EPS HEP 2015

Performance of a Large 1 m$^2$ Micromegas Detector Using Ar and Ne based Drift Gases

24 Jul 2015, 17:15

15m

HS42

talk Detector R&D and Data Handling Detector R&D and Data Handling

Speaker

Mr Philipp Lösel (LMU Munich)

Description

Micromegas (MICRO MEsh GAseuos Structures) are used in a broad field of applications due to their excellent spatial resolution and single plane track reconstruction capability. They consist of three active planes, a cathode, a micro-mesh and a strip anode with 0.45 mm modularity. The distance of the micro-mesh from the cathode being typically 5 mm is large in contradiction to the tiny distance of 0.128 mm to the anode, thus creating a drift and amplification region with electric fields differing by a factor of more than 50 and thus increasing the electron transparency of the micro-mesh well above its optical transparency. Standard position information is obtained by the charge center on the responding anode-strips, alternatively in a TPC-like mode, the track of the incident particle can be reconstructed measuring the drift times of the primary ionized electrons as a function of the position of the respective anode-strip. We report on the performance of a 1 m$^2$ in size Micromegas with 2048 electronic channels using detector gases based on Ar:CO$_2$ or Ne:CF$_4$ mixtures. Central questions are hereby: homogeneity of pulse-height and efficiency, mesh-transparency, calibration possibility of positions of single readout strips using cosmic muons and a tracking reference and the impact of the different drift times on the angular and spatial resolution as a function of the incident angle.

Presentation materials

eps_ploesel_240715.pdf