Parallax-free gas-filled X-ray detector.

摘要

The invention relates to a gas-filled X-ray detector for analysing matter by studying the diffraction of the X-rays.
<??>To minimise parallax errors without using difficult-to-manufacture spherical auxiliary electrodes, it is proposed to generate a radial field throughout the gas-filled space (40) solely with the aid of entrance electrodes (36) brought to appropriate potentials and with the aid of lateral electrodes (44) also brought individually to appropriate potentials. By modifying the potentials the centre of the spherical equipotentials can be displaced to allow parallax error-free analysis of samples (20) placed at variable distances (D) from the entrance window (32) of the detector.
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