Cosmic-ray fluctuations in interplanetary space

The daily variation of cosmic ray intensity at low latitudes can under certain conditions be associated with an anisotropy of primary radiation. During 1957-8, this anisotropy had an energy spectrum of variation of the form aϵ -0.8±0.3 and corresponded to a source situated at an angle of 112 ± 10° to the left of the earth-sun line. The daily variation which can be associated with a local source situated along the earth-sun line has an energy spectrum of variation of the form aϵ 0 . Increases in east-west asymmetry and the associated daily variation for east and west directions can be explained by the acceleration of cosmic ray particles crossing beams of solar plasma in the neighbourhood of the earth. For beams of width 5 x 10 12 cm with a frozen magnetic field of the order of 10 -4 G, a radial velocity of about 1.5 x 108 cm/s is required. The process is possible only if the ejection of beams takes place in rarefied regions of inter planetary space which extend radially over active solar regions. An explanation of Forbush, type decreases observed at great distances from the earth requires similar limitation on the plasma density and conductivity of regions of interplanetary space. The decrease of east-west asymmetry associated with world-wide decreases of intensity and with SC magnetic storms is consistent with a screening of the low-energy cosmic ray particles due to magnetic fields in plasma clouds.

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39. The anisotropy of primary cosmic radiation and the electromagnetic state in interplanetary space

Symposium - International Astronomical Union ◽

10.1017/s0074180900237959 ◽

1958 ◽

Vol 6 ◽

pp. 377-385

Author(s):

V. Sarabhai ◽

N. W. Nerurkar ◽

S. P. Duggal ◽

T. S. G. Sastry

Keyword(s):

Experimental Data ◽

Cosmic Rays ◽

Cosmic Radiation ◽

Interplanetary Space ◽

Daily Variation ◽

Cosmic Ray ◽

The Sun ◽

Cosmic Ray Intensity ◽

Daily Variations ◽

Primary Cosmic Radiation

Study of the anisotropy of cosmic rays from the measurement of the daily variation of meson intensity has demonstrated that there are significant day-today changes in the anisotropy of the radiation. New experimental data pertaining to these changes and their solar and terrestrial relationships are discussed.An interpretation of these changes of anisotropy in terms of the modulation of cosmic rays by streams of matter emitted by the sun is given. In particular, an explanation for the existence of the recently discovered types of daily variations exhibiting day and night maxima respectively, can be found by an extension of some ideas of Alfvén, Nagashima, and Davies. An integrated attempt is made to interpret the known features of the variation of cosmic ray intensity in conformity with ideas developed above.

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Time Structure of Solar Flare Proton Events

Publications of the Astronomical Society of Australia ◽

10.1017/s1323358000011139 ◽

1968 ◽

Vol 1 (4) ◽

pp. 148-149

Author(s):

B. J. Stone

Keyword(s):

Solar Flare ◽

Interplanetary Space ◽

Cosmic Ray ◽

Solar Proton ◽

Progress Report ◽

Flare Activity ◽

Space Probe ◽

Short Term ◽

The Earth ◽

The Times

This paper is a progress report on an examination of the short-term variability of solar proton flux in interplanetary space at times of solar flare activity. The data are from the GRCSW cosmic-ray detector on board the Pioneer 7 space probe, which, at the times to be discussed, was more than a million miles from the Earth.

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Cosmic-ray diffusion coefficient in interplanetary space

Journal of Geophysical Research Atmospheres ◽

10.1029/ja077i022p04259 ◽

1972 ◽

Vol 77 (22) ◽

pp. 4259-4263 ◽

Cited By ~ 7

Author(s):

L. J. Gleeson ◽

I. H. Urch

Keyword(s):

Diffusion Coefficient ◽

Interplanetary Space ◽

Cosmic Ray ◽

Ray Diffusion

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