Cosmic-ray intensity at great depths and neutrino experiments

Summary  A group from the Tata Institute of Fundamental Research, Bombay, has recently completed measurements on cosmic-ray intensities deep underground up to depths of 8400 m w.e. On the basis of these observations it is suggested that, for investigations on naturally occuring neutrinos, there are great advantages to be gained by performing the experiments at considerable depths — around 9000 ft. — below the earth‘s surface, essentially because of the very low background which is encountered at such depths. Some features relevant to neutrino physics which emerge from the measurements already made and the design of future experiments to detect cosmic ray produced and extra terrestrial neutrinos are discussed.