| Paper | Title | Page |
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| MOPPC002 | Local Chromatic Correction Scheme and Crab-waist Collisions for an Ultra-low β* at the LHC | 118 |
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Funding: Work supported by the European Commission under the FP7 Research Infrastructures project Eu- CARD, grant agreement no. 227579. We discuss potential merits and the parameter range of interest for a possible crab-waist collision scheme at the LHC, and report preliminary optics studies of a local chromatic correction scheme with flat beams (βx*>>βy*), which could boost the LHC luminosity by about an order of magnitude and would also allow for crab-waist collisions. |
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| TUPPR061 | First Magnetic Test of a Superconducting Nb3Sn Wiggler Magnet for CLIC | 1957 |
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| In the Compact Linear Collider (CLIC) the normalized horizontal and vertical emittances of the electron and positron beams must be reduced to 500 nm and 5 nm before the beams enter the 3 TeV linear accelerators. An effective way to accomplish ultra-low emittances are damping rings. Damping rings are storage rings equipped with strong wiggler magnets. In a first approximation damping wigglers are more effective the shorter the period length and the stronger the magnetic field is. Only superconducting wiggler magnets meet the demanding magnetic specifications of the CLIC damping rings. Nb-Ti damping wiggler magnets fulfill the specifications of CLIC but Nb3Sn wiggler magnets would reach higher magnetic fields leading to even better beam properties for CLIC. Moreover, they have at the same time higher thermal and magnetic margins. Therefore, Nb3Sn wiggler magnets are under investigation at CERN despite the challenging manufacturing process. This paper presents first results of Nb3Sn coils and short model tests and outlines the further plans for developing Nb3Sn wiggler magnets at CERN. | ||
| TUPPR075 | Challenges for the Magnet System of LHeC | 1996 |
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| The main challenges for the normal conducting magnet system are the very compact, low field, and high precision magnets for the ring-ring option and their rapid installation in the crowded LHC tunnel. The superconducting triplet magnets require strong gradients for the protons in close vicinity of a field-free region for the electrons. The field requirements for the ring-ring option allow a number of different magnet designs using the well-proven Nb-Ti superconductor technology and making use of the cable development for the LHC. The separation distance between the electron and proton beams in Q1 requires a half-aperture quadrupole design to limit the overall synchrotron radiation power emitted by the bending of the electron beam. The requirements in terms of aperture and field gradient are more difficult to obtain for the Linac-Ring option. Consequently we present the limitations for the field gradient and septum size achievable with both Nb-Ti and Nb3Sn superconducting technologies. | ||
| TUPPC086 | Conceptual Design of the CLIC damping rings | 1368 |
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| The CLIC damping rings are designed to produce unprecedentedly low-emittances of 500 nm and 5 nm normalized at 2.86 GeV, in all beam dimensions with high bunch charge, necessary for the performance of the collider. The large beam brightness triggers a number of beam dynamics and technical challenges. Ring parameters such as energy, circumference, lattice, momentum compaction, bending and super-conducting wiggler fields are carefully chosen in order to provide the target emittances under the influence of intrabeam scattering but also reduce the impact of collective effects such as space-charge and coherent synchrotron radiation. Mitigation techniques for two stream instabilities have been identified and tested. The low vertical emittance is achieved by modern orbit and coupling correction techniques. Design considerations and plans for technical system, such as damping wigglers, transfer systems, vacuum, RF cavities, instrumentation and feedback are finally reviewed. | ||
| THPPD030 | Characterization of a Measurement System for Dynamic Effects in Large-aperture SC Quadrupole Magnets | 3569 |
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A new measurement system, based on a large-diameter search-coil rotating in the superfluid helium, a fast digital integrator, a motor drive unit with sliprings, and a flexible software environment was devolped at CERN for the measurement of dynamic effects in superconducting magnets*. This system has made it possible the measure, with a resolution of up to 8 Hz, the multipole field errors due to superconductor magnetization and interstrand coupling currents. In the paper we will present the development and calibration of the measurement system, its installation in the vertical cryostat of CERN's recently refurbished test station, and its application to the US-LARP** built, 120-mm-aperture Nb3Sn quadrupole magnet (HQ) for the upgrade of the LHC insertion regions.
* P. Arpaia et al. Active Comp. of Field Errors within ± 2 PPM in SC Magnets, NIM A, 2011 ** H. Felice et al. Design of HQ, a High Field Large Bore Nb3Sn Quad. Magnet for LARP, IEEE TAS, 2009 |
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