scholarly journals Radiation Chemistry of High-Energy Carbon, Neon, and Argon Ions: Integral Yields from Ferrous Sulfate Solutions

1981 ◽  
Vol 85 (3) ◽  
pp. 443 ◽  
Author(s):  
E. A. Christman ◽  
A. Appleby
Keyword(s):  
Ferrous Sulfate ◽  
Radiation Chemistry ◽  
High Energy ◽  
Sulfate Solutions ◽  
Argon Ions

Radiation Chemistry of High-Energy Carbon, Neon, and Argon Ions: Molecular Hydrogen Yields

1989 ◽  
Vol 118 (3) ◽  
pp. 401 ◽  
Author(s):  
A. Appleby ◽  
E. A. Christman ◽  
M. Jayko
Keyword(s):  
Molecular Hydrogen ◽  
Radiation Chemistry ◽  
High Energy ◽  
Argon Ions

scholarly journals Radiation Chemistry of High-Energy Carbon, Neon, and Argon Ions: Hydrated Electron Yields

1986 ◽  
Vol 106 (3) ◽  
pp. 300 ◽  
Author(s):  
A. Appleby ◽  
E. A. Christman ◽  
M. Jayko
Keyword(s):  
Radiation Chemistry ◽  
High Energy ◽  
Hydrated Electron ◽  
Argon Ions

The radiation chemistry of aqueous ferrous sulfate solutions at natural pH

1983 ◽  
Vol 36 (7) ◽  
pp. 1305 ◽  
Author(s):  
RW Matthews
Keyword(s):  
Hydrogen Atom ◽  
Ferrous Sulfate ◽  
Experimental Error ◽  
Absorbed Dose ◽  
Radiation Chemistry ◽  
Ion Concentration ◽  
Sulfate Solutions ◽  
Diffusion Controlled ◽  
Wide Range ◽  
Γ Rays

The yield of FeIII species has been determined in FeSO4 solutions irradiated at natural pH with 60Co γ-rays for a wide range of solute conditions. The stoichiometry of the hydrogen peroxide reaction was investigated and found to be abnormal if H2O2 is present in excess. If, however, FeS04 is present in excess, as it is in the irradiation of FeSO4 solutions, deviations from the normal stoichiometry are trivial. In nitrous oxide saturated solutions initial G(FeIII) values were found to be from 6.90 to 7.72 for FeSO4 concentrations in the range (0.5-2.0) × 10-3 M. Non-linearity in the yield of ferric ion concentration against dose plots was attributed to competition between hydrogen atom reduction of ferric species with hydrogen atom oxidation of ferrous species. The reaction between hydrogen atom and the ferric species was estimated to be close to diffusion controlled. In aerated solutions, the FeIII yield was, within experimental error, a linear function of dose for FeSO4 concentrations in the range (0.5 - 2.0) × 10.-3 M with G(FeIII) values of 12.27 ± 0.06, 12.62 ± 0.07 and 12.77 ± 0.10 for 0.5, 1.0 and 2.0 × M respectively. At lower FeSO4 concentrations. deviation from linearity was noticeable. The deviation was attributed to competition between FeII and FeIII species for the O2- radical anion. k(O2-· + FeII)/k(O2-·+ FeIII) was determined to be about 4.0. In deaerated solu- tion, the FeIII yield against absorbed dose for 1 × M FeSO4 solution was followed to extended doses. A limiting FeIII yield of about 0.75 times the aerated solution yield was observed in the closed system. The data were quite well described by values calculated from the reaction mechanism, published rate constants and the rate ratio of 0.016 for k(H· + FeII)/k(H· + FeIII) determined from the N2O experiments, and demonstrate the importance of reducing radical reactions with insoluble ferric species.

Radiation Chemistry of High-Energy Carbon, Neon, and Argon Ions: Hydroxyl Radical Yields

1985 ◽  
Vol 104 (3) ◽  
pp. 263 ◽  
Author(s):  
A. Appleby ◽  
E. A. Christman ◽  
M. Jayko
Keyword(s):  
Hydroxyl Radical ◽  
Radiation Chemistry ◽  
High Energy ◽  
Argon Ions

scholarly journals Modification of ethylene-norbornene copolymer by Gamma irradiation

2006 ◽  
Vol 60 (11-12) ◽  
pp. 311-315 ◽  
Author(s):  
Zorica Kacarevic-Popovic ◽  
Bojana Secerov ◽  
Milena Marinovic-Cincovic ◽  
Zoran Nedic ◽  
Slobodan Jovanovic
Keyword(s):  
Gamma Irradiation ◽  
Radiation Chemistry ◽  
High Energy ◽  
Spectrophotometric Analysis ◽  
New Combination ◽  
Polymeric Systems ◽  
New Class ◽  
Radiation Induced ◽  
Dsc Method ◽  
Induced Changes

The possibility of modifying polyethylene and many other polymers with high energy radiation has led to many useful applications. Due to their new combination of properties and the shortage of experimental data, the radiolysis of a new class of materials, cyclo-olefin copolymers (COC), polymerised from norbornene and ethylene using metallocene catalysts, is of great interest to the study of radiation chemistry and the physics of polymeric systems. Ethylenenorbornene copolymer, pristine and containing an antioxidant were subjected to gamma irradiation in the presence of air and in water. The irradiated copolymer was studied using IR and UV-vis spectrophotometric analysis. The radiation-induced changes in the molecular structure were correlated to changes in the glass transition temperature measured by the DSC method.

Direct Measurement of Ion Beam Induced, Nanoscale Roughening of GaN

2005 ◽  
Vol 864 ◽  
Author(s):  
Bentao Cui ◽  
P. I. Cohen ◽  
A. M. Dabiran
Keyword(s):  
Ion Beam ◽  
High Energy ◽  
Surface Relaxation ◽  
Surface Roughening ◽  
High Energy Electron ◽  
Force Microscopy ◽  
Atomic Force ◽  
Continuum Equation ◽  
Argon Ions ◽  
Nanoscale Patterns

AbatractThe formation of ion induced nanoscale patterns such as ripple, dots or pores can be described by a linear continuum equation consisting of a surface roughening term due to curvature-dependent sputtering or asymmetric attachment of vacancies, and a surface smoothing term due to thermal or ion-induced diffusion. By studying ion-induced dimple volume change using atomic force microscopy, we show a method to measure the ion-roughening coefficient. Using this method, we found the roughening coefficient í was 45 nm2/sec at 730K for initial ion etchings with 300 eV Argon ions. Cathodoluminescence measurements indicated Ga-vacancy formation during ion bombardment. The activation energy for surface relaxation after ion etching was about 0.12 eV as measured by reflection high energy electron diffraction.

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