Abstract: An ionization chamber for use in determining the spatial distribution of x-ray photons in tomography systems comprises a plurality of substantially parallel, planar anodes separated by parallel, planar cathodes and enclosed in a gas of high atomic weight at a pressure from approximately 10 atmospheres to approximately 50 atmospheres. The cathode and anode structures comprise metals which are substantially opaque to x-ray radiation and thereby tend to reduce the resolution limiting effects of x-ray fluoresence in the gas.In another embodiment of the invention the anodes comprise parallel conductive bars disposed between two planar cathodes.Guard rings eliminate surface leakage currents between adjacent electrodes.

Abstract: An improved ionization chamber type x-ray detector comprises an array of substantially parallel, flat metal plate electrodes separated and supported by sheets of a glass fiber reinforced silicone dielectric. The silicone-glass fiber dielectric substantially reduces the microphonic and photoconductive currents which characterized prior art detector arrays.