by Virginia Greco and Kristjan Gulbrandsen. Published: 20 August 2018

LHC is delivering proton collisions at 13 TeV energy in the centre of mass and the ALICE experiment is taking standard triggered data (no special configurations). In the last month, though, the amount of data recorded decreased due to various causes. After a few days of machine development, in which the ALICE detector was kept in a safe mode, a period of reduced performance followed. There was some downtime in which collisions were not delivered due to various issues with the LHC (a major electrical perturbation, Proton Synchrotron Booster extraction problems, power converter issues, and radiofrequency cavity irregularities).

ALICE itself also had a few issues that caused the experiment to pause data-taking for some hours. Due to this, and since some specific types of triggered data with lower dead-time were particularly lacking statistics, the instantaneous luminosity in the ALICE detector has been increased from 2.6 to 3.47 Hz/μb, thus, giving a higher event recording rate.

In the meantime, the experts have analyzed the data of the Run 2 and Run 3 equivalent-flux test runs that were performed in June and have decided which data taking configuration to use during the Pb-Pb run at the end of the year. Both tests will be repeated soon, with the Run 2 one scheduled for the last week of August. The Run 3 equivalent-flux test run will be performed in September, just before the planned short period of machine development.