118826161
Progress on large area GEMs
In 2008, a triple GEM detector prototype with an area of ~ 2000 cm2 has been constructed, based on foils of 66 × 66 cm. GEMs of such dimensions had not been made before, and innovations to the existing technology were introduced to build this detector. This paper discusses these innovations and presents further work on large area GEM development. A single-mask technique overcomes the cumbersome practice of alignment of two masks, which limits the achievable lateral size. The holes obtained with this technique are conical, and have a so-called rim, a small insulating clearance around the hole in the substrate. Further refinements of this technique allow greater control over the shape of holes and the size of rims. Also, an improvement in homogeneity over large areas is expected. Simulation studies have been done to examine the effect of hole shape on the behavior of GEMs. Such studies can help understanding how to use new enhancements of the technique to optimize performance. Many potential applications for large area GEMs foresee large production volumes. Production issues have been studied, and single-mask GEMs turn out to be much more suitable for large scale production than standard GEMs.
116847052
The LHCb RICH PMTs Readout Electronics and the Monitoring of the HPDs Quantum Efficiency
122515004
The Electromagnetic calorimeter for the OBELIX experiment
Abstract We describe the electromagnetic calorimeter of the OBELIX detector installed on the LEAR facility at CERN: the criteria followed to design its structure and the tests and preparation work performed on the different components are discussed, to conclude with the description of the main control procedures operating on the assembled detector during the first tests of the apparatus on the LEAR beam.