B. A. Trubnikov

Current filaments in plasmas

Possible configurations of current filaments in Z-pinch and tokamak plasmas are analyzed. A thin current-carrying beam injected in a plasma should be surrounded by a halo of countercurrents, in which case the resulting configuration may resemble a tubular structure. A.B. Kukushkin and V.A. Rantsev-Kartinov pointed out the existence of specific plasma structures of the squirrel-cage type and interpreted them as “wild cables of solid-state nanotubes.” It is shown that these structures can also be attributed to the fundamental mode of the conventional magnetic filamentation in the form of a “hexagonal parquet.” Also, a study is made of the phenomena governing the pattern of plasma structures, namely, tearing filamentation, two types of longitudinal beam bunching, and self-organization of the filaments.

Induction mechanism of cosmic ray production and kinks in the cosmic ray spectrum

Two kinks are observed in the energy spectrum of galactic cosmic rays. It is shown that the entire spectrum can be described, to a good approximation, by a single formula obtained on the basis of the hypothesis that the particles are produced and accelerated in plasma pinches by an induction mechanism under the assumption that three hierarchical groups of currents are present—interstellar, galactic, and metagalactic.

Model of cosmic ray generation

It is shown that the two bends observed in the cosmic ray energy spectrum can be well approximated by equations derived by assuming that cosmic rays can be generated and accelerated in plasma pinches.

Change in cosmic-ray spectrum through the production of electron-positron pairs (analytical approach)

We consider the change in primordial cosmic-ray spectrum through the production of electron-positron pairs in collisions with cosmic microwave background radiation photons. We suggest using these results to estimate the distances to cosmic-ray sources.

Jets as accelerators of ultrahigh-energy cosmic ray particles

The model of a cosmic jet that operates in the regimes of an MHD nozzle and a unipolar inductor is considered. It is shown that the “solid-body” rotation (according to Ferraro’s law) of helical magnetic field lines should lead to an acceleration of a small fraction of the plasma particles to ultrarelativistic energies with a spectrum dq/dɛ ∼ ɛ−n and an index n close to its observed value of n ≈ 2.70–2.75.

Shock-wave and plasma-pinch mechanisms of galactic cosmic-ray production

Based on recent discoveries, we show that it is appropriate to complement the standard shock-wave model for the production of galactic cosmic rays by a plasma-pinch model. The latter describes well the production of high-energy cosmic rays, yields a simple formula for their intensity, and allows the threshold pattern of the knee-type kink in the secondary particle spectrum and a number of unusual phenomena observed above the threshold to be explained.

On the oscillations of the plasma atmosphere in gamma-ray bursts

One of the possible hypotheses implies that cosmic gamma-ray bursts can arise when two neutron stars or black holes merge together. These bursts sometimes continue for several tens of seconds, but the time dependence of their intensity often exhibits ∼102–103 almost periodic small peaks with a period of ∼10 ms. A model of oscillations in the lower plasma shell, which arises in cosmic gamma-ray bursts and is located near a neutron star, is proposed; the greater part of arising plasma in the form of an “upper” shell continues to expand into the surroundings. Other possible interpretations of periodicity of the “small peaks” are also analyzed.

Conservation law for the binormal momentum in the presence of charge drift in a magnetic field

It is well-known that the motion of a charged particle in a magnetic field is described by the drift approximation, in which it is assumed that the squared velocity of the particle and the magnetic moment of the Larmor circle are conserved. It is shown that to a first approximation a third conservation law is also satisfied: the unaveraged generalized momentum in the direction of the binormal to the reference flux line around which the particle rotates is conserved. This new conservation law makes it possible to determine additional fine details of the motion, specifically, the deflection of a particle in the direction of the normal to the reference flux line, in terms of which the known drift velocity along the binormal is expressed after averaging.