Experimental simulation and modeling by ion beams of alpha decay damage in apatite - Applications to thermochronology and to nuclear sciences for energy
Creators
- Cerico, Dee Jay
- Universite Paris-Saclay, Ecole doctorale no. 576, Particules, hadrons, energie et noyau, instrumentation, imagerie, cosmos et simulation - Pheniics (France)
- Faculte des sciences d'Orsay, Laboratoire de Physique des 2 Infinis Irene Joliot-Curie - IJCLab, Bat. 100 et 200, 15 rue Georges Clemenceau, 91405 Orsay (France)
Description
Apatite is a compound with applications in the fields of thermo-chronology and nuclear energy. Its natural mineral form can be used to reconstruct possible thermal histories of rocks while a synthesized apatite ceramic form can serve as a waste confinement matrix to immobilize actinides contained in spent nuclear fuels. For both applications, the amount of radiation damage created in apatite due to alpha decay events needs to be modeled and quantified. This thesis aims to investigate in a fundamental manner the kinetics of the following competing processes that determine the net amount of alpha decay damage in apatite: (1) buildup of damage considering the separate ballistic effects of alpha recoil nuclei and alpha particles emanating from alpha decay events; and (2) the athermal, ionization-induced recovery of pre-existing defects attributed to the electronic energy loss of alpha particles. The main techniques utilized in this study are in situ and ex situ ion implantation, Rutherford Backscattering Spectrometry (RBS/C), McChasy code, and Transmission Electron Microscopy (TEM). Experimental and simulation results strongly suggest that the kinetics of damage buildup in apatite irradiated with alpha recoil nuclei or alpha particles at 293 and 333 K could be described as a two-step process. The first step is a transformation from a near perfect crystalline structure to a partially-damaged one, while the second step, which is triggered after a certain ion fluence, results in a further structural transformation that could lead to a highly damaged state. Amorphization due to alpha recoil nucleus irradiation and helium bubble formation due to alpha particle irradiation are the two physical mechanisms that lead to rapid apatite crystal destabilization. With regard to ionization recovery, experimental results suggest that only certain types of defects such as amorphous clusters could be efficiently recovered by alpha particles and that point defects are likely less sensitive to this recovery effect. This means that alpha-particle induced recovery of defects does not occur or is likely insignificant for natural apatites with very low concentrations of uranium and thorium (few hundreds of ppm). (author)
Abstract (French)
L'apatite est un mineral aux nombreuses applications dans les domaines de la thermochronologie et de l'energie nucleaire. Le mineral peut etre utilise pour reconstruire l'histoire thermique de roches et les apatites de synthese sont envisagees comme matrice de confinement des actinides presents dans les combustibles irradies. Pour ces deux applications, il faut modeliser et quantifier l'endommagement cause par la desintegration alpha. Le but de cette these est l'etude fondamentale de la cinetique des processus concurrents qui determinent la quantite nette de l'endommagement dans l'apatite: (1) l'accumulation de degats en considerant les effets balistiques separes des noyaux de recul alpha et des particules alpha; et (2) l'effet du recuit athermique, induit par l'excitation electronique des particules alpha sur les defauts preexistants. Les principales techniques utilisees sont l'implantation ionique conduite in et hors situ, la spectrometrie de retrodiffusion Rutherford en geometrie de canalisation, le code de simulation McChasy et la microscopie electronique en transmission. Les resultats de cette etude montrent que la cinetique d'endommagement par les noyaux de recul alpha ou les particules alpha a 293 et 333 K peut etre decrite comme un processus en deux etapes et que l'amorphisation et la formation de bulles d'helium sont les deux mecanismes physiques qui conduisent a la destabilisation rapide des cristaux d'apatite. Seuls certains types de defauts comme les regions amorphisees peuvent etre recuit efficacement par l'excitation electronique des particules alpha alors que les defauts ponctuels y sont moins sensibles. Le recuit par ionisation est probablement insignifiant pour les apatites naturelles contenant de tres faibles concentrations en uranium et thorium (quelques centaines de ppm). (auteur)
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Additional details
Additional titles
- Original title (English)
- Simulation experimentale et modelisation par faisceaux d'ions de l'endommagement induit par la desintegration alpha dans l'apatite - Applications en thermochronologie et en sciences nucleaires pour l'energie
Publishing Information
- Imprint Pagination
- 248 p.
- Report number
- FRNC-TH--14839
INIS
- Country of Publication
- France
- Country of Input or Organization
- France
- INIS RN
- 54102344
- Subject category
- S36: MATERIALS SCIENCE;
- Resource subtype / Literary indicator
- Thesis
- Descriptors DEI
- ALPHA PARTICLES; ANNEALING; APATITES; ATOMIC DISPLACEMENTS; INTERSTITIAL HELIUM GENERATION; TIME DEPENDENCE
- Descriptors DEC
- CHARGED PARTICLES; HEAT TREATMENTS; IONIZING RADIATIONS; MINERALS; PHOSPHATE MINERALS; PHYSICAL RADIATION EFFECTS; RADIATION EFFECTS; RADIATIONS
Optional Information
- Notes
- 69 refs.; Available from the INIS Liaison Officer for France, see the INIS website for current contact and E-mail addresses