Draft proposal for the LHCb muon detector using RPC

We propose to use RPCs to equip a substantial part of the muon detector stations M2‐ M5. RPCs made of phenolic plates of low resistivity (ρ 9 10 9 Ωcm) and operated in avalanche mode offer very good performance and several advantages in region IV of M2 and in regions III and IV of M3‐M5. Using this technique it is possible to cover 90 % of the total area behind the calorimeters at moderate cost.