Performance of large-size streamer tubes operated with argon-ethane mixture

A study of the performance of large-size (3 cm2) streamer tubes operated with argon/ethane gas mixtures has been carried out. Unlike previous results obtained with small-size (1 cm2) streamer tubes, stable operation is achieved when gas mixtures with an ethane fraction greater than 70% are used. The use of ethane replacing isobutane allows one to avoid problems due to the low vapour pressure of this gas. Thus, owing to their high mechanical and electrical reliability and their low cost, the operation of these streamer tubes in large patches addressed to the detection of the EAS muon component could be envisaged.