9318909 Yodh Support for research is granted to faculty at the University of California at Irvine to study characteristics of high energy cosmic rays, especially gamma rays and neutrinos, incident on earth. The goal is to establish the identity of as yet unknown sources and explicate still unknown acceleration mechanism(s). Those are subjects of intense current interest and activity. One major thrust is the development of MILAGRO, a new air-shower detector that makes use of Cerenkov radiation produced by shower parties in a large pool of water. The other is continued deployment and operation of neutrino and muon detectors, the AMANDA array, in the ice at Antarctica that serves as an extended Cerenkov radiator. ***