Results from the 2003 beam test of a MDT BIL chamber: systematic uncertainties on the TDC spectrum parameters and on the space-time relation

In summer 2003, a Monitored Drift Tube chamber of type BIL has been exposed to a 100 GeV muon beam in the X5 area at CERN. The chamber was installed on a rotating support in the Gamma Irradiation Facility GIF, where a $^{137}$Cs radioactive source irradiates the detectors with an intense photon flux. A system of lead filters that can be moved in front of the source allows the users to tune the intensity of the flux. Detailed studies on the determination of the TDC spectrum parameters were performed, also as a function of the background conditions. The rotating support allowed to change the angle of the chamber with respect to the beam. The set of data taken at different orientation was used to perform a preliminary analysis of the conventional autocalibration procedure in absence of background.