LXXXV. Cosmic rays at60 m.w.e.Underground II: The hard and soft components

Abstract

Abstract The tracks of the relativistic charged particles, which have been found and examined by the methods described in I, are used to estimate the total vertical intensity and the electron component at 60 m.w.e. The total vertical intensity is found to be (6·8±1)10-4 particles/cm2/sec/steradian. About 0·5% of the relativistic charged particles with momenta greater than 100 mev/c are electrons. The possible sources of these electrons are examined and it is found that they consist almost entirely of knock-on electrons and. their cascade progeny. Both the absolute rate and the spectrum of the electron pairs which are found on the plates indicate an electron component whose magnitude is rather greater than can be accounted for by known sources. A detailed analysis is also made of 20 tridents and it is shown that they consist of 9 electron and 11 μ-meson tridents. The μ-meson tridents are classified further into the various cases covered by Bhabha's theory. I t is again found that, rather more electron trid...