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Author Rao Appa, M. V. K.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword PHYSICS ♦ ANGULAR DISTRIBUTION ♦ BALLOONS ♦ COSMIC RADIATION ♦ EARTH ♦ ENERGY RANGE ♦ FISSION ♦ GEOMAGNETIC COORDINATES ♦ HELIUM 3 ♦ HELIUM 4 ♦ HELIUM ISOTOPES ♦ HYDROGEN ♦ INTERACTIONS ♦ LEVELS ♦ MAGNETIC FIELDS ♦ MEASURED VALUES ♦ MOMENTUM ♦ NUCLEAR EMULSIONS ♦ NUCLEI ♦ PARTICLE TRACKS ♦ PRIMARY COSMIC RADIATION ♦ QUANTITY RATIO ♦ RADIATION SOURCES ♦ SCATTERING ♦ SPACE ♦ STARS ♦ STRATOSPHERE
Abstract The isotopic composition of low-energy helium nuclei in the primary cosmic radiation is determined by using the "constant sagitta" scattering method on tracks of helium nuclei stopping in a nuclear-emulsion stack flown at a geomagnetic latitude of 55 deg N and at a mean atmospheric depth of 8.5 g/cm/sup 2/; tracks with zenith angles less than 30 deg are accepted. The ratio of He/ sup 3//(He/sup 3/ + He4) for the same energy per nucleon (between 200 and 400 Mev) is found to be 0.41 plus or minus 0.09 at flight altitude. The correction for production of secondary He/sup 3/ in the residual atmosphere is calculated to be 4%. If one assumes that no He/sup 3/ nuclei are present at the source, the observed ratio corresponds to a traversal of 14 plus or minus 3 g of interstellar matter by the lowenergy helium nuclei. The value of He/sup 3//(He/ sup 3/ + He/sup 4/) corresponding to the same magnetic rigidity (between 1.3 and 1.6 Bv) is found to be 0.36 plus or minus 0.11 which corresponds to a traversal of 12.2 plus or minus 3.5 g of interstellar matter. The observed ratio may indicate the presence of He/sup 3/ at the source of cosmic rays, or may be a reflection of local production within the solar system. (auth)
ISSN 0031899X
Educational Use Research
Learning Resource Type Article
Publisher Date 1961-07-01
Publisher Department Univ. of Rochester, N.Y.
Journal Physical Review
Volume Number 123
Technical Publication No. NYO-9553
Organization Univ. of Rochester, N.Y.


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