Measurement of electrical properties of electrode materials for the bakelite Resistive Plate Chambers

Abstract

Single gap (gas gap 2 mm) bakelite Resistive Plate Chamber (RPC) modules of various sizes from 10 cm \times 10 cm to 1 m \times 1 m have been fabricated, characterized and optimized for efficiency and time resolution. Thin layers of different grades of silicone compound are applied to the inner electrode surfaces to make them smooth and also to reduce the surface resistivity. In the silicone coated RPCs an efficiency > 90% and time resolution \sim 2 ns (FWHM) have been obtained for both the streamer and the avalanche mode of operation. Before fabrication of detectors the electrical properties such as bulk resistivity and surface resistivity of the electrode materials are measured carefully. Effectiveness of different silicone coating in modifying the surface resistivity was evaluated by an instrument developed for monitoring the I-V curve of a high resistive surface. The results indicate definite correlation of the detector efficiency for the atmospheric muons and the RPC noise rates with the surface resistivity and its variation with the applied bias voltage. It was also found that the surface resistivity varies for different grades of silicone material applied as coating, and the results are found to be consistent with the detector efficiency and noise rate measurements done with these RPCs.

9 Pages, 6 figures

References in corpus (1)

• Performances of silicone coated high resistive bakelite RPC

Cited by in corpus (6)

• First studies with the Resistive-Plate WELL gaseous multiplier
• Characterization of 3 mm Glass Electrodes and Development of RPC Detectors for $INO-ICAL$ Experiment
• Study of RPC bakelite electrodes and detector performance for INO-ICAL
• Fabrication and Characterisation of Oil-Free Large High Pressure Laminate Resistive Plate Chamber
• A new type of RPC with very low resistive material
• Characterization and Comparison of Glass Electrodes