mm period and three 256 mm period electromagnetic helical undulators, three 80 mm period Apple II type undulators, and three 20 mm period in-vacuum undulators. All these ID's make use of a wide panoply of technical solutions for generating various types of magnetic fields. Magnetic and conceptual designs were performed by SOLEIL, and the technical realisation was carried out together with the different manufacturers. The design specificities of the different types of ID's and the magnetic field characterisation and optimisation will be reported. The first commissioning on the beam of these undulators will be described.
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| THPLS120 | Tracking Simulations and Dynamic Multipole Shimming for Helical Undulators | multipole, simulation, undulator, insertion | 3562 | ||
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Symplectic and fast tracking simulations of an APPLE type undulator for the BESSY II storage ring are presented. The simulation is based on a multiple harmonic decomposition of the magnetic field and on a generating function approach. Because of the relatively large undulator period length of 112 mm, corrections of the dynamic multipoles are required to achieve a good dynamical aperture.
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| THPLS124 | The Second Generation of Superconductive Insertion Devices for ANKA | undulator, wiggler, insertion, radiation | 3574 | ||
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After the superconducting undulator SCU14 was installed and successfully started operation at ANKA in spring 2005, a second generation of superconducting insertion devices for ANKA is under development. The ANKA soft x-ray analytics beamline WERA is planned to be equipped with a superconducting elliptically polarising undulator (SCEPU) with electrically tunable polarisation, and a superconducting combined undulator/wiggler (SCUW) capable of period tripling will serve as the source for the planned ANKA imaging beamline. In this paper the studies on the ANKA superconducting EPU and the status of the SCUW-project will be reviewed.
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| THPLS126 | Construction and Testing of a Pair of Focusing Undulators for ALPHA-X | undulator, electron, focusing, insertion | 3580 | ||
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ALPHA-X is a four-year project shared between several research groups in the UK to build a laser-plasma accelerator and produce coherent short-wavelength radiation in an FEL. A pair of undulators for the project have been designed and built by ASTeC at Daresbury Laboratory. The undulators are 1.5m long, 100 period permanent magnet devices with a minimum gap of 3.5mm, a peak field of 0.7T and a two-plane focusing design. The devices were modelled using RADIA, and data from the magnet block manufacturer was used to sort the blocks. To optimise the trajectory in the real devices, magnetic testing (using Hall probe and flipping coil techniques) and block swapping has been performed in Daresbury's dedicated insertion device test facility. The measurements agree well with the models, and the undulators will perform well within specification.
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| THPLS128 | Overview of Diamond IDs for Phase 1 | DIAMOND, wiggler, insertion, factory | 3586 | ||
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Diamond Light Source is a 3GeV synchrotron currently under construction in the UK, which will be operational in early 2007. It is a third generation light source comprising 22 usable straight sections for insertion devices. Phase 1 of beamline construction will include eight Insertion Devices: five PPM in-vacuum undulators, two APPL·10-2 devices to be installed in the same straight, and one 3.5T superconducting wiggler. This paper describes the current status of construction and magnetic measurements for each of the Phase 1 devices.
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| THPLS135 | The Study of Errors of ALBA Fixed Stretched Wire Bench | pick-up, alignment, undulator, insertion | 3601 | ||
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The new synchrotron radiation source ALBA to be built nearby Barcelona is planned to start operation in 2009. The facility includes a laboratory for magnetic measurements laboratory devoted to IDs. The stretched wire measurement technique is widely used to obtain magnetic field integrals. This technique is based upon the displacement of a stretched wire relative to the magnetic structure to be measured. In the most usual configuration, the magnets are kept fixed while the wire is moved. This arrangement is especially well suited for measuring big structures such as full undulators or its jaws. In contrast, in the fixed stretched wire configuration the magnetic structure is moved relative to a stationary pick-up coil with a straight segment. This layout is convenient for the measurement of small units, such as individual magnet blocks or magnetic modules. These measurements allow characterising the inhomogeneities of the building blocks of an undulator. In this paper we present an exhaustive analysis of error sources and tolerance requirements for a particular design of a fixed stretched wire bench made at ALBA, based both in the ESRF, SOLEIL and BESSY previous existing designs.
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| THPLS136 | Magnetic Field Multipole Measurement with Hall Probe | multipole, undulator, insertion, simulation | 3604 | ||
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When assembling an insertion device before shimming, sorting algorithms are used to reduce the field errors by choosing the best arrangement of magnetic blocks. In order to carry it out, magnets to be placed in the array are measured with the Helmholtz coil. This yields the magnetic dipolar moment of each one. In fact, Helmholtz coil measurements assume a dipolar filed for each block. The development of narrow gap insertion devices yields a growing interest in the effect of magnetic inhomogeneities. Magnetic inhomogeneities introduce multipolar terms that are added to those corresponding to the multipole development of an ideal magnetic source. However, magnetic inhomogeneities are not measured so far with the Helmholtz coil, because it evaluates the magnetic field far from the magnet, and the multipolar terms decay faster than the dipolar with distance. In order to take into account inhomogeneities, a new approach could be used, based on the measurement of multipoles corresponding to each block. In this paper we propose a method for the fast measurement of the multipoles corresponding to an arbitrary magnetic block, using a Hall probe scanning along a single straight line.
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| THPLS137 | Insertion Devices for the MAX IV Light Source | undulator, storage-ring, insertion, radiation | 3607 | ||
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The foreseen insertion devices and expected brilliance for the MAX IV light source are presented. The planned MAX IV light source consists of three low emittance storage rings and a 3 GeV linac. The linac is used as a full energy injector. The three storage rings will be operated at 700 MeV, 1.5 GeV, and 3.0 GeV, which makes it possible to cover a large spectral range from IR to hard X-rays with insertion devices optimised for each storage ring.
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