Abstract: An NMR probe comprising an RF resonator 48 serves in a first mode for conventional sensitivity optimized studies of abundant samples at frequency ?0, and in a second mode for independent sensitivity optimized studies of micro sample quantities at frequency ?0 through use of a removably insertable self-resonant micro-coil 50 within the RF resonator 48 and closely surrounding a micro sample, that is preferably independently removably insertable within the micro-coil. The NMR probe exhibits an enhanced tuning range to resonate in its first mode and in the second mode to inductively couple to the self-resonant micro-coil 50 to induce self-resonance of the micro-coil 50 at ?0.

Abstract: An NMR probe comprising an RF resonator 48 serves in a first mode for conventional sensitivity optimized studies of abundant samples at frequency ?0, and in a second mode for independent sensitivity optimized studies of micro sample quantities at frequency ?0 through use of a removably insertable self-resonant micro-coil 50 within the RF resonator 48 and closely surrounding a micro sample, that is preferably independently removably insertable within the micro-coil. The NMR probe exhibits an enhanced tuning range to resonate in its first mode and in the second mode to inductively couple to the self-resonant micro-coil 50 to induce self-resonance of the micro-coil 50 at ?0.

Abstract: An elongate sample volume matching an elongate region of uniform RF magnetic field established by a saddle coil, is approximated by at least one pair of cylindrical sample tubes in parallel orientation with the geometric axis of the saddle coil. The displacement of the two cylindrical tubes defines a direction transverse to the tube axes and this transverse direction is aligned parallel with the RF magnetic field of the saddle coil.

Abstract: A single RF port, multiply-resonant circuit comprises coupled resonant sub-circuits coupled through an adjustable reactive element exhibiting a dynamic range that includes a value of the reactive component of sufficient magnitude to produce an impedance producing substantial mutual isolation of the sub-circuits.

Abstract: An NMR resonant structure is formed of axial conductors (54a, 54b, 54c, and 54d) and end members (50,51), supporting said conductors to form a coil structure (8) of desired electrical topology wherein the end members combine the function of RF interconnects between selected axial conductors (inductors) with an axial constraint on RF field prevailing outside the axial bounds of the end members, and if so desired, comprise a selected capacitance 61 for the resonant structure.

Abstract: A time multiplex arrangement for presenting multiple samples to a single channel of NMR excitation/data acquisition includes means for rapid exchange of physical position between plural samples or sample portions from the measurement volume of the NMR instrument while said samples remain in a substantially the same homogeneous magnetic field. While a delay is imposed upon time evolution or relaxation of an NMR excited sample outside the sensitive volume of an RF resonator, another sample is actively excited within said RF resonator whereby the steps of NMR measurement are overlapped between at least two samples.

Abstract: An NMR probe comprises a pair of capacitively coupled inductive members forming a first circuit resonant to a relatively high rf signal and also forming a portion of a second tuned circuit resonant at a relatively low rf signal, the entire circuit balanced to define a virtual ground in said circuit portions and relative isolation of low and high frequency sources achieved with transmission line elements.

Abstract: The tuned LC circuit of an NMR probe includes a coil center tapped to ground through a capacitance selected to constrain parasitic resonances to a frequency region below decoupler frequencies employed in the probe.

Abstract: Multiple concurrent sample processing in a single spectrometer is accomplished for the respective situation of (a) samples of strongly dissimilar character and (b) samples of similar character. For the class (a) samples yielding non-superimposed line spectra are axially separated by susceptability matched delimiters in a sample tube and analyzed in a conventional spectrometer. For the class (b), resonance response from axially separated samples induce signals in respective observe coils similarly spaced along the axis of said sample tube. Plural samples disposed in non-colinear parallel alignment are also treated in this manner.

Abstract: It is desired to promote magnetic homogeneity of materials, including structural elements, present in the sensitive volume of a gyromagnetic analysis apparatus. Where the sample is rotated along an axis transverse to the field the requirement reduces to establishing axial homogeneity. Plugs which match the solvent magnetic susceptibility are employed to constrain a sample within the central region of an RF probe coil thereby appearing relatively invisible in the magnetic sense to the instrument. The susceptibility of materials can be tailored to achieve a desired value to suppress magnetic perturbation without introducing extraneous signals.

Abstract: An RF probe for a gyromagnetic resonance spectrometer includes a coil cage for supporting the probe coil preferably within the cage formed of a number of rod-like members displaced parallel to the coil axis and spaced apart from the axis at a constant distance. Access to the coil through an axial continuous slot 46 or equivalent eliminates axial discontinuity in susceptibility due to discrete holes in the coil form.

Abstract: A saddle coil for operation in the probe of an NMR spectrometer is formed from coil portions of opposite helicities disposed on a flexible insulating material, the outer windings of said portions connected by a linking conductor disposed on said insulating medium, which medium is then deformed to form a cylindrical body.