Phased Contrast X-Ray Imaging

The Pacific Northwest National Laboratory is developing a range of technologies to broaden the field of explosives detection. Phased contrast X-ray imaging, which uses silicon gratings to detect distortions in the X-ray wave front, may be applicable to mail or luggage scanning for explosives - it can also be used in detecting other contraband, small-parts inspection, or materials characterization.

Transcript

00:00:03 hi my name is Aaron Miller I'm a physicist here at Pacific Northwest National Lab for the past three years we've been working on a project called phase contrast x-ray Imaging and we're hoping to use it for enhanced explosives detection this area research was initiated by a group in Switzerland we're looking to apply it to problems in explosive detection things like mail

00:00:20 scanning or luggage scanning can also be used for detecting Contraband or things like small parts inspection and materials characterization the way this technique works is very similar to a regular x-ray radio graph which is based on absorption of the x-rays so the guts of this is you have the X-ray source which it's on the left in the figure you have an object of Interest here in the

00:00:40 middle and then you have detector on the right this differs from a standard absorb Imaging setup by the addition of these three silicon gradings which allow us to detect distortions in the X-ray wavefront that's a separate piece of information than what we can get from a standard radiograph one scenario might be if you were trying to screen mail for somebody

00:00:59 trying to hide something in a small package you would run your package on a conveyor belt through a detector just like a regular x-ray system but it's a little bit different because with this technique there are some gradings that we add to the normal x-ray measurement when we do our some processing what we get out is actually three distinct images an absorption image which is what

00:01:18 you get out of a conventional radiograph a phase contrast image which is based off those distortions and then a scattering image which is actually very sensitive to texture on the sort of nanometer to Micron scale and so scatter turns out to be a very sensitive indicator of things like a powder or wood or paper where there's a lot of that small scale

00:01:40 texture it's the combination of these three different pieces of information two of which the phase and the scatter we didn't have before with the conventional x-ray system that has us really excited about finding better ways new ways to find explosives for