Upgrade of the ITUR extraction system at ESS-Bilbao

The first beam measurements on our modified version of the ISIS Penning source show a beam of relatively low current. As a result of this, the actual extraction system was simulated using IBSimu, and it was found that the configuration is far from the optimal case. We present a simpler post-acceleration extraction system that avoids the use of a long (similar to 100mm) Cs trap. Due to space and budget constraints, the new extraction is composed of only one electrostatic einzel lens. The same configuration, as the ISIS source, is maintained up to the puller electrode; the changes come afterwards, where two circular electrodes with rectangular apertures make up the einzel lens. This configuration lacks the bending magnet found at ISIS because the permanent magnets used in this version of the source provide the Penning field. This difference results in a low angle beam extraction that is compensated by tilting the source to angles near 15 degrees. In addition to the beam dynamics simulations, the mechanical and electrostatic simulations for the extraction system are presented.