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					Remon Ibrahim
 High Energy Group
   Content

 Introduction

 Experimental Techniques

 Results

 Conclusions
       Introduction
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
 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, Al2O3, ZrO2) in order to qualify them as candidates for inert
  matrix fuel.
    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.
      Experimental Techniques
                        Techniques


Microluminescence                             Laser confocal
                                           scanning microscope



         The material used is LiF irradiated with Xe
           ions with the energy 1.2MeV/nucleon
                                       Spectrometer


                                   8
1 – Specimen
                                                                    Digital
                                                                    Camera
2- Irradiated area                 7
3- Piezo stage (1 step – 100 nm)

4 - Base                           6
                                                                      Laser
5- Lens                                                           ex. = 473 nm

6 – Semitransparent mirror

7 – Filter
                                                      5
8 – Mirror Pinhole
                                                          2   1
                                                                           3




                                        4
        The experimental Procedure
        Xe ions   Measuring area




Ion Range




   LiF sample
        Spatial Resolution of optical system

Minimal size of analyzed area d=2.5 m for magnification 100.
d= (0.1- 0.2)×Rp    Rp - ion projected range

Photos of the stage micrometer for reflected light for different magnification
50 and 100. The distance between grooves – 10 m.




                                                  analyzed area
                                                      Results of the test measurements

                                                       Irradiated area
                                                                                                     Irradiated area Rp = 18 m




                                          50                                                                                     100




                                  50000
Photoluminescence signal , a.u.




                                                                                               Each peaks in this spectra represent
                                  40000
                                                                                               different types of F-center.
                                  30000
                                            x=3 m                       x=16 m
                                                                                               The peak at 530 nm corresponds to F3+
                                  20000
                                                                                               center while 670 nm corresponds to F2 center
                                  10000

                                                F+
                                                 3
                                                             F2
                                     0
                                      500       550    600   650   700    750      800   850
                                                               , nm
     F-

     Li+




               +-
               e              F Center

                    e-
                              F2 Center

                         e-




                              F3+Center

e-        e-
             Results of the test measurements


We measured the photoluminescence spectra at different depths for different fluences
of Xe ions




                                                         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
       Laser Confocal Scanning Microscope
 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.


                   We used LCSM with LiF samples and we get the same
                   depth profile as get by micro spectrometer
   Conclusion
 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.
     Acknowledgement

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.


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.

				
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posted:9/29/2012
language:English
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