The combination of a Cherenkov radiator with a semi-transparent photocathode and a Micromegas based amplification stage allows PICOSEC Micromegas detectors to achieve a time resolution of better than 15ps. While tileable prototypes with 10x10 channels feature 1x1 cm^2 readout pads, finer readout granularity can be used to improve the spatial resolution. We report on the study of high readout granularity PICOSEC Micromegas prototypes which achieve around 0.5mm spatial resolution with 3.5mm large pads. No significant improvement was found when readout pad size was further reduced to 2.2mm. The timing resolution of the leading pad was found to be slightly degraded but remained better than 20ps for a medium granularity prototype. The achieved spatial resolution can enable PICOSEC Micromegas to be used as precise timing and moderate resolution tracking detector simultaneously.
@article{arxiv.2603.18733,
title = {Spatial resolution improvement of PICOSEC Micromegas precise timing detectors},
author = {F. M. Brunbauer and R. Aleksan and Y. Angelis and S. Aune and J. Bortfeldt and M. Brunoldi and J. Datta and D. Desforge and G. Fanourakis and D. Fiorina and K. J. Floethner and M. Gallinaro and F. Garcia and I. Giomataris and K. Gnanvo and Q. Huang and F. J. Iguaz and D. Janssens and A. Kallitsopoulou and I. Karakoulias and M. Kovacic and P. Legou and M. Lisowska and J. Liu and M. Lupberger and I. Maniatis and M. Micetic and H. Muller and E. Oliveri and T. Papaevangelou and M. Pomorski and L. Ropelewski and K. Salamon and D. Sampsonidis and L. Scharenberg and T. Schneider and E. Scorsone and L. Sohl and N. Shankman and M. van Stenis and Y. Tsipolitis and S. E. Tzamarias and A. Utrobicic and I. Vai and R. Veenhof and P. Vitulo and X. Wang and S. White and Z. Zhang and Y. Zhou},
journal= {arXiv preprint arXiv:2603.18733},
year = {2026}
}