Proposal for a new spectrometer at ESS: Njord and Remora

TL;DR

This paper proposes Njord and Remora, two linked neutron spectrometers at ESS, designed to enhance flux and focus for studying small or weak signals in challenging samples.

Contribution

Introduction of Njord and Remora as a paired instrument concept to improve neutron flux and measurement capabilities at ESS.

Findings

Design focus on high brightness and focused beam for small samples

Complementary spectral capabilities with Remora spectrometer

Addressing current limitations in neutron scattering experiments

Abstract

Many of the most interesting scientific subjects are also the hardest to study with neutrons. Metal-organic frameworks, organic superconductors, quantum magnets, pressure-tuned materials, are systems where the relevant signals are weak, the samples are tiny, or the experiments need extreme sample environments such as pressure cells and high-field cryomagnets. Existing instruments often run into practical limits before the science is exhausted. For some questions the samples are simply too small; for others, the signal is buried in background or the required measurement time becomes prohibitive. This is both a scientific opportunity and a challenge for the European neutron scattering community. We present Njord and Remora as a paired instrument concept for the European Spallation Source (ESS). The proposal focuses on two linked problems: important science cases are being limited by neutron flux and sample geometry, and the community also needs more beamtime. Njord addresses the first by pushing the available brightness into a tightly focused beam, while Remora uses the remaining spectral window to add a complementary spectrometer on the same beamport.