Speaker
Description
Accumulation of space-charge in gaseous ionization detectors is a well-known phenomenon. Various signatures of its effects are observed experimentally in all sorts of gaseous detectors, starting from wire chambers, RPCs to MPGDs [1,2,3,4,5]. It is also known to have important consequences influencing avalanche to streamer transition [6], loss of efficiency and response uniformity [7] in many of these detectors. As a result, study of space-charge accumulation is a topic of great interest since long. However, since the process occurs very gradually with little effect in the initial phases, it is difficult to track the evolution of the space-charge accumulation by experimental means [8]. Numerical modelling using particle models faces insurmountable problems due to the fact that the charge accumulation occurs over a large number of events and incorporation of space charge effects through all these events becomes computationally intensive [9,10]. Fluid modelling such as those pursued in [11,12], on the other hand, does not seem to have explored the possibility of simulating multiple events to any great extent.
Since suitably large computational resources necessary to carry out relevant particle model simulations may be beyond the reach of the average user [13,14], we have worked with fluid models to investigate the problem at hand. In this presentation, we report results on space-charge accumulation and its effects in several gaseous detectors (RPC, THGEM) by carrying out multiple-event simulations based on fluid models.
As a representative result, in Figure 1, we have shown the progress of a sequence of primary electrons towards the readout anode of a THGEM detector using Ar-CO2 gas mixture in volumetric ratio of 90:10. The primaries have been generated assuming the application of a 55Fe radioactive isotope. Moreover, for this computation, the geometry of the detector has been considered axisymmetric.
References:
[1] D.D. Ryutov, S. Hau-Riege, R.M. Bionta, Space-charge effects in a gas detector, SLAC-TN-10-043, September 28, 2007
[2] Christian Lippmann, Werner Riegler, Space charge effects in Resistive Plate Chambers, Nucl. Instr. And Meth. in Phys. Res. A, Volume 517, Pages 54-76, 21 January 2004
[3] Maximilien Alexandre Chefdeville, Development of Micromegas-like gaseous detectors using a pixel readout chip as collecting anode, Ph. D. thesis, University of Amsterdam and University of Paris Sud, 2009.
[4] Purba Bhattacharya, Experimental and Numerical Investigation on Micro-Pattern Gas Detectors, Ph. D. thesis, University of Calcutta, 2014.
[5] Antonio Bianchi, R&D studies on ageing and on environment-friendly gas mixtures for the Resistive Plate Chambers of the ALICE muon system, Ph. D. thesis, Università degli Studi di Torino, 2020.
[6] J.T.Kennedy, Study of the avalanche to streamer transition in insulating gase, Phd Thesis, Technische Universiteit Eindhoven, 1995.
[7] L Shekhtman, Micro-pattern gaseous detectors, Nucl. Instr. And Meth. in Phys. Res. A, Volume 494, Pages 128-141, 21 November 2002.
[8] P. Abratenko et al, Measurement of space charge effects in the MicroBooNE LArTPC using cosmic muons, JINST, 15, P12037, 2020.
[9] Promita Roy, Prasant Kumar Rout, Jaydeep Datta, Purba Bhattacharya, Supratik Mukhopadhyay, Nayana Majumdar, Sandip Sarkar, Study of space charge phenomena in GEM-based detectors, Nucl. Instr. And Meth. in Phys. Res. A, Volume 1047, 167838, February 2023.
[10] Tanay Dey, Purba Bhattacharya, Supratik Mukhopadhyay, Nayana Majumdar, Abhishek Seal, Subhasis Chattopadhyay, Parallelization of Garfield++ and neBEM to simulate space-charge effects in RPCs, Computer Physics Communications, Volume 294, 108944, January 2024
[11] P.K. Rout, R. Kanishka, J. Datta, P. Roy, P. Bhattacharya, S. Mukhopadhyay, N. Majumdar and S. Sarkar, Numerical estimation of discharge probability in GEM-based detectors, JINST, 16, P09001, 2021.
[12] Purba Bhattacharya, Rishabh Gupta, Shounok Guha, Prasant Kumar Rout, Jaydeep Datta, Nayana Majumdar and Supratik Mukhopadhyay, Study of charge dynamics in THGEM-based detectors — a numerical approach, JINST, 20, C04019, 2025.
[13] O. Bouhali, A. Sheharyar, and T. Mohamed, Accelerating avalanche simulation in gas based charged particle detectors, Nucl. Instr. and Meth. in Phys. Res. A, 901, 92-98, 2018.
[14] Shubhabrata Dutta, Purba Bhattacharya, Tanay Dey, Nayana Majumdar, Supratik Mukhopadhyay, Numerical simulation of space charge effects in MPGDs, presented in MPGD 2024 and under review in JINST.
| Workshop topics | Sensor materials, device processing & technologies |
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