Reducing the magnet switching time for AMS at PRIME lab

At the Purdue Rare Isotope Measurement Laboratory, we are cycling magnets to obtain isotope ratios. Minimizing cycle time increases the precision of those measurements. The magnet change time is a significant fraction of the total cycle time since the magnets must be steady to within a few hundred ppm before measurements can begin. PRIME Lab's goal was to obtain isotope ratios to a precision of 1% or better given sufficient counting statistics. A conventional PID controller was implemented, This reduced the magnet switching time for the injector magnet by approximately 50% and the analyzer magnet by approximately 10%. A dual controller was then implemented. The dual controller consists of an optimization algorithm, called the settling-time optimizer, and a fuzzy logic controller The settling-time optimizer reduces the settling-time with every cycle based on the history of previous cycles and the fuzzy logic controller compensates for any disturbances in the system. This controller gave a much better performance by reducing the switching times for both magnets by approximately 75%.