Pulse power measurements and attenuator characterization of the hard X-ray beamline at the Linac Coherent Light Source

The absolute power of the Linac Coherent Light Source pulses has been measured accurately in the hard X-ray beamline by using simultaneously two detectors: an X-ray Gas Monitor Detector (XGMD) in tandem with a radiometer. From these measurements, we were also able to characterize and calibrate in details our sets of beamline attenuators, in addition to extending an absolute calibration for our beamline intensity monitors. Similarly, we demonstrate that commercial optical power meter has a response in the hard X-ray regime, that can be cross-correlated with the absolute power of the LCLS beam.