ISIS First Target Station Updates
30 Sep 2023



Last update 28 February 2024

The new TS1 target viewed through the remote handling cell

​​​​​​​The new TS1 target, reflector and moderator assembly. 


Update 28 February 2024

ISIS is now operational, including both target stations and, on the First Target Station, the methane and hydrogen moderator systems are running and all instruments are taking beam and running experiments.

Update 8 February 2024

​​ISIS is getting ready to run the upcoming cycle starting 13 Feb 2024.  The Second Target Station will be running as planned. On the First Target Station we have ongoing issues with the hydrogen moderator which require further remedial work. This will delay the start of the run cycle on TS1 by around 1 week. We apologise if this affects your experiment - instrument scientists will be in contact if this is the case.  We will give further updates as the TS1 moderator work progresses.


Update 24 Jan 2024

​​ISIS is in a planned shutdown until 13 Feb 2024. During this shutdown, work has been undertaken on the moderators on both target stations, particularly to fix the hydrogen moderator problems on the first target station (TS1). Updates on this work are given below. Both target stations are on track to begin operations ready for the user cycle on 13 Feb. 


  • The new hydrogen moderator has been installed and passed pressure & vacuum testing.
  • The methane moderator has been replaced as part of its regular maintenance cycle.


  • A new hydrogen moderator has been installed and successfully pressure & vacuum tested.
  • The methane moderator has also been replaced as part of its regular maintenance cycle. 

​Both programmes of work continue to progress on schedule, with commissioning for the moderator systems​ still to be performed once beam is reestablished early in February.


Update 3 Sept 2023

The last ISIS run cycle (26 June - 4 Aug) saw good running to both ISIS target stations. In particular, the methane moderator system on the first target station (TS1) ran well. The hydrogen moderator on TS1 is still not operational, meaning that Iris, Osiris, Surf and LoQ are not currently available.​

The issue with the hydrogen system has been diagnosed, and we anticipate that the moderator will be replaced during the ISIS Christmas 2023 shutdown, so that Iris and Osiris will be operational again from the new year.​

We are about to open the next proposal call for time on ISIS instruments. This call, with deadline 18 October 2023, will be for instruments on both ISIS target stations.  However, the quasi-elastic instruments Iris and Osiris will not be included in the call, as they have a large back-log of experiments due to the hydrogen moderator issues. ​

Update 1 June 2023

Commissioning work on the methane moderator system has continued, and although we have now had some periods of full beam to target, a few issues are still to be resolved.  During the current break between cycles, we are continuing to work on those issues.   We anticipate running full beam from the start of the next run cycle (27 June) but running may be intermittent over the first couple of weeks of the run cycle and so those instruments operating from the start of the cycle are likely to schedule UK users only over this period.  Your local contact will provide specific information in due course.

Instruments on the hydrogen moderator (Surf, LoQ, Iris, Osiris) will not be available until the Autumn at earliest.  Work is underway to address the hydrogen moderator problems.

We apologise for the continued delays to your programme. Our teams continue to work as hard as possible to establish reliable beam.  The ISIS student support for visits to overseas facilities​ remains in place for the moment.

If you are a user with questions about the scheduling of your experiment, please get in touch with your ISIS local contact. 

The ISIS Second Target Station (TS2) is fully operational.​

Update 3 April 2023

Over the past two years, the ISIS First Target Station (TS1) has undergone a major refurbishment, with the target, moderators and all associated services (water, cryogens, vacuum, etc) being completely replaced. This is a major project that will help to secure the future operations of the target station for many years to come. ​

Commissioning the new target station started in the Autumn of 2022, and we had planned that TS1 would be operational before the end of the year. The commissioning work identified several issues that have needed to be worked through, particularly with the moderator systems which involve complex cryogenic liquid handling. Although we have had the target station operating at full beam intensity and demonstrated the performance of the systems, we have not yet been able to achieve sustained neutron delivery to enable the start the user programme.  

We are still working to achieve consistent, full-intensity beam. Commissioning has continued to progress, with beam-to-target achieved over extended periods by the end of May 2023. Beam should be availble for user experiments from the start of the June / July 2023 run cycle (27 June); however, beam is likely to be more intermittant than normal over the first weeks of this run cycle, and so we are likely to schedule UK users over this period.

Unfortunately, difficulties with the hydrogen moderator mean that Iris, Osiris, LoQ, Surf and Crisp will be unavailable at that time. It is likely that these instruments will be unavailable until the autumn at the earliest, and it may be the new year before they are operational (this depends on the scope of work required to bring the moderator back into operations – this is currently being assessed). ​

We apologise for the delays to user science programmes on TS1. We know the effect this can have, particularly on student projects – our support for students who have experiments at other facilities overseas remains in place and we welcome applications for this. 

We will continue to provide updates as the work and schedule progresses. 

If you are a user with questions about the scheduling of your experiment, please get in touch with your ISIS local contact. 

The ISIS Second Target Station (TS2) is fully operational.

Contact: King, Philip (STFC,RAL,ISIS)