[en] The anomalies in the abundances and energy spectra of low-energy cosmic rays (He, N, O and Ne) are considered. The review of experimental data is given. The anomalous spectra are detected to the end of 1977. The anomalous abundances, the positive radial gradient and the modUlation effects inducate a nonsolar origin for low-energy particles of cosmic rays. Various possible models of solar origin, galactic origin or acceleration of these particles by interplanetary shock waves are discussed. The interplanetary origin is considered to be the most likely source of the anomalous component of cosmic rays

[en] Mean ionic charge of iron in He-3-rich solar flares and the average mean charge of silicon for 23 He-3-rich periods during the time interval from September 1978 to October 1979 were determined. It is indicated that the value of the mean charge state of silicon is higher than the normal flare average by approximately 3 units, and in perticular it is higher then the value predicted by resonant heating models for He-3-rich solar flares

[en] A survey of the approx. 1 MeV/nucleon heavy ion abundances in 66 He³-rich solar particle events was performed using the Max-Planck-Institut/University of Maryland and Goddard Space Flight Center instruments on the ISEE-3 spacecraft. The observations were carried out in interplanetary space over the period 1978 October through 1982 June. Earlier observations were confirmed which show an enrichment of heavy ions in HE3-rich events, relative to the average solar energetic particle composition in large particle events. For the survey near 1.5 MeV/nucleon the enrichments compared to large solar particle events are approximately He4:C:O:Ne:Mg:Si:Fe = 0.44:0.66:1.:3.4:3.5:4.1:9.6. Surprising new results emerging from the present broad survey are that the heavy ion enrichment pattern is the same within a factor of approx. 2 for almost all cases, and the degree of heavy ion enrichment is uncorrelated with the He³ enrichment. Overall, the features established appear to be best explained by an acceleration mechanism in which the He³ enrichment process is not responsible for the heavy ion enrichment, but rather the heavy ion enrichment is a measure of the ambient coronal composition at the sites where the He³-rich events occur

[en] An unusual spectral feature and anomalously large abundance of helium between 0.6 and approximately 2 MeV per nucleon observed during the most quiet time periods in 1974 and 1975 indicate the presence of low-energy helium of an unknown origin. Alphas below 0.6 MeV per nucleon and protons below 1.5 MeV have an E to the minus 1.8 power spectrum, and the proton to alpha ratio is about 30. These particles, of 1 MeV or less, are found to be emitted continuously by the Sun, even during its most inactive periods

[en] The energetic particle population in the heliosphere is highly variable in space and time, intensity, energy, and composition. Over the last decades advanced instrumentation onboard many spacecraft extended our ability to explore the energetic particle populations in the inner and outer heliosphere. We are now able to measure intensity-time profiles and anisotropies, energy spectra, elemental and isotopic abundances, and the ionic charge of particles over an extended energy range of ∼0.1 to 100 MeV/nuc and for a large dynamic range of particle intensities. These measurements provide crucial information for understanding the sources of the particle populations and the acceleration and propagation processes involved. In this paper we provide an overview of the various particle populations observed in the heliosphere, with emphasis on particles accelerated at the Sun, at interplanetary shocks, in co-rotating interactions regions, and in the outer heliosphere. (authors)

[en] Short communication

[en] The ionic mass and charge composition of the suprathermal (10-230 keV/e) population of the plasma sheet has been measured using the Suprathermal Energy Ionic Charge Analyzer (SULEICA) on AMPTE/IRM before and after a substorm onset on April 8, 1985. Simultaneously with the substorm onset and strong earthward plasma flows, a flux increase of the suprathermal ions and a significant hardening of the spectra are observed that are most pronounced for O(+). The enhancement ratios can be best organized in terms of energy per charge. The observations are interpreted as an indication of particle acceleration by electric fields and additional injection of ionospheric plasma into the plasma sheet after substorm onset. 12 references

[en] The intensity--time behavior for protons and helium, as well as for carbon, oxygen, and iron ions, was measured following the 1974 September 19 solar flare for energies between 0.5 and approximately 5 MeV per nucleon. The profiles displayed a time dispersion which is inversely proportional to velocity for each individual species. In addition, at a given velocity the time dispersion also depended on the charge to mass ratio of the ion. On the basis of this latter dependence, it was concluded that, while carbon and oxygen are essentially fully stripped, iron nuclei are not, having an effective charge Q = 10 +- 5. The observed dispersion cannot be explained by purely rigidity-dependent diffusive propagation

[en] Using current modulation theory for the transport of low-energy cosmic ray particles and the model of Fisk (1976a) for their acceleration by transit time damping large-scale field variations in the outer solar system, we construct a set of parameters which reproduce the quiet time spectra of He, O, N, and Ne as observed at 1 AU during the time period 1973--1975. With an analytic approximation for the acceleration and a numerical solution for the steady state spherical symmetric transport equation, both the observed spectral shapes and the relative intensities for He, O, N, and Ne can be fitted simultaneously remarkably well. For the fit, one set of parameters is used: the acceleration rate, the size of the heliosphere, and the total number of particles injected. To obtain this number, it is assumed that independent of the species, the same fraction of the particles, which are ionized inside the heliosphere (by UV radiation and charge exchange with solar wind particles), participate in the acceleration. For the calculation of the production rate of singly ionized ions the ionization rates provided by Siscoe and Mukherjee (1972) are used, and the solar system abundances of A. G. W. Cameron (unpublished manuscript, 1973) are assumed for the composition of the neutral wind

[en] A summary is given of recent results from the direct determination of the charge states of He, C, O, and Fe. These results are used in discussing compositional variations during individual solar particle events. It is shown that ratio changes by a factor of approximately 10 during the onset phase of solar particle events can be explained not only by rigidity-dependent interplanetary propagation but also by rigidity-dependent diffusive propagation in the corona. Increasing experimental evidence is seen that other processes, such as compositional variations at the source and discontinuities of the interplanetary magnetic field separating two different particle populations, may be important. No common explanation is seen for all the variations, and it is concluded that each must be investigated on its own