| 研究課題/領域番号 |
20K04409
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| 研究機関 | 東北大学 |
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研究代表者 |
BADEL ARNAUD 東北大学, 金属材料研究所, 准教授 (00836017)
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| 研究分担者 |
淡路 智 東北大学, 金属材料研究所, 教授 (10222770)
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| 研究期間 (年度) |
2020-04-01 – 2022-03-31
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| キーワード | HTS / High Field magnets / Electromagnetic model |
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| 研究実績の概要 |
High temperature superconductors and especially REBCO Coated Conductors can enable a breakthrough in terms of performance for all magnet applications. However REBCO conductors can only be produced as several-mm wide tapes, in which the current distribution is inhomogeneous and changes with time. This affects negatively the field quality and stability. The aim of this project is to study how the current distributes in the conductor of practical REBCO magnets by means of modelling, and how this affect the magnet behaviour, then find ways to control it to enable reliable operation of these magnets.
During this first year, we focused our work on the development of the numerical model, and its experimental validation. Through the collaboration with an ongoing project at HFLSM, the modelling results were compared successfully with experimental data obtained on small scale test coils, both in terms of coil voltage and in terms of field dynamic.
Experimental confirmation was also obtained of the calculation of the exact coil inductance and its variations. This is a necessary step toward actively compensating the field error without the need for field measurement,the target of this project.
The restrictions due to the pandemic lead to a shortage of specific high performance processors. This prevented buying a simulation computer in the first fiscal year. As the size of the models so far was manageable on existing workstation this did not slow the project significantly.
This procurement will be concluded soon, which will make it possible to study bigger magnets in the coming year.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
Form the scientific point of view the progress of the project is fully satisfying.
An unforeseen event was the difficulty to procure a more powerful workstation (due to shortage as mentioned in the progress report) , so that the project budget planned for the first fiscal year, which was mostly for that purpose, is not used yet.
This equipment was not critical so far but it will be in the future for studying practical full sized magnets. Things have progressed so the workstation will be soon available, so there is no sources of concern for the future of the project.
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| 今後の研究の推進方策 |
The project will proceed as described in the proposal. The second year will be largely dedicated to expanding the model to large solenoidal coils with several thousands of turns.
More in details, the experimental validation for the modelling of such full scale coils can be made first on the results obtained by colleagues in Grenoble, who a currently testing increasingly big sets of REBCO coil pancakes (6 so far and 10 in the coming month). The interest of this test case is that the conductor is simple: it is a single REBCO tape.
In parallel with that, active current control to stabilize the field will be developed on small scale, first with real time field monitoring, then using the modelling results as control law.
In the second half of this fiscal year, experimental data for large scale coil will be obtained at HFLSM in the framework of the Kakenhi S “Magnet technology development for 50T cryogen-free high temperature superconducting magnet”. The expanded model will be applied to it, which will make it possible to test the possibilities of adapted current control to obtain stable field value on a full size coil.
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| 次年度使用額が生じた理由 |
As mentioned in the scientific report, there was an unexpected delay to procure a computation computer, due to a shortage of components worldwide.
Some of the components were completely unavailable, alternatives had long delivery delays and/or were less cost efficient. As during this first year the project could be conducted without that equipment, it was decided to postpone the acquisition until the shortage was solved.
The situation is now getting better even if unusual delivery delays still exists. We will proceed with the procurement in the first part of this fiscal year.
As for the travel expenses, during this first year the travel restrictions limited their use: exchanges with colleagues especially at CNRS Grenoble (France) were moved to online meeting. It is our desire to reassign this budget toward the computing equipment.
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