Threshold calibration and threshold finding procedure in various LHCb muon MWPC

Threshold calibration and threshold finding procedure in the LHCb muon MWPCs are discussed in this note. Two thresholds in units of charge [fC] are needed in principle: one for the anodes, e.g. 12fC, and one for the cathodes, e.g. 6fC. In reality 120,000 individual thresholds due to variations in offset in CARIOCA chip, different detector capacitances of pads with different size resulting variations in sensitivity from chamber to chamber have to be calculated in register units [r.u.] and move to the threshold registers located in DIALOG chip. The general formula for thresholds in [r.u.] for a given charge unit [fC] is presented. A list of detector capacitance and the averaged sensitivity needed for threshold calculations are given for the inner-most LHCb muon MWPCs in Appendix.