New control system improves target cooling on TS2
08 Sep 2026 - Stephanie Richardson
The ISIS Target Controls group, working with colleagues from Target Operations, Target Design, Electrical Systems and the Main Control Room, has successfully completed a major upgrade to the Target Station 2 water cooling control system. The new system introduces variable-speed water flow and a new target trip system, which will improve safety, reliability and sustainability.
When the accelerated proton beam, travelling at 84% of the speed of light, strikes the tungsten target at the heart of Target Station 2 (TS2), neutrons aren’t the only product of the impact. Spallation – the process of generating neutrons by impacting the target with high-energy protons – also produces large amounts of heat.
To ensure safe and reliable operation, this excess heat must be continuously removed by a flow of cooling water. However, the previous water cooling control system, installed when TS2 was commissioned nearly 20 years ago, had reached the end of its operational life.
During a month-long programme of work, ISIS Target Controls group removed the obsolete system and installed a modern replacement. The upgrade required two and a half years of careful planning and coordination to ensure the new controls could be installed, tested and commissioned during the 2026 summer shutdown.
A key feature of the new system is the ability to vary the water flow rate. Previously, the pumps operated at full speed whenever the system was on. The upgraded controls allow the speed of the water to be adjusted to match operational requirements, providing efficient cooling while reducing energy consumption. The ability to optimise water flow and slow the speed of the water also reduces wear on target components, helping to extend their lifetime.
Michael Julian (Main Control Room) and Thomas Eagles (Target Controls) stand in front of the old control panels discussing the plans for the upgrade.
Alex Baker (Target Controls) wiring the new PLC control panel. The team had to systematically replace hundreds of cables during the upgrade.
Adam Burridge (Target Controls) testing the new Human-Machine Interface during commissioning.
The new instrumentation installed in Target Station 2.
The upgrade also introduces several new operational and safety features. The control system continuously monitors key parameters including water temperature, pressure and flow rate using sensors. Previously, if one of these sensors failed, or measurements moved outside predefined limits, the beam would be automatically shut off.
In the new system, sensor readings are assessed collectively to determine if there is an issue, and the beam shuts off when multiple parameters indicate a cooling circuit fault. If most sensors show that the system is operating normally, the Target Controls team are alerted to any anomalous reading, allowing them to examine and resolve potential issues. This means that faults can be investigated while minimising unnecessary downtime.
“The upgrade of the TS2 target cooling system has taken many years of planning, with only a small window to complete the work,” says Alex Baker, Lead Engineer on the project. “Installation and commissioning involved cooperation across multiple teams. I am really proud of the work that we’ve completed and the way in which it was executed by all those involved. It’s a testament to ‘Teamwork makes the beam work’ and the ISIS ethos.”
Installation and commissioning involved cooperation across multiple teams. I am really proud of the work that we’ve completed and the way in which it was executed by all those involved.
Alex Baker, Senior Engineer
