scholarly journals CR-39 Plastic Track Detector Experiment for Measurement of Charge Composition of Primary Cosmic Rays

1981 ◽  
Vol 94 ◽  
pp. 37-38
Author(s):  
Y. V. Rao ◽  
A. Davis ◽  
M. P. Hagan ◽  
R. C. Filz
Keyword(s):  
Cosmic Rays ◽  
Cosmic Ray ◽  
Track Detector ◽  
Energy Spectra ◽  
Charge Composition ◽  
Significant Information ◽  
Residual Atmosphere ◽  
New Type ◽  
Air Force Base ◽  
Primary Cosmic Rays

A study of the relative abundances and energy spectra of heavy cosmic rays and isotopic composition in the region of Fe peak can yield significant information concerning their origin, acceleration and interstellar propagation. In recent years solid state nuclear track detectors have been employed extensively to study heavy primary cosmic rays. Plastic track detectors necessarily have large geometric factors for heavy primaries, and a continuous sensitivity for the duration of an extended exposure. A balloon-borne experiment consisting of 1 m2 passive detector array has been designed in order to obtain charge and energy spectra of primary cosmic rays in the region of Fe peak. Included in the array is a new type of nuclear-track-recording plastic, a polymer made from the monomer allyl diglycol carbonate (commercially known as CR-39). The stack was built as a set of nine modules. Three types of stack assembly was adopted for these modules: one consisting of ‘pure’ CR-39 plastic track detector: the next one, a composite assembly of CR-39 with three layers of 600 micron thick nuclear emulsions: and the last one with CR-39 and Lexan Polycarbonate. The payload was flown successfully in June 1979 from Eielson Air Force Base, Alaska. The flight was aloft for 3 hours 30 min at an average ceiling of 3 gm/cm2 of residual atmosphere. An attempt to stabilize and orient the payload utilizing a biaxial magnetometer combined with and electrical rotator was unsuccessful. The failure to orient the payload in a stable position would prevent us from determining the true direction of each cosmic ray particle and trace it backwards through the earth's magnetic field using a computer tracing program. Recovery of the payload was routine and all materials were in perfect condition.

Charge and energy spectra of cosmic-ray nuclei with Z = 10–28

1968 ◽  
Vol 46 (10) ◽  
pp. S588-S592 ◽  
Author(s):  
V. S. Bhatia ◽  
V. S. Chohan ◽  
S. D. Pabbi ◽  
S. Biswas
Keyword(s):  
Cosmic Rays ◽  
Nuclear Charge ◽  
Cosmic Ray ◽  
Energy Spectra ◽  
Charge Composition ◽  
Improved Method ◽  
Residual Atmosphere ◽  
Primary Ionization ◽  
Charge Determination

An improved method of charge determination of heavy primary cosmic rays of nuclear charge Z = 10–28 has been obtained by measuring the Fowler–Perkins parameter in less-sensitive G-2 and G-0 emulsions for the determination of the primary ionization. It is found that reliable measurements of the primary ionization can be made for ionizations as high as ~1 000 times minimum. The average errors in the charge determinations by this method were found to be about 0.5, 0.7, and 1.0 unit of charge for H1 (Z = 10–15), H2 (Z = 16–19), and H3 (Z = 20–30) groups of nuclei, respectively. This method has been applied to the study of the H1, H2, and H3 groups of nuclei in an emulsion stack exposed over Fort Churchill, Canada, on June 18, 1963 at 4.3 g cm−2 of residual atmosphere for 11.1 h. The results are based on an analysis of 340 nuclei with [Formula: see text]. The charge composition and relative abundances of the H1, H2, and H3 nuclei were obtained. The differential energy spectra of the H1, H2, H3, and [Formula: see text] groups of nuclei were determined in the energy interval 250–1 000 MeV/nucleon and integral fluxes for energy > 1 000 MeV/nucleon.

The composition of low-energy cosmic rays in 1965

1968 ◽  
Vol 46 (10) ◽  
pp. S539-S543 ◽  
Author(s):  
D. E. Hagge ◽  
V. K. Balasubrahmanyan ◽  
F. B. McDonald
Keyword(s):  
Cosmic Rays ◽  
Energy Range ◽  
Cosmic Ray ◽  
Low Energy ◽  
Oxygen Flux ◽  
Energy Spectra ◽  
Solar Modulation ◽  
Charge Composition ◽  
Specific Component ◽  
Relative Abundances

Primary cosmic-ray energy spectra and charge composition have been measured during the 1965 period of solar modulation minimum. A dE/dx vs. E type of scintillator–photomultiplier detector on board the eccentric-orbiting NASA spacecraft OGO-I was used. The charge composition was measured through neon over an energy range of 25 to 200 MeV/nucleon, depending upon the specific component. The spectra for all groups are nearly flat during this time, with the oxygen flux at about 0.005 nucleus/(M2-sr-s-MeV/nucleon). The relative abundances found are Li, 0.27; Be, 0.11; B, 0.37; C, 1.20; N, 0.30; O 1.00; F, [Formula: see text]; Ne, 0 12 An L/M ratio of 0.30 ± 0.06 is found.

A reevaluation of the atmospheric pressure dependence of secondary cosmic-ray neutrons in the context of Cosmic-Ray Neutron Sensing

2021 ◽  
Author(s):  
Jannis Weimar ◽  
Paul Schattan ◽  
Martin Schrön ◽  
Markus Köhli ◽  
Rebecca Gugerli ◽  
...  
Keyword(s):  
Cosmic Rays ◽  
Hydrogen Content ◽  
Atmospheric Pressure ◽  
Cosmic Ray ◽  
Galactic Cosmic Rays ◽  
Atmospheric Air ◽  
Neutron Intensity ◽  
The Earth ◽  
Wide Range ◽  
Primary Cosmic Rays

<p><span>Secondary cosmic-ray neutrons may be effectively used as a proxy for environmental hydrogen content at the hectare scale. These neutrons are generated mostly in the upper layers of the atmosphere within particle showers induced by galactic cosmic rays and other secondary particles. Below 15 km altitude their intensity declines as primary cosmic rays become less abundant and the generated neutrons are attenuated by the atmospheric air. At the earth surface, the intensity of secondary cosmic-ray neutrons heavily depends on their attenuation within the atmosphere, i.e. the amount of air the neutrons and their precursors pass through. Local atmospheric pressure measurements present an effective means to account for the varying neutron attenuation potential of the atmospheric air column above the neutron sensor. Pressure variations possess the second largest impact on the above-ground epithermal neutron intensity. Thus, using epithermal neutrons to infer environmental hydrogen content requires precise knowledge on how to correct for atmospheric pressure changes.</span></p><p><span>We conducted several short-term field experiments in saturated environments and at different altitudes, i.e. different pressure states to observe the neutron intensity pressure relation over a wide range of pressure values. Moreover, we used long-term measurements above glaciers in order to monitor the local dependence of neutron intensities and pressure in a pressure range typically found in Cosmic-Ray Neutron Sensing. The results are presented along with a broad Monte Carlo simulation campaign using MCNP 6. In these simulations, primary cosmic rays are released above the earth atmosphere at different cut-off rigidities capturing the whole evolution of cosmic-ray neutrons from generation to attenuation and annihilation. The simulated and experimentally derived pressure relation of cosmic-ray neutrons is compared to those of similar studies and assessed in the light of an appropriate atmospheric pressure correction for Cosmic-Ray Neutron Sensing.</span></p>

A New Determination of Muon Directional Coupling Coefficients

1968 ◽  
Vol 1 (4) ◽  
pp. 154-157
Author(s):  
D. J. Cooke ◽  
A. G. Fenton
Keyword(s):  
Cosmic Rays ◽  
Solar System ◽  
Cosmic Ray ◽  
Accurate Information ◽  
Coupling Coefficients ◽  
The Earth ◽  
Directional Coupling ◽  
Cosmic Ray Flux ◽  
Primary Cosmic Rays

Primary cosmic rays passing through the solar system carry with them valuable information about solar and astrophysical phenomena in the form of intensity and spectral variations. In order that this information be efficiently extracted from observations of the directional cosmic-ray flux at the surface of the Earth, it is essential to have accurate information available to enable the relating of the observed secondary cosmic-ray directions of motion and intensity to those outside the range of the disturbing terrestrial influences.

The effects of the nature of matter traversed by cosmic rays on their composition and energy spectrum

1968 ◽  
Vol 46 (10) ◽  
pp. S512-S514
Author(s):  
M. V. K. Apparao ◽  
S. Ramadurai
Keyword(s):  
Energy Spectrum ◽  
Cosmic Rays ◽  
Neutral Hydrogen ◽  
Cosmic Ray ◽  
The State ◽  
Energy Spectra ◽  
Ionization Loss ◽  
Usual Assumption ◽  
Considerable Portion ◽  
Nature Of Matter

The effects of the state of ionization of the matter traversed by cosmic rays, and those due to the presence of helium in it, have been studied. The amount of matter traversed by cosmic rays expressed in g/cm2 deduced by the usual assumption that the matter traversed is all neutral hydrogen can be erroneous. The presence of helium increases this value, and a considerable portion of the matter is helium. The ionized (partial) nature of the matter increases the ionization loss of cosmic-ray nuclei. The effect of this on energy spectra has been demonstrated.

scholarly journals Hysteresis of Primary Cosmic Rays Associated with Forbush Decreases

1976 ◽  
Vol 29 (2) ◽  
pp. 89
Author(s):  
RS Rajan
Keyword(s):  
Regression Analysis ◽  
Cosmic Rays ◽  
Cosmic Ray ◽  
Differential Modulation ◽  
Forbush Decreases ◽  
Primary Cosmic Rays

Regression analysis of primary cosmic ray intensities during Forbush decreases indicates the existence of a differential modulation between high and low rigidity primaries.

Particle Acceleration in the Disk-Halo System

1991 ◽  
Vol 144 ◽  
pp. 377-386
Author(s):  
Reinhard Schlickeiser
Keyword(s):  
Particle Acceleration ◽  
Cosmic Rays ◽  
Cosmic Ray ◽  
Energy Spectra ◽  
Galactic Wind ◽  
Γ Rays ◽  
Γ Ray

The recent observations of the nonthermal properties of the halo of our Galaxy at radio and γ-ray wavelengths are summarized. Radio and γ-ray data show a similar spectral flattening with Galactic height towards the anticenter direction, which is interpreted as a cosmic-ray effect. Several theoretical explanations for the flattening of the energy spectra of the radiating cosmic-ray electrons (in the radio) and nucleons (in γ-rays) are reviewed including propagation of cosmic rays in an accelerating Galactic wind and the presence of cosmic-ray sources with flat energy spectra in the halo.

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