Speaker
Description
Saturated fluorocarbons (CnF(2n+2)) are chosen for their optical properties as Cherenkov radiators, with C4F10 and CF4 used in COMPASS and LHCb RICH1&2. Non-conductivity, non-flammability and radiation resistance make them ideal coolants with C6F14 used in all LHC experiments, while C3F8 evaporatively cools the ATLAS silicon tracker. These fluids however have high GWPs (>5000*CO2).
While not yet industrialised over the full CnF2nO range fluoro-ketones can offer similar performance at very low, or 0 GWP. The radiation tolerance and thermal performance of 3M NOVEC 649 (C6F12O) is sufficiently promising to be chosen by CERN to replace C6F14. Subject to optical testing, NOVEC 5110 (C5F10O) - blended with N2 and monitored in real time by sound velocity gas analysis - could replace C4F10 and CF4 in RICH detectors. Lighter molecules (e.g. C2F4O, with similar thermodynamics to C2F6) - would allow lower temperature, 0GWP operation than evaporative CO2 in Si trackers operated at high luminosity.
| Alternate track | 13. Detectors for Future Facilities, R&D, Novel Techniques |
|---|---|
| I read the instructions above | Yes |
