ATLAS’s MDT Noise fluctuations, and the measurement of Background Radiation

Atlas will suffer from Photon and Neutron radiation in the cavern. This background radiation is one of the main reasons for the necessary upgrade of ATLAS’s MDT, to cope with higher luminosity. The MDT Neutron sensitivity is ∼ 5 ·10−4, The Photon sensitivity is ∼ 8 ·10−3. The Radiation Task Force[1], predicted, that at Luminosity of 1034cm−2s−1, the Background radiation-noise rate, is described in figure 1. When the LHC beam will be on, these prediction will have to be measured and verified (With the necessary scaling down of 103 to the luminosity). One possible way to do it is using the data recorded in the MDT. In the MDT, The Average expected counting rate per tube due to electronic Noise,without background, is a few 100s Hz. Example of expected counting rate per tube due to radiation at luminosity of 1031cm−2s−1 in the some cham-bers: (Scaling from 1034cm2s−1 predictions, a typical number, may vary for different chambers of the same station) • BOL 18 Hz/Tub