Test of aerogel as Cherenkov radiator

Two dierent stacks of aerogel were tested on a pion/proton beam of momentum between 3 and 10 GeV/c. The optical characteristics of the tested aerogel samples were dierent: in particular one sample was hygroscopic while the other was hydrophobic. Two HPD tubes were used as photodetectors, and dierent thickness of the stacks were tried, in order to determine the photoelectron yield, the Cherenkov angle and its resolution. =p separation has been proved up to momenta of 10 GeV/c.