Tokamak Central Column Cooling for Uniform HTS Tape Current

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing central columns for tokamak plasma chambers using high temperature superconductor (HTS) assemblies face challenges in uniform current distribution due to differences in critical current among HTS tapes, which are influenced by magnetic field strength and angle, leading to inefficient electrical current transport and increased nuclear heating.

Innovation Solution

A cooling mechanism is implemented to preferentially cool HTS assemblies, compensating for differences in critical current by generating a temperature gradient that matches the magnetic field gradient, ensuring more even current distribution and reducing nuclear heating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If HTS assemblies are used in the central column, then the critical current capacity is improved, but the uniformity of current distribution deteriorates due to differences in critical current among HTS tapes

Engineering Contradiction:

Improvecritical current capacityVSAvoiduniformity of current distribution

Core Design Contradiction:

PowerVSStability of the object's composition

Solution Approach 1:

The patent implements different cooling temperatures for different radial positions of HTS assemblies. The cooling mechanism provides localized temperature control where inner HTS assemblies (exposed to higher magnetic fields) are cooled to lower temperatures than outer assemblies, creating a radial temperature gradient that compensates for the magnetic field gradient and achieves uniform current distribution

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the temperature parameter radially across the HTS assemblies to compensate for magnetic field variations. By adjusting the operating temperature of each HTS assembly based on its radial position, the critical current of each assembly is optimized to achieve uniform current distribution despite differences in local magnetic field strength

Inventive Principle:

Principle #35Parameter changes

2Temperature

If uniform cooling is applied to all HTS assemblies, then the thermal stability is improved, but the current distribution uniformity deteriorates due to magnetic field gradients

Engineering Contradiction:

Improvethermal stabilityVSAvoidcurrent distribution uniformity

Core Design Contradiction:

TemperatureVSStability of the object's composition

Solution Approach 1:

The cooling mechanism is designed to provide non-uniform, position-dependent cooling to different HTS assemblies. The cooling temperature is locally optimized for each radial position, with inner assemblies receiving stronger cooling than outer assemblies, thereby achieving both thermal stability and current distribution uniformity simultaneously

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The cooling mechanism dynamically adjusts the temperature distribution across the HTS assemblies based on their radial positions and local magnetic field conditions. This dynamic temperature control allows the system to maintain optimal operating conditions for each assembly, compensating for magnetic field gradients and achieving uniform current distribution

Inventive Principle:

Principle #15Dynamics

3Adaptability or versatility

If HTS tapes with different critical currents are used, then the adaptability to magnetic field variations is improved, but the current transport efficiency deteriorates

Engineering Contradiction:

Improveadaptability to magnetic field variationsVSAvoidcurrent transport efficiency

Core Design Contradiction:

Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent changes the temperature parameter for each HTS assembly based on its radial position to optimize current transport efficiency. By adjusting the operating temperature, the critical current of each assembly is tuned to match the local magnetic field conditions, ensuring that all assemblies operate at optimal efficiency despite experiencing different magnetic field strengths

Inventive Principle:

Principle #35Parameter changes

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 approach results in a more uniform distribution of electrical current among HTS tapes, increasing current density and reducing nuclear heating, while maintaining mechanical integrity and thermal stability of the central column.

Implementation Method 1

Methodology Applied

Scientific EffectTemperature gradient: Temperature Gradient

Implementation Method 2

The central column comprises first and second high temperature superconductor, HTS, assemblies comprising a respective one or more HTS tapes for conducting electrical current parallel to an axis of the central column

Methodology Applied

Scientific EffectSuperconductivity: Superconductivity

Data Source

PatentUS20240371533A1Central column for a toroidal field coil of a tokamak plasma chamber

Publication Date: 2024.11.07 TOKAMAK ENERGY

AI summary

A toroidal field coil for a tokamak plasma chamber having a central column. The toroidal field coil comprises first and second high temperature superconductor. HITS, assemblies comprising a respective one or more HITS tapes for conducting electrical current parallel to an axis of the central column. Each of the HITS tapes comprises HITS material having an associated critical current that is dependent on a magnetic field at the HITS tape when the central column is in use. The central column further comprises a cooling mechanism configured to preferentially cool the first HITS assembly relative to the second HTS assembly to reduce or eliminate a difference in the critical current of the or each HITS tape of the first HITS assembly relative to the critical current of the or each HITS tape of the second HITS assembly.