Aerogel Cherenkov counters for high momentum proton identification

Results from ultrarelativistic heavy ion collisions at RHIC indicate that the identification of protons in a large momentum range until 10 or more GeV/c is crucial for the understanding of the underlying processes that govern the production of high momentum baryons in general, and specifically the protons. We have investigated the possibilities to enlarge the present identification of protons from about 5 to 10-12GeV/c using aerogel counters in threshold mode. We present here the simulations for a setup with aerogel cells using one photomultiplier to collect the light emitted and the experimental results for another setup which collects the light via a wavelength shifter foil.