Measuring the Spectrum of Ultrahigh Energy Cosmic Rays using the Monte Carlo Technique

The technique for measuring the spectrum of the highest energy cosmic rays using the air-fluorescence technique has been well-developed over the last few decades. Due to the complexity of the phenomena that occur during an extensive air shower (the production of fluorescence and Cerenkov light including scattering and attenuation), correctly determining the energy-dependence of the aperture requires the creation of a good full-detector Monte Carlo which accurately reproduces measurable quantities of the air shower. The Telescope Array Monte Carlo simulation will be explained and plots comparing data and Monte Carlo will be shown.