2000/05/04 by J. Poirier, Poirier, J., J. Carpenter +9
Medicine · Physics and Astronomy · #Astrophysics (astro-ph) #Astrophysics and Cosmic Phenomena #Dark Matter and Cosmic Phenomena #FOS: Physical sciences #Radiation Therapy and Dosimetry #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/0005089
4 pages including 1 table and 4 figures. OG.3.1.12 in 26th ICRC, 4, 172 (1999)
arxiv created 2000/05/04 · openalex publication_date 2000/05/04 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Project GRAND presents results on the atomic composition of primary cosmic rays. This is accomplished by determining the average height of primary particles that cause extensive air showers detected by Project GRAND. Particles with a larger cross sectional area, such as iron nuclei, are likely to start an extensive air shower higher in the atmosphere whereas protons, with a smaller cross section, would pass through more air before interacting and thus start showers at lower heights. Such heights can be determined by extrapolating identified muon tracks backward (upward) to determine their height of origin (Gress et al., 1997). Since muons are from the top, hadronic part of the shower, they are a good estimator for the beginning of the shower. The data for this study were taken during the previous year with 20 million shower events.