Expanding the timing frontier: precision timing for particle tracking and identification

The large increase in pileup (overlapping proton-proton interactions) at the HL-LHC is one of the leading experimental challenges for its physics programme. The effects of pileup can be mitigated with a novel and powerful approach: using high-precision timing information to resolve collisions occurring very close in space but well-separated in time, i.e., enabling tracking in 4D rather than in 3D as currently done.

To achieve this, the development of novel detectors achieving first-rate position resolution together with a timing of a few tens of picoseconds is crucial. Low-Gain Avalange Diode sensors (LGADs) have shown a suitable time response but they do not allow for the formation of small nor are yet radiation hard enough to operate in the innermost layers of the ATLAS ITk pixel detector or to be included in the upgrades of the LHCb experiment.

Promising options under development to reach ultra-fast timing are 3D sensors, where the electrodes penetrate the bulk, and monolithic active sensors.

To advance the development of these novel sensors for the upgrades of LHC experiments and prepare for experiments at future colliders, improved instrumentation providing fast timing capability is crucial. Such devices will also bring unprecedented opportunities across all of the STFC's areas and facilities.

This grant will permit the procurement of a 12 GHz signal generator, a fast oscilloscope (<8ps per sample), and a logic analyser. These will enable the proper characterisation of ultra-fast silicon detectors and associated readout at realistic operating conditions, in particular enabling precise measurements of their (ultra-fast) response signals.

The equipment will also enable the characterisation of fast silicon light sensors (SiPMs) towards their use is large-scale arrays for the detection of dark matter.

Detector development is the engine of discovery in particle physics. This proposal aims to procure the necessary equipment to develop new technologies to ensure vitality of our field in the UK, and to future-proof STFC research through active R&D, with outstanding discovery potential for the future.