Engineering design of improved power supply current measurement and RF-amplifier layout

This report concerns technical investigations to mitigate beam current fluctuations on the 100 µs time scale for beams slowly extracted from a synchrotron, referred as spill microstructure. During the first 24 months of the IFAST WP5.3, the engineering design for two technical systems were performed. The first device concerns the measurement of the magnet power supplier ripples (refers to remaining AC current I_AC) in the presence of a strong DC current I_DC.  It comprises a combination of current transformers, and a resolution of almost ΔI_AC/I_DC = 1x10^-7 is reached within a bandwidth of 10 Hz to 40 kHz. The second topic contains the control electronics and power amplification chain for the knock-out extraction. A preliminary yet detailed specification of technical parameters was prepared, while the beam-based experiments were performed. The main observation in the experiments was that spill microstructure depends strongly on the signal shape and excitation bandwidth. The technical design of the power chain was modified to the required power level and bandwidth; and the basic layout was elaborated. For the control, a versatile Software Defined Radio technology can be used; its applicability was demonstrated.