HTS Shim Device with Segmented Circulating Current Paths
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Solution Overview
Problem
Existing high-temperature superconductor (HTS) shim devices for magnet arrangements face limitations in generating complex field distributions and achieving even-order field gradients without odd-order 'impurities', due to restricted design options and increased heat generation during charging, which affects cryostat efficiency and field homogeneity.
Innovation Solution
A shim device with a conductor trace that forms three circulating current paths, including one path around both openings, allowing for more complex designs and even-order field gradients, utilizing HTS material and a dual-switch configuration for efficient inductive charging and reduced heat generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If direct connection charging method is used for HTS shim coil, then charging is simple, but large power supply lines conduct heat into cryostat and generate Joule heat
Solution Approach 1:
The patent introduces a charging coil as an intermediary component that inductively couples to the shim coil through a common magnetic flux. This mediator enables energy transfer without direct electrical connection, eliminating the need for large power supply lines that conduct heat into the cryostat and avoiding Joule heat generation in the leads.
Solution Approach 2:
The patent replaces the mechanical/electrical direct connection charging system with an electromagnetic inductive charging system. Instead of using physical power supply lines that conduct heat, the system uses magnetic field coupling between the charging coil and shim coil to transfer energy, substituting a thermal-mechanical process with an electromagnetic process.
2Device complexity
If single circulating current path is used, then design is simple, but complex field distributions and even-order field gradients cannot be generated
Solution Approach 1:
The patent segments the single circulating current path into multiple independent paths (first, second, and third circulating current paths) that can be independently controlled. Each path can be selectively interrupted by shim switches, enabling independent current control in each path to generate complex field distributions and even-order field gradients that cannot be achieved with a single path.
Solution Approach 2:
The patent introduces dynamic control capability through shim switches that can independently interrupt different circulating current paths. This allows the system to dynamically adjust which current paths are active and in what directions, providing versatility in generating various field distributions while maintaining a relatively simple physical conductor track structure.
3Power
If larger electrical currents are used for persistent shim coils, then field strength is achieved, but heat generation during charging increases
Solution Approach 1:
The patent replaces direct electrical connection with inductive coupling to transfer large currents to the persistent shim coil without the large power supply lines that generate Joule heat. The inductive charging method allows high current transfer through magnetic field coupling while keeping the charging leads small and minimizing resistive losses.
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
Enables the generation of complex field distributions with greater design freedom, reducing heat-related issues during charging and maintaining field homogeneity, while minimizing cryogenic resource consumption.
Implementation Method 1
at least one shim conductor track (C) comprising HTS (=high-temperature superconductor material)
Implementation Method 2
A magnet arrangement and a method for charging a shim device with a charging coil (P), wherein an inductive current change can be brought about in the HTS shim conductor track (C)
Data Source
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AI summary
The shim device (D) according to the invention for use in a magnet arrangement, wherein the shim device (D) comprises at least one HTS (= high-temperature superconducting material) shim conductor track (C) and a first shim switch (Sw1), wherein the shim conductor track (C) lies on a surface curved about an axis (z) and the first shim switch (Sw1) is arranged in a first conductor track section (S1) of the shim conductor track (C) for temporarily interrupting the superconducting state of the first conductor track section (S1), is characterized in that the shim conductor track (C) extends around at least a first opening (O1) and a second opening (O2), such that the shim conductor track (C) comprises a first circulating current path (L1), a second circulating current path (L2) and a third circulating current path (L3), wherein two of the three circulating current paths (L1, L2, L3) only surround one of the openings (O1, O2) each and one of the circumferential current paths (L1, L2,L3) surrounds both openings (O1, O2), and the first conductor section (S1), in which the first shim switch (Sw1) is located, is part of only the first circulating current path (L1) and the second circulating current path (L2). This allows a persistent HTS shim for field homogenization to be implemented, enabling both a complex field distribution and great freedom in shim design.