Hybrid Toroidal Field Coil for Fusion Reactors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge in compact spherical tokamaks is the limited space in the central column, which prohibits adequate shielding for the central windings, leading to high energy dissipation and vulnerability to neutron damage, necessitating a trade-off between shielding thickness and superconductor size for efficient magnetic field generation.
Innovation Solution
A hybrid toroidal field coil structure is proposed, comprising a low temperature superconductor (LTS) inner layer, a high temperature superconductor (HTS) central layer, and a non-superconducting conductive outer layer, with vacuum gaps for insulation, to achieve higher magnetic fields and reduce neutron damage while minimizing shielding thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thicker shielding is added to protect central windings from neutron damage, then reliability improves, but device complexity and space requirements worsen
Solution Approach 1:
A non-superconducting conductive layer is introduced as an intermediary component between the superconducting layers and the neutron environment. This intermediate layer absorbs neutron damage preferentially, protecting the superconducting materials while allowing the system to maintain compact dimensions without requiring excessive shielding thickness.
Solution Approach 2:
The patent employs a nested multi-layer structure where superconducting layers (LTS and HTS) are positioned inside a protective non-superconducting conductive layer. This nested configuration allows the shielding function to be integrated within the magnet structure itself, reducing overall device complexity while maintaining protection from neutron damage.
2Force
If larger superconductor size is used to generate stronger magnetic fields, then magnetic field strength improves, but space requirements and energy dissipation worsen
Solution Approach 1:
The patent combines different superconducting materials (LTS and HTS) with distinct properties in a hybrid configuration. The HTS layer operates at higher temperatures and can carry higher currents, while the LTS layer provides stability. This composite approach generates stronger magnetic fields within the limited central column space without increasing overall volume or energy dissipation.
Solution Approach 2:
The patent changes the operating temperature parameter by introducing HTS materials that operate at higher temperatures than traditional LTS. This parameter change allows for more efficient current carrying capacity and stronger magnetic field generation within the same volume, reducing the space requirements for achieving the desired magnetic field strength.
3Reliability
If more shielding is added to protect from neutron damage, then reliability improves, but energy dissipation worsens
Solution Approach 1:
The non-superconducting conductive layer serves as an intermediary that preferentially absorbs neutron damage through its higher neutron cross-section. This protects the superconducting layers from degradation while minimizing energy dissipation, as the intermediate layer can be optimized for neutron absorption without compromising the superconducting performance and efficiency.
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 allows for a stronger magnetic field with reduced shielding, enhancing the efficiency and stability of the spherical tokamak reactor by shielding superconductors from neutron damage and optimizing cooling, thus maintaining high magnetic field strength with lower current and reduced energy dissipation.
Implementation Method 1
a low temperature superconductor, LTS, layer (21) formed from LTS; a high temperature superconductor, HTS, layer (22) formed from HTS
Implementation Method 2
toroidal field coil for generating a toroidal magnetic field in a nuclear fusion reactor
Implementation Method 3
an outer layer of non-superconducting material... shielding the superconductor from neutron damage
Implementation Method 4
vacuum gaps for insulation, to achieve higher magnetic fields and reduce neutron damage while minimizing shielding thickness
Data Source
AI summary
A toroidal field coil for generating a toroidal magnetic field in a nuclear fusion reactor comprising a toroidal plasma chamber having a central column. The toroidal field coil comprises a portion passing through the central column. The portion passing through the central chamber comprises: ●a low temperature superconductor, LTS, layer (21) formed from LTS; ●a high temperature superconductor, HTS, layer (22) formed from HTS and located radially outward of the LTS layer. ●a non-superconducting conductive layer (23) formed from electrically conducting, non-superconducting material and located radially outward of the HTS and LTS layers.