# Infused Ice can Multiply IceCube's Sensitivity

## TL;DR

This paper explores a novel method of enhancing IceCube's sensitivity by infusing wavelength-shifting materials into the ice, potentially doubling photon detection efficiency cost-effectively.

## Contribution

It proposes using infused ice as wavelength-shifting optics within IceCube's drill holes to significantly boost sensitivity, a new approach for neutrino detector upgrades.

## Key findings

- Infusing wavelength-shifting substrate can double sensitivity with a 0.05 increase in refractive index.
- Using drill holes as wavelength-shifting optics is a cost-effective upgrade strategy.
- Sensitivity can be increased by 100% with adequate infusion.

## Abstract

The IceCube Neutrino Observatory is the world's largest neutrino detector with a cubic-kilometer instrumented volume at the South Pole. It is preparing for a major upgrade that will significantly increase its sensitivity. A promising technological innovation investigated for this upgrade is wavelength shifting optics. Augmenting sensors with such optics could increase the photo-collection area of IceCube's digital optical modules, and shift the incoming photons' wavelength to where these modules are the most sensitive. Here we investigate the use of IceCube's drill holes themselves as wavelength shifting optics. We calculate the sensitivity enhancement due to increasing the ice's refractive index in the holes, and infusing wavelength-shifting substrate into the ice. We find that, with adequate wavelength-shifter infusion, every ~0.05 increase in the ice's refractive index will increase IceCube's photon sensitivity by 100%, opening the possibility for the substantial, cost effective expansion of IceCube's reach.