EXPERIMENTS ON THE ELEVEN-YEAR CHANGES OF COSMIC-RAY INTENSITY USING A SPACE PROBE

Journal Article · Thu Sep 15 04:00:00 EDT 1960 · Phys. Rev. Letters

DOI:https://doi.org/10.1103/PhysRevLett.5.272· OSTI ID:4133900

Fan, C Y; Meyer, P; Simpson, J A

Experiments in which cosmic radiation detectors were carried into space by Explorer VI and Pioneer V proved that any mechanism changing the cosmic-ray intensity over 11 years is centered about the sun. The scale size is > 1 astronomical unit for the volume of space in which the cosmic-ray intensity is reduced at this period of the solar activity cycle. Cosmic-ray flux was approximately constant from inside the terrestrial field far into the interplanetary medium. Therefore the 11-year depression of cosmic-ray intensity is not geocentric. A radial omnidirection intensity gradient of -(15 plus or minus 20)%/A was measured near the orbit of the earth and in the direction of the sun. This gradient showed that any electromagnetic-modulating mechanism required to account for the 11-year intensity variation is located principally outside the orbit of the earth. (M.C.G.)

• Research Organization: Univ. of Chicago
• NSA Number: NSA-14-026163
• OSTI ID: 4133900
• Journal Information: Phys. Rev. Letters, Journal Name: Phys. Rev. Letters Vol. Vol: 5
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

COSMIC RADIATION
EARTH
MAGNETIC FIELDS
MEASURED VALUES
MODULATION
ORBITS
PHYSICS
SATELLITES
SPACE
SPACE VEHICLES
SUN
VARIATIONS