Today marked the end of the combined running (using the entire detector as it would be for recording collisions data) of the ATLAS detector for 2008. Unfortunately the running didn’t include any time with collisions this year, but as you can see in the image, we have still been recording tons of data recently. The blue line is the sum of all the events recorded by ATLAS in days since September 13. “Events” are just snapshots taken at one moment by the detector.
The last few weeks were devoted to getting as much high quality cosmic-ray data recorded as possible, while the detector was still “all in one piece”. Over the next few months, there will still be data recorded, but more often with a few pieces at a time, and usually some piece off for maintenance at any moment.
The data that was just recorded will be analyzed for the next few months to calibrate the detector and get ready for collisions in 2009. The total number of events recorded in the last 44 days was 216 million. That works out to about 57 events recorded per second, every second of the day, for 44 days straight. Each event is a megabyte or so, so we are talking hundreds of terabytes of data written out. You can also see, it wasn’t a constant 57 events per second. There was a week where about half the total data was recorded that was much faster during some special running to accumulate data for the inner detector calibration.