A High Speed Chronograph and its Application to the Time of Flight of Cosmic Rays

Abstract

A high speed chronograph using a 20 turn spiral time base of 1 μsec. duration per turn 1s described, together with its video amplifiers, delay lines, radial deflection circuits, and recording equipment. The time of flight of cosmic ray mesons over a range of 5.45 m. has been detected using ordinary Geiger counters. and found to agree with the velocity of light within the accuracy of the experiment. A time lag of 2 x 10^-8 sec. between the firing of a tray of counters shielded with 10 cm. of lead and the firing of a similar unshielded tray by extensive air showers has been accounted for. and the results shown to be consistent with the theoretical expectation that most of the shower particles arrive at the trays within a time <10^-9 sec.