News: 2 October 2009
First ions to ALICE
During the week end of September 27 and 28, Alice was collecting data related to the lead beam injection test. The lead bunches were accelerated in SPS and transported by the transfer line TI2 to LHC and dumped on TED, about 300 m upstream of Alice.
With a dedicated "beam injection" trigger Alice could register flashes of particles emerging from the dump and illuminating all the detectors. Apart from the opportunity to collect spectacular, high multiplicity events, work was done to understand the trigger time alignment.
The main detectors participating in this exercise were: ACORDE, SDD (Silicon Drift Detector), SSD (Silicon Strip Detector), T0, TOF (Time of Fight), V0 and partially EMCAL (Electromagnetic calorimeter), FMD (Forward Multiplicity Detector) and ZDC (Zero Degree Calorimeter). The combined trigger was delivered by ACORDE, EMCAL, T0 and V0. The TPC (Time Projection Chamber) was not part of this exercise and the magnet was off. These lead bunch splashes look quite similar to the previously observed proton bunch splashes, however they have quite a symbolic value for Alice since it is the dedicated heavy ion LHC experiment.
The pictures are event displays where one can see hits in all the detectors participating in the run.
