Remarks on the Latitude Effect of Cosmic Rays at Sea-Level

1950 ◽  
Vol 3 (2) ◽  
pp. 183
Author(s):  
HD Rathgeber
Keyword(s):  
Cosmic Rays ◽  
Sea Level ◽  
Zenith Angle ◽  
Incident Radiation ◽  
Geiger Counter ◽  
Angle Distribution ◽  
High Latitudes ◽  
Latitude Effect ◽  
Counter Telescope ◽  
East West

During a recent voyage from Australia to Japan the intensity of cosmic rays was measured with several Geiger counter telescopes of different designs. The conclusions to be drawn from these and other results are presented in this paper. It is shown that the latitude effect at sea-level (averaged over all azimuths) is approximately proportional to cos2 1.2ζ, where ζ is the zenith angle of the incident radiation, and that the vertical latitude effect is 18 per cent. In general, the latitude effect depends both on zenith angle and azimuth. The phenomenological relationships of these intensity variations with the zenith angle distribution at two fixed locations, i.e. at high latitudes and at the equator, and with the east-west effect at the equator, are deduced. After correction for longitude and zenith angle, Geiger counter telescope and ionization measurements do not differ by more than their errors of measurements ; the average specific ionization does not vary with latitude. Qualitative explanations of the equality of the latitude effects for mesons and for electrons, as well as of the latitude effect of small extensive showers are given.

RESPONSE OF MU-MESON DETECTORS DEEP IN THE ATMOSPHERE TO PRIMARY COSMIC-RAY PARTICLES OF MAGNETIC RIGIDITY BETWEEN 10 AND 25 GV

1967 ◽  
Vol 45 (5) ◽  
pp. 1643-1653 ◽  
Author(s):  
T. Mathews ◽  
G. G. Sivjee
Keyword(s):  
Sea Level ◽  
Scintillation Counter ◽  
Cosmic Ray ◽  
Decay Rates ◽  
Atmospheric Effects ◽  
Ionization Chambers ◽  
Corrected Data ◽  
Counter Telescope ◽  
East West ◽  
Different Altitudes

The cosmic-ray mu-meson intensities at three different altitudes at the equator were measured as a function of zenith and azimuth angles by means of a portable scintillation counter telescope of semi-opening angles 23°. The data were analyzed to assess the effects of differences in pi- and mu-meson decay rates on the intensity of the penetrating ionizing component at different zenith angles. It was found that the changes of intensity as a function of zenith angles could be attributed almost entirely to differences in atmospheric absorption, provided that at all zenith angles the threshold rigidities were the same. Hence the intensities measured at different zenith angles in the east–west plane at the equator could be corrected to remove the atmospheric effects and the corrected data used for determining the response of meson detectors at sea level to particles of rigidity up to 25 GV. The response curve thus obtained is presented and compared with that obtained from sea-level latitude surveys by means of ionization chambers.

The High Latitude East-West -Asymmetry of Cosmic Rays

1952 ◽  
Vol 5 (1) ◽  
pp. 47 ◽  
Author(s):  
DWP Burbury ◽  
KB Fenton
Keyword(s):  
Cosmic Rays ◽  
Sea Level ◽  
High Latitude ◽  
Macquarie Island ◽  
East West

Measurements of the east-west asymmetry of cosmic rays at sea-level have been made at Hobart and Macquarie Island in geomagnetic latitudes 51.7 and 60.7 �S. respectively. The values obtained have been found to agree satisfactorily with values calculated using a revised form of Johnson's theory.

LATITUDE EFFECT OF THE COSMIC RAY NUCLEON AND MESON COMPONENTS AT SEA LEVEL FROM THE ARCTIC TO THE ANTARCTIC

1956 ◽  
Vol 34 (9) ◽  
pp. 968-984 ◽  
Author(s):  
D. C. Rose ◽  
K. B. Fenton ◽  
J. Katzman ◽  
J. A. Simpson
Keyword(s):  
Sea Level ◽  
Cosmic Ray ◽  
The Arctic ◽  
High Latitudes ◽  
Geomagnetic Equator ◽  
Northern Latitudes ◽  
Latitude Effect ◽  
Nucleonic Component ◽  
The Antarctic ◽  
Eccentric Dipole

Results are presented of cosmic ray measurements taken at sea level during 1954–55 from the Arctic to the Antarctic. The equipment consisted of a neutron monitor and a meson telescope. Latitude effects of 1.77 for the nucleonic component and 1.15 for the meson component were measured. The longitude effect at the equator was much less than expected on the basis of the geomagnetic eccentric dipole and the longitude effect at intermediate northern latitudes shows that the longitude of the effective eccentric dipole is considerably west of that of the geomagnetic eccentric dipole. In a previous paper by the same authors, the positions of the equatorial minima were combined with other published cosmic ray measurements to calculate a new cosmic ray geomagnetic equator. In this paper new coordinates are derived on the assumption that these equatorial coordinates apply to a new eccentric dipole, and, therefore, that the equatorial coordinates may be extended to high latitudes. When the complete results are plotted on these coordinates, it is found that an eccentric dipole representation of the earth's magnetic field is inconsistent with the combined observations at all latitudes.

THE ALTITUDE EFFECT ON THE SPECIFIC IONIZING POWER AND ZENITH ANGLE DISTRIBUTION OF COSMIC RAYS

1938 ◽  
Vol 16a (2) ◽  
pp. 29-40 ◽  
Author(s):  
Darol K. Froman ◽  
J. C. Stearns
Keyword(s):  
Cosmic Rays ◽  
Zenith Angle ◽  
Ionization Chamber ◽  
Unit Area ◽  
Cosmic Ray ◽  
Angle Distribution ◽  
Altitude Effect ◽  
Counting System ◽  
Chamber Measurements ◽  
Zenith Angle Distribution

Measurements made with a quadruple-coincidence Geiger-Müller counting system at altitudes of 120 and 14,160 ft. give the intensity, J, of cosmic ray ionizing particles at various zenith angles, ψ. The distribution, J(ψ) = J0e−0.175ψ cos2ψ, does not differ significantly from any measured values, and agrees with all observations within 0.5 and 3.0% of the vertical intensities at the lower and higher altitudes respectively. The total number of rays incident per unit area per unit time was found, and the specific ionization was determined by comparison with ionization chamber measurements. The results are given below.[Formula: see text]† Ionization chamber data from Clay and Jongen (4).* Ionization chamber data from Millikan and Cameron (18).

THE GEOMAGNETIC LATITUDE EFFECT ON THE NUCLEON AND MESON COMPONENT OF COSMIC RAYS AT SEA LEVEL

1956 ◽  
Vol 34 (1) ◽  
pp. 1-19 ◽  
Author(s):  
D. C. Rose ◽  
J. Katzman
Keyword(s):  
Cosmic Rays ◽  
Sea Level ◽  
North American ◽  
Geomagnetic Latitude ◽  
Vertical Direction ◽  
Temperature Correction ◽  
The Arctic ◽  
High Latitudes ◽  
Primary Spectrum ◽  
The North

Measurements have been taken on the changes in intensity of the nucleon and meson components of cosmic rays during a cruise of the Canadian Naval Icebreaker Labrador into the Arctic, through the North West Passage, and circumnavigating the North American Continent. The geomagnetic latitudes covered extend from 18°N. to 89°N. The latitude knee is clearly shown at a geomagnetic latitude of about 52° in the case of the nucleon component and less definitely between 40° and 50° in the case of the meson component. The rigidity of particles arriving in a vertical direction at 52° is 2.1 Bv. and at 45° is 3.7 Bv. Meyer and Simpson have shown that changes in the primary spectrum between 1948 and 1954 probably extend up to these rigidities and such changes should, therefore, be observable at sea level. The longitude effect at low latitudes is clearly shown by differences in intensity between the measurements on the east and west sides of North America. In the case of the meson component, the magnitude of the longitude effect at these longitudes was found to be greater than that shown by Millikan and Neher in 1936. The interpretation of the meson component results above the knee is complicated by difficulties in temperature correction. In the case of the nucleon component, an apparent longitude effect exists above the knee in that there was a small difference in the intensity at high latitudes in the eastern and western parts of the North American Arctic. No satisfactory explanation is offered for this. The diurnal variation of the nucleon component at high latitudes is shown but no unusual features were found. Appreciation is expressed to the Royal Canadian Navy for making these measurements possible.

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