Radiation induced defects in silicon at room temperature

ABSTRACTThe formation and stability of radiation-induced defects in structural materials in reactor environments significantly effects their integrity and performance. Hydrogen, which may be present in significant quantities in future reactors, may play an important role in defect evolution. To characterize the effect of hydrogen on cascade damage evolution, in-situ TEM self-ion irradiation and deuterium implantation was performed, both sequentially and concurrently, on nickel. This paper presents preliminary results characterizing dislocation loop formation and evolution during room temperature deuterium implantation and self-ion irradiation and the consequence of the sequence of irradiation. Hydrogen isotope implantation at room temperature appears to have little or no effect on the final dislocation loop structures that result from self-ion irradiation, regardless of the sequence of irradiation. Tilting experiments emphasize the importance of precise two-beam conditions for characterizing defect size and structure.

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High energy oxygen irradiation-induced defects in Fe-doped semi-insulating indium phosphide by positron annihilation technique

International Journal of Modern Physics B ◽

10.1142/s0217979217500199 ◽

2017 ◽

Vol 31 (04) ◽

pp. 1750019

Author(s):

S. Pan ◽

A. Mandal ◽

Md. A. Sohel ◽

A. K. Saha ◽

D. Das ◽

...

Keyword(s):

Indium Phosphide ◽

Positron Annihilation ◽

Room Temperature ◽

High Energy ◽

Average Lifetime ◽

Defect States ◽

Positron Trapping ◽

Radiation Induced ◽

Induced Defects ◽

Irradiation Induced Defects

Positron annihilation technique is applied to study the recovery of radiation-induced defects in 140 MeV oxygen (O[Formula: see text]) irradiated Fe-doped semi-insulating indium phosphide during annealing over a temperature region of 25[Formula: see text]C–650[Formula: see text]C. Lifetime spectra of the irradiated sample are fitted with three lifetime components. Trapping model analysis is used to characterize defect states corresponding to the de-convoluted lifetime values. After irradiation, the observed average lifetime of positron [Formula: see text] ps at room temperature is higher than the bulk lifetime by 21 ps which reveals the presence of radiation-induced defects in the material. A decrease in [Formula: see text] occurs during room temperature 25[Formula: see text]C to 200[Formula: see text]C indicating the dissociation of higher order defects, might be due to positron trapping in acceptor-type of defects ([Formula: see text]). A reverse annealing stage is found at temperature range of 250[Formula: see text]C–425[Formula: see text]C for [Formula: see text]-parameter probably due to the migration of vacancies and the formation of vacancy clusters. Increase in [Formula: see text]-parameter from 325[Formula: see text]C to 425[Formula: see text]C indicates the change in the nature of predominant positron trapping sites. Beyond 425[Formula: see text]C, [Formula: see text], [Formula: see text]-parameter and [Formula: see text]-parameter starts decreasing and around 650[Formula: see text]C, [Formula: see text] and [Formula: see text]-parameter approached almost the bulk value showing the annealing out of radiation-induced defects.

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Gamma radiation-induced defects in KCl, MgCl2, and ZnCl2 salts at room temperature

Physical Chemistry Chemical Physics ◽

10.1039/d1cp00520k ◽

2021 ◽

Author(s):

Alejandro Ramos-Ballesteros ◽

Ruchi Gakhar ◽

Gregory P. Horne ◽

Kazuhiro Iwamatsu ◽

James F. Wishart ◽

...

Keyword(s):

Gamma Radiation ◽

Gamma Irradiation ◽

Room Temperature ◽

Diffuse Reflectance ◽

Post Irradiation ◽

Radiation Induced ◽

Induced Defects

Room temperature post-irradiation measurements of diffuse reflectance and EPR spectroscopies were made to characterize the long-lived radiation-induced species formed upon gamma irradiation (up to 100 kGy) of solid KCl, MgCl2, and ZnCl2 salts.

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A STUDY OF STRESS RELAXATION RATE IN UN-IRRADIATED AND NEUTRON-IRRADIATED STAINLESS STEEL

Modern Physics Letters B ◽

10.1142/s021798490701258x ◽

2007 ◽

Vol 21 (05) ◽

pp. 295-301 ◽

Cited By ~ 1

Author(s):

I. M. GHAURI ◽

NAVEED AFZAL ◽

N. A. ZYREK

Keyword(s):

Stainless Steel ◽

Stress Relaxation ◽

Relaxation Rate ◽

Room Temperature ◽

Tensile Deformation ◽

Testing Machine ◽

Universal Testing ◽

Radiation Induced ◽

Stress Dependent ◽

Induced Defects

Stress relaxation rate in un-irradiated and neutron-irradiated 303 stainless steel was investigated at room temperature. The specimens were exposed to 100 mC, Ra-Be neutron source of continuous energy 2–12 MeV for a period ranging from 4 to 16 days. The tensile deformation of the specimens was carried out using a Universal Testing Machine at 300 K. During the deformation, straining was frequently interrupted by arresting the cross head to observe stress relaxation at fixed load. Stress relaxation rate, s, was found to be stress dependent i.e. it increased with increasing stress levels σ0 both in un-irradiated and irradiated specimens, however the rate was lower in irradiated specimens than those of un-irradiated ones. A further decrease in s was observed with increase in exposure time. The experiential decrease in the relaxation rate in irradiated specimens is ascribed to strong interaction of glide dislocations with radiation induced defects. The activation energy for the movement of dislocations was found to be higher in irradiated specimens as compared with the un-irradiated ones.

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Control of Radiation Induced Defects of Pure Silica Fiber Prepared by VAD Process

MRS Proceedings ◽

10.1557/proc-88-201 ◽

1986 ◽

Vol 88 ◽

Author(s):

K. Muta ◽

A. Kashiwazaki ◽

M. Kohketsu ◽

H. Kawazoe

Keyword(s):

Room Temperature ◽

Silica Fiber ◽

Sintering Process ◽

Porous Preform ◽

Pure Silica ◽

Radiation Induced ◽

Induced Defects ◽

Defect Species

ABSTRACTThe γ-induced centers in SiO2 glass such as the Si-E' center and OHC were found to be effected by the atmosphere present during melting. In the case of the VAD process, a porous preform rod is sintered to fabricate a transparent preform rod. The generation of defect species could be easily controlled by controlling the atmosphere of the sintering process. Only small amounts of OHC are generated in fibers sintered in Cl2 or H2 atmospheres, and most of the OHC is recovered at room temperature. This indicates the possibility of making fibers which are highly resistant to irradiation. The correlation between the γ-induced loss increase and the formation of these defects was examined.

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Microstructural Evolution of Radiation Induced Defects In ZnO During Isochronal Annealing

MRS Proceedings ◽

10.1557/proc-540-207 ◽

1998 ◽

Vol 540 ◽

Cited By ~ 8

Author(s):

S. Brunner ◽

W. Puff ◽

P. Mascher ◽

A.G. Balogh

Keyword(s):

Room Temperature ◽

Proton Irradiation ◽

Positron Lifetime ◽

Thermal Evolution ◽

Isochronal Annealing ◽

Doppler Broadening ◽

Thermal Dependence ◽

Radiation Induced ◽

Induced Defects ◽

Mev Protons

AbstractIn this study we discuss the microstructural changes after electron and proton irradiation and the thermal evolution of the radiation induced defects during isochronal annealing. The nominally undoped samples were irradiated either with 3 MeV protons to a fluence of 1.2× 1018 p/cm2 or with 1 MeV electrons to a fluence of 1×1018 e/cm2. The investigation was performed with positron lifetime and Doppler-broadening measurements. The measurements were done at room temperature and in some cases down to 10 K to investigate the thermal dependence of the trapping characteristics of the positrons.

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