Speaker
Description
In view of the J-PARC program of upgrades of the beam intensity, the T2K collaboration is preparing towards an increase of the exposure aimed at establishing leptonic CP violation at 3 $\sigma$ level for a significant fraction of the possible $\delta_{CP}$ values. To reach this goal, an upgrade of the T2K near detector ND280 will be installed at J-PARC in 2022, with the aim of reducing the overall statistical and systematic uncertainties at the appropriate level of better than 4\%.
We have developed an innovative concept for this neutrino detection system, comprising the totally active Super-Fine-Grained-Detector (SuperFGD), two High Angle TPC (HA-TPC) and six TOF planes.
The SuperFGD, a highly segmented scintillator detector, acting as a fully active target for the neutrino interactions, is a novel device with dimensions of ~2x1.8x0.6 $m^3$ and a total mass of about 2 tons. It consists of about 2 millions of small scintillator cubes each of 1 $cm^3$. The signal readout from each cube is provided by wavelength shifting fibers connected to MPPCs. The total number of channels will be ~60,000 and the cubes have already been produced and assembled in $x-y$ layers.
The HA-TPC will be used for 3D track reconstruction, momentum measurement and particle identification. These TPC, with overall dimensions of 2x2x0.8 m3, will be equipped with 32 resistive MicroMegas (ERAM). The thin field cage (3 cm 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 resistive bulk Micromegas will use a 500 kOhm/square DLC foil to spread the charge over the pad plane, each pad being ~1 $cm^2$. The electronics is based on the AFTER chips.
The time-of-flight (TOF) will consist of 6 planes with about 5 m2 surface area surrounding the SuperFGD and the TPCs. Each plane has been assembled with 2.2 m long cast plastic scintillator bars with light collected by arrays of large-area MPPCs from two ends.
In this talk we will report on the status of the construction of these detectors and their performances obtained in test beams.
| Working group | WG6 |
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