A Statistic Model for Galactic Cosmic Rays

Supposed that all of cosmic ray particles of energy below 3×10¹⁸eV are mainly originated and accelerated in an individual explosion of the galactic supernovae(SNs).By using an isotropic diffusion propagation model,non-steady state density of the iron nucleus is investigated.Considering the effect of extra-galactic cosmic rays and the variety of the galactic cosmic ray nuclei,the statistic model of galactic cosmic rays with a reasonable distribution of the SNs in space and time can account for the spectrum of cosmic ray in the energy range of 10¹²—10²⁰eV quitewell.     

Diffusion of cosmic rays in a model with interstellar turbulence damping due to interaction with energetic particles

A self-consistent model of galactic cosmic ray transport is considered. The resonance wave–particle interaction in this model causes a cascade of magnetosonic waves to decay in the interstellar medium. The calculated coefficient of diffusion of cosmic rays in the Galaxy has a characteristic minimum at an energy of several GeV/nucleon, which agrees with the empirical diffusion model of cosmic ray propagation.     

New Universal Cosmic-Ray Knee near a Magnetic Rigidity of 10 TV with the NUCLEON Space Observatory

Data from the NUCLEON space observatory give a strong indication of the existence of a new universal cosmic ray “knee”, which is observed in all groups of nuclei, including heavy nuclei, near a magnetic rigidity of about 10 TV. Universality means the same position of the knee in the magnetic rigidity scale for all groups of nuclei. The knee is observed by both methods of measurement of particles energy implemented in the NUCLEON observatory—the calorimetric method and the kinematic method Kinematic Lightweight Energy Meter. This new cosmic ray knee is probably connected with the limit of acceleration of cosmic rays by some generic or nearby source of cosmic rays.     

DIMENSIONAL METHOD TO SOLVE THE DIFFUSION CONVECTION EQUATION OF SOLAR COSMIC RAYS

Physical processes of the propagation of the solar cosmic rays in the interplanetary space include the diffusion in interplanetary disordered magnetic fields and the convection in solar winds. Dimensional method can be applied to solve those equations convertible into Bessel equation, the results obtained are identical with those solved by the commonly used separate variable method. In order to derive an analytic solution to the diffusion convection equation in an unbounded, uniform medium, two dimensionless parameters reflecting the diffusion and convection characteristics of the particles are introduced. In the diffusion dominated case, the solution is similar in form to the diffusion of a source moving with the convection velocity and is modified by another convection term, which can be expanded into a power series of the convection parameter with coefficients composed of the generalized hypergeometric function series of the diffusion parameter. This solution has a clear physical meaning, and can suitably be used in the discussion of the rise phase characteristics of the solar cosmic rays from medium to high energies （E_p≥10¹ MeV）.     

The theory of particle diffusion in a strong random magnetic field with an allowance for higher multipole moments of the distribution function

The kinetic equation including a small-scale collisional integral for the particles propagating in a strong random and regular magnetic field [29] is solved by expanding the distribution function into series in spherical harmonics of the particle momentum angles. Using methods of the quantum theory of the angular moment [41], the equations for higher multipole moments of the distribution function in the space of momentum angles are derived and solved in the stationary case for the galactic cosmic rays in interplanetary space. The observed amplitudes and phases of the diurnal variation harmonics can be explained using the results of measurements of the interplanetary magnetic field performed on board the Ulysses spacecraft [12–14] and other satellites [45, 46] with an allowance for redistribution of the interplanetary and interstellar magnetic field lines. The spatial structure of the convection and diffusion fluxes of the galactic cosmic rays is refined. Formulas taking into account a change in the Earth’s axis tilt relative to the direction toward the Sun are derived, which allow the annual changes in contributions to the diurnal variation harmonics to be determined. The equation of diffusion taking into account the 2nd harmonic is obtained, and the contribution of this effect to the relative particle density in the cosmic rays in a spherically symmetric case is analyzed.     

The surfatron acceleration of cosmic rays in the galactic plasma

The optimum conditions for a prolonged holding of charged particles resonantly trapped from the galactic plasma by nonlinear waves and for the acceleration of these particles to high energies by the surfatron mechanism are established. The density of particles trapped by the plasma waves of large amplitude and by the quasitransverse magnetosonic shock waves is estimated. Various reasons leading to possible breakage of the process of surfatron acceleration of cosmic rays in the Galaxy are considered. Within the framework of the surfatron acceleration mechanism, galactic cosmic rays originate predominantly from the interstellar plasma and their energy spectrum is formed in two stages. In the first stage, some of the galactic plasma particles are accelerated from thermal energies to 10¹⁵ eV/nucleon; in the second stage, the cosmic rays may continue gaining energy up to 10¹⁹ eV/nucleon and above.     

Implications on cosmic ray injection and propagation parameters from Voyager/ACE/AMS-02 nucleus data

We study the propagation and injection models of cosmic rays using the latest measurements of the boron-to-carbon ratio and fluxes of protons, helium, carbon, and oxygen nuclei by the Alpha Magnetic Spectrometer and the Advanced Composition Explorer at top of the Earth, and the Voyager spacecraft outside the heliosphere. The Advanced Composition Explorer(ACE) data during the same time interval of the AMS-02 data are extracted to minimize the complexity of the solar modulation effect. We find that the cosmic ray nucleus data favor a modified version of the diffusion-reacceleration scenario of the propagation. The diffusion coefficient is, however, required to increase moderately with decreasing rigidity at low energies, which has interesting implications on the particle and plasma interaction in the Milky Way. We further find that the low rigidity( a few GV) injection spectra are different for different compositions. The injection spectra are softer for lighter nuclei. These results are expected to be helpful in understanding the acceleration process of cosmic rays.     

On the origin of cosmic rays and the value of fundamental length

It is suggested that the physical mechanism responsible for the acceleration of cosmic rays is due to the stochastic (or fluctuational) structure of space-time at small distances. A method of introducing fluctuations in a conformally flat Riemannian space-time metric due to ultrahigh energy particles is presented, from which a nonlinear dynamics of particles and equations for the electromagnetic field are obtained. The former admits the acceleration mechanism for cosmic-ray particles and the extreme energy increases during the evolution of the Universe. In our model the energy of the cosmic-ray particle and its radius (the effective Schwarzschild), the age of the universe, and the value of the fundamental length are connected with one another and are determined by a unified formula, Einstein's relation for the relativistic particle energy. It allows one to define experimentally the value of the fundamental length, which is l=1.56×10 ^–33 cm for the maximum proton energy observed in cosmic rays. The problem of the energy spectrum of the cosmic rays and the ratio of intensities of the electron component to the proton component at the same energy level are also discussed.On leave of absence from the Academy of Sciences, Mongolian People's Republic, Ulan-Bator, Mongolia.     

Cosmic rays in the Earth’s atmosphere

This paper presents a brief historical overview of studies of cosmic rays in the Earth’s atmosphere, which were initiated and led by S.N. Vernov for over 50 years. The main results of these studies that were obtained in recent decades are given. They include the study of the processes of generation and propagation of solar cosmic rays, the modulation of galactic cosmic rays in the heliomagnetosphere, and the role of cosmic rays in atmospheric processes.     

Primary cosmic ray composition at energies from 10<Superscript>17</Superscript> to 10<Superscript>18</Superscript> eV according to the EAS MSU array data

EAS MSU array data on the composition of primary cosmic rays at energies above 10₁₇ eV are analyzed. The problem of existence of a cosmic ray component that is not related to the conventional mechanism of formation of galactic cosmic rays is considered and the fraction of γ rays in primary cosmic rays is estimated.     

多气隙电阻板室的宇宙线测量结果

介绍了20多个多气隙电阻板室的宇宙线测量结果.测量所用的宇宙线平台可以同时测量同一个电阻板室的多个cell,其参考时间的时间分辨为70ps.在宇宙线的测量条件下,用国产材料制作的多气隙电阻板室的时间分辨可达到90ps.利用这套宇宙线测量系统,还对多气隙电阻板室的探测效率和cell间的相互串扰进行了研究.     

Possible acceleration of cosmic rays in a rotating system: Uehling-Uhlenbeck model

We illustrate the possible acceleration of cosmic rays passing through a kind of amplification channel (via diffusion modes of propagating plane-wave fronts) induced by a rotating system. Our analysis is mainly based on the quantum discrete kinetic model (considering a discrete Uehling-Uhlenbeck collision term), which has been used to study the propagation of plane (e.g., acoustic) waves in a system of rotating gases.     

Predicting dangerous radiation fluxes of solar cosmic rays on the basis of data from neutron monitors

We discuss the possibility of predicting dangerous radiation fluxes of solar cosmic rays (SCRs) with energies of tens to hundreds of MeV on the basis of data from neutron monitors located on the Earth’s surface. Neutron monitors record relativistic cosmic rays (energies of 0.5 to several GeV) with minimal delay, but the intensity of cosmic rays is low in the high-energy region and does not pose a serious radiation hazard. By determining the spectrum of cosmic rays at high energies, however, it is possible to forecast radiation dangerous particle fluxes of moderate energies with a lead time of several hours. Such forecasts are, however, possible only with data on the so-called delay component of relativistic cosmic rays.     

PLASTIC SCINTILLATOR RESPONSE TO CHARGED PARTICLES

Plastic scintillators with many advantages are widely used in particle physics. Researches on plastic scintillator response at both high energy and high electric charge are significant to the experiments in high energy physics and cosmic ray physics. In addition to many important astrophysical results, the high energy cosmic rays experiments at the University of Chicago accumulate data for plastic scintillator response to relativistic particles of high electric charges. This paper introduces the cosmic ray experiments mentioned above, presents data analysis results and the discusses the nonlinear response of plastic scintillators.     

Nonextensive thermal sources of cosmic rays

The energy spectrum of cosmic rays exhibits power-like behavior with a very characteristic ‘knee’ structure. We consider a possibility that such a spectrum could be generated by some specific nonstatistical temperature fluctuations in the source of cosmic rays with the ‘knee’ structure reflecting an abrupt change of the pattern of such fluctuations. This would result in a generalized nonextensive statistical model for the production of cosmic rays. The possible physical mechanisms leading to these effects are discussed together with the resulting chemical composition of the cosmic rays, which follows the experimentally observed abundance of nuclei.     

Spectra of Protons and Alpha Particles and Their Comparison in the NUCLEON Experiment Data

JETP Letters - The aim of the NUCLEON space experiment was to measure spectra of high-energy cosmic rays. Direct measurements of energy spectra of protons and nuclei of cosmic rays which allow...     

On the fractional derivative model of the transport of cosmic rays in the Galaxy

One of the models of the transport of cosmic rays in the Galaxy that is based on a fractional partial differential equation is criticized. A new model called the model of limited anomalous diffusion is proposed. Its main difference from the criticized model is that the finiteness of the velocity of particles is taken into account.     

Behavior of the intensity of galactic and anomalous cosmic rays in the outer heliosphere and large-scale electric fields

The behavior of the intensity of anomalous and galactic cosmic rays in the outer heliosphere is compared. The previous hypothesis, according to which the lowest energy galactic cosmic rays affected by large-scale electric fields far beyond the termination shock wave of the solar wind may contribute to the behavior of the anomalous component intensity, is analyzed.     

Extremely high energy cosmic rays

The evidence for the existence of cosmic rays with energies in excess of 10²⁰ eV is now overwhelming. There is so far no indication of the GZK cutoff in the energy spectrum at 5 × 10¹⁹ eV. This conclusion is not firm for lack of statistics. A cutoff would be expected if the sources of the cosmic rays were distributed uniformly throughout the cosmos. The sources of cosmic rays with energy above the GZK cutoff must be at a distance ≤ 100 Mpc, and if they are protons they are very likely to point to these sources. There are no easy explanations how known astrophysical objects can accelerate protons (or atomic nuclei) to these energies. This difficulty has led to speculation that there may be exotic sources such as topological defects which produce these energetic cosmic rays directly along with a copious supply of neutrinos of similar energy. The fluxes of these cosmic rays is very low and large instruments are required to observe them even with modest statistics. One such instrument, the Pierre Auger Observatory, is described. It is designed for all-sky coverage and the construction of its southern site will begin in Argentina in 1999.