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O.N. Karavashkina and S.B. Karavashkin

However the most important processes for the star formation occur in the exterior region of protostar. Having broken free from the core of protostar, the electron has a considerable energy and moves against the thermogradient towards the exterior region of protostar cloud. At this moment the buoyant force that promoted its emission already does not affect it, so the electron moves evenly decelerating in the returning positive electric field of the protostar core. So at definite distance from the core, the energy of electron is already comparable with the energy of orbital electrons of a hydrogen atoms that are in the protostar envelope. Now this electron can be involved in polarisation interaction with neutral atoms having low kinetic temperature typical for the substance of envelope; with it a negative ion produces. Due to this interaction, the atom gains a negative charge and encounters the attraction to the positively charged protostar core. It slowly sediments to the centre, and as the bond between the electron and hosting atom is weak, when they enter the high-temperature region of convective layer, the bond destroys, the electron becomes free again and, having gained an additional energy, can again travel away to the periphery of protostar, leaving the hydrogen atom in the convective layer. This produces the electron convection presented in Fig. 2.13; it extends to a distance well exceeding the region of thermal convection and, in distinction from thermal convection, executes the one-sided mass transfer and localises in this way the protostar core. In the view of above classification of protostar evolution stages, these processes relate to Hayashi stage, when the structure of future star results from the processes inside the protostar.

Fig. 2.13. The trajectory of thermoelectron motion in the protostar. The electrons are shown in lilac and neutral atoms carried to the core - in green.

So the "electron pump" is created. With growing temperature of protostar core and related growth of thermoelectron flow, it the more intensively transfers the substance from the envelope to the core. This appears the decisive factor counteracting the force of thermal scattering. The factor determining that the star will go on accumulating, despite the counteraction of thermal scattering.