THE RELATIVE ABUNDANCES OF COSMIC RAY NUCLEI OF CHARGE

A stack of 72 IIford G5 stripped emulsions, 12 in. x 9 in. x 600 mu m, was flown from Brownwood, Texas (geomagnetic latitude, 41 deg N), on March 9, 1958, for 7.5 hr at a ceiling height of 136,000 ft. The total amount of matter above the emulsion was 3.2 g/cm/sup 2/. All the emulsions were scanned along a line 5 nan below the top edge for tracks with grain densities at least six times that at minimum ionization. A comparison was made of charge determination by gamma-ray density and gap density measurements. The value 0.20 plus or minus 0.02 was obtained for the relative abundance of light nuclei in cosmic radiation. (M.C.G.)