Statistical analysis of SAMPEX PET proton measurements

We present a statistical study of the distributions of proton counts from the Proton–Electron Telescope aboard the low-altitude polar satellite SAMPEX. Our statistical analysis shows that histograms of observed proton counts are generally distributed according to Poisson distributions but are sometimes quite different. The observed departures from Poisson distributions can be attributed to variations of the average flux or to the non-constancy of the detector lifetimes.