NEUTRON HIGH-ENERGY SPECTRA AT 5 MBAR NEAR GEOMAGNETIC EQUATOR

Ilford G//5 emulsions were exposed at 4 and 6 mbar on balloon flights from Hyderabad, India, at lambda equals 7. 8 degree N. Atmospheric neutrons in the energy range from about 8 to 200 MeV are studied. Two independent parameters are used: knock-on protons covering the neutron energy range 8 to 160 MeV and low-energy evaporation stars for approximately 40 to 200 MeV. Neutron fluxes and up/down ratios near 5 mbar are given for different energy ranges. A power law of the form AE** minus **n is fitted to the experimental data, and values of the spectral index n are given. These results are compared with theoretical and experimental results reported by other workers.