Physics never sleeps
||Physicists from all over the world work the night shift to guide the Large Hadron Collider and its particle detectors from sunset to sunrise. Take a peek into two of the five CERN control rooms that are staffed 24 hours a day. Photo: CERN
ATLAS Control Room, Meyrin, Switzerland
11:30 p.m., Nov. 4
It is half an hour into the night shift at the control room for the Large Hadron Collider's ATLAS detector, and there is nothing to do. The LHC is not running.
"We can't do anything. We just have to wait," says shift supervisor Adrian Vogel.
The LHC lost its beams of particles at 2 p.m. due to a technical problem. The wait could stretch much longer. With such a complex machine, people are constantly fixing parts and making modifications. While they do this, no data can be taken. The nine people on duty in the ATLAS Control Room sit silently.
Around 11:50 p.m., a message appears on one of the monitoring screens projected on the wall:
"Problem with BOOSTER injection
seems to be solved
we will inject soon
Next: Fill for PHYSICS"
The LHC is about to come to life again.
1:30 a.m., Nov. 5
A synthetic whooshing noise fills the room. It ends with a dramatic—but fortunately equally artificial—explosion. Vogel explains there are a few different sounds to indicate the status of the LHC. The whoosh means the beams are stable and the experiments can soon begin taking data. When they lose the beams, they hear a toilet flushing.
In about an hour and a half, the LHC went from empty to colliding particles traveling at 99.999997 percent the speed of light. The process used to take much longer, but, after three years of operation, starting the world's largest particle collider is usually routine. Tonight is the LHC's 3265th running period.
The ATLAS Control Room becomes a bit livelier as people adjust the ATLAS detector to begin accepting and recording particle collisions. While the CERN Control Center focuses on maintaining beams in the Large Hadron Collider and its associated accelerators, the ATLAS Control Room monitors what happens once the particles reach their enormous detector. One of the main jobs is to adjust the trigger, which selects which collisions are recorded. With so many collisions happening at once, only a fraction can be kept for later analysis.
Everything goes smoothly and ATLAS begins taking data.