The T2K experiment and its time projection chambers

The Tokai to Kamioka (T2K) experiment [1] is a long baseline neutrino oscillation experiment located in Japan and its goal is to gain a more complete understanding of the neutrino oscillation parameters. A highly pure muon neutrino beam is directed from the accelerator center JPARC towards the Super-Kamiokande (SK) detector, which is 295 km away. A key element of the design of the T2K facility is the use of an off-axis technique. The main physics goals of T2K are to measure the mixing angle θ13 in a νe appearance experiment and improve the measurement of the atmospheric parameters ∆m 2 23 and θ23 using the νµ disappearance channel. The near detector (ND280), located 280 m away from the target, will measure the neutrino beam properties and the neutrino interaction cross section and kinematics before the oscillation, in order to predict the relevant neutrino interactions at SK. It consistes of a magnet, a Pi-Zero Detector (optimized for measuring the rate of neutral current π0 production), an electromagnetic calorimeter (whose main purpose is to measure the photons produced in ND280), a Side Muon Range Detector (to measure the range of muons that exit the sides of ND280) and a tracker (optimized for measuring the momenta of charged particles). The tracking device consists of a sandwich of three time projection chambers (TPCs) and two fine grained detectors (FGDs) which provide the target material. An overview of the TPC calibration methods and some results from the tests done at CERN to study the performance of the TPC readout modules are presented.