New developments in gaseous tracking and imaging detectors

This year we celebrate the 100th birthday of gaseous detectors: Hans Geiger operated the first gas-filled counter in Manchester in 1908. The thin wires, essential for obtaining gas amplification, have been replaced by Micro Pattern Gas Detectors (MPGDs): Micromegas (1995) and GEM (1996). In the GridPix detector, each of the grid holes of a MPGD is equipped with its own electronic readout channel in the form of an active pixel in suitable pixel CMOS chips. By means of chip technology, the grid has been integrated with the chip, forming a monolithic readout device for gas volumes. By applying a protection layer, the chips can be made spark proof. The issue of chamber ageing is addressed. The use of gas as detection material for trackers is compared to Si, and some new developments are set out.