Gas Electron Multiplier Foils Research Articles

Performance test of a micro-pattern stereo detector with two gas electron multipliers

We report on the performance of a large micro-pattern detector with two gas electron multiplier foils and a two-layer readout structure at ground potential. The two readout layers each have a 406 μm pitch and cross at an effective angle of 6.7°. This structure allows for two orthogonal coordinates to be determined. Using a muon beam at CERN together with a silicon tracking system, the position resolutions of the two coordinates are measured to be 50 μm and 1 mm respectively (1 standard deviation). The muon detection efficiency for the two-dimensional space points reaches 96%. The detector was found to be well operational over a wide range in the settings of the different electrical fields.

Construction and performance of a micro-pattern stereo detector with two gas electron multipliers

The construction of a micro-pattern gas detector of dimensions 40×10 cm 2 is described. Two gas electron multiplier foils (GEM) provide the internal amplification stages. A two-layer readout structure was used, manufactured using the same technology as the GEM foils. The strips of each layer cross at an effective crossing angle of 6.7° and have a 406 μm pitch. The performance of the detector has been evaluated in a muon beam at CERN using a silicon telescope as reference system. The position resolutions of two orthogonal coordinates are measured to be 50 μm and 1 mm , respectively. The muon detection efficiency for two-dimensional space points reaches 96%.

The MICROMEGEM detector

This article introduces the MICROMEGEM detector, a position-sensitive proportional gas counter produced using advanced Printed Circuit Board (PCB) technology. The detector is equipped with a Gas Electron Multiplier (GEM) foil placed 50 μm above a plane of pick-up strips. The GEM produces a first gas amplification which is extended below the GEM foil by applying a strong electric field between the strips and the lower electrode of the GEM. The array of strips is used for read-out to obtain 1-D positional information. We present results on the gas gain, the energy resolution and the rate capability. The behaviour in an intense beam of 300 MeV/c pions in presence of heavily ionizing particles has also been investigated.