Procedure for determination and setting of thresholds implemented in the LHCb Muon system

The LHCb Muon system consists of 1368 Multi Wire Proportional Chambers of different size and readout for a total of ~120k electronics channels. The choice of the correct threshold to be applied to each channel can be made on the basis of the detector simulation or, as we suggest in this note, by measuring the noise parameters for each channel and consequently setting the desired values. When dealing with individual channels of the Muon system, the variations of the specific properties of each CARIOCA channel should be properly taken into account in order to fine tune the thresholds. The discriminator stage of the CARIOCA is characterized by a voltage bias that needs to be properly measured and taken into account in the threshold calculations. The procedure used for such calculations for the physical channels of the Muon system is discussed in detail in this note.