Ion currents and energy spreads for Zr-, Cu- and Au-ion beams in a plasma sputter-type negative ion source
Abstract
Beams of Au-, Zr -and Cu- are produced in the Plasma Sputter Type Negative Ion Source (PSTNIS) by plasma sputtering of the target metal surface. An Electrostatic Energy Analyzer (ESA) was used to sample the negative ion beams which have energies that did not exceed 470eV. Using these data, the corresponding ion currents and energy spreads of the beams were also calculated. The ion current of Cu- was found to have the highest ion current at 1.9µA and Au- the lowest. Energy spread values for Au- and Zr- increased as target voltage was increased while Cu- remained almost constant.