  X-ray free electron laser (XFEL) can provide X-ray light with about four
order of magnitude higher flux than synchrotron radiation. Pulse light from
XFEL interacts with the target and the resulting photons are collected by
detectors. The strong intensity of XFEL will make multiple photons hit on one
detector pixel and affect the photon energy measurement. Although increasing
the distance between the target and detector could reduce the photons pile-up,
it causes a waste of photons. So the traditional photon counting spectrum
acquisition method is not advantageous in the XFEL case. To meet the
requirements on both spectrum acquisition and imaging, we propose a new
detection method in this paper.
