Search

It is shown that ultrasonic phased-array technology can be used to control the bond quality of the Compact Muon Solenoid (CMS) conductor. The CMS is a general-purpose detector for CERN's Large Hadron Collider (LHC).

The structure of the superconducting coil of the Continuous Muon Solenoid (CMS) is discussed. The CMS is a general-purpose detector that will be used for the Large Hadron Collider (LHC) project at CERN.

The Compact Muon Solenoid (CMS) is a general-purpose particle detector to be used with the Large Hadron Collider (LHC) at CERN. The main features of the CMS conductor are discussed.

The aluminum stabilizer for the Compact Muon Solenoid conductor was studied to determine residual resistivity ratio variations under dynamic stress at 4.2 K.

The Compact Muon Solenoid experiments for the Large Hadron Collider project at CERN are described with a focus on the high magnetic field.

The R&D stages and results from first production of the conductor for the superconducting toroids of the ATLAS experiment are described.

For high performance superconducting magnets as used in large detectors for the High Energy Physics or for magnets of magnetic storage devices (SMES) the mechanical stresses on the conductor go beyond the yield stress level of the high purity matrix stabiliser, specially if aluminium is used. Therefore, a novel method is proposed to join high strength aluminium strips to high purity aluminium stabiliser by using the electron beam (EB) welding. The proposed EB - welding, combined with roll-pressing under vacuum, provides the minimum heat input on the conductor in comparison with other welding techniques. This method provides the advantage to allow the production of very long conductor lengths and includes the potentiality of repairing without losing expensive material. As this process has to be adapted to the high purity aluminium on the one side and to the high strength material on the other, we started in a first step with investigation and development of the process, using standard laboratory machines together with laboratory - size tooling. In this report the development programme is described and first results o f the quality control measurements are presented.

Studies electron-hole interaction in thulium selenide[sub1-x]tellurium[subx] at low temperatures. Coexistence of intermediate valency and magnetic order; Significance of the thermal excitation of electrons from the localized level; Change from a continuous semiconductor-to-metal transition (SMT) at high temperatures to a discontinuous SMT at lower temperature.

CMS (Compact Muon Solenoid) is a general-purpose detector designed to run at the highest luminosity at the CERN Large Hadron Collider (LHC). Its distinctive features include a 4 T superconducting solenoid with 6 m diameter by 12.5 m long free bore, enclosed inside a 10,000-ton return yoke. Its magnet coil is wound from a pure aluminum stabilized superconductor. In order to withstand the considerable magnetic forces the conductor is reinforced by attaching high-strength aluminum alloy profiles using an Electron Beam (EB) welding process. 20 unit lengths of conductor, 2.5 km each, are needed. Only a complete bonding ensures the required mechanical strength of the conductor. The quality control of the welding is a key element in the success of the fabrication. Hence, we have introduced into the production line, just after the EB welding unit, a specifically developed ultrasonic imaging system. A highs Peed phased-array instrument copes with the challenge of a continuous monitoring of the welding quality over the whole width and the complete length of the conductor. The performance of the ultrasonic inspection system and the assessment of ultrasonic indications with respect to different types of welding flaws is shown. By now over 45 km of the CMS conductor have been successfully welded and inspected. [ABSTRACT FROM AUTHOR]