Stability studies of sealed (zero gas flow) resistive plate chambers

Abstract

The phase-out of hydro-fluorocarbons, owing to their high Global Warming Potential, affecting the main gas used in Resistive Plate Chambers (RPCs), tetrafluoroethane C${}_2$H${}_2$F${}_4$, has increased operational difficulties on existing systems and imposes strong restrictions on its use in new systems.

This has motivated a new line of R&D on sealed RPCs: RPCs that do not require a continuous gas flow for their operation and dispense the use of very complex and expensive re-circulation and/or recycling gas systems.

In this work, we demonstrate the feasibility of a small telescope for atmospheric muon tracking consisting of four 300 × 300 mm${}^2$ sealed RPCs with gas gap widths of $1\mathrm{mm}$, $1.5\mathrm{mm}$ and $2\mathrm{mm}$. The results suggest that it is possible to operate this type of detectors for extended periods of time (more than five months) with its main characteristics, efficiency, average charge and streamer probability, without apparent degradation and similar to a RPC operated in continuous gas flow.

However, this paper does not prove that sealed RPC can cover all fields of application normally attributed to RPCs. Much more testing would be needed to prove that sealed RPCs can be used in other conditions, especially at high rate and for extended periods of operation and large scales, like e.g. in LHC experiments at CERN.