Tests of LM2 MicroMegas Modules on Cosmic Stand in Dubna

In 2018, Dubna team assembled the first LM2 module for ATLAS New Small Wheel upgrade. Assembled modules have to pass quality and performance tests on-site including geometry, gas leaking, high voltage and MIP registration efficiency measurement on cosmic stand. The latter is important not only as the measurement by itself but also as an extention of HV test and a check of mere possibility for correct readout boards installation. Cosmic tests started with a severe handicap - a lack of readout boards to fully populate the module with a following consequences: First an algorithm was developed to measure efficiency in a single point of 1 layer in a module using reconstructed probe tracklet in 3 other layers of the same module, so called "module self-testing" compared to other imaginable scenarios where the probe track is provided by another LM2 module or MDT chamber or another precision tracking system. While giving a 2-D map of efficiency for each of 4 layers this method has limitations which are discussed. Next a specific installation method for both compression bars and readout cards was developed. It saves precious readout cards from mechanical damage which accumulates over time as the cards were reinstalled 3 times per module in 2019 and 2 times per module in 2020. Also it allows for easier and more regular installation process which was considered as fully "expert-mode" but now allowed for trainees with only a few expert interventions. Cosmic stand setup description, installation technique details, example plots of efficiency and signal amplitude distributions over panel area, HV turn-on curves and efficiency pressure dependence are included.