scholarly journals Limits on Source Distances for the Most Energetic Cosmic Rays

1997 ◽  
Vol 14 (3) ◽  
pp. 258-264 ◽  
Author(s):  
R. Lampard ◽  
R. W. Clay ◽  
B. R. Dawson
Keyword(s):  
Cosmic Rays ◽  
Energy Loss ◽  
Power Law ◽  
Pion Production ◽  
Cosmic Ray ◽  
Source Spectrum ◽  
Energy Losses ◽  
Microwave Background ◽  
Energy Degradation

AbstractThe propagation of the highest energy cosmic rays through the 2·7 K microwave background is considered. Photo-pion production interactions cause energy losses for primary cosmic ray protons which result in significant energy degradation over intergalactic distances. The process of energy loss is discussed and an estimate is made of the average distances travelled for observed cosmic rays with a range of energies, assuming a power law source spectrum. At energies over 1020 eV, the average distances travelled are a few tens of megaparsecs, limiting possible sources to the volume dominated by the supergalactic plane.

scholarly journals Selective Effects in Cosmic Rays Induced by Coulombian Interactions with Finite Temperature Plasmas

1981 ◽  
Vol 94 ◽  
pp. 365-366
Author(s):  
J. Pérez-Peraza ◽  
S. S. Trivedi
Keyword(s):  
Cosmic Rays ◽  
Energy Levels ◽  
Cosmic Ray ◽  
High Energy ◽  
Energy Losses ◽  
Deceleration Rate ◽  
Acceleration Rate ◽  
Charge States ◽  
High Energy Particles

The role of Coulombian energy losses in cosmic ray physics is generally over simplified by using the Bethe-Block formulation which does not depend explicitly on the temperature of the medium. The role of low energy particles is usually neglected, as a result of the over estimation of losses when the temperature of the medium is ignored. A deep analysis of Coulombian losses may raise the importance of these particles in the dynamics of the Galaxy. In fact, the deceleration of these particles is determined by charge interchange processes with the target ions and electrons, which energy dependence is roughly the inverse of ionisation losses. Even high energy particles may be subject to this kind of deceleration if the temperature is very high. The consideration of Coulombian losses through all energy ranges with explicit dependence on the temperature has been discussed by Perez and Lara (1979): a fully ionized medium of hydrogen has been assumed to prevail in most of cosmic ray sources. One kind of the implications is the determination of particle composition. It is claimed that a given kind of ion is preferentially accelerated or depleted depending on whether the acceleration is higher or lower than the deceleration rate at the beginning of the acceleration of thermal material. Species which undergo depletion are accelerated only if their energy is higher than that for which both rates are equated (Ec,E′c and E′c′) in such a way that only those of the hot tails of their thermal distributions are effectively accelerated. These will appear depleted relative to other species which are free accelerated because their deceleration rates at low energies are lower than the acceleration rate. It can be noted in the next figures, that if both rates would not intersect at the beginning of the acceleration, they would not join at higher energies because the acceleration rate grows faster with energy than the deceleration rate. Three arbitrary acceleration rates are used for illustration: Fermi-2nd order (αβW), Betatron or adiabatic heating (αβ2W) and shock wave acceleration (αW), where α, β and W are the efficiency, the particles velocity and the total energy per nucleon respectively. In Fig. 1 it can be seen that this selective acceleration relative to Coulombian losses is defined at different energy levels depending on the kind of acceleration involved. Since the main effect of the temperature on the losses at the beginning of the acceleration is through the local charge states of the ions, the sequence of energy losses among different species is highly assorted. This is translated in a great amount of possibilities of particle enhancements and depletions according to the temperature of the source and the kind of acceleration operating therein. If particles under go acceleration in a fully stripped state, the sequence of losses at all energy levels is such that the heavy elements are depleted in relation with the lighter ones; same is the situation, what-ever the initial charge state, for high energy particles in the range of ionisation. It may be concluded, on basis to the observational enhancement of heavy cosmic rays, that hot regions are not likely sources, and that acceleration initiates from thermal energies. On Fig. 2 it is illustrated the enhancement of Fe over 0 in solar flare conditions, on basis to the charge states as given by Jordan (1969). If α < 2.71 s−1 both elements would be depleted, whereas if α>3.45 s−1 both would be preferentially accelerated.

IONIZATION LOSS BY COSMIC-RAY MU-MESONS IN ARGON

1959 ◽  
Vol 37 (2) ◽  
pp. 189-202 ◽  
Author(s):  
Georges Hall
Keyword(s):  
Experimental Data ◽  
Energy Loss ◽  
Ionization Chamber ◽  
Cosmic Ray ◽  
Statistical Distribution ◽  
Experimental Curve ◽  
Energy Losses ◽  
Ionization Loss ◽  
Electron Collection ◽  
Probable Loss

The ionization of argon by cosmic-ray mu-mesons of minimum specific ionization has been studied by means of a calibrated pressure-ionization chamber using electron collection. Corrections which are shown to be necessary have been applied to the experimental data. The shape of the experimental curve of statistical distribution of energy loss agrees with the theoretically predicted shape, for energy losses greater than the most probable loss (300 kev).

The Extragalactic Flux of Cosmic Rays

1996 ◽  
Vol 13 (2) ◽  
pp. 121-126 ◽  
Author(s):  
R. W. Clay ◽  
A. G. K. Smith
Keyword(s):  
Cosmic Rays ◽  
Magnetic Fields ◽  
Power Law ◽  
Cosmic Ray ◽  
Static Magnetic Fields ◽  
Remarkable Similarity ◽  
Flux Change ◽  
The Galaxy ◽  
Energy Perturbation ◽  
Cosmic Ray Flux

AbstractThe propagation of extragalactic particles within our Galaxy has been modelled. The flux of such particles is below the observed cosmic ray flux at most energies when their power-law spectrum is extrapolated back from the highest energies. Also, we expect that the propagation of extragalactic particles through static magnetic fields in the Galaxy will not result in a flux change to match the flux of particles measured here within the Galaxy. However, if we were to consider the observed cosmic rays to be of Galactic origin, there would be a remarkable similarity between the required Galactic injection flux and the extrapolated extragalactic flux. We consider here whether the scattering of extragalactic particles in the Galaxy together with an associated energy perturbation might be sufficient for the extragalactic beam to result in the production of ‘Galactic’ particles and, hence, essentially all of the observed cosmic rays. This appears to be possible.

scholarly journals Atmospheric Effect on Cosmic Ray Muons at High Cut-Off Rigidity Station

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Abdullrahman Maghrabi ◽  
Mohammed Almutayri
Keyword(s):  
Saudi Arabia ◽  
Cosmic Rays ◽  
Seasonal Variations ◽  
Atmospheric Pressure ◽  
Pion Production ◽  
Cosmic Ray ◽  
Pressure Level ◽  
The Other ◽  
Atmospheric Effect ◽  
Clear Explanation

Cosmic ray data and radiosonde measurements from Riyadh, Saudi Arabia (Rc = 14.4 GV), for the period 2002–2012, were used to study the effect of atmospheric pressure, level of pion production, and temperature at that level, on cosmic ray muons. We found that, even if corrections were made to the detected muons using these three parameters, seasonal variations of the cosmic rays still exist. This suggests that other terrestrial and/or extraterrestrial causes may be considered. The levels of pion production and atmospheric pressure are inversely correlated with the muon rate. On the other hand, the temperature at the pion production level is correlated with muons in spring and winter and inversely correlated in fall and summer. There is no clear explanation for this behavior.

scholarly journals Modulation effect of magnetic corotating trap on 27-day cosmic ray variation in November–December 2014

2019 ◽  
Vol 5 (1) ◽  
pp. 11-13
Author(s):  
Валерий Сдобнов ◽  
Valeriy Sdobnov ◽  
Марина Кравцова ◽  
Marina Kravtsova ◽  
Сергей Олемской ◽  
...  
Keyword(s):  
Energy Loss ◽  
Interplanetary Space ◽  
Intensity Variation ◽  
Cosmic Ray ◽  
Energy Losses ◽  
The Sun ◽  
Modulation Effect ◽  
Neutron Monitors ◽  
Worldwide Network ◽  
Determining Factor

We study the 27-day cosmic-ray (CR) intensity variation occurring in November–December 2014, using ground-based measurements from the worldwide network of neutron monitors and GOES-15 satellites. A determining factor in the considerable difference between amplitudes of the 27-day CR variation in November–December 2014 is shown to be significant changes in energy losses taking place when particles move in regular heliospheric electromagnetic fields. In this period, there was a long-living corotating trap produced by a vast coronal hole in the south of the Sun in interplanetary space. Configuration of this trap induced the energy loss of ~3–20 GeV CRs, due to which ground-based neutron monitors recorded an abnormally large amplitude of the 27-day variation.

The Source Energy Spectrum of Cosmic Rays

2002 ◽  
Vol 19 (2) ◽  
pp. 228-232 ◽  
Author(s):  
R. W. Clay
Keyword(s):  
Energy Spectrum ◽  
Cosmic Rays ◽  
Energy Range ◽  
Power Law ◽  
Lower Energy ◽  
Full Range ◽  
Source Spectrum ◽  
Common Source ◽  
Propagation Effects ◽  
The Relationship

AbstractAn examination is made of the relationship between the observed energy spectrum of cosmic rays and the averaged spectrum of the cosmic rays at their sources. These spectra differ greatly, due to propagation effects. A form of the source spectrum is deduced which is a rather featureless power law over the full range of observations from 1010 eV to 1020 eV. We suggest that this lack of features is indicative of a common source for all cosmic rays over the full energy range, as opposed to lower energy Galactic and higher energy intergalactic components such as is often suggested.

scholarly journals The gluon condensation in high energy cosmic rays

2018 ◽  
Vol 27 (09) ◽  
pp. 1850073 ◽  
Author(s):  
Wei Zhu ◽  
Jiangshan Lan ◽  
Jianhong Ruan
Keyword(s):  
Cosmic Rays ◽  
Power Law ◽  
Cosmic Ray ◽  
High Energy ◽  
High Energy Cosmic Rays ◽  
Accelerated Protons

The gluon condensation (GC)-effects in high energy cosmic rays are investigated. After a brief review of the GC, several examples including gamma-, electron- and positron-spectra in a broad [Formula: see text] region can be explained by the GC-effects. We find that the GC may break the power-law of the cosmic ray spectra if the energy of accelerated protons exceeds the GC-threshold. The GC is a new phenomenon that is not yet known, it provides a new window to understand the high energy cosmic ray spectra.

scholarly journals Are Stellar Flares and the Galactic Cosmic Rays Related?

1981 ◽  
Vol 94 ◽  
pp. 109-110 ◽  
Author(s):  
Richard I. Epstein
Keyword(s):  
Cosmic Rays ◽  
Energy Dependence ◽  
Nuclear Reactions ◽  
Cosmic Ray ◽  
Galactic Cosmic Rays ◽  
Energy Losses ◽  
Two Stage ◽  
Stage Models ◽  
Stellar Flares ◽  
Stage Process

It has been suggested that the Galactic cosmic rays may be accelerated by a two stage process in which one process, such as stellar flares, inject non-relativistic, super-thermal particles which are subsequently boosted to cosmic ray energies by some other mechanism, perhaps related to supernovae (eg. Cassé and Goret, 1978). Two-stage models in which the injection and re-acceleration processes are uncorrelated are apparently untenable because they cannot fit the observed energy dependence of the LiBeBN/CNO ratio. Here it is shown that additional contraints derived by considering the energy losses and nuclear reactions suffered by the super-thermal particles prior to their re-acceleration severely restrict other types of two-stage models.

scholarly journals Modulation effect of magnetic corotating trap on 27-day cosmic ray variation in November–December 2014

2019 ◽  
Vol 5 (1) ◽  
pp. 13-16
Author(s):  
Валерий Сдобнов ◽  
Valeriy Sdobnov ◽  
Марина Кравцова ◽  
Marina Kravtsova ◽  
Сергей Олемской ◽  
...  
Keyword(s):  
Energy Loss ◽  
Interplanetary Space ◽  
Intensity Variation ◽  
Cosmic Ray ◽  
Energy Losses ◽  
The Sun ◽  
Modulation Effect ◽  
Neutron Monitors ◽  
Worldwide Network ◽  
Determining Factor

We study the 27-day cosmic-ray (CR) intensity variation occurring in November–December 2014, using ground-based measurements from the worldwide network of neutron monitors and GOES-15 satellites. A determining factor in the considerable difference between amplitudes of the 27-day CR variation in November–December 2014 is shown to be significant changes in energy losses taking place when particles move in regular heliospheric electromagnetic fields. In this period, there was a long-living corotating trap produced by a vast coronal hole in the south of the Sun in interplanetary space. Configuration of this trap induced the energy loss of ~3–20 GeV CRs, due to which ground-based neutron monitors recorded an abnormally large amplitude of the 27-day variation.

The momentum spectrum of cosmic rays at a depth of 38 metres water equivalent underground

1959 ◽  
Vol 253 (1273) ◽  
pp. 163-176 ◽  
Keyword(s):  
Cosmic Rays ◽  
Energy Loss ◽  
Direct Determination ◽  
Cosmic Ray ◽  
Ground Level ◽  
Momentum Spectrum ◽  
Collision Process ◽  
Momentum Range ◽  
Level Spectrum

A direct determination has been made of the cosmic ray spectrum underground at a depth of 38 m. w. e. under Castle Rock, Nottingham. The spectrum is based on measurements of 1010 particles traversing a magnetic spectrograph having a maximum detectable momentum of 8 GeV/ c . By comparing this spectrum with the ground-level spectrum the energy loss of fast μ -mesons in penetrating the 38 m. w. e. of rock has been determined. It is shown that the energy loss for μ -mesons in the momentum range 7 to 15 GeV/ c is as expected by theory, the collision process being responsible for most of the loss.

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