The PICOSEC Micromegas (MM) detector is a precise timing gaseous detector consisting of
a Cherenkov radiator combined with a photocathode and a MM amplifying structure. A 100-channel
PICOSEC MM prototype with 10 × 10 cm2 active area equipped with a Cesium Iodide (CsI)
photocathode demonstrated a time resolution below σ = 18 ps. The objective of this work
is to improve the PICOSEC MM detector robustness aspects, i.e. integration of resistive MM and
carbon-based photocathodes, while maintaining good time resolution. The PICOSEC MM prototypes
have been tested in laboratory conditions and successfully characterised with 150 GeV/c muon
beams at the CERN SPS H4 beam line. The excellent timing performance below σ = 20 ps for
an individual pad obtained with the 10 × 10 cm2 area resistive PICOSEC MM of
20 MΩ/□ showed no significant time resolution degradation as a result of adding a
resistive layer. A single-pad prototype equipped with a 12 nm thick Boron Carbide (B4C)
photocathode presented a time resolution below σ = 35 ps, opening up new possibilities for
detectors with robust photocathodes. The results made the concept more suitable for the
experiments in need of robust detectors with good time resolution.