Development and operational experience of magnetic horn system for T2K experiment

TL;DR

This paper details the design, construction, and four-year operational experience of the T2K magnetic horn system, which successfully operated at high current and power levels, enabling significant neutrino oscillation discoveries.

Contribution

It presents the first comprehensive account of the T2K magnetic horn system's design, construction, and operational performance over four years.

Findings

Successful operation at 320 kA pulsed current

No significant damage over 12 million pulses

Enabled discovery of neutrino oscillation phenomenon

Abstract

A magnetic horn system to be operated at a pulsed current of 320 kA and to survive high-power proton beam operation at 750 kW was developed for the T2K experiment. The first set of T2K magnetic horns was operated for over 12 million pulses during the four years of operation from 2010 to 2013, under a maximum beam power of 230 kW, and $6.63\times10^{20}$ protons were exposed to the production target. No significant damage was observed throughout this period. This successful operation of the T2K magnetic horns led to the discovery of the $\nu_{\mu}\rightarrow\nu_e$ oscillation phenomenon in 2013 by the T2K experiment. In this paper, details of the design, construction, and operation experience of the T2K magnetic horns are described.