Drift Tube Linac (DTL)
DTL 1 is in its final position in the tunnel, with installation ongoing. Final alignment, as well as cooling and vacuum connections, are in progress. The Faraday Cup and associated shielding are being delivered and will be installed at the end of DTL1.
A small team from Italian in-kind partner, INFN, is working on the other DTL tanks inside the DTL workshop in G02. The modules for DTL tank 3 are fully tuned and tested, ready for connection.
Getting ready for beam commissioning
Preparations are ongoing to run beam from the Ion Source up to the Medium Energy Beam Transfer (MEBT) Faraday Cup in October. A Safety Readiness Review will be held shortly.
The MEBT section, which is an in-kind contribution from ESS Bilbao, is subject to alignment, magnet power tests and chopper tests, to be completed before commissioning.
The test campaign of all Radio-Frequency power sources is progressing in the normal conducting part of the Gallery. Low power tests are mainly completed for the DTL klystrons, and are now followed by high power RF tests, with power fed from the modulators.
The first RF power station in spoke cell 120 has successfully completed its first test cycle at full power.
Spoke valve boxes
The last three remaining valve boxes and the end box for the spoke section of the linac have been delivered and placed in the tunnel. Header units are still to come. These valve boxes will be connected to 13 spoke cryomodules, which are currently undergoing testing in the Freia test stand lab in Uppsala. Two of those modules have already been fully tested and shipped to ESS.
Tests of the first medium beta cryomodule in the test stand 2 bunker are ongoing. Low level RF in all cavities at 2 Kelvin has been achieved, and the power is now gradually being ramped up.
The two remaining bottom plates for the target monolith base plate have been positioned around the monolith vacuum vessel. These will be aligned and bolted in place. The welding of 39 neutron beam port tubes to the vessel will start in October.
The installation of floor valves, covering the openings from high bay to the process and maintenance cells, continues.
The lower intrabay door, separating the two cells of the Active Cell, has been mounted, final fixtures to be installed. This will be followed by the upper intrabay door.
Cantilever roof cladding above Transport Hall, with rows of panels being mounted to the cantilever roof skeleton, continues. In total 2,952 panels, each holding three aluminium lamellae, will be bolted to the protruding roof structure around the Target buildings and short instrument halls. About half of these panels are already in place. Panels are assembled on site, and come in 12 different varieties to fit the existing steel structure. Special, customised panels are needed in joints and particularly curved areas.
Panel installation is also in progress in the area between Target Entrance and D08 lab.
Façade cladding is nearing completion on the A2T side of the building, with roof cladding to follow in this area in the autumn.
During September, works on site will start for the instrument LoKI.
A cave and control hutch will be built in the east part of Experimental Hall 2. The detector vessel, already delivered to ESS this summer, is currently stored in the northwest end of the hall. The installation of base plates and plinths will mark the beginning of on-site activities for the LoKI team.
Beamline Gallery, part 2
Fire painting of columns has been performed, with some touch-up works still ongoing.
Handover of this building to ESS takes place on 13 September.
Towards completion of civil construction project
Final handover, from construction partner Skanska to ESS, of all remaining buildings and landscaped areas will take place on 21 December 2021.
Right now, final Site Acceptance Tests (SAT3) are ongoing in the Target Building and two adjacent short instrument halls. These are scheduled for completion by the end of October, and will be followed by handover inspections.
Last week, asphalt was poured for the external areas to the D08 lab and substation D06 in the Target Station external areas.
The reinforced slab for the remaining ground concrete outside Target Entrance is ready for concrete.
Landscaping completion works continue around site.