All-Electrostatic Split LEBT Test Results

An all-electrostatic LEBT for an RFQ has been assembled and tested with beam. The LEBT includes two quasi-einzel lenses, allowing a wider range of Twiss parameters to be accommodated, and the lenses are split into quadrants, allowing electrical steering of the beam. Moreover, mechanical steering by moving the entire LEBT with a special low friction vacuum joint was also demonstrated. The LEBT was tested with unanalyzed protons from an RF-driven bucket source by measuring the beam directly and by measuring the transmission through a subsequent RFQ as a function of LEBT electrode parameters.. Agreement between calculated LEBT beam characteristics and actual measured values is excellent. This LEBT offers fully unneutralized beam transport with steering and two knob control of exit Twiss parameters, and can be applied to negative hydrogen as well as proton beams.