On 8 February, the LHCb collaboration succeeded in extracting data from an almost-complete set of detectors. The exercise was an important test run to flag up any problems in the experiment before the next commissioning week in March.
Sixty electronic boards that read out information from the triggered events were used during the tests, collecting data at a frequency of 100 Hz. As not all of the boards have been installed or commissioned yet, this represents only around 20% of the data that the detectors are capable of generating.
There were also indications that cosmic tracks were recorded in the calorimeter system and the outer tracker. Because LHCb is set up with the detectors aligned in vertical planes, it is not easy to record the tracks of cosmic rays. However, there are rare cosmic rays that travel almost horizontally at a rate of a fraction of a hertz through LHCb. The main goal of the commissioning week in March is to collect cosmic events in all detectors together. This will allow an initial alignment in time of all of the components and provide some tracks to be used by the reconstruction and alignment teams.
