Power Loss Calculation in Separated and Common Beam Chambers of the LHC

The performance of 25ns beams in the LHC is strongly limited by the electron cloud. To determine the amount of electron cloud in the cold sections of the machine, it is very important to be able to disentangle the beam induced heating due to the beam coupling impedance from that attributable to electron cloud. This paper will focus on the calculation of the first contribution. First, the impedance model used for the calculation of the beam induced power loss is briefly discussed. Then, the methods for the calculation of the beam induced power loss in regions with one or two beams are also described. Finally, the calculated power loss is compared with the measured heat loads for both 25 and 50ns beams in both the LHC arcs and in the inner triplets (ITs).