ARgon ImAging DetectioN chambEr

Project Information

ARIADNE

Grant agreement ID: 677927

DOI

10.3030/677927

Project closed

EC signature date 15 February 2016

Start date 1 March 2016

End date 31 August 2021

Funded under

• EXCELLENT SCIENCE - European Research Council (ERC)

Total cost

€ 1 837 911,27

EU contribution

€ 1 837 911,27

Coordinated by

THE UNIVERSITY OF LIVERPOOL
United Kingdom

Periodic Reporting for period 4 - ARIADNE (ARgon ImAging DetectioN chambEr)

Reporting period: 2020-09-01 to 2021-08-31

Summary of the context and overall objectives of the project

The Standard Model (SM) of Particle Physics is a theoretical model that explains how fundamental particles and three of the four fundamental forces (electromagnetic, weak and strong nuclear) relate to each other. The SM fails to explain phenomena such as, Dark Matter, Dark Energy and the Matter – Antimatter asymmetry in the Universe. These all provide evidence that physics exists beyond the SM. Neutrinos are the only detected sub-atomic particle that challenge the SM. Neutrinos are electrically neutral, nearly massless sub-atomic particles that are everywhere in the Universe. However, they are extremely elusive to detect. Liquid Argon Time Projection Chambers (LArTPCs) are key for both Neutrino Physics and Dark Matter searches. ARIADNE is a ton-scale liquid argon detector developing game changing optical based imaging of particle interactions.

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.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

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.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

Existing Time Projection Chamber (TPC) readout technology is based on measuring electric charge, and this method is planned to be used in future large-scale single- and two-phase TPC experiments for neutrino physics. Using ARIADNE’s optical readout method as an alternative to current methods in two-phase TPCs would give several advantages, such as better spatial resolution, reduced cost and complexity of detector design and construction, and lower energy detection thresholds.

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.

ARIADNE detector and team at CERN

Examples of 3D imaged cosmics using TimePix3 Cameras

A photograph of an electromagnetic shower in ARIADNE

The ARIADNE detector being closed

Examples of cosmics imaged with EMCCD cameras