|CDF (red) and DZero (yellow) recorded the East Coast earthquake. Image courtesy of Todd Johnson, AD|
|CDF (red) and DZero (yellow) recorded the Colorado earthquake. Image courtesy of Todd Johnson, AD|
On Tuesday, Aug. 23, the Tevatron accelerator knew something none of the people operating it knew. It felt what employees didn’t, and it reported the news faster than the media could upload it to the Internet.
A 5.9-magnitude earthquake had struck the East Coast, and the super-sensitive Tevatron felt it as it happened about 600 miles away. It had also registered a similar quake in Colorado the night before.
The quakes were recorded by sensors on large underground focusing magnets that compress particle beams from the four-mile Tevatron ring into precision collisions at the CDF and DZero detectors. The sensors keep these areas most sensitive to misalignment under constant surveillance. Quakes can jiggle small numbers of particles – less than one percent of the beam – out of alignment and force the shutdown of parts of the three-story detectors to avoid damage. Tevatron operators compare the sensor recordings with updates from the U.S. Geological Survey to rule out natural causes before having to spend time diagnosing machine trouble that caused beam movement.
Typically, two quakes occurring in this short a timeframe would cause headaches for those who run the Tevatron, but fortunately the machine didn’t have beam in the tunnels at the time.
The Tevatron has recorded more than 20 earthquakes from all over the globe, as well as the deadly tsunamis in Sumatra in 2005 and in Japan in March.