Advances in photocathode development for PICOSEC Micromegas precise-timing detectors

Lisowska, M.; Guerra, F.; Gurpinar, A.; Zavazieva, D.; Aleksan, R.; Aune, S.; Bortfeldt, J.; Breskin, A.; Brunbauer, F.M.; Brunoldi, M.; Datta, J.; Fanourakis, G.; Ferry, S.; Floethner, K.J.; Gallinaro, M.; Garcia, F.; Giomataris, I.; Janssens, D.; Jelinkova, E.; Kallitsopoulou, A.; Karakoulias, I.; Kovacic, M.; Legou, P.; Liu, J.; Lupberger, M.; Marques, D.J.G.; Meng, Y.; Muller, H.; De Oliveira, R.; Oliveri, E.; Papaevangelou, T.; Pomorski, M.; Ropelewski, L.; Sampsonidis, D.; Schneider, T.; Schoenfelder, B.; Scorsone, E.; van Stenis, M.; Tsipolitis, Y.; Tzamarias, S.; Utrobicic, A.; Vai, I.; Veenhof, R.; Viezzi, L.; Vitulo, P.; Wang, X.; White, S.; Zhang, Z.; Zhou, Y.

doi:10.1016/j.nima.2026.171890

Advances in photocathode development for PICOSEC Micromegas precise-timing detectors

Lisowska M., Guerra F., Gurpinar A., Zavazieva D., Aleksan R., Aune S., ...Daha Fazla

Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, cilt.1092, 2026 (SCI-Expanded, Scopus)

Yayın Türü: Makale / Tam Makale
Cilt numarası: 1092
Basım Tarihi: 2026
Doi Numarası: 10.1016/j.nima.2026.171890
Dergi Adı: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Artic & Antarctic Regions, Chemical Abstracts Core, Compendex, INSPEC, Public Affairs Index, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO)
Anahtar Kelimeler: Gaseous detectors, Micromegas, Photocathodes, Timing resolution
Orta Doğu Teknik Üniversitesi Adresli: Hayır

Özet

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 time resolutions of σ<25 ps, demonstrating strong potential for High Energy Physics (HEP) applications and beyond. 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, along with beam tests using 150 GeV/c muons to evaluate the time resolution and photoelectron yield for various photocathodes. The best performance was obtained by a 5 nm Cesium Iodide (CsI) photocathode, reaching σ=10.9±0.3 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 (B4C) and Diamond-Like Carbon (DLC), were also tested, with Ti and B4C emerging as the most promising alternatives, achieving σ≈30 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.