Magnet Circuits

The LHC has 1572 superconducting circuits. Most of the time and resources during the Hardware Commissioning were consumed by tests of each circuit of the collider, the so-called powering tests. The tests consisted in carrying out several powering cycles at different current levels for each superconducting circuit. The number of tests needed for each sector was around 1500, thus more than 12000 for the whole machine. The aim for the 2009 campaign is to minimise the total time needed for re-commissioning these circuits before beam operation at 5 TeV. This will be done by reducing the number of steps needed for those circuits which have been already commissioned in a similar way as it was done for the second commissioning campaign in sector 4-5 and by optimising the test planning and execution applying the huge experience gathered in the last two years of powering tests. The special powering plan designed for sector 3-4 and the commissioning of the new systems such as the QPS upgrade are also presented.