About Cosmic Ray Sources in Galaxy

Physics of Atomic Nuclei - In the last two decades the new experimental data on cosmic rays concerning energy spectra in a wide energy range up to 10 $${}^{14}$$ eV, isotropy, ratio of positron...     

Suprathermal <Superscript>4</Superscript>He,O, and Fe ions at 1 AU in the quiet time of 2006–2012

The energy spectra of ⁴He, O, and Fe ions with energies of 0.04–2 MeV/nucleon, obtained by the ULEIS device on board the ACE satellite in the quiet time of 2006–2012, are analyzed. The obtained spectra of suprathermal ions from coronal holes were approximated by either a power function or a combination of a power and an exponential function. The approximation of 98 spectra yielded 2 < γ < 6, which could indicate different conditions in regions of particle acceleration in solar wind streams from coronal holes.     

Kinetics of isothermal nucleation in a supercooled iron melt

An isothermal kinetic diagram for the beginning of homogeneous nucleation is constructed using the molecular-dynamics model of an instantaneously supercooled iron melt near the icosahedral percolation transition temperature identified with the glass transition temperature T _g . This diagram is compared with the theoretical one calculated using quantitative information obtained by analyzing the kinetics of the initial stage of growth of supercritical nuclei at temperatures higher than T _g . A satisfactory coincidence of the theoretical curve with computer simulation data at temperatures higher than T _g and substantial disagreement with these data below T _g , where crystallization is necessarily preceded by the formation of an icosahedral percolation cluster, demonstrate the substantive influence of an icosahedral substructure on the nucleation rate predicted by the classical theory.     

Nondestructive diagnostics of charged particle beams in accelerators

The basic techniques for nondestructive diagnostics and detection of losses of charged particle beams used in accelerator engineering are reviewed. The data provided may help choose the systems for diagnostics and detection of losses of beams and give a qualitative picture of the operation principles of such devices. Quantitative characteristics that define the limits of applicability of each diagnostic technique are outlined.     

GRIF-1 experiment on board the SPEKTR/MIR orbital complex: Study of solar X-ray,gamma-ray,and neutron flares and correlation of magnetosphere-charged particle fluxes with solar activity

The SPEKTR module of the MIR orbital station was launched in May 1995. The multipurpose experiment was based on the GRIF-1 research complex consisting of an oriented X-ray spectrometer, a spectrometer of gamma-quanta and neutrons, a spectrometer of electrons and protons with a large geometrical factor, and a spectrometer of electrons, protons, and nuclei with a small geometrical factor. The solar geophysical aspects of the experiment included the measurements of spectral and temporal parameters of solar hard electromagnetic (0.01–50 MeV) and neutron (>20 MзB) radiation, the study of spectral, temporal, and spatial characteristics of energetic electrons (0.04–1.5 MeV), protons, and nuclei (1–200 MeV/nucleon) in the circumterrestrial space, as well as the correlations of these parameters with solar activity phenomena.     

Some specific features of the decay of solar energetic-particle events

Most events involving solar particles with energies of several megaelectronvolts exhibit exponential decays. Comparison of the observed characteristic decay times τ_obs with the corresponding values τ_theor obtained within theoretical models taking into account convective transport of particles and their adiabatic deceleration showed that the values of τ_theor, depending on the surrounding plasma parameters, are reasonably close (within 25%) to τ_obs in about 50% cases where the solar wind speed V remains constant.