Focusing aerogel RICH (FARICH)

In this work we investigate a Ring Imaging Cherenkov detector based on “focusing” aerogel (FARICH). In the proximity focusing RICH, one of the main factors determining precision of ring radius measurements is a finite thickness of a radiator. FARICH development aims at the reduction of this effect by means of using multilayer aerogel. Two options have been considered. ring: refraction index and thickness of each layer are adjusted in such a way that Cherenkov rings from different layers are superimposed on each other. ring: refraction index and thickness of each layer are adjusted so that ring images from different layers have different radii and are clearly separated from each other. e first time in the world we have developed a technique for production of multilayer aerogels (SAN-MULTI). A few samples consisting of four aerogel layers with indices from 1.022 to 1.030 have been produced. T4 based simulation program has been developed. Velocity resolution was investigated for different momenta and particle incidence angles. It was shown that velocity resolution of 5 × 10 - 4 is achievable. This permits us to have π / K separation at the level of more than 3 σ up to momentum 8.0 GeV / c , π / μ separation up to momentum 1.6 GeV / c .