| Paper | Title | Page |
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| WEPD003 | Manufacture and Test of a Small Ceramic-insulated Nb3Sn Split Solenoid | 2404 |
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A small split solenoid wound with high Jc Nb3Sn conductor, constituted by a 0.8 mm Rod Re-stack Process (RRP) strand, was built and tested at CERN in order to study the applicability of:
*B. Bordini, E. Barzi, S. Feher, L. Rossi, and A. V. Zlobin. "Self-Field Effects in Magneto-Thermal Instabilities for Nb-Sn Strands," to be published in IEEE Trans. Appl. Supercond. 2008. |
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| WEPD025 | A Feasibility Study of Superconducting Dipole for the Early Separation Scheme of SLHC | 2461 |
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| In the framework of the LHC luminosity upgrade an early separation scheme is being studied for the final phase (L~1035 cm-2 s-1 with substantial changes in the IR). In this paper we compare a Nb3Sn and a Nb-Ti cos(θ) design: the aim is to explore the benefits and the limits of a compact solution with respect to the detector's constraints and the energy deposition issues. We propose to put the dipole system (cryostat and magnet) at a location starting at 6.8 m from the IP. The preliminary cross section, the achievable integrated field, the energy deposition on the magnet are presented and discussed. | ||
| WEPD027 | A new cable insulation scheme improving heat transfer in Nb-Ti superconducting accelerator magnets | 2467 |
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The next applications of superconducting magnets for interaction regions of particle colliders or for fast cycled accelerators require dealing with large heat fluxes generated or deposited in the coils. Last year* we have anticipated the theoretical potential for a large improvement of heat transfer of state of the art Nb-Ti cable insulations in superfluid helium, such as the one used for the LHC superconducting magnets. In this paper we present and discuss new experimental results, confirming that a factor of 5 increase of the allowed heat flux from coil to coolant can be obtained with the new insulation topology while keeping a sound margin in the dielectric performance.
*M. La China, D. Tommasini. “Cable Insulation Scheme to Improve Heat Transfer to Superfluid Helium in Nb-Ti Accelerator Magnets,” MT-20, Philadelphia, USA, August 2007. |
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| WEPD001 | The Quality Control of the LHC Continuous Cryostat Interconnections | 2398 |
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| The interconnections between the Large Hadron Collider (LHC) magnets have required some 40 000 TIG welded joints and 65 000 electrical splices. At the level of single joints and splices, non-destructive techniques find limited application: quality control is based on the qualification of the process and of operators, on the recording of production parameters, and on production samples. Visual inspection and process audits were the main techniques used. At the level of an extended chain of joints and splices - from a 53.5 m half-cell to a complete 2.7 km sector - quality control is based on vacuum leak tests, electrical tests and RF microwave reflectometry that progressively validated the work performed. Subsequent sector pressure tests, cryogenic circuits flushing with high pressure helium and cool-downs revealed a few unseen or new defects. The nature of defects is analyzed and classified according to their origin. Methods for defect localization are described. This paper presents an overview of the quality control techniques used and critically evaluates their effectiveness in progressively identifying defects, seeking lessons applicable to similar large, complex projects. | ||
| WEPD006 | Conceptual Design of Superferric Magnets for PS2 | 2410 |
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| We analyze feasibility and cost of a superferric magnet design for the PS2, the novel 50 GeV ring that should replace the PS in the CERN injector chain. Specifically, we provide the conceptual design of dipole and quadrupoles, including considerations on cryogenics and powering. The magnets have warm iron yoke, and cryostated superconducting coils embedded in the magnet, which reduces AC loss at cryogenic temperature. The superconductor has large operating margin to endure beam loss and operating loads over a long period of time. Although conservative, and without any critical dependence on novel technology developments, this superconducting option appears to be attractive as a low-power alternative to the normal-conducting magnets that are the present baseline for the PS2 design. In addition it provides flexibility in the selection of flat-top duration at no additional cost. | ||
| WEPD012 | The LHC Continuous Cryostat Interconnections: the Organization of a Logistically Complex Worksite Requiring Strict Quality Standards and High Output | 2428 |
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| The interconnections of the Large Hadron Collider (LHC) continuous cryostat have been completed in autumn 2007: 1695 magnet to magnet interconnections and 224 interconnections between the continuous cryostat and the cryogenic distribution line have been closed along the 27km of the LHC. The high productivity demanded, the complexity of the interconnection sequence, the strict quality standards have required an ad hoc organization in order to steer and coordinate the activities on a worksite that was spread along the whole accelerator ring. The optimization of the intricate sequence of construction and test phases carried out by CERN staff, CERN collaborating institutes and contractors have led to the necessity of a common approach and of a very effective information flow. Specialized CERN teams have been created to deal with non standard operation to smooth the work sequences of the main assembly teams. In this paper, after having recalled the main technical challenges, we review the organizational choices that have been taken, their impact on quality and productivity and we briefly analyze the development of the worksite in term of allocated resources and production. |