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.

III. Cosmic-ray latitude survey in Western USA and Hawaii in summer, 1966

1969 ◽  
Vol 47 (19) ◽  
pp. 2057-2065 ◽  
Author(s):  
H. Carmichael ◽  
M. A. Shea ◽  
R. W. Peterson
Keyword(s):  
Sea Level ◽  
Neutron Monitor ◽  
Cosmic Radiation ◽  
Measuring Equipment ◽  
Cosmic Ray ◽  
Temperature Structure ◽  
Western Usa ◽  
Secular Variations ◽  
The Usa ◽  
Different Levels

A 3-NM-64 neutron monitor and a 2-MT-64 muon monitor were operated at 29 sites near sea level and on mountains on the western seaboard of the USA and in Hawaii in May, June, and July, 1966, in continuation of the latitude survey begun in 1965 and reported in papers I and II of this set of five papers. The original results and also the corrections for temperature structure of the atmosphere and for secular variations of the cosmic radiation are given in detail. While the overland equipment was at its highest altitude on Mt. Hood (2.4 GV) and on the summits of Mt. Palomar (5.7 GV) and Mt. Haleakela (13.3 GV), an airborne neutron monitor was operated at seven different levels between 3000 m and 12 000 m. The pressure-measuring equipment and also the neutron monitor in the aircraft were calibrated in terms of the overland instruments while the aircraft was at the same altitude as the overland equipment on the summit of Mt. Haleakela.

I. Cosmic-ray latitude survey in North America in summer, 1965

1969 ◽  
Vol 47 (19) ◽  
pp. 2037-2050 ◽  
Author(s):  
H. Carmichael ◽  
M. Bercovitch ◽  
J. F. Steljes ◽  
M. Magidin
Keyword(s):  
North America ◽  
Sea Level ◽  
Cosmic Radiation ◽  
Cosmic Ray ◽  
Pressure Level ◽  
Temperature Structure ◽  
Instrumental Effects ◽  
Secular Variations ◽  
The Usa ◽  
Made In

A 3-NM-64 neutron monitor and a 2-MT-64 muon monitor were operated overland at 44 sites near sea level and on mountains in Canada, the USA, and Mexico in April, May, and June, 1965, when the intensity of cosmic radiation attained its 11-year maximum. The equipment is briefly described and the original results of the measurements are listed. Some necessary corrections for instrumental effects are discussed. The corrections made to eliminate the secular variations of the cosmic radiation and the dependence upon temperature structure of the atmosphere are given in detail. This paper is the first of a set of five dealing with latitude surveys made in 1965 and 1966. Reduction of the observations to a common pressure level is carried out in the final paper of the set.

scholarly journals Observing the neutron component during thunderstorm activity at a mountain CR station

2019 ◽  
Vol 5 (3) ◽  
pp. 54-58
Author(s):  
Анна Луковникова ◽  
Anna Lukovnikova ◽  
Виктор Алешков ◽  
Viktor Aleshkov ◽  
Алексей Лысак ◽  
...  
Keyword(s):  
Field Strength ◽  
Sea Level ◽  
Neutron Monitor ◽  
Electromagnetic Interference ◽  
Count Rate ◽  
Cosmic Ray ◽  
Thunderstorm Activity ◽  
Signal Discrimination ◽  
Lightning Discharges ◽  
Neutron Component

During three summer months in 2015, the Cosmic Ray (CR) station Irkutsk-3000, located at 3000 m above sea level, measured the CR neutron component intensity with the 6NM64 neutron monitor, as well as the atmospheric electric field strength and the level of electromagnetic interference during lightning discharges. It is shown that the level of electromagnetic interference, when registered during lightning discharges, depends considerably on the fixed level of signal discrimination. During observations, we observed no effects of thunderstorm discharges at the neutron monitor count rate at the CR station Irkutsk-3000.

The long-term variation of the cosmic radiation

1968 ◽  
Vol 46 (10) ◽  
pp. S903-S906 ◽  
Author(s):  
J. A. Lockwood ◽  
W. R. Webber
Keyword(s):  
Neutron Monitor ◽  
Cosmic Radiation ◽  
Cosmic Ray ◽  
Solar Modulation ◽  
Neutron Monitors ◽  
Cosmic Ray Intensity ◽  
Direct Measurements ◽  
Term Variation ◽  
Primary Cosmic Radiation

The variation in the cosmic-ray intensity recorded by neutron monitors from 1958 to 1965 has been investigated to deduce the form of the solar modulation of the cosmic radiation. The observed changes in the intensity at the neutron monitor stations, averaged over quarter-year periods, were compared with changes calculated using modulation functions depending upon energy, rigidity, and velocity × rigidity. These calculations were based upon the revised differential response functions deduced by Lockwood and Webber (1967). The variance between the observed and calculated changes in the neutron monitor intensities at different stations was minimized to determine the best form of the solar modulation function. We find that the change of the primary cosmic radiation, deduced from the change in the neutron monitor intensity as well as from direct measurements of the primary flux, can be described by a modulation of the form exp(–K/P) in the rigidity range 0.5 < P < 50 GV. The change between 1959 and 1965 can be fitted with K = 1.94 ± 0.09 and between 1963 and 1965 with K = 0.36 ± 0.05.

Cosmic-ray flux variation with height in the atmosphere

1968 ◽  
Vol 46 (10) ◽  
pp. S1020-S1022 ◽  
Author(s):  
B. S. Chow ◽  
K. K. Wu ◽  
N. Simpson ◽  
V. D. Hopper
Keyword(s):  
Cosmic Radiation ◽  
Cosmic Ray ◽  
Geiger Counter ◽  
Proton Flux ◽  
Atmospheric Depth ◽  
Altitude Range ◽  
Flux Variation ◽  
Star Production ◽  
Cosmic Ray Flux ◽  
Made In

Analysis of emulsions exposed to cosmic radiation at atmospheric depths between 10 and 40 g/cm2 at λ = 47 °S geomagnetic on 11 December 1964 shows that there is little variation with altitude in proton flux in this altitude range. However, the total star production rate increases with increasing atmospheric depth but with a smaller slope than that measured by Geiger counter. Preliminary results obtained from exposures made in November 1965 at 8.5, 28.4, and 58 g/cm2 show that the values of proton flux at 8.5 and 58 g/cm2 are lower than that at 28.4 g/cm2. A study of the rate of production of stars at λ = 43° S and 9 g/cm2 over the period April 1962 to September 1966 shows some correlation with the ground-based neutron monitor count rate. The proton flux at the top of the atmosphere at latitude 47° S is estimated as 900 ± 100 protons/m2 sr s.

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.

scholarly journals Pretoria Radiocarbon Dates I

Radiocarbon ◽  
1971 ◽  
Vol 13 (2) ◽  
pp. 378-394 ◽  
Author(s):  
J. C. Vogel ◽  
M. Marais
Keyword(s):  
Sea Level ◽  
Neutron Monitor ◽  
Cosmic Radiation ◽  
Research Laboratory ◽  
Radiocarbon Dating ◽  
Physical Research Laboratory ◽  
Radiocarbon Dates ◽  
Physical Research ◽  
Nucleonic Component

In 1969 radiocarbon dating facilities were established at the National Physical Research Laboratory of the C.S.I.R. in Pretoria (25° 43′ S Lat, 28° 21′ E Long; alt 1500 m). The counters are situated in an underground room built of selected concrete and covered by ca. 12 m earth. In this room, the nucleonic component of cosmic radiation is practically absent and the meson flux is reduced by a factor of 3.5 as compared to the surface at sea level in Groningen, Netherlands. A neutron monitor which registers 30 cpm on the surface, counts ca. 0.1 cpm in the underground room.

Variation with Zenith Angle of the Integral Intensity of Muons near Sea Level

1972 ◽  
Vol 50 (8) ◽  
pp. 843-848 ◽  
Author(s):  
R. W. Flint ◽  
R. B. Hicks ◽  
S. Standil
Keyword(s):  
Theoretical Model ◽  
Sea Level ◽  
Zenith Angle ◽  
Integral Intensity ◽  
Cosmic Ray ◽  
Muon Flux ◽  
Experimental Measurements ◽  
A Current ◽  
Made In

The integral intensity of the cosmic ray muon flux (> 0.28 GeV/c) near sea level has been measured in the zenith angle range 75–90°. Very few other experimental measurements have been made in this range. The present results agree closely with the predictions of a current theoretical model except at very large zenith angles, where the measured intensities are somewhat higher than predicted.

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.

A STATISTICAL ANALYSIS OF THE BAROMETER COEFFICIENTS FOR COSMIC-RAY INTENSITIES

1962 ◽  
Vol 40 (6) ◽  
pp. 687-697 ◽  
Author(s):  
S. M. Lapointe ◽  
D. C. Rose
Keyword(s):  
Statistical Analysis ◽  
Sea Level ◽  
Neutron Monitor ◽  
Seasonal Variations ◽  
Geomagnetic Latitude ◽  
Cosmic Ray ◽  
Seasonal Fluctuations ◽  
Latitude Effect ◽  
Standard Neutron ◽  
The One

The data from all four Canadian cosmic-ray stations, Ottawa, Resolute, Churchill, and Sulphur Mountain, have been analyzed statistically with the help of an I.B.M. 650 computer over a period of three and a half years extending from the beginning of the I.G.Y. in July 1957 to the end of 1960. The barometer coefficients for triple and double coincidences in the international cubical telescope and for the nucleon intensity in the standard neutron monitor have been derived. A single correlation between intensity and pressure was used; two different ways of effecting this correlation were tried over a 6-month period. The results were compared and the best method was applied to the remaining three years. Monthly values were calculated, as were yearly values and also values for the 3-year period. The results reveal no significant seasonal variations in the barometer coefficients and no significant year-to-year variation. However, the seasonal fluctuations of the nucleon coefficient unsuspectedly follow those of the meson. A small latitude effect seems to be present. The nucleon coefficient at Sulphur Mountain, a high altitude station, is larger than the one at Ottawa (same geomagnetic latitude, sea level station).

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