The lifetime of drift tubes operated with Ar-CH4-N-2 91-5-4, Ar-CH4-N-2-CO2
94-3-2-1, Ar-CF4-N-2-CO2 94.5-0.5-2-3 and Ar-CO2 80-20 is studied under va
rious conditions. H2O and ethanol were successfully tested as a remedy agai
nst ageing.
The method of glow discharge in argon is used to clean the cathode and inef
ficient wires and first results of this treatment are presented. (C) 1998 E
lsevier Science B.V. All rights reserved.