V. Bayev, K. Afanaciev, S. Movchan, A. Kashchuk, O. Levitskaya, V. Akulich and V. Konovalov
A prototype of the large-scale resistive WEM (Well Electron Multiplier) detector with enhanced discharge robustness was developed, produced and tested. The WEM detector is composed of a perforated board (500 µm thick with drilled holes of 200 µm in diameter and 500 µm in pitch) and resistive anode-readout board with high voltage copper grid on one side (500 µm in pitch and 100 µm in strip width) and readout pads on the other side. The resistive anode was made by coating the high voltage grid electrode with diamond-like carbon (DLC) resistive layer of 100 nm thick with sheet resistance of 30 MOhm/square. To improve the robustness of the large-scale WEM, we insulated the grid electrode with a 50 µm thick microstructured insulator using a photolithography technique with parameters that provide the best detector performance according to simulation in Comsol Multiphysics software.
Preliminary tests revealed stable operation of the developed detector confirming the results of math simulations. The proposed approach allows developing the robust large-area WEM detectors for high-energy physics experiments, which simultaneously have great potential for material sciences, medical imaging, hadron therapy and muon tomography.
