First Ideas on Measuring Beam Energy and Energy Spread of the 160 MeV Linac4 H- beam with Detached Electrons

This note describes first simulation studies on an alternative method for energy measurements with a 160 MeV Linac4 H- beam. Electrons are detached from H- ions by interactions with rest gas atoms in the beam pipe. The resulting electron current is measured as a function of a variable electric voltage, which can be applied to retard or stop the electrons. The question is addressed which maximum step width of this retarding voltage can be selected to still precisely determine the Linac4 beam energy and energy spread.