This work is dealing with the understandingof the corrosion mechanisms at solid/solutioninterface and taking into account for the4He2+ions irradiation effects on these mechanisms.These corrosion and4He2+ions radiolysis phenomena append at solid/solution interface andwill be studied at a μmetric scale by the Raman spectroscopy. Moreover, a4He2+ionsirradiation affects a small low volume and allowsus to control the irradiated area (solution,solid or interface). For the solid,the chemical species induced by4He2+ions radiolysis ofwater are reactive and are involved inclassical corrosion mechanisms of UO2. Moreover, wewant to study the impact of the4He2+ions radiolysis of waterlayers physisorbed into thesurface onto corrosion mechanisms. That is thereason why we want touse a local irradiation,allowed by the4He2+ions ion beam provided by theARRONAX cyclotron (E = 64.7 MeV).In this work an experimental apparatus will be performed in order to characterizesolid/solution interface at μmetric scale by Raman spectroscopy under4He2+ions irradiationprovided by the cyclotron ARRONAX facility.The leaching experiments under irradiationwill be performed for a short time in order tostudy the parameters during the fast instantrelease step. The grain boundaries effect will be studied by the comparison between oneTRISO particles set (solids with grain boundaries) and one TRISO particles set previouslywashed by one acid solution (solid without grain boundaries). The role of H2will be studiedby the comparison between experiments under Ar or Ar/H2atmosphere. The dose rate rangewill be between 0 and 100 Gy/min by using the alpha ion beam which let us control the doseset down into the sample. For all these experiments, measurements will be performed by thein situRaman spectroscopy during the irradiation in order to follow theformation/consumption of the secondary phases formed onto the solid. The SEM will beperformed in order to characterize the grain boundaries and the secondary phases formed bythe leaching/irradiation experiments.The μGC is used to measure the PH2into the irradiationcell to follow the production/consumption of this gaseous species formed by the waterradiolysis and consumedby the leaching process.
