Long Shutdown Updates
01 Mar 2022



Stay up to date with the latest updates from the engineering projects happening during the ISIS long shutdown.




7 January

It's the new year and the first new piece of kit has been installed into the target assembly area. The new crane was lifted into place, and can take up to three times more weight than the one previously present in the area. This means that the team will be able to move more equipment without the need to remove the roof and use the larger crane in the TS1 hall. ​

ISIS staff using the large crane to lift the new craneThe new crane being lifted into place

17 December

The new TS1 hydrogen moderator has arrived, as the last piece of the puz​zle for the TS1 project TRaM.

​​Dan Coates and Harry Sullivan​ working on the new hydrogen moderator

7 December

​First beam accelerated through the new linac tank 4! After a journey of almost 10 years, taking us from initial design work, through manufacture and testing and ultimately ​installation onto ISIS, the team were elated to see the tank successfully accelerate a beam. Not only did it accelerate – we were rewarded with a 94% transmission efficiency on the first attempt!​

The beam current monitors before and after tank IV (top two traces), showing the beam pulse passing throughMCR Linac efficiency screen

2 December

To prepare for work on the collimator just after the muon producing target in the extracted proton beamline, ISIS engineers have been using a drone to map the radiation levels​ in the area. 

Drone with EPD in flightview of the collimator set up in the dark

23 November

To prepare for installation of the new target assembly in TS1, the roof lintels were removed and replaced with a temporary roof​. 


10 November

The new synchrotron room beam dump diagnostics assembly has been installed. 
The new synchrotron room beam dump diagnostics assembly

5 November - Hissing Sid the hovercraft

When the dipole magnets in the ISIS synchrotron need to be removed for maintenance, it is not possible to use a crane and so the engineers use a specially designed hovercraft to move them

The dipole magnets that control the direction of the proton beam in the ISIS synchrotron occasionally need to be removed from the synchrotron hall for maintenance. During the current long shutdown, one of these dipole magnets was removed to replace both the coils inside it. The work has now been completed and it's time for it to return to the synchrotron hall.

To move these magnets, which weigh over 30 tonnes, is a challenging task, and one that is not possible using the cranes. The engineers use a hovercraft device that, thanks to its noise levels, is known as 'Hissing Sid'. Using a specially installed shiny floor, they are then able to use the control box to steer the unit using rubber wheels in the air cushion. They can then guide the magnet into the synchrotron hall, where the crane can lift it into place. 

1 November 2021

​A new interlocks system has been installed in the inner synchrotron that uses light curtains to cordon off areas that have already been searched by the crew. 

The new light corridorsThe group in front of the electronics rack

25 October 2021

With the completion of the Tank 4 build, the team are now reinstating the Linac roof shielding. This is the last part of the construction stage and so, when it is complete this will remove the additional restrictions in the area. reverting the building to normal operations.

team members with the crane replacing the linac shielding

18 October 2021

The magnet that is part of the series that directs the proton beam out of the accelerator is now back in the ring and under vacuum.

Magnet in the extracted proton beamMagnet in the extracted proton beam 

​4 October 2021

The images below show the services trolley in TS1, and how much it has been stripped back so far as part of the TS1 project. There is still several weeks of work until this stage is complete​. Spot the difference!! 

The target services area when fullThe target services area looking empty

22 September 2021 - extracted proton beam

​The mechanical work on one of the magnets that directs the proton beam out of the accelerator is complete (image, left); the next stage will be electrical testing when the magnet is in position. A mock up of the new collimator in the EPB has been constructed (image, right), to allow the team to ensure all components fit correctly and provide operational experience for team members.

An engineer tightening bolts on a magnet in the accelerator hallAn engineer inspecting the new collimator Mock up

22 September 2021 - Tank IV testing

The team have started the bead pull testing on the new linac tank IV. To find out more about this test, and how you can use a bead to replicate a beam, read our article on the testing they did before moving the tank

Computer screen showing bead pull testing

Ion source project, September 2021

As well as the major ongoing shutdown work on linac Tank 4 and TS1, significant preparatory work is happening behind the scenes for some projects due for installation in the next shutdown. One such project is the linac pre-injector upgrade. This is the section at the very start of the ISIS accelerator; when installed, it will bring big efficiency and performance improvements. A cutting-edge component of the pre-injector is the RF ion source, where the ion beam begins. The plasma inside the ion source was first switched on in April 2021 but only at low repetition rate, so the plasma appeared to flash on and off. In the months since, a technically-challenging cooling system involving 3D printed parts has been under test, with iteration toward a robust solution. Last week, the RF ion source achieved the milestone of operating at full repetition rate of 50 Hz whilst at full power. It is now flashing so fast that it appears by eye to be on constantly (see the red glow in image belo​w)! This achievement is significant because it demonstrates that the novel cooling system can remove the heat equivalent to a kitchen kettle from the volume of a drinks can. The next milestone of extracting an ion beam from the plasma is due around the new year. After that, long-term running will commence to prove the system is stable for eventual installation on ISIS. Congratulations to the Low Energy Beams Group on this achievement! For more information on the ion source project, watch Scott's introductory v​ideo

Plasma shown in the new ion source​​The low energy beams group

15 September 2021

As well as the TS1 and Tank IV projects, there are also a series of instrument upgrades taking place across the two target stations. The upgrades vary from the introduction of a flight tube under vacuum for Alfred, a new chopper for Sandals, a new chopper for LET and a new intermediate shutter for ChipIr that is being machined from steel removed from a pr​evious beamline, Carmen. 

ChipIr beamline with shiekding removedApprentice working on the new front end of SandalsNew chopper testing on LETSans2D beamline with shielding removed

10 September 2021

The six joints of the new tank IV have been vacuum leak tested and minor position adjustments of the drift tubes are now being conducted to account for any shifts that happened during transport. 

The new tank being vacuum tested

8 September 2021

As part of the TS1 project, the remote handling arms that are being used for the dissembly of the target services area, and removal of the reflectors, have themselves been repaired and replaced where neccessary.​

Jon using the remote handling armTwo engineers using the remote handling arm

27 August 2021

The TS1 project team have been adding covering plates to the parts that will make up the new beryllium reflector. These parts will assemble around the target like a 3D jigsaw.​ The plates are made from ‘boral’, a mix of aluminium and boron, with the boron being there as a neutron absorber. The plates are added to reduce the background signal of neutrons outside of the main pulse. 

21EC1675 TS1 workshop.jpg21EC1678 TS1 workshop (1).jpg

​24 August 2021

The cryogenics team have been busy repairing the large dilution fridge, which was distorted during high magnetic field testing.The images below show Alex and Ross soldering the pipes and then leak testing them. 

Alex and Ross soldering the dilution fridge pipesAlex soldering the dilution fridge pipesAlex leak testing the dilution fridge

18 August 2021

The old target was removed from TS1 after being packaged into a shielded flask. The video below shows how it was removed from the building, despite being too big to be lifted over the target assembly area. 

Jon using a trolley to move the target flaskThe target flask being lifted out of the tunnel

17 August 2021

A new 33T Dipole magent has been installed, and new coils put into one of the 18T Extraction Horizontal Bender magnets. ​

removing EHB3 out_Adrian Hooper.jpgEHB3 split coil removed_Adrian Hooper.jpgMoving Dipole 9_Adrian Hooper.jpg

11 August 2021

​The new tank ​IV sections have been lifted into place! 

Loading Tank Section_Adrian Hooper.jpgAll Sections In_Adrian Hooper.jpg

4 August 2021

Work continues to progress stripping out the target services trolley, with the last few remaining higher-radioactive dose items scheduled to be removed shortly. We are still working to resolve an issue with the service trolley’s movement, with the external company brought in to look at the drive-system due back to site next week to assist in fitting some upgraded parts. Progress with the remote handling work on the old TRAM has been impacted by additional work being required on TS2. This additional work was only discovered at the end of the last run so was not factored into the ​original TS1 planning. This work is needed to ensure TS2 is ready to take beam as part of commissioning the new tank IV​.​

21 July 2021

With the old tank removed, installation of the new tank has begun, starting with the rails that will support it. 

Installation of tank IV railsInstallation of tank IV rails

19 July 2021

The old tank IV was removed from the Linac area, using a complex arrangement of internal and external cranes. It has been installed in 1976, so this was a big moment! See below for a timelapse of the removal. 

Tank 4 on a craneTank 4 and the team

15 ​July 2021​

With the accelerator turned off, the work on the large engineering projects at ISIS have moved on to the next stage. In target station one, the current target assembly is being dissembled and removed. The first to be removed were the ion exchange columns (shown below); these components are now radioactive and need to be contained within flasks before removal. Ion exchange removal.jpg
​ 21EC1287 TS1 Ion exchange columns _ filter removal.jpg

Over in the linear accelerator, the old linac tank IV that is being replaced was prepared for removal (below, left). This is another engineering challenge, as the geometry to bring out the old tank in one piece was only just feasible, and the weight of the tank was close to the limit of the current crane. The new tank is also being taken apart again to prepare for installation (below, right). 

linac tank test lift

new linac tank stripped

Contact: de Laune, Rosie (STFC,RAL,ISIS)