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Missions and activities

The objective of this platform is to develop, to make and to characterize radioactive thin layers.

It was mainly developed for the needs for the community of data relating to the nuclear fuel cycle. The first studies thus concern actinides. However, other many needs appeared, in particular for the studies of the super-heavy elements, for the astrophysics or more widely for the studies of nuclear structure.

A building dedicated to CACAO was inaugurated in July 2013. Supplier’s authorization requests are under investigation with the Authority of Nuclear safety (ASN).

Physicist fills in the form and send it to :
A preliminary study is made by CACAO team and forwarded to the SPR (Department of Radiation Protection and Prevention), which validates the experimental protocol.

SKILLS & Equipment



This technique consists in depositing the radio element on a conductive surface. It involves to dissolve the radio element and obtain a conductive solution in which are placed two electrodes. The conductor support is the cathode. The adjustment of current/voltage leads to the deposition of radio - element on the cathode.

At this moment, the made thicknesses are between 4 and 400 µg/cm2 on a maximum diameter of 80 mm.
The advantage of this technique is to have a good theoretical yield (> 90 %) and able to adapt to all geometries conductor support. It must to adapt the cellwhich will use for electrodeposition according to the required target form.
However , a good knowledge of the chemistry of radio - element is essential so a strong interaction exists between radio chemists and CACAO team.
The disadvantage of this technique is not able to obtain a metal target. It contains oxygen, an unacceptable element for some physics experiments.(see R&D below).
The procceding of a development is as follows :

R&D on stable material or faintly radioactive material similar

  • dissolution
  • study of the backing
  • electrodeposition
  • caracterization

Manufacture of the radioactive layer

  • chemical separation
  • electrodeposition according to the developed protocol with the stable material or the faintly radioactive material similar
  • caracterization


This step allows to approve the quality of the made coats by an accurate measure of the quantity and the homogeneity of the coat and of their chimical and isotopic composition.

In the lab

  • alpha spectro
  • autoradiography
  • alpha wander
  • X-ray diffraction : DRX
  • Atomic Force Microscope : AFM
  • micro weighing


  • XPS to ICMMO
  • Ion Beam analysis : IBA (RBS, PIXE, NRA) to CSNSM


For the manufacture

CACAO works with radiochemical people. They are making a R&D on ionic liquids for the research which goes to the separation/transmutation of the actinides. With this technique, CACAO will make layers without oxygen.

For the caracterization

The ACTIV Project will allow to caracterize thin layers in watched area.

It is a secured multi-analysis chamber coupled with an accelerator.

This chamber, named C2ASCERA will allow to receive targets with a big diameter and to integrate ion beam analysis methods (RBS, NRA, PIXE) and a SEM/EDX.

The 2 important things are :

  •  not to contaminate the line which give the ions beam
  • to assure the containment of the material and the decontamination of the chamber and the different equipments.

The networks and european programs

  • INTDS : International Nuclear Target Development Society

This network gathers the comunity of targets (manufacture and characterization)

  • CHANDA : new CHAllenges in Nuclear DAta

The principal purpose is to reorganise the european community who works on the nuclear datas. IPNO is in chage of the WP "targets" dedicated to set up an european network to supply radio-elements and to make/characterize targets.




Institut de Physique Nucléaire Orsay - 15 rue Georges CLEMENCEAU - 91406 ORSAY (FRANCE)
UMR 8608 - CNRS/IN2P3

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