DNP-NMR Probe Vacuum Window Optimization
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Solution Overview
Problem
The existing DNP-NMR probes face a reduction in microwave transmittance due to vacuum windows, leading to decreased DNP efficiency and NMR signal intensity, as the relaxation time of radicals is short, affecting the polarization transfer from electron spin to nuclear spin.
Innovation Solution
Optimizing the window thickness and window-to-window distance of vacuum windows in the DNP-NMR probe to enhance microwave transmittance, allowing for specific adjustments within defined ranges to maximize DNP efficiency and NMR signal intensity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If vacuum windows are provided in waveguides to enhance vacuum insulation, then vacuum insulation is improved, but microwave transmittance is reduced
Solution Approach 1:
The patent optimizes the thickness parameter of the vacuum window and the distance parameter between vacuum windows to achieve maximum microwave transmittance. By carefully selecting these parameters, the system maintains vacuum insulation while minimizing microwave attenuation, directly resolving the technical contradiction between vacuum insulation and microwave transmittance.
2Strength
If window thickness is increased to improve structural integrity, then strength is improved, but microwave transmittance is reduced
Solution Approach 1:
The patent determines an optimal window thickness parameter that balances structural strength requirements with microwave transmittance efficiency. This parameter optimization ensures the vacuum window maintains sufficient mechanical integrity while minimizing its attenuating effect on microwaves, resolving the contradiction between strength and transmittance.
3Reliability
If window-to-window distance is increased to improve vacuum insulation, then vacuum insulation is improved, but microwave transmittance is reduced
Solution Approach 1:
The patent optimizes the window-to-window distance parameter to achieve the best balance between vacuum insulation performance and microwave transmission efficiency. By carefully selecting this distance parameter, the system maintains effective vacuum insulation while minimizing the total attenuation caused by multiple windows, directly resolving the technical contradiction.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The optimization of window thickness and distance significantly increases microwave transmittance, thereby improving DNP efficiency and achieving higher NMR signal intensity by extending the relaxation time of radicals, allowing for effective polarization transfer.
Implementation Method 1
Microwaves propagating through the waveguide of the outer container are transmitted to the waveguide of the inner container through the two vacuum windows
Implementation Method 2
According to the present invention, high NMR signal intensity can be obtained by increasing the transmittance of micrawves passing through the vacuum windows
Data Source
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AI summary
Attenuation of microwaves is reduced or prevented when vacuum windows are provided in microwave waveguides of a DNP-NMR probe. A DNP-NMR probe (10) has an inner container (20) and an outer container (90). The inner container (20) has therein a sample tube (30) containing a sample to which radicals are added. The outer container (90) keeps a space between the outer container and the inner container (20) in the outer container in a vacuum state. The outer container (90) has an outer container waveguide (96) that has a vacuum window (98) at an inner end portion and guides microwaves. The inner container (20) has a vacuum window (28) facing the vacuum window (98) of the outer container waveguide (96) through vacuum, and guides microwaves transmitted from the outer container waveguide (96) to the sample. The window-to-window distance between the vacuum window (98) of the outer container (90) and the vacuum window (28) of the inner container (20) is adjusted by means of adjustment bolts (74).