Electrons acceleration in plasma channel in the relativistic laser-plasma of solid targets

In this work, we will show that electrons can be accelerated in the plasma channel, which is formed by a laser pulse reflected from a dense plasma. Preplasma, on the one hand, mast have a sufficient length in the low (<0.1nc) density region to create a channel inside it, and on the other hand, does not lead to strong absorption and destruction of the laser pulse and provides injection of the maximum number of electrons into the channel. It is shown that in order to fulfill the latter conditions, the optimum slope of the plasma gradient near the critical density should be similar to 0.5 lambda. In this case, the injection of electrons, which received an initial acceleration after the breaking of plasma waves excited by parametric instabilities, effectively occurs in the plasma channel.