Production and performance study of Diamond-Like Carbon resistive electrode in MPGD

Abstract

Diamond-Like Carbon (DLC) is a class of metastable amorphous carbon material that contains both diamond-structure and graphite-structure. DLC provides a new method to produce high-quality resistive materials for Micro-Pattern Gaseous Detectors (MGPDs) owing to its excellent properties, including availability of a wide range of resistivity with good control and good chemical stability. DLC production with magnetron sputtering technique has been studied, and different resistive materials based on DLC coating have been produced and tested in various MPGDs. The surface resistivity of DLC coating can vary from 5 MΩ/sq to 100 GΩ/sq with good control by adjusting the coating thickness and Hydrogen doping. The uniformity of surface resistivity is better than 15% over an area of 15 cm × 15 cm and about 23% over 25 cm × 25 cm. This paper describes the DLC coating technique and characterization of surface resistivity of the coating. A few examples of application of DLC-based resistive materials in MGPDs are also presented. Among them are two types of DLC resistive electrodes with different structures used in micro-Resistive WELL detectors, THGEMs with DLC coating on the dielectric surface to remove the charging-up effect, DLC coated Cherenkov radiators to serve as a radiation-hard photocathode in Picosecond Micromegas detector.