SELF-DIFFUSION IN SINGLE-CRYSTAL TUNGSTEN AND DIFFUSION OF RHENIUM TRACER IN SINGLE-CRYSTAL TUNGSTEN

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1963

OSTI ID:4007470

Andelin, R L

Self-diffusion in single-crystal W and diffusion of Re tracer in single- crystal W were measured over the temperature range 2660 to 3230 deg C by the direct sectioning technique. The initial radioactive layers of W and Re tracers were produced on the diffusion samples by bombardment with 9.0-Mev deuterons. The tracers observed in determining the diffusion coefficients were /sup 185/W, / sup 183/Re and /sup 184/Re. Sample preparation and experimental techniques are described. The temperature dependence of the diffusion coefficients in the 2 systems was obtained by least-squares analysis. The results are consistent with a ring mechanism as the fundamental step in W selfdiffusion. It is reasonable to conjecture that Re tracer may diffuse through a W lattice by a similar mechanism. Total cross sections as a function of deuteron energy were measured for the reactions, /sup 184/W(d,p)/sup 185/W, /sup 186/W(d,p) /sup 187/W, and /sup 184/ W(d,2n) 34-day /sup 184/Re by the stacked-foil technique. Cross-section values for the reactions leading to the production of both /sup 185/W and /sup 187/W increased from about 3 mb at 6 Mev to a fairly broad maximum of 300 mb between 11 and 13 Mev. Cross sections for production of 34-day /sup 184/Re range from about 3 to 380 mb for deuterons with energies ranging from 7 to 14 Mev. The decay of / sup 185/W was observed over a period of about 9 half-lives, and a new half-life value of 75.14 plus or minus 0.63 days, with the uncertainty expressed to 3 sigma , was obtained. The half-life value obtained for /sup 187/W was 23.72 plus or minus 0.06 hours. (Dissertation Abstr., 24: No. 8, Feb. (1964))

• Research Organization: Originating Research Org. not identified
• NSA Number: NSA-18-021335
• OSTI ID: 4007470
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

CROSS SECTIONS
CRYSTALS
DEUTERON BEAMS
DIFFUSION
ENERGY RANGE
FOILS
HALF-LIFE
IMPURITIES
LABORATORY EQUIPMENT
LATTICES
LAYERS
LEAST SQUARES
MATHEMATICS
MEASURED VALUES
MEV RANGE
NEUTRONS
NUMERICALS
PERFORMANCE
PHYSICS
PREPARATION
PROTONS
RADIOACTIVITY
RHENIUM 184
TEMPERATURE
TUNGSTEN 183
TUNGSTEN 184
TUNGSTEN 185
TUNGSTEN 187