rD < 10cm; in the interstellar space rD < 10 cm. In all space processes with characteristic dimensions bigger than rD plasma must be considered as neutral: in any volume bigger than rD the number of negative particles (mostly electrons) and positive particles (mostly ions) is equal.
1.1.2. Conductivity and magnetic viscosity of space plasma
Space plasma is mainly fully ionized hydrogen. In this case, the conductivity a and magnetic viscosity vm are determined only by the plasma temperature:
1.1.3. The time of magnetic fields dissipation; frozen magnetic fields
The time (in sec) of ohm's dissipation of a magnetic field characterized by the dimension L will be tm = L2Vm = 2.5 x 10-13L2T32 . (1.1.4)
This gives: for magnetic inhomogeneities in the interplanetary space (T ~ 105 K, L > 109 cm) tm > 7 x1012sec ~ 2 x 105 years; for processes near solar spots (T ~ 6x 103 K, L ~ 3x109 cm) tm ~ 1012 sec ~ 3x104 years; for processes in interstellar space (T = 103 K, L > 1015 cm) tm > 1020 sec = 3 x 1012 years; in supernova remnants (T > 104 K, L > 1012 cm) tm > 3 x1017 sec = 1010years. These times are several orders bigger than characteristic times of processes in corresponding space conditions, and in some cases are bigger than the age of Universe. It means that magnetic fields in space plasmas can be considered as frozen in plasmas and moving together with moving matter.
1.1.4. Transport path of ions in space plasma and dissipative processes Space plasma can be mainly considered as un-collisions. In actuality the transport path of ions A,- (in cm) in the fully ionized hydrogen plasma is
According to Eq. 1.1.5 we obtain for space plasma a very long transport path for
collisions: for example, in solar wind (T ~ 10 K, N < 10 cm ) A - > 2 x10 cm .
It means that with all dissipative processes caused by plasma, particle collisions can be neglected.
1.1.5. Space plasma as excited magneto-turbulent plasma
Space plasma, as a rule, can be considered as highly excited magneto-turbulent plasma with intensive macroscopic, collective movements. Sources of space plasma excitation are the following: thermal convection leads to the generation of magnetic fields and their floating to the Sun's surface as sunspots (on the Sun); great discharging processes in solar flares; flowing of the inhomogeneous solar wind with frozen in magnetic field around the Earth's magnetic field and formation of the Earth's magnetosphere with radiation belts and very exiting plasma; explosions of Novae and Supernovae stars in our Galaxy; explosions of galactic nucleuses and collisions of galaxies in the Universe, etc..
Large scale movements in space plasma generate in plasma currents and electro-magnetic fields that lead finally to charged particle acceleration.
1.1.6. Main channels of energy transformation in space plasma
According to Syrovatsky (1968) the first main channel of the space plasma kinetic energy transformation is generation and amplification of a magnetic field up to the equilibrium value H determined by the relation
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