Transmission electron microscopy study of {alpha}-decay damage in aeschynite and britholite
- Univ. of New Mexico, Albuquerque, NM (United States)
The aeschynite structure-type (Ce,Nd,La,Th,U,Ca)(Nb,Ti){sub 2}O{sub 6}, and the rare-earth silicate apatite structure-type with the formula (Ce,La,Nd,Ca,Th){sub 10}(SiO{sub 4},PO{sub 4}){sub 6}(O,F,OH){sub 2} are important rare-earth and actinide host phases for high-level nuclear waste. Natural phases of these structure-types have calculated alpha-decay doses up to {approximately}10{sup 17} {alpha}-events/mg which have accumulated over hundreds of millions of years. Transmission electron microscopy has been used to study the microstructure of {alpha}-decay damage in aeschynite and britholite. Electron diffraction analysis of natural aeschynite revealed that minerals originally crystalline gradually lost their crystallinity with increasing alpha-decay doses. Helium bubbles were found in the aeschynite which have accumulated up to {approximately}2 {times} 10{sup 16} {alpha}-events/mg. These bubbles may nucleate within collision cascades during {alpha}-decay damage. Electron irradiation has an enhanced rare-gas migration and the formation of larger bubbles. High-resolution electron microscopy (HRTEM) revealed that amorphization during accumulation of {alpha}-decay damage was from alpha-recoil nuclei collision cascades, in both the aeschynite and britholite.
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- FG03-93ER45498
- OSTI ID:
- 572142
- Report Number(s):
- CONF-961202-; TRN: 98:003740
- Resource Relation:
- Conference: 1996 Fall meeting of the Materials Research Society (MRS), Boston, MA (United States), 2-6 Dec 1996; Other Information: PBD: 1997; Related Information: Is Part Of Scientific basis for nuclear waste management XX; Gray, W.J. [ed.] [Pacific Northwest National Lab., Richland, WA (United States)]; Triay, I.R. [ed.] [Los Alamos National Lab., NM (United States)]; PB: 1389 p.; Materials Research Society symposium proceedings, Volume 465
- Country of Publication:
- United States
- Language:
- English
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