PPT Slide
FINUDA straw tubes detector employees 2424 aluminized-mylar straws (15 mm diameter, ~2.5 m long, ~1 m3 volume) operated with a fixed mixture of argon and ethane (50/50) at a rate of 2m3/day.
The gas system is FULL PARALLEL. Gas mixture, in fact, feeds in parallel 6 layer distributors, each providing gas to groups of 404 straws.
Each straw has an impedance made of stainless steel capillarity
Precise mass flow controllers have an accuracy of 1% of full scale.
BridgeVIEW programs allow to set gas flow values on mass flow controllers on each layer and to monitor the system.
Flow values, temperatures and pressures are collected and can be analyzed off-line.