Overview of plasma lens experiments and recent results at SPARC_LAB
Beam injection and extraction from a plasma module is still one of the crucial aspects to solve in order to producehigh quality electron beams with a plasma accelerator. Proper matching conditions require to focus the incominghigh brightness beam down to few microns size and to capture a high divergent beam at the exit without loss ofbeam quality. Plasma-based lenses have proven to provide focusing gradients of the order of kT/m with radiallysymmetric focusing thus promising compact and affordable alternative to permanent magnets in the design oftransport lines.