Efficient low-energy beam transport for intense, high-brightness H[sup [minus]] beams in high energy accelerators: Perspectives and a solution using ESQ lenses

The characteristics of a 30 mA, 35 kV H[sup [minus]] beam from a volume source have been determined using emittance measurements. A low energy-beam transport (LEBT) system consisting of six electrostatic quadrupole lenses and a short (about 5 cm long) single-stage einzel lens is designed with the aim of transporting the beam over a distance of about 30 cm and focusing a clean, matched beam into a radio-frequency quadrupole accelerator of the Superconducting Super Collider. The system parameters are chosen on the basis of simulation of beam dynamics. The emittance growth in the LEBT section is within a factor of about 1.5 and this satisfies the requirement of the emittance budget. The LEBT system is designed to be mechanically rugged.