A lot of effort has been invested in the development of the
Microstrip Gas Chamber (MSGC) in order to be used as
tracker
for the LHC project. This technique allows good localization
accuracy and double track resolution. However, it is necessary
to operate it with a relatively low gas gain because of the
presence of the insulator near the amplification region and
because of the fragility of the structure. Recently a new
preamplification structure, called GEM has been introduced
which can give an additional gas gain, and compensates the lack
of gain of the original MSGC. Other concepts of novel
proportional counters have been proposed recently: CAT,
MICRO-DOT. A review of recently developed gaseous detectors
can be found in reference. MICROMEGAS is a high gain
gaseous detector, which can stand up alone without a need of
an additional preamplification. It combines high accuracy,
high rate capability, excellent timing properties and
robustness.
These results were confirmed by a similar structure having
wider amplification gap and thicker metallic grid.