We have evaluated for the first time the Detective Quantum Efficiency of 2 imaging detectors which
are used for Crystallography. Crystallography is the science of determining the arrangement of
atoms within a crystal from the manner in which a beam of usually low energy (8-17.5 keV)
monochromatic X-rays is scattered from the electrons within the crystal. There is a growing
consensus in the scientific world that the Detective Quantum Efficiency (DQE) is the most suitable
parameter for describing the imaging performance of an x-ray imaging device. The DQE describes
the ability of the imaging system to preserve the Signal to Noise Ratio (SNR) on the way from the
radiation field emerging from the very fine and practically monochrome x-ray beam through the
various imaging system components up to the 3-dimensional crystal image.
Normally the DQE of x-ray systems is based on the effective energy of the x-ray beam and the x-ray
dose as measured with a dosimeter. Typical dosimeters are not very accurate at low x-ray energies
which are used in Crystallography. We used an x-ray spectrometer to determine the x-ray photon
Values of DQE at low spatial frequency were at about almost 80 % at 8 keV.