Construction and characterisation of high time resolution 3D diamond pixel detectors

Track reconstruction at future hadronic colliders such as FCC-hh poses non negligible challenges due to the expected unprecedented levels of radiation affecting the tracking detectors. Detectors featuring excellent spatial and time resolution as well as very high radiation hardness are deemed to be essential for efficient tracking at future experiments. 3D Diamond pixel sensors are considered very promising candidates to fulfil these requirements as they pair the well known excellent timing characteristics and radiation hardness of diamond. We report on the timing characterisation of innovative 3D pixel diamond detectors with electrodes obtained by a laser graphitisation technique optimised for high time resolution. Results of a test beam provide for the first time a time resolution well below 100 ps with an efficiency larger than 99%. Hybridisation of the sensors with a dedicated timing ASIC is also presented for the first time.