The connection between the mean and local coefficients of diffusion for cosmic rays

1978 ◽  
Vol 58 (2) ◽  
pp. 341-345 ◽  
Author(s):  
V. S. Ptuskin
Keyword(s):  
Cosmic Rays ◽  
Local Coefficients ◽  
The Mean

scholarly journals The highest-energy cosmic-rays – the past, the present and the future

2019 ◽  
Vol 210 ◽  
pp. 00001
Author(s):  
Alan Watson
Keyword(s):  
Energy Spectrum ◽  
Cosmic Rays ◽  
Mass Distribution ◽  
Mass Composition ◽  
Future Prospects ◽  
Telescope Array ◽  
Hadronic Interactions ◽  
The Past ◽  
Shower Maximum ◽  
The Mean

The greater part of this paper is concerned with a historical discussion of the development of the search for the origins of the highest-energy cosmic-rays together with a few remarks about future prospects.Additionally, in section 6, the situation with regard to the mass composition and energy spectrum at the highest energies is discussed. It is shown that the change of the depth of shower maximum with energy above 1 EeV, measured using the Telescope Array, is in striking agreement with similar results from the Auger Observatory. This implies that either the mean mass of cosmic rays is becoming heavier above ~4 EeV or that there is a change in details of the hadronic interactions in a manner such that protons masquerade as heavier nuclei. A long-standing controversy is thus resolved: the belief that pure protons dominate the mass distribution at the highest energies is no longer tenable.

scholarly journals Possible heliogeophysical effects on human physiological state

2008 ◽  
Vol 4 (S257) ◽  
pp. 65-67 ◽  
Author(s):  
Svetla Dimitrova
Keyword(s):  
Blood Pressure ◽  
Cosmic Rays ◽  
Healthy Volunteers ◽  
Geomagnetic Activity ◽  
Pulse Pressure ◽  
Pressure Pulse ◽  
Physiological State ◽  
Activity Increase ◽  
Hourly Data ◽  
The Mean

AbstractA group of 86 healthy volunteers was examined in periods of high solar and geomagnetic activity. In this study hourly Dst-index values and hourly data about intensity of cosmic rays were used. Results revealed statistically significant increments for the mean systolic and diastolic blood pressure, pulse pressure and subjective psycho-physiological complaints of the group with geomagnetic activity increase and cosmic rays intensity decrease.

Energy Changes of Cosmic Rays

1978 ◽  
Vol 3 (3) ◽  
pp. 233-234
Author(s):  
L. J. Gleeson ◽  
G. M. Webb
Keyword(s):  
Cosmic Rays ◽  
Solar System ◽  
Density Gradient ◽  
Cosmic Ray ◽  
Integral Form ◽  
Rate Of Change ◽  
Number Density ◽  
Ray Density ◽  
The Mean

Recently (Gleeson (1972), Quenby (1973), Gleeson and Webb (1974, 1978)) it has been shown that the mean rate of change of momentum of cosmic rays reckoned for a volume fixed in the solar system iswhere G = (1/Up)(∂Up/∂r)si the cosmic-ray density gradient with Up, the differential number density with respect to momentum p at position r. (cf also the integral form of (1) by Jokipii and Parker 1967).

scholarly journals Influence of the Schwabe/Hale solar cycles on climate change during the Maunder Minimum

2009 ◽  
Vol 5 (S264) ◽  
pp. 427-433 ◽  
Author(s):  
Hiroko Miyahara ◽  
Yusuke Yokoyama ◽  
Yasuhiko T. Yamaguchi
Keyword(s):  
Climate Change ◽  
Solar Activity ◽  
Cosmic Rays ◽  
Cosmic Ray ◽  
Maunder Minimum ◽  
Activity Level ◽  
Solar Cycles ◽  
Early Medieval ◽  
Maximum Period ◽  
The Mean

AbstractWe have examined the variation of carbon-14 content in annual tree rings, and investigated the transitions of the characteristics of the Schwabe/Hale (11-year/22-year) solar and cosmic-ray cycles during the last 1200 years, focusing mainly on the Maunder and Spoerer minima and the early Medieval Maximum Period. It has been revealed that the mean length of the Schwabe/Hale cycles changes associated with the centennial-scale variation of solar activity level. The mean length of Schwabe cycle had been ~14 years during the Maunder Minimum, while it was ~9 years during the early Medieval Maximum Period. We have also found that climate proxy record shows cyclic variations similar to stretching/shortening Schwabe/Hale solar cycles in time, suggesting that both Schwabe and Hale solar cycles are playing important role in climate change. In this paper, we review the nature of Schwabe and Hale cycles of solar activity and cosmic-ray flux during the Maunder Minimum and their possible influence on climate change. We suggest that the Hale cycle of cosmic rays are amplified during the grand solar minima and thus the influence of cosmic rays on climate change is prominently recognizable during such periods.

scholarly journals The seasonal variations of cosmic-ray intensity and temperature of the atmosphere

1941 ◽  
Vol 177 (969) ◽  
pp. 204-216 ◽  
Keyword(s):  
Cosmic Rays ◽  
Cosmic Ray ◽  
The United States ◽  
Careful Examination ◽  
Cosmic Ray Intensity ◽  
Mean Temperature ◽  
Atmospheric Data ◽  
The Mean ◽  
Additional Support ◽  
Autumn And Winter

A careful examination of the upper atmospheric data for Europe and the United States indicates that the mean temperature of the upper atmosphere in spring differs from that in summer more than from that in winter. The magnitude of the second difference as defined by (1) depends on the height of the atmosphere which is considered and is a maximum at a height of about 6 km. and changes sign at heights above 12 km. (figure 1). This lag in the warming of the atmosphere in spring is found to be paralleled by a lag in the diminution of intensity of the cosmic-rays. A similar phenomenon is found in autumn. The cooling of the atmosphere as a whole is found to be less between summer and autumn than between autumn and winter, though the effect is markedly less definite than in spring. The cosmic-ray variations are found to be correlated more closely with the mean temperature of the atmosphere up to 16 km. than with the temperature near the ground. This provides additional support for the theory of Blackett that the temperature variation of penetrating cosmic-rays is related to the instability of the mesotron. The temperature coefficient of the cosmic-rays as deduced from the seasonal data is found to be 0.18 %/° C, and this is in rough agreement with the prediction of the theory.

Galactic Cosmic Rays in a Finite Solar Cavity

1977 ◽  
Vol 3 (2) ◽  
pp. 162-164 ◽  
Author(s):  
G. M. Webb ◽  
L. J. Gleeson
Keyword(s):  
Distribution Function ◽  
Steady State ◽  
Cosmic Rays ◽  
Spherical Symmetry ◽  
Heliocentric Distance ◽  
Galactic Cosmic Rays ◽  
Physical Parameters ◽  
The Mean

In this paper we model mathematically the propagation of galactic cosmic-rays in the solar cavity and study the effects of changing the physical parameters; in particular the radius of the cavity. We assume spherical symmetry with heliocentric distance r, momentum p and work in terms of F0(r, p) the mean distribution function with respect to momentum; it is related to JT the mean differential intensity w.r.t. energy by JT = p2F0. The boundary is at r = rb beyond which the galactic spectrum prevails; there is free escape of particles incident on rb from within, and the distribution is steady state.

Electron component in primary cosmic rays. II. Theory

1968 ◽  
Vol 46 (10) ◽  
pp. S533-S535
Author(s):  
A. Danjo ◽  
S. Hayakawa ◽  
F. Makino ◽  
H. Obayashi
Keyword(s):  
Cosmic Rays ◽  
Scattering Length ◽  
Cosmic Ray ◽  
Critical Energy ◽  
Galactic Cosmic Rays ◽  
Particle Diffusion ◽  
Electron Component ◽  
Positron Flux ◽  
Energy Formula ◽  
The Mean

The energy spectrum of cosmic-ray electrons can be represented by a power law with a single exponent between 3 and 50 GeV, and a break in the spectrum due to the energy loss of electrons could appear at about 50 GeV or higher. It is necessary to reconcile this high value of the critical energy [Formula: see text] with the effective thickness of matter traversed [Formula: see text] as estimated from the positron flux) and with the small amplitude of anisotropy [Formula: see text]. Hence rather severe conditions are imposed on the properties of the region in which cosmic rays are stored. We have carried out an investigation of the two-component model for storing galactic cosmic rays, which consists of disk and halo components. Assuming the intensity ratio (η) of the halo to the disk components to be nearly unity, one can assign parameters explaining various properties of cosmic rays consistently. For the case of a vanishing halo component (η = 0), the mean scattering length for particle diffusion becomes about 1018 cm.

EVAPORATION NEUTRONS FROM COSMIC RAY NUCLEAR INTERACTIONS IN VARIOUS ELEMENTS

1956 ◽  
Vol 34 (3) ◽  
pp. 288-303 ◽  
Author(s):  
K. W. Geiger
Keyword(s):  
Cosmic Rays ◽  
Cross Section ◽  
Cross Sections ◽  
Boron Trifluoride ◽  
Cosmic Ray ◽  
Atomic Weight ◽  
Nuclear Interactions ◽  
The Mean ◽  
Neutron Multiplicities ◽  
Interaction Cross Sections

Production of evaporation neutrons from nuclear interactions by cosmic rays is investigated in C, Al, Fe, Cu, Pb, and Bi. Boron trifluoride counters in a paraffin moderator in which the element under study is placed serve to detect the evaporation neutrons. A cosmic ray telescope allows the consideration of ionizing neutron-producing particles separately and it is found that of the total neutrons 14.6% are produced by ionizing particles. The mean neutron multiplicities are worked out and they show an increase with the two-thirds power of the atomic weight of the element in which the interactions take place. Also, the rate of interactions is calculated and this gives the relative interaction cross-sections which are found to increase slightly more with atomic weight than expected if the cross-section is geometric. An estimate of the intensity of the N-component is made and discussed in connection with measurements published by other authors.

scholarly journals Solar energetic particles and galactic cosmic rays over millions of years as inferred from data on cosmogenic 26Al in lunar samples

2018 ◽  
Vol 618 ◽  
pp. A96 ◽  
Author(s):  
S. Poluianov ◽  
G. A. Kovaltsov ◽  
I. G. Usoskin
Keyword(s):  
Cosmic Rays ◽  
Solar Physics ◽  
A Priori ◽  
Lunar Soil ◽  
Galactic Cosmic Rays ◽  
Energetic Particles ◽  
Solar Energetic Particles ◽  
Solar Modulation ◽  
Lunar Samples ◽  
The Mean

Aims. Lunar soil and rocks are not protected by a magnetic field or an atmosphere and are continuously irradiated by energetic particles that can produce cosmogenic radioisotopes directly inside rocks at different depths depending on the particle’s energy. This allows the mean fluxes of solar and galactic cosmic rays to be assessed on the very long timescales of millions of years. Methods. Here we show that lunar rocks can serve as a very good particle integral spectrometer in the energy range 20–80 MeV. We have developed a new method based on precise modeling, that is applied to measurements of 26Al (half-life ≈0.7 megayears) in lunar samples from the Apollo mission, and present the first direct reconstruction (i.e., without any a priori assumptions) of the mean energy spectrum of solar and galactic energetic particles over a million of years. Results. We show that the reconstructed spectrum of solar energetic particles is totally consistent with that over the last decades, despite the very different levels of solar modulation of galactic cosmic rays (ϕ = 496 ± 40 MV over a million years versus (ϕ = 660 ± 20 MV for the modern epoch). We also estimated the occurrence probability of extreme solar events and argue that no events with the F(>30 MeV) fluence exceeding 5×1010 and 1011 cm−2 are expected on timescales of a thousand and million years, respectively. Conclusions. We conclude that the mean flux of solar energetic particles hardly depends on the level of solar activity, in contrast to the solar modulation of galactic cosmic rays. This puts new observational constraints on solar physics and becomes important for assessing radiation hazards for the planned space missions.

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