IL NUOVO CIMENTO Vol. 37 C, N. 1 Gennaio-Febbraio 2014 DOI 10.1393/ncc/i2014-11687-4
Colloquia: IFAE 2013
Performance studies on MicroMegas detector
M. Trovatelli Universit`a di Roma Tre e INFN, Sezione di Roma Tre - Roma, Italia ricevuto l’1 Ottobre 2013
Summary. — MicroMegas detector is one of the technologies chosen for the up- grade of the forward muon detectors of the ATLAS experiment, in view of LHC luminosity increase. Performance studies on MicroMegas detector, such as time and spatial resolution, based on data collected at the CERN SPS beam line, are here reported and discussed. PACS 29.40.Cs – Gas-filled counters: Ionization chambers, proportional and avalanche counters.
1. – Introduction
After the long shutdown planned for 2018, the Large Hadron Collider at CERN labora- tory will reach the nominal luminosity of 2.5×1034 cm−2 s−1 and the ATLAS experiment will enter in the Phase-1 upgrade [1]. In order to benefit from the high luminosity operation of the collider the Small Wheels (SWs), which are placed in the endcap part of the ATLAS muon spectrometer and cover approximately 50% of the whole acceptance of the muon system, will be replaced. In this region of the detector there is the highest cavern background flux, which will become higher with the LHC luminosity increase expected for 2018, eventually causing detectors performance deterioration. For this reason ATLAS has decided to partially substitute the muons detectors in the New Small Wheels (NSWs) with MicroMegas detectors (MM), which have a higher rate capability than MDTs detectors. In developing MicroMegas detectors for the upgrade several test beams were per- formed at CERN in 2012 by the MAMMA Collaboration (Muon ATLAS MicroMegas Activity), using a 120 GeV/c pion beam coming from the Super Proton Synchrotron (SPS).
2. – Detector technology
MicroMegas is a high gain gaseous detector which consists of a planar drift electrode, a gas gap of few mm thickness acting as ionization and drift region, and a thin metallic