Accelerator
Beam is on!
Beam commissioning from the Ion Source to Drift Tube Linac 4 (DTL4) in the Normal Conducting Linac has been ongoing since the middle of April. The power going through DTL4 is now being increasingly ramped up for the last two weeks of commissioning for the first 42 metres of the Accelerator. A 40mA current beam was recently recorded through the four Drift Tube Linac tanks.
Cryogenics
Following a string of upgrades and system modifications, a second cooldown of the cryogenic distribution system to the Accelerator started mid-May. Recently, the teams involved (Superconducting RF group, Cryogenics and Integrated Control Systems) have successfully reached the goal temperature of 2 degrees Kelvin (-271 degrees Celsius) in both cryomodules installed in the tunnel.
Low-level power was sent from an RF cell in the gallery, through the waveguide system, to the cavity of the medium beta cryomodule installed in the tunnel. This was a first-time measurement of a direct field in a fully installed cryomodule cooled to 2K at ESS.
The 12 double-cavity spoke cryomodules are under preparation for installation in an on-site workshop. Serial installation of cryomodules, starting with the spoke model, is foreseen to begin early August.
Cooling substation
Two new heat exchangers have been delivered to one of the cooling substations in the Klystron Gallery. These are part of the extended water cooling system that is being installed to increase the cooling capacity for the ESS Accelerator.
Target
Monolith
The installation of all major shielding blocks for the Target Monolith inner shielding is completed. Read more here.
During the summer, vacuum tests of the Monolith - including the volume of the entire vessel up to the neutron beam windows of the neutron beam port inserts and plugs – will be subject to vacuum leak tests.
Meanwhile in the high bay welding workshop, the cooled shielding blocks that are to be installed on top of the Target Wheel and Moderator assemblies are being equipped with pipes.
Neutron Beam Port Inserts and Plugs
The installation of inserts and plugs continue for the 42 port tubes surrounding the Target. The 16 inserts contain the first few metres of neutron guides for the 15 instruments and the Test Beamline. Each insert or plug is equipped with a neutron beam window which is sealed in several steps. Vacuum tests and final alignment of each insert follow. The purpose of the neutron beam windows is to seal the Monolith atmosphere from the instrument beamlines. For the inserts, they have an internal window made of aluminium, through which the neutrons can pass.
Light Shutter System
The first installation of a Light Shutter System took place at the beam port designated for instrument FREIA. The system was installed from the Monolith basement, with the components being pulled up to the neutron guide level (i.e. ground level) using chains.
The Light Shutter System plays a crucial role in the neutron beam extraction. It comprises a bridge beam guide, a gamma blocker, and an actuator. The bridge beam guide is designed to accommodate the first 0.5 metres of the beam guide assembly for each active instrument port. The Gamma shutter is responsible for automatically closing in the event of system failure, and its operation will be controlled by the ESS integrated control system. Shutters will also be closed during shutdown periods. The actuator serves as a device for positioning the system components accurately.
15 more installations will follow, one for each active instrument port.
Moderator
The Moderator/Reflector plug is in the temporary cleanroom next to the Mock-Up and Test Stand in the Transport Hall. The component has been cleaned on the outside and is now pending cleaning of the impurities of the cooling loops on the inside as well as the improvement works for imperfect welds.
Active Cells
The Telbot manipulator, a remote handling device with two robotic arms, is in place in the process cell of the Active Cells. It will be installed onto a test stand, for the ESS Remote Handling group to do training on. This is a UK in-kind delivery from UKAEA.
Instruments
LOKI
The collimation vessel has been positioned in-between the bunker wall chopper and the sample position area of the cave. False floors are getting in place in the sample area, with supporting legs mounted.
The installation of the out-of-bunker chopper was also performed.
Next up for LOKI: Installation of internal components inside the collimation vessel, cable containments and handrail installation on top of the cave.
ODIN
The remaining precast concrete blocks for the ODIN cave walls have been lifted in place, including the blocks for the inner wall, separating the sample position from the detector area of the cave. A few blocks will be exchanged, due to quality issues and the roof element installation will follow in the autumn.
ESTIA
Cave construction started for the ESTIA instrument cave. Precast walls have been erected and internal floors cast.
NMX
Neutron guide supports in place along the NMX beamline. The installation of the neutron guide system will follow after the summer holidays.
Waste Treatment Facility
Two overhead cranes have been delivered and are ready for installation. One will be mounted in the central hall (20 t) and one in the hot works room (6,3 t).
Works in the H09 waste treatment facility will ramp up during the autumn with piping, shielding and equipment installation starting.
