Numerical study of a collimated high charge electron beam generation on laser systems with terawatt peak power

We had numerically studied electron acceleration in the interaction of a terawatt laser pulse with a long-scale target with density approximately $10 \%$ of critical value. Based on PIC simulations, the mechanism of electron acceleration was found to be a combination of direct laser acceleration and laser wakefield acceleration. With the increase in pulse energy, a collimated electron beam with 1 nC charge can be obtained.