A double-tuned probe for metabolic NMR studies

A double-tuned single coil probe for high field metabolic NMR studies has been designed and tested. The resonant coil is a single-turn of copper foil wound on a quartz cylinder. It is fed by a short length of parallel strip line made of the same material; the feeder is also used as a tuning capacitance. Electrical parameters (quality factors, efficiencies at proton and carbon frequencies) and magnetic resonance data (90 degrees pulse lengths, minimum decoupler power) for lossy samples have been measured. The probe allows for the optimal use of the limited high homogeneity region of a vertical magnet. It shows good sensitivity and efficient decoupling.