Speaker
Bo Wang
(IHEP)
Description
In this paper, the effect of dust trapped in avalanche region on the leakage current of standard bulk micro-MEGAS detector is studied. Pyralux PC1025 layers of DuPont are introduced in bulk technique and 30×30mm bulk micro-MEGAS detector is fabricated with pillars of 300μm diameter. Stainless steel woven mesh with pitch of 40μm is used as avalanche electrode. PMMA (polymethyl methacrylate) powder is added artificially as dust to avalanche region after the lithography technique. Leakage current with and without powder is tested in air and results of two detectors are depicted in Fig.1 and Fig.2. The green line in Fig.1 and Fig.2 is the leakage current without powder and the red line is the leakage current with powder. Test results indicate that PMMA powder trapped in avalanche region has obvious effect on leakage current. Fig.1. leakage current test result of detector 1 Fig.2. leakage current test result of detector 2 Preliminary work indicates that leakage current increases when dust is trapped in avalanche region, unfortunately quantitive statistics of dust and the effect has not been revealed, which is being studied in our lab. The effect of different powder dust (CeO2, Al2O3, Fe2O3) with different size is also being studied.
