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Description
Resistive Plate Chambers (RPC) made of both glass and bakelite plates are under test and characterization processes as part of the detail R&D work for the ICAL detector setup of India-based Neutrino observatory [1]. A uniform response from the whole chamber is an important requisite for large area coverage (∼ 100,000 m2 ) of the ICAL which along with the large mass (∼ 50 kiloton) will help to achieve statistically significant number of neutrino interactions. Therefore, a numerical simulation has been conducted to study the electric field configuration of the chamber which is the key factor in the detector response dynamics. In order to carry out a detailed numerical simulation, the RPC has been modeled with its components in realistic terms of dimension, material and artifacts. For example, the inner surfaces of the bakelite plates which enclose the gas volume of RPC have been found to exhibit roughness of the order of 2 μm with standard deviation of about 350 nm. Asperities are also observed around the junctions of button spacers and electrodes due to leakage of glue. The desired uniform electric field within the gas volume of RPC is expected to be modified locally due to presence of these surface features, which will eventually affect the response from the detector. In the present study, the complex surface topology has been modeled using different statistical distributions of asperities of different shapes and sizes and their effect on the field map has been simulated. The calculations have been performed using COMSOL Multiphysics [2], a software based on finite element method and neBEM [3], a field solver based on boundary element method. Preliminary results on the effect of rough surface on the RPC response will be presented in the workshop. References: [1] ICAL collaboration, arXiv:1505.07380, 27/05/2015. [2] COMSOL : a multiphysics simulation tool, www.comsol.co.in [3] N. Majumdar and S. Mukhopadhyay, 2007 JINST 2 P09006.
