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How Antimatter Could Stop Iran From Cheating On the Nuclear Deal
But what regular radiation detectors miss, antineutrino detectors could catch. Neutrinos--and their antimatter corollary, antineutrinos--are subatomic particles with no positive or negative charge. They pass through virtually all material you can imagine, from lead shielding to the cores of stars. That could allow monitors to "'see' into the core of a running nuclear reactor and to measure the plutonium content in situ," said Patrick Huber, an associate professor of physics at Virginia Tech. Nuclear reactors produce antineutrinos in unimaginable quantities -- up to 100 billion billion per second.Spotting neutrinos, which move through matter without interacting with it, is very hard. You have to track these "ghost particles" indirectly, by detecting their collisions' effects on other charged particles, and you need a lot of sensors. Examples include Japan's Super-Kamiokande neutrino detector, which is lined with more than 13,000 sensors for observing subatomic neutrino interactions, and the lake-sized Antares detector in the Mediterranean. But antineutrinos have a different energy profile and much larger energy flux so they are easier to detect. When an antineutrino meets a proton, the collision produces a neutron and a positron. (Positrons are the antimatter equivalent of electrons.) As positrons move through matter, they lose energy and eventually collide with electrons. When that happens inside of a so-called scintillator material like mineral oil or plastic, these processes combine to produce measurable light. Similar flashes occur when the neutron meets with a gadolinium or lithium atom. Both of these flashes serve as a smoking gun for antineutrinos -- and possible illicit nuclear activity. Antineutrino detection has never been a part of any weapons monitoring regime. Huber, working with researchers at Los Alamos National Laboratory hopes to change that. They plan to deploy a prototype of a novel detector by the end of the year at a commercial reactor. With enough funding, Huber says that a fully calibrated detector could be ready to go Iran in two years (but one with a full safeguards system likely would not be available in fewer than five.) Posted by: Blossom Unains5562 2015-07-22 |
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