A study of particles close to the core of extensive air showers using a flash tube chamber

Abstract

A search for particles carrying an electric charge one third that of the electronic charge (quarks) has been carried out close to the core of extensive air showers. The search was conducted at sea-level using a large volume flash tube chamber. The technique employed utilised these nativity of flash tubes to particle ionisation. Air showers were selected by requiring the local electron density above the detector to exceed 40 m (^-40) with this trigger the apparatus has been operated for 2570 hours. No definite quark tracks have been observed, the upper limit on the quark flux being set at 8.0 x 10 (^-11) cm (^-2) sec (^-1) st (^-1). In the same experiment, the energy spectra of charged and neutral nuclear-active particles in extensive air showers of mean shower size 2.0 x `0 (^5) has been measured. A method has been developed for estimating the energies of the particles from the width of the nuclear-electromagnetic cascade resulting from the interactions, as measured in flash tubes below the absorbers. The results have been related to extensive air shower characteristics; in particular to the nuclear-physical aspects of very high energy collisions. The flash tube chamber has been modified to allow the relationship between the width of the nuclear-electromagnetic cascade and the energy of the interacting particle to be established. The experiment, utilising the flux of unaccompanied hadrons in the near-vertical direction, has also allowed the energy spectrum of these particles to be determined up to energies of ITeV.