We describe a pileup analysis based on data collected at the X-ray Calibration Facility (XRCF) in 1997 February and April during phases F and H of the calibration operations. Our primary goals are to investigate possible trends of pileup with source flux and grade selection, and to compare in detail the measured pileup fraction with current theoretical models, in order to assess the general validity of the latter for predicting pileup for in-flight observations.
A more general discussion of pileup was done in the
ACIS Calibration Report
. Here
we concentrate on an application to the data.