The new high field photoexcitation muon spectrometer at the ISIS pulsed neutron and muon source

TL;DR

This paper describes the upgrade of the HiFi muon spectrometer with a high power pulsed laser system, enabling light-pump muon experiments under high magnetic fields for advanced material studies.

Contribution

The paper introduces a novel laser system integration into the HiFi muon spectrometer, allowing controlled photoexcitation in high magnetic field conditions.

Findings

Demonstrated photoexcitation of samples using the new laser system

Enabled muon spin spectroscopy under high magnetic fields with light-pump techniques

Showcased potential applications through a demonstration experiment

Abstract

A high power pulsed laser system has been installed on the high magnetic field muon spectrometer (HiFi) at the ISIS pulsed neutron and muon source, situated at the STFC Rutherford Appleton Laboratory in the UK. The upgrade enables one to perform light-pump muon-probe experiments under a high magnetic field, which opens new applications of muon spin spectroscopy. In this report we give an overview of the principle of the HiFi Laser system, and describe the newly developed techniques and devices that enable precisely controlled photoexcitation of samples in the muon instrument. A demonstration experiment illustrates the potential of this unique combination of the photoexcited system and avoided level crossing technique.