Figure 2
(a) Plots of the position and intensity drift observed with and without feedback over a 2 h period. The 10 min top-up cycle is visible in the intensity and position variation. The slow cycles in the positions without feedback operation, particularly in Y, are not currently understood but are actively corrected by the feedback. (b) Position and intensity as energy is adjusted across a wide range. The perturbations at the beam-position monitor during the energy changes are included. The intensity is displayed in amplified volts for scaling. The ion chamber arrangement consists of two split ion chambers or four amplified signals corresponding to a 0–40 V range. |