One of the chores that we have to face as summer interns at the CMS experiment is the half-dreaded, half-loved shifts. During these at time endless periods of time, we get to drive about 30 km away from the LHC main site in Meyrin to the so called point 5, or the location of the LHC ring where the CMS experiment is, in the town of Cessy.
A shift involves monitoring the different subdetectors of the experiment, making sure that the temperatures, humidity, voltages and many other parameters stay within the specified ranges. As shifters, we have limited possibilities as to what exactly we can do to fix any problems that might (and do) arise. In case, we are to let the shift experts know about any issues that arise. Sometimes, the problems are trivial, and one must just make a note of them and let it go. However, as Amram and Tico know very well, sometimes serious issues arise, and one has to have the guts to take drastic decisions, such as turning off the detector itself. (Not that we have access to the buttons that do this, but we’re around when this is done).
Last week, for instance, there was a general power failure at point 5. Some of the cooling cycles did not turn on again after power came on, while some of the wires carrying thousands of volts were quickly heating up. Before they cooked, said voltages had to be turned off.
In general these events are quite rare though. It is of course necessary to always have someone controlling each of the subsystems (Data Acquisition, Tracker, Pixels, the different calorimeters, the cathode strip chambers…), because whenever the experiment is running, someone will always have to on duty to check that the data acquisition process is running as smoothly as possible.However, spending 8 hours in a row sitting in a room with many screens, many of which don’t even change their display at all does get somewhat tedious at times…
Update: there is this cool website : http://cms.web.cern.ch/cms/Media/CMSeye/cam6.html. From there you can get a snapshot of the surface control room. It is updated every 5 minutes and if you’re lucky you might even see some of us there!
