Chorowski, M Grzegory, P Parente, C Riddone, G Optimisation of Multilayer Insulation: an Engineering Approach A mathematical model has been developed to describe the heat flux through multilayer insulation (MLI). The total heat flux between the layers is the result of three distinct heat transfer modes: radiation, residual gas conduction and solid spacer conduction. The model describes the MLI behaviour considering a layer-to-layer approach and is based on an electrical analogy, in which the three heat transfer modes are treated as parallel thermal impedances. The values of each of the transfer mode vary from layer to layer, although the total heat flux remains constant across the whole MLI blanket. The model enables the optimisation of the insulation with regard to different MLI parameters, such as residual gas pressure, number of layers and boundary temperatures. The model has been tested with experimental measurements carried out at CERN and the results revealed to be in a good agreement, especially for insulation vacuum between 10-5 Pa and 10-3 Pa. eng 2001

http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=lhc-project-report-464; http://cds.cern.ch/record/486721/files/lhc-project-report-464.pdf; http://cds.cern.ch/record/486721/files/lhc-project-report-464.ps.gz;

Imported from Invenio. Bremer, J Delikaris, D Delruelle, N Haug, F Passardi, Giorgio Perinic, G Cryogenics for the Large Hadron Collider Experiments High Energy Physics experiments have frequently adopted cryogenic versions of their apparatus to achieve the desired performance. Among the four new experiments for the CERN Large Hadron Collider (LHC) the two largest, ATLAS and CMS, include spectrometers using 4.5 K superconducting magnets and detectors filled with liquid argon at 87 K, respectively for particle momentum and energy measurements. These detectors are of unprecedented size and complexity and the definition of the associated cryogenic systems is the result of a collaboration between CERN and several external institutes all around the world. A review of the various systems is presented with particular emphasis to the basic cooling principles, the special cryogenic features and the operation scenarios. eng 2000

http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=lhc-project-report-458; http://cds.cern.ch/record/483801/files/lhc-project-report-458.pdf; http://cds.cern.ch/record/483801/files/lhc-project-report-458.ps.gz;

Imported from Invenio. Benda, V Bozzini, D Riddone, G Vandoni, Giovanna Measurement on Different MLI Systems Between 77 K and 4 K and their Application in Cryogenic Engineering Precise thermal measurements were done on different types of large surface MLI samples under various boundary conditions. The measurements were focused on the use of MLI for large industrial plants considering quick and simple installation. The results of the measurements aim at optimising MLI parameters, which control the thermal behaviour. Practical recommendations of MLI materials and their installation are given. eng 2000

http://documents.cern.ch/cgi-bin/setlink?base=preprint&categ=cern&id=lhc-project-report-457; http://cds.cern.ch/record/483800/files/lhc-project-report-457.pdf; http://cds.cern.ch/record/483800/files/lhc-project-report-457.ps.gz;

Imported from Invenio.