A two-way sidereal anisotropy

The sidereal time variation is analyzed using data for the ion chambers at Cheltenham and Christchurch for the period 1938–58 and for the meson and neutron components during the IGY. All the results derived from these three kinds of data support the existence of a two-way sidereal anisotropy, suggested by Jacklyn, which has two maxima of the cosmic-ray intensity in the directions of 8 h and 20 h S.T. (sidereal time).

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The solar semidiurnal variation of cosmic-ray intensity 70 m.w.e. underground

Canadian Journal of Physics ◽

10.1139/p68-364 ◽

1968 ◽

Vol 46 (10) ◽

pp. S839-S843 ◽

Cited By ~ 4

Author(s):

G. Cini-Castagnoli ◽

M. A. Dodero ◽

L. Andreis

Keyword(s):

Diurnal Variation ◽

Cosmic Ray ◽

Fermi Acceleration ◽

Sidereal Time ◽

Cosmic Ray Intensity ◽

Intensity Measurements ◽

Hourly Data ◽

Semidiurnal Variation ◽

Order Of Magnitude ◽

Different Depths

Cosmic-ray intensity measurements have been carried out during the last year at a depth of 70 m.w.e. in the Monte dei Cappuccini laboratory in Torino, using solid vertical semicubical scintillator telescopes with a total area of 2 m2. Hourly data for 245 days corrected for barometric changes have been analyzed for the solar, apparent sidereal, and antisidereal daily variations whose harmonics are as follows:[Formula: see text]The true sidereal diurnal variation is estimated to have an amplitude of 0.019% with a time of maximum at 1720 h local sidereal time. The solar diurnal variation at different depths underground follows the energy dependence calculated with Axford's theory. The solar semidiurnal variation shows instead a fairly constant value at different μ energies. Its order of magnitude agrees with that expected as a result of Fermi acceleration in collisions of primaries moving in roughly solar and antisolar directions with solar wind inhomogeneities.

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Forbush decreases at different periods of the solar cycle

Canadian Journal of Physics ◽

10.1139/p68-368 ◽

1968 ◽

Vol 46 (10) ◽

pp. S859-S861

Author(s):

K. Imazhanova ◽

E. V. Kolomeets ◽

M. Musabaev ◽

V. T. Pivneva

Keyword(s):

Solar Activity ◽

Solar Cycle ◽

Cosmic Ray ◽

Particle Energy ◽

Forbush Decreases ◽

Cosmic Ray Intensity ◽

Recovery Times ◽

Using Data ◽

Neutron Component ◽

Worldwide Network

An analysis of Forbush decreases occurring at different periods of the solar cycle has been carried out using data from the worldwide network of stations registering the neutron component of the cosmic-ray intensity. The changes of energy spectrum of Forbush decreases have been investigated for the interval from 1957 to 1965, and also the dependence of the decrease and recovery times on particle energy and solar activity.

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Large-Scale Sidereal Anisotropy of Galactic Cosmic-Ray Intensity Observed by the Tibet Air Shower Array

The Astrophysical Journal ◽

10.1086/431582 ◽

2005 ◽

Vol 626 (1) ◽

pp. L29-L32 ◽

Cited By ~ 85

Author(s):

M. Amenomori ◽

S. Ayabe ◽

S. W. Cui ◽

Danzengluobu ◽

L. K. Ding ◽

...

Keyword(s):

Large Scale ◽

Cosmic Ray ◽

Cosmic Ray Intensity ◽

Air Shower ◽

Galactic Cosmic Ray ◽

Shower Array ◽

Sidereal Anisotropy ◽

Air Shower Array

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Rigidity spectra of primary cosmic radiation

Canadian Journal of Physics ◽

10.1139/p68-384 ◽

1968 ◽

Vol 46 (10) ◽

pp. S923-S926

Author(s):

K. Kasturirangan ◽

N. W. Nerurkar

Keyword(s):

Solar Activity ◽

North America ◽

Cosmic Radiation ◽

Cosmic Ray ◽

Cosmic Ray Intensity ◽

Slow Change ◽

Primary Cosmic Radiation ◽

Ion Chambers

The comparison of the cosmic-ray intensity measured with balloon-borne ion chambers at different atmospheric depths at stations in North America and in the U.S.S.R. for the period 1937–67 is presented. It is found that there is no difference in variations of cosmic-ray spectra in periods of increasing and decreasing solar activity in 1954–64. In 1937–40 the cosmic-ray spectra are found to be distinctly different, suggesting a slow change in the spectrum over periods greater than the 11-year cycle of solar activity.

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Semidiurnal Anisotropy of Galactic Cosmic Ray Intensity

Canadian Journal of Physics ◽

10.1139/p71-006 ◽

1971 ◽

Vol 49 (1) ◽

pp. 34-48 ◽

Cited By ~ 12

Author(s):

G. Subramanian

Keyword(s):

Energy Spectrum ◽

Counting Rate ◽

Interplanetary Space ◽

Cosmic Ray ◽

Cosmic Ray Intensity ◽

The Earth ◽

Positive Exponent ◽

Semidiurnal Variation ◽

Using Data ◽

Galactic Cosmic Ray

The semidiurnal variation of galactic cosmic ray intensity is investigated using data from mainly high counting rate neutron and meson monitors during 1964–1968. It is shown that in order to explain the observed semidiurnal variation it is necessary that an anisotropy of cosmic ray intensity be present in interplanetary space. The energy spectrum and the asymptotic latitude dependence of the anisotropy are then determined. The energy spectrum has a positive exponent close to + 1 for the power law in energy. The strength of the anisotropy decreases more rapidly than cosλ with increasing asymptotic latitude λ, both cos2λ and cos3λ being acceptable. The distribution of cosmic ray intensity in the range of heliolatitudes ± 7.25° at the orbit of the earth, obtained using data from the Ottawa neutron monitor, does not support the explanation of the semidiurnal variation based on the models of Subramanian and Sarabhai or Lietti and Quenby.

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