Beam centroid trajectory control for a high current LIA

In order to reduce the amplitude of corkscrew motion to obtain a high current pulsed electron beam with good quality, both simulation and experimental work were done based on the beam transport system of “Dragon-I”, which is a pulsed high current electron LIA. The beam centroid motion was controlled by adjusting the current fed into two pairs of steering coils located inside the accelerator cavities. The two pairs of steering coils are perpendicular to each other. The principle of the adjustments, simulations and experiments are introduced in this paper. Corkscrew amplitude of the output electron beam with 50 ns pulse flattop is reduced from 4 mm to less than 1 mm.