Target Station 1 (TS1) has run for over 30 years without significant maintenance or development work. The TS1 project seeks to upgrade key elements of the target station, with the actual work likely to take place around 2020.
This spring saw a huge milestone in the TS1 Project as the new target was assembled for the first time. Its modular design with ten individual plates of tantalum-clad tungsten, which are electron beam welded together, took over a year to design and another year to build. The target won’t be installed until next year, during the upcoming long shutdown period, but there is no rest for the target build team – they have already started building a duplicate target to have on standby in case the service life of the first target is less than expected.
Not only is the target itself different, but the surrounding assembly also needs to be updated, as do the associated tooling and jigs. To ensure everything fits together as it is supposed to they have also made a 3-D printed model of the target, an aluminium machining test piece, and a full-scale welded stack of stainless steel plates. This full-scale model, along with a replica target vessel, is likely to form part of a mock-up used by the remote handling team.
The design and build of this target are extremely specialised and unique: it’s only recently that ISIS began making targets in-house, and the building that houses the assembly project was only opened in 2018.
After completion of the manufacture of the target, it has undergone a range of testing. This has included using the target manufacture group’s microscope and ultrasound facilities to double check the diffusion bond between the tungsten and tantalum in each of the target plates, ensuring the heat is extracted by the cooling water.