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Gaseous Detectors II

Session chair: Titov , Maxim; Tokanai , Fuyuki
Shortcut: N-14
Date: Wednesday, 20 October, 2021, 9:15 AM - 11:15 AM
Room: NSS - 2
Session type: NSS Session


Click on an contribution to preview the abstract content.

9:15 AM N-14-01

Operation of the CGEM detector (#339)

M. Greco1, 3, G. Cibinetto2, L. Lavezzi1

1 INFN Torino, Torino, Italy
2 INFN Ferrara, Ferrara, Italy
3 University of Torino, Torino, Italy

On behalf of BESIII Italian Collaboration


A ten years extension of the data taking of  BESIII experiment, recently approved, motivated an upgrade program both for the leptonic collider BEPCII and for some of the sub-detectors of the spectrometer. BESIII is a multipurpose spectrometer optimized for physics in the tau-charm energy region.
In particular, the current inner drift chamber is suffering from aging and the proposal is to replace it with a detector based on Cylindrical Gas Electron Multiplier (CGEM) technology to improve both the secondary vertex reconstruction and the radiation tolerance.
The CGEM Inner Tracker will be composed of three coaxial layers of cylindrical triple GEMs, operating in an Ar + iC4H10 (90:10) gas mixture with field and gain optimized to maximize the spatial resolution. The new detector is readout with innovative TIGER electronics produced in 110 nm CMOS technology.
A cosmic telescope instrumented with two out of three layers is in operation in Beijing since January 2020, remotely controlled by Italian groups due to the pandemic situation. A dedicated readout chain was developed for data acquisition.
In this presentation, the general status of the project will be presented with a particular focus on the preliminary results from the cosmic data taking and future plans.

Keywords: GEM detectors, Readout Electronics
9:30 AM N-14-02

Micromegas with high-granularity readout: stability and performance at high particle rates (#192)

F. Petrucci1, 3, M. Alviggi2, 4, M. T. Camerlingo1, 3, V. Canale2, 4, M. Della Pietra2, 4, C. Di Donato5, 4, R. Di Nardo1, 3, P. Iengo4, 6, M. Iodice3, S. Franchellucci1, 7, G. Sekhniaidze4

1 Università Roma Tre, Rome, Italy
2 Università di Napoli Federico II, Naples, Italy
3 INFN Roma Tre, Rome, Italy
4 INFN Napoli, Naples, Italy
5 Università di Napoli Parthenope, Naples, Italy
6 CERN, Geneva, Switzerland
7 University of Geneva, Geneva, Switzerland


Micromegas (MM) are being used as tracking detectors in HEP experiment upgrades. For applications at future accelerator experiments, we are developing the MM technology to increase its rate capability and reach a stable and efficient operation up to particle fluxes of 10 MHz/cm2.

In resistive MM, the anode plane hosts the readout elements overlayed by an insulator and a resistive plane to reduce the spark intensity. We tested several MM prototypes with a high- granularity readout plane, with 1x3 mm2 size pads, and different resistive protection schemas exploiting a pad-patterned layer or two uniform DLC layers.

To cope with the high number of readout channels and allow for the size scalability of the detector avoiding dead areas, we are implementing the integration of the readout electronics in the back of the detector.

We present measurements to assess the optimal resistive schema and preliminary results on the embedded electronics prototype currently under test.

Keywords: Position sensitive particle detectors, Gas detectors, Micro Pattern Gaseous Detectors, Particle tracking.
9:45 AM N-14-03

Neutral Bremsstrahlung emission in xenon (#637)

C. A. O. Henriques1

1 University of Coimbra, LIBPhys, Coimbra, Portugal

on behalf of the NEXT Collaboration


Through the years, neutral bremsstrahlung secondary scintillation in noble gases has been neglected in favor of the excimer-based VUV emission, being this mechanism only recently unveiled in argon. We present evidence of non-excimer-based secondary scintillation in xenon, obtained using both the NEXT-White TPC, at present the largest optical Xe-TPC in operation, and a dedicated setup based on a Gas Proportional Scintillation Counter. The secondary scintillation was measured over 5 order of magnitude for a wide range of reduced electric fields. Significant light production was detected even below the Xe-excitation threshold. Comparison with first-principle calculations allows us to assign this scintillation mechanism to neutral bremsstrahlung. For photon wavelengths below 1000 nm, the neutral bremsstrahlung yield increases from about 10‑2 photon/e-/cm/bar to above 3x10‑1 photon/e-/cm/bar for reduced electric fields of 50 V/cm/bar and 500 V/cm/bar, respectively. For reduced electric fields above 1.5 kV/cm/bar, the neutral bremsstrahlung intensity, around 1 photon/e-/cm/bar, is about two orders of magnitude lower than the conventional excimer-based scintillation.  Despite being fainter, this new source of light emission may interfere with the ability to precisely measure low photon signals in TPCs, or even provide a mean to obtain secondary scintillation signals for discrimination purposes in future single-phase liquid xenon TPCs for neutrino and dark matter physics.

Keywords: Neutral Bremsstrahlung, Time Projection Chamber, Xenon scintillation, Rare event detection
10:00 AM N-14-04

The new generation of THCOBRA structures – performance studies operating in Ne/CH4 (#1399)

A. L. Silva1, A. L. Silva1, P. Carvalho2, F. Leite1, L. Carramate1, R. Nunes1, P. Correia1, L. Nunes1, T. Nunes1, J. Veloso1, P. Carvalho2, F. Leite1, L. Carramate1, R. Nunes1, P. Correia1, L. Nunes1, T. Nunes1, J. Veloso1

1 University of Aveiro, I3N - Physics Department, Aveiro, Portugal
2 NOVA University Lisbon, LIBPhys-UNL – Department of Physics, Caparica, Portugal


MicroPattern Gaseous Detectors (MPGD), such as the Thick COBRA (THCOBRA), allow the determination of the energy and the position of interaction of incident photons, making them appealing for many applications. They have been successfully used for photon counting applications, as wells as Energy Dispersive X-Ray Fluorescence (EDXRF) analysis of cultural heritage and biomedical samples. However, there is still a need for improvement, and following the identification of shortcomings through optical readout studies, a new THCOBRA structure was designed. Here, the principle of operation of the THCOBRA detector and its characteristics are presented, focusing on preliminary studies pertaining to the determination of the absolute charge gain and other performance parameters of the new structure.


This work was partially supported by project PTDC/FIS-AQM/32536/2017 and UID/CTM/50025/2019 through COMPETE, FEDER and FCT (Lisbon) programs, and within the scope of the project i3N, UIDB/50025/2020 & UIDP/50025/2020. P.M.S. Carvalho is grateful to FCT for the PhD grant PD/BD/128324/2017.

The costs resulting from the FCT — Fundação para a Ciência e a Tecnologia, I.P hiring L.F.N.D. Carramate is funded by national funds (OE), in the scope of the framework contract CEECIND/01369/2017.

Keywords: gas detectors, THCOBRA, MPGD, EDXRF, X-ray imaging.
10:15 AM N-14-05

Performance studies on RPC detectors operated with low Global Warming Potential gases (#275)

R. Guida1, B. Mandelli1, G. Rigoletti2

1 CERN, EP/DT, Geneve, Genève, Switzerland
2 Claude Bernard Lyon I, IP2I, Lyon, France


Resistive Plate Chamber (RPC) detectors are widely used at the CERN LHC experiments as muon trigger thanks to their excellent time resolution. They are operated with a gas mixture containing C2H2F4 and SF6, both greenhouse gases with a very high global warming potential. The search of new environmentally friendly gas mixtures is advised to reduce GHG emissions and costs as well as to optimize RPC performance. Several recently available gases with low GWP have been identified as possible replacements for C2H2F4 and SF6. In particular, R-1234ze has been studied as a possible replacement for C2H2F4and several gases like Novec fluoroketones, C4F8O and CF3I were tested as a replacements of both C2H2F4 and SF6. The RPC detectors have been tested in laboratory conditions and few selected mixtures were tested at the CERN Gamma Irradiation Facility, which provides a high energy muon beam combined with an intense gamma source allowing to simulate the background expected at HL-LHC. The performance of RPCs was studied at different gamma rates in a presence of muon beam by measuring efficiency, streamer probability, rate capability, induced charge and cluster size. The studies are being carried on by operating RPCs under gas recirculation with the selected gas mixture and exposed to the intense gamma radiation of GIF++ for evaluating possible long-term aging effects, gas damage due to radiation and compatibility of LHC gas system with new gases.

Keywords: gasesous detectors, RPC, LHC
10:30 AM N-14-06

2D Interleaved Readout Planes for MPGDs (#1202)

B. Azmoun1, S. Aune2, K. Dehmelt4, A. Deshpande4, W. Fan4, P. Garg4, T. K. Hemmick4, M. Kebbiri2, A. Kiselev1, I. Mandjavidze2, C. Perez-Lara5, M. L. Purschke1, M. Revolle3, M. Vandenbroucke3, C. Woody1

1 Brookhaven National Laboratory, Physics Department, Upton, New York, United States of America
2 CEA Saclay, DRF/IRFU/DEDIP, Sacaly, France
3 CEA Saclay, DRF/IRFU/DPHN, Saclay, France
4 Stony Brook University, Department of Physics and Astronomy, Stony Brook, New York, United States of America
5 University of Virginia, Department of Physics, Charlottesville, Virginia, United States of America


One dimensional zigzag-shaped anode strip arrays with large pitch (>1 mm) have been shown to have considerable advantages over similarly pitched straight strips for standard planar MPGDs, including 4-GEM, Micromegas, and mRWELL detectors. Once the geometric parameters of the zigzag are precisely tuned for a specific detector application, the spatial resolution remains approximately flat for very large pitches, up to 3.3mm or more. Additionally, the response of the optimized zigzags along the sensitive coordinate and orthogonal direction are highly uniform without the need for additional corrections. In this paper we extend the concept for enhanced charge sharing for coarse segmentations to the case of a 2D readout. Though some 2D interleaved readouts have already been studied, we propose to rigorously optimize the basic geometric parameters of various interleaved anode structures in order to realize a readout pattern with many attributes of an ideal detector, including a uniform detector response along two arbitrary coordinate axes, excellent position resolution, and a coarse segmentation to reduce the significant costs associated with the readout electronics. X-ray measurements, which demonstrate the viability of this readout scheme as well as beam test results from all three types of MPGDs will be presented at the conference.       

Keywords: MPGD, Charge Sharing, 2D Readout, Zigzag, GEM
10:45 AM N-14-07

Rate performance of μ-RWELL irradiated with high intensity X-rays (#891)

G. Bencivenni1, R. de Oliveira3, G. Felici1, M. Gatta1, M. Giovannetti2, 1, G. Morello1, M. Poli Lener1

1 Istituto Nazionale di Fisica Nucleare (INFN), Laboratori Nazionali di Frascati (LNF), Frascati, Italy
2 Univesità degli Studi di Roma, Dipartimento di Fisica, Roma, Italy
3 CERN, Meyrin, Genève, Switzerland


The μ-RWELL is a single amplification stage resistive Micro-Pattern Gaseous Detector (MPGD). The amplification stage, realized on a 50 μm thick polyimide foil, cladded on one side with 5 μm Cu, is sputtered with Diamond-Like-Carbon (DLC) of the order of 100 nm and then coupled to the readout plane. The top of the polyimide foil is patterned with a dense matrix of blind holes (wells), 70 μm wide and with a 140 μm pitch. The cathode and a 6 mm thick frame define the active volume, filled with argon based gas mixtures. The physical properties of the resistive layer of the detector and its grounding scheme are fundamental to address the detector to applications at different particle rates. In this work we report the results of a detailed study of the rate performance of the various detector layouts irradiated with high intensity X-ray beam. The data compared with a model of the resistive stage of the detector show a good agreement, enabling the use of the model as a powerful tool for the design of the resistive layout.

Keywords: Micro Pattern Gaseous Detector, Particle tracking detectors, X-Ray detectors
11:00 AM N-14-08

Fast neutron spectroscopy with a high-pressure nitrogen-filled large volume spherical proportional counter (#990)

I. Manthos1, I. Giomataris2, I. Katsioulas1, P. Knights1, J. Matthews1, T. Neep1, K. Nikolopoulos1, T. Papaevangelou2, B. Phoenix1, R. Ward1

1 University of Birmingham, School of Physics and Astronomy, Birmingham, United Kingdom
2 CEA-Saclay, IRFU, Gif-sur-Yvette, France


We present a fast neutron spectroscopy system based on a nitrogen-filled, large volume gaseous detector, the Spherical Proportional Counter. The system has been successfully operated up to 2 bar gas pressures. Neutron energy is estimated through measurement of the 14N(n,a)B11 and 14N(n,p)C14 reaction products energy. These reactions have comparable cross sections and Q-values with the 3He(n,p)H3 reaction making nitrogen a good alternative to 3He use for fast neutron detection. Two detectors were built in the University of Birmingham and are currently used for the measurement of fast and thermal neutrons in the University of Birmingham and the Boulby underground laboratory.

AcknowledgmentThis project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreements and no 845168 (neutronSphere) and no 841261 (DarkSphere)
Keywords: Ionizing radiation sensors, Particle measurements, Radiation sensors

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