A large-area GEM detector using a novel self-stretching technique

A Gas Electron Multiplier(GEM) detector with an effective area of 300 mm×300 mm has been constructed using a novel self-stretching technique, which allows a highly flexible and efficient GEM detector assembly free of glue or spacers. This makes the re-opening and repair of the GEM detectors possible and significantly reduces the scrap rate in the mass production of large-area GEM detectors. With the technique, the assembly time can be limited to a few hours, a factor of ten improvement compared to that using gluing techniques. The details of design and assembly procedure of the 300 mm×300 mm GEM detector are described in this paper. This detector was tested with 8 ke V X-rays for the effective gain, energy resolution and performance uniformity. The results show that the typical energy resolution is 20% at an effective gain of about 104, with fairly good uniformity.