Dissertation
IMPROVING SCINTILLATION PERFORMANCE OF CE-DOPED GARNET CRYSTALS BY DEFECT ENGINEERING
Doctor of Philosophy (PhD), Washington State University
01/2010
Handle:
https://hdl.handle.net/2376/2793
Abstract
The ability to understand and modify defects behavior - "defect engineering" - is a key to unlocking the full performance potential of YAG (Yttrium Aluminum Garnet) and many other garnet scintillator materials. An effective original approach to defect treatment in garnet crystals was developed in this study. It is demonstrated that the dominant defect in Ce, Er codoped YAG scintillator crystals can be modified by a post growth treatment resulting in unprecedented performance improvement but a second defect, an antisite, remains. The next step in improvement of scintillation performance of garnet crystals was to develop a new host composition that does not form as many intrinsic defects and has better scintillation host characteristics along with added sensitivity to neutron radiation. Several compositions with promising characteristics were produced and tested. All crystals were grown using vertical gradient freeze technique with or without a seed crystal. The best results were obtained with YGGAG (Yttrium Gadolinium Gallium Aluminum Garnet) host material doped with Ce ions. This scintillator performs well with both photomultiplier tubes and Si-PIN photodiodes. Several host materials, such as GGG (Gadolinium Gallium Garnet) and YGG (Yttrium Gallium Garnet), did not demonstrate scintillator properties when doped with Ce ions. Reasons for such behavior are explained. Details of crystal growth, material properties and defects affecting scintillation performance are discussed.
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Details
- Title
- IMPROVING SCINTILLATION PERFORMANCE OF CE-DOPED GARNET CRYSTALS BY DEFECT ENGINEERING
- Creators
- Denys Solodovnikov
- Contributors
- Kelvin G Lynn (Advisor)Gary S Collins (Committee Member)Marvin G Norton (Committee Member)Matthew D McCluskey (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Materials Science and Engineering Program
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Number of pages
- 117
- Identifiers
- 99900581662501842
- Language
- English
- Resource Type
- Dissertation