INTERSTITIAL-SINK ANNIHILATION AND INTERSTITIAL-VACANCY ANNIHILATION IN NEUTRON IRRADIATED GRAPHITE

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

OSTI ID:4126240

Schweitzer, D G

Various correlations of fractional macroscopic and lattice changes in neutron irradiated graphites are used to distinguish interstitial-sink reactions from interstitialvacancy reactions. The irradiation temperature dependence of the macroscopic expansion in the a'' direction is shown to be the same as the irradiation temperature dependence of the lattice expansion in the c'' direction and appears to reflect properties of interstitials. a'' spacing changes at different irradiation temperatures indicate that the rate of change of the lattice parameter in the a'' direction may be independent of irradiation temperature for low doses. The effect is consistent with the previously described model in which interstitials and vacancies are generated at a temperature-independent rate and supports the assumption that interstitials anneal to sinks during irradiation in lightly damaged graphite. Additional correlations of macroscopic and lattice changes with accumulated exposure can also be explained if interstitial-sink reactions predominate during the early stages of irradiation and interstitial-vacancy reactions become significant in heavily damaged graphites. Novel reverse c-axis annealing experiments are interpreted as independent evidence for the existence of interstitial-sink pairs that can be thermally decomposed at temperatures above their formation temperatures. (auth)

• Research Organization: Brookhaven National Lab., Upton, N.Y.
• DOE Contract Number: AT(30-2)-GEN-16
• NSA Number: NSA-18-004298
• OSTI ID: 4126240
• Report Number(s): BNL-6835
• Country of Publication: United States
• Language: English

Related Subjects

DECONTAMINATION
DEFECTS
EXPANSION
GRAPHITE
INTERSTITIALS
IRRADIATION
LATTICES
METALS, CERAMICS, AND OTHER MATERIALS
NEUTRONS
RADIATION EFFECTS
TEMPERATURE
THERMODYNAMICS
VACANCIES