Time Projection Chambers for the T2K near detector

Abstract

T2K is a long baseline neutrino experiment aiming primarily at the measurement of the mixing angle θ13 through the observation of vμ ⟩ ve oscillations between the JPARC accelerator complex and the Super Kamiokande detector. A near detector, called ND280 and located 280 m from the neutrino production target, will be used to measure the neutrino energy spectrum, flavour content and interaction rates of the un-oscillated beam and hence to predict the neutrino interactions at Super Kamiokande. ND280 is a magnetized off-axis tracking detector that includes as key detector elements three large Time Projection Chambers (TPCs) that will play a crucial role in the measurement of the momentum, charge and identity of charged particles. The T2K TPCs are now being constructed and will be commissioned at JPARC at the end of 2009. These detectors use gaseous micro-pattern devices which are based on the novel bulk-MicroMegas technology. Design and construction aspects of the T2K TPCs are presented together with the expected detector performances. Recent tests of bulk-MicroMegas prototypes are discussed as well as the performance obtained with the TPC front-end electronics based on the new AFTER ASIC.