Performance study of new thicker GEM

We constructed a Gas Electron Multiplier (GEM) chamber using a new type of GEM foils with holes etched into a flexible printed circuit board using LASER and then plasma. The effective gas gain in a chamber containing three of the foils was similar to that obtainable using three standard CERN GEM foils. The new etching method allows holes to be made in thicker foils. New GEM foils 100 μ m thick were produced to achieve higher gas gains with a single GEM configuration. The effective gas gain was higher than obtained with a chamber with three standard 50 μ m -thick GEM foils in the same electric fields. Using the new thicker GEM foils allows the chamber to be simpler and, in the near future, cylindrical.