NUCLEAR-MAGNETIC-RESONANCE PROBE FOR LOW-LEVEL HYDROGEN DETECTION

The design for a nuclear magnetic resonance (NMR) probe capable of detecting hydrogen signals at levels of < 5 x 10(16) H/sample is presented. In order to reduce background signals, the design eliminates polymeric materials from the probe head area and allows for a dry nitrogen purge during experimental runs to avoid signals due to ambient moisture. In addition, a metal cleaning process is employed that removes H-1 NMR detectable contaminants from copper components. Use of this NMR probe for thin solid films and other low hydrogen content materials is demonstrated. The probe holds these samples without a NMR sample tube, further eliminating background hydrogen signals. In addition, a calibration curve for low hydrogen content standards demonstrates that NMR signal response is indeed linear at low hydrogen concentrations, leading to accurate quantification of hydrogen.