SILEM : a new gaseous detector with integrated x-y readout plane

This works reports on gaseous detectors developments made in the frame of the EXO double-beta decay experiment. LEM (Large Electron Multiplication) are electron amplification grids based on GEM. They were developed in Neuchatel and showed remarquable resistance to sparks. The new SILEM grid combines the properties of the standard LEM with a micropatterned x-y readout plane on one of the grid side. It allows thus the amplification of the primary electrons and their position determination in the x-y plane.