The path-length distribution for galactic cosmic-ray propagation - an energy-dependent depletion of short path lengths

1984 ◽  
Vol 280 ◽  
pp. L13 ◽  
Author(s):  
M. Garcia-Munoz ◽  
T. G. Guzik ◽  
J. A. Simpson ◽  
J. P. Wefel
Keyword(s):  
Short Path ◽  
Path Length ◽  
Length Distribution ◽  
Cosmic Ray ◽  
Path Lengths ◽  
Energy Dependent ◽  
Galactic Cosmic Ray

scholarly journals Estimation of Length of Node-to-Node Paths Distribution in the Global Network

2020 ◽  
Vol 27 (1) ◽  
pp. 6-21
Author(s):  
Alexandra I. Kononova ◽  
Alexey V. Gorodilov
Keyword(s):  
Path Length ◽  
Length Distribution ◽  
Global Network ◽  
Estimation Of Parameters ◽  
Measurement Results ◽  
Distribution Parameters ◽  
Path Lengths ◽  
Skewness And Kurtosis ◽  
Selection Of

The experiment aimed at finding a distribution of path lengths between nodes in the global network and an estimation of parameters of that distribution is described.In particular, the method of measurement of path length with traceroute utility of the GNU/Linux system and limitations on the selection of nodes imposed by traceroute are described. ‘e measurement results are provided and high values of skewness and kurtosis for all resulting distributions are noted. Simulation model of this experiment was developed to test the experiment validity in the determination of distribution parameters in the global network. This model is also described. It is shown that high values of skewness and kurtosis of the measured distributions are not the result of the measurement technique, therefore the global network could not be described by the Barabasi–Albert ´ model. Several most viable hypotheses explaining diffierences in skewness and kurtosis of experimentally obtained pathlength distribution estimations and values derived from the Barabasi–Albert model are listed. Results of diffierent hypotheses ´ simulations are provided. It is shown that the most fitting hypothesis is that definitive influence on skewness and kurtosis of path-length distribution estimations is caused by the quasi pre-fractal structure of the global network.

scholarly journals Interpretation of cosmic ray composition - The path length distribution

1981 ◽  
Vol 247 ◽  
pp. 362 ◽  
Author(s):  
R. J. Protheroe ◽  
J. F. Ormes ◽  
G. M. Comstock
Keyword(s):  
Path Length ◽  
Length Distribution ◽  
Cosmic Ray

Cosmic-ray propagation in the Galaxy and in the heliosphere - The path-length distribution at low energy

1987 ◽  
Vol 64 ◽  
pp. 269 ◽  
Author(s):  
M. Garcia-Munoz ◽  
J. A. Simpson ◽  
T. G. Guzik ◽  
J. P. Wefel ◽  
S. H. Margolis
Keyword(s):  
Path Length ◽  
Length Distribution ◽  
Cosmic Ray ◽  
Low Energy ◽  
The Galaxy

Calcium Fluoride Micro Cells for Synchrotron Radiation Circular Dichroism Spectroscopy

2005 ◽  
Vol 59 (9) ◽  
pp. 1109-1113 ◽  
Author(s):  
F. Wien ◽  
B. A. Wallace
Keyword(s):  
Circular Dichroism ◽  
Synchrotron Radiation ◽  
Data Collection ◽  
Calcium Fluoride ◽  
Short Path ◽  
Path Length ◽  
Small Sample ◽  
Path Lengths ◽  
Fixed Path ◽  
Circular Dichroïsm

Demountable calcium fluoride micro cells have been developed for use in synchrotron radiation circular dichroism (SRCD) spectroscopy. They have the advantages that they require only very small sample volumes (as low as 1 microliter) and have short path lengths (as small as 2 micrometers). Highly reproducible spectra can be obtained in consecutive loadings with these spacer-free, fixed path length cells, which enable low wavelength data collection.

scholarly journals On the size distribution of ice-supersaturated regions in the upper troposphere and lowermost stratosphere

2000 ◽  
Vol 18 (4) ◽  
pp. 499-504 ◽  
Author(s):  
K. Gierens ◽  
P. Spichtinger
Keyword(s):  
Size Distribution ◽  
Path Length ◽  
Length Distribution ◽  
Atmospheric Composition ◽  
Trial And Error ◽  
Upper Troposphere ◽  
Composition And Structure ◽  
The Mean ◽  
Path Lengths ◽  
Set Up

Abstract. In order to determine typical sizes of ice-supersaturated regions (ISSRs) in the upper troposphere and lowermost stratosphere we set up the frequency distribution of path lengths flown by MOZAIC aircraft within ISSRs. The mean path length is about 150 km with a standard deviation of 250 km. We analyse the influence of a selection bias (viz. that large ISSRs are more often crossed by aircraft than small ones) on the obtained path length statistics and derive a mathematical equation that relates the path length distribution to the underlying size distribution of ISSRs, assuming that they have circular shape. We solve the equation (by trial and error) and test the result using numerical simulations. Surprisingly, we find that there may be many more very small ISSRs than apparent from the data such that the true mean diameter of the ISSRs may be of the order a few kilometres only. The relevance of the result is discussed and dedicated research flights to measure the true extension of ISSRs are recommended.Key words: Atmospheric composition and structure (troposphere · composition and chemistry; general)

scholarly journals The theory of cosmic ray scattering on pre-existing MHD modes meets data

2021 ◽  
Vol 502 (4) ◽  
pp. 5821-5838
Author(s):  
Ottavio Fornieri ◽  
Daniele Gaggero ◽  
Silvio Sergio Cerri ◽  
Pedro De La Torre Luque ◽  
Stefano Gabici
Keyword(s):  
Diffusion Coefficients ◽  
Galactic Halo ◽  
Dominant Role ◽  
Cosmic Ray ◽  
High Energy ◽  
Scattering Rate ◽  
Equilibrium Spectrum ◽  
Galactic Cosmic Ray ◽  
Comprehensive Study ◽  
Ray Scattering

ABSTRACT We present a comprehensive study about the phenomenological implications of the theory describing Galactic cosmic ray scattering on to magnetosonic and Alfvénic fluctuations in the GeV−PeV domain. We compute a set of diffusion coefficients from first principles, for different values of the Alfvénic Mach number and other relevant parameters associated with both the Galactic halo and the extended disc, taking into account the different damping mechanisms of turbulent fluctuations acting in these environments. We confirm that the scattering rate associated with Alfvénic turbulence is highly suppressed if the anisotropy of the cascade is taken into account. On the other hand, we highlight that magnetosonic modes play a dominant role in Galactic confinement of cosmic rays up to PeV energies. We implement the diffusion coefficients in the numerical framework of the dragon code, and simulate the equilibrium spectrum of different primary and secondary cosmic ray species. We show that, for reasonable choices of the parameters under consideration, all primary and secondary fluxes at high energy (above a rigidity of $\simeq 200 \, \mathrm{GV}$) are correctly reproduced within our framework, in both normalization and slope.

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