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Letteratura scientifica selezionata sul tema "Cosmic-ray transport"

Autore: Grafiati

Pubblicato: 14 marzo 2023

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Articoli di riviste sul tema "Cosmic-ray transport"

Schlickeiser, Reinhard. "Cosmic-ray transport and acceleration". Astrophysical Journal Supplement Series 90 (febbraio 1994): 929. http://dx.doi.org/10.1086/191927.

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Biermann, Peter L., Julia Becker Tjus, Eun-Suk Seo e Matthias Mandelartz. "COSMIC-RAY TRANSPORT AND ANISOTROPIES". Astrophysical Journal 768, n. 2 (22 aprile 2013): 124. http://dx.doi.org/10.1088/0004-637x/768/2/124.

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Duffy, Peter, e Katherine M. Blundell. "Cosmic ray transport and acceleration". Plasma Physics and Controlled Fusion 47, n. 12B (11 novembre 2005): B667—B678. http://dx.doi.org/10.1088/0741-3335/47/12b/s49.

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Schlickeiser, Reinhard. "Cosmic-Ray Transport and Acceleration". International Astronomical Union Colloquium 142 (1994): 926–36. http://dx.doi.org/10.1017/s0252921100078337.

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AbstractWe review the transport and acceleration of cosmic rays concentrating on the origin of galactic cosmic rays. Quasi-linear theory for the acceleration rates and propagation parameters of charged test particles combined with the plasma wave viewpoint of modeling weak cosmic electromagnetic turbulence provides a qualitatively and quantitatively correct description of key observations. Incorporating finite frequency effects, dispersion, and damping of the plasma waves are essential in overcoming classical discrepancies with observations as the Kfit - Kql discrepancy of solar particle events. We show that the diffusion-convection transport equation in its general form contains spatial convection and diffusion terms as well as momentum convection and diffusion terms. In particular, the latter momentum diffusion term plays a decisive role in the acceleration of cosmic rays at super-Alfvénic supernova shock fronts, and in the acceleration of ultra-high-energy cosmic rays by distributed acceleration in our own galaxy.Subject headings: acceleration of particles — convection — cosmic rays — diffusion — shock waves

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Maiti, Snehanshu, Kirit Makwana, Heshou Zhang e Huirong Yan. "Cosmic-ray Transport in Magnetohydrodynamic Turbulence". Astrophysical Journal 926, n. 1 (1 febbraio 2022): 94. http://dx.doi.org/10.3847/1538-4357/ac46c8.

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Abstract This paper studies cosmic-ray (CR) transport in magnetohydrodynamic (MHD) turbulence. CR transport is strongly dependent on the properties of the magnetic turbulence. We perform test particle simulations to study the interactions of CR with both total MHD turbulence and decomposed MHD modes. The spatial diffusion coefficients and the pitch angle scattering diffusion coefficients are calculated from the test particle trajectories in turbulence. Our results confirm that the fast modes dominate the CR propagation, whereas Alfvén and slow modes are much less efficient and have shown similar pitch-angle scattering rates. We investigate the cross field transport on large and small scales. On large/global scales, normal diffusion is observed and the diffusion coefficient is suppressed by M A ζ compared to the parallel diffusion coefficients, with ζ closer to 4 in Alfvén modes than that in total turbulence, as theoretically expected. For the CR transport on scales smaller than the turbulence injection scale, both the local and global magnetic reference frames are adopted. Superdiffusion is observed on such small scales in all the cases. Particularly, CR transport in Alfvén modes show clear Richardson diffusion in the local reference frame. The diffusion transitions smoothly from the Richardson’s one with index 1.5 to normal diffusion as the particle mean free path decreases from λ ∥ ≫ L to λ ∥ ≪ L, where L is the injection/coherence length of turbulence. Our results have broad applications to CRs in various astrophysical environments.

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Strauss, R. D., J. P. van den Berg e J. S. Rankin. "Cosmic-Ray Transport near the Sun". Astrophysical Journal 928, n. 1 (1 marzo 2022): 22. http://dx.doi.org/10.3847/1538-4357/ac582a.

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Abstract The strongly diverging magnetic field lines in the very inner heliosphere, through the associated magnetic focusing/mirroring forces, can, potentially, lead to highly anisotropic galactic cosmic-ray distributions close to the Sun. Using a simplified analytical approach, validated by numerical simulations, we study the behavior of the galactic cosmic-ray distribution in this newly explored region of the heliosphere and find that significant anisotropies can be expected inside 0.2 au.

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Strauss, R. D., H. Fichtner, M. S. Potgieter, J. A. le Roux e X. Luo. "Cosmic ray transport near the heliopause". Journal of Physics: Conference Series 642 (settembre 2015): 012026. http://dx.doi.org/10.1088/1742-6596/642/1/012026.

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Krumholz, Mark R., Roland M. Crocker, Siyao Xu, A. Lazarian, M. T. Rosevear e Jasper Bedwell-Wilson. "Cosmic ray transport in starburst galaxies". Monthly Notices of the Royal Astronomical Society 493, n. 2 (18 febbraio 2020): 2817–33. http://dx.doi.org/10.1093/mnras/staa493.

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ABSTRACT Starburst galaxies are efficient γ-ray producers, because their high supernova rates generate copious cosmic ray (CR) protons, and their high gas densities act as thick targets off which these protons can produce neutral pions and thence γ-rays. In this paper, we present a first-principles calculation of the mechanisms by which CRs propagate through such environments, combining astrochemical models with analysis of turbulence in weakly ionized plasma. We show that CRs cannot scatter off the strong large-scale turbulence found in starbursts, because efficient ion-neutral damping prevents such turbulence from cascading down to the scales of CR gyroradii. Instead, CRs stream along field lines at a rate determined by the competition between streaming instability and ion-neutral damping, leading to transport via a process of field line random walk. This results in an effective diffusion coefficient that is nearly energy independent up to CR energies of ∼1 TeV. We apply our computed diffusion coefficient to a simple model of CR escape and loss, and show that the resulting γ-ray spectra are in good agreement with the observed spectra of the starbursts NGC 253, M82, and Arp 220. In particular, our model reproduces these galaxies’ relatively hard GeV γ-ray spectra and softer TeV spectra without the need for any fine-tuning of advective escape times or the shape of the CR injection spectrum.

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Ptuskin, Vladimir. "Cosmic ray transport in the Galaxy". Journal of Physics: Conference Series 47 (1 ottobre 2006): 113–19. http://dx.doi.org/10.1088/1742-6596/47/1/014.

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Schlickeiser, R. "Cosmic ray transport in astrophysical plasmas". Physics of Plasmas 22, n. 9 (settembre 2015): 091502. http://dx.doi.org/10.1063/1.4928940.

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Tesi sul tema "Cosmic-ray transport"

RECCHIA, SARAH. "Non linear cosmic ray transport and cosmic ray driven galactic winds". Doctoral thesis, Gran Sasso Science Institute, 2016. http://hdl.handle.net/20.500.12571/13501.

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The bulk of Cosmic Rays (CRs) reaching our planet is likely of Galactic origin and is thought to be accelerated in sources located in the Galactic disk (mainly Supernova remnants (SNRs)). The energy density of Galactic CRs, ∼ 1 eV/cm3, can be accounted for if one assumes that 3-10% of the mechanical energy injected by SNe in the Galaxy is channeled into accelerated particles. The observed large residence time of CRs in the Galaxy (compared to the time required for ballistic propagation of relativistic particles on Galactic distances) suggests that Galactic CRs are well coupled to the interstellar medium (ISM) and are likely to undergo diffusive motion, due to scattering off magnetic turbulence in the ISM. Most of current models of CR propagation treat the CR transport properties (such as the diffusion coefficient and the size of the propagation region) as fitting parameters and do not take into account the possible active role of CRs in determining them. In fact, the escape of CRs from the Galaxy leads to a gradient in the CR distribution function which can cause the excitation of Alfvén waves, due to CR streaming instability, that in turn determine the scattering properties of CRs, namely their diffusive transport. In addition, the CR pressure gradient can act as a force on the background plasma, directed away from the Galactic disk. If this force is large enough to win against gravity (due to Dark Matter, gas and stars), a wind can be launched, which affects the CR convective transport. The dynamics of CR-driven winds in the presence of self-generated turbulence is intrinsically non-linear. In fact, the CR density gradient determines the wind properties (velocity, pressure, magnetic field) and the excitation of the plasma waves which cause CR diffusion. On the other hand, Galactic winds could have a sizable effect on the CR distribution function, by advecting CRs out of the Galaxy, by influencing their spectral features, by affecting their radial distribution in the Galactic disk but also, possibly, by reaccelerating them at the wind termination shock (see Zirakashvili & Voelk (2006)). In addition, in such a scenario the CR diffusion coefficient, convection velocity and the size of the propagation region are not pre assigned, but rather they are derived self-consistently with the CR distribution function. The importance of Galactic winds is not only restricted to CR physics. In fact, galactic outflows have been observed in many galaxies and constitute an important ingredient in the galactic evolution. For instance, galactic winds affect the amount of gas available and pollute the galactic halos with hot plasma and metals, thus influencing the properties of the ISM and the star formation rate. As for the Milky Way, observations have not yet provided a clear answer as to the existence of such outflows, although the detection of absorption lines in the X-ray band (Oxygen OV II and OV III lines) show the presence of a hot dilute gas in the Galactic halo and the recent observation of the so called Fermi Bubbles in the Galactic Center region are likely to be connected with Galactic winds. Galactic winds may be powered by several mechanisms, for instance by thermal and radiation pressure gradients. However those mechanisms are unlikely to occur in the Milky Way, with the only possible exception of the Galactic Center region, since thermal and radiation pressure gradients are expected to be too small. Nevertheless, the CR pressure gradient may provide the force necessary to launch winds, making CR-driving an appealing mechanism for wind formation in our Galaxy. In this thesis we solve the coupled system of the hydrodynamic equations for CR-driven winds and for the CR transport in such winds. In our approach the CR transport is due to diffusion on self-generated Alfvén waves and to advection with these waves and with the wind. We then apply our solution method to the Milky Way and we investigate: 1) how the wind launching depends on the properties of the ISM (gas density and temperature, Galactic magnetic field), on the CR pressure and on the Galactic gravitational potential (including the Dark Matter halo); 2) the implications of CR-driven winds on the observed CR proton spectrum; 3) the effect of non-linear CR propagation in the presence of self-generated diffusion, both with and without CR-driven winds, on the CR distribution function in the Galaxy as a function of the Galactocentric distance, and we compare our predictions with the observed radial CR density and spectral slope, as inferred from observations of γ-rays.

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Fornieri, Ottavio. "Cosmic-ray transport in the Milky Way and related phenomenology". Doctoral thesis, Università di Siena, 2021. http://hdl.handle.net/11365/1143115.

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In this thesis, we aim at studying some of the open questions regarding the origin of the "Cosmic Rays" (CRs), as well as their transport properties. The exceptional quality of the experimentally measured cosmic-ray observables, especially at the recently-achieved energies in the range ~O(100 GeV - 1 TeV), started to question the standard picture, based on a "Supernova Remnant"-(SNR)-only origin of the CRs and a diffusive propagation inspired by the "Quasi-Linear Theory" (QLT) of pitch-angle interaction against alfvénic turbulence. First, we reproduce the most relevant cosmic-ray observables to tune the propagation setup, numerically solving the transport equation with the DRAGON code. On top of this, to account for the rising of the e^+ above ~10 GeV, we fit a primary population of positrons originating in Pulsar Wind Nebulae, in a model-independent setup that considers the uncertainties in the pulsar injections mechanism. Since the all-lepton spectrum is still not reproduced above ~50 GeV --- and in particular the ~TeV break --- we consider the contribution from a nearby source of e^-, and conclude that an old t_{age} ~ 10^5 yr SNR, located between ~600 pc and ~1 kpc, is probably missing from the Catalogues. Within the hypothesis of such old remnant in its radiative phase contributing to the e^+ + e^-, we search for its signature in the proton flux as well. To do this, we consider a phenomenological propagation setup that reproduces the hadronic spectral hardening at ~200 GeV as a diffusive feature D(E) ~ E^delta(E), and adopt it consistently for the large-scale background and for the nearby source. Within this framework, we account for the all-lepton spectrum, the proton spectrum and the cosmic-ray dipole anisotropy with the same old (t_{age} = 2*10^5 yr), nearby (d = 300 pc) remnant. We highlight that the progressively hardening diffusion coefficient is a crucial ingredient, since, in a single-power-law diffusion scenario, the dipole anisotropy data would be overshot by, at least, one order of magnitude. Finally, we explore the phenomenological implications of a change of paradigm in the standard cosmic-ray diffusion --- based on wave-particle interaction with Alfvén fluctuations --- considering a non-linear extension of the QLT that enhances the efficiency of CR-scattering with the other "Magneto-Hydro-Dynamic" (MHD) modes. Indeed, assuming the anisotropy of the alfvénic cascade, its scattering rate at all energies below ~100 TeV is not able to confine charged cosmic rays, and the fast magnetosonic modes alone shape the diffusion coefficient that particles experience in the Galaxy. Within such picture, we implement the resulting D(E) in DRAGON2, where two independent zones differently affect the evolution of the MHD cascade: the Halo (L_{Halo} ~ 5-6 kpc) and the Warm Ionized Medium (L_{WIM} ~ 1 kpc). We find that, with a reasonable choice of selected quantities, representing the physics of the environments, we can reproduce the hadronic fluxes, as well as the boron-over-carbon ratio, from ~200 GeV above. We assign to the rising of the "streaming instabilities" the cosmic-ray transport below this energy.

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Singleterry, Robert Clay Jr. "Neutron transport associated with the galactic cosmic ray cascade". Diss., The University of Arizona, 1993. http://hdl.handle.net/10150/186421.

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Transport of low energy neutrons associated with the galactic cosmic ray cascade is analyzed in this dissertation. A benchmark quality analytical algorithm is demonstrated for use with B scRYNTRN, a computer program written by the High Energy Physics Division of N scASA Langley Research Center, which is used to design and analyze shielding against the radiation created by the cascade. B scRYNTRN uses numerical methods to solve the integral transport equations for baryons with the straight-ahead approximation, and numerical and empirical methods to generate the interaction probabilities. The straight-ahead approximation is adequate for charged particles, but not for neutrons. As N scASA Langley improves B scRYNTRN to include low energy neutrons, a benchmark quality solution is needed for comparison. The neutron transport algorithm demonstrated in this dissertation uses the closed-form Green's function solution to the galactic cosmic ray cascade transport equations to generate a source of neutrons. A basis function expansion for finite heterogeneous and semi-infinite homogeneous slabs with multiple energy groups and isotropic scattering is used to generate neutron fluxes resulting from the cascade. This method, called the F(N) method, is used to solve the neutral particle linear Boltzmann transport equation. As a demonstration of the algorithm coded in the programs M scGSLAB and M scGSEMI, neutron and ion fluxes are shown for a beam of fluorine ions at 1000 MeV per nucleon incident on semi-infinite and finite aluminum slabs. Also, to demonstrate that the shielding effectiveness against the radiation from the galactic cosmic ray cascade is not directly proportional to shield thickness, a graph of transmitted total neutron scalar flux versus slab thickness is shown. A simple model based on the nuclear liquid drop assumption is used to generate cross sections for the galactic cosmic ray cascade. The E scNDF/B V database is used to generate the total and scattering cross sections for neutrons in aluminum. As an external verification, the results from M scGSLAB and M scGSEMI were compared to A scNISN/P scC, a routinely used neutron transport code, showing excellent agreement. In an application to an aluminum shield, the F(N) method seems to generate reasonable results.

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Andreasen, Mie, Karsten H. Jensen, Marek Zreda, Darin Desilets, Heye Bogena e Majken C. Looms. "Modeling cosmic ray neutron field measurements". AMER GEOPHYSICAL UNION, 2016. http://hdl.handle.net/10150/621996.

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The cosmic ray neutron method was developed for intermediate-scale soil moisture detection, but may potentially be used for other hydrological applications. The neutron signal of different hydrogen pools is poorly understood and separating them is difficult based on neutron measurements alone. Including neutron transport modeling may accommodate this shortcoming. However, measured and modeled neutrons are not directly comparable. Neither the scale nor energy ranges are equivalent, and the exact neutron energy sensitivity of the detectors is unknown. Here a methodology to enable comparability of the measured and modeled neutrons is presented. The usual cosmic ray soil moisture detector measures moderated neutrons by means of a proportional counter surrounded by plastic, making it sensitive to epithermal neutrons. However, that configuration allows for some thermal neutrons to be measured. The thermal contribution can be removed by surrounding the plastic with a layer of cadmium, which absorbs neutrons with energies below 0.5 eV. Likewise, cadmium shielding of a bare detector allows for estimating the epithermal contribution. First, the cadmium difference method is used to determine the fraction of thermal and epithermal neutrons measured by the bare and plastic-shielded detectors, respectively. The cadmium difference method results in linear correction models for measurements by the two detectors, and has the greatest impact on the neutron intensity measured by the moderated detector at the ground surface. Next, conversion factors are obtained relating measured and modeled neutron intensities. Finally, the methodology is tested by modeling the neutron profiles at an agricultural field site and satisfactory agreement to measurements is found.

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Snyman, Jasper Lodewyk. "Modelling of the heliosphere and cosmic ray transport / Jasper L. Snyman". Thesis, North-West University, 2007. http://hdl.handle.net/10394/1814.

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Nkosi, Godfrey Sibusiso. "A study of cosmic ray anisotropies in the heliosphere / Godfrey Sibusiso Nkosi". Thesis, North-West University, 2006. http://hdl.handle.net/10394/1627.

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Nndanganeni, Rendani Rejoyce. "Modelling of galactic cosmic ray electrons in the heliosphere / Nndanganeni, R.R". Thesis, North-West University, 2012. http://hdl.handle.net/10394/7034.

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The Voyager 1 spacecraft is now about 25 AU beyond the heliospheric termination shock and soon it should encounter the outer boundary of the heliosphere, the heliopause. This is set to be at 120 AU in the modulation model used for this study. This implies that Voyager 1, and soon afterwards also Voyager 2, should be able to measure the heliopause spectrum, to be interpreted as the lowest possible local interstellar spectrum, for low energy galactic electrons (1 MeV to 120 MeV). This could give an answer to a long outstanding question about the spectral shape (energy dependence) of the galactic electron spectrum at these low energies. These in situ electron observations from Voyager 1, until the year 2010 when it was already beyond 112 AU, are used for a comparative study with a comprehensive three dimensional numerical model for the solar modulation of galactic electrons from the inner to the outer heliosphere. A locally developed steady state modulation model which numerically solves the relevant heliospheric transport equation is used to compute and study modulated electron spectra from Earth up to the heliopause. The issue of the spectral shape of the local interstellar spectrum at these low energies is specifically addressed, taking into account modulation in the inner heliosheath, up to the heliopause, including the effects of the transition of the solar wind speed from supersonic to subsonic in the heliosheath. Modulated electron spectra from the inner to the outer heliosphere are computed, together with radial and latitudinal profiles, focusing on 12 MeV electrons. This is compared to Voyager 1 observations for the energy range 6–14 MeV. A heliopause electron spectrum is computed and presented as a new plausible local interstellar spectrum from 30 GeV down to 10 MeV. The comparisons between model predictions and observations from Voyager 1 and at Earth (e.g. from the PAMELA mission and from balloon flights) and in the inner heliosphere (e.g. from the Ulysses mission) are made. This enables one to make conclusions about diffusion theory applicable to electrons in the heliosphere, in particular the rigidity dependence of diffusion perpendicular and parallel to the local background solar magnetic field. A general result is that the rigidity dependence of both parallel and perpendicular diffusion coefficients needs to be constant below P < 0.4 GV and only be allowed to increase above this rigidity to assure compatibility between the modeling and observations at Earth and especially in the outer heliosphere. A modification in the radial dependence of the diffusion coefficients in the inner heliosheath is required to compute realistic modulation in this region. With this study, estimates of the intensity of low energy galactic electrons at Earth can be made. A new local interstellar spectrum is computed for these low energies to improve understanding of the modulation galactic electrons as compared to previous results described in the literature.
Thesis (M.Sc. (Physics))--North-West University, Potchefstroom Campus, 2012.

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Tolksdorf, Tobias René [Verfasser], Reinhard [Gutachter] Schlickeiser e Horst [Gutachter] Fichtner. "Cosmic ray transport in superbubbles / Tobias René Tolksdorf ; Gutachter: Reinhard Schlickeiser, Horst Fichtner ; Fakultät für Physik und Astronomie". Bochum : Ruhr-Universität Bochum, 2021. http://d-nb.info/1226429041/34.

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Ngobeni, Mabedle Donald. "Aspects of the modulation of cosmic rays in the outer heliosphere / by Mabedle Donald Ngobeni". Thesis, North-West University, 2006. http://hdl.handle.net/10394/97.

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A time-dependent two-dimensional (2D) modulation model including drifts, the solar wind tennination shock (TS) with diffusive shock acceleration and a heliosheath based on the Parker (1965) transport equation is used to study the modulation of galactic cosmic rays (GCRs) and the anomalous component of cosmic rays (ACRs) in the heliosphere. In particular, the latitude dependence of the TS compression ratio and injection efficiency of the ACRs (source strength) based on the hydrodynamic modeling results of Scherer et al. (2006) is used for the first time in a modulation model. The subsequent effects on differential intensities for both GCRs and ACRs are illustrated, comparing them to the values without a latitude dependence for these parameters. It is found that the latitude dependence of these parameters is important and that it enables an improved description of the modulation of ACRs beyond the TS. With this modeling approach (without fitting observations) to the latitude dependence of the two parameters, it is possible to obtain a TS spectrum for ACRs at a polar angle of B = 55" that qualitatively approximates the main features of the Voyager 1 observations. This positive result has to be investigated further. Additionally, it is shown that the enhancement of the cosmic ray intensity just below the cut-off energy found for the ACR at the TS in an A < 0 magnetic polarity cycle in the equatorial plane with the latitude independent scenario, disappears in this region when the latitude dependence of the compression ratio and injection efficiency is assumed. Subsequent effects of these scenarios are illustrated on the global anisotropy vector of both GCRs and ACRs as the main theme of this work. For this purpose the radial and latitudinal gradients for GCRs and ACRs were accurately computed. The radial and latitudinal anisotropy components were then computed as a function of energy, radial distance and polar angle. It is also the first time that the anisotropy vector is comprehensively calculated in such a global approach to cosmic ray modeling in the heliosphere, in particular for ACRs. It is shown that the anisotropy vector inside (up-stream) and outside (down-stream) the TS behaves in a complicated way, so care must be taken in interpreting it. It is found that the latitude dependence of the two mentioned parameters can alter the direction (sign) of the anisotropy vector. Its behaviour beyond the TS is markedly different from inside the TS, mainly because of the slower solar wind velocity, with less dependence on the magnetic polarity cycles.
Thesis (M.Sc. (Physics))--North-West University, Potchefstroom Campus, 2007.

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Cohet, Romain. "Transport des rayons cosmiques en turbulence magnétohydrodynamique". Thesis, Montpellier, 2015. http://www.theses.fr/2015MONTS051/document.

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Dans cette thèse, nous étudions les propriétés du transport de particules chargées de haute énergie dans des champs électromagnétiques turbulents.Ces champs ont été générés en utilisant le code magnétohydrodynamique (MHD) RAMSES, résolvant les équations de la MHD idéales compressibles. Nous avons développé un module pour générer la turbulence MHD, en utilisant une technique de forçage à grande échelle. Les propriétés des équations de la MHD font cascader l'énergie des grandes échelles vers les petites, développant un spectre en énergie suivant une loi de puissance, appelée zone inertielle. Nous avons développé un module permettant de calculer les trajectoires de particule chargée une fois le spectre turbulent établi. En injectant les particules à une énergie telle que l'inverse du rayon de Larmor des particules corresponde à un mode du spectre de Fourier dans la zone inertielle, nous avons cherché à mettre en évidence un effet systématique lié à la loi de puissance du spectre. Cette méthode a montré que le libre parcours moyen est indépendant de l'énergie des particules jusqu'à des valeurs de rayon de Larmor proches de l'échelle de cohérence de la turbulence. La dépendance du libre parcours moyen avec le nombre de Mach alfvénique des simulations MHD a également produit une loi de puissance.Nous avons également développé une technique pour mesurer l'effet de l'anisotropie de la turbulence MHD sur les propriétés du transport des rayons cosmiques, au travers le calcul de champs magnétiques locaux. Cette étude nous a montré un effet sur coefficient de diffusion angulaire, accréditant l'hypothèse que les particules sont plus sensible aux variations de petites échelles
In this thesis, we study the transport properties of high energy charged particles in turbulent electromagnetic fields.These fields were generated by using the magnetohydrodynamic (MHD) code RAMSES, which solve the compressible ideal MHD equations. We have developed a module for generating the MHD turbulence, by using a large scale forcing technique. The MHD equations induce a cascading of the energy from large scales to small ones, developing an energy spectrum which follows a power law, called the inertial range.We have developed a module for computing the charged particle trajectories once the turbulent spectrum is established. By injecting the particles to energy such as the inverse of the particle Larmor radius corresponds to a mode in the inertial range of the Fourier spectrum, we have highlighted systematic effects related to the power law spectrum. This method showed that the mean free path is independent of the particules energy until the Larmor radius takes values close to the turbulence coherence scale. The dependence of the mean free path with the alfvénic Mach number produced a power law.We have also developed a technique to measure the anisotropy effect of the MHD turbulence in the cosmic rays transport properties through the calculation of local magnetic fields. This study has shown an effect on the pitch angle scattering coefficient, which confirmed the assumption that the particles are more sensitive to changes in small scales fluctuations

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Più fonti

Libri sul tema "Cosmic-ray transport"

S, Potgieter M., COSPAR Scientific Assembly e COSPAR Scientific Commission D, a cura di. Heliospheric cosmic ray transport, modulation and turbulence. Kidlington, Oxford: Published for the Committee on Space Research [by] Elsevier, 2005.

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W, Townsend Lawrence, e Langley Research Center, a cura di. A benchmark for galactic cosmic ray transport codes. Hampton, Va: Langley Research Center, 1987.

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United States. National Aeronautics and Space Administration. Scientific and Technical Information Program., a cura di. Calculations of cosmic-ray helium transport in shielding materials. [Washington, DC]: National Aeronautics and Space Administration, Office of Management, Scientific and Technical Information Program, 1993.

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Cucinotta, Francis A. Calculations of cosmic-ray helium transport in shielding materials. Hampton, Va: Langley Research Center, 1993.

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1940-, Wilson John W., e United States. National Aeronautics and Space Administration. Scientific and Technical Information Program., a cura di. An efficient HZETRN: (a galactic cosmic ray transport code). [Washington, DC]: National Aeronautics and Space Administration, Office of Management, Scientific and Technical Information Program, 1992.

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United States. National Aeronautics and Space Administration., a cura di. Time dependent simulation of cosmic-ray shocks including Alfvén transport. [Washington, DC: National Aeronautics and Space Administration, 1993.

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Shinn, Judy L. Fully energy-dependent HZETRN (A galactic cosmic-ray transport code). Hampton, Va: Langley Research Center, 1992.

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L, Shinn Judy, e United States. National Aeronautics and Space Administration. Scientific and Technical Information Program, a cura di. Fully energy-dependent HZETRN (A galactic cosmic-ray transport code). [Washington, DC]: National Aeronautics and Space Administration, Office of Management, Scientific and Technical Information Program, 1992.

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Capitoli di libri sul tema "Cosmic-ray transport"

Bindi, Veronica, Mercedes Paniccia e Martin Pohl. "Particle Transport". In Cosmic Ray Physics, 109–20. Boca Raton: CRC Press, 2023. http://dx.doi.org/10.1201/9781003181385-6.

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Schlickeiser, Reinhard. "Interplanetary Transport of Cosmic Ray Particles". In Cosmic Ray Astrophysics, 383–89. Berlin, Heidelberg: Springer Berlin Heidelberg, 2002. http://dx.doi.org/10.1007/978-3-662-04814-6_15.

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Giacalone, Joe. "Cosmic-Ray Transport Coefficients". In Cosmic Rays in the Heliosphere, 351–63. Dordrecht: Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-017-1189-0_20.

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Schlickeiser, Reinhard. "Acceleration and Transport Processes of Cosmic Rays". In Cosmic Ray Astrophysics, 365–81. Berlin, Heidelberg: Springer Berlin Heidelberg, 2002. http://dx.doi.org/10.1007/978-3-662-04814-6_14.

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Schlickeiser, Reinhard. "Test Particle Approach 1. Hierarchy of Transport Equations". In Cosmic Ray Astrophysics, 293–312. Berlin, Heidelberg: Springer Berlin Heidelberg, 2002. http://dx.doi.org/10.1007/978-3-662-04814-6_12.

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Schlickeiser, Reinhard. "Test Particle Approach 2. Calculation of Transport Parameters". In Cosmic Ray Astrophysics, 313–64. Berlin, Heidelberg: Springer Berlin Heidelberg, 2002. http://dx.doi.org/10.1007/978-3-662-04814-6_13.

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Giacalone, Joe. "Cosmic-Ray Transport and Interaction with Shocks". In Cosmic Rays in the Heliosphere, 73–88. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4614-9200-9_7.

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Yan, Huirong. "Cosmic Ray Transport in Turbulent Magnetic Field". In Astrophysics and Space Science Library, 253–81. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-662-44625-6_10.

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Bütikofer, R. "Cosmic Ray Particle Transport in the Earth’s Magnetosphere". In Astrophysics and Space Science Library, 79–94. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-60051-2_5.

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Hick, P., G. Stevens e J. van Rooijen. "The Maximum Entropy Principle in Cosmic Ray Transport Theory". In Astrophysics and Space Science Library, 355–58. Dordrecht: Springer Netherlands, 1986. http://dx.doi.org/10.1007/978-94-009-4612-5_43.

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Atti di convegni sul tema "Cosmic-ray transport"

Bramlitt, Edward. "Solar Proton Transport to Earth". In 35th International Cosmic Ray Conference. Trieste, Italy: Sissa Medialab, 2017. http://dx.doi.org/10.22323/1.301.0118.

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Ptsukin, Vladimir S. "Cosmic ray transport in the Galaxy". In Acceleration and transport of energetic particles observed in the heliosphere (ACE-2000 symposium). AIP, 2000. http://dx.doi.org/10.1063/1.1324344.

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Vittino, Andrea, Carmelo Evoli e Daniele Gaggero. "Cosmic-ray transport in the heliosphere with HELIOPROP". In 35th International Cosmic Ray Conference. Trieste, Italy: Sissa Medialab, 2017. http://dx.doi.org/10.22323/1.301.0024.

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Yanasak, N. E. "Abundances of the cosmic ray β-decay secondaries and implications for cosmic ray transport". In Acceleration and transport of energetic particles observed in the heliosphere (ACE-2000 symposium). AIP, 2000. http://dx.doi.org/10.1063/1.1324346.

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Reichherzer, Patrick, Julia Becker Tjus, Mario Hörbe, Ilja Jaroschewski, Wolfgang Rhode, Marcel Schroller e Fabian Schüssler. "Cosmic-ray transport in blazars: diffusive or ballistic propagation?" In 37th International Cosmic Ray Conference. Trieste, Italy: Sissa Medialab, 2021. http://dx.doi.org/10.22323/1.395.0468.

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Reimer, Olaf, Ralf Kissmann, Felix Niederwanger e Andrew W. Strong. "Anisotropic Diffusion in Galactic Cosmic Ray transport using PICARD". In 35th International Cosmic Ray Conference. Trieste, Italy: Sissa Medialab, 2017. http://dx.doi.org/10.22323/1.301.0480.

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Peretti, Enrico, Giovanni Morlino, Pasquale Blasi e Felix Aharonian. "Cosmic ray transport in starburst galaxies and possible observables". In 36th International Cosmic Ray Conference. Trieste, Italy: Sissa Medialab, 2019. http://dx.doi.org/10.22323/1.358.0382.

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TAUTZ, ROBERT C. "RECENT PROGRESS IN DESCRIBING COSMIC RAY TRANSPORT". In Proceedings of the MG11 Meeting on General Relativity. World Scientific Publishing Company, 2008. http://dx.doi.org/10.1142/9789812834300_0064.

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Verkhoglyadova, Olga P. "Cosmic ray transport in a vortex flow". In PHYSICS OF THE OUTER HELIOSPHERE. AIP, 2004. http://dx.doi.org/10.1063/1.1809524.

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Dettmar, Ralf-Juergen, Volker Heesen, Arpad Miskolczi e Yelena Stein. "New constraints on galactic CRE transport from radio continuum observations". In 36th International Cosmic Ray Conference. Trieste, Italy: Sissa Medialab, 2019. http://dx.doi.org/10.22323/1.358.0237.

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Rapporti di organizzazioni sul tema "Cosmic-ray transport"

Ptuskin, V. S., Igor V. Moskalenko, F. C. Jones, A. W. Strong e V. N. Zirakashvili. Dissipation of Magnetohydrodynamic Waves on Energetic Particles: Impact on Interstellar Turbulence and Cosmic Ray Transport. Office of Scientific and Technical Information (OSTI), gennaio 2006. http://dx.doi.org/10.2172/876043.

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