CERN Accelerating science

European Organization for Nuclear Research

Neutron-driven element transmuter

Neutron-driven element transmuter


A beam of protons from a particle accelerator used to produce neutrons which are fired in an appropriate lead assembly. Neutrons bounce around inside the lead, losing a little energy with each bounce, such that the neutron spectrum covers a broad range of energies. Lead being the most transparent element to high energy neutrons has the advantage that these are not absorbed by lead, but much more efficiently by atoms of the sample to be transmuted. This enhanced neutron exposure may be used to produce useful radio-isotopes for medical use or, when using an opposite procedure to the one used for isotopes production, to transmute long lived isotopes such as those recovered from spent nuclear fuel.Applications

  • Transmutation of very long lived elements into stable, harmless elements.
  • Isotopes for medical use.

Area of expertise

Accelerators, Magnets and Cryogenic Technology

Innovative features

  • New types of isotopes for medical use such as Rhenium, Lutetium or Holmium.
  • New radio labeled elements for pharmaceutical use.

The technology has been applied for the development of new isotopes for brachytherapy treatment using accelerators, increasing the availability of new isotopes and allowing environmentally clean production. The efficiency of the production system is being tested for 188 and 186 Rhenium, 166 Holmium and 177 Lutetium. This application is available from Advanced Accelerator Applications.


  • High efficiency of transmuting long lived isotopes.
  • Efficiency in producing isotopes with accelerators.


  • Production of isotopes with no environmental risk.
  • Transformation of long lived isotopes into less harmful elements.


  • Efficiency of the method not established for many new potential isotopes.
  • Production cost to be evaluated.

Intellectual Property status

Two non exclusive licenses provided. Ready for further licensing. Patent granted in Europe, Bulgaria and Poland. WO9859347.

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