Remon Ibrahim Remon Ibrahim High Energy Group

 Introduction  Experimental Techniques  Results  Conclusions Content

Flerov Laboratory of Nuclear reactions (FLNR) FLNR carries out research in the field of heavy ion physics in three main directions Radiation effects and modification of materials The Irradiation Testing of Nuclear Ceramics and Oxides with Heavy Ions of Fission Fragment Energy Dr. Vladimir Skuratov, D.Sc Introduction Introduction

 One concept to reduce the environmental impact of radioactive waste, is the use of inert matrix fuels, which consist of a fissile phase embedded in an inert matrix phase.  Materials to be employed as inert matrices for transmutation of minor actinides should be resistant to radiation damages caused by fission fragments.  Such fission fragment-induced damage can be simulated by irradiation of swift heavy ions having the same stopping power.  The aim of this project is to study to radiation damage induced by swift heavy ions (E=1-3 Mev/amu) in several ceramics and single crystals (MgO, Al 2 O 3, ZrO 2 ) in order to qualify them as candidates for inert matrix fuel. Introduction Introduction

 One useful method to study the radiation damages is the optical spectroscopy, namely the photoluminescence technique.  In this technique the material is excited using light source and the light emitted from the material (luminescence) is monitored at the typical emission frequencies. The luminescence spectra may provide information about radiation defects in material. Introduction Introduction

Techniques Microluminescence Experimental Techniques Laser confocal scanning microscope The material used is LiF irradiated with Xe ions with the energy 1.2MeV/nucleon

Laser ex. = 473 nm Digital Camera Spectrometer – Specimen 2- Irradiated area 3- Piezo stage (1 step – 100 nm) 4 - Base 5- Lens 6 6 – Semitransparent mirror 7 7 – Filter 8 8 – Mirror Pinhole

LiF sample Xe ions Ion Range Measuring area The experimental Procedure The experimental Procedure

Minimal size of analyzed area d=2.5  m for magnification 100 . d= ( )×R p R p - ion projected range Photos of the stage micrometer for reflected light for different magnification 50  and 100 . The distance between grooves – 10  m. Spatial Resolution of optical system analyzed area

Results of the test measurements Each peaks in this spectra represent different types of F-center. Irradiated area 50  Irradiated area R p = 18  m 100  The peak at 530 nm corresponds to F 3 + center while 670 nm corresponds to F 2 center

+ e-e- F Center e-e- e-e- F 2 Center e-e- e-e- F 3 + Center Li + F-F-

We measured the photoluminescence spectra at different depths for different fluences of Xe ions Results of the test measurements The luminescence signal at highest ion fluences is registered mainly from the end-of-range region

Results of the test measurements Depth profiles of elastic (Sn) and ionizing (Se) energy losses This reflects the contribution of ionizing and nuclear energy losses in damage formation processes in LiF

 In most cases luminescence is sufficient to study the defects but in some cases more detailed is needed. This can be done using Laser Confocal Scanning Microscope.  This is a technique for obtaining high-resolution optical images with depth selectivity.  Images are acquired point-by-point and reconstructed with a computer, allowing three-dimensional imaging of objects. Laser Confocal Scanning Microscope We used LCSM with LiF samples and we get the same depth profile as get by micro spectrometer

 This work demonstrates how we can use photoluminescence spectra used to determine the defects induced by heavy ions (fission fragments).  Also, the photoluminescence spectra can be used to estimate the residual stress in solids caused by heavy ion irradiation using the shift of characteristic emission lines. Conclusion Conclusion

I wish to express my sincere gratitude to my supervisor Dr. Vladimir Skuratov. The supervision and support that he gave to me truly help the progression of my work. Acknowledgement Acknowledgement I sincerely thank other staff members who rendered their help during the period of my work. My special thanks to Tatiana and Nikita for their kind cooperation.