A New High Parallel-Field Spectrometer at TRIUMF's $\beta$-NMR Facility

TL;DR

This paper introduces a new high-field $eta$-NMR spectrometer at TRIUMF enabling depth-resolved electromagnetic studies of materials like superconductors at higher magnetic fields than before.

Contribution

The paper details the design, implementation, and commissioning of a novel high-field $eta$-NMR spectrometer capable of reaching 200 mT fields parallel to samples, expanding research capabilities.

Findings

Successful construction and commissioning of the spectrometer.

Ability to perform depth-resolved $eta$-NMR at higher fields.

Potential applications in studying superconducting materials.

Abstract

A new high field spectrometer has been built to extend the capabilities of the $\beta$-detected nuclear magnetic resonance ($\beta$-NMR) facility at TRIUMF. This new beamline extension allows $\beta$-NMR spectroscopy to be performed with fields up to 200 mT parallel to a sample's surface (perpendicular to the ion beam), allowing depth-resolved studies of local electromagnetic fields with spin polarized probes at a much higher applied magnetic field than previously available in this configuration. The primary motivation and application is to allow studies of superconducting radio frequency (SRF) materials, close to the critical fields of Nb metal, which is extensively used to fabricate SRF cavities. The details of the design considerations and implementation of the ultra-high vacuum (UHV) system, ion optics, beam diagnostics are presented here. Commissioning of the beamline and spectrometer with radioactive ions are also reported here. Future capabilities and applications in other areas are also described.