DETERMINATION OF THE SINGLE INTERSTITIAL MIGRATION ENERGY FROM STORED ENERGY AND THERMAL RESISTIVITY CHANGES IN IRRADIATED GRAPHITE

Technical Report · Tue Jan 01 04:00:00 EST 1963

OSTI ID:4629291

Schweitzer, D G

The model used to evaluate the single interstitial migration energy from property changes due to interstitials is extended to account for vacancy contributions. The annealing function obtained can be used to determine the relative contributions of the defects and is sufficiently sensitive to distinguish vacancy effects that are an order of magnitude less than interstitial effects. Application of the model to stored energy and thermal resistivity data yields the same values of the activation energy and temperature independent term obtained from c-axis and macroscopic length expansion rates. The results indicate that the stored energy asso gamma ciated with di-interstitial is at least ten times greater than the stored energy associated with the vacancy. The minor role of vacancies in phonon scattering is discussed. Analysis of the annealing function obtained from electrical resistivity changes in irradiated graphite indicates that the ratios of charge carriers to scattering centers varies with irradiation temperature below 55 deg C. Above this temperature the changes are attributed to equal contributions from vacancies and interstitials. (auth)

• Research Organization: Brookhaven National Lab., Upton, N.Y.
• DOE Contract Number: AT(30-2)-GEN-16
• NSA Number: NSA-17-039662
• OSTI ID: 4629291
• Report Number(s): BNL-6809
• Country of Publication: United States
• Language: English

Related Subjects

DEFECTS
ELECTRIC CHARGES
EXPANSION
GRAPHITE
INTERSTITIALS
IRRADIATION
LATTICES
MATHEMATICS
METALS, CERAMICS, AND OTHER MATERIALS
PHONONS
SCATTERING
THERMAL CONDUCTIVITY
VACANCIES