Trillions of supercharged subatomic particles known collectively as “cosmic rays” originate from deep space—probably from supernovae explosions and possibly outside the Milky Way galaxy. Some travel at nearly the speed of light and can easily pass through almost everything you see: your hand, the building behind you, the Earth’s crust—and even the massive detectors of giant physics experiments like those at the Lab’s Relativistic Heavy Ion Collider (RHIC).
That turns out to be a boon for RHIC physicists, who study subatomic smashups of gold ions inside RHIC’s detectors to get clues about what the early universe was like. They’ve come up with ways to use the far-flung supernovae remnants to calibrate the detectors to be sure the data from their experimental particle collisions is recorded as precisely and accurately as possible.
Because cosmic rays are readily available, easy to identify, abundant, and free, they're the perfect micro-tools for calibrating and aligning RHIC’s cutting-edge detection instruments. The collider isn't active all year round, and often a period of dormancy leaves these sensitive detecting tools out of sync—like the keys of a piano that haven’t been played for several months. A piano tuner uses an external source that provides a note in perfect pitch to calibrate the keys. The detectors at RHIC require a similar alignment process when they're first turned on. The physicists use the predictable, consistent radiation patterns of cosmic rays coming in from space as the “perfect pitch” for “tuning” the detectors.
2013-4244 INT/EXT | Media & Communications Office
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