초록 ▼

An NMR measuring system with an NMR probehead has at least one cooling device (5a, b) generating a vibration spectrum of individual selective frequencies. The cooling device is mechanically connected to a vibration absorber (9a, 9b) having an oscillating mass element (27), whose resonance frequency

An NMR measuring system with an NMR probehead has at least one cooling device (5a, b) generating a vibration spectrum of individual selective frequencies. The cooling device is mechanically connected to a vibration absorber (9a, 9b) having an oscillating mass element (27), whose resonance frequency is adjusted to the vibration frequency of the cooling device and/or to one of its harmonics. The cooling device has a cooling head which is thermally connected to an NMR resonator of the probehead via a flexible mechanical element. A vacuum housing of the probehead is designed in two parts which are mechanically connected via at least one damping element (30a-d). The lower part and the upper part of the vacuum housing are additionally mechanically flexibly connected to each other in a vacuum-tight fashion via a corrugated bellows (8a, 8b). The system minimizes sidebands in NMR spectra.

대표청구항 ▼

1. An NMR (nuclear magnetic resonance) measuring system, for measuring a test sample, the measuring system comprising: an NMR magnet system;a vacuum housing disposed within said NMR magnet system, said vacuum housing having a lower part and an upper part;an NMR probehead disposed within said vacuum

1. An NMR (nuclear magnetic resonance) measuring system, for measuring a test sample, the measuring system comprising: an NMR magnet system;a vacuum housing disposed within said NMR magnet system, said vacuum housing having a lower part and an upper part;an NMR probehead disposed within said vacuum housing;an NMR resonator disposed within said NMR probehead to surround the test sample;a cooling device having a cooling head, said cooling device generating a vibration spectrum that only consists of individual selective frequencies;a heat conducting carrier element in thermal connection with said NMR resonator;a heat conducting connecting element, disposed between and in thermal connection with said heat conducting carrier element and said cooling head, wherein said cooling device, said heat conducting carrier element and said heat conducting connecting element are disposed, structured and dimensioned to cool said NMR resonator to cryogenic temperatures;a vibration absorber mechanically connected to said cooling device, said vibration absorber having at least one oscillating mass element, wherein said at least one oscillating mass element has a resonance frequency which is adjusted to a vibration frequency of said cooling device or to a harmonic thereof;a mechanically flexible connecting element having good thermal conducting properties, said mechanically flexible connecting element disposed between and connecting said cooling head to said heat conducting connecting element;at least one damping element disposed between and connecting said upper and said lower parts of said housing;a diaphragm or corrugated bellows disposed between and connecting said lower and said upper parts of said housing in a vacuum-tight and mechanically flexible manner;heat insulating mountings disposed between and fixing said connecting element to said housing; anda shim system to which said probehead is mechanically fixed. 2. The NMR measuring system of claim 1, further comprising a further vacuum housing having a lower part and an upper part, a preamplifier disposed within said further vacuum housing, a further cooling device having a cooling head, said further cooling device generating a vibration spectrum that only consists of individual selective frequencies, a further vibration absorber, mechanically connected to said further cooling device, said further vibration absorber having at least one further oscillating mass element, said at least one further oscillating mass element having a resonance frequency which is adjusted to a vibration frequency of said further cooling device or to a harmonic thereof, a further mechanically flexible connecting element having good thermal conducting properties, said further mechanically flexible connecting element disposed between and connecting said cooling head of said further cooling device to said preamplifier, at least one further damping element disposed between and connecting said upper and said lower parts of said further vacuum housing, a further diaphragm or corrugated bellows disposed between and connecting said lower and said upper parts of said further housing in a vacuum-tight and mechanically flexible manner and further heat insulating mountings disposed between and fixing said preamplifier to said further housing. 3. The NMR measuring system of claim 2, wherein said further cooling device is a FPSC (Free-Piston Stirling Cooler). 4. The NMR measuring system of claim 2, wherein at least three damping elements are arranged between said lower part and said upper part of said further vacuum housing of said preamplifier. 5. The NMR measuring system of claim 1, wherein said cooling device is a FPSC (Free-Piston Stirling Cooler). 6. The NMR measuring system of claim 1, wherein said mechanically flexible connecting element comprises a wire connector. 7. The NMR measuring system of claim 1, wherein at least three damping elements are arranged between said lower part and said upper part of said vacuum housing of said probehead. 8. The NMR measuring system of claim 7, wherein said damping elements are symmetrically arranged around a longitudinal axis of said probehead in a plane perpendicular to said longitudinal axis. 9. The NMR measuring system of claim 1, wherein said cooling device is mechanically connected to a laboratory floor via at least three further damping elements. 10. The NMR measuring system of claim 1, wherein said connecting element comprises copper. 11. The NMR measuring system of claim 1, wherein said carrier element comprises copper or sapphire. 12. The NMR measuring system of claim 1, wherein said NMR resonator comprises a high-temperature superconductor (HTS) material. 13. The NMR measuring system of claim 1, wherein said vibration absorber is an active vibration absorber which contains a linear motor interacting for movement of said mass element and being part of a closed control loop, said linear motor being controlled by a digital control unit that is also arranged in said control loop, wherein mechanical vibrations of said cooling device and of said active vibration absorber at least largely mutually compensate each other. 14. The NMR measuring system of claim 13, wherein said control unit receives an error signal from an acceleration sensor via an analog-digital converter (ADC) and also receives a reference signal from an inductive sensor via an ADC, wherein an output of said control unit is connected to said linear motor via a digital-analog converter (DAC) and an amplifier unit. 15. The NMR measuring system of claim 13, wherein said control unit contains an adaptive filter, an output signal of which is also an output signal of said control unit.