  We have observed atmospheric gamma rays from 30GeV to 8TeV, using emulsion
chambers at balloon altitudes, accumulating the largest total exposure in this
energy range to date, SOT ~ 6.66m^2.sr.day. At very high altitudes, with
residual overburden only a few g/cm^2, atmospheric gamma rays are mainly
produced by a single interaction of primary cosmic rays with overlying
atmospheric nuclei. Thus, we can use these gamma rays to study the spectrum of
primary cosmic rays and their products in the atmosphere. From the observed
atmospheric gamma ray spectrum, we deconvolved the primary cosmic-ray proton
spectrum, assuming appropriate hadronic interaction models. Our deconvolved
proton spectrum covers the energy range from 200GeV to 50TeV, which fills a gap
in the currently available primary cosmic-ray proton spectra. We also estimated
the atmospheric muon spectrum above 30GeV at high altitude from our gamma-ray
spectrum, almost without reference to the primary cosmic rays, and compared the
estimated flux with direct muon observations below 10GeV.
