Quenching the scintillation in CF4 Cherenkov gas radiator

Abstract

a b s t r a c t CF 4 is used as a Cherenkov gas radiator in one of the Ring Imaging Cherenkov detectors at the LHCb experiment at the CERN Large Hadron Collider. CF 4 is well known to have a high scintillation photon yield in the near and far VUV, UV and in the visible wavelength range. A large flux of scintillation photons in our photon detection acceptance between 200 and 800 nm could compromise the particle identification efficiency. We will show that this scintillation photon emission system can be effectively quenched, consistent with radiationless transitions, with no significant impact on the photons resulting from Cherenkov radiation.

The LHCb Upgrade I

“…The simulation used to obtain the results presented in this section includes the up to date information on the RICH geometry and on the properties of its optical system and photon detection chain. The properties of the individual photon detector channels, such as the MaPMT gain and noise, are accounted for; in addition, background sources such as cross-talk, afterpulses and scintillation photons produced by charged particles in the CF 4 radiator are included as well [123]. In the simulation, the values related to the mentioned aspects of the individual channels are based on the data acquired during quality assurance procedures with a 900 V bias voltage for the MaPMTs.…”