Coil Fabrication on Site
For the poloidal field coils under European responsibility, the different stages of fabrication—winding, impregnation, stacking, cold testing—were carried out on stations in this production facility on the °ÄÃÅÁùºÏ²Ê¸ßÊÖ site.
One of only two manufacturing facilities located on the °ÄÃÅÁùºÏ²Ê¸ßÊÖ site, the Poloidal Field Coils Winding Facility was constructed by Europe to house the winding and assembly activities for four of °ÄÃÅÁùºÏ²Ê¸ßÊÖ's giant ring-shaped magnets.
Ranging in diameter from 17 to 24 metres and weighing 200 to 400 tonnes, coils PF2, PF3, PF4, and PF5 were simply too big to be manufactured off site and shipped to °ÄÃÅÁùºÏ²Ê¸ßÊÖ.
The 250-metre-long facility was equipped with the high-tech machinery and handling equipment required to carry out the successive stages of the fabrication process, from winding the building blocks of each coil, to stacking and creating the final assembly, to cold testing. In April 2021, the first European-made coil, PF5, successfully completed all manufacturing and testing and was removed from the facility and stored until its installation in September 2021. A third completed coil, PF2, left the facility in December 2021 and is stored on site; PF4 and PF3 followed respectively in August 2023 and May 2024. European poloidal field coil procurement activities have now concluded, and the building will be fully transferred to the °ÄÃÅÁùºÏ²Ê¸ßÊÖ Organization for other machine assembly activities.
The manufacturing process
The raw material for the four coils—niobium-titanium (NbTi) cable-in-conduit superconductor—was produced in China and delivered to the Poloidal Field Coils Winding Facility on 20-tonne spools.
In the winding stage of fabrication, the conductor was uncoiled from the spools and straightened before passing through cleaning and sandblasting machines that prepared its surface to receive several layers of glass-fibre insulating tape. Rotating tape heads entered into action as the conductor, fed from two spools simultaneously, joined the tooling table to be "turned" into the precise dimensions required for each coil. The resulting component was a spiralled, two-layer coil called a double pancake that weighed between 20 tonnes (PF2) and 34 tonnes (PF3). In all, 30 double pancakes were wound in the facility to build four coils.
Next, the double pancake was transported by overhead crane to the vacuum pressure impregnation (VPI) station and lowered into a custom-fit mould. Epoxy resin, injected over the course of several hours, filled all gaps and hardened the glass tape under the effect of heat and pressure. A 36-hour "curing" phase at 140 °C completed the process, which gave the double pancake rigidity and ensured electrical insulation.
The rigid double pancake winding was transferred to the winding pack assembly area of the building where it was stacked with other double pancakes and joined together. A second vacuum impregnation was performed to harden the entire assembly and components such as clamps, protection covers and helium pipes were added.
The final step in coil production was cold testing, during which the completed poloidal field coils were repeatedly cooled to low temperature (approximately 80 K) in order to simulate the thermal stresses and the work conditions that will be experienced during operation, then brought back to room temperature.
Poloidal Field Coil Fabrication facts:
- Coil production: 2017-2024
- Coils manufactured on site: PF2, PF3, PF4, PF5
- Diameter of coils: from 17 metres (PF2, PF5) to 24 metres (PF3, PF4)
- Amount of NbTi cable-in-conduit superconductor per coil: from 6 km (PF2) to 14 km (PF3)
- Number of double pancakes per coil: six (PF2) or eight (PF3, PF4, PF5)
- Number of double pancakes produced on site: 30
- Weight of final assemblies: 200 to 400 tonnes
- Coil completion dates: PF5 (2021); PF2 (2021); PF4 (2023), PF3 (2024)
- Procurement responsibility: Europe
Photo Gallery
European poloidal field coils: the end of an era
2024-06-20 - With the completion of poloidal field coil #3 (PF3) in April, the ten-year effort to procure six ring-shaped coils for °ÄÃÅÁùºÏ²Ê¸ßÊÖ came to a close. On 20 June, Fusion for Energy (the European Domestic Agency), the °ÄÃÅÁùºÏ²Ê¸ßÊÖ Organization, and industry representatives celebrate a massive accomplishment and the end of an era.
Final coil leaves moves into storage
2024-04-30 - The last poloidal field coil manufactured on site by the European Domestic Agency is moved into storage on 30 April. The completion of PF3—one of the two largest ring-shaped coils, measuring 24 metres in diameter—marks the high point of technical and organizational expertise accumulated since manufacturing began in the Winding Facility in late March 2017.
Completion of PF3
2024-04-16 - On 16 April 2024, workers from Fusion for Energy, °ÄÃÅÁùºÏ²Ê¸ßÊÖ Organization, APAVE, ASG, S&I, MAMMOET and CNIM operators celebrate the completion of PF3. The 24-metre-in-diameter coil is equipped with 17 lifting accessories (red).
PF3 successfully completes cold tests
2024-03-21 - Poloidal field coil #3—the final coil to be supplied by Europe—completes cold tests in March 2023.
Last ring coil in cold test chamber
2024-03-14 - In the European coil winding facility on site, poloidal field coil #3 is undergoing a test campaign inside a cryostat (pictured) designed to perform a cold test at 80K. While not the final operating temperature of 4 K, tests at 80 K provide important information to the manufacturing team and quality inspectors.
Ring-coil fabrication: spreader beam no longer needed
2023-10-12 - In the Poloidal Field Coils Winding Facility, a spreader beam (lifting capacity: 48 tonnes) was used under the overhead crane to balance the weight of the individual double pancake windings as they were transferred from the winding table. This phase of fabrication is over, and the spreader beam was dismantled in October.
Building use will change
2023-10-06 - The last ring coil in construction, PF3, is barely visible at the far end of the European coil winding facility. What is evident is that the building is being used in a new way as equipment is moved out. In the foreground, thermal shield panels are stored awaiting replacement or repair. Photo: °ÄÃÅÁùºÏ²Ê¸ßÊÖ Organization/EJF Riche
Last ring coil
2023-09-29 - In the European winding facility, teams are putting the finishing touches on poloidal field coil #3 (PF3). This is the last coil expected. Progressively, the building is being handed over for other assembly purposes. Photo: °ÄÃÅÁùºÏ²Ê¸ßÊÖ Organization/EJF Riche
PF4 moved to storage
2023-08-08 - On 8 August, poloidal field coil #4 (24 metres in diameter, 350 tonnes) is moved from the European Poloidal Field Coils Winding Facility to storage on site. Only one coil, PF3, remains to be completed by Europe.
5 of 6 ring magnets completed
2023-07-07 - With the successful conclusion of cold testing, poloidal field coil #4 (PF4) is ready to leave the European winding facility. Only one more coil remains to be finalized: PF3.
Cold test ends
2023-05-06 - The cold test of poloidal field coil #4 (PF4) has ended. Stay tuned for the lifting of the lid of the cryogenic chamber.
Winding facility: progressive handover begins
2023-04-03 - As poloidal field coil manufacturing activities wind down, the European Domestic Agency is progressively handing over the building to the °ÄÃÅÁùºÏ²Ê¸ßÊÖ Organization, which will use the space for assembly activities. On 3 April, approximately 25% of the shop floor was officially transferred. See more at: /newsline/-/3865
One over the other
2023-02-20 - The last two poloidal field coils to be produced in the European winding facility on site are now quite advanced. In this picture, as coil PF4 (black, at top) heads to cold testing, it passes over the PF3 winding pack (white).
Reproducing a daunting environment
2023-02-20 - Inside the cryostat, the coil will experience extreme cold, intense pressure, high voltage and considerable thermal stresses—a foretaste of its life to come in the daunting environment of a burning plasma.
Last step for PF4
2023-02-20 - Only one step remains for completed poloidal field coil PF4—cold testing. Cold testing will take several months, as the coil is slowly brought to a target temperature of 80 K (-193 °C), stabilized, then brought back to room temperature. Tests are planned during every stage of the process.
Colleagues teaching colleagues
2022-09-17 - Standing above the production line, in the visitors gallery, is the best way to understand the entire process. It also helps to have an expert guide to talk you through the steps ...
First stop: the European winding facility
2022-09-17 - Families participating in the first-ever °ÄÃÅÁùºÏ²Ê¸ßÊÖ Family Open Doors Day in September are guided through the poloidal field winding facility, where the two largest coils are still in fabrication.
Winding station: 7 years of faithful service
2022-09-08 - Thirty production double pancakes for four poloidal field coils were created on the winding table installed in the building by Sea Alp Engineering (Italy). With no more to produce, the table was dismantled in August 2022. (See: /newsline/-/3791)
Coil PF4 in its mould
2022-07-25 - In July, contractors to the European Domestic Agency carry out the vacuum pressure impregnation (VPI) of poloidal field coil #4. During the process, epoxy resin is injected at a temperature of 50 °C, then heated to 140 °C by a strong electrical current fed to the conductors (the Joule effect) and by electrical resistances positioned around the mould. VPI confers rigidity to the winding pack and ensures electrical insulation.
The long view
2022-07-21 - The coil production line in the 250-metre, on-site production facility where the European Domestic Agency for °ÄÃÅÁùºÏ²Ê¸ßÊÖ, Fusion for Energy, is producing four poloidal field coils. Two have been finalized (including one already installed in the Tokamak pit) and two others are in the last stages of production.
Last double pancake!
2022-06-23 - After close to five years of intense activity, the winding table at the south end of the European poloidal field coil factory on site is now empty. In June, the final circular conductor arrangement ("double pancake") required for the last ring-shaped coil was finalized and moved to the next workstation. Since production began in August 2017, 30 double pancakes have been produced for four poloidal field coils.
Relief and satisfaction
2022-06-23 - Members of the CNIM team (Toulon, France) celebrate the end of double pancake winding. CNIM was the European subcontractor responsible for manufacturing and cold testing. © F4E
Poloidal field coil #4 in fabrication
2022-04-14 - Eight double pancakes have been stacked and joined and now poloidal field coil #4 (PF4) is being prepared for vacuum pressure impregnation, which confers electrical insulation to the magnet and creates a rigid assembly.
Spool after spool
2022-01-20 - Fifty-six spools, each weighing 16 tonnes and containing 900 metres of jacketed superconducting cable, have already been used in the onsite manufacturing of the °ÄÃÅÁùºÏ²Ê¸ßÊÖ poloidal field coils.
Final double pancakes for PF3
2022-01-20 - This is a double pancake for poloidal field coil #3, the last one of four to be manufactured in this on-site European winding facility. It is 24 metres in diameter.
Manual wrapping, nine layers
2022-01-20 - Prior to final resin impregnation, coils are manually wrapped with nine successive layers of glass-Kapton tape that provide efficient electrical insulation. (In the photo is coil PF4.)
Joining conductor "terminations"
2022-01-20 - Conductor lengths have to be joined at their ends. In this photo, the European teams are preparing a termination "joggle" by bending the conductor to align with another conductor end.
Another ring magnet delivered
2021-12-17 - Poloidal field coil #2 is removed from the winding facility after its completion and moved into storage. PF2 is the second ring magnet to be produced by the European Domestic Agency on site.
Making way for others
2021-12-17 - Poloidal field coil #2 (PF2) is moved into storage to make way for the assembly of two other ring coils, PF4 and PF3. Both are in production now.
After impregnation
2021-11-09 - After impregnation, the double pancake is structurally rigid and the coil turns are electrically insulated from one another.
Fusion for Energy
2021-11-09 - The European agency for °ÄÃÅÁùºÏ²Ê¸ßÊÖ, Fusion for Energy, is procuring 5 of the 6 poloidal field coils for the project; (a sixth, PF1, is procured by Russia). Four are too big to travel by road and are manufactured instead in Europe's on-site winding facility.
Takes a team
2021-11-09 - The successful completion of the coils is dependent on the collaboration of many actors, including the European Domestic Agency (Fusion for Energy, procuring party), ASG Superconductors (engineering integration), Dalkia (site and infrastructure), and CNIM (fabrication).
PF2 nears finalization
2021-11-09 - The last "medium size" poloidal field coil undergoes inspection in Europe's on-site winding facility. With a diameter of 17 metres it is bigger than coils #1 and #6 (9/10 metres in diameter) and smaller than coils #4 and #3 (24 metres in diameter).
Custom fit
2021-11-09 - All tooling had to be expanded for the two coils measuring 24 metres in diameter—PF4 and PF3. (The first two coils had a diameter of 17 metres.)
Stacking PF4
2021-11-09 - Seven out of eight double pancakes for coil #4 (PF4) are now stacked. This technician is carrying out dimensional verifications.
Critical tests
2021-11-09 - Helium tests are underway at critical points along the sixth double pancake for PF3, which is in production in Europe's on-site coil winding facility.
Resin time for this double pancake
2021-11-09 - A double pancake has been sealed tightly into its resin chamber. Epoxy resin, injected over the course of several hours, will fill all gaps and harden the glass insulation tape under the effect of heat and pressure. A 36-hour "curing" phase at 140 °C completes the process.
Second ring coil completed on site
2021-10-29 - In the Poloidal Field Coils Winding Facility on site, European contractors have completed a second ring-shaped magnet. Poloidal field coil #2 (PF2) is 17 metres in diameter, like PF5 that preceded it. © Les Nouveaux Médias/SNC ENGAGE
Busy factory
2021-10-29 - In this 250-metre-long facility, European contractors are currently producing the building blocks (the individual double pancakes) for the last of four poloidal field magnets—PF3, which has a diameter of 24 metres. © Les Nouveaux Médias/SNC ENGAGE
PF2: Successful cold tests
2021-10-15 - Cryotests on PF2 have successfully concluded and the team gathers in celebration. (The 200-tonne coil is seen here in its open vacuum chamber.)
PF4 is underway
2021-09-16 - In Europe's on-site facility for poloidal field coil manufacturing, the teams are creating the individual double pancakes for PF4, a coil that is 24 metres in diameter. After PF5 (installed in the pit) and PF2 (nearly completed), PF4 will be the third ring-shaped magnet to leave the facility.
PF5 enters pre-assembly theatre
2021-07-27 - Metrology and rigging must be performed on poloidal field coil #5 before it can be installed in September in the Tokamak pit.
Into storage
2021-04-16 - Officially handed over to the °ÄÃÅÁùºÏ²Ê¸ßÊÖ Organization and safely placed in storage, PF5 will wait its turn in the machine assembly sequence.
First coil exits manufacturing facility
2021-04-16 - The 340-tonne, 17-metre-in-diameter coil slowly exits the European winding facility on 16 April 2021.
36 axels, 144 wheels
2021-04-16 - Three self-propelled modular transporters, piloted in sync and powered by 1000 HP hydraulic power packs took care of the transfer.
Two sizes
2021-03-10 - Poloidal field coil #5 (PF5) is the second ring coil procured by the European Domestic Agency. Here PF5 is seen inside of one of the double pancakes that has been wound for PF4, which is a larger coil (24 metres in diameter vs 17 metres in diameter).
PF5 completes cold testing
2021-02-12 - Following in the footsteps of poloidal field coil #6 (PF6), which completed all tests in December 2020, PF5 is the second ring-shaped coil out of six to check all the boxes. During the final-phase thermal tests, the coil was inserted into a dedicated cryogenic chamber and cooled down to approximately 80 K (-193 °C), then cycled between cooldown and warmup.
PF5 passes cold tests
2021-02-10 - In the European workshop on site, poloidal field coil #5 has completed cold testing and will be removed from its cryogenic chamber.
Pending installation
2021-01-27 - Some light equipment work (such as the addition of protective covers) will be performed while the component is in storage.
400-tonne coil moves to temporary storage
2021-01-27 - Poloidal field coil #6 is transported from the European winding facility on site to a temporary storage facility. It will be the first magnet coil to be inserted into the Tokamak pit in April 2021. Three other ring coils are in various stages of fabrication on site.
Fabricating the double pancakes for PF4
2021-01-22 - Data fed by approximately one hundred sensors is displayed on large screens and closely examined by the Fusion for Energy team responsible for the impregnation of the first of the eight double pancakes required for poloidal field coil #4.
A whole battery of tests
2020-12-15 - In addition to thermal testing, PF6 has successfully passed global leak tests, electrical tests, and high voltage tests.
For a careful lift
2020-12-15 - As soon as a double pancake for PF4 is completed, it is transferred carefully with the help of this circular spreader beam (40 tonnes) to the impregnation, and then the assembly tables.
The middle poloidal field coils are larger
2020-12-15 - The tooling has been widened, and work is underway on the first double pancakes of PF4 (24 metres in diameter). PF4 and PF3 (not yet started) are the largest poloidal field coils of the °ÄÃÅÁùºÏ²Ê¸ßÊÖ machine.
Coil #6: ready for installation
2020-12-14 - Poloidal field coil #6—the bottommost ring coil of the °ÄÃÅÁùºÏ²Ê¸ßÊÖ machine and the first in line for installation—has completed all testing on site in the European winding facility. Pictured: representatives from the European Domestic Agency (procuring agency), China's ASIPP (manufacturer), and ASG Superconductors (engineering integrator).
After three months in the chamber
2020-12-10 - During thermal testing, the coil was inserted into a dedicated cryogenic chamber and cooled down to approximately 80 K (-193 °). Three full cooldown and warmup cycles were performed, each one requiring approximately one month.
Cold testing poloidal field coil #5
2020-12-09 - A second poloidal field coil—PF5—enters its cryogenic chamber on site for cold testing.
Both 17 metres in diameter: PF5 and PF2
2020-11-23 - PF5 undergoes laser dimensional inspection before insertion into its cryogenic chamber. In the background, PF2 (the second coil produced on site) has been enclosed inside the coil impregnation station. Photo: °ÄÃÅÁùºÏ²Ê¸ßÊÖ Organization/EJF Riche
PF6 enters the cryogenic chamber
2020-09-08 - PF6 is now in its cryogenic chamber, as the team prepares for thermal testing at 80 K. Poloidal field coil #6 (PF6) was fabricated by the ASIPP Institute in China under contract with the European Domestic Agency, and then sent to Europe's on-site winding facility for testing.
Perfect fit
2020-08-19 - The gantry crane lowers the 400-tonne coil (PF6) into its cryogenic chamber. In addition to a cooldown to 77 K, the coil will be submitted to a pressure drop test, several leak tests (at cooldown and after warmup) and a 100A current test.
PF6 unwrapped
2020-07-31 - At one end of the European winding facility on site, poloidal field coil #6 (PF6) sits unwrapped. The team is preparing the magnet for cold testing before insertion in the Tokamak pit later this year.
Three in a glance
2020-07-16 - Three poloidal field coils are now present in Europe's on-site winding facility: poloidal field coil #5 (PF5, far left, black) is being equipped with helium piping and electrical cables; PF2, of similar diameter (white, centre left) is ready for the impregnation stage; and PF6 (far right, under the crane) is being prepared for cold testing.
Recent arrival
2020-07-09 - Poloidal field coil #6, recently delivered from China, still sits on its transport frame.
Preparing for cold testing
2020-07-09 - The first magnet coil produced in the European winding facility on site is PF5 (pictured). The teams are preparing for cold testing.
PF5 in line for cold testing
2020-06-30 - The fifth poloidal field coil (PF5) is now fully assembled, including protective plates and clamps (18). The next step is cold testing.
PF6 arrives!
2020-06-26 - Procured by Europe and manufactured in China, the ring-shaped magnet coil PF6 will be the first to be integrated into the °ÄÃÅÁùºÏ²Ê¸ßÊÖ machine. The massive component arrived on site on Friday 26 June 2020 after a 10,000-kilometre voyage from its manufacturing site in Hefei, China.
Extension going up
2020-06-15 - An extension of the Poloidal Field Coils Winding Facility will create additional space for the handling of the next set of double pancakes to be produced for poloidal field coil #4 (24 m in diameter).
PF2: impregnation next
2020-06-04 - Nine layers of ground insulation wrapping have been applied and lifting tool interfacing elements have been attached. The next step for poloidal field coil #2 (PF2) is transport to the vacuum pressure impregnation station.
Final stages for poloidal field coil #5
2020-06-04 - The first coil produced on site by the European Domestic Agency in the Poloidal Field Winding Facility is PF5. Following successful impregnation, the hardened coil is now receiving protective plating (yellow in the picture, spaced regularly). Clamping trials (foreground) are also underway.
Winding station set up
2020-06-04 - Les stations de travail qui ont servi à la fabrication des bobines PF5 et PF2 sont en cours d'élargissement (de 17 à 24 mètres de diamètre) pour les deux prochaines bobines. La station de bobinage sur la photo tournera bientôt de nouveau pour créer les bobinages de PF4.
Spreader beam
2020-05-15 - This 40-tonne spreader beam supports the double pancakes at many points, allowing them to be transported without tilting. © Les Nouveaux Médias/SNC ENGAGE
Working on a dummy
2020-05-01 - A dummy double pancake is underway for poloidal field coil #4 (PF4)—a prerequisite to starting actual fabrication this summer. © Les Nouveaux Médias/SNC ENGAGE
Cold chamber
2020-05-01 - A second cryogenic chamber is under construction for poloidal field coil #5 (PF5), which will be the second European coil to undergo cold testing. © Les Nouveaux Médias/SNC ENGAGE
Larger width
2020-05-01 - The teams are currently setting up the work tables they will need for poloidal field coils 4 and 3, which are larger in diameter--24 metres instead of 17. © Les Nouveaux Médias/SNC ENGAGE
Celebrating the penultimate step
2020-04-11 - Poloidal field coil #5 (PF5)—the first coil produced by Europe in its on-site winding facility—is lifted from the impregnation station to the final assembly station. Partners in the successful works are: the ASG consortium, MAMMOET (formerly ALE), Bureau Veritas (regulatory control of the gantry crane), and Fusion for Energy, the European Domestic Agency.
Gantry crane in action
2020-04-11 - The 280-tonne impregnated winding pick is lifted by gantry crane and transported to the assembly station where clamps and other components will be attached. When the coil leaves the building, it will weigh 342 tonnes.
A production line
2020-04-11 - In the background, PF5 is discernible under the red gantry crane as it is moved to the final assembly station. In the foreground, European contractors are working on the ground insulation of the PF2 winding pack. In one month, a coil manufactured for Europe in China, PF6, will arrive for cold testing in one of the silver cryogenic chambers seen to the far right of the image.
Cryogenic chambers ready
2019-12-13 - The cryogenic chamber for PF6 stands ready for the arrival of the completed coil from China early next year. The red gantry crane will be used to lift the 400-tonne component in and out of the chamber. A second chamber for PF5 has also been assembled.
Next step for PF5: impregnation
2019-12-13 - A mould has been assembled and welded around the first on-site production coil—PF5. After the impregnation process, which will last about three weeks, the coil will be prepared for cold testing at 80 K.
Building blocks for PF2
2019-12-13 - Work is underway to wind and impregnate the double pancake windings for poloidal field coil #2 (PF2).
Impregnation: a three-week operation
2019-12-12 - The casing assembled around the PF5 winding pack must be absolutely leak tight. Approximately 2,200 litres of resin will be injected over 60 hours, followed by a period of "gelling" and "curing."
Last double pancake for PF2
2019-12-12 - The last of six double pancakes for poloidal field coil #2 (PF2) is being wrapped with insulating tape ... the final step before transfer of the double pancake to its impregnation station. The first two coils produced in the facility are not identical, although both are 17 metres in diameter. PF5 is built from 11.5 km of niobium-titanium conductor (8 double pancakes) and will weigh 342 tonnes when completed; PF2 is built from 6 km of conductor (6 double pancakes) and will weigh 204 tonnes when completed.
Winding tooling to be reconfigured
2019-12-12 - The winding tooling used for PF5 and PF2 has now been disassembled. It will be reconfigured for the winding of the last two poloidal field coils to be produced in this facility—PF3 and PF4, which have a diameter of 24 metres.
Progress on PF5—the first poloidal field coil produced on site
2019-11-25 - Poloidal field coil #5 (PF5), 17 metres in diameter, is the first coil produced by European Domestic Agency contractors in the winding facility on site. Coil vacuum pressure impregnation—when the entire winding pack is "impregnated" with epoxy resin to form a hardened assembly—is about to start.
PF5, ready for impregnation
2019-11-13 - A mould will be constructed tightly around the coil winding pack (built from eight double pancakes, stacked and joined). The impregnation process that follows will create a rigid assembly.
Production line
2019-11-13 - The 257-metre-long European winding facility is completely filled with workstations, from winding all the way through to cold testing.
Termination station
2019-11-12 - European Domestic Agency contractors (from CNIM, France) are working on the termination of double pancake joints.
Soon, impregnation
2019-11-06 - The PF5 winding pack has been moved to the next station, in preparation for impregnation.
A chamber for the first-built coil
2019-06-18 - This cryogenic chamber is dimensioned especially for poloidal field coil #6 (PF6) which, at 10 metres in diameter, is the second smallest ring magnet. The coil will arrive this autumn from China, where it was manufactured on behalf of the European Domestic Agency. Cold tests will take place in this chamber at 80 K. Photo: °ÄÃÅÁùºÏ²Ê¸ßÊÖ Organization/EJF Riche
One atop the other
2019-05-16 - Stacking is proceeding well for the double pancakes of poloidal field coil #5 (PF5). The teams must then connect the pancakes to ensure the flow of cryogenic helium—both between the double layers of each pancake (an "intra pancake joint"), and between each double pancakes (an "inter pancake joint").
Stacking
2019-03-07 - Impregnated double pancakes are stacked and joined to form the final coil. Here we see five of PF5's eight double pancakes stacked, as well as intra- and inter-pancake joints for helium flow.
New winding activities
2019-03-07 - Winding activities have begun on PF2—the second of four coils to be produced by Europe in this manufacturing facility on site. With a few adaptations, the equipment set up to wind the first production coil, PF5, can serve again to wind the double pancakes required for PF2, as both coils measure 17 metres in diameter.
Cold tests at 80 K
2019-03-07 - Two cryogenic chambers are being assembled for the final stage of fabrication—cold testing at 80 K, which will permit contractors to test the behaviour of the completed coils under thermal constraint. One chamber will serve for PF5, the other for PF6 (manufactured in China on behalf of Europe and delivered at the end of 2019).
Test mockup
2019-03-07 - This "piece" of mockup coil faithfully mimics poloidal field coil #5 (PF5) and its eight stacked double pancakes. The winding pack impregnation operation will be tested first on this mockup before being carried out on PF5.
Before impregnation
2018-10-10 - Six of the eight double pancakes needed for PF5 have been wound. This staging table is used to prepare the double pancakes for the next stage—impregnation.
Final step: Cold testing
2018-10-10 - This cryogenic chamber will permit a final coil assembly to be tested at low temperature (approximately 80 K) in order to simulate the thermal stresses and the work conditions that will be experienced during operation. In this way, the performance of the coils will be tested before their installation in the °ÄÃÅÁùºÏ²Ê¸ßÊÖ machine.
First step: winding
2018-10-10 - Two spools of niobium-titanium conductor are simultaneously fed onto the winding table to create a double pancake (a double layer of spiralled conductor.) The winding table in the picture is dimensioned for PF5 and PF2. Later, for the two larger coils PF3 and PF4 (24 metres in diameter), it will be expanded.
A team of 70
2018-10-10 - A team of 70 people is working daily to meet a tight production schedule. Here, the technicians are monitoring the impregnation of one double pancake.
Second step: impregnation
2018-10-10 - For the second phase of operations, the double pancake windings are transferred by overhead bridge crane to the impregnation area in the centre of the winding facility. The cranes lower the double pancakes into moulds for vacuum pressure impregnation (VPI) with epoxy resin. The resin—acting inside of a sealed mould and under the effect of heat—hardens the glass tape to bond each double pancake into a rigid assembly.
A series of workstations
2018-10-10 - Technicians are active at all of the workstations of the Poloidal Field Coils Winding Facility, either performing work on the first production unit PF5, or qualifying later stages. The European Domestic Agency reports that, all activities combined, the first coil is 42 percent complete.
Glass-fibre tape
2018-10-10 - During the winding process the conductor is wrapped with several layers of glass-fibre tape, which insulates the conductor turns one from another.
A larger mould for the stacked assembly
2018-10-10 - The rigid double pancakes will be stacked and joined electrically to form the winding pack (in the case of PF5, eight double pancakes will be stacked). The final assembly will undergo a second impregnation process in this larger mould. Notice in the foreground, a segment of mockup winding that was created from multiple layers of dummy impregnated conductor lengths to test all processes.
Ring magnet fabrication in full swing
2018-10-10 - Beginning with conductor winding and ending—at the other side of the 257-metre-long facility—with final assembly and cold testing, the fabrication of °ÄÃÅÁùºÏ²Ê¸ßÊÖ's ring shaped magnets is a precise step-by-step process.
A precise mould
2018-10-10 - The mould is custom built around the double pancake to be impregnated. Current passed through the conductor heats the double pancake to approximately 80 degrees Celsius, all air is removed, and resin is injected slowly to fill all nooks and crannies.
Cold testing equipment
2018-07-26 - On the far end of the building, teams are installing equipment for the cold testing (at 80 K) of the completed magnets. Photo: °ÄÃÅÁùºÏ²Ê¸ßÊÖ Organization/EJF Riche
Testing performance
2018-07-26 - Finished magnets will be inserted here and cooled to low temperature (approximately 80 K, or -193 °C). Photo: °ÄÃÅÁùºÏ²Ê¸ßÊÖ Organization/EJF Riche
Turning tables and hot resin
2018-07-18 - One double pancake for PF5 is undergoing impregnation in the background, while assembly is underway on the impregnation mould for another.
Precise welding operations
2018-07-18 - This "termination box" is welded to the jacket of conductor on one end with a stainless steel pipe for liquid helium cooling exiting on the other end.
Creating a cold room
2018-07-18 - The cold test chamber has been delivered in segments. Here we see how the magnet coils will be enclosed in a tube-like structure.
Installing the final work station
2018-07-17 - European contractors are installing a cold test chamber for the last phase of production: cooling the completed coil to approximately 80 K (-193 °C) in order to simulate the thermal stresses and the work conditions that will be experienced during operation.
Creating a "joggle"
2018-07-17 - After completing the winding, the next step is to shape the "terminations"—the areas that connect one conductor length electrically to another, or one double pancake to another. A portion of conductor is opened, the turn insulation is removed and moulds are brought close to the double pancake to shape its end into a "termination joggle."
Working on double pancake number six
2018-07-17 - European contractors are winding the sixth in the series of eight double pancakes required by PF5. The winding table rotates slowly as conductor is fed simultaneously from two spools in a process known as "two-in-hand" winding.
Next step: hot resin
2018-04-09 - Attached to the circular spreader beam, one of three finalized double pancakes (out of eight needed to complete the winding pack for PF5) is prepared for impregnation operations.
Impregnation table
2018-04-09 - Technicians are busy assembling the vacuum containment vessel—the ''mould''—that will enclose the double pancakes throughout the lengthy and delicate resin impregnation process.
Qualifying the impregnation step
2018-04-09 - Resin-impregnation procedures were tested on this double pancake ''dummy''—a perfect replica of the conductor, only made of copper instead of the superconducting niobium-titanium alloy.
Load tests on new crane
2018-02-25 - The new gantry crane in the Poloidal Field Coils Winding Facility has a nominal lifting capacity of 400 tonnes. It was tested in February at 125% of nominal (static) and 110% of nominal (dynamic), with successful results.
Witnessing
2018-02-25 - The gantry crane is made up of a 30-metre-in-diameter steel structure supported by four hydraulic towers traveling on rails, capable of lifting the heaviest components of the ring-shaped coils throughout the last stages of fabrication.
Next: impregnation qualification
2018-01-31 - In January, teams are setting up for impregnation qualification activities. Photo: F4E
Work proceeding
2018-01-31 - Double pancake winding continues for poloidal field coil #5 (PF5). Eight pancakes will be stacked to form the final coil. Photo: F4E
Behemoth crane
2017-12-11 - Four hydraulic towers and circular beam in a square frame form the 30-metre-in-diameter gantry crane, capable of lifting 400 tonnes.
Crane enters building
2017-12-11 - In December, the new gantry crane was delivered to its installation location on the north end of the building, where it will be installed on its four "legs."
Second pancake
2017-11-27 - Work is underway on the second production double pancake.
All the stations
2017-11-27 - While double pancake winding is underway in the foreground, European contractors are preparing the second station—impregnation—for qualification tests.
First pancake wound
2017-09-19 - The first production double pancake has been placed in a staging area so that additional activities can be carried out (the addition of terminations, the brasing of the intra-pancake joint, and additional insulation).
New gantry crane
2017-09-19 - The main structure of the new gantry crane has been assembled outside of the building and is now positioned outside of the north door.
A tailor's workshop?
2017-09-18 - Immaculate fabric, precise measurements and a large pair of scissors: the winding table in the Poloidal Field Coils Winding Facility could be mistaken these days for a high-tech tailor's workshop. Here, technicians are manually inserting fiberglass material between the turns of conductor.
An automatic operation
2017-09-18 - The tape dispenser is in motion, automatically wrapping the conductor with five layers of insulating material.
Extra handling
2017-09-17 - A large gantry crane is being assembled outside the north entrance to the Poloidal Field Winding Facility, which will soon be moved inside.
The spreader beam enters action
2017-08-31 - Here's how the double pancakes are transported from one station to another: the 40-tonne circular spreader beam.
Starting on a second pancake
2017-08-22 - The first few metres of superconductor for the second double pancake winding are visible on the table. Photo: °ÄÃÅÁùºÏ²Ê¸ßÊÖ Organization/EJF Riche
Floor rails installed
2017-08-22 - In the last third of the building, rails have now been installed on the floor to accommodate the new gantry crane. Photo: °ÄÃÅÁùºÏ²Ê¸ßÊÖ Organization/EJF Riche
Assembly of gantry crane
2017-08-21 - Just outside of the Poloidal Field Coils Winding Facility teams are assembling a gantry crane, which will be installed at the end of the manufacturing line. Photo: °ÄÃÅÁùºÏ²Ê¸ßÊÖ Organization/EJF Riche
More equipment
2017-08-17 - The "pieces" of the gantry crane are starting to arrive. The circular station in the background is where the entire coil assembly (eight stacked double pancakes in the case of PF5) will undergo impregnation—a process that "hardens" the assembly and insulates it electrically.
Footings
2017-08-17 - Large tracks have been laid for the gantry crane.
Getting a real idea of fabrication
2017-07-04 - On display for visitors in the European winding facility are some of the critical elements of the fabrication process: superconducting strand, cable, conductor, and helium inlet joints.
Several projects at once
2017-07-03 - While the first double pancake for poloidal field coil #5 is in the last stages of winding (out of frame, far left), the copper dummy winding on the staging table (centre) is being prepped for impregnation.
A meticulous process
2017-06-20 - In a vast manufacturing facility on the °ÄÃÅÁùºÏ²Ê¸ßÊÖ site, the poloidal field coil team is starting on the second layer of production double pancake number one.
Taking it in steps
2017-06-14 - The qualification winding, made of copper conductor, rests on a staging table while preparations are made for impregnation.
The good old calliper
2017-04-27 - Creating the first double-layer winding pack for poloidal field coil #5 is a highly sophisticated technological operation. But when it comes to measurements, nothing beats the good old calliper.
Fabrication begins!
2017-04-27 - After the validation of qualification activities, Europe begins the winding of coil #5 in April in the on-site Poloidal Field Coils Winding Facility.
Like an Egyptian mummy
2017-04-27 - The steel-jacketed conductor is wrapped with several layers of tight-fitting insulating tape, and then enveloped in a special fabric. This technician from the European firm CNIM (contractor to the European Domestic Agency) carefully checks the conformity of the tight gaps between conductor turns.
Refilling the tape dispenser
2017-04-27 - Operators can wind approximately 20 metres of conductor before it's time to renew the taping heads and replenish the sandblasting cleaning equipment with fresh sand.
Get equipped
2017-04-27 - Lab coats and overshoes are mandatory in the "clean room" where operators have started on the first conductor turn for poloidal field coil #5 (PF5).
Under watchful eyes
2017-04-27 - Winding activities are closely monitored by the European Domestic Agency and specialists from the engineering integrator ASG Superconductors. Note the tape dispenser spinning in the background.
Off and running
2017-04-12 - Technicians from the European contractor CNIM supervise the first stage of operations: the uncoiling and straightening of the spooled niobium-titanium conductor.
It starts here
2017-04-12 - The first conductor length enters the straightening equipment at the start of the winding table. Conductor is fed in from two points at once in a process known as "double-hand winding."
Impregnating and bonding
2017-01-12 - Before they are stacked to form a coil, each double pancake must be impregnated with epoxy resin under vacuum pressure to electrically insulate and bond each double pancake into a rigid assembly. Two impregnation stations are under construction now.
First station
2017-01-12 - The 20-tonne conductor spools delivered by China are installed by overhead crane (with the assistance of the star-shaped tool at right) on the tower situated at left. From there, the conductor is straightened, cleaned and then bent again on the winding table to match the geometry of the future coil.
Last impregnation
2017-01-12 - In the last production phase, double pancakes are stacked and connected electrically. The several-hundred-tonne winding pack is transferred to the final station for resin impregnation of the whole assembly.
Winding and wrapping
2017-01-12 - As the conductor enters the winding table, a device comparable to a complex, high-tech scotch tape dispenser tightly wraps it in layers of insulating fiberglass tape. The carefully synchronized winding and wrapping operations result in a "double pancake" made of several "turns" of insulated coil.
Workshop tooling progressing
2017-01-12 - The Poloidal Field Winding Facility as photographed in January 2017. Tooling stations are now framed out from one end of the building to the other.
Production in stages
2016-11-24 - Following the winding stage, technicians verify the glass-fibre tape that is used to electrically insulate the turns of conductor. Photo: F4E
"Dummy" winding takes shape
2016-11-23 - The first complete double pancake layer, made from "dummy" conductor in copper, reflects the dimensions of °ÄÃÅÁùºÏ²Ê¸ßÊÖ's fifth poloidal field coil (PF5).
Precision tools
2016-11-09 - Rotating tape heads enter into action as the conductor joins the tooling table to be "turned" into the precise dimensions required for each coil. Photo: F4E
During a visit
2016-10-19 - From a visitor gallery in the middle of the 257-metre-long building, we look south toward the impregnation and winding stations.
First pre-dummy qualification winding
2016-10-06 - As a qualification activity for tooling and processes, European contractors have produced a pre-dummy winding of eight turns of conductor (pictured, in white). Photo: F4E
Resin station
2016-10-06 - Completed double pancakes will be transferred by overhead crane to this impregnation station, where the components will be "hardened" with epoxy resin. In the blue stand at left is the resin tank. Photo: F4E
Two hands simultaneously
2016-10-06 - The blue winding station is served by two ("double hand") spools of conductor. Operators will produce 30 double pancakes to constitute the building blocks for the four poloidal field coils produced on site (PF2, PF3, PF4, PF5). Photo: F4E
One small step practiced
2016-09-16 - A European contractor practices one important stage of the manufacturing process: creating the inlets in the conductors for helium. An average of eight helium inlets will be needed per coil.
Ready for the handling operations
2016-08-30 - The overhead crane and its spreader beam will be capable of lifting the individual windings and transporting them from one station to the next with a minimum of tilt. For the handling of the final assemblies, however, a gantry crane will be necessary.
Despooling
2016-08-30 - In the winding stage of fabrication, the conductor is uncoiled from the spools and straightened before passing through cleaning and sandblasting machines that prepare its surface to receive several layers of glass-fibre insulating tape.
Work station 2
2016-08-30 - Late August, contractors install the impregnation table in the Poloidal Field Coils Winding Facility.
Visiting the first on-site manufacturing activities
2016-08-12 - In July, a delegation from Japan looks out over the first on-site manufacturing activities for the °ÄÃÅÁùºÏ²Ê¸ßÊÖ poloidal field magnet coils.
Step-by-step process
2016-07-27 - Coil manufacturing is carried out in a series of steps. The double pancakes are first wound and then prepared for treatment with epoxy resin in the first clean area (foreground) and then transported to the impregnation station that is just visible on the far right of the photo. Photo: F4E
Spools awaiting
2016-07-27 - These spools of conductor delivered by China will be installed on the tower-like "de-spooler" (in yellow) to be straightened before winding. Photo: F4E
Impregnation tooling installed
2016-07-19 - In the second clean zone of the facility, an impregnation table has been installed. Here, the coiled "double pancakes" produced during the winding stage are impregnated with epoxy resin in order to provide rigidity and electrical insulation.
Tooling progresses
2016-07-19 - The winding zone (near) and impregnation zone (far) are both visible in this photo of the Poloidal Field Coils Winding Facility.
Four girders await
2016-05-18 - The four overhead crane girders have been stored in the Poloidal Field Coil Winding Facility until they can be assembled with gear motors, braces, electrical equipment and the like. In June, they will be moved to the Assembly Hall for installation.
Temporary shelter
2016-03-25 - The mammoth assembly crane beams will be stored in the Poloidal Field Coils Winding Facility until their installation in the Assembly Building in June.
Sophisticated tooling
2016-03-03 - A detail of some of the winding tooling now installed in the building. Photo: F4E
Crane overhead
2016-03-03 - Once wound, the double pancakes will be transported by overhead crane to the next station for impregnation with epoxy resin. Photo: F4E
Storage facility advances
2016-02-16 - Part of the parking lot on the south side of the facility has now been given over to storage. Photo: ENGAGE
17 m in diametre
2016-02-16 - This support structure will be used after the winding operations, as the completed double pancakes are prepared for the impregnation phase. It allows us to visualize the size of the first two coils to be wound (PF#2 and PF#5)—approximately 17 m in diameter. Photo: ENGAGE
The winding area
2016-02-16 - The winding tooling is colour-coded: yellow for the moving parts and blue for the static ones. Photo: ENGAGE
A small vacuum chamber
2016-02-04 - The spools of conductor undergo helium tests before the material is introduced on the winding lines. Here, we see the top part of the vacuum chamber that is used for the testing.
Extra space
2016-02-04 - A small extension is going up on the south side of the Poloidal Field Coils Winding Facility. It will be used for storage.
Tooling for poloidal magnets 2 and 5
2016-01-13 - Four poloidal field coils will be manufactured in the on-site winding facility (coils 2, 3, 4, and 5). Operations will begin at the double winding station on the south side of the building. Here, spools of niobium-titanium (NbTi) superconductor will be wound into flat, spiralled coils called "double pancakes." Up to eight double pancakes will be assembled into each magnet coil.
From the visitor gallery
2016-01-08 - Tooling installation is progressing in the Poloidal Field Coils Winding Facility. Visitors have a great view of work underway from the second-floor gallery that has been created on the southern side of the building. Photo: Christophe Roux, IRFM
Room for two tables
2015-11-13 - Two winding tables will operate side by side to produce flat, spiralled coils called "double pancakes." In this building, up to eight double pancakes will be stacked to form the final coils.
First tooling equipment
2015-11-13 - Workers from the European contractor SEA ALP (Turin, Italy) are currently installing the first poloidal field coil winding tooling table in the on-site Poloidal Field Coils Winding Facility.
Two clean areas
2015-09-25 - The clean area on the south side of the building will host two winding tables, where lengths of niobium-titanium conductor will be fed from two spools simultaneously ("two-in-hand" winding), insulated, and wound into double pancakes. Dummy conductor for tooling qualification is stored in the crates, at left.
Big yellow hands
2015-09-25 - Overhead cranes will travel the length of the 257-metre Poloidal Field Coils facility to transport the double pancake windings from station to station. The complete process, from winding to finished coil, will take approximately two years.
Manufacturing preparations begin
2015-07-21 - In July, a clean area is established around the area of the Poloidal Field Coils Winding Facility that will host the winding tooling. The first tooling elements also arrived by truck this month.
2015-07-21 -
