The Muon ATLAS Micromegas Activity (MAMMA) focuses on the development and testing of large-area muon detectors based on the bulk-Micromegas technology. These detectors are candidates for the upgrade ...of the ATLAS Muon System in view of the luminosity upgrade of Large Hadron Collider at CERN (sLHC). They will combine trigger and precision measurement capability in a single device. A novel protection scheme using resistive strips above the readout electrode has been developed. The response and sparking properties of resistive Micromegas detectors were successfully tested in a mixed (neutron and gamma) high radiation field supplied by the Tandem accelerator, at the N.C.S.R. Demokritos in Athens. Monte-Carlo studies have been employed to study the effect of 5.5 MeV neutrons impinging on Micromegas detectors. The response of the Micromegas detectors on the photons originating from the inevitable neutron inelastic scattering on the surrounding materials of the experimental facility was also studied.
The ATLAS detector at the Large Hadron Collider at CERN is designed to study the products of proton collisions at energies up to 14 TeV. One of its subdetectors is a high-resolution Muon ...Spectrometer, designed to exploit the physics potential of the collisions. It consists of 1206 monitored drift tube chambers, which have to pass very strict quality criteria. For this purpose dedicated setups have been developed and automated at the National Technical University of Athens. In the present report the results of testing about 10,000 drift tubes are presented. These criteria comprise the anode wire mechanical tension, the high voltage dark current, the anode wire displacement, and the gas leak rate of the endplugs and the cylindrical drift tube.
The spatial dependence of the timing performance of the R3809U-50 Micro-Channel-Plate PMT (MCP-PMT) by Hamamatsu was studied in high energy muon beams. Particle position information is provided by a ...GEM tracker telescope, while timing is measured relative to a second MCP-PMT, identical in construction. In the inner part of the circular active area (radius r\(<\)5.5\,mm) the time resolution of the two MCP-PMTs combined is better than 10~ps. The signal amplitude decreases in the outer region due to less light reaching the photocathode, resulting in a worse time resolution. The observed radial dependence is in quantitative agreement with a dedicated simulation. With this characterization, the suitability of MCP-PMTs as \(\text{t}_\text{0}\) reference detectors has been validated.
