Emittance evolution of a tightly focused electron bunch with high energy spread

The production of a self injected high energy electron beam from laser-plasma interaction is one of the goals at the LI2FE infrastructure at LNF. The formation and acceleration of a beam produced with the experimental setting available in Frascati has been simulated by C. Benedetti et al. by means of the code AlaDyn [1]; the results, shown in Figure 1, foresee that the bunch should have a total charge of about 3.5 nC, a transverse size of few microns and a very broad spectrum, ranging from a few MeV up to about 1 GeV, in agreement with other numerical and experimental results produced world wide. In particular, a neatly separated charge portion at high energy is present (Figure 2), whose main parameters are reported in Table 1, which constitutes the most interesting product of the plasma based accelerator.