Fast absolute pulse energy measurements at SwissFEL

Modern free electron laser (FEL) facilities often lack the ability to accurately measure the absolute flux of the x-ray pulses on a shot-to-shot basis. These measurements could be used by the machine operators for optimization, and by the users of the photon beam to better understand their data. This contribution presents methodology that combines existing, slow measurements methods currently used in gas detectors across the world and fast, uncalibrated signals from multipliers, meant for relative flux pulse-to-pulse measurements, that creates a shot-to-shot absolute flux measurement though the use of sensor-based conditional triggers and algorithms at SwissFEL