Counting rate of cosmic ray counter telescopes in inclined directions

1957 ◽  
Vol 6 (3) ◽  
pp. 735-738 ◽  
Author(s):  
D. A. Tidman ◽  
K. W. Ogilvie
Keyword(s):  
Counting Rate ◽  
Cosmic Ray

PERIODICAL FLUCTUATION STUDIES OF COSMIC-RAY DIURNAL VARIATIONS DURING THE QUIET-SUN PERIOD 1962–64

1967 ◽  
Vol 45 (8) ◽  
pp. 2733-2748 ◽  
Author(s):  
Masahiro Kodama
Keyword(s):  
Diurnal Variation ◽  
Solar Minimum ◽  
Counting Rate ◽  
Solar Rotation ◽  
Rotation Period ◽  
Cosmic Ray ◽  
Diurnal Variations ◽  
Statistical Studies ◽  
Periodic Fluctuations ◽  
Recurrence Tendency

Statistical studies of periodic fluctuations of the cosmic-ray diurnal variation have been performed, using neutron and meson component data obtained by the high-counting-rate cosmic-ray monitors at Deep River. The data cover an interval from May 1962 to October 1964, a period of descending solar activity ending near the solar minimum. It is shown that a 27-day recurrence tendency of the amplitude of the diurnal variation occasionally appears as well as shorter recurrent variations, ranging from one-half to one-sixth of the solar rotation period. The correlations of these fluctuations with some typical solar and terrestrial indices are examined in order to search for possible origins of the shorter recurrent variations. A possible connection with the Kp index exists.

The Propagation of Cosmic Radiation Through the Inter-Planetary Magnetic Field

1967 ◽  
Vol 1 (1) ◽  
pp. 29-30
Author(s):  
K. G. McCracken
Keyword(s):  
Magnetic Field ◽  
Energy Range ◽  
Cosmic Radiation ◽  
Counting Rate ◽  
Cosmic Ray ◽  
Alpha Particles ◽  
Statistical Precision ◽  
Degree Of Anisotropy ◽  
Planetary Magnetic Field ◽  
Cosmic Ray Flux

Instruments were flown on the Pioneer 6 and 7 spacecraft during 1965-66 to study the degree of anisotropy of cosmic radiation in the energy range 7.5-90 Mev/nucleón. The instruments record the cosmic ray fluxes from each of four contiguous ‘quadrants’ of azimuthal rotation of the spacecraft, for each of three energy windows 7.5-45 Mev, 45-90 Mev, and 150-350 Mev for alpha particles and heavier nuclei. In addition, the counting rate of all particles of energy >7.5 Mev is recorded, thereby providing cosmic ray data of high statistical precision useful in the study of fast changes in the cosmic ray flux.

Semidiurnal Anisotropy of Galactic Cosmic Ray Intensity

1971 ◽  
Vol 49 (1) ◽  
pp. 34-48 ◽  
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.

II. Cosmic-ray latitude survey in Canada in December, 1965

1969 ◽  
Vol 47 (19) ◽  
pp. 2051-2055 ◽  
Author(s):  
H. Carmichael ◽  
M. Bercovitch
Keyword(s):  
Sea Level ◽  
Environmental Effects ◽  
Neutron Monitor ◽  
High Latitude ◽  
Cosmic Radiation ◽  
Counting Rate ◽  
Cosmic Ray ◽  
Southern Boundary ◽  
Summer Survey ◽  
Made In

This, the second paper of a set of five, describes a small latitude survey, made in Canada in December, 1965, while the intensity of cosmic radiation was still within one per cent of its IQSY maximum. Flat sites at airports were used in the hope of eliminating environmental effects noted in the 1965 summer survey and particular care was taken to verify the barometric data. The objective was to improve upon the summer measurements as regards the boundary of the high-latitude plateau of the neutron-monitor intensity and it is believed that an intrinsic accuracy within 0.1% was achieved, but it was found that the NM-64 neutron-monitor counting rate was decreased about 0.5% by the presence of snow on the ground. The intensity near sea level appeared to be constant to the southern boundary of the survey at Windsor Airport (1.56 GV). The two most southerly sites, Windsor and Toronto (1.33 GV), were snow-free.

Effect of the Muon Contribution on the Barometric Coefficient of Neutron Monitors

1974 ◽  
Vol 2 (5) ◽  
pp. 304-305 ◽  
Author(s):  
T. T. Quang ◽  
A. G. Fenton ◽  
K. B. Fenton
Keyword(s):  
Neutron Monitor ◽  
Counting Rate ◽  
Cosmic Ray ◽  
Atmospheric Depth ◽  
Neutron Monitors ◽  
The Real ◽  
Obliquely Incident ◽  
Coefficient Versus ◽  
Depth Curve ◽  
Barometric Coefficient

The barometric coefficient of a cosmic-ray neutron monitor is found to increase with atmospheric depth from ~ 150 mm Hg to 600 mm Hg and then to decrease slowly with depth down to 760 mm Hg (Bachelet et al. 1965; Carmichael and Bercovitch 1969). Bachelet et al. 1965) tentatively attributed this change in the slope of the barometric coefficient versus atmospheric depth curve at 600 mm Hg to the contribution made by muons to the neutron monitor counting rate. Carmichael and Bercovitch (1969) have shown that the contribution to the monitor counting rate made by obliquely incident nucleons may be the real cause. Singh et al. (1970) have derived an expression for the barometric coefficient for vertically incident particles in a neutron monitor which increases continuously with increasing atmospheric depth down to 760 mm Hg, demonstrating more definitely that the above explanation of Carmichael and Bercovitch is correct.

scholarly journals The Cosmic X-Ray Background

1968 ◽  
Vol 1 ◽  
pp. 220-227
Author(s):  
R. J. Weymann
Keyword(s):  
Counting Rate ◽  
Solid Angle ◽  
Cosmic Ray ◽  
Reasonable Doubt ◽  
X Ray ◽  
X Ray Background

Evidence for a diffuse, isotropic non-terrestrial component of X-ray radiation has been accumulating since the very beginnings of X-ray astronomy. This evidence now seems secure beyond reasonable doubt, especially in the light of recent experiments, e.g. one in which a very clean separation from the cosmic ray and terrestrial background has been achieved (Pounds, 1967), and another in which a counting rate proportional to the solid angle of the sky subtended to three different detectors was found (Matsuoka et al., 1967).In this very brief review I wish simply to discuss the current ideas on the mechanisms for the production of the background and the extent to which the present observations can discriminate between them and to consider the information obtainable from the very soft X-ray region, which so far has been relatively little exploited.

Cosmic Ray Stömer Cut-offs on the Surface of Jupiter

1974 ◽  
Vol 2 (5) ◽  
pp. 296-297 ◽  
Author(s):  
D. J. Cooke
Keyword(s):  
Magnetic Field ◽  
Counting Rate ◽  
Cosmic Ray ◽  
Field Of View ◽  
Line Of Sight ◽  
The Earth

It has recently been reported (Cini-Castagnoli et al. 1973; Jacklyn and Cini-Castagnoli, 1974) that Jupiter may be responsible for a modulation component in the counting rate of underground cosmic ray detectors on the earth. The evidence suggests that a screening mechanism is operating, in as much as the observed counting rates are diminished when Jupiter is within the field of view of these detectors. The magnitude of the effect is larger than can be accounted for by simple line-of-sight obscuration by the planet itself, and it has been suggested that the intense and extensive Jovian magnetic field is producing the effect.

Search for low-energy interplanetary positrons

1968 ◽  
Vol 46 (10) ◽  
pp. S527-S529 ◽  
Author(s):  
T. L. Cline ◽  
E. W. Hones Jr.
Keyword(s):  
Counting Rate ◽  
Cosmic Ray ◽  
Primary Component ◽  
Low Energy ◽  
Charge Ratio ◽  
Great Abundance ◽  
Independent Source ◽  
Equilibrium Charge ◽  
Energy Dependent ◽  
Background Effect

Preliminary results of an experiment designed to detect and measure the intensity of interplanetary positrons of energy 0–3 MeV with the satellites OGO-I and OGO-III are outlined. Evidence for a statistically significant counting rate of detected positrons is presented, and the possibility that these particles represent a true primary component rather than a background effect, such as cosmic-ray induced secondaries in the detector, is considered. It is shown that the apparent intensity of low-energy positrons, assuming that value derived from their counting rate, would be consistent with an equilibrium charge ratio. This result would not be predicted with mechanisms involving the ionization of matter or the acceleration of electrons, but would be consistent with a strongly energy-dependent galactic trapping parameter allowing meson-decay electrons to slow down in great abundance, or with the existence of an independent source.

Sign in / Sign up

Export Citation Format

Share Document