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Season Five Research Files
Episode Twenty-two
4:00am - 5:00am
Backscatter is the reflection of waves, particles, or signals back to the direction they came from.
While a traditional x-ray machine detects hard and soft materials by the variation in transmission through the target, the backscatter x-ray sees the radiation that comes back from the target and delivers a higher resolution image.
The backscatter technology uses high energy x-rays that are more likely to scatter than penetrate materials. Although it is harmless, it can move through other materials, such as clothing. A person is scanned by rastering or moving a single high energy x-ray beam rapidly over their body. The signal strength of detected backscattered x-rays allows a highly realistic image to be reconstructed.
This backscatter technology has been proposed as an alternative to personal searches at airport and other security checkpoints, since it can easily penetrate clothing and reveal concealed weapons and other items. Since it would give screeners a nude picture of the subject, there are privacy challenges. It is being testing by Homeland Security at American airports and in some British Tube stations.
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