Time and altitude dependence of 55-Mev trapped protons, August 1961 to June 1964

Filz, R. C.; Holeman, E.

doi:10.1029/jz070i023p05807

Cited by 45 publications

(16 citation statements)

References 24 publications

(9 reference statements)

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“…The east-west asyminetry in the directional flux of energetic trapped protons [Lenchek and Singer, 1962] is clearly observed at low satellite altitudes in the South Atlantic anomaly [Heckman and Nakano, 1963;Galperin and Temny, 1965;and Filz and Holeman, 1965]. That an east-west flux asymmetry is a general feature of inner belt protons is supported by the ExplorerH satellite observations by Garmire [1963].…”

Section: Verification Of Orientationmentioning

confidence: 86%

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Low-altitude trapped protons during Solar Minimum Period, 1962-1966

Heckman¹,

Nakano²

1969

J. Geophys. Res.

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Section: Verification Of Orientationmentioning

confidence: 86%

“…The minimum thickness of 2.48 g/cm 2 is in the direction normal to the detector surfaces. The minimum detect- [Heckman and Nakano, 1963;Filz and Holeman, 1965].…”

Section: Orientation Of Emulsionmentioning

confidence: 99%

Low-altitude trapped protons during Solar Minimum Period, 1962-1966

Heckman¹,

Nakano²

1969

J. Geophys. Res.

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“…3). This altitudinal dependence in the bottom part of the IRB is a well-known phenomenon which has been competently described elsewhere (Filz & Holeman 1965;Gusev et al 2003;Dachev 2013b). It is remarkable that during the EXPOSE-R mission the values of the hourly and daily average dose rates were much higher than those of the EXPOSE-E mission.…”

Section: Irb Dose Rates and Proton Energiesmentioning

confidence: 61%

EXPOSE-R cosmic radiation time profile

Dachev

Horneck²,

Häder

et al. 2014

International Journal of Astrobiology

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The aim of the paper is to present the time profile of cosmic radiation exposure obtained by the radiation risks radiometer-dosimeter (R3DR) during the ESA exposition facility for EXPOSE-R mission (EXPOSE-R) in the EXPOSE-R facility outside the Russian Zvezda module of the International Space Station (ISS). Another aim is to make the obtained results available to other EXPOSE-R teams for use in their data analysis. R3DR is a low mass and small dimensions automated device, which measures solar radiation in four channels and in addition cosmic ionizing radiation. The main results of cosmic ionizing radiation measurements are: three different radiation sources were detected and quantified: galactic cosmic rays (GCR), energetic protons from the inner radiation belt (IRB) in the region of the South Atlantic anomaly and energetic electrons from the outer radiation belt (ORB). The highest daily averaged absorbed dose rate of 506 μGy day − 1 came from IRB protons; GCR delivered much smaller daily absorbed dose rates of 81.4 μGy day − 1 on average, and ORB source delivered on average a dose rate of 89 μGy day − 1 . The IRB and ORB daily averaged absorbed dose rates were higher than those observed during the ESA exposition facility for EXPOSE-E mission (EXPOSE-E), whereas the GCR rate was smaller than that measured during the EXPOSE-E mission. The reason for this difference is much less surrounding constructions shielding of the R3DR instrument in comparison with the R3DE instrument.

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“…For LEO, 30 MeV protons have lifetimes of >20 years, according to studies based on drift shell tracing [ Pu et al , 2005]. On the other hand, at LEO orbits below 500 km, lifetime are less than a few years [ Filz and Holeman , 1965]. Theoretical work by Farley and Walt [1971] and Selesnick et al [2007] suggested that the Cosmic Ray Albedo Neutron Decay (CRAND) is the dominant source of protons with energy >100 MeV or L < 1.3, and solar energetic protons (SEP) are dominated source for energies <100 MeV and for L > 1.3.…”

Section: Lifetime Of Energetic Protons In the Radiation Belts–physicsmentioning

confidence: 99%

“…Morphologically we can distinguish two regions, the inner RB for L shells lower than two and the outer RB for L shells higher than two. The inner RB is dominated by protons with energy in excess of 10 MeV and lifetimes from a few years at low altitudes of 400–500 km [ Filz and Holeman , 1965] to many tens of years at higher altitudes [ Selesnick et al , 2007]. Overall the inner belt energetic protons are relatively stable with a typical lifetime of ∼10 years.…”

Section: Introductionmentioning

confidence: 99%

Control of the energetic proton flux in the inner radiation belt by artificial means

2009

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[1] Earth's inner radiation belt located inside L = 2 is dominated by a relatively stable flux of trapped protons with energy from a few to over 100 MeV. Radiation effects in spacecraft electronics caused by the inner radiation belt protons are the major cause of performance anomalies and lifetime of Low Earth Orbit satellites. For electronic components with large feature size, of the order of a micron, anomalies occur mainly when crossing the South Atlantic Anomaly. However, current and future commercial electronic systems are incorporating components with submicron size features. Such systems cannot function in the presence of the trapped 30-100 MeV protons, as hardening against such high-energy protons is essentially impractical. The paper discusses the basic physics of the interaction of high-energy protons with low-frequency Shear Alfven Wave (SAW) under conditions prevailing in the radiation belts. Such waves are observed mainly in the outer belt, and it is believed that they are excited by an Alfven Ion Cyclotron instability driven by anisotropic equatorially trapped energetic protons. The paper derives the bounce and drift-averaged diffusion coefficients and uses them to determine the proton lifetime as a function of the spectrum and amplitude of the volume-averaged SAW resonant with the trapped energetic protons. The theory is applied to the outer and inner radiation belts. It is found that the resonant interaction of observed SAW with nT amplitude in the outer belt results in low flux of trapped protons by restricting their lifetime to periods shorter than days. A similar analysis for the inner radiation belt indicates that broadband SAW in the 1-10 Hz frequency range and average amplitude of 25 pT would reduce the trapped energetic proton flux by more than an order of magnitude within 2 to 3 years. In the absence of naturally occurring SAW waves, such reduction can be achieved by injecting such waves from ground-based transmitters. The analysis indicates that such reduction requires injection of less than 10 kW of SAW power. Increasing the power will result in the further decrease of the trapped flux. The paper concludes with a brief discussion of techniques that can inject such waves using ground-based transmitters.Citation: Shao, X., K. Papadopoulos, and A. S. Sharma (2009), Control of the energetic proton flux in the inner radiation belt by artificial means,

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Time and altitude dependence of 55-Mev trapped protons, August 1961 to June 1964

Cited by 45 publications

References 24 publications

Low-altitude trapped protons during Solar Minimum Period, 1962-1966

Low-altitude trapped protons during Solar Minimum Period, 1962-1966

EXPOSE-R cosmic radiation time profile

Control of the energetic proton flux in the inner radiation belt by artificial means

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