https://biblio.ugent.be/publication/685594/file/1130605.pdf

Review of Particle Physics

The advent of ultraintense laser pulses generated by the technique of chirped pulse amplification (CPA) along with the development of high-fluence laser materials has opened up an entirely new field of optics. The electromagnetic field intensities produced by these techniques, in excess of ${10}^{18}\phantom{\rule{0.3em}{0ex}}\mathrm{W}∕{\mathrm{cm}}^{2}$, lead to relativistic electron motion in the laser field. The CPA method is reviewed and the future growth of laser technique is discussed, including the prospect of generating the ultimate power of a zettawatt. A number of consequences of relativistic-strength optical fields are surveyed. In contrast to the nonrelativistic regime, these laser fields are capable of moving matter more effectively, including motion in the direction of laser propagation. One of the consequences of this is wakefield generation, a relativistic version of optical rectification, in which longitudinal field effects could be as large as the transverse ones. In addition to this, other effects may occur, including relativistic focusing, relativistic transparency, nonlinear modulation and multiple harmonic generation, and strong coupling to matter and other fields (such as high-frequency radiation). A proper utilization of these phenomena and effects leads to the new technology of relativistic engineering, in which light-matter interactions in the relativistic regime drives the development of laser-driven accelerator science. A number of significant applications are reviewed, including the fast ignition of an inertially confined fusion target by short-pulsed laser energy and potential sources of energetic particles (electrons, protons, other ions, positrons, pions, etc.). The coupling of an intense laser field to matter also has implications for the study of the highest energies in astrophysics, such as ultrahigh-energy cosmic rays, with energies in excess of ${10}^{20}\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$. The laser fields can be so intense as to make the accelerating field large enough for general relativistic effects (via the equivalence principle) to be examined in the laboratory. It will also enable one to access the nonlinear regime of quantum electrodynamics, where the effects of radiative damping are no longer negligible. Furthermore, when the fields are close to the Schwinger value, the vacuum can behave like a nonlinear medium in much the same way as ordinary dielectric matter expanded to laser radiation in the early days of laser research.

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Optics in the relativistic regime

http://absimage.aps.org/image/DAMOP12/MWS_DAMOP12-2012-000066.pdf

Optics in the Relativistic Regime

We survey the theory and experimental tests for the propagation of cosmic rays in the Galaxy up to energies of 10 15 eV. A guide to the previous reviews and essential literature is given, followed by an exposition of basic principles. The basic ideas of cosmic-ray propagation are described, and the physical origin of its processes is explained. The various techniques for computing the observational consequences of the theory are described and contrasted. These include analytical and numerical techniques. We present the comparison of models with data, including direct and indirect—especially γ-ray—observations, and indicate what we can learn about cosmic-ray propagation. Some important topics, including electron and antiparticle propagation, are chosen for discussion.

/pdf/cosmic-ray-propagation-and-interactions-in-the-galaxy-52wrtrud7h.pdf

Cosmic-Ray Propagation and Interactions in the Galaxy

We describe a method for the numerical computation of the propagation of primary and secondary nucleons, primary electrons, and secondary positrons and electrons. Fragmentation and energy losses are computed using realistic distributions for the interstellar gas and radiation fields, and diffusive reacceleration is also incorporated. The models are adjusted to agree with the observed cosmic-ray B/C and 10Be/9Be ratios. Models with diffusion and convection do not account well for the observed energy dependence of B/C, while models with reacceleration reproduce this easily. The height of the halo propagation region is determined using recent 10Be/9Be measurements as >4 kpc for diffusion/convection models and 4-12 kpc for reacceleration models. For convection models, we set an upper limit on the velocity gradient of dV/dz < 7 km s-1 kpc-1. The radial distribution of cosmic-ray sources required is broader than current estimates of the supernova remnant (SNR) distribution for all halo sizes. Full details of the numerical method used to solve the cosmic-ray propagation equation are given.

/pdf/propagation-of-cosmic-ray-nucleons-in-the-galaxy-4ojngwoeg9.pdf

Propagation of Cosmic-Ray Nucleons in the Galaxy

Editor's preface. I. The astrophysics of cosmic rays (general review). II. General information on cosmic rays and on the interstellar medium. III. The proton-nuclear component of cosmic rays in the Galaxy. General questions. Chemical and isotopic composition. IV. Cosmic rays of ultrahigh energies. V. The electron component of cosmic rays and radio astronomy. VI. Gamma-ray astronomy (some questions). VII. Gamma-ray astrophysics of very high and ultrahigh energies. VIII. High-energy neutrino astronomy. IX. Propagation of cosmic rays in the interstellar medium. X. Acceleration mechanisms of cosmic rays. References. Index.

Astrophysics of Cosmic Rays

The spectra of high-energy protons and nuclei accelerated by supernova remnant (SNR) shocks are calculated, taking into account magnetic field amplification and Alfvenic drift both upstream and downstream of the shock for different types of SNRs during their evolution. The maximum energy of accelerated particles may reach 5 x 10{sup 18} eV for Fe ions in Type IIb SNRs. The calculated energy spectrum of cosmic rays after propagation through the Galaxy is in good agreement with the spectrum measured at the Earth.

https://iopscience.iop.org/article/10.1088/0004-637X/718/1/31/pdf

Spectrum of Galactic Cosmic Rays Accelerated in Supernova Remnants

The instability in the cosmic-ray precursor of a supernova shock moving in interstellar medium is studied. The level of magnetohydrodynamic turbulence in this region determines the maximum energy of particles accelerated by the diffusive shock acceleration mechanism. A high efficiency of cosmic ray acceleration is accepted, and the consideration is not limited by the case of weak turbulence. It is assumed that Kolmogorov-type nonlinear wave interactions together with the ion-neutral collisions restrict the amplitude of the random magnetic field. As a result, the maximum energy of accelerated particles strongly depends on the age of the supernova remnant. The maximum energy can be as high as ∼10 17 Z eV in young supernova remnants and falls to about ∼10 10 Z eV at the end of the Sedov stage. Thus the standard estimate of maximum particle energy based on the Bohm limit calculated for the interstellar magnetic field strength is not justified in this case. This finding may explain why supernova remnants with age of more than a few thousand years are not prominent sources of very high energy gamma-rays.

/pdf/limits-on-diffusive-shock-acceleration-in-supernova-remnants-3zu4x2xhye.pdf

Limits on diffusive shock acceleration in supernova remnants in the presence of cosmic-ray streaming instability and wave dissipation

This paper reviews the present state of the problem of the origin of cosmic rays Primary attention is paid to galactic diffusion models with a halo, and questions of cosmic-ray chemical composition, electron component, and synchrotron galactic radioemission The authors' conclusion is that models with a large halo with a characteristic cosmic-ray age ${T}_{\mathrm{cr}}\ensuremath{\sim}{10}^{8}$ years are confirmed by radio data, and at least do not contradict the information on cosmic-ray chemical composition The paper also deals with the problems of anisotropy, plasma phenomena in cosmic rays, and the prospects of gamma-ray astronomy

On the Origin of Cosmic Rays: Some Problems in High-Energy Astrophysics

In an attempt to understand the source and propagation of Galactic cosmic rays, we have employed the modified weighted slab technique along with recent values of the relevant cross sections to compute primary to secondary ratios including B/C and sub-Fe/Fe for different Galactic propagation models. The models that we have considered are the disk-halo diffusion model, the dynamical halo wind model, the turbulent diffusion model, and a model with minimal reacceleration. The modified weighted slab technique will be briefly discussed and a more detailed description of the models will be given. We will also discuss the impact that the various models have on the problem of anisotropy at high energy and discuss what properties of a particular model bear on this issue.

https://iopscience.iop.org/article/10.1086/318358/pdf

Vladimir Ptuskin

Papers

Astrophysics of Cosmic Rays

Spectrum of Galactic Cosmic Rays Accelerated in Supernova Remnants

Limits on diffusive shock acceleration in supernova remnants in the presence of cosmic-ray streaming instability and wave dissipation

On the Origin of Cosmic Rays: Some Problems in High-Energy Astrophysics

The Modified Weighted Slab Technique: Models and Results