[Paper Review] Assembly, test and analysis development of the T2K upgrade

K. Abe, H. Aihara+382 more|Lancaster EPrints (Lancaster University)|Jan 11, 2019

Neutrino Physics Research61 references77 citations

TL;DR

This Technical Design Report details the ND280 upgrade for the T2K near detector, aiming to improve neutrino interaction measurements and reduce uncertainties to about 4% for Super-Kamiokande predictions.

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.

Motivation & Objective

• Motivate improvements to the near detector to constrain neutrino interaction cross-sections.
• Describe the conceptual and mechanical design of the Super-FGD, High-Angle TPCs, and TOF planes.
• Explain production, assembly, and quality-control methods for detector components.
• Present test-beam data from Summer 2018 to validate concepts and performance.
• Update physics studies to reflect the upgraded detector capabilities.

Proposed method

• Describe the detector concepts and overall design for the ND280 upgrade.
• Detail the production, assembly, and mechanical interfaces of the Super-FGD scintillator cubes and associated electronics.
• Outline the MPPC readout, wavelength shifting fibers, and optical interfaces used in the scintillator system.
• Present the High-Angle Time Projection Chamber design, gas system, field cage, and mechanical simulations.
• Summarize prototype results and test-beam data to validate performance.
• Provide an update to physics studies with the upgraded detector framework.

Experimental results

Research questions

• RQ1 What performance improvements does the ND280 upgrade deliver for measuring neutrino interaction rates?
• RQ2 How does the Super-FGD scintillator target and associated readout affect calibration and cross-section constraints?
• RQ3 What are the key mechanical, electrical, and optical challenges in assembling the upgrade components and how are they addressed?
• RQ4 How do prototype and test-beam results inform the final detector design and operation?
• RQ5 To what extent will the upgrade reduce the uncertainty in predicted Super-Kamiokande event rates?

Key findings

• The upgrade targets reducing the uncertainty in Super-Kamiokande predictions to about 4%.
• A new highly granular scintillator detector (Super-FGD) is developed along with two High-Angle TPCs and six TOF planes.
• Prototype testing and first beamline data (Summer 2018) provide validation for light yield, crosstalk, timing, and particle response.
• The document presents production, assembly methods (including fishing line and alternative methods) for scintillator cubes and their integration with MPPC readout.
• Detailed design and scheduling considerations cover box mechanics, optical interfaces, and DAQ for the upgraded system.