Simulation of the Signal Processing for the New Interaction Region BPMs of the High Luminosity LHC

New stripline beam position monitors (BPMs) will be installed at the Interaction Regions of the ATLAS and CMS experiments as part of the High-Luminosity upgrade to the LHC. These BPMs will be located in sections of the beamline where the two counter-propagating proton beams co-exist within a single pipe, such that the signal observed on each output port is a combination of the signals generated by each beam. The use of the BPMs as the input for a possible luminosity feedback system places a demanding requirement on the long-term accuracy of the BPMs. Accurate measurement of the position of each beam requires a method for isolating the individual beam signals. A simulation framework has been developed covering all stages of the measurement process, from generation of the signals expected for beams of a given intensity and orbit through to digitization, and has been used to evaluate several candidate methods for extracting the position of each beam in the presence of the unwanted signal from the other.