The ESS accelerator operations team are preparing to start conditioning of the Radio-Frequency Quadrupole (RFQ) early June. This involves sending high power radio-frequency (RF) power to the cavities of the RFQ. Beam commissioning, i.e. sending beams of protons from the ion source to the Medium Energy Beam Transport (MEBT) section, is planned to follow from August.
The first spoke RF cell in the klystron gallery is fully installed and two RF power stations have been successfully tested and are ready for installation.
Installation of a total of 13 valve boxes are progressing in the spoke section of the linac, with three units in place and another three delivered and ready to install. Valve boxes are part of the Cryogenic Distribution System (CDS) for the superconductive linac. Once the entire CDS has been cooled down and passed all tests later this year, installation of cryomodules can commence in the tunnel.
The first serial-produced medium beta elliptical cryomodule has been connected to the infrastructure inside a test stand bunker. Warm RF power tests will start shortly, followed by cooling of the cryomodule cavities to 2K (-271 degrees Celsius). The second medium beta cryomodule will arrive on site in mid-June.
Three medium beta modulators are in place in RF cells in the klystron gallery, with the fourth currently subject to tests with a dummy load. Low power testing for the klystrons installed in the first medium beta cell is ongoing.
Installation of three 20-tonne concrete shielding doors for the triangular rooms between the utility and monolith buildings is planned for the coming week, starting with the installation of rails, grouted to the floor and fixed with anchor bolts. The doors will open and close via a mechanical drive assembly using a hand wheel to operate.
Also subject to delivery and installation start before the end of this month, are the cutting station for the process cell and waste transfer system for the target active cell facility, as part of the UK in-kind contribution to ESS, via UKAEA and RACE.
Mounting of aluminium lamellae and façade cladding continues for the target building.
Installation of a neutron shielding bunker around the monolith footprint is progressing. The blue concrete blocks for the north sector bunker walls have started to arrive on site for installation to begin inside experimental hall 3 shortly.
In experimental hall 3, the base structure and spectrometer vacuum tank was successfully lifted inside the BIFROST cave this week. Assembly, alignment and tests are in progress. Installation of a local crane will follow early June.
Construction of a control hutch next to the NMX instrument cave is in progress.
Vacuum tests to the neutron guide housing for the CSPEC beamline are in progress inside the beamline gallery building.
Floor treatments are completed for part 2 of this building and finishing works are now underway for the entrance area and beamline wall to experimental hall 2. ESS will gain parallel access from construction partner Skanska at the end of May, according to plan.