| About this Abstract |
| Meeting |
MS&T22: Materials Science & Technology
|
| Symposium
|
Advanced Characterization of Materials for Nuclear, Radiation, and Extreme Environments III
|
| Presentation Title |
In-situ Thermal Diffusivity Recovery and Defect Annealing Kinetics in Self-ion Implanted Tungsten Using Transient Grating Spectroscopy |
| Author(s) |
Mohamed Abdallah Reza, Hongbing Yu, Cody Dennett, Kenichiro Mizohata, Felix Hofmann, Guanze He |
| On-Site Speaker (Planned) |
Mohamed Abdallah Reza |
| Abstract Scope |
Irradiation damage alters the properties of tungsten, the main candidate material for fusion reactor armor. Using transient grating spectroscopy with in-situ annealing, we study the recovery of thermal diffusivity in self-ion implanted tungsten up to 800C for doses from 0.00032 to 3.2 displacements per atom (dpa). Room temperature thermal diffusivity recovers from ~45% to 75% of the pristine value for the highest damage level. Using a kinetic theory model we interpret this recovery in terms of annealing of irradiation-induced defects. Our results show a large removal of defects at ~350C, consistent with the temperatures for mono-vacancy mobility in tungsten. This suggests that the small point defects, invisible to TEM, are the main contributors to thermal diffusivity degradation in room-temperature-irradiated tungsten. The defect recovery estimates also agreed well with TEM annealing experiments. These new results suggest that annealing at relatively modest temperatures may be used to reduce irradiation-induced thermal diffusivity degradation. |