Students' Calculation of Cosmic Ray Trajectories

John D. French; William H. Lamb; Philip J. Young

doi:10.1119/1.1976725

Comparison and Time Evolution of the Geomagnetic Cutoff at the ISS Position: Internal vs External Earth’s Magnetic Field Models

Proceedings of the International Astronomical Union ◽

10.1017/s1743921317009863 ◽

2017 ◽

Vol 13 (S335) ◽

pp. 105-108

Author(s):

Matteo J. Boschini ◽

Stefano Della Torre ◽

Massimo Gervasi ◽

Davide Grandi ◽

Giuseppe La Vacca ◽

...

Keyword(s):

Magnetic Field ◽

Solar Activity ◽

Large Fraction ◽

Cosmic Ray ◽

High Solar Activity ◽

Earth’S Magnetic Field ◽

Magnetic Field Data ◽

Geomagnetic Cutoff ◽

Earth's Magnetic Field ◽

Ray Trajectories

AbstractOur back-tracing code (GeoMagSphere) reconstructs the cosmic ray trajectories inside the Earth’s magnetosphere. GeoMagSphere gets the incoming directions of particles entering the magnetopause and disentangles primary from secondary particles (produced in atmosphere) or even particles trapped inside the Earth’s magnetic field. The separation of these particle families allows us to evaluate the geomagnetic rigidity cutoff. The model can be used considering the internal symmetric (IGRF-12) magnetic field only, or adding the asymmetric external one (Tsyganenko models: T89, T96 or TS05). A quantitative comparison among these models is presented for quiet (solar pressure Pdyn < 4 nPa) and disturbed (Pdyn > 4 nPa) periods of solar activity, as well as during solar events like flares, CMEs. In this analysis we focused our attention on magnetic field data in magnetosphere, from Cluster, and simulated cosmic rays for a generic detector on the ISS as for example AMS-02. We found that high solar activity periods, like a large fraction of the period covering years 2011-2015, are better described using IGRF+TS05 model. Results, i.e. the average vertical rigidity cutoff at the ISS orbit, are shown in geographic maps of 2° × 2° cells.

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A STUDY OF VERTICALLY INCIDENT COSMIC-RAY TRAJECTORIES USING SIXTH- DEGREE SIMULATIONS OF THE GEOMAGNETIC FIELD

10.21236/ad0623632 ◽

1965 ◽

Cited By ~ 13

Author(s):

M. A. Shea ◽

D. F. Smart ◽

K. G. McCracken

Keyword(s):

Geomagnetic Field ◽

Cosmic Ray ◽

Ray Trajectories

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Cosmic-ray anisotropy in the north–south direction

Canadian Journal of Physics ◽

10.1139/p68-363 ◽

1968 ◽

Vol 46 (10) ◽

pp. S835-S838

Author(s):

K. Murakami ◽

S. Kudo

Keyword(s):

Solar Rotation ◽

Cosmic Ray ◽

Phase Changes ◽

The Arctic ◽

Intensity Difference ◽

Rapid Phase ◽

The North ◽

The Difference ◽

Ray Trajectories ◽

The Antarctic

For the study of a cosmic-ray anisotropy in the north–south direction, the day-to-day variation of the difference (N–S) of cosmic-ray neutron intensities between the arctic and the antarctic was examined with respect to solar rotations. Harmonic analysis on the variation of the intensity difference shows the existence of a recurrent variation with half the period of a solar rotation. Such a recurrent variation is closely connected with the rapid phase changes of the cosmic-ray diurnal variation during a solar rotation. Regarding the sectored structure of solar wind reported by Wilcox and Ness, the intensity difference (N–S) increases when the earth is passing near a boundary from the (+) sector into the (−) sector, while it decreases near the other boundary. This N–S anisotropy of cosmic rays seems to be caused by the transitional change of cosmic-ray trajectories near the sector boundary and by the spatial distribution of cosmic-ray flux.

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