Tens of picoseconds for minimum ionizing particle (MIP) is what the future physics at the High Luminosity LHC is requiring in terms of pile-up and background subtraction. In some cases, high precision timing has to coexist with high rates and high dose conditions. Assuming this context as one of the highest motivating force, numerous applications outside high-energy physics will profit from this precision.
Our detection concept to reach this precision consists in a thin drift Micromegas coupled to a Cerenkov-radiator front window and a semi-transparent UV photocathode. A 1cm2 prototype has already been built to prove the principle. Single-photoelectron response better than 90 ps has been measured with a femtosecond UV laser at CEA/IRAMIS. A time resolution of 24 ps, with a mean yield of 10 photoelectrons, has been measured at the CERN SPS extraction lines with MIPs. Results and potential improvements will be presented.
These excellent results justify the need of addressing now numerous topics in view of the use of the Picosec detector in experiments: lifetime (of the photocathodes in particular), robustness (spark protection), scaling to a multichannel readout, large area coverage, front-end electronics, high rate and so on. In particular, R&D on solid converter (photocathodes, secondary emitter) will represent clearly one of the most important subjects of our next R&D lines and it will necessarily involve various expertise from different fields. These topics will be discussed going through the status of the project and the future research plans.
Irfu/Dedip