ISOL-SRS (Isotope mass Separator On Line – Beam Storage Ring Spectrometer)


Shipping an OR66 4T MRI Magnet from the Wesley Hospital, Brisbane to CERN. This magnet will be used in the project.
(Credit: UK ISOL-SRS Collaboration)
Further information of shipping the magnet can be found here.

ISOLDE (Isotope mass Separator On-Line Device/facility) is one of the experimental infrastructures within the CERN complex of nuclear and particle physics experiments. The ISOL-SRS project is a major component of a wider European initiative that will exploit the heavy ion storage-ring facility, Test Storage Ring (TSR), to be installed at the HIE (High Intensity and Energy)-ISOLDE radioactive beam accelerator at CERN. The TSR will be transported from Heidelberg to CERN where it will be reconditioned.

ISOL-SRS is a joint collaboration between CERN, Germany, the UK and Belgium and will be a unique facility worldwide. ISOL-SRS will enable major breakthroughs in precision studies of the reactions and properties of unstable nuclei across the vast range of masses and isotopes. A fundamental part of the ISOL-SRS project is the construction of two spectrometers that will be used with the TSR. One of the spectrometers will be mounted inside the ring and the other mounted outside of the ring. These spectrometers will enable the whole range of radioactive nuclei to be studied. The nuclei produced at ISOLDE provide an interesting microscopic laboratory for high-precision measurements of beta decay, particle correlations and atomic masses. Studying short-lived radioactive nuclei at ISOLDE will help to understand how the elements from iron to uranium were created, which is one of the most intriguing scientific questions of the 21st century.

Quick Facts about the TSR


55.4m circumference


2 Dipole magnets
5 Quadrupole magnets
3 Sextupole magnets


An ion storage ring with one spectrometer mounted inside the ring and the other mounted outside of the ring. Radioactive nuclei are accelerated into the ring.

Quick Facts about the TSR Collaboration


Approximately 47 in 19 countries

UK Institutions



The Test Storage Ring
(Credit: Max Planck Institute for Nuclear Physics)

Science Challenges

The ISOL-SRS project is key to achieving STFC’s science challenges and hopes to help answer the following questions:

  • What is the physics of the early Universe?
  • What are the key reaction processes that drive explosive astrophysical events such as supernovae and X-ray bursts?
  • What are the fundamental particles?
  • What is the nature of nuclear matter?
  • What are the limits of nuclear existence?
  • How do the laws of physics work when driven to the extremes?
  • What can high energy particles tell us about the extreme Universe?

The UKs involvement

The UK’s ISOL-SRS project will provide the mechanics for the two spectrometers, detectors, readout electronics, and software for data acquisition and control. The only important deliverables that are not included in the UK’s part of the project is the installation of the TSR itself, the CERN beamlines, the gas jet target and the solenoid in which the external spectrometer will be housed. The UK is therefore playing a fundamental role in this project, and comprises of the Universities of Edinburgh, Liverpool, Manchester, surrey and York, and the Nuclear Physics group at STFC’s Daresbury Laboratory.

The UK currently plays a leading role in many of the experiments at ISOLDE and other facilities relevant to ISOL-SRS; these include coulomb excitation studies at REX-ISOLDE; laser spectroscopy at ISOLDE; and transfer and capture reactions, and nuclear isomer studies using the heavy ion storage ring at GSI. Funding ISOL-SRS allows the UK to play a key role in ISOLDE and maintain our world renowned scientific leadership in nuclear astrophysics, transfer reactions, coulomb excitation and laser spectroscopy. Furthermore, the UK will become a major shareholder in this exciting new facility with a rapidly growing international community.


The technology developed for studying key reactions and properties of nuclei, can be used to better the economy and social wellbeing of the UK. Liverpool, Daresbury and Edinburgh have strong links to industry which can lead to knowledge transfer and enable development of technologies that can be used in everyday life.

From the ISOL-SRS project, knowledge transfer may arise from the ultra-high vacuum environment in which the 4T magnetic field resides. The magnetic environment is very similar to that found in an MRI scanner. Therefore, experience of operating highly pixelated silicon detectors and their associated integrated ASIC electronics in strong magnetic fields could have benefits in the medical areas of combined PET/MRI or SPECT/MRI scanners, which could be used to detect tumours in the body.

Liverpool Festival of Science Technology

Liverpool Festival of Science Technology

Currently, Liverpool and Daresbury organise educational initiatives, including the Nuclear Physics Masterclasses for schoolchildren, and the Liverpool Festival of science technology. In addition to this, the ISOL-SRS project engages with a variety of general audiences from schoolchildren to the wider public. Nuclear physics, particle physics and astronomy are acknowledged as some of the key motivators for young people who decide to study Physics at university level. ISOL-SRS will inspire and invest in the next generation of scientists which is key to the future development of state-of-the-art technology.

Science and Technology Facilities Council Switchboard: 01793 442000