  In this work a combination of an ionization chamber with one-dimensional
spatial resolution and a MicroCAT structure will be presented. The combination
between gas gain operations and integrating front-end electronics yields a
dynamic range as high as eight to nine orders of magnitude. Therefore this
device is well suitable for medical imaging or applications such as small angle
x-ray scattering, where the requirements on the dynamic of the detector are
exceptional high. Basically the described detector is an ionization chamber
adapted to fan beam geometry with an active area of 192 cm and a pitch of the
anode strips of 150 micrometer. In the vertical direction beams as high as 10
mm can be accepted. Every read-out strip is connected to an analogue
integrating electronics channel realized in a custom made VLSI chip. A MicroCAT
structure utilized as a shielding grid enables frame rates as high as 10kHz.
The high dynamic range observed stems from the fact that the MicroCAT enables
active electron amplification in the gas. Thus a single photon resolution can
be obtained for low photon fluxes even with the integrating electronics. The
specialty of this device is that for each photon flux the gas amplification can
be adjusted in such a fashion that the maximum DQE value is achieved.
