Construction and test of full-size Micromegas modules for the ATLAS New Small Wheel Upgrade

In 2015 the first full size resistive-strip Micromegas modules for the ATLAS New Small Wheel upgrade will be realized. The goal is to provide precision muon tracking with spatial resolution below 100 $\mu$m on trapezoidal four-layer detector modules with areas between 2 and 3 m$^2$. This poses stringent limits on the overall accuracy of the modules with respect to strip positioning and planarity. Each module is built as a quadruplet of four resistive strip Micromegas layers, constructed from stiff sandwich panels. An assembly procedure has been developed to build the panels and modules with the required mechanical precision of 30 $\mu$m along the precision coordinate and 80 $\mu$m perpendicular to the chamber. The construction and quality assurance procedures ensure good module quality verified by checks done during the construction and the chamber assembly.