Periodic Reporting for period 4 - ARIADNE (ARgon ImAging DetectioN chambEr)
Reporting period: 2020-09-01 to 2021-08-31
The ARIADNE project has successfully developed and fully characterised a dream 3D optical imaging LArTPC demonstrating the power of this approach for the readout of future colossal LAr Neutrino experiments. The ultra-fast TimePIX3 based camera system employed within ARIADNE was able to image LAr interactions with mm spatial and nsec time resolution. As a result this technology is now considered as an option for the fourth 10 kton "module of opportunity" within the DUNE programme offering high-resolution 3D imaging and a lower energy threshold thus enhancing the potential for new Particle Physics discoveries. The detectors of the DUNE programme will be the largest ever LAr Neutrino experiments to be made.
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.
The 3D optical imaging and the new glass THGEMs developed within the ARIADNE project have demonstrated and offer a beyond the state-of-the-art LAr TPC which can hold the key to the realisation of the challenging future colossal LAr Neutrino experiments.