Experimental Determination of Geomagnetically Trapped Energetic Heavy Ion Fluxes

Spjeldvik, W. N.; Fritz, T. A.

doi:10.1007/978-94-009-7105-9_14

Cited by 13 publications

(11 citation statements)

References 76 publications

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“…In addition, for creation of a sufficiently complete dataset of He nuclei fluxes in the ERB, we had to combine the data obtained in quiet geomagnetic conditions and during geomagnetic storms. Since during geomagnetic disturbances the ion fluxes may be changed by 1-2 orders of magnitude (for example, see [17,18,21]) such a method of data averaging leads to a spreading of the model parameters (especially at large L ).…”

Section: Description Of the Modelmentioning

confidence: 99%

“…4 that our model needs further improvement, especially at L > 4.5. One should bear in mind that the α -particle fluxes may strongly vary at an increase of geomagnetic activity (for example, see [17,18,21]). …”

Section: Description Of the Modelmentioning

confidence: 99%

“…The modeling was performed on the basis of the experimental results presented in [4,[7][8][9][10][12][13][14][15][16][17][18][19][20], and also using the data of the Kosmos series satellites (due to some reasons these data have never been published). In the same way as it has been done for the empirical model of proton fluxes [1], Table 1.…”

Section: Description Of the Modelmentioning

confidence: 99%

“…The fluxes of α -particles with E > 1 MeV in ERB considered in this paper have been detected in experiments onboard the satellites Injun -4 [7 -8], 1966-70 A and 1968-26 B [9], OGO -4 [10], Injun -5 [8,11], OV 1-19 [12], 1972-076 B [13], Molniya-2 [14], Prognoz-5 [15], Explorer-45 [4,[16][17][18], ATS-6 [19], ISEE-1 [20], CRRES [21], OHZORA (ETS VI) and † Deceased.…”

Section: Introductionmentioning

confidence: 99%

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An Empirical Model of the Radiation Belt of Helium Nuclei

et al. 2005

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Based on satellite data, we present the results of modeling the spatial and energy distributions of integral fluxes of He nuclei ( α particles) with E > 1, 2, 4, and 7 MeV at L = 1.1-6.6 in a broad range of B / B 0 ( E is the kinetic energy of particles, L is the drift shell parameter, and Ç / B 0 is the magnetic field ratio). Some ways of practically applying the model are considered. The results of calculation of α -particle fluxes for a circular orbit with a height of 300 km and an inclination of 50° are presented.

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Section: Description Of the Modelmentioning

confidence: 99%

Section: Description Of the Modelmentioning

confidence: 99%

Section: Description Of the Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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An Empirical Model of the Radiation Belt of Helium Nuclei

et al. 2005

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“…The observed C/O ratio of ,...., 0.0004 is much less than that of solar energetic particles or the solar wind (where C/O ,...., 0.5), the Ne/O ratio of,...., 0.04 is much greater than that in the ionosphere (where Ne/O ,...., 5 x 10-4 ). These and other sources may also contribute to the population of trapped heavy ions, especially at lower energies, where there have been a number of earlier observations of nuclei with Z > 2 (see e.g., the review by Spjeldvik and Fritz [1983]). It is clear, however, that trapped ACRs have been the dominant source of high energy(> 10 MeV /nuc) heavy ions with Z > 2 observed in the radiation belts over the past decade.…”

Section: ) Qsmentioning

confidence: 99%

Anomalous Cosmic Rays: The Principal Source of High Energy Heavy Ions in the Radiation Belts

Mewaldt

Selesnick

Cummings

2013

Radiation Belts: Models and Standards

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Recent observations from SAMPEX have shown that "anomalous cosmic rays" are the principal source of high energy(> lOMeV /nuc) heavy ions trapped in the radiation belts. This component of interplanetary particles is known to originate from interstellar atoms that has been accelerated to high energies in the outer heliosphere. The mechanism by which anomalous cosmic rays with ,...., 1 to ,...., 50 Me V / nuc are trapped in a radiation belt at L ~ 2 has now been verified. We discuss models for accelerating and trapping anomalous cosmic rays and review observations of their composition, energy spectra, pitch angle distribution, and time variations. Extrapolation of the fluxes observed at ,...., 600 km to higher altitude and other time periods is also discussed.

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POLAR spacecraft observations of helium ion angular anisotropy in the Earth's radiation belts

et al. 1999

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Abstract. New observations of energetic helium ion fluxes in the Earth's radiation belts have been obtained with the CAMMICE/HIT instrument on the ISTP/GGS POLAR spacecraft during the extended geomagnetically low activity period April through October 1996. POLAR executes a high inclination trajectory that crosses over both polar cap regions and passes over the geomagnetic equator in the heart of the radiation belts. The latter attribute makes possible direct observations of nearly the full equatorial helium ion pitch angle distributions in the heart of the Earth's radiation belt region. Additionally, the spacecraft often re-encounters the same geomagnetic flux tube at a substantially off-equatorial location within a few tens of minutes prior to or after the equatorial crossing. This makes both the equatorial pitch angle distribution and an expanded view of the local off-equatorial pitch angle distribution observable. The orbit of POLAR also permitted observations to be made in conjugate magnetic local time sectors over the course of the same day, and this afforded direct comparison of observations on diametrically opposite locations in the Earth's radiation belt region at closely spaced times. Results from four helium ion data channels covering ion kinetic energies from 520 to 8200 KeV show that the distributions display trapped particle characteristics with angular flux peaks for equatorially mirroring particles as one might reasonably expect. However, the helium ion pitch angle distributions generally flattened out for equatorial pitch angles below about 45°. Significant and systematic helium ion anisotropy difference at conjugate magnetic local time were also observed, and we report quiet time azimuthal variations of the anisotropy index.Key words. Magnetospheric physics (energetic particles · trapped; magnetospheric configuration and dynamics; plasmasphere)

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Experimental Determination of Geomagnetically Trapped Energetic Heavy Ion Fluxes

Cited by 13 publications

References 76 publications

An Empirical Model of the Radiation Belt of Helium Nuclei

An Empirical Model of the Radiation Belt of Helium Nuclei

Anomalous Cosmic Rays: The Principal Source of High Energy Heavy Ions in the Radiation Belts

POLAR spacecraft observations of helium ion angular anisotropy in the Earth's radiation belts

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