Option of aerogel threshold Cherenkov counters for the Super Tau-Charm Facility

A particle identification system (PID) based on the threshold aerogel Cherenkov detectors has been suggested for the Super Tau Charm Facility project. The main aim of the system is to separate pions and kaons in the momentum range from 700 to 2000 MeV/c. For this purpose, the basic option of the Cherenkov threshold counters system is suggested with an aerogel radiator having a refractive index of 1.030. To expand the particle identification capabilities of the detector, an advanced option is suggested with two refractive indices: 1.015 and 1.030. This system could additionally provide \mu/\pi identification in the momentum range from 500 to 900 MeV/c. Both options employ the ASHIPH (aerogel-shifter-photomultiplier) method of Cherenkov light collection. To increase the number of detected photons, the SiPM photodetectors and straight wavelength shifting bars are used in the detectors.