Activity of CERN and LNF groups on large area GEM detectors

Abstract We report on the activity of CERN and INFN-LNF groups on the development of large area GEM detectors. The two groups work together within the RD51 Collaboration, to aim at the development of Micro-pattern Gas detectors technologies. The vast request for large area foils by the GEM community has driven a change in the manufacturing procedure by the TS-DEM-PMT laboratory, needed to overcome the previous size limitation of 450 × 450 mm 2 . Now a single-mask technology is used allowing foils to be made as large as 450 × 2000 mm 2 . The limitation in the short size, due to the definite width of the raw material, can be overcome by splicing more foils together. A 10 × 10 cm 2 GEM detector with the new single-mask foil has been tested with X-rays and the results are shown. Possible future applications for large area GEM are the TOTEM experiment upgrade at CERN, and the KLOE-2 experiment at the Dafne Φ -factory in Frascati