Transport of ultra-short electron bunches in a free-electron laser driven by a laser-plasma wakefield accelerator

Focussing ultra-short electron bunches from a laser-plasma wakefield accelerator into an undulator requires particular attention to be paid to the emittance, electron bunch duration and energy spread. Here we present the design and implementation of a focussing system for the ALPHA-X beam transport line, which consists of a triplet of permanent magnet quadrupoles and a triplet of electromagnetic quadrupoles