Accelerator
Drift Tube Linac (DTL)
DTL tank 1 is installed and vacuum-tested. Connection of couplers is ongoing.
The DTL1 Faraday Cup shielding is in place.
The temporary shielding wall separating the normal conducting linac from the superconducting linac, has been rebuilt in-situ. The door plug is still to be mounted once the tunnel is ready to be closed with the Personnel Safety System (PSS) again.
Cryomodule testing
The first serial-produced medium beta cryomodule has been successfully tested inside a test stand bunker. All four cavities were cooled down to 2 Kelvin (-271 degrees Celsius) with full radio-frequency (RF) power, and with closed loop operation confirmed on all systems.
The second cryomodule is now being installed inside the bunker, with testing foreseen to take roughly one month. Three more cryomodules are expected from from French In-Kind parter, CEA, within the next month.
The third cryomodule in line for the spoke section has been fully tested at the Freia lab test stand in Uppsala, and will be delivered to ESS shortly.
Linac Warm Unit (LWU)
Three of the LWUs that are placed in the Accelerator tunnel in between the cryomodules have been aligned to their permanent position. LWUs are standing in-between cryomodules in the superconducting linac.
Normal Conducting Gallery
High power tests of the DTL klystrons and modulators are ongoing. Tests for the DTL1 system are completed.
RF power station powering the spoke section
As the testing for the first RF power station for the spoke section was successfully completed, low power tests of the second RF power station have now commenced in cell 120.
Target
Active Cell
Installation of the upper intrabay door is in progress. This includes a frame installation attached to the ceiling of the cell, a shotbolt lift beam installation both sides of the cell in the technical gallery and remote handling rope guides along the in-cell crane rails, connected to a drive assembly, which is installed on the other side of the shielding wall in Transport Hall.
The intrabay doors form part of the barrier between the process cell and maintenance cell of the ESS Active Cell facility. The upper intrabay door can be opened to allow passage of the Active Cells crane. The lower intrabay door will open to allow passage of suspended loads from the crane.
Both doors will be remote handled from the control room, but manual recovery via the confinement penetrations to the technical galleries will be possible in case of system failure.
Installation of a fire suppression system for the Active Cells' process cell is ongoing both in-cell and along the Technical Gallery walls.
Floor valves
Installation of the floor valves continues on the high bay to Active Cell openings. Completion is expected soon with a site acceptance test planned for mid-October.
Target roof
Cladding of the entire Target cantilever roof is planned for completion by the end of October.
On the north and south sides along Experimental Halls 1 and 2 cladding is completed.
The west side - above the D08 laboratory, Target Entrance and Transport Hall - is in progress with also special panels being mounted in curved areas and in joints. Shortly, roof cladding will follow on the east side, above the Accelerator to Target (A2T) building and D04 laboratory.
Experimental Halls & Labs
Beamline Gallery
On September 13, the second part of the Beamline Gallery was handed over to ESS. Installation of lower shielding blocks for beamlines for CSPEC and BIFROST is in progress.
Experimental Halls 1 and 2
Touch-up painting and handrails is in the final stages for the steel bridge gangways along the walls of the two short instrument halls.
Reinforcement of the bunker runway is ongoing on the north side of the Monolith, and will shortly follow on the south side. Bunker cranes will be the last installation by construction partner Skanska. The cranes are planned to be operational by the end of this year.
Laboratories
In lab buildings D04 and D08 all site acceptance tests of installed systems are completed, with handover inspections to follow. ESS will have access to the ground floor of lab D08 to start the in-ceiling installations for a Radioactive Materials Lab (RML).
Glove boxes, already delivered and commissioned in the E04 lab and delivered from the University of Tartu as an Estonian in-kind contribution to ESS, will be moved here.
Skanska works - towards the end of construction
In the Target building, Skanska are in the last stages of internal finishes, in view of the sectional handover inspections in October.
Outside the Target Entrance building, ground concrete connecting to the Campus plaza is completed, expecting to equip remaining surfaces with asphalt mid-October.
Completion of external areas continues, including seed planting.
Final handover to ESS of all remaining areas and buildings is scheduled for 21 December 2021.
