摘要 |
<p>An apparatus for X-ray scanning of vehicles includes a pulsed X-ray source (2) generating X-rays. A collimator forms (3) a fan -shaped beam from the X-rays. A detector (5) detects the fan- shaped beam after it passes through a vehicle (6). A speed sensor (9) measures a speed of the vehicle passing through the apparatus and providing an electrical output corresponding to the speed. An image formation module converts an output of the detector into an image of the vehicle, based on the measured speed of the vehicle. The width of the fan- shaped beam is substantially similar to the width of the detector. The X-rays comprise primarily photons with energy between 2.5 and 9 MeV. A filter (19) is adjacent to the collimator for filtering out low energy X-ray photons. A vehicle presence sensor (10) can be used, whose output is used to turn the X-ray source on and off. An alignment platform (13,17) can be used for aligning the fan -shaped beam with the detector. A frequency of the pulses is adjusted based on the speed of the vehicle. The X-ray source is turned off if the speed of the vehicle is below a predetermined threshold.</p> |