Normal Conducting Linac - Full current beam to DTL1!
Wednesday 13 July was the last day of beam commissioning for a while, as the ESS Accelerator Operations team completed the phase of beam commissioning with the objective to send a probe beam to the Faraday cup of the first Drift Tube Linac. This was achieved in early June. More recently, the team managed to transport a full current beam through the DTL, which is a significant milestone.
Next up is the installation of Drift Tube Linacs 2-4, increasing the length of Accelerator to be commissioned to over 40 metres!
Cryogenics & Cryomodules
Leak testing of the Cryogenic Distribution System (CDS) in the Superconducting Linac is ongoing. This will be followed by commissioning of the entire CDS from coldbox to end box and back. A leak tight CDS is a prerequisite to begin the installation of cryomodules in the tunnel.
The trial installation of the first cryomodule in the superconducting linac, connecting it to the helium collector system and the CDS, was successfully completed.
During the autumn, the remaining spoke cryomodules will be delivered from the test stand at the Freia Lab in Uppsala. 13 double-cavity modules are to be installed in the spoke section of the linac.
The testing of medium and high beta cryomodules will continue in the on-site Test Stand. Right now, we have four fully tested medium beta cryomodules in storage and ready for installation, with another unit currently subject to cooldown and RF tests inside the test bunker. Two high beta cryomodules have been delivered and are stored in one of the RF stubs.
Testing power sources in the Gallery
Power tests involving medium beta klystrons and Spoke power stations continue on the Gallery-side. High power tests are completed for the DTL2 power sources, and continue for the remaining units in the Normal Conducting Gallery needed for the RF conditioning of DTL 2-4.
Monolith inner shielding
The first batch of inner shielding blocks are in place inside the Monolith vessel. Deliveries and subsequent installation within the cleanroom confinement covering the Monolith area will resume after the summer break.
After the vacation period, the drive unit will be reassembled on the Target wheel shaft for handling and rotation tests to start in the Mock-Up and Test Stand (MUTS). All equipment to be installed inside the Monolith vessel will be fitted and pre-tested in the MUTS before installation.
A Shaft Cutting Station is in place inside the process cell, with Site Acceptance Tests ongoing.
The cryo transfer line connecting the coldbox hall to the jumper spoolbox in the hydrogen room on the top floor of the Accelerator to Target (A2T) building will be pressurised for leak tests. Commissioning of the Cryogenic Moderator System is under way.
Light Shutter System (LSS) frames are in place in the north and west sector of the bunker. Installations will continue in August in the south and east sectors. LSS frames sit in a 6-metre radius from the centre of the Monolith, and provide the interface between the port tubes and the neutron guide system.
Installation of inserts, port plugs and Neutron Beam Windows in the north sector of the bunker is expected to start in September.
In-bunker electrical infrastructure as well as cooling pipes to the north and west sectors will also commence.
Three Neutron Beam Port Inserts (NBPI) were delivered to ESS this spring, with optics assembled for ODIN and LOKI and neutron guide integration for the Test Beamline next. Another five NBPIs are expected for delivery this summer, for instruments DREAM, FREIA, ESTIA, VESPA and SKADI.
The in-bunker chopper for ESTIA, delivered from in-kind partner PSI in Switzerland, was assembled including fitting of spindle and disc. Rotation tests have been performed.
ESTIA in-bunker installations, which include putting the bunker wall feedthrough in place, will start this autumn. Final installation of the ESTIA Selene guide 1 and the start of installation for Selene guide 2 will follow.
The experimental cave base slab construction was completed, with precast elevated structure foreseen to start in October.
The neutron guide as well as base structures for three choppers inside the bunker and one on the outside have been installed. The upper part will follow this autumn.
Fitting of a detector support frame and sample vessel support is ongoing inside the instrument cave. Installation of the sample vessel and vacuum tubes will be next.
All instrument components from UK in-kind partner STFC/ISIS are anticipated for delivery before the end of this year. Fitting of the cave and sample area shielding walls will take place after the summer.
A support structure for the BEER neutron guide is in place in the Beamline Gallery. Neutron guide optics assembly is ongoing. This part of the neutron guide totals 64,5 metres out of a total 158 metres from Target to sample position.
Construction of the ESS Test Beamline, occupying beamline W11 in the west sector, will start this autumn. It will be the first to receive neutrons at ESS once we have Beam on Target, and will be used to verify, measure and characterise the beam.