Upper cutoff of high energy solar protons

Heristchi, D.; Trottet, G.; Pérez‐Peraza, J.

doi:10.1007/bf00221491

Cited by 18 publications

(15 citation statements)

References 20 publications

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“…Standard observations by the surface detectors allowed to estimate, for example, the magnitude of R m ¼ 20 (+10, À4) GV (Heristchi et al 1976) by the data on the February 23, 1956 GLE -a largest one since 1942 (historical beginning of regular SCR observations). Meanwhile, by the data of non-standard surface muon telescopes (Sarabhai et al 1956), solar protons have been recorded in the range of 35-67.5 GeV during initial stage of the same event.…”

Section: Search For Extremely High-energy Particlesmentioning

confidence: 99%

“…Up to 1990 it has been possible to determine the quantity E m (R m ) for 18 events only (Heristchi et al 1976;Bazilevskaya and Makhmutov 1988;Kocharov 1983;Zusmanovich and Shvartsman 1989). It is still under discussion several estimates of E m for the event of September 29, 1989 .…”

Section: Determination Of R M From Observational Datamentioning

confidence: 99%

“…In order to verify a possible relation between R m and the number of accelerated protons, N a , we have compiled the Table 4.3 which includes the values of R m , N a (>0.24 GV) and Miroshnichenko et al 2000, Miroshnichenko and. The corresponding references are: HTP-1976 (Heristchi et al 1976), BM-1988 (Bazilevskaya andMakhmutov 1988), K-1983K- (Kocharov 1983, and ZS-1989 (Zusmanovich and Shvartsman 1989) N a (>1.0 GV) (E p >30 and >433 MeV, respectively) for all 19 proton events. The estimates of N a have been obtained by involving the data on source spectra of solar cosmic rays of 1949.…”

Section: Determination Of R M From Observational Datamentioning

confidence: 99%

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Solar Cosmic Rays

Miroshnichenko

2015

Astrophysics and Space Science Library

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Section: Search For Extremely High-energy Particlesmentioning

confidence: 99%

Section: Determination Of R M From Observational Datamentioning

confidence: 99%

Section: Determination Of R M From Observational Datamentioning

confidence: 99%

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Solar Cosmic Rays

Miroshnichenko

2015

Astrophysics and Space Science Library

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“…We present approximate analytical solutions valid through the entire energy range, including the transrelativistic range, for both the time-dependent and the stationary solutions. (2) With the derived energy spectra we determine how much information is lost by neglecting the dispersive rate in equation (1), as is some times done in the literature (e.g., Ginzburg & Syrovatskii 1964;Cheng 1972;Heristchi et al 1976;Pikel'ner & Livishts 1977;Eichler 1979;Vilmer et al 1982Vilmer et al , 1986MacKinnon et al 1983). (3) We attempt to establish the range of acceleration parameters in solar source conditions under which the neglect of the dispersive term does not introduce an important deviation from the actual particle energy spectrum; that is, whether the diffusive fundamental essence of a stochastic process may be substituted by the secular behavior of an average systematic acceleration rate.…”

Section: Introductionmentioning

confidence: 99%

Weightiness of the Dispersive Rate in Stochastic Acceleration Processes

Pérez‐Peraza¹,

Gallegos-Cruz²

1994

International Astronomical Union Colloquium

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We present analytical solutions to the transport equation of the accelerated particles that are valid over the entire energy range (nonrelativistic, transrelativistic, and ultrarelativistic) for the time-dependent and equilibrium cases. On the basis of these overall spectra, we have studied the relative importance of the term of average (systematic) energy increase and the term of diffusion (spread) in energy that define the evolution of accelerated particles within the frame of a simplified diffusion-convection transport equation, when the particle distribution function N(E, t) is assumed to be independent of spatial pitch-angle diffusion (isotropic). Since in some astrophysical works, only the term of average energy increase in the simplified transport equation in energy space is considered to be leading directly to a power-law-type spectrum, we have established the conditions under which such an approximation may be justified. The analysis is illustrated for acceleration by two different kinds of turbulence: MHD and Langmuir waves. The omission of the term of energy spread leads, in general, to an important depletion or overproduction of the accelerated particle flux that must be seriously considered in any calculation of the flux of secondary radiation produced by the accelerated particles. The presented analytical spectra may be of particular relevance to gamma-ray, neutron, and pion production in solar flares as well as in other astrophysical sites.

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“…This law holds up to a maximum energy E,, or a maximum rigidity R m beyond which the intensity drops to zero. Such a spectrum has been determined by Heristchi et al (1972) for the case of the 1-2 September 1971 proton event. The sea level counting rates of the worldwide network of neutron monitors were used and the mean values obtained for the different parameters are:…”

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confidence: 99%

Determination of the upper cutoff of the 1?2 September 1971 proton event from satellite measurements

Heristchi¹,

Trottet²

1975

Sol Phys

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The existence of an upper cutoff in the solar proton spectrum has been shown by Heristchi and Trottet (1971). In this work, the differential spectrum, against energy or rigidity, is represented by a power law, the exponent of which is y or #, respectively. This law holds up to a maximum energy E,, or a maximum rigidity R m beyond which the intensity drops to zero. Such a spectrum has been determined by Heristchi et al. (1972) for the case of the 1-2 September 1971 proton event. The sea level counting rates of the worldwide network of neutron monitors were used and the mean values obtained for the different parameters are:For the same event, Vernov et al. (1973) present direct measurements of the proton integral spectrum. These measurements were made from satellite, the high energy part of the spectrum being obtained by the latitude effect. These observations show that, between 30 MeV and 2 GeV, it is impossible to account for the spectrum by either a single power law or an exponential law. Applying to Vernov's data a differential spectrum represented by a power law with an upper cutoff, we obtain: E,,, = (1.8 + 0.5) GeV; R,, = (2.6 _ 0.6) GV; 7 = 2.0 + 0.3, /~ = 2.6 + 0.4.The experimental points and the integral spectra corresponding to the above values of the parameters are plotted on Figure 1. Examination of the figure shows that there is a good agreement between the experimental points and our spectrum, for energy as well as for rigidity. However, there is a difference between those values of the parameters derived from neutron monitor data and those from direct measurements (mainly for the values of 7 and #). We think that these differences are due to the lack of precision of the data but mainly in the method used by Vernov et al. to determine the energy of the particles, especially in the high energy range. Nevertheless, the observations of these authors, clearly exhibit the presence of an upper cutoff in the solar proton spectrum and confirm its existence. Solar Physics 41 (1975) 459-460. All Rights Reserved Copyright 9 1975 by D. Reidel Publishing Company, Dordrecht-Holland

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Upper cutoff of high energy solar protons

Cited by 18 publications

References 20 publications

Solar Cosmic Rays

Solar Cosmic Rays

Weightiness of the Dispersive Rate in Stochastic Acceleration Processes

Determination of the upper cutoff of the 1?2 September 1971 proton event from satellite measurements

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