Helmholtz Coil NMR Probe for Vacuum Discharge Prevention
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Solution Overview
Problem
Conventional NMR probes face challenges in preventing electric discharge during high-frequency oscillating field application to solid samples, leading to unreliable measurement results and noise interference, especially due to multipactor discharge in high-vacuum environments.
Innovation Solution
A magnetic resonance signal detection module with a low-frequency nuclide coil and a high-frequency nuclide coil configuration, where the high-frequency nuclide coil is embedded in a Helmholtz coil arrangement surrounding the low-frequency nuclide coil, reducing mutual inductance and capacitive coupling, and using a ribbon-like conductor shape to minimize the confronting area, thereby preventing electric discharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If high-frequency oscillating field is applied to solid samples in conventional NMR probes, then magnetic field irradiation efficiency is improved, but electric discharge occurs leading to unreliable measurement results and noise interference
Solution Approach 1:
The patent transitions from conventional planar coil structures to a three-dimensional Helmholtz coil configuration with orthogonal windings. This dimensional change creates a more uniform magnetic field distribution and reduces electric field concentration at specific points, thereby preventing electric discharge while maintaining high-frequency irradiation efficiency. The orthogonal arrangement of windings in three-dimensional space allows the magnetic field to be generated without the electric discharge problems associated with planar coil geometries.
Solution Approach 2:
The patent modifies the geometric parameters of the coil structure by using a Helmholtz configuration with specific radius and winding density. The radius R and number of windings n are optimized to achieve the desired magnetic field strength while maintaining parameters that prevent electric discharge. The specific parameter configuration of the Helmholtz coil (equal currents in orthogonal windings, specific spacing) changes the electromagnetic field distribution to eliminate multipactor discharge conditions.
2Device complexity
If conventional coil configuration is used in high-vacuum environment, then device complexity is reduced, but multipactor discharge occurs causing noise interference
Solution Approach 1:
The patent employs a three-dimensional Helmholtz coil structure with orthogonal windings instead of conventional planar coils. This dimensional transformation creates a magnetic field generation mechanism that does not produce the electric field conditions necessary for multipactor discharge in vacuum environments. The orthogonal arrangement distributes electric fields more uniformly, preventing the localized field enhancement that triggers multipactor discharge.
Solution Approach 2:
The patent converts the challenge of vacuum environment into an advantage by designing a coil structure where the magnetic field generation process itself prevents multipactor discharge. The Helmholtz configuration's inherent electromagnetic field distribution characteristics create conditions where high-frequency operation in vacuum does not lead to discharge, thereby eliminating noise interference while maintaining operational simplicity.
3Reliability
If high-frequency nuclide coil is embedded in Helmholtz coil arrangement, then electric discharge is prevented, but mutual inductance and capacitive coupling must be minimized
Solution Approach 1:
The patent optimizes the geometric parameters of the Helmholtz coil, specifically the radius R and winding density, to minimize mutual inductance between the high-frequency nuclide coil and the Helmholtz coil windings. The spacing and orientation parameters are carefully selected to reduce capacitive coupling while maintaining the electric discharge prevention benefits of the Helmholtz configuration. These parameter optimizations balance the competing requirements of discharge prevention and electromagnetic coupling minimization.
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
This configuration enhances magnetic field irradiation efficiency and NMR signal detection sensitivity while preventing electric discharge, allowing for reliable high-frequency irradiation without multipactor discharge, even in high-vacuum conditions.
Implementation Method 1
a low-frequency nuclide coil (LF coil) provided on an inner surface of a detection hole, and a high-frequency nuclide coil (HF coil) embedded in the coil mounting section in such a way as to surround the low-frequency nuclide coil
Implementation Method 2
a conductor of the low-frequency nuclide coil and a conductor of the Helmholtz coil have a ribbon-like shape, and a flatwise face of a ribbon forming the conductor of the low-frequency nuclide coil and an edgewise face of a ribbon forming the conductor of the Helmholtz coil face each other
Data Source
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AI summary
An insulator block (28) has a coil mounting section (126) including a through hole (130) serving as a detection hole into which a sample container can be inserted. An LF coil (86) is provided on an inner surface of the through hole (130). An HF primary resonator (88) is embedded in the coil mounting section (126) so as to surround the LF coil (86).