A Study of 'Zigzag' Strip Readout for Micromegas Detectors

Micromegas detectors are now commonly used as tracking detectors for nuclear and particle physics experiments. The aim of this work was to optimize the segmentation of a Micromegas readout plane by performing a systematic study of overlapping patterns known as zigzags. By improving the charge sharing between neighboring strips, the zigzag pattern allows one to maintain high spatial resolution even with relatively large values of strip-to-strip distance (pitch). This can decrease the number of channels and therefore substantially lower the cost and complexity of large detector systems such as those proposed for the future Electron Ion Collider (EIC). Using a laser ablation process we were able to successfully build four 10cm x 10cm Micromegas detectors with one hundred different zigzag patterns on a single readout plane. The detectors were tested in the test beam at Fermilab in March 2018 where the spatial resolution of each pattern was measured using the 120 GeV proton beam. Preliminary results show that spatial resolutions of ~90μm for a 0.8mm pitch can be achieved with a negligibly small fraction of single-pad clusters and would provide a substantial improvement for future tracking detectors.