The long baseline neutrino experiment T2K has launched the upgrade project of its near detector ND280, crucial to reduce the systematic uncertainty to less than 4%. An essential component of this upgrade consists of the resistive Micromegas TPCs, for 3D track reconstruction, momentum measurement and particle identification. These TPC, with overall dimensions of 2x2x0.8 m3, will be equipped with 32 resistive bulk Micromegas.
The thin field cage (3cm thickness, 4% rad. length) will be realized with laminated panels of Aramid and honeycomb covered with a kapton foil with copper strips. The 34x42 cm2 Micromegas will use a 500 kOhm/square DLC foil to spread the charge over the pad plane, each pad being appr. 1 cm2 . The front-end cards, based on the AFTER chip, will be mounted on the back of the Micromegas and parallel to its plane.
In Summer 2018 we have tested one resistive Micromegas detector on the ex-Harp TPC field cage in the CERN PS test beam (electrons, pions and protons with momenta between 0.5 and 2 GeV/c) with excellent results both for the space point resolution and for dE/dx. In particular we have tuned the charge spreading by varying the electronics shaping time from 100 to 600 ns.
In November 2018 we will release the detailed TDR describing all the components of this device (the installation is planned in 2021). In this talk we will report on the design of this detector, its performance, the results of the test beam and the plan for its construction.