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 Structure of Cosmic Ray Air Showers

1949 ◽  
Vol 2 (2) ◽  
pp. 184
Author(s):  
CBO Mohr
Keyword(s):  
High Pressure ◽  
Sea Level ◽  
Cosmic Ray ◽  
Low Density ◽  
Air Showers ◽  
Ionization Chambers ◽  
Single Chamber ◽  
Transition Effect ◽  
The Core ◽  
Rate Frequency

The structure of cosmic ray air showers at sea-level has been studied by an investigation of the burst rate frequency and the transition effect in lead, for cosmic ray bursts occurring simultaneously in two high-pressure ionization chambers with varying separation. Although extensive showers were responsible for all the coincidences observed with the larger chamber separations, they accounted for less than 3 per cent, of the bursts observed with a single chamber. Of the remaining 97 per cent., somewhat more than one-half appear to be due to nuclear disintegrations and the rest either to narrow showers of approximate radius 30 cm. or to the core of an extensive shower of low density. The extensive shower frequency was about 10 times that predicted by theory. The bearing of these results on present views of the origin and development of air showers is discussed.

Cosmic-ray proton and helium spectra and solar modulation effects in the new solar cycle measured with a four-element counter telescope

1968 ◽  
Vol 46 (10) ◽  
pp. S883-S886 ◽  
Author(s):  
J. F. Ormes ◽  
W. R. Webber
Keyword(s):  
Scintillation Counter ◽  
Pulse Height ◽  
Cosmic Ray ◽  
Geometrical Factor ◽  
Solar Modulation ◽  
Primary Proton ◽  
Before And After ◽  
Order Of Magnitude ◽  
Helium Spectra ◽  
Counter Telescope

In the summers of 1965 and 1966 we have continued our studies begun in 1963 on the primary proton and helium spectra and the effects of solar modulation. Data are available from four additional balloon flights at Fort Churchill using the earlier version of the Cerenkov-scintillation counter telescope (Ormes and Webber 1966), and a new four-element double-scintillation (dE/dx), Cerenkov-scintillation + range telescope. This latest telescope employs pulse-height analysis on both dE/dx counters and the Cerenkov-scintillation counter. Various consistency requirements may be set between pulse heights. These serve to reduce background effects by an order of magnitude over the previous system. The geometrical factor of the telescope is 55.4 sr cm2. The results reported here will cover the proton and helium spectra from 100 MeV/nucleon to 2 BeV/nucleon and their time variation. They will show that the fractional changes in the differential proton spectra can be represented by (rigidity)−1 both before and after the sunspot minimum and that there is no evidence for any hysteresis effects between protons of 100 MeV to 2 BeV and energies to which neutron monitors respond.

IONIZING POWER OF COSMIC RAY PARTICLES AT SEA LEVEL

1951 ◽  
Vol 29 (6) ◽  
pp. 495-504 ◽  
Author(s):  
S. D. Chatterjee
Keyword(s):  
Sea Level ◽  
Distribution Curve ◽  
Pulse Height ◽  
Cosmic Ray ◽  
Relativistic Electrons ◽  
Height Distribution ◽  
Soft Component ◽  
Pulse Height Distribution ◽  
Counter Telescope ◽  
Number Of Particles

Using a proportional counter telescope arrangement, experiments have been carried out at sea level to explore the nature and ionizing power of particles in the soft component of cosmic radiation and those produced under 1.8 cm. and 20 cm. of lead. The results indicate a preponderance of relativistic electrons in the soft component and under 20 cm. of lead. Under 1.8 cm. of lead there is some disagreement with the calculated pulse height distribution curve but this can be attributed to the production of showers in the lead. These showers would obscure the presence of a small number of particles of unusually high ionizing power, if such exist.

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.

Atmospheric effects on the cosmic ray total intensity at sea level

1956 ◽  
Vol 4 (6) ◽  
pp. 1479-1495 ◽  
Author(s):  
F. Bachelet ◽  
A. M. Conforto
Keyword(s):  
Sea Level ◽  
Cosmic Ray ◽  
Atmospheric Effects

Response Functions of Cosmic Ray Muon Telescopes at Sea Level and at 60 m.w.e.

1974 ◽  
Vol 52 (11) ◽  
pp. 979-984 ◽  
Author(s):  
R. B. Hicks ◽  
G. Simpson ◽  
T. Mathews
Keyword(s):  
Sea Level ◽  
Cosmic Ray ◽  
Primary Response ◽  
Response Functions ◽  
Theoretical Determination ◽  
Standard Atmosphere ◽  
Latitude Effect ◽  
East West ◽  
Comparison With Experimental Data

A theoretical determination of the primary response of cosmic ray muon telescopes is presented. The calculations take into account successive collisions of an incoming primary nucleon, the distribution in energy of pions and muons at generation, and the decay and energy loss of muons in the standard atmosphere. Values of the primary muon multiplicity are given for telescopes at sea level and at a depth of 60 m.w.e. underground. The response functions obtained are verified by comparison with experimental data on the latitude effect and equatorial east–west effect at sea level. Comparisons are also made with response functions proposed by other workers for telescopes at 60 m.w.e.

ATMOSPHERIC EFFECTS ON COSMIC RAY INTENSITY AT SEA LEVEL

1959 ◽  
Vol 37 (2) ◽  
pp. 85-101 ◽  
Author(s):  
P. M. Mathews
Keyword(s):  
Sea Level ◽  
Cosmic Ray ◽  
Barometric Pressure ◽  
Theoretical Formula ◽  
Atmospheric Effects ◽  
Cosmic Ray Intensity ◽  
Statistical Fluctuations ◽  
Nucleonic Component ◽  
Primary Origin ◽  
First Time

Cosmic ray intensity variations of primary origin and those caused by meteorological changes appear superposed in records obtained from meson counter telescopes and neutron monitors at sea level. The study of either of these types of variation is thus greatly complicated by the presence of the other. In the present work, we have for the first time taken the step of processing the raw data to eliminate primary variations (and the inherent statistical fluctuations) so as to make possible a direct comparison of the remaining variations with the changes in atmospheric variables over the same period. The subsequent analysis confirms the expectation that there are no appreciable atmospheric effects on the intensity of the nucleonic component beyond the well-known effect associated with the sea level barometric pressure B. But in the meson case there is strong evidence that the widely used set of variables H100, T100 (the height and temperature of the 100-mb level) and B is not very suitable for representing atmospheric effects; it seems essential to include a variable representing temperatures in the lower part of the atmosphere, and the set of variables T800 (temperature of the 800-mb layer), H100, and B, with coefficients kT = −.082 ±.008%/°C, kH = −3.04 ±.61%/km, and kB = −.134 ±.004%/mb appears to be the best. The theoretical formula of Dorman (1957), with a barometric coefficient β = −.147 ±.004%/mb and with the term representing the "temperature effect" reduced by a factor.76 ± .03, gives slightly better results. However, the improvement, at least in the case of the data we have analyzed, is too small to justify the great labor involved in using this formula.

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