The Frankfurt Funneling Experiment
Funneling is a technique to multiply beam currents of rf-accelerators in several stages at low energies to prevent problems with space charge. The Frankfurt Funneling Experiment is a prototype of such a stage. Two beams are accelerated in a Two-Beam RFQ and combined to one beam axis with a funneling deflector. The last part of the RFQ electrodes of our Two-Beam RFQ has been replaced to achieve a 3d focus of both beams at the beam crossing point behind the RFQ in the center of the deflector. A new designed multi cell funneling deflector and first results of the new experimental set-up will be presented.
Multicusp ion sources (invited)
During the last decade, different types of multicusp ion sources, such as high current, high concentration H+, H+2, or N+ ion sources, negative ion sources, radio‐frequency‐driven sources, and high charge state ion sources have been developed at the Lawrence Berkeley Laboratory. This article reviews the history of the research and development of these ion sources and their applications.
Directly heated lanthanum hexaboride filaments
Some physical properties of lanthanum hexaboride filaments, when operated as cathodes in a gas discharge, are presented. These directly heated hairpin‐shaped filaments have been tested in different types of ion sources and are shown to be capable of long‐pulse or cw discharge operations. The design of a shaped lanthanum hexaboride filament for the purpose of further extension of lifetime is also described.