Magnetic shielding for large photoelectron multipliers for the OSIRIS facility of the JUNO detector

TL;DR

This paper describes a cost-effective magnetic shielding design using amorphous alloy ribbons for large photoelectron multipliers in the JUNO detector's OSIRIS facility, effectively reducing Earth's magnetic interference.

Contribution

It introduces a novel magnetic shielding method employing amorphous alloy ribbons, optimizing material use for low-background neutrino detection facilities.

Findings

Effective magnetic shielding achieved with minimal material

Cost-efficient design suitable for low-background experiments

Material mass reduction enhances detector sensitivity

Abstract

We present the technical design and characteristics of the magnetic shield developed for 20" PMTs of the low-background OSIRIS facility. A ribbon of amorphous alloy with the extreme magnetic permeability was used in its design providing the excellent efficiency in screening the Earth's magnetic field with a relatively small amount of the material. The mass of materials is crucial for the construction of low-background facilities from the point of view of radioactive backgrounds. Using amorphous materials is cost-efficient compared to other methods for screening the Earth's magnetic field.