Conditioning of MWPCs for the LHCb muon system

We report on the conditioning of the multi-wire proportional chambers (MWPC) for the LHCb muon system. The MWPCs destined for the inner regions of the muon stations have demanding requirements in terms of rate capability (>100 kHz/cm/sup 2/) and ageing properties. Conditioning of the chambers is therefore of utmost importance. After construction, all chambers undergo a conditioning procedure in two steps, resulting in successful cleaning of anode and cathode surfaces. Conditioned chambers show excellent behaviour under working conditions.