Direct measurement of the composition and spectra of cosmic rays above 1 TeV/amu from Jacee
Direct measurements on cosmic ray protons through iron above about 1 TeV/amu have been performed in a series of balloon-borne experiments with emulsion chambers. The measured energy spectra of protons and helium are power laws with exponents of 2.77 ± 0.09 and 2.72 ± 0.11 in the energy range 5 to 500 TeV and 2 to 50 TeV/amu, respectively. The proton spectrum shows no evidence of the steepening near 2 TeV which was reported by other experiments. Helium has a slightly higher intensity compared to extrapolations from lower energy measurements. The heavier elements, carbon to sulfur, show a small tendency for intensity enhancement in the relative abundance above 10 TeV/amu. © 1989.
Publication Source (Journal or Book title)
Advances in Space Research
Parnell, T., Burnett, T., Dake, S., Derrickson, J., Fountain, W., Fuki, M., Gregory, J., Hayashi, T., Holynski, R., Iwai, J., Jones, W., Jurak, A., Lord, J., Miyamura, O., Oda, H., Ogata, T., Roberts, F., Strausz, S., Tabuki, T., Takahashi, Y., Tominaga, T., Watts, J., Wefel, J., Wilczynska, B., Wilczynski, H., Wilkes, R., Wolter, W., & Wosiek, B. (1989). Direct measurement of the composition and spectra of cosmic rays above 1 TeV/amu from Jacee. Advances in Space Research, 9 (12), 45-54. https://doi.org/10.1016/0273-1177(89)90307-4