Improving the robustness of Micromegas detector with resistive DLC anode for the upgrade of the TPC readout chambers of the MPD experiment at the NICA collider

Abstract

A prototype of the Micromegas detector with 30 × 30 mm2 active area and the resistive anode was developed and produced at DLNP JINR using a bulk Micromegas technological process and a diamond-like carbon resistive layer on a polyimide substrate. The prototype is considered as an option for the future upgrade of the readout chambers for the Time Projection Chamber of the Multi-Purpose Detector experiment at the NICA collider. The performance of the prototype of the Micromegas detector was studied using a 55Fe radioactive source and an Ar:CO2 (90:10) gas mixture. The dependencies of the gas gain and the energy resolution on applied high voltage are obtained. The detector works stably up to the gas gain of 30,000. For the gas gain of 10,000 the resolution for the line 5.9 keV of the 55Fe source is 22%. The robustness of the detector prototype to electric discharges was demonstrated by accumulating about 10,000 discharge events at a gas gain of 40,000 without any visible impact on the operation of the prototype.