The lower part of the vacuum vessel is in place on the Monolith puck, the lid is on and 'windows' have been covered to minimise dusting and contamination inside. The ESS Survey and Alignment team have performed measurements, and shortly final adjustment of this piece will be made before the medium vessel part is lowered on top.
Cantilever roof installation, part of the ESS 'sombrero', has started at the back of the Target building, above the Transport Hall and Target Entrance building.
Installation of walkways is in progress on high bay level. The remaining epoxy floor on high bay level will be done early 2021, when the entire high bay, including Accelerator to Target (A2T )and Transport Hall, is weathertight. In A2T, interior works with internal fire-protection walls are starting up.
The construction of the ESS neutron shielding bunker is ongoing inside Experimental Hall 2 - this involves the north and the west sectors, with the west sector already equipped with steel framework. The first concrete blocks are expected to arrive on site within short, to be mounted on the steel structure.
The purpose of the bunker is to provide shielding for the main source of radiation, target systems, the monolith as well as the first several meters of instruments hardware and beam guides. And yes - it will be ESS blue!
Works inside the Drift Tube Linac (DTL) workshop continues, at the same time as cable pulling for the DTL section in the Linac is substantially completed.
Preparations are ongoing to conduct radio frequency (RF) power tests with the cryomodule prototype inside the bunker in Test Stand 2 inside the Gallery building. Once this is completed, tests with serial-produced cryomodules will commence, the first of them currently waiting in the preparation area outside the bunker.
All modulators for the Normal Conducting Linac (NCL) and medium beta section have been delivered, with the 3 modulators in the Normal Conducting Gallery already placed in their permanent position. Tests with medium beta modulators are in progress inside Test Stand 3, with the first one set to move to its permanent home in the first medium beta RF cell shortly. In Test Stand 3 tests of Spoke RF stations, powering the Spoke section of the Linac, are also ongoing. The Spoke section will be powered by 26 tetrode based RF power amplifiers, which are lower-power units containing both the modulator and tetrodes.
Tests and commissioning of the Personnel Safety Systems continue – this includes the Material and Personnel Access Stations in the Front End Building and the fencing by the Ion Source and temporary shielding wall, separating the NCL and the Spoke sections of the tunnel.
Piping works, rack fit-outs, cable raceways and cable pulling are ongoing activities in the Accelerator buildings, as always.