High-resolution TEM observation of displacement cascades in krypton ion irradiated silicate minerals

Radiation induced amorphization (or metamictization) happens naturally in many U and Th containing minerals due to alpha decay of the radioactive actinides over the lengthy geological times. It has been shown recently that the process can be simulated very efficiently by ion beam irradiation. Detailed study at atomic level on this crystalline to aperiodic transition is necessary for the fundamental understanding of the process which is important to several technological fields, such as nuclear waste disposal and ionbeam modification of ceramic materials.

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High-resolution TEM study of ion beam irradiation induced amorphization in ceramic materials

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100138178 ◽

1995 ◽

Vol 53 ◽

pp. 360-361

Author(s):

L.M. Wang ◽

R.C. Ewing ◽

W.J. Weber

Keyword(s):

Ion Beam ◽

Alpha Decay ◽

Ceramic Materials ◽

Elastic Collision ◽

Target Atom ◽

Beam Irradiation ◽

Ion Beam Irradiation ◽

Fusion Neutron ◽

Displacement Cascade ◽

Material Science Community

Radiation damage of nuclear materials (e.g. fast- or fusion-neutron damage in reactor structural components, fission-fragment damage in nuclear fuels and alpha decay damage in nuclear waste forms) has been one of the major challenges faced by the material science community. Ion beam irradiation and implantation experiments have been used extensively in the past few decades not only for simulating these damaging process in materials but also for improving material properties for many technological applications.As an energetic particle traverses a crystalline target, it loses its energy predominantly through electronic (ionization) and nuclear (elastic collision) interactions with the atoms in the lattice. The target atom which receives sufficient energy from the interactions may get displaced from its lattice site and may further displace other target atoms, thus creating a displacement cascade which is usually a few nanometers in scale. Just at the end of the collision phase, which lasts for only a few tenths of a picosecond, a displacement cascade contains a very dense cluster of point defects and the region may be considered amorphous.

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Amorphization of ceramic materials by ion beam irradiation

Materials Science and Engineering A ◽

10.1016/s0921-5093(98)00715-1 ◽

1998 ◽

Vol 253 (1-2) ◽

pp. 106-113 ◽

Cited By ~ 19

Author(s):

L.M. Wang ◽

S.X. Wang ◽

W.L. Gong ◽

R.C. Ewing ◽

W.J. Weber

Keyword(s):

Ion Beam ◽

Ceramic Materials ◽

Beam Irradiation ◽

Ion Beam Irradiation

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Self-Radiation Damage in Actinide Host Phases of Nuclear Waste Forms

MRS Proceedings ◽

10.1557/proc-44-679 ◽

1984 ◽

Vol 44 ◽

Cited By ~ 6

Author(s):

W. J. Weber ◽

J. W. Wald ◽

Hi. Matzke

Keyword(s):

Radiation Damage ◽

Nuclear Waste ◽

Amorphous State ◽

Alpha Decay ◽

Ceramic Materials ◽

Thermal Recovery ◽

Radiation Induced ◽

Crystalline Ceramic ◽

Higher Doses ◽

Nuclear Waste Forms

AbstractThree crystalline ceramic materials, which occur as host phases for the long-lived actinides in many nuclear waste formulations, were doped with Cm-244, and the effects of self-radiation damage from alpha decay on microstructure and physical properties were investigated. The irradiation-induced microstructure consisted of individual amorphous tracks from both the alpha-recoil particles and the spontaneous fission fragments. The eventual overlap of the tracks at higher doses leads to a completely amorphous state. This radiation-induced amorphization process results in measured increases in volume, leachability, and stored energy. Thermal recovery of the radiation-induced swelling and amorphization occurs with full recrystallization to the initial structures.

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Radiation-induced implantation of polymeric films in metallic substrates

Journal of Materials Research ◽

10.1557/jmr.1986.0577 ◽

1986 ◽

Vol 1 (4) ◽

pp. 577-582

Author(s):

M.W. Ferralli ◽

M. Luntz

Keyword(s):

Film Formation ◽

Ion Beam ◽

Ion Beams ◽

Polymeric Films ◽

Beam Irradiation ◽

Ion Beam Irradiation ◽

Hydrocarbon Gases ◽

Metallic Substrates ◽

Radiation Induced ◽

Stage Process

Implanted, polymeric films have been produced by accelerator-ion-beam irradiation of metallic substrates immersed in hydrocarbon gases. Typical substrates include silver, aluminum, and steel; hydrocarbon gases include 1,3 butadiene and ethylene at 6.6 Pa pressure; ion beams employed include singly ionized H, He, and Ar at 30 keV. Experimental procedures and corrosion-resistance properties of the films are reviewed (each discussed elsewhere). A theory of the film-formation process is presented. It is concluded that the films form as the result of a two-stage process: glow-discharge adhesion and polymerization followed by radiation-induced implantation resulting from collisional recoil and substrate sputtering.

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Ion Beam Irradiation Effects on Polymers

MRS Proceedings ◽

10.1557/proc-792-r3.29 ◽

2003 ◽

Vol 792 ◽

Author(s):

Mircea Chipara

Keyword(s):

Experimental Data ◽

Free Radicals ◽

Energy Gap ◽

Ion Beam ◽

Beam Irradiation ◽

Irradiation Effects ◽

Ion Beam Irradiation ◽

Radiation Induced ◽

Main Effects

ABSTRACTThe main effects of the interaction of accelerated ions with polymeric targets are critically reviewed. The possibility of a relatively reduced heating of polymer during ion beam bombardment is analyzed. Experimental data pointing towards various radiation-induced modifications in polycarbonate (free radicals production, modifications of the energy gap) are discussed.

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