The Future Circular Collider (FCC) study includes the design of the detector magnets for the FCC-ee+ (electron-positron) collider, requiring a 2 T solenoid for particle spectrometry, and for the FCC-hh (proton-proton) collider, with a 4 T detector solenoid. For both solenoids and their cryostats, CERN is developing an innovative and challenging design in which the solenoids are positioned inside the calorimeters, directly surrounding the inner tracker. For this purpose, the cryostats must be optimized to have maximum radiation transparency. They are structured as a sandwich of thinnest possible metallic shells for achieving vacuum tightness, supported by layers of low density and highly radiation transparent insulation material, still providing sufficient mechanical resistance and low thermal conductivity. In this respect, thermal and mechanical analysis of innovative insulation materials are currently being carried out. The first material of interest, Cryogel® Z, is shaped as a flexible composite blanket, which combines silica aerogel with reinforcing fibers and a density of 160 kg/m3. It allows a 4 m bore, 6 m long FCC-ee+ detector solenoid cryostat with a total thickness of 250 mm. CERN has investigated the compression of Cryogel® Z under 1 bar equivalent mechanical load and its thermal conductivity between 10 K and room temperature, as well as the critical phenomena of thermal shrinkage and outgassing. We present the test results, as a first overview on the material.
|Journal||IOP Conference Series: Materials Science and Engineering|
|Publication status||Published - 29 Jun 2020|
|Event||2019 Cryogenic Engineering Conference and International Cryogenic Materials Conference, CEC/ICMC 2019 - Connecticut Convention Center, Hartford, United States|
Duration: 21 Jul 2019 → 25 Jul 2019