RELATIVE ABUNDANCES OF THE HEAVY NUCLEI OF THE GALACTIC COSMIC RADIATION

Journal Article · Mon Jan 01 04:00:00 EST 1962 · J. Phys. Soc. Japan

OSTI ID:4764117

O'Dell, F W; Shapiro, M M; Stiller, B

For a decade, controversy has persisted over the question: does the galactic cosmic radiation incident upon the top of the atmosphere contain a significant fraction of Li, Be, and B? This question has an important bearing on the age'' of the cosmic radiation and on its propagation through interstellar space. To resolve the problem, an emulsion experiment was designed to provide (a) higher statistical weight, (b) exposure at greater altitude, and (c) verifiable charge identification by employing several independent methods of ionization measurement in emulsions of different sensitivities. The balloon, launched at geomagnetic latitude 41 deg N, on March 9, 1958, floated at an atmospheric depth of 2.7 g/cm/sup 2/ for 71/2 hours. Over 900 tracks were analyzed, and the L tracks (due to Li, Be, and B) were well resolved from the heavier (S) tracks. The ratio (L/S)/sub 0/ at the top of the atmosphere was found to be 0.l8 plus or minus 0.04, and (H/M)/sub 0/ = 0.38 plus or minus 0.04. The value 0.14 is considered a lower limit for (L/S)/sub 0/ since it was obtained by using the extremely large Rochester fragmentation coefficients P/sub HL/ and P/sub ML/ in extrapolating to the top of the atmosphere. The results demonstrate conclusively that Li, Be, and B comprise a significant proportion of the heavy primary nuclei, and that their relative cosmic-ray abundance is appioximately 2 x 10/sup 5/ times their relative universal'' abundance. Relative to carbon or oxygen, cosmic-ray nitrogen was found to be about one-half as abundant as previously supposed. (auth)

• Research Organization: Naval Research Lab., Washington, D.C.
• NSA Number: NSA-17-013010
• OSTI ID: 4764117
• Journal Information: J. Phys. Soc. Japan, Journal Name: J. Phys. Soc. Japan Vol. Vol: 17: Suppl. A-III
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ATMOSPHERE
ATOMS
BALLOONS
BERYLLIUM
BORON
CARBON
COSMIC RADIATION
ELECTRIC CHARGES
IONIZATION
LITHIUM
MEASURED VALUES
MOTION
NITROGEN
NUCLEAR EMULSIONS
NUCLEI
OXYGEN
PARTICLE TRACKS
PHYSICS
QUANTITY RATIO
RESOLUTION
SENSITIVITY
SPACE
STATISTICS