Abstract: A nuclear magnetic resonance (NMR) probe circuit is used with a sample coil tuned to a primary frequency f1. The circuit is arranged to have a plurality of points of electric field minima at the f1 frequency. One or more additional frequencies may be coupled to the circuit at these points, without interaction with f1. The probe circuit also uses an impedance coupled between two of the minima points that affects the frequency response at the additional frequency or frequencies, without affecting the frequency response at f1. The impedance may be made adjustable to allow tuning of the relative frequency resonances.

Abstract: An NMR buffer is particularly useful for biomolecules that require a certain amount of salt in the buffer solution. A primary buffer component and a titrating component are selected based on low ion mobility. These selections allow for a lower conductivity buffer without reducing the salt content. As such, a higher sensitivity experiment results.

Abstract: Improved superconducting coils for a nuclear magnetic resonance probe use capacitive elements that are located in regions further from an active sample volume than magnetic field generating elements to which they are electrically connected. The sample volume is a substantially oblong shape, and the magnetic field generating elements run substantially parallel to the major axis of the shape, while the capacitor elements run perpendicular to the major axis. Gaps between the capacitor elements, and the width of the elements themselves, may increase toward the outside of the coil to minimize electrical discharge. The variation may be according to a monotonic, possibly linear, function. Discharge may also be minimized by using a dielectric cover that, together with a coil substrate, encloses the coil.

Abstract: Improved superconducting coils for a nuclear magnetic resonance probe use capacitive elements that are located in regions further from an active sample volume than magnetic field generating elements to which they are electrically connected. The sample volume is a substantially oblong shape, and the magnetic field generating elements run substantially parallel to the major axis of the shape, while the capacitor elements run perpendicular to the major axis. The magnetic field generating elements and the capacitor elements may vary in length relative to their distance from a center of the oblong shape. The total number of capacitors formed by the loops may vary from one embodiment to another, typically depending on the necessary resonant frequency. A coil may use sub-coils, each of which incorporates a plurality of the magnetic field generating elements and interdigital capacitor elements, the capacitor elements preferably being located to both sides of the oblong shape.

Abstract: A double tuned probe for employment in NMR apparatus includes a first resonant circuit of normal phase conductor coupled to the sample and also in communication with a second circuit containing a component in a superconductive phase. Communication between the two circuits supports two RF channels which may be exhibit relative sensitivities in proportion to their relative Q values.