RADIATION DAMAGE IN GRAPHITE. IV. INTERSTITIAL REACTION KINETICS: COMPARISON OF THEORY AND EXPERIMENT

Technical Report · Mon Jan 01 04:00:00 EST 1962

OSTI ID:4651122

Schweitzer, D G

Interstitial cluster distributions and radiation formation and decomposition reactions are identified by fitting experimentally determined kinetic equations with calculations for consecutive reaction systems. Rate constants for the radiation decomposition of interstitial complexes are temperature independent and depend only on the neutron flux and the cross section of the complex. Rate constants for the radiation formation reactions of interstitial complexes all have the same temperature dependence. The results are consistent with the model described in other work in which immobile interstitial complexes are assumed to interact by addition and removal of mobile single interstitials. The total number of carbon atoms in the steadystate concentrations of interstitial complexes is the same in different species. The initial G/R function described in the preceding paper corresponds to reirradiations when single interstitials are not in steady state. The single interstitials reach steady state at the sarae time that the last of the intermediate species in the chain reach steady state. The second G/R function discussed in the previous paper describes dimensional changes when both single interstitials and interstitial complexes are in steady state. Anomalous radiation contraction and recovery hysteresis effects observed after reirradiations of 100 to 140 Mwd occur during the transition from non-steady state to steady state. The absence of annealing in the temperature intervals found in earlier discrete annealing experiments may be due to structural rearrangements (during reirradiations) of energetically unfavorable configurational isomers. (auth)

• Research Organization: Brookhaven National Lab., Upton, N.Y.
• DOE Contract Number: AT(30-2)-GEN-16
• NSA Number: NSA-17-036338
• OSTI ID: 4651122
• Report Number(s): BNL-6560
• Country of Publication: United States
• Language: English

Related Subjects

ANNEALING
ATOMS
CARBON
DECOMPOSITION
DEFECTS
DISTRIBUTION
GRAPHITE
HYSTERESIS
INTERACTIONS
INTERSTITIALS
ISOMERS
LATTICES
METALS, CERAMICS, AND OTHER MATERIALS
NEUTRON FLUX
NUMERICALS
QUANTITATIVE ANALYSIS
RADIATION EFFECTS
REACTION KINETICS
TEMPERATURE
VARIATIONS
VOLUME