Sunday, March 05, 2006

Radiation detection for fun and profit

Portable radiation detectors used to detect radioactive materials in trucks were sensitive enough to catch a woman on the way home from a medical procedure. The woman had just had a stress test which required the injection of radioactive material and was driving down the highway after the procedure when she was detected by inspectors in a parked vehicle. (from FARK)

I can sympathize with this woman's experience. Way back in graduate school I used an experimental technique called neutron scattering. One takes a nuclear reactor with a tiny opening that allows neutrons through. Slow the neutrons down, collimate them and filter them to one wavelength. The neutrons pass through a sample and the scattering pattern they produce contains information about the microstructure of the sample. It is one of the coolest techniques I know of in science and was a lot of fun to use in my research.

As you might imagine, there are many important radiation safety rules. You must pass through radiation detectors to enter and leave the room where the experiments are performed to make sure that no radioactive material leaves the room for safety reasons. The detectors start by stepping in them or when they detect any radiation, this last property was the source of the fun.

During one of our trips to NIST, where the experiments were performed, one of the group had just undergone a medical test similar to the one of the woman above that involved injecting a radioactive tracer. The sensitivity of the radiation detectors at NIST was so high that this newly radioactive group member could set them off from 40 feet away. His residual radioactivity was so high that he could make you fail the test (proclaimed with loud alarms and flashing lights) while you were in the machine and he was far away. It was great (if a bit geeky) fun.

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1 comment:

Bex said...

Hey Bro,

Mr. Burns (from "The Simpsons") was a great touch to this article, in getting your point across. I have to say, that was one of my favorite episodes...but you left out the "throat scraping" (hee, hee)...I guess that would have been a little off topic.

Love ya, Bex.