doi:10.1016/S0011-2275(01)00016-9engChorowski, MGrzegory, PSerio, LVan Weelderen, RModelling of Helium-mediated Quench Propagation in the LHC Prototype Test String-1Accelerators and Storage RingsLHC-Project-Report-468CERN-LHC-Project-Report-468The Large Hadron Collider (LHC) prototype test string-1, hereafter referred to as the string, is composed of three ten-meter long prototype dipole magnets and one six-meter long prototype quadrupole magnet. The magnets are immersed in a pressurized static bath of superfluid helium that is maintained at a pressure of about 1 bar and at a temperature of about 1.9 K. This helium bath constitutes one single hydraulic unit, extending along the 42.5 m of the string length. We have measured the triggering of quenches of the string magnets due to the quenching of a single dipole magnet located at the string's extremity; i.e. "quench propagation". Previously reported measurements enabled to establish that in this configuration the quench propagation is mediated by the helium and not by the inter-magnet busbar connections [1], [2]. We present a model of helium mediated quench propagation based on the qualitative conclusions of these two previous papers, and on additional information gained from a dedicated series of quench propagation measurements that were not previously reported. We will discuss the specific mechanisms and their main parameters involved at different time scales of the propagation process, and apply the model to make quantitative predictions.2001-03-23http://cds.cern.ch/record/49332410.1016/S0011-2275(01)00016-9http://cds.cern.ch/record/493324oai:cds.cern.ch:493324 doi:10.1016/S0011-2275(01)00015-7engSanfilippo, SSiemko, AMethods for the Evaluation of Quench Temperature Profiles and their Application for LHC Superconducting Short Dipole MagnetsAccelerators and Storage RingsLHC-Project-Report-459CERN-LHC-Project-Report-459This paper presents a study of the thermal effects on quench performance for several Large Hadron Collider single aperture short dipole models. The analysis is based on the temperature profile in a superconducting magnet evaluated after a quench. Peak temperatures and temperature gradients in the magnet coil are estimated for different thicknesses of insulation layer between the quench heaters and the coil and different powering and protection parameters. The results show clear correlation between the thermo-mechanical response of the magnet and quench performance. They also display that the optimisation of the position of quench heaters can reduce the decrease of training performance caused by the coexistence of a mechanical weak region and of a local temperature rise.2001-01-19http://cds.cern.ch/record/48393910.1016/S0011-2275(01)00015-7http://cds.cern.ch/record/483939oai:cds.cern.ch:483939 doi:10.1016/S0011-2275(01)00019-4engBottura, LBreschi, MRosso, CA General Model for Thermal, Hydraulic and Electric Analysis of Superconducting CablesAccelerators and Storage RingsLHC-Project-Report-456CERN-LHC-Project-Report-456In this paper we describe a generic, multi-component and multi-channel model for the analysis of superconducting cables. The aim of the model is to treat in a general and consistent manner simultaneous thermal, electric and hydraulic transients in cables. The model is devised for most general situations, but reduces in limiting cases to most common approximations without loss of efficiency. We discuss here the governing equations, and we write them in a matrix form that is well adapted to numerical treatment. We finally demonstrate the model capability by comparison with published experimental data on current distribution in a two-strand cable.2000-12-22http://cds.cern.ch/record/48349410.1016/S0011-2275(01)00019-4http://cds.cern.ch/record/483494oai:cds.cern.ch:483494