Results of ITER TF Coil Double Pancake Heat Treatment in Japan

Kajitani, Hideki; Nakamoto, Mio; Yoshizawa, Kazumi; Uno, Y.; Kawasaki, Tsutomu; Matsui, K.; Koizumi, N.; Nakahira, Masataka

doi:10.1109/tasc.2022.3147728

Cited by 3 publications

(3 citation statements)

References 6 publications

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“…In DP manufacturing, a Nb 3 Sn cable-in-conduit (CIC) conductor is wound to Dshape; subsequently, Helium inlet and terminal joint box are installed to particular part of the conductor [6,7]. The wound conductor with helium inlet and terminal joints is heat treated to generate an Nb 3 Sn layer at 650 • C for a few weeks [8]. Radial plates (RPs) are manufactured in parallel to the conductor winding and heat treatment.…”

Section: Dp and Wp Manufacturing Proceduresmentioning

confidence: 99%

Completion of all Winding Packs for ITER Toroidal Field Coils in Japan

Kajitani

Nakamoto

Suwa

et al. 2023

Plasma and Fusion Research

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In Japan, National Institutes for Quantum Science and Technology (QST) has the responsibility to develop nine toroidal field (TF) coils, each of which consists of a winding pack (WP) and coil case for the ITER project. The WP consists of seven double-pancakes (DPs), which consist of conductors inserted into D-shaped radial plates (RPs). Although a WP is significantly large (14 m high and 9 m wide), the position of the current center line of the WP must be controlled within a few millimeters. Therefore, numerous technical challenges arose in DP and WP manufacturing. Herein, in the RP manufacturing, the optimization of welding and machining procedures, and accurate manufacturing techniques were established. Subsequently, all RPs were fabricated around the flatness errors of 1 mm from the nominal. In cover plate (CP) welding, the welding procedure was optimized so that a good DP flatness after CP welding was achieved. In the WP insulation, by developing a method to insulate a WP while applying compression, the dimensions within errors of a few milli-meters is achieved in all of WPs. Consequently, all nine WPs were successfully completed for TF coils in Japan in March 2022.

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Section: Dp and Wp Manufacturing Proceduresmentioning

confidence: 99%

Completion of all Winding Packs for ITER Toroidal Field Coils in Japan

Kajitani

Nakamoto

Suwa

et al. 2023

Plasma and Fusion Research

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“…The ITER magnet system has 18 Toroidal Field (TF) coils for plasma confinement. National Institutes for Quantum Science and Technology (QST), as the Japan Domestic Agency (JADA), is responsible for the procurement of 9 ITER TF coils and 19 TF coil cases (CCs) [1][2][3][4][5][6]. Figure 1 illustrates a winding pack (WP) and CC of the TF coil.…”

Section: Introductionmentioning

confidence: 99%

“…The WP with 7 pancake coils made of 68 kA class Nb 3 Sn conductors is integrated into the CC withstanding several-hundred-MN electromagnetic forces. Procedure of the TF coil integration [4] is as follows, (1) half of CC with opened surface is placed on the floor with its inner board facing down, (2) WP is inserted into the CC, (3) another half of the CC with opened surface is placed over the WP, (4) interface of the two halves of CC is welded, (5) opened surface of the CC is closed with plates (closure welding), (6) the gap between CC and WP is filled with epoxy resin (gap filling). During the TF coil integration process, current center line (CCL) is controlled with accuracy of 1.3 -3.0 mm [4,7].…”

Section: Introductionmentioning

confidence: 99%

A Double Check Process for CCL Positional Plates in ITER TF Coil Integration

HASEGAWA

TSUTSUMI

SAITO

et al. 2023

Plasma and Fusion Research

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A current center line (CCL) was precisely controlled with markers called "CCL positional plates (CCLPPs)" during the ITER toroidal filed (TF) coil integration. CCLPPs with the same x and y coordinates (CCLPP pair) are attached on both sides of the TF coil Winding Pack (WP). The CCLPP insufficiently fixed has to be replaced with new one to ensure the accuracy of CCL. On the other hand, the replacement possibly leads to some issues, such as, dropping the CCLPP into the CC and damaging the WP. Thus, unnecessary replacement should be avoided. We have therefore implemented a double check process to confirm soundness of the CCLPPs. First, change of the distance of CCLPP pair (∆W CCLPP ) is evaluated (Check A). However, ∆W CCLPP would be influenced by the WP deformation. Thus, the Check A possibly judges the fixing condition of the CCLPP as "unusual" even if it has no issue. This may lead to the unnecessary replacement of the CCLPP. To avoid the unnecessary replacement, the local displacement of each CCLPPs (∆r CCLPP ) is also evaluated (Check B). In this paper, we define the criteria for "unusual" ∆W CCLPP and ∆r CCLPP based and verify its validity for the TF coil integration by considering the measurement error and geometrical configuration of the CCLPPs. In the case of one Toshiba TF coil, the double check process confirmed that CCLPPs were insufficiently fixed, and they were successfully replaced to the new ones. Thus, it was demonstrated that the proposed criteria indicated the appropriate action to keep the CCLPP soundness. The method proposed in this paper would be powerful tool to inspect the soundness of the CCLPP which is important for the CCL control not only in the ITER TF coil, but also in the future fusion magnets.

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Analysis of Temperature Uniformity During Heat Treatment of Nb₃Sn Coils for DC Magnet in Super-X Test Facility

Wu,

Deng,

et al. 2024

IEEE Trans. Appl. Supercond.

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Results of ITER TF Coil Double Pancake Heat Treatment in Japan

Cited by 3 publications

References 6 publications

Completion of all Winding Packs for ITER Toroidal Field Coils in Japan

Completion of all Winding Packs for ITER Toroidal Field Coils in Japan

A Double Check Process for CCL Positional Plates in ITER TF Coil Integration

Analysis of Temperature Uniformity During Heat Treatment of Nb₃Sn Coils for DC Magnet in Super-X Test Facility

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Results of ITER TF Coil Double Pancake Heat Treatment in Japan

Cited by 3 publications

References 6 publications

Completion of all Winding Packs for ITER Toroidal Field Coils in Japan

Completion of all Winding Packs for ITER Toroidal Field Coils in Japan

A Double Check Process for CCL Positional Plates in ITER TF Coil Integration

Analysis of Temperature Uniformity During Heat Treatment of Nb3Sn Coils for DC Magnet in Super-X Test Facility

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Analysis of Temperature Uniformity During Heat Treatment of Nb₃Sn Coils for DC Magnet in Super-X Test Facility