Coaxial Coil Array for Homogeneous Magnetic Field Orientation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current devices for generating orientable and homogeneous magnetic fields face challenges in achieving the required amplitude and homogeneity, especially in applications like neutron diffraction and nuclear magnetic resonance, with limited angular access and complexity in rotating magnetic fields.
Innovation Solution
A device comprising multiple coaxial coils arranged in a circular pattern, with independent current supply systems, allows for the generation of a homogeneous magnetic field with axial access and equatorial opening, enabling the orientation of the field in three dimensions and rotation in a plane, while maintaining high homogeneity and reducing complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If three pairs of coaxial coils (split coils) are used to generate an orientable magnetic field with high homogeneity (better than 0.5% on a 10mm sphere), then the magnetic field homogeneity is improved, but the equatorial angular opening is very limited with no continuous opening
Solution Approach 1:
The device divides the coil system into multiple independent coaxial coil pairs (at least two pairs), each capable of being independently controlled. This segmentation allows different coil pairs to serve different functions: some optimized for homogeneity along specific axes, others providing angular access. The magnetic field is generated by coordinated operation of these segmented coil units, resolving the contradiction between homogeneity and angular opening.
Solution Approach 2:
Each coaxial coil pair is designed to serve multiple functions: generating magnetic field components for orientation control, maintaining homogeneity in the sample region, and enabling angular access for neutron beams. The universal design of the coil pairs allows the system to achieve both high homogeneity and continuous equatorial opening without requiring separate specialized systems.
2Adaptability or versatility
If a magnet is rotated to generate a rotating magnetic field for nuclear magnetic resonance, then the rotating field is achieved, but the device complexity increases with reliability and vibration problems
Solution Approach 1:
The patent replaces the mechanical rotation system with an electromagnetic field system. Instead of physically rotating a magnet, the invention uses multiple coaxial coil pairs with independently controllable currents to generate the rotating magnetic field effect. By adjusting the phase and amplitude of currents in different coil pairs, a rotating magnetic field is created without any mechanical moving parts, eliminating complexity, vibration, and reliability issues associated with mechanical rotation.
Solution Approach 2:
The system achieves dynamic rotating magnetic field generation through time-varying current control of the stationary coil pairs. The currents are dynamically adjusted in phase and magnitude to create the effect of a rotating field, allowing flexible and vibration-free rotation without mechanical inertia or friction.
3Ease of operation
If axial access of at least 100mm diameter is provided for sample introduction, then the ease of operation is improved, but the magnetic field homogeneity becomes difficult to maintain
Solution Approach 1:
The coil pairs are positioned and dimensioned to create a localized region of high magnetic field homogeneity (better than 0.5% on a 10mm sphere) while maintaining a large axial opening (at least 100mm diameter) for sample introduction. The local quality of the magnetic field is optimized in the sample region through careful coil geometry and current control, while the overall structure preserves axial accessibility.
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 solution provides a magnetic field with an amplitude of 1T and homogeneity better than 0.5% in a 10mm diameter sphere, with axial access and equatorial opening, suitable for various scientific applications, and reduces the complexity and reliability issues associated with prior art.
Implementation Method 1
using a plurality of coaxial coils, regularly arranged along a circle, to generate a homogeneous magnetic field oriented in a radial direction
Implementation Method 2
generate a homogeneous magnetic field oriented in a radial direction (perpendicular to the axial direction), and possibly also a axial magnetic field whose amplitude can be fixed independently of that of the radial magnetic field
Data Source
Figure 1~3B
Figure 4A~5B
Figure 6A~7
AI summary
The device has identical assemblies (EBn) comprising cylindrical coils (B1n, B2n) that are oriented along a direction and arranged symmetrically on a side of a XY-plane perpendicular to a Z-axis. The assemblies are arranged such that outlines of the assemblies are regularly spaced along a circle. A supply system supplies current to the coils, where the current is represented by an expression relating a nominal current, an azimuthal angle relative to a reference direction, an azimuthal angle of a magnetic field, a zenith angle of the field and an angle adjustable by a user.