The micro-Resistive WELL detector: a compact spark-protected single amplification-stage MPGD

Abstract

In this work we present a novel idea for a compact spark-protected single amplification stage Micro-Pattern Gas Detector (MPGD). The detector amplification stage, realized with a structure very similar to a GEM foil, is embedded through a resistive layer in the readout board. A cathode electrode, defining the gas conversion/drift gap, completes the detector mechanics. The new structure, that we call Resistive-WELL (R-WELL), has some characteristics in common with previous MPGDs, such as C.A.T. and WELL, developed more than ten years ago. The prototype object of the present study has been realized in the 2009 by TE-MPE-EM Workshop at CERN. The new architecture is a very compact MPGD, robust against discharges and exhibiting a large gain (∼6×10 3 ), simple to construct and easy for engineering and then suitable for large area tracking devices as well as huge calorimetric apparata.

Performance of μ-RWELL detector vs resistivity of the resistive stage

“…One of the major difference of such detectors with respect to the first version of the μ-RWELL [1] is that the copper dots, patterned on the bottom side of the foil in correspondence of each WELL structure, have been removed thanks to the use of the DLC that ensures a high chemical and mechanical stability. Moreover a global irradiation test at the GIF++ CERN facility is in progress to study possible aging effects on the DLC.…”

“…The μ-RWELL has been introduced as a thin, simple and robust detector for very large area applications requiring the operation in harsh radiation environment [1]. The detector, as sketched in Fig.…”

“…This mechanism strongly suppressing the discharge amplitude (down to few tens of nano-ampere [1]) gives the possibility to achieve large gains with only one amplification stage.…”

“…A drawback, strictly correlated with the Ohmic behavior of the detector is the reduced capability to be efficiently operated in high particle fluxes [1].…”

Advances on micro-RWELL gaseous detector

“…The introduction of a thin resistive layer coupled with the readout [1] stands for a deep innovation in this field, providing a protection to the front-end electronics once the discharge occurs [2]. The detector described in this work enters the subset of the resistive MPGD, combining its stability under heavy irradiation with a very easy assembly procedure: the micro-Resistive WELL (µ-RWELL) [3]. Actually the detector is composed of just two active elements: an amplification stage (µ-RWELL_PCB) and a cathode defining the drift/conversion gas gap ( fig.…”