Position sensitive VUV gaseous photomultiplier based on Thick-multipliers with resistive line readout

In this work, a new position sensitive gas photomultiplier (GPM) based on a cascade configuration is proposed. The GPM is composed by two THGEMs, followed by a 2D-THCOBRA being operated in Ne/CH4(5%), at a pressure of 1 bar in VUV single photon mode. The 2D-THCOBRA is a hybrid microstructure which combines the benefits of a THGEM and a 2D-MHSP, presenting two independent charge multiplication stages. The position capability is performed by using two orthogonal resistive lines crossing each one the readout electrodes. The position is obtained by measuring the charge sharing in both ends of each resistive line, by using only 2 readout channels. This work focuses the study of the detector gain, Ion Back Flow (IBF) and spatial resolution. A charge gain of 10(6) and an Ion Back Flow (IBF) values of about 20% were measured. Position resolutions below 300 mu m (FWHM) were obtained for single VUV photon counting mode operation.