ФИЗИЧЕСКИЕ ПРОЦЕССЫ В ИОНИЗОВАННОЙ ЛАЗЕРНЫМ ИЗЛУЧЕНИЕМ АТМОСФЕРЕ ПРИ СОЗДАНИИ ЛИНИИ РАДИОСВЯЗИ

Abstract

The results of studies of ionization processes in the atmosphere that occur under the action of laser radiation make it possible to consider the possibility of using directed laser beams for location or formation of a communication channel. To do this, with the help of laser radiation in the atmosphere, a channel with a weakly ionized wall is formed, into which radio emission is introduced. The mini mum electron concentration Ne in the ionized channel, which ensures the reflection of the transmitted electromagnetic wave, depends on its frequency. If the frequency of electromagnetic radiation propagating in the channel is less than the frequency of plasma oscillations in the medium, then the waves are completely reflected from the ionized layer. In the range of long waves (1000-3000 m), the effect of self-radiation of plasma centers can be used to transmit information. By changing the dimensions of the plasma source in space, by modulating the laser radiation, it is possible to vary the frequency and amplitude of the emitted electromagnetic waves in a given range. The main mechanisms of creation of weak ionization channels in the atmosphere by laser radiation are considered. A scheme for the transmission of electromagnetic energy is proposed and its parameters are calculated. A variant of electromagnetic energy transfer by creating a plasma mirror in the atmosphere is considered. The frequency, duration, and energy of laser pulses necessary to create weak ionization channels in the atmosphere and ionosphere are estimated. The calculations and experiments carried out showed that an IR laser sub nanosecond radiation source with a pulse repetition rate of 108 Hz and providing a breakdown or pre-breakdown ionization mode can be used to transfer electromagnetic microwave energy in the atmosphere. It has been established that in the atmosphere it is possible to use both the breakdown mode and the pre-breakdown mode for generating and transmitting long-wave and microwave electromagnetic radiation. It is shown that in the pre-breakdown mode of aerosol ionization, anomalous scattering on plasma particle halos may occur due to the formation of plasmons, which increase the scattering intensity by 2-3 orders of magnitude.