Stress on Cold Mass Due to the Supporting System of the CMS Coil in the Vacuum Tank

This report contains a verification analysis of the stress on cold mass coming from the supporting system of the CMS coil in the vacuum tank. The need to carry out this analysis is related to the high mechanical requirements for $9 Al-alloy mandrels (218 MPa yield at cryogenic temperature), demanding accurate analysis of the impact of supporting system on cylinder stress

Detailed Field Distribution in CMS Winding

The CMS winding has now arrived at its constructive phase. This means that some practical aspects regarding the winding itself have to be considered, such as the minimum requirement of conductor performance for each layer of each $9 module. Several magnetic calculations have been already performed, but the winding has been never analyzed in detail, in order to understand the impact of the self-field on its performances. This analysis and its implications are$9 reported in this paper

Finite Element Model to Study the Deformations of Nb3_{3}Sn Wires for the Next European Dipole (NED)

The Next European Dipole (NED) activity is aimed at the development of a large-aperture, high-field superconducting magnet relying on high-performances Nb$_{3}$Sn conductors. Part of the NED program is devoted to the mechanical study of a new generation of Nb$_{3}$Sn wires and to predict and describe their behavior under the severe loading conditions of the cabling process. The deformation resulting from the cabling process was simulated through mechanical analyses by Finite Elements (FE). The ensuing results of FE analyses are presented, allowing the wire behavior under simple uni-axial loads to be described. They are compared to cross section micrographs of deformed wires

3D Magnetic Analysis of the CMS Magnet

The CMS magnetic system consists of a super-conducting solenoid coil, 12.5 m long and 6 m free bore diameter, and of an iron flux-return yoke, which includes the central barrel, two end-caps and the ferromagnetic parts of the hadronic forward calorimeter. The magnetic flux density in the center of the solenoid is 4 T. To carry out the magnetic analysis of the CMS magnetic system, several 3D models were developed to perform magnetic field and force calculations using the Vector Fields code TOSCA. The analysis includes a study of the general field behavior, the calculation of the forces on the coil generated by small axial, radial displacements and angular tilts, the calculation of the forces on the ferromagnetic parts, the calculation of the fringe field outside the magnetic system, and a study of the field level in the chimneys for the current leads and the cryogenic lines. A procedure to reconstruct the field inside a cylindrical volume starting from the values of the magnetic flux density on the cylinder surface is considered. Special TOSCA-GEANT interface tools have being developed to input the calculated magnetic field into the detector simulation package.Comment: 4 pages, 6 figures, 1 equation, 14 reference

Finite element stress analysis of the CMS magnet coil

The Compact Muon Solenoid (CMS) is one of the experiments which are being designed in the framework of the Large Hadron Collider (LHC) project at CERN. The design field of the CMS magnet is 4 T, the magnetic length is 12.38 m and the aperture is 6.36 m. This is achieved with a 4 layer-5 module superconducting Al-stabilized coil energised at a nominal current of 20 kA. The finite element analysis (FEA) carried out is axisymmetric elasto-plastic. FEA has also been carried out on the suspension system and on the conductor. (8 refs)

Design, construction, and quality tests of the large Al-alloy mandrels for the CMS coil

The Compact Muon Solenoid (CMS) is one of the general-purpose detectors to be provided for the LHC project at CERN. The design field of the CMS superconducting magnet is 4 T, the magnetic length is 12.5 m and the free bore is 6 m. Almost all large indirectly cooled solenoids constructed to date (e.g., Zeus, Aleph, Delphi, Finuda, Babar) comprise Al-alloy mandrels fabricated by welding together plates bent to the correct radius. The external cylinder of CMS will consist of five modules having an inner diameter of 6.8 m, a thickness of 50 mm and an individual length of 2.5 m. It will be manufactured by bending and welding thick plates (75 mm) of the strain hardened aluminum alloy EN AW-5083-H321. The required high geometrical tolerances and mechanical strength (a yield strength of 209 MPa at 4.2 K) impose a critical appraisal of the design, the fabrication techniques, the welding procedures and the quality controls. The thick flanges at both ends of each module will be fabricated as seamless rolled rings, circumferentially welded to the body of the modules. The developed procedures and manufacturing methods will be validated by the construction of a prototype mandrel of full diameter and reduced length (670 mm). (7 refs)

Status of the Super-B factory Design

The SuperB international team continues to optimize the design of an electron-positron collider, which will allow the enhanced study of the origins of flavor physics. The project combines the best features of a linear collider (high single-collision luminosity) and a storage-ring collider (high repetition rate), bringing together all accelerator physics aspects to make a very high luminosity of 10$^{36}$ cm$^{-2}$ sec$^{-1}$. This asymmetric-energy collider with a polarized electron beam will produce hundreds of millions of B-mesons at the $\Upsilon$(4S) resonance. The present design is based on extremely low emittance beams colliding at a large Piwinski angle to allow very low $\beta_y^\star$ without the need for ultra short bunches. Use of crab-waist sextupoles will enhance the luminosity, suppressing dangerous resonances and allowing for a higher beam-beam parameter. The project has flexible beam parameters, improved dynamic aperture, and spin-rotators in the Low Energy Ring for longitudinal polarization of the electron beam at the Interaction Point. Optimized for best colliding-beam performance, the facility may also provide high-brightness photon beams for synchrotron radiation applications