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A Predictive Control Algorithm for Time-Division-Multiplexed Readout of TES Microcalorimeters



Malcolm S. Durkin, Galen C. O'Neil, William B. Doriese, Johnathon D. Gard, Gene C. Hilton, Jozsef Imrek, Nathan J. Ortiz, Carl D. Reintsema, Robert W. Stevens, Daniel S. Swetz, Joel N. Ullom


Time division multiplexing (TDM) uses a digital flux-locked loop (DFLL) to linearize each first-stage SQUID amplifier. Presently, the dynamic range of our TDM systems is limited by the use of a proportional-integral controller to maintain the DFLL. In this paper, we use simulations to assess the improvements possible with a predictive control algorithm that anticipates rapid changes in transition-edge sensor current during the rising edge of an X-ray pulse. We calculate that the predictive control algorithm can improve our TDM architecture's dynamic range by 35%. This significant increase in multiplexing capabilities could be used to read out higher-energy X-rays, reduce readout noise, increase multiplexing factors, or reduce SQUID power output.
Journal of Low Temperature Physics


transition edge sensor, SQUID, microcalorimeter, time division multiplexing, digital flux-locked loop, predictive control algorithm
Created January 28, 2020, Updated June 22, 2020