title: Simulation of H- ion source extraction systems for the Spallation Neutron Source with Ion Beam Simulator.
abstract: A three-dimensional ion optical code IBSimu, which is being developed at the University of Jyväskylä, features positive and negative ion plasma extraction models and self-consistent space charge calculation. The code has been utilized for modeling the existing extraction system of the H(-) ion source of the Spallation Neutron Source. Simulation results are in good agreement with experimental data. A high-current extraction system with downstream electron dumping at intermediate energy has been designed. According to the simulations it provides lower emittance compared to the baseline system at H(-) currents exceeding 40 mA. A magnetic low energy beam transport section consisting of two solenoids has been designed to transport the beam from the alternative electrostatic extraction systems to the radio frequency quadrupole.
authors.affiliation: Department of Physics, University of Jyväskylä, Jyväskylä, Finland. taneli.kalvas@jyu.fi
authors.forename: T
authors.initials: T
authors.lastname: Kalvas
authors.forename: R F
authors.initials: RF
authors.lastname: Welton
authors.forename: O
authors.initials: O
authors.lastname: Tarvainen
authors.forename: B X
authors.initials: BX
authors.lastname: Han
authors.forename: M P
authors.initials: MP
authors.lastname: Stockli