Conductivity and charge depletion aging of resistive electrodes for high rate RPCs

Abstract

Development of new electrodes is the key element for the improvement of the high rate Resistive Plate Chambers (RPC). In the particular case of resistive electrodes, the fabrication of these devices is a challenging problem from a material science point of view. The combination of resistivity, permittivity and stability requirements is really hard to satisfy for any known material. Respecting this, several materials have been found to be suitable for fabrication of resistive plates. In this work, we have carried out electrical characterizations of some of these materials that are currently used in RPCs or are solid candidates to be used as resistive plates for high rate RPCs. As a result, we have found strong evidences that ion conduction processes under moderate to high electric fields are able to drift high amounts of charge which are crucial to understand the degradation nature of the involved processes.

First results of Resistive-Plate Well (RPWELL) detector operation at 163 K

“…We report here on the first successful operation of an RPWELL detector having a resistive plate made of ferric-based (Fe 3+ ) ceramic composite ("Fe-ceramic") [42] at LXe temperature; at 163K, close to the triple point of Xe, with the resistivity tuned to a suitable value at this temperature. The results of the search for appropriate resistive materials are briefly summarized.…”

“…exponential increase in resistivity with decreasing T. As shown in Figure 2, the Semitron and LRS glass plates have resistivity values ∼10 14 Ω·cm at 200 K; they behave as insulators at lower temperatures, rendering them unsuitable for RPWELL operation in LAr and LXe. One of the remarkable advantages of the robust Fe-Ceramics [42], developed for Resistive-Plate Chambers, are their tunable electrical properties. The ability to tune their electric resistivity by post-processing treatments at 500 to 800 • C, to be within the range ∼10 9 -10 12 Ω·cm at LXe and LAr temperatures, makes them an excellent candidate as a resistive plate for cryogenic RPWELL and other resistive gas-avalanche detectors.…”

“…The resistance R was calculated by a linear fit to the I-V curve, for materials exhibiting Ohmic behavior. Measurements were performed in a vacuum chamber (held at 10 One of the remarkable advantages of the robust Fe-Ceramics [42], developed for Resistive-Plate Chambers, are their tunable electrical properties. The ability to tune their electric resistivity by post-processing treatments at 500 to 800 • C, to be within the range ∼10 9 -10 12 Ω•cm at LXe and LAr temperatures, makes them an excellent candidate as a resistive plate for cryogenic RPWELL and other resistive gas-avalanche detectors.…”

Study of glass properties as electrode for RPC

“…where, ε p and ε g are the permittivities, and E p and E g are the electric fields of the electrode plate and the gas gap, respectively [7]. Equation 3.1 indicates that the RPCs made out of electrodes with larger relative permittivity can be operated at lower bias voltages.…”

Cryogenic RPWELL: a novel charge-readout element for dual-phase argon TPCs

“…The properties of the RPWELL detector were assessed also at liquid xenon (LXe) temperature, 163 K, in gaseous Ne:5%CH 4 [26]. The resistive plate was made of a ferrite ceramic [27] of bulk resistivity 𝑅 V ≈ 10 11 Ω•cm at 163 K, showing discharge quenching capabilities also at this cryogenic conditions. To explore the possibility of operating an RPWELL at liquid argon temperature, 90 K, a major challenge was to find or engineer appropriate materials having the aforementioned bulk resistivity.…”