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.

A study of secondary cosmic ray flux variation during the annular eclipse of 15 January 2010 at Rameswaram, India

2011 ◽  
Vol 35 (5) ◽  
pp. 223-229 ◽  
Author(s):  
Ankush Bhaskar ◽  
Avadhut Purohit ◽  
M. Hemalatha ◽  
Chintamani Pai ◽  
Anil Raghav ◽  
...  
Keyword(s):  
Cosmic Ray ◽  
Flux Variation ◽  
Cosmic Ray Flux

scholarly journals The distribution of cosmic-ray ionization rates in diffuse molecular clouds as probed by H 3 +

2012 ◽  
Vol 370 (1978) ◽  
pp. 5142-5150 ◽  
Author(s):  
Nick Indriolo
Keyword(s):  
Molecular Clouds ◽  
Cosmic Ray ◽  
Ionization Rate ◽  
Line Of Sight ◽  
Interstellar Clouds ◽  
Upper Limits ◽  
The Galaxy ◽  
Cosmic Ray Flux ◽  
Made In ◽  
Ionization Rates

Owing to its simple chemistry, H is widely regarded as the most reliable tracer of the cosmic-ray ionization rate in diffuse interstellar clouds. At present, H observations have been made in over 50 sight lines that probe the diffuse interstellar medium (ISM) throughout the Galaxy. This small survey presents the opportunity to investigate the distribution of cosmic-ray ionization rates in the ISM, as well as any correlations between the ionization rate and line-of-sight properties. Some of the highest inferred ionization rates are about 25 times larger than the lowest upper limits, suggesting variations in the underlying low-energy cosmic-ray flux across the Galaxy. Most likely, such variations are caused predominantly by the distance between an observed cloud and the nearest site of particle acceleration.

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 Study of the Parameters Affecting the Correlation of Background Versus Cosmic Radiation in Co2 Counters: Reliability of Dating Results

Radiocarbon ◽  
1997 ◽  
Vol 39 (3) ◽  
pp. 225-238 ◽  
Author(s):  
Yorgos Facorellis ◽  
Yannis Maniatis ◽  
Bernd Kromer
Keyword(s):  
Solar Flares ◽  
Cosmic Radiation ◽  
Cosmic Ray ◽  
Simple Extension ◽  
Statistical Fluctuations ◽  
Fitting Procedure ◽  
One Year ◽  
Cosmic Ray Flux

Systematic treatment of the data recorded by our guard counters and corrections introduced for meteorological factors has allowed observations on solar events clearly manifested in the readings. Examples are the solar flares of March 1989 and especially of June 1991, which caused a ca. 10% decrease in the cosmic radiation flux reaching the counters. A sinusoidal variation in the cosmic-ray flux with a period of one year is also clearly manifested in the data. The observation that the background in the 14C measurements depends on the intensity of the cosmic radiation has led to the use of monthly correlations for the determination of the best background value to be used in the age calculations. This reduces the error significantly. However, various factors such as random statistical fluctuations of the background measurements may affect the slope of the correlations and consequently the calculated age of the samples. Long-term observations of the relation between background values and coincidence counts have led to constraints in the slope of the correlation. A simple extension of the fitting procedure is explored, which maintains the physically meaningful range of the slopes, but is flexible to adjust for the seasonally varying contributions to the variations of the cosmic-ray flux.

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 PECULIARITIES OF HARD COSMIC RADIATION VARIATIONS NEAR THE GROUND SURFACE IN ACCORDANCE WITH GEOMAGNETIC ACTIVITY CHANGES

2004 ◽  
Vol 12 (3) ◽  
pp. 96-102 ◽  
Author(s):  
Dmitrijus Styra ◽  
Jonas Gaspariūnas ◽  
Ana Usovaite
Keyword(s):  
Cosmic Radiation ◽  
Nuclear Reactions ◽  
Ground Surface ◽  
Cosmic Ray ◽  
Initial Energy ◽  
Atmospheric Gases ◽  
Existence Time ◽  
Cosmic Particle ◽  
Hard Cosmic Ray Flux ◽  
Cosmic Ray Flux

The mechanism of primary cosmic particle transformation into secondary radiation near the ground surface is analysed. It is known that the main part of secondary cosmic radiation consists of muons. They are formed after nuclear reactions between primary protons and the nuclei of atmospheric gases. Maximum muon concentrations are formed at an altitude of 15 km from the ground surface. Because of a short existence time of muons (2 μs), the amount of these particles near the ground surface depends on variations in the altitude of the above‐mentioned atmospheric layer. Therefore, an unstable flux of muons is registered near the ground surface. Their variations are connected with the Sun's radiation instability, geomagnetic field variations, meteorological process changes, etc. Measurements of the hard cosmic radiation component only near the ground surface are carried out. To this purpose protection of the detector of gamma‐spectrometer was improved. Small gaps between lead plates were made to abolish the shower phenomenon caused by cosmic radiation and the effect of weak‐energy particles and as a result to improve the measurement accuracy. It is defined that lead protection of the thickness of 9 cm of the detector fully absorbs muons with 1,6 MeV energy. It is registered that the gamma‐quanta of 1,6 MeV energy of radionuclide 232Th lose 70 % of the initial energy only in the same lead protection. In 2001–2002 a study was made of the course of the hard cosmic ray flux (HCRF) near the ground surface in four energy intervals: 1 ‐ 0,3–1,2 MeV, 2 ‐ 1,2–1,6 MeV, 3 ‐ 1,6—4 MeV, 4–4 MeV and more. Various course of the HCRF in the mentioned intervals is obtained.

scholarly journals The Regener-Pfotzer Maximum During a Total Solar Eclipse

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Gordon McIntosh ◽  
Alaina Swanson ◽  
Liam Taylor ◽  
Erick Paul Agrimson ◽  
Kaye Smith ◽  
...  
Keyword(s):  
High Altitude ◽  
Solar Eclipse ◽  
Radiation Intensity ◽  
Cosmic Radiation ◽  
Cosmic Ray ◽  
Total Solar Eclipse ◽  
Interaction Layer ◽  
The Earth ◽  
Cosmic Ray Flux

The Regener-Pfotzer (RP) maximum is the altitude at which cosmic radiation intensity is the greatest. A decrease of the altitude of the interaction layer, assumed to be measured by the RP maximum, has been suggested to account for a reduction in the secondary cosmic ray flux measured at the surface of the Earth during a total solar eclipse. To investigate this suggestion, high altitude cosmic radiation was measured using Geiger Mueller (GM) counters carried beneath weather balloons both before and during the total solar eclipse on 21 August 2017. The 19 and 20 August 2017 omnidirectional RP maxima occurred at an average altitude of 20.2 km ± 0.9 km. During the eclipse of 21 August 2017 the omnidirectional RP maxima occurred at an altitude of 20.4 km ± 0.8 km. The 19 and 20 August 2017 vertical coincidence RP maxima occurred at an altitude of 18.3 km ± 1.0 km. During the eclipse the vertical coincidence RP maxima occurred at 18.0 km ± 1.0 km. Our results do not show any decrease in the altitude of either the omnidirectional or the vertical coincidence RP maximum outside the range of our measurements before the eclipse.

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.

The charge spectrum of very heavy cosmic ray nuclei

1970 ◽  
Vol 318 (1532) ◽  
pp. 1-43 ◽  
Keyword(s):  
Neutron Capture ◽  
Cosmic Radiation ◽  
Previous Experiment ◽  
Cosmic Ray ◽  
Photographic Emulsion ◽  
Heavy Nuclei ◽  
Detailed Consideration ◽  
Charge Spectrum ◽  
Made In

Large areas of photographic emulsion have been flown on balloons, at small atmospheric depths, in order to record tracks of relativistic highly charged nuclei of the cosmic radiation. Sixty tracks due to relativistic nuclei with Z > 40 have been found and the resulting charge spectrum is presented. One nucleus with Z > 90 penetrated the detector, indicating a lower flux of extremely heavy nuclei than was suggested by the previous experiment (Fowler, Adams, Cowen & Kidd 1967). The observed structure in the charge spectrum again suggests that nuclei of the cosmic radiation have been synthesized by the process of rapid neutron capture. Detailed consideration is given to the fundamental assumptions made in the interpretation of the measurements and assignment of the charges.

Sign in / Sign up

Export Citation Format

Share Document