VHMPID detector for the ALICE experiment upgrade at LHC

Results from high energy nucleus-nucleus collisions at RHIC have shown the importance of particle identification in a very large momentum range, in particular for protons. The ALICE experiment has unique capabilities to identify particles, however its momentum coverage for track-by-track identification should be extended to meet new physics challenges at LHC. The Very High Momentum Charged Particle Identification (VHMPID) detector represents a possible upgrade of the ALICE experimental apparatus. It has been conceived to extend proton identification on a track-by-track basis up to p=30GeV/c. The VHMPID is a Ring Imaging Cherenkov with C_4F_1_0 gaseous radiator coupled to a CsI based photon detector. The focusing properties of a spherical mirror ar e exploited to focus Cherenkov photons on the photon detector. The detector layout and the expected performance will be discussed. First results from beam tests of a prototype of 60x40cm^2 will be also presented.