D. A. Zhuravlev

The Charge State of the Anomalous Component of Cosmic Rays

The ionic charge state of anomalous cosmic-ray oxygen has been determined by comparing measurements obtained inside the magnetosphere on a series of Cosmos satellite flights with simultaneous observations outside the magnetosphere from IMP 8 and ICE. We find a mean charge state of 0.9 ^(+0.3)_(-0.2) for ~10 MeV nucleon^(-1) anomalous oxygen, consistent with the model of Fisk, Kozlovsky, & Ramaty, in which the anomalous cosmic rays originate from the neutral component of the local interstellar medium. This same approach gives results consistent with a mean charge of +7 for solar energetic oxygen ions.

Measurements of solar heavy ions inside the earth's magnetosphere

Abstract Stacks of cellulose nitrate and cellulose triacetate plastic nuclear track detectors were exposed on a russian satellite in a low earth orbit during the solar particle events in October 1989. Extremely high fluences of solar particles with nuclear charges equal to or greater than 6 were registered. In CTA a charge identification for Z= 8–14 with a resolution of 0.5 charge units was achieved. Energy spectra and arrival directions of the detected particles were measured in both detector materials. The distribution of the arrival directions for ions in CTA shows a significant contribution of particles impinging from below the horizon.

Determining the charge states of solar energetic ions during large geomagnetic storms

We give a progress report on a new method of measuring the mean ionic charge states of solar energetic particles (SEPs) and apply this method to oxygen ions at energies of ∼10 MeV/nucleon. We compare simultaneous flux measurements inside and outside the magnetosphere to determine the geomagnetic transmission and use this result to find the corresponding mean ionic charge state. The key to this method is to determine the dependence of the geomagnetic transmission function on the mean ionic charge state of the ions. We report here the results of a new technique to calculate the geomagnetic transmission function, which attempts to account for the cutoff suppression caused by the geomagnetic activity which often accompanies SEP events.

Recent observations of anomalous cosmic rays made with solid track detectors

Abstract A few exposures of CN-85 detectors on Earth-orbiting satellites in the period 1993–1994 show evidence for the reappearance of the radiation belt from geomagnetically trapped anomalous cosmic ray ions.

Detecting Be-7 in the orbits of the COSMOS series spacecraft during solar cycle 24

Experiments to detect the radionuclide Be-7 in the orbits of the COSMOS series satellites at altitudes of 200–400 km continued in the period 2007–2012. Measurements of Be-7 radioactivity during solar proton events and quiet periods of the Sun confirm the correlation found earlier between observed Be-7 concentrations and the magnitude of the flux of energetic solar protons near the Earth.

On the role of convection in propagation of ions of anomalous cosmic rays in the heliosphere

546 The standard model of solar modulation of cosmic ray fluxes considers transport of particles from the heliosphere boundary to the Earth under the action of processes of diffusion in turbulent magnetic fields, convection by counter motion of the fields frozen into the solar wind, and adiabatic deceleration in the field expanding while moving from the Sun. Drift theories improve standard models of modulation by adding consideration of the influence of magnetic field con figuration and its polarity on the motion of charged particles in the heliosphere. According to the drift the ories, changes in the diffusion coefficient are less important in formation of 11 year cycle than changes in the slope and shape of the neutral current sheet sep arating magnetic fields of the northern and southern hemispheres of the Sun. For example, it was shown in [1] that at a change of the α angle of the slope of the neutral current sheet to the equatorial plane from 10° to 30°, the intensity of particles near the Earth changed from its value in the solar activity (SA) mini mum to the value in the SA maximum. In this commu nication we would like to show visually the role of con vection in propagation of ions of anomalous cosmic rays using that feature of the current 23rd SA cycle, which is consists in the fact that during the SA mini mum in 2007–2008 the slope of the neutral sheet was large.

On the possibility of existence of an additional source of anomalous cosmic rays outside the solar system

On the basis of experimental data obtained at exposure of solid-state track detectors in the magnetosphere of the Earth during solar flares and in quiet Sun periods, an estimate of possible contribution of singly charged oxygen ions to the flare particle fluxes is made. A possibility is considered of the appearance in the vicinity of the solar system of singly ionized oxygen ions generated on stars.

Possible Use of the Earth's Magnetic Field for Determination of the Electric Charge Sign of Cosmic Ray Particles with a Magnetic Rigidity of 103 GV and Above

We consider a variant of the use of the Earths magnetic field, which allows one to separate particles with different electric charge at a magnetic rigidity of 103 GV and above by applying advanced experimental technology.

Anomalous cosmic ray carbon and oxygen tracks in CN-Kodak

For observation of low energy cosmic ray particles we used CN-Kodak nuclear track detectors on Cosmos satellites. In solar quiet periods during solar minima conditions the detectors registered anomalous cosmic rays (ACRs). The ACRs are characterized by flux enhancements of several elements and it is known that the carbon enhancement is small compared with that of oxygen. In all of our quiet-time exposures the relation between carbon and oxygen was extremely small (C/O ~ 0.03). But in two quiet-time periods of 14.03.96-11.06.96 and of 15.12.97-14.04.98 we have identified many tracks as carbon in a L-R diagram. As a result the observed C/O ratio appears to be more than 0.5, whereas other experiments show no evidence of enhanced flux of carbon during these periods. The reason for the unexpected response of CN-Kodak is discussed.

The energy spectra of anomalous oxygen at the time of two successive solar minima

Abstract The energy spectra of anomalous oxygen have been determined from nuclear track detectors exposed aboard the Earth-orbiting satellites and altitudes ranging from ∼250–400 km in two consecutive solar minimum periods of 1986–1987 and 1994–1995 with opposite polarity of the solar magnetic field. A comparison of the spectra shows no contradiction to current drift models.