Publications
ARIADNE+: Large scale demonstration of fast optical readout for dual-phase LArTPCs at the CERN Neutrino Platform
2023 A.Lowe, P.Amedo, D.González-Díaz, A.Deisting, K.Majumdar, K.Mavrokoridis, M.Nessi, B.Philippou, F.Pietropaolo, S.Ravinthiran, F.Resnati, A.Roberts, A.Saá Hernández, C.Touramanis, J.Vann
Optical readout of large scale dual-phase liquid Argon TPCs is an attractive alternative to charge readout and has been successfully demonstrated on a 2 × 2 m active region within the CERN protoDUNE cold box. ARIADNE+ uses four Timepix3 cameras imaging the S2 light produced by 16 novel, patent pending, glass THGEMs. ARIADNE+ takes advantage of the raw Timepix3 data coming natively 3D and zero suppressed with a 1.6 ns timing resolution. Three of the four THGEM quadrants implement readouts in the visible light range through wavelength shifting, with the fourth featuring a VUV light intensifier, thus removing the need for wavelength shifting altogether. Cosmic ray reconstruction and energy calibration were performed. Presented is a summary of the detector setup and experimental run, preliminary analysis of the run data and future outlook for the ARIADNE program.
View Paper (https://www.mdpi.com/2673-9984/8/1/46)A Novel Manufacturing Process for Glass THGEMs and First Characterisation in an Optical Gaseous Argon TPC
2021 A. Lowe, K. Majumdar, K. Mavrokoridis, B. Philippou, A. Roberts, C. Touramanis
This paper details a novel, patent pending, abrasive machining manufacturing process for the formation of sub-millimetre holes in THGEMs, with the intended application in gaseous and dual-phase TPCs. Abrasive machining favours a non-ductile substrate such as glasses or ceramics. This innovative manufacturing process allows for unprecedented versatility in THGEM substrates, electrodes, and hole geometry and pattern. Consequently, THGEMs produced via abrasive machining can be tailored for specific properties: for example, high stiffness, low total thickness variation, radiopurity, moisture absorption/outgassing and/or carbonisation resistance. This paper specifically focuses on three glass substrate THGEMs (G-THGEMs) made from Schott Borofloat 33 and fused silica. Circular and hexagonal hole shapes are also investigated. The G-THGEM electrodes are made from indium tin oxide (ITO), with a resistivity of 150 Ω/Sq. All G-THGEMs were characterised in an optical (EMCCD) readout GArTPC and compared to a traditionally manufactured FR4 THGEM, with their charging and secondary scintillation (S2) light production behaviour analysed.
View Paper (https://www.mdpi.com/2076-3417/11/20/9450)Optical Readout of the ARIADNE LArTPC Using a Timepix3-Based Camera
2020 A. Lowe, K. Majumdar, K. Mavrokoridis, B. Philippou, A. Roberts, C. Touramanis and J. Vann
The ARIADNE Experiment, utilising a 1-ton dual-phase Liquid Argon Time Projection Chamber (LArTPC), aims to develop and mature optical readout technology for large scale LAr detectors. This paper describes the characterisation, using cosmic muons, of a Timepix3-based camera mounted on the ARIADNE detector. The raw data from the camera are natively 3D and zero suppressed, allowing for straightforward event reconstruction, and a gallery of reconstructed LAr interaction events is presented. Taking advantage of the 1.6 ns time resolution of the readout, the drift velocity of the ionised electrons in LAr was determined to be 1.608 ± 0.005 mm/micro-second at 0.54 kV/cm. Energy calibration and resolution were determined using through-going muons. The energy resolution was found to be approximately 11% for the presented dataset. A preliminary study of the energy deposition as a function of distance has also been performed for two stopping muon events, and comparison to GEANT4 simulation shows good agreement. The results presented demonstrate the capabilities of this technology, and its application is discussed in the context of the future kiloton-scale dual-phase LAr detectors that will be used in the DUNE programme.
View Paper (https://www.mdpi.com/903954)Letter of Intent: Large-scale demonstration of the ARIADNE LArTPC optical readout system at the CERN Neutrino Platform
2020 Amedo, P (IGFAE) ; Gonzalez-Dıaz, D (IGFAE) ; Lowe, A (University of Liverpool) ; Majumdar, K (University of Liverpool) ; Mavrokoridis, K (University of Liverpool) ; Nessi, M (CERN) ; Philippou, B (University of Liverpool) ; Pietropaolo, F (CERN) ; Resnati, F (CERN) ; Roberts, A (University of Liverpool) ; Saa, A (IGFAE) ; Touramanis, C (University of Liverpool) ; Vann, J (University of Liverpool)
Optical readout of dual phase liquid argon TPCs has been successfully demonstrated by the ARIADNE 1-ton experiment to be a very viable and attractive alternative to charge readout. TPX3 cameras have been shown to be capable of providing a full 3D event reconstruction. In this letter of intent we describe optimisation and testing of the TPX3 camera based technology at a large scale for the potential use in a DUNE kton-scale module. To this end we propose instrumenting the existing 5mx5m CERN cryogenic vessel at the Neutrino Platform with TPX3 cameras. Four TPX3 cameras with a total field of view of 2mx2m will collect the secondary scintillation light produced in the THGEM holes. Cosmic ray data will be collected and a stopping muon analysis will be performed.
View Paper (https://cds.cern.ch/record/2739360?ln=en#)ARIADNE—A novel optical LArTPC: technical design report and initial characterisation using a secondary beam from the CERN PS and cosmic muons
2020 D. Hollywood, K. Majumdar, K. Mavrokoridis, K.J. McCormick, B. Philippou, S. Powell, A. Roberts, N.A. Smith, G. Stavrakis, C. Touramanis and J. Vann
ARIADNE is a 1-ton (330 kg fiducial mass) dual-phase liquid argon (LAr) time projection chamber (TPC) featuring a novel optical readout. Four electron-multiplying charge-coupled device (EMCCD) cameras are mounted externally, and these capture the secondary scintillation light produced in the holes of a thick electron gas multiplier (THGEM) . Track reconstruction using this novel readout approach is demonstrated. Optical readout has the potential to be a cost effective alternative to charge readout in future LArTPCs. In this paper, the technical design of the detector is detailed. Results of mixed particle detection using a secondary beam from the CERN PS (representing the first ever optical images of argon interactions in a dual-phase LArTPC at a beamline) and cosmic muon detection at the University of Liverpool are also presented.
View Paper (https://iopscience.iop.org/article/10.1088/1748-0221/15/03/P03003)Review of Liquid Argon Detector Technologies in the Neutrino Sector
2021 K. Majumdar, K. Mavrokoridis
Liquid Argon (LAr) is one of the most widely used scintillators in particle detection, due to its low cost, high availability and excellent scintillation properties. A large number of experiments in the neutrino sector are based around using LAr in one or more Time Projection Chambers (TPCs), leading to high resolution three-dimensional particle reconstruction. In this paper, we review and summarise a number of these Liquid Argon Time Projection Chamber (LArTPC) experiments, and briefly describe the specific technologies that they currently employ. This includes single phase LAr experiments (ICARUS T600, MicroBooNE, SBND, LArIAT, DUNE-SP, ProtoDUNE-SP, ArgonCube and Vertical Drift) and dual phase LAr experiments (DUNE-DP, WA105, ProtoDUNE-DP and ARIADNE). We also discuss some new avenues of research in the field of LArTPC readout, which show potential for wide-scale use in the near future.
View Paper (https://www.mdpi.com/2076-3417/11/6/2455)First Demonstration of the Use of LG-SiPMs for Optical Readout of a TPC
2020 A. Gola, K. Majumdar, G. Casse, K. Mavrokoridis, S. Merzi, L. Parsons Franca
This paper describes a new method for optical readout of Time Projection Chambers (TPCs), based on the Linearly Graded Silicon Photomultiplier (LG-SiPM). This is a single photon-sensitive detector with excellent timing and 2D position resolution developed at Fondazione Bruno Kessler, Trento (FBK). The LG-SiPM produces time-varying voltage signals that are used to reconstruct the 3D position and energy of ionisation tracks generated inside the TPC. The TPC used in this work contained room-temperature CF4 gas at a pressure of 100 mbar, with two THGEMs to produce secondary scintillation light. A collimated 241Am source (Qα = 5.486 MeV) was used to produce the ionisation tracks. The successful reconstruction of these tracks is demonstrated, and the consistency of the methodology characterised through varying the geometry of the tracks within the TPC. Energy reconstruction and deposition studies are also described, demonstrating the feasibility of the LG-SiPM as a potential option for optical TPC readout.
View Paper (https://iopscience.iop.org/article/10.1088/1748-0221/15/12/P12017)First demonstration of 3D optical readout of a TPC using a single photon sensitive Timepix3 based camera
2019 A. Roberts, P. Svihra, A. Al-Refaie, H. Graafsma, J. Küpper, K. Majumdar, K. Mavrokoridis, A. Nomerotski, D. Pennicard, B. Philippou, S. Trippel, J. Vann
The ARIADNE project is developing innovative optical readout technologies for two-phase liquid Argon time projection chambers (LArTPCs). Optical readout presents an exciting alternative to the current paradigm of charge readout. Optical readout is simple, scalable and cost effective. This paper presents first demonstration of 3D optical readout of TPC, using CF4 gas as a proof of principle. Both cosmic rays and an Americium-241 alpha source have been imaged in 100 mbar CF4. A single-photon sensitive camera was developed by combining a Timepix3 (TPX3) based camera with an image intensifier. When a pixel of TPX3 is hit, a packet containing all information about the hit is produced. This packet contains the x,y coordinates of the pixel, time of arrival (ToA) and time over threshold (ToT) information. The z position of the hit in the TPC is determined by combining drift velocity with ToA information. 3D event reconstruction is performed by combining the pixel's x,y location with this calculated z position. Calorimetry is performed using time over threshold, a measure of the intensity of the hit.
View Paper (https://iopscience.iop.org/article/10.1088/1748-0221/14/06/P06001)ARIADNE, a Photographic Two-Phase LAr TPC
2017 A. Roberts
ARIADNE is an ERC funded novel and innovative 1-ton two-phase LAr TPC experiment investigating pho- tographic imaging as an attractive alternative readout method to charge readout that is currently planned for future giant two phase LAr neutrino experiments. Advantages over current readout techniques include reduction or elimination of charge read-out channels as well as ease of scalability, upgrade, installation and maintenance. This technology has already been demonstrated at the Liverpool LAr facility with the pho- tographic imaging of the secondary scintillation light produced in THGEM holes induced by cosmic muon tracks and single gamma interactions using a 40-litre prototype. Results will be presented that demonstrate imaging and linear track reconstruction of cosmic rays using an EMCCD camera. An overview and status of the project will be detailed. ARIADNE will mature and validate photographic readout technology and will be fully characterized at a charged particle beam line at CERN.
View Paper (https://pos.sissa.it/314/802/pdf)Letter of Intent: ARIADNE, a Photographic LAr TPC at the CERN Neutrino Platform
2016 K. Mavrokoridis*, K. J. McCormick, M. Nessi, A. Roberts, N. A. Smith and C. Touramanis
This letter of intent describes a novel and innovative two-phase LAr TPC with photographic capabilities as an attractive alternative readout method to the currently accepted segmented THGEMs which will require many thousands of charge readout channels for kton-scale two-phase TPCs. These colossal LAr TPCs will be used for the future long-baseline-neutrino-oscillation experiments. Optical readout also presents many other clear advantages over current readout techniques such as ease of scalability, upgrade, installation and maintenance, and cost e ectiveness. This technology has already been demonstrated at the Liverpool LAr facility with the photographic capturing of cosmic muon tracks and single gammas using a 40-litre prototype. We have now secured ERC funding to develop this further with the ARIADNE programme. ARIADNE will be a 1-ton two-phase LAr TPC utilizing THGEM and EMCCD camera readouts in order to photograph interactions, allowing for track reconstruction and particle identi cation. We are requesting for ARIADNE to be given time at a charged particle beam within the CERN Neutrino Platform, a facility dedicated to Neutrino detector R&D. This will allow for characterization of calorimetric and particle identi cation capabilities. ARIADNE will mature and validate the photographic readout technology, informing future LAr TPC design.
View Paper (http://cds.cern.ch/record/2123865/files/SPSC-I-244.pdf)First Demonstration of Imaging Cosmic Muons in a Two-Phase Liquid Argon TPC using an EMCCD Camera and a THGEM
2015 K. Mavrokoridis∗, J. Carroll, K. J. McCormick, P. Paudyal, A. Roberts, N. A. Smith, C. Touramanis
Colossal two-phase Liquid Argon Time Projection Chambers (LAr TPCs) are a proposed option for future long-baseline neutrino experiments. This study illustrates the feasibil- ity of using an EMCCD camera to capture light induced by single cosmic events in a two-phase LAr TPC employing a THGEM. An Andor iXon Ultra 897 EMCCD camera was externally mounted via a borosilicate glass viewport on the Liverpool two-phase LAr TPC. The camera successfully captured the secondary scintillation light produced at the THGEM holes that had been induced by cosmic events. The light collection capability of the camera for various EMCCD gains was assessed. For a THGEM gain of 64 and an EMCCD gain of 1000, clear images were captured with an average signal-to-noise ratio of 6. Preliminary 3D reconstruction of straight cosmic muon tracks has been performed by combining the camera images, PMT signals and THGEM charge data. Reconstructed cosmic muon tracks were used to determine THGEM gain and to calibrate the intensity levels of the EMCCD image.
View Paper (http://www.arxiv.org/abs/1507.06586v1)Optical Readout of a Two Phase Liquid Argon TPC using CCD Camera and THGEMs
2014 K. Mavrokoridis∗, F. Ball, J. Carroll, M. Lazos, K. J. McCormick, N. A. Smith, C. Touramanis, J. Walker
This paper presents a preliminary study into the use of CCDs to image secondary scin- tillation light generated by THick Gas Electron Multipliers (THGEMs) in a two phase LAr TPC. A Sony ICX285AL CCD chip was mounted above a double THGEM in the gas phase of a 40 litre two-phase LAr TPC with the majority of the camera electronics positioned externally via a feedthrough. An Am-241 source was mounted on a rotatable motion feedthrough allowing the positioning of the alpha source either inside or outside of the field cage. Developed for and incorporated into the TPC design was a novel high volt- age feedthrough featuring LAr insulation. Furthermore, a range of webcams were tested for operation in cryogenics as an internal detector monitoring tool. Of the range of web- cams tested the Microsoft HD-3000 (model no:1456) webcam was found to be superior in terms of noise and lowest operating temperature. In ambient temperature and atmospheric pressure 1 ppm pure argon gas, the THGEM gain was ≈1000 and using a 1 msec exposure the CCD captured single alpha tracks. Success- ful operation of the CCD camera in two-phase cryogenic mode was also achieved. Using a 10 sec exposure a photograph of secondary scintillation light induced by the Am-241 source in LAr has been captured for the first time.
View Paper (http://www.arxiv.org/abs/1401.0525v2)Argon Purification Studies and a Novel Liquid Argon Re-circulation System
2011 K. Mavrokoridis∗, R. G. Calland, J. Coleman, P. K. Lightfoot, N. McCauley, K. J. McCormick, C. Touramanis
Future giant liquid argon (LAr) time projection chambers (TPCs) require a purity of better than 0.1 parts per billion (ppb) to allow the ionised electrons to drift without significant capture by any electronegative impurities. We present a comprehensive study of the effects of electronegative impurity on gaseous and liquid argon scintillation light, an analysis of the efficacy of various purification chemicals, as well as the Liverpool LAr setup, which utilises a novel re-circulation purification system. Of the impurities tested - Air, O2, H2O, N2 and CO2 in the range of between 0.01 ppm to 1000 ppm - H2O was found to have the most profound effect on gaseous argon scintillation light, and N2 was found to have the least. Additionally, a correlation between the slow component decay time and the total energy deposited with 0.01 ppm - 100 ppm O2 contamination levels in liquid argon has been established. The superiority of molecular sieves over anhydrous complexes at absorbing Ar gas, N2 gas and H2O vapour has been quantified using BET isotherm analysis. The efficiency of Cu and P2O5 at removing O2 and H2O impurities from 1 bar N6 argon gas at both room temperature and -130 ◦C was investigated and found to be high. A novel, highly scalable LAr re-circulation system has been developed. The complete system, consisting of a motorised bellows pump operating in liquid and a purification cartridge, were designed and built in-house. The system was operated successfully over many days and achieved a re-circulation rate of 27 litres/hour and high purity.
View Paper (http://www.arxiv.org/abs/1106.5226v1)