Design studies of an electrostatic quadrupole channel for transport of a high-brightness H/sup -/ beam and comparison with gas focusing

Summary Form only given, as follows. The authors developed a conceptual design for an electrostatic quadrupole channel for transport of a 120-keV, 120-mA, H/sup -/ beam into a 425-MHz radio frequency quadrupole accelerator with low emittance growth and high transmission efficiency. This design satisfies several constraints imposed by voltage breakdown and beam optics considerations. The system will consist entirely of electrostatic lenses, which prevent plasma buildup and eliminate possible emittance growth from plasma fluctuations. A worst-case nonlinear analysis for the electrostatic quadrupole channel has been carried out, and preliminary results have been obtained using a particular simulation code to study beam loss and emittance. As an alternative to the electrostatic quadrupole concept, gas focusing is being investigated for transporting low-energy H/sup -/ beams.>