Ion sources and accelerators
The JANNuS- Saclay facility comprises three electrostatic accelerators (respectively named Épiméthée, Japet and Pandore) connected to a triple beam chamber for single-, dual- and triple beam irradiations. Two other chambers are linked to Épiméthée and Pandore for single beam irradiation and/or Ion Beam Analysis. The layout is divided into six linked rooms, separated by suitable concrete walls for radioprotection safety.
Épiméthée is a 3 MV single-ended electrostatic accelerator (3-UH-2 Pelletron, National Electrostatics Corp.) equipped with an electron cyclotron resonance (ECR) source (Pantechnik, Nanogan type) able to provide highly damaging beams with large energies and ranges, and also beams for IBA. The ECR source produces high charge states of a variety of ion species, which in combination with the 3 MV acceleration potential can produce ion beams with energies as high as 36 MeV. The source is equipped with four bottles for such gases as O2, He, Ar, Xe, CH4 and two cartridges of volatile organometallic compounds such as ferrocene and W(CO)6 for Fe and W ion production. Maximal intensities at the targets are for example 9.1014 pps (particles per second) for protons and He+, 6.1013 pps for Fe+ to 1,4.1011 pps for Fe11+, 1.1013 pps for W7+ to 1,4.1012 pps for W12+. Metal ions are produced by the MIVOC process. Fe8+ up to 24 MeV and W12+ up to 36 MeV are classically used to produce high damage levels up to 2 – 3 µm range with damage rate typically of the order of 10 dpa/h.
Japet is a 2 MV Tandem Pelletron (6SDH-2, National Electrostatics Corp.) equipped with an external SNICS II ion source (cesium sputter source) which can deliver electronegative ions such as Cl, I, C, Si, V, Cu, Zr, Ag, Au… This system is capable to produce energies of 0.5 to 4.0 MeV for single-charged ions, up to 6 MeV for double-charged ions, and correspondingly higher energies for ions of higher charge states. The SNICS-II source is naturally very efficient for halogen ions : chlorine and iodine. Yields for Cu, Au and Al are excellent. Si ions are also abundant. Ni, Ti and Zr ion beams have a quite satisfactory flux, but hardly above 14 MeV, 10 MeV and 12 MeV respectively. Weaker V, Ag and Nb beams can also be produced.
Maximal intensities are for example 3.2 1014 pps for protons, 4.1012 pps for V+ to 2.2 1011 pps for V5+, 1.75 1012 pps for Au3+ to 3.75 1011 pps for Au6+.
Pandore is a 2.5 MV single-ended electrostatic accelerator (7.5SH-2 Pelletron, National Electrostatics Corp.) equipped with a RF ion source. Six gas bottles are installed in the tank. Protons, deuterium ions, helium ions, nitrogen ions and Ar ions can be produced. This accelerator is used for implantation as well as for IBA. Maximal intensities are for example 1.2 1013 pps for protons and 5.5 1013 pps for 4He+.
Ions production :
The three accelerators offer a wide range of beams and more ions have still to be tested. Four gases and two metals are available on Épiméthée. Pandore produces different gases. Japet uses a single solid cathode that can be rapidly changed.