Structural response of SiC and PyC on swift heavy ion irradiation J.H. O'Connell1 ,E.J. Olivier1 and V.A. Skuratov2 1 Department of Physics, Nelson Mandela Metropolitan University, Port Elizabeth, South Africa 2 Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, Dubna, Russia Group for ion-implantation nanotechnology and radiation materials science

Examination of the dense ionization effect in ceramics and oxides with heavy ions of fission fragments energy The overall intention of this work is to yield sufficient basic data to determine and compare the radiation tolerance of several ceramics and oxide crystals considered as candidates materials for inert matrix fuel hosts using heavy ion beams of fission fragment energy. Inert matrices - ceramics with a high melting point and with low neutron absorption cross sections (MgAl2O4, MgO, Al2O3, ZrO2, SiC, ZrC, AlN, Si3N4) to be used as hosts for transmutation of actinides via nuclear reactions.

IC-100 FLNR JINR cyclotron. E  1.2 MeV/amu Experimental methods: In situ ionoluminescence measurements (to study the radiation damage and stress accumulation processes in swift heavy ion irradiated materials)

Experimental set-up for ion-beam-induced luminescence measurements on IC-100 FLNR JINR cyclotron In situ ionoluminescence measurements are used to study the radiation damage and stress accumulation processes in swift heavy ion irradiating materials

Role of SiC and PyC in TRISO (TRIstructural ISOtropic) Particle design

Examination of the dense ionization effect in ceramics and oxides with heavy ions of fission fragments energy Comparison of the low-magnification microstructures of SiC, AlN and Si3N4 irradiated with 31012 см-2 710 MeV Bi ions No evidence for track formation was obtained in SiC and AlN

Examination of the dense ionization effect in ceramics and oxides with heavy ions of fission fragments energy   Threshold ionizing radiation levels for track formation in ceramics AlN > 34 SiC > 34 Al2O3 > 41 Si3N4 15 MgAl2O4 8 Material Se, keV/nm High-resolution lattice image of Si3N4 irradiated with 710 MeV Bi ions (planar specimen)‏ S.J. Zinkle, V.A. Skuratov and D.T. Hoelzer. Nucl. Instr. Meth. 2002, B 191,1-4, pp. 758-766.

Examination of the dense ionization effect in ceramics and oxides with heavy ions of fission fragments energy 3D AFM image of of MgAl2O4 surface irradiated with 710 MeV Bi ions. Ion fluence 5x1010 cm-2. No surface damage associated with single ion impact, like observed on spinel, have been revealed in SiC

Examination of the structural integrity of constituent coating materials of triso fuel particles for use in generation IV HTGRs Work done at NMMU up until now is to study the structural response of SiC and PyC under irradiation by high energy neutrons as well as low energy light and heavy fission fragments. In addition the effects of radiation damage on metallic fission product diffusion through the coating layers are investigated. The main techniques employed in this research are: TEM (Transmission Electron Microscopy)‏ SEM (Scanning Electron Microscopy)‏ AFM (Atomic Force Microscopy)‏ Nano Hardness Measurements X- Ray Diffraction

TEM as method for evaluation of structural defects caused by radiation damage He+ BF XTEM micrograph of 6H-SiC implanted with 100 keV He+ with TRIM calculated damage and range overlayed.

TEM as method for evaluation of structural defects caused by radiation damage 200nm He+ BF XTEM micrograph of 6H-SiC implanted with 100 keV He+ showing strain contrast.

Proposed areas of collaboration between FLNR and NMMU Investigation of the structural response of SiC and PyC irradiated with swift heavy ions done at the FLNR as well as the role of swift heavy ions on the evolution of existing radiation induced damage. Study of the effect of swift heavy ions on the diffusion characteristics in SiC and PyC TEM and XRD examination of the accumulated stresses in various ceramics and oxides irradiated with swift heavy ions at the FLNR

Examination of the dense ionization effect in ceramics and oxides with heavy ions of fission fragments energy 240 MeV Kr, 300 K, ion fluence -1014 cm-2 Rp=18 m virgin Depth-resolved R-lines photoluminescence spectra measured in Al2O3:Cr using LCSM (laser confocal scanning microscopy) We aim to measure the average stress level by XRD and study microstructure by XTEM to find correlation between radiation damage and residual tress profiles

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