PoS - Proceedings of Science
Volume 390 - 40th International Conference on High Energy physics (ICHEP2020) - Parallel: Neutrino Physics
The T2K ND280 Upgrade
D. Sgalaberna* On behalf of the T2K collaboration
*corresponding author
Full text: pdf
Pre-published on: January 29, 2021
Published on:
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 reaching sensitivity for 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 combined statistical and systematic uncertainties to better than 4\%.
We have developed an innovative concept for this neutrino detection system, comprising the 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 approximately $~1.9\times1.9\times0.6~\text{m}^3$ and a total mass of about 2 ton. It consists of about 2 millions small scintillator cubes each $1~\text{cm}^3$. Each cube is optically isolated. The signal readout from each cube is provided by wavelength shifting fibers inserted through the cubes and connected to micro-pixel avalanche photodiodes MPPCs. The total number of channels will be $\sim$60,000. We have demonstrated that, by providing three 2D projections, this detector delivers excellent PID, timing, and tracking performance, including a $4\pi$ angular acceptance, especially important for short proton and pion tracks.
The HA-TPC will be used for 3D track reconstruction, momentum measurement and particle identification. These TPCs, with overall dimensions of $2\times2\times0.8~\text{m}^3$, will be equipped with 32 resistive Micromegas. 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 $34\times42~\text{cm}^2$ resistive bulk Micromegas will use a 500 kOhm/square DLC foil to spread the charge over the pad plane, each pad being appr. $1~\text{cm}^2$. The front-end cards, based on the AFTER chip, will be mounted on the back of the Micromegas and parallel to its plane.
The time-of-flight (TOF) detector will allow to reject events generated in the passive areas of the detector and improve particle identification. The TOF will consist of 6 planes with about $5~\text{m}^2$ surface area surrounding the SuperFGD and the TPCs. Each plane will be assembled with 2.2 m long cast plastic scintillator bars with light collected by arrays of large-area MPPCs from two ends. The time resolution at the bar centre is 150 ps.
A report on the design of these detectors, their performance, the results of the test beam and the plan for the construction is provided.
How to cite

Metadata are provided both in "article" format (very similar to INSPIRE) as this helps creating very compact bibliographies which can be beneficial to authors and readers, and in "proceeding" format which is more detailed and complete.

Open Access
Creative Commons LicenseCopyright owned by the author(s) under the term of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.