Automatic test-bench for GEM detectors

The paper describes construction of a scalable, automatic measurement system to research GEM detectors. The testbench enables concurrent and precise measurements of many discharge current signals originating from the charges generated by the avalanche process in gas in the GEM micro-holes where the electric field gradient is high. We used Tektronix scopes MSO/DPO4104 and MSO/DPO5104 and Matlab to collect and process the data. Construction of the test-bench is presented in terms of hardware and software. The examples of lab condition measurements were presented. Analysis of these data enable the estimation of the quality of the GEM detector.