Advanced aging study on Triple GEMs for CMS GE2/1 and ME0

After several years of successful R&D with Gas Electron Multipliers (GEM) based detectors, the CMS GEM collaboration is going to install the innermost region of the forward muon spectrometer of the Compact Muon Solenoid (CMS) experiment with the triple-GEM technology. In this work a new concept of aging study is proposed and performed with the goal to better understand the aging issues in contaminated gas mixtures and in a densely ionizing particles environment. To our knowledge, no such test is present in literature. This test, on a $10\times10\ cm^2$ triple-GEM prototype, is in course at CMS - GEM QA/QC lab. The aim is to better understand if there are new, ever studied, outgassing issues and to comprehend if particles, with different specific ionization, may induce aging effects which were not present in the previous X-rays and $\gamma$-rays studies. The prototype is irradiated in two different regions at the same time with two different types of source: a $5.5\ MeV$ alpha emitter ($^{241}Am$) and $5.9 \ keV $ X-ray source ($^{55}Fe$), to investigate if different behaviors in the two areas develop. The contaminants are released in the gas by fluxing it in a heated box containing the material under test. Also a Single Wire Proportional Chamber with polluted gas is irradiated with an X-rays source in order to monitor the effects of the polymerization.