The role of Coulombian energy losses in cosmic ray physics is generally over simplified by using the Bethe-Block formulation which does not depend explicitly on the temperature of the medium. The role of low energy particles is usually neglected, as a result of the over estimation of losses when the temperature of the medium is ignored. A deep analysis of Coulombian losses may raise the importance of these particles in the dynamics of the Galaxy. In fact, the deceleration of these particles is determined by charge interchange processes with the target ions and electrons, which energy dependence is roughly the inverse of ionisation losses. Even high energy particles may be subject to this kind of deceleration if the temperature is very high. The consideration of Coulombian losses through all energy ranges with explicit dependence on the temperature has been discussed by Perez and Lara (1979): a fully ionized medium of hydrogen has been assumed to prevail in most of cosmic ray sources. One kind of the implications is the determination of particle composition. It is claimed that a given kind of ion is preferentially accelerated or depleted depending on whether the acceleration is higher or lower than the deceleration rate at the beginning of the acceleration of thermal material. Species which undergo depletion are accelerated only if their energy is higher than that for which both rates are equated (Ec,E′c and E′c′) in such a way that only those of the hot tails of their thermal distributions are effectively accelerated. These will appear depleted relative to other species which are free accelerated because their deceleration rates at low energies are lower than the acceleration rate. It can be noted in the next figures, that if both rates would not intersect at the beginning of the acceleration, they would not join at higher energies because the acceleration rate grows faster with energy than the deceleration rate. Three arbitrary acceleration rates are used for illustration: Fermi-2nd order (αβW), Betatron or adiabatic heating (αβ2W) and shock wave acceleration (αW), where α, β and W are the efficiency, the particles velocity and the total energy per nucleon respectively. In Fig. 1 it can be seen that this selective acceleration relative to Coulombian losses is defined at different energy levels depending on the kind of acceleration involved. Since the main effect of the temperature on the losses at the beginning of the acceleration is through the local charge states of the ions, the sequence of energy losses among different species is highly assorted. This is translated in a great amount of possibilities of particle enhancements and depletions according to the temperature of the source and the kind of acceleration operating therein. If particles under go acceleration in a fully stripped state, the sequence of losses at all energy levels is such that the heavy elements are depleted in relation with the lighter ones; same is the situation, what-ever the initial charge state, for high energy particles in the range of ionisation. It may be concluded, on basis to the observational enhancement of heavy cosmic rays, that hot regions are not likely sources, and that acceleration initiates from thermal energies. On Fig. 2 it is illustrated the enhancement of Fe over 0 in solar flare conditions, on basis to the charge states as given by Jordan (1969). If α < 2.71 s−1 both elements would be depleted, whereas if α>3.45 s−1 both would be preferentially accelerated.

High energy phenomena in the solar physics context, simply means solar flares. To be sure, the energies attained during flares are certainly not very impressive on a cosmic-ray scale. The most energetic particles belong the GeV range, the highest temperatures are of the order of 107 K, γ-ray emission is occasional and the total energy emitted remains below 1033 ergs for all the flares so far observed. Apart from an absolute energy scale, flares are also energetically irrelevant on a solar scale. In fact in a large flare a few units in 1032 ergs are emitted, with a total duration of about one hour and a total surface area involved of a few units in 10−4 of the solar surface. Recalling the values of the luminosity, L⊙ ≃ 4 × 1033 erg s−1 and the solar flux F⊙6.3 × 1010 erg cm−2s−1, we see that

Two processes are discussed which violate the frozen-in condition in a highly conducting plasma, reconnection and the auroral acceleration process. The first applies to situations in which . It plays an important role in the interaction of the solar wind with the Earth's magnetic field and controls energy input into as well as energetic particle release from the magnetosphere. Detailed in situ studies of the process on the dayside magnetopause reveal its transient and small-scale nature. The auroral acceleration process occurs in the low magnetosphere (β « 1) and accompanies sudden releases of magnetic shear stresses which exist in large-scale magnetospheric-ionospheric current circuits. The process is interpreted as a kind of breaking. The movements of the magnetospheric plasma which lead to a relief of the magnetic tensions occur in thin sheets and are decoupled along the magnetic field lines by parallel electric potential drops. It is this voltage that accelerates the primary auroral particles. The visible arcs are then traces of the magnetic breaking process at several 1000 km altitude.

The possible mechanism of helium isotopes separation in the solar atmosphere due to plasma effects have been proposed by G.E. Kocharov (1977), I. Ibragimov and G. Kocharov (1977). The cycle of papers: G. Kocharov and L. Kocharov (1978); L. Kocharov (1979 a,b,c,d, 1980); G. Kocharov, L. Kocharov and Yu. Charikov (1980) is devoted to the development of the theory and to the search of concrete model of corresponding physical processes in the solar plasma. Here we consider briefly the modern state of this problem.

Extensive measurements of the composition of energetic solar flare particles have revealed the frequent occurrence of solar flares with large enrichments of 3He and heavy ions compared to the composition of the solar atmosphere. The basic characteristics of these events can be summarized as follows:

1. – 3He/4He-ratios up to more than 1 are observed

2. – the 3He/4He-ratio increases with energy

3. – no comparable enhancement of 2H or 3H is found

4. – there is a strong correlation of 3He and heavy ion enrichment.

Sekido and Murakami (1958) proposed the existence of the heliosphere to explain the scattered component of the solar cosmic rays. The heliosphere of their conception is a spherical shell around the sun. The shell contains a highly-irregular magnetic field and serves to scatter the cosmic rays emitted by the sun. It thereby gives rise to an isotropic component of solar cosmic rays, following the maximum in the ground level enhancement (GLE). Meyer et al. (1956) showed that a similar picture applies to the GLE of 23 February 1956. They conclude that the inner and outer radii of the shell should be 1.4 AU and 5 AU respectively. They suggest that a shell is formed by the “pile-up” of the solar wind under pressure exerted by the interstellar magnetic field, as suggested by Davis (1955).