Jeol Ltd.

Varian, Inc.

Agilent Technologies, Inc.

Joel Ltd.

Albert Zens

James Finnigan

Jason William Cosman

Peter Nakatani

In various embodiments of the invention, a cooled nuclear magnetic resonance (NMR) probe can utilize a sliding band capacitor which can be moved relative to a parent coil inner conductance tapered skirt to adjust the frequency of the parent coil to allow the parent coil to detect the resonance of at least two nuclei without requiring leads between the parent coil and a lock coil. In this manner a cooled NMR probe can be provided without the disadvantages of prior art cooled NMR probes. In an embodiment of the invention, the sliding band capacitor comprises a diamagnetic insulator with a first volume magnetic susceptibility, at least one paramagnetic metal with a second volume magnetic susceptibility and at least one diamagnetic metal with a third volume magnetic susceptibility, where the sum of the first volume magnetic susceptibility, the second volume magnetic susceptibility and the third volume magnetic susceptibility is approximately zero.

Sliding band capacitor inductive coupling in a low temperature nuclear magnetic resonance probe and methods of use

In various embodiments of the invention, a solid sample magic angle spinning nuclear magnetic resonance (NMR) probe can utilize an appropriate inductance parent coil with a fixed capacitor and introducing an idler coil with a variable capacitor which can inductively couple to the parent coil by adjusting the variable capacitance of the idler coil. By coupling the idler coil to the parent coil in this manner a double resonance circuit can be provided without the disadvantages of prior art coils. In an alternative embodiment of the invention, a solid sample magic angle spinning nuclear magnetic resonance probe can utilize an appropriate inductance parent coil with a fixed capacitor, introducing an idler coil with a variable capacitor in a first region and two variable inductor coupling coils and two coupling coils in a second region, where the two variable inductors are connected to the parent coil to reduce the number of coils in the sample region of the NMR probe, where variable inductors can inductively couple to the parent coil by adjusting one or both the capacitance of the variable capacitor of the idler coil and/or adjusting the variable inductors to observe a tuned condition between the parent coil and the idler coil.

Solid sample magnetic coupling high resolution nuclear magnetic resolution probe and method of use

In a first aspect, the present invention relates to a Nuclear Magnetic Resonance (NMR) probe and method of use of a NMR probe for matching a resonant mode in a circuit to a required impedance (e.g., Z=50 Ohm) using a variable inductor which allows matching of the resonant mode in the circuit within a broad frequency range. In an additional aspect, the NMR probe and the method of use of a NMR probe allows matching of a resonant mode in a circuit to a required impedance (e.g., Z=50 Ohm) using a variable inductor without requiring the coupling constant K to be varied over a broad frequency range. In a further aspect, the invention relates to a method to detect a Nuclear NMR mode of a nuclei including the steps of introducing a sample into a NMR probe comprising a primary circuit and a secondary circuit, where the primary circuit comprises a sample coil, a first variable capacitor and a RF pulse generator, where the secondary circuit comprises a coupling loop, a variable inductor and an impedance port, introducing the NMR probe into a magnetic field, exciting the sample with the RF pulse generator, inductively coupling the coupling loop to the sample coil, adjusting the first variable capacitor and the variable inductor to match the impedance to the required impedance of the impedance port and detecting a NMR mode of a nuclei of the sample.

Broad band inductive matching of a nuclear magnetic resonance circuit using inductive coupling

In an embodiment of the invention inductive coupling of an idler coil to a parent coil is used to provide a double resonance circuit without the disadvantages of capacitive coupling to the parent coil. In an embodiment of the invention, an inductive coupling coil can be used to achieve a double-tuned circuit. In an embodiment of the invention, a circuit uses inductive coupling to achieve a double resonance circuit forH,F, andC experiments where one of the three nuclei are observed and the other two are decoupled. In an embodiment of the invention a pivot or a shunt can be used to couple and decouple the idler coil and the parent coil.

Magnetic coupling high resolution nuclear magnetic resolution probe and method of use

In various embodiments of the invention, inductive coupling can be to a secondary coil rather than a primary coil in order to optimize the topology of the NMR probe. In addition, by coupling to a secondary coil using a detection coil located below the lower insulator the RF homogeneity and signal to noise can be improved together with the NMR probe topology. By effecting inductive coupling to an inductor in a multiple resonance circuit, rather than to the sample inductor parameters associated with the NMR, probe construction can be arranged to increase RF homogeneity and signal to noise, while reducing space utilization constraints. In various embodiments of the invention, the primary mode in a secondary coil can be split into two modes with a resonator with inductive coupling to the secondary coil.

Inductive coupling in multiple resonance circuits in a nuclear magnetic resonance probe and methods of use

An NMR probe comprising an RF resonatorserves in a first mode for conventional sensitivity optimized studies of abundant samples at frequency &#x3c9;, and in a second mode for independent sensitivity optimized studies of micro sample quantities at frequency &#x3c9;through use of a removably insertable self-resonant micro-coilwithin the RF resonatorand 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-coilto induce self-resonance of the micro-coilat &#x3c9;.

Dual-use NMR probe

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.

Low loss NMR sample holder

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.

Multi-functional NMR probe

An NMR resonant structure is formed of axial conductors (, and) and end members (), supporting said conductors to form a coil structure () 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 capacitancefor the resonant structure.

Axially constrained RF probe coil

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.

Growing community of inventors

Peabody, MA, United States of America

Albert Zens