Performance of the CMS RPC upgrade using 2D fast timing readout system

We present a new generation of Resistive Plate Chambers (RPC) that are able to withstand high particle fluxes (up to 2 kHz cm$^{-2}$). These chambers will be instrumented with a precise timing readout electronics and they are proposed to equip two of the four high eta stations of the CMS muon system. Two-gap RPC detectors, with each gap made of two 1.4 mm High Pressure Laminate (HPL) electrodes and separated by a gas gap of the same thickness, are proposed. The new scheme reduces the amount of the avalanche charge produced by the passage of a charged particle through the detector. This improves the RPC rate capability by reducing the needed time to absorb this charge. To keep the RPC efficiency high a sensitive, low-noise and high time resolution Front-End Electronics Board (FEB) is needed to cope with the low charge signal. An ASIC called PETIROC that has all these characteristics is proposed to read out the new chambers. A thin (0.6 mm) Printed Circuit Board (PCB), 165 cm long, equipped with pickup strips of average pitch of 0.75 cm is inserted between the two RPC gaps. The strips are read out from both ends and the arrival time difference of the two signals is used to determine the particle position along the strip ($\eta$ position). The absolute time measurement will also be used to reduce the data ambiguity due to the expected high pileup at the High-Luminosity phase of the Large Hadron Collider (HL-LHC).