Quasi-Monochromatic X-Ray Filter with Thin Film Multilayer for a Large Area Radiation Field


We fabricated an X-ray beam filter housing which can acquire large-area 2-dimensional images with a designated narrow band X-ray energy which was generated from the wide energy spectrum of the X-ray beam. The filter housing consists of an array of reflectors and each reflector filters the input X-ray energy from an ordinary X-ray tube and passes an X-ray beam of quasi-monochromatic energy. With a precise alignment of the whole reflectors in the filter housing device it is possible to make the total quasi-monochromatic X-ray beams cover a large area for imaging. The substrate of the reflector itself absorbs some of X-ray photons, which generates shadow of the layers on the image. In order to solve this problem the system was made to rotate around the focal spot of the X-ray tube during the X-ray image acquisition, which resembles the motion of a searchlight, hence there is no blind spot to the X-ray beam. At a preliminary stage we obtained images for a short exposure time of less than 1 second. Representative spectra and full field CDMAM phantom image of 197 mm × 238 mm acquired from the filter housing rotation method are presented. And the advantage of the monochromatic X-ray against the conventional polychromatic X-ray in terms of contrast is investigated. © 2009 SPIE.

Meeting Name

Medical Imaging 2009: Physics of Medical Imaging


Nuclear Engineering and Radiation Science

Document Type

Article - Conference proceedings

Document Version


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© 2009 SPIE, All rights reserved.

Publication Date

01 Jan 2009