OBSERVATION OF CERENKOV LIGHT FROM EXTENSIVE AIR SHOWER

The pulse shape and the intensity of Cerenkov light from extensive air shower have been recorded by using two different types of photomultipliers (fast and slow). The distribution of the FWHM of Cerenkov light pulse and the spectrum of Cerenkov photo density have been measured for E5×10~(14)eV, at sea level. Comparing the two intensity results from two types of tubes indicate that the system which consists of the slow tubes and the peak ADC is not only simple but also cheap for the Cerenkov light intensity measurement.