Study of extensive air showers at sea level using a flash tube chamber

The density spectrum of extensive air shower; particles was measured using a proportional counter. It was found that the slope of the integral spectrum changes from -1.5 to -2.0 at about 1,000 m(^-2). Using this spectrum the primary energy spectrum of cosmic rays was derived. In measuring the density spectrum of extensive air showers, the selection system consists of three large liquid scintillators placed horizontally on the roof of a large volume flash tube chamber. In each trigger the passage of the penetrating component through the chamber were photographed. The density spectrum of the penetrating component of extensive air showers was measured and the results compared with the expected spectrum folding the derived number spectrum, measuring the density spectrum of extensive air showers, into the lateral distribution of muons. The energy spectra of charged and neutral hadrons in extensive air showers of median shower size of 2.7.10(^5) particles have been measured. The results have been related to the energy spectra of hadrons in shower range of 2.10(^4) to 4.10(^5) particles. A search for charged (^e)/3 particles (quarks) close to the core of extensive air showers, of median size of 2.7.10(^5) particles, has been carried out. In 5,420 hrs running time no quark candidate has been observed. The upper limit on the quark flux being 5.5.10(^-11) cm(^-2)s(^-1)st(^-1) at 90% confidence level