Drift Tube Linac tank 4 (DTL 4) has been transported to its permanent place in the Normal Conducting Linac. This is the second out of five DTLs getting in place, after preparations in an on-site workshop. Two more DTLs (DTL 2 and 3) will follow during the autumn, with the next stage of Beam Commissioning, from Ion Source to DTL4 Faraday cup foreseen to early 2023.
In-kind partner INFN - The National Institute of Nuclear Physics of Italy - is responsible for the Drift Tube Linac section of the ESS Accelerator.
The Drift Tube Linac consists of five 8-metre-long tanks and make up the last structure of the Normal Conducting Linac (NCL), also known as the warm Linac (operating at room temperature). The purpose of the DTL is to increase the energy of the beam from 3.62 MeV to 90 MeV and hence accelerate the beam, before it reaches the superconductive part of the Linac. Klystrons, placed on the Gallery side, feeds the DTLs with radio-frequency (RF) power, via waveguides through stubs.
Target wheel shaft assembly
During the past week, engineers from Thune Eureka – a sub-contractor to in-kind partner ESS Bilbao in Spain - have been on the ESS site to adjust the Target wheel shaft for assembly onto the wheel inside the Target Mock-up and Test Stand (MUTS). Additional seals and gaskets to the connection between the wheel and the shaft made it possible to lower the 3,7-tonnes shaft into position.
The assembly will now be evaluated before the Target Installation team can mount the drive unit on top, with handling and rotation tests following. The Target Monitoring Plug and Moderator & Reflector Plug, delivered from German in-kind partner Jülich, will also be fitted and tested inside the MUTS.
Installations for instruments
A bandwidth chopper, installed midway of the BIFROST neutron beam guide, is subject to commissioning activities. Choppers are devices equipped with a rotating disc with slits, letting through only the desired range of neutrons to the instrument's sample position.
Inside the BIFROST scientific cave, false floors for cabling are under installation.
The under-tank raceway installation continues for LOKI, at the same time as shielding walls are prepared for mounting around the detector tank. Installations on the control cabin roof will follow.
The ESTIA Selene guide 2 is in place, with vacuum tests and commissioning coming up.