Performance of drift tubes under high radiation

Abstract

In this thesis, the aging and the rejuvenation of an ATLAS proportional drift tube are described. Firstly, the Diethorn model of gain is tested using pressure and sense-wire voltage measurements. The drift tube was then aged using P10 gas (Ar:CH₄ 90:10) and a small amount of Si oil vapor, with a tube section of radius [approx.] 1 cm being subjected to UV radiation. An aging current of 30[mu]A was maintained and after the accumulation of 21 coulombs on the wire, the tube gain decreased to less than 70%. Subsequently, the tube was rejuvenated by the treatment with Ar:0₂ 99:1 gas, at reverse wire potential and an reverse "rejuvenation" current of 30[mu]A. Rejuvenation was successful after the accumulation of the equivalent of 3C from this current.