The ARIADNE detector was designed and built in the unprecedented timescale of only two years in order to carry out operation at a CERN charged particle beamline which provides particles of known momentum in order to allow detector characterisation. This was the first time a dual phase LAr optical readout TIME Projection Chamber (TPC) was operated at a beam line, imaging beautiful liquid argon interactions with highly sensitive EMCCD cameras.
ARIADNE demonstrated that EMCCDs have great light sensitivity and high spatial resolution for imaging argon interactions, however they are limited to providing a 2D image. In order to reconstruct the event in 3D the signal must be correlated to a fast light system (i.e. PMT). Although this technique is possible for simple straight line tracks, reconstruction is extremely challenging for environments that have a high event rate and pile-ups (especially in a beamline where there is a high rate of "halo" muons). Upon return of ARIADNE from CERN to the Liverpool LAr Facility a fast imaging TimePIX3 camera was tested representing a key breakthrough creating a dream 3D optical TPC capable of taking videos of particle interactions with ns time and mm spatial resolution. This exceeded the plans presented in the grant proposal.
Beyond development of optical readout, the ARIADNE system provides a platform for innovation of wider detector components, and to date this has included a novel custom-made cryogenic pump, custom-made purification cartridge, a 100 kV high voltage feed-through, ultrasonic position sensors for levelling LAr and an internal cryogenic camera system for monitoring.
Furthermore, within the framework of the ARIADNE program a new manufacturing process has been developed that allows Thick Gaseous Electron Multipliers (THGEMs) to be built out of any glass material using abrasive etching (patent pending; GB2019563.2). THGEMs are key detector components that in the case of ARIADNE are used to generate the secondary scintillation light that is detected by the cameras. The new THGEMs developed within the ARIADNE project offer several fundamental advantages over the current FR4 based design, enhancing performance and stability for a wide range of applications.
All results have been widely disseminated in peer-reviewed journals, conferences, workshops and seminars.
