The surface Resistive Plate Counter (sRPC): an RPC based on MPGD technology

The Surface Resistive Plate Counter (sRPC) is a novel RPC based on surface resistivity electrodes, a completely different concept with respect to traditional RPCs that use electrodes characterised by volume resistivity. The electrodes of the sRPC exploit the well-established industrial Diamond-Like-Carbon (DLC) sputtering technology on thin (50 mu m) polyimide foils, already introduced in the manufacturing of the resistive MPGDs such as mu-RWELL and MicroMegas, that allows to realise large area (up to 2x0.5 m(2)) electrodes with a surface resistivity spanning over several orders of magnitude (0.01 divided by 10 G Omega/rectangle). Two detector layout has been developed: the baseline layout with the DLC connected to the HV by a single dot connection outside the active area and the high rate layout with a screen printing a conductive grid onto the DLC film, which exploit the concept of the high density current evacuation scheme first introduced for the mu-RWELL. Besides the use in HEP experiments as timing detector this new technology could be exploited as thermal neutron device for homeland security applications (e.g. Radioactive Portal Monitors for ports and airports), replacing one or both DLC electrodes of the sRPC with plates coated with similar to 3 mu m thick (B4C)-B-10 layer, thus obtaining neutron converters inside the active volume of the detector. Results obtained by irradiating the detectors at the calibrated Am-241-B ENEA-Frascati HOTNES facility will be discussed.