Progress Towards a Higher Sensitivity ¹³C-Optimized 1.5 mm HTS NMR Probe.

Area of Science:

• Magnetic Resonance Spectroscopy
• Superconducting Materials Science
• Analytical Chemistry Instrumentation

Background:

• High sensitivity Nuclear Magnetic Resonance (NMR) probes are crucial for small-sample analysis.
• Thin-film high temperature superconducting (HTS) resonators offer superior sensitivity in NMR.
• Existing HTS NMR probes require optimization for specific nuclei like Carbon-13 (13C).

Purpose of the Study:

• To develop and characterize an improved 1.5 mm HTS NMR probe for 14.1 T operation.
• To optimize the probe for enhanced 13C detection sensitivity.
• To investigate the impact of superconducting resonator and normal metal tuning loop interactions on probe performance.

Main Methods:

• Design and construction of a 1.5 mm probe utilizing HTS resonators for 13C, 1H, and 2H.
• Testing of a novel 13C resonator engineered for increased sensitivity.
• Evaluation of coil resonance frequency and probe sensitivity considering resonator and tuning loop interactions.

Main Results:

• The improved HTS NMR probe operates at 14.1 T with a total sample volume of 35 μL (20 μL active).
• A recently introduced 13C resonator design achieved a 13C quality factor of 6000 at zero field.
• This represents a significant increase in 13C detection sensitivity compared to previous all-HTS probes.

Conclusions:

• The developed 1.5 mm HTS NMR probe demonstrates significantly enhanced 13C detection sensitivity.
• The novel 13C resonator design is key to achieving higher quality factors and improved performance.
• Coil design considerations and build-out procedures are critical for optimizing HTS NMR probe sensitivity.