Cosmic Ray Flux Measurements Versus Altitude

We have investigated the structure of cosmic ray showers with altitude. In order to do this we have measured the omnidirectional cosmic ray count, the vertical coincidence cosmic ray flux, and the horizontal coincidence flux during a balloon flight. All the measurements reach a maximum near the same altitude, the Pfotzer maximum. The Pfotzer maximum has generally been interpreted as the altitude at which the maximum number of ionizing particles are detected. More flights will be carried out to confirm these results or detect differences among the maxima and examine the effects of atmospheric conditions on the cosmic ray shower structure. The goal is to develop a mathematical description of the cosmic ray shower structure and Pfotzer maximum as a function of altitude and other atmospheric conditions. We are also working on a more efficient design to carry out the measurements