T2K ND280 Upgrade -- Technical Design Report

TL;DR

This paper details the technical design and upgrades of the T2K ND280 detector, aiming to enhance neutrino interaction measurements and reduce uncertainties for improved physics outcomes in the T2K-II project.

Contribution

It introduces new detector components and design modifications to improve measurement precision and reduce systematic uncertainties in neutrino experiments.

Findings

Successful test-beam data collection in 2018

Enhanced detector granularity and coverage

Projected reduction of event prediction uncertainties to 4%

Abstract

In this document, we present the Technical Design Report of the Upgrade of the T2K Near Detector ND280. The goal of this upgrade is to improve the Near Detector performance to measure the neutrino interaction rate and to constrain the neutrino interaction cross-sections so that the uncertainty in the number of predicted events at Super-Kamiokande is reduced to about 4%. This will allow to improve the physics reach of the T2K-II project. This goal is achieved by modifying the upstream part of the detector, adding a new highly granular scintillator detector (Super-FGD), two new TPCs (High-Angle TPC) and six TOF planes. Details about the detector concepts, design and construction methods are presented, as well as a first look at the test-beam data taken in Summer 2018. An update of the physics studies is also presented.