| Paper | Title | Page |
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| TUPCH099 | Development of HOM Damped Copper Cavity for the ESRF | 1244 |
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At the ESRF, HOM driven longitudinal coupled bunch instabilities are currently avoided up to the nominal beam current of 200 mA by precisely controlling the cavity temperatures and thereby the HOM frequencies of the existing five-cell copper cavities. A bunch-by-bunch feedback is presently being commissioned in order to increase the maximum stored current. In parallel, normal conducting strongly HOM damped cavities are under study to possibly replace the five-cell cavities. The design is based on a scaling of the single cell EU cavity*: a pillbox geometry with nose cones and three attached ridged waveguides loaded by ferrites for effective HOM damping. We report on the electromagnetic simulation making use of the 3D codes HFSS and GdfidL. They allowed optimizing the shape of both cavity and dampers, including electromagnetic absorbing material with frequency dependent parameters.
*E. Weihreter et al. A Ridged Circular Waveguide Ferrite Load for Cavity HOM Damping, this conference. |
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| WEPLS065 | The Effect of Vaccum Vessel Permeability on the Field Quality within Dipole and Quadrupole Magnets at the Energy Recovery Linac Prototype (ERLP) at Daresbury Laboratory | 2529 |
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| The Energy Recovery Linac Prototype (ERLP) is currently under construction at Daresbury Laboratory in the UK and will serve as a test bed for the investigation of technologies and beam physics issues necessary for the development of Daresbury Laboratory's Fourth Generation Light Source (4GLS) proposal. To assist with the material specification of the vacuum vessels, analyses have been done on the effect of vessel permeability on the magnetic field quality within quadrupole and dipole magnets. It is found that for dipoles where the specified maximum relative dipole field variation over the good field region is ± 1x 10-4 or for quadrupoles where the specified maximum relative gradient variation is ±1 1x10-3, the transverse size of the good field region decays unacceptably for relative permeability > 1.006. However, for the dipoles where the specified maximum relative dipole field variation is ± 1x10-3, the decay of the good field region is more gradual and would safely permit a material with relative permeability >1.006 to be used for the vacuum vessel within these dipoles. | ||
| WEPLS066 | Harmonic Measurement and Adjustment of Diamond Quadrupoles | 2532 |
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| The 254 quadrupole magnets for Diamond, manufactured by Tesla Engineering Ltd, were measured for harmonic content to a level around 1 part in 104. In order to meet the demanding requirements on field quality, procedures were then developed to adjust the relative positions of the magnet quadrants such that the desired harmonic levels were achieved. This process was integrated into the analysis software so that the needed changes were specified. The measurements were performed on a seven-coil rotating coil rig, which also enabled the alignment of the magnet in five spatial degrees of freedom to the specified accuracy. In this report we describe the measurement and correction procedures and present a summary of the results that were obtained. | ||
| WEPLS067 | Magnets for the 3 GeV Booster Synchrotron for the Diamond Light Source | 2535 |
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| The Diamond Booster is a full energy injector for the Diamond Storage Ring. It is designed to accelerate electrons from 100 MeV to 3 GeV at a 5 Hz repetition rate. The lattice is a missing dipole FODO lattice consisting of 22 unit cells with 36 dipoles, 44 quadrupoles, 28 sextupoles and 44 correctors, distributed around a circumference of 158.4 m. The dipole field will be ramped from 0.026 T at injection to 0.809 T at 3 GeV; the quadrupoles will have a maximum operating gradient of 15T/m. The initial design of pole tip profiles was carried at Diamond, with the magnets then manufactured by DANFYSIK A/S as part of preassembled girder units (44 in total), complete with vacuum vessels. High quality was required to meet the accelerator physics requirements of alignment, positioning accuracies and field tolerances over the required good field apertures. Materials, ramp rates and field range have been selected to obtain almost linear response during magnet ramping. This paper describes the main features of the magnetic designs and measurement results; the magnets have now been delivered and installed at Diamond. | ||
| WEPLS068 | The IASA Magnetic Field Mapping (MFM) Project | 2538 |
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| The design and development of an automatic magnetic field mapping device as supporting equipment for the 10 MeV CW-Linac and its transport system at the Institute of Accelerating Systems and Applications (IASA) is presented. The MFM project aims to totally automate the operation of mapping room temperature magnetic field sources, reconstruct the 3D-field shape and reveal nonlinearities in the fridge field regions. The positioning system covers an area of 50x50 cm2 with an accuracy of less than 20 ?m in both axes; magnetic field measurements, mainly based on a Hall probe, can reach in precision the 1x 10-4 value. Several software tools for the visualization of the measured fields and for a direct comparison with theoretical estimates are also presented. | ||
| WEPLS070 | The Elettra Booster Magnets Construction Status | 2541 |
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| The third generation light source ELETTRA has been in operation since 1993. A new 2.5 GeV full energy booster injector has been approved and founded last year. It will replace the existing linear injector limited to a maximum energy of 1.2 GeV. During last year, after having completed the specifications and the preliminary magnetic and mechanical design, the orders for all the magnets were assigned to two European firms. The paper reports on the magnets' construction status and the requested specifications. | ||
| WEPLS071 | Design Method for a Large Aperture Opposite-field Septum Magnet | 2544 |
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| A novel design septum for Japan Proton Accelerator Research Center (J-PARC) delivers high intensity 3GeV proton beam to the 50GeV main ring is presented. The project requires the construction of the large aperture septum to accommodate the large size and high intensity injection beam. As there limitations due to the lattice size and restricted installation space, the septum must provide a large kick angle to the injection beam. Sufficient clearance between the circulating beam and the injection beam is also needed to reduce the beam loss to an acceptable level to avoid the serious radiation problem. To meet these challenging requirements, a large aperture, thin septum, opposite-field septum magnet has been developed. In this paper, we present the detail studies done for the optimization of the magnet, including DC and pulse magnet. | ||
| WEPLS072 | Results of Field Measurements for J-PARC Main Ring Magnets | 2547 |
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| The mass production of J-PARC main ring magnets had been completed till the end of fiscal year 2004. Those magnets consists of 97 bending magnets with 6-m in length, 216 quadrupole magnets with 11 families and 72 sextupole magnets. We have been measured the magnetic field for all of these magnets and we will finish it in March, 2006. The obtained distributions for the BL products of bending magnets and the GL products of quadrupole magnets are within the required tolerance limits, values of which are estimated by the beam optics for COD correction, etc. The measured multi-pole components for these magnets, and so on, will be also reported. | ||
| WEPLS073 | A Super Strong Adjustable Permanent Magnet Quadrupole for the Final Focus in a Linear Collider | 2550 |
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| An adjustable permanent magnet quadrupole has been fabricated to demonstrate its feasibility for use in the final focus of a linear collider. The supposed requirements for such a final focus lens are the tight stabilities of its integrated field gradient and magnetic center, plus it must have adjustable strength. The high temperature coefficient of the permanent magnet material NEOMAX is compensated by use of the MS-1 Fe-Ni alloy. The magnet has two concentric rings of NEOMAX. The replacement of the inner ring with a smaller diameter one is planned in order to reach the highest gradient with the current configuration of the quadrupole system; the system has to be scaled down in size to fit in a real linear collider final focus system. A precise magnetic field measurement system is also under fabrication that will be able to measure the magnetic center to a fraction of a micron. | ||
| WEPLS074 | SESAME Magnets System | 2553 |
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| In this paper the SESAME storage ring magnet system is described. The storage ring consists of 16 bending magnets with a maximum field of 1.455 T and vertical gradient of 2.79 T/m, 32 focusing quadrupoles with a maximum gradient of 16.92 T/m, 32 defocusing quadrupoles with a maximum gradient of 10.23 T/m, 32 focusing sextupoles with a maximum differential gradient of 200 T/m2 and 32 defocusing sextupoles with the maximum differential gradient of 300 T/m2. The horizontal/vertical correctors will be embedded inside focusing/defocusing sextupoles. For the quadrupole and sextupole, a design similar to ANKA has been adopted. The magnetic and electrical design of dipoles and correctors, field profile and higher order multipoles optimization will be presented. | ||
| WEPLS077 | Considerations on the Design of the Bending Magnet for Beam Extraction System of PEFP | 2556 |
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| The PEFP is designed to have two beam extraction lines at the 20 MeV end and 100MeV end for beam utilization. So, the bending magnet to extract the beam from the beam line is located among the MEBT. This implies that there is a long drift space between the focusing structures, while, from the beam dynamics study, it is recommended to make the drift space shorter. In this study, we design and compare some bending magnets to satisfy the beam dynamics requirements. | ||
| WEPLS078 | Design Study of the 30 MeV Cyclotron Magnet | 2559 |
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| Korea Institute of RAdiological & Medical Sciences (KIRAMS) has been developing a 30 MeV cyclotron that is planned to be installed at Advanced Radiation Technology Institute, Jeongeup in late 2006. The AVF (Azimuthally Varying Field) magnet of the cyclotron was designed to produce 15-30 MeV proton beam with movable stripper foil. Four directions of extractions are available with two switching magnets. The overall shape of the magnet is cylindrical. The magnet has three kinds of holes for beam injection, vacuum pumps and RF system. The valley and hill gap ratio is about 20 for higher axial focusing. The designed magnet model and its magnetic properties of the KIRAMS-30 are presented. | ||
| WEPLS080 | Magnets for the Storage Ring ALBA | 2562 |
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| The Storage Ring ALBA is a 3.0 GeV synchrotron light source under construction in Barcelona (Spain). The Storage Ring, has a circumference of 268.8 m and comprises 32 combined magnets, 112 quadrupoles, and 120 sextupoles. This paper will describe the design and the present state of these magnets. The combined magnet has a central field of 1.42 T and a large gradient of 5.65 T/m, since most of the vertical focusing happens at these combined magnets. The 112 quadrupoles have been designed for a maximum gradient of 22 T/m. The bore diameter will be 61 mm and the lengths range from 200 to 500 mm. Each quadrupole will be individually powered. The 120 sextupoles are divided in 9 families. There are two lengths of sextupoles 150 and 220 mm and the maximum sextupole gradient is 600 T/m2. The bore diameter is 76 mm. The sextupole magnets will also be equipped with additional coils for vertical steering, horizontal steering and quadrupolar skew correction. | ||
| WEPLS081 | Modifications to the SPS LSS6 Septa for LHC and the SPS Septa Diluters | 2565 |
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| The Large Hadron Collider required the modification of the existing extraction channel in the long straight section (LSS) 6 of the CERN Super Proton Synchrotron (SPS), including the suppression of the electrostatic wire septa. The newly set up fast extraction will be used to transfer protons at 450 GeV/c as well as ions via the 2.9 km long transfer line TI 2 to Ring 1 of the LHC. The girder of the existing SPS DC septa was modified to accommodate a new septum protection element. Changes were also applied to the septum diluter in the fast extraction channel in SPS LSS4, leading to the other LHC ring and the CNGS facility. The requirements and the layout of the new LSS6 extraction channel will be described including a discussion of the design and performance of the installed septum diluters. | ||
| WEPLS082 | The Septa for LEIR Extraction and PS Injection | 2568 |
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| The Low Energy Ion Ring (LEIR) is part of the CERN LHC injector chain for ions. The LEIR extraction uses a pulsed magnetic septum, clamped around a metallic vacuum chamber. Apart from separating the ultra high vacuum in the LEIR ring from the less good vacuum in the transfer line to the PS this chamber also serves as magnetic screen and retains the septum conductor in place. The PS ion injection septum consists of a pulsed laminated magnet under vacuum, featuring a single-turn water cooled coil and a remote positioning system. The design, the construction and the commissioning of both septa are described. | ||
| WEPLS083 | Consolidation of the 45-year-old CERN PS Main Magnet System | 2571 |
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| After a major coil insulation breakdown on two of the 45-year-old CERN PS main magnets in 2003, an extensive magnet consolidation program has been launched. This article reviews the analysis of the magnet state before the repair and the applied major improvements. An overview is given of the production of the new components, the actual refurbishment and the commissioning of the main magnet system after 18 months shut down. | ||
| WEPLS084 | AC Field Measurements of Fermilab Booster Correctors Using a Rotating Coil System | 2574 |
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| The first prototype of a new corrector package for the Fermilab Booster Synchrotron is presently in production. This water-cooled package includes normal and skew dipole, quadrupole and sextupole magnets to control orbit, tune and chromaticity of the beam over the full range of Booster energies (400 MeV-8 GeV). These correctors must make rapid excursions from the 15 Hz excitation cycle of the main synchrotron magnets, in some cases even switching polarity in approximately 1 ms at transition crossing. To measure the dynamic changes in the field during operation, a new method based on a relatively slow rotating coil system is proposed. The method pieces together the measured flux from successive current cycles to reconstruct the field harmonics. This paper describes the method and presents initial field quality measurements from the corrector prototype. | ||
| WEPLS085 | Study of RF Breakdown in Normal Conducting Structures with Various Geometries and Materials | 0 |
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| RF breakdown is one of the major factors determining performance of high power rf components, rf sources and accelerating structures. We study the breakdown in 11 GHz high gradient waveguides at rf powers reaching 300 MW. We tested rectangular waveguides of two geometries which have increased surface electric and magnetic fields in comparison with a standard WR90 waveguide. We used copper, gold, molybdenum, and stainless steel as material for the waveguides. We observe rf parameters, X-rays and visible light from breakdown events. We report the results of the conditioning of these waveguides and compare these results. | ||
| WEPLS115 | Impedances in Slotted-Pipe Kicker Magnets | 2649 |
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| Storage ring slotted-pipe kicker magnets based on the DELTA design are foreseen for the Metrology Light Source (MLS) of the Physikalisch-Technische Bundesanstalt currently under construction near the BESSY site. Although the slotted pipe maintains the cross-section of the storage ring vacuum chamber, image currents have to bypass the slots generating wakefields. Actually modes with substantial impedances have been revealed by simulations and verified by measurements of a kicker model for the MLS. |