Simulation of Machine Induced Background in the LHCb Experiment: Methodology and Implementation

Numerical analyses of machine induced background at the LHC are needed to evaluate the complete running environment of an experiment. In order to have a comprehensive view of the machine background in an experiment all of its sources, ranging from collimators´ cleaning inefficiency to distant and local beam-gas interactions need to be estimated; particles showering from the losses are then to be transported all the way to the experimental setup and the response of the detector evaluated. In this paper we describe a novel methodology implemented for the LHCb experiment to achieve this. Each step in the chain is simulated with software specific to the task and provides input to the subsequent step through a well-defined and clear interface. Further, we will discuss in detail the various steps in the chain together with the advantages such a modular method allows in evaluating operational conditions where scaling of the initial sources can be applied. We will also give some examples of the results obtained.