  In this paper, the effect of humidity and dust trapped in avalanche region on
leakage current of bulk micro-MEGAS detector is studied. Pyralux PC1025 layers
of DuPont are introduced in bulk technique and micro-MEGAS detector with
pillars of 300{\mu}m in diameter is fabricated. Leakage current is tested in
air with different humidity. Silicon carbide powder and PMMA (polymethyl
methacrylate) powder are added as dust to avalanche region. Leakage current
with and without powder is tested in air and results are depicted in the same
figure. Test results indicate that leakage current increases with both storage
humidity and test humidity, and also increases when powder is introduced in
avalanche region.

Instrumentation and Detectors