Advances in photocathode development for PICOSEC Micromegas precise-timing detectors
Abstract
The PICOSEC Micromegas detector is a precise-timing gaseous detector that combines a Cherenkov radiator, a semi-transparent photocathode and a Micromegas amplification stage, targeting time resolutions of tens of picoseconds for minimum ionising particles (MIPs). Initial single-pad prototypes achieved ps, demonstrating strong potential for High Energy Physics (HEP) applications. The objective of this paper is a~comprehensive characterisation of photocathodes, with a strong focus on robust materials while preserving excellent timing performance. The study includes laboratory measurements of optical and resistive properties together with beam tests using 150 GeV/ muons to evaluate time resolution and photoelectron yield for various photocathodes. The best performance was delivered by a~5\,nm Cesium Iodide (CsI) photocathode, reaching ps with more than 30 extracted photoelectrons, representing the most precise time resolution achieved by PICOSEC Micromegas to date. Metallic and carbon-based photocathodes, including Titanium (Ti), Boron Carbide (BC) and Diamond-Like Carbon (DLC), were also tested, with Ti and BC emerging as the most promising alternatives, achieving ps with about 5 extracted photoelectrons. These results demonstrate that improved robustness can be achieved while maintaining excellent time resolution, supporting the feasibility of using the PICOSEC Micromegas concept in future experiments.
Cite
@article{arxiv.2604.17953,
title = {Advances in photocathode development for PICOSEC Micromegas precise-timing detectors},
author = {M. Lisowska and F. Guerra and A. Gurpinar and D. Zavazieva and R. Aleksan and S. Aune and J. Bortfeldt and A. Breskin and F. M. Brunbauer and M. Brunold and J. Datta and G. Fanourakis and S. Ferry and K. J. Floethner and M. Gallinaro and F. Garcia and I. Giomataris and D. Janssens and E. Jelinkova and A. Kallitsopoulou and I. Karakoulias and M. Kovacic and P. Legou and J. Liu and M. Lupberger and D. J. G. Marques and Y. Meng and H. Muller and R. De Oliveira and E. Oliveri and T. Papaevangelou and M. Pomorski and L. Ropelewski and D. Sampsonidis and T. Schneider and B. Schoenfelder and E. Scorsone and M. van Stenis and Y. Tsipolitis and S. Tzamarias and A. Utrobicic and I. Vai and R. Veenhof and L. Viezzi and P. Vitulo and X. Wang and S. White and Z. Zhang and Y. Zhou},
journal= {arXiv preprint arXiv:2604.17953},
year = {2026}
}