Nuclear Materials and Ion Irradiation Studies Using the JANNuS-Orsay In Situ Dual Ion Beam Transmission Electron Microscope

<i>In situ</i> Transmission Electron Microscopy (TEM) with ion implantation/irradiation is a key tool to investigate a wide field of topics, such as phase transition far from the equilibrium, solid-state nucleation/growth, defects recombination, and ageing of materials used in nuclear or space industries.<br/>In the 1980’s our laboratory was a pioneer in operating this kind of facility [1]. Thanks to this long experience, we were able to extend our <i>in situ </i>experimental potential to multiple simultaneous rastered beams, by building our first <i>in situ</i> dual ion beam TEM setup. Based on a 200 kV Tecnai G²20 Twin FEI microscope coupled with two ion accelerators [2], it offers a large choice of ions and energies (range from 10 keV to 6 MeV) and complementary analytical equipment (EDX, STEM, EELS, EFTEM) associated with different specimen holders (from LN₂ temperature up to 1000°C). Launched in 2009 as an open facility, it allows each year several worldwide teams through the EMIR&A French accelerators network [3] to process their <i>in situ </i>experiments.<br/>In this presentation, in the light of a selection of scientific results obtained throughout the past years, I will give an overview of the JANNuS-Orsay facility along with my own feedback as a local contact and scientific leader. Examples will be given on different materials studied for fission and fusion nuclear applications and submitted to extreme environments (irradiation, gas, temperature), and especially on recent results obtained on boron carbide [4], uranium dioxide [5] and steels [<i>e.g.</i> 6].<br/>The JANNuS-SCALP technical staff and the other local contacts (C. Baumier, S. Jublot-Leclerc) are all gratefully acknowledged for their unfailing assistance.<br/>[1] M.-O. Ruault, F. Fortuna, H. Bernas <i>et al</i>., J. Mater. Res. <b>20</b> (2005) 1758<br/>[2] A. Gentils, C. Cabet, Nucl. Instrum. Methods B<b> 447 </b>(2019) 107 ; http://jannus.in2p3.fr<br/>[3] https://emira.in2p3.fr<br/>[4] G. Victor, Y. Pipon, N. Moncoffre <i>et al</i>., J. of the European Ceramic Society <b>39</b> (2019) 726<br/>[5] Y. Haddad, L. Delauche, A. Gentils, F. Garrido, Nucl. Instrum. Methods B <b>435</b> (2018) 25<br/>[6] O. Emelyanova, A. Gentils, V.A. Borodin <i>et al</i>., J. Nucl. Mater. <b>545</b> (2021) 152724