Differential energy spectrum of geomagnetically trapped protons with the Esro 2 satellite

Valot, P.

doi:10.1029/ja077i013p02309

Cited by 14 publications

(7 citation statements)

References 22 publications

(8 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…MeV. This bend has also been found for higher L shells, 1.6 _< L _< 2.2 [Valor, 1972], where it is still more pronounced. This Fig.…”

Section: Show An Indication Of a Slight Bend For Proton Energies E• supporting

confidence: 63%

“…. A comparison of the 155-MeV data ofValor and Engelmann [1973] at L = 1.4, B/Bo = 1.54 and those ofValor [1972] at L = 1.4, B/Bo = 1.853 shows that an extrapolation of the straight line with n = 6 beyond B/Bo = 1.54 would lead to a value at B/Bo = 1.853 which is a factor of 2 higher than that actually observed. By first applying this factor to all energies and then extrapolating to the equator by using the exponents ofTable 2we have determined the equatorial fluxes, which are plotted as solid circles inFigure 9.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Angular distribution and energy spectra of protons of energy 5 ≤E≤ 50 MeV at the lower edge of the radiation belt in equatorial latitudes

Fischer¹,

Auschrat²,

Wibberenz³

1977

J. Geophys. Res.

View full text Add to dashboard Cite

The population of protons having energy 5 <_ E, <_ 50 MeV at the inner boundary of the radiation belt was investigated in near-equatorial latitudes by a particle telescope having large gathering power and, consequently, high statistical accuracy. The measurements were performed from March l0 until May 10, 1970, on board the second German research satellite Dial. A nearly complete coverage was obtained for the region 1.15 < L < 1.40 and I < B/Bo < 1.7. Particle fluxes are ordered as a function of B/Bo, L being fixed. For B/Bo values corresponding to mirror point heights above 300 -t-50 km the fluxes follow a (B/Bo) -n/2 law which can be converted to equatorial pitch angle distributions J• sin n 0 via Liouville's theorem. For 1.15 < L < 1.25 the exponent n increases steeply with decreasing L and the shape of the energy spectrum J• remains essenbally constant. At this lower edge of the radiation belt the proton population in the above energy range is determined from an equilibrium between the cosmic ray albedo neutron decay source and atmospheric loss processes. For larger L, radial diffusion sets in and leads to a distortion of the spectrum, with a shift of the intensity maximum toward lower energies with increasing L. The observed spectra are in satisfactory agreement with solutions of the transport equation (Claflin and White, 1974) based on one-and two-term diffusion coefficients.

show abstract

“…MeV. This bend has also been found for higher L shells, 1.6 _< L _< 2.2 [Valor, 1972], where it is still more pronounced. This Fig.…”

Section: Show An Indication Of a Slight Bend For Proton Energies E• supporting

confidence: 63%

mentioning

confidence: 99%

Angular distribution and energy spectra of protons of energy 5 ≤E≤ 50 MeV at the lower edge of the radiation belt in equatorial latitudes

Fischer¹,

Auschrat²,

Wibberenz³

1977

J. Geophys. Res.

View full text Add to dashboard Cite

show abstract

“…Figure 2 which is a continuous function consisting of four piecewiseexponential segments (k = 0, 1, 2, 3), were determined from the counting rates observed in the seven energy channels (see Table 1 We have compared the present deconvolution of J_•(E) with values obtained about 1 year earlier by Valot [1972], using an instrument with much better energy resolution than that of ours. Valot [1972] had adopted a piecewise-exponential representation of Jl(E) and had found two segments sufficient to fit the spectrum over the energy range E • 30-300 MeV at L $2 (one segment being sufficient for L • 2). His data contain only a hint of the spectral minimum that we discern at E • 20 MeV.…”

Section: Data Reductionmentioning

confidence: 99%

Radial diffusion of inner-zone protons: Observations and variational analysis

Croley¹,

Schulz²,

Blake³

1976

J. Geophys. Res.

View full text Add to dashboard Cite

Omnidirectional proton intensities (E ≈ 9‐310 MeV) have been measured in seven energy channels by means of instruments on board the satellite OV1‐19 (1969‐25C). Unidirectional spectra representative of the time interval March–November 1969 (a period near solar maximum) have been constructed from the data by standard methods. The results enable one to construct the distribution functionf(M, L) at vanishing second invariant J for 1.18 ≤ L ≤ 2. The profiles of f(M, L) thus obtained are manipulated by a new variational method to yield normalization parameters for the radial diffusion coefficients DLL(m) and DLL(e), caused, respectively, by magnetic and electrostatic impulses of magnetospheric extent. One typically obtains DLL ∼ [7 × 10−9 + 1 × 10−10 × (γM0/M)²]L10 day−1 as the best two‐parameter fit to DLL ≡ DLL(m) + DLL(e), where M0 ≡ 1 GeV/G and γ is the ratio of relativistic mass (m) to rest mass (m0).

show abstract

“…The horizontal axis represents the space proton energy, and the vertical axis represents the differential flux. The differential energy spectrum of high energy protons within the radiation belt is generally of the power exponent form, which approximates to a straight line in the logarithmic coordinates (Valot, 1972). It can be observed from Figure 6 that the space energy spectrum obtained from inversion of the geometrical factor G tr through numerical calculation appears obvious broken line structure, which is obviously different from the distribution rule of energy spectrum of space protons.…”

Section: Binmentioning

confidence: 93%

The geometric factor of high energy protons detector on FY-3 satellite

Zhang

Wang

et al. 2014

Sci. China Earth Sci.

View full text Add to dashboard Cite

Geometric factor is the key parameter for inversion of particle spectrum in space particle detection. Traditional geometric factor is obtained through the method of numerical calculation with the actual structure of the detector as the input condition. The degree of accuracy for data inversion is reduced since traditional geometric factor fails to take into account the physical process of interaction between the particle and substance as well as the influence of factors such as the particle interference between different energy channels on the measurement result. Here we propose an improved geometrical factor calculation method, the concept of which is to conduct actual structural modelling of the detector in the GEANT4 program, consider the process of interaction between the particle and substance, obtain the response function of the detector to particles of different energy channels through the method of Monte Carlo simulation, calculate the influence of contaminated particle on the geometrical factor, and finally get the geometrical factors for different energy channels of the detector. The imrpoved geometrical factor obtained through the method has carried out inversion for the data of high energy protons detector on China's FY-3 satellite, the energy spectrum after which is more in line with the power law distribution recognized by space physics. The comparison with the measured result of POES satellite indicates that the FY-3 satellite data are in good accordance with the satellite data, which shows the method may effectively improve the quality of data inversion. geometrical factor, response function, particle radiation, space detection, FY-3 Citation:The high energy protons detector (HPD) on FY-3 satellite (A/B) is developed by the Center for Space Science and Applied Research, Chinese Academy of Sciences. HPD is used to measure the energy spectrum of solar high energy protons during the high energy protons and solar burst within the radiation belt of the earth. The range of measurement is 3-300 MeV, which falls into six energy channels, and serves for space weather forecast and alarm of the National Weather Service (Huang et al., 2012).Important for the detector, the geometrical factor is the essential parameter for inversion of the direct measurement quantity of the detector to space physical quantity. The direct measurement quantity of HPD is the count N (s 1 ) of each energy channel recorded by the detector per unit time. The differential directional flux J (cm 2 sr 1 s 1 ) of space particle is required for more intuitive expression of the space environment in space physics. The conversion rela-

show abstract

Differential energy spectrum of geomagnetically trapped protons with the Esro 2 satellite

Cited by 14 publications

References 22 publications

Angular distribution and energy spectra of protons of energy 5 ≤E≤ 50 MeV at the lower edge of the radiation belt in equatorial latitudes

Angular distribution and energy spectra of protons of energy 5 ≤E≤ 50 MeV at the lower edge of the radiation belt in equatorial latitudes

Radial diffusion of inner-zone protons: Observations and variational analysis

The geometric factor of high energy protons detector on FY-3 satellite

Contact Info

Product

Resources

About