Imaging of radiation damage using complementary field ion microscopy and atom probe tomography.

Area of Science:

• Materials Science
• Nuclear Engineering
• Surface Science

Background:

• Tungsten and its alloys are critical materials for nuclear fusion reactors.
• Understanding radiation damage at the atomic level is essential for material longevity.
• Field ion microscopy (FIM) and atom probe tomography (APT) are advanced characterization techniques.

Purpose of the Study:

• To characterize radiation damage in tungsten and a tungsten-tantalum alloy.
• To demonstrate the synergistic strengths of combining FIM and APT for materials analysis.
• To investigate atomic-scale lattice damage and solute distribution.

Main Methods:

• Utilized Field Ion Microscopy (FIM) for atomic resolution imaging of crystal lattices.
• Employed Atom Probe Tomography (APT) for 3D analytical imaging with sub-nanometer resolution.
• Developed an indirect FIM method to chemically distinguish tantalum atoms in a tungsten matrix.

Main Results:

• FIM excels at imaging atomic-scale lattice damage, including single vacancies.
• APT data can show solute segregation and trajectory aberrations due to radiation damage.
• The combined APT-FIM approach successfully determined the atomic distribution of tantalum in a W-5at%Ta alloy.
• An indirect FIM technique enabled chemical distinction between tungsten and tantalum atoms.

Conclusions:

• Combining FIM and APT provides complementary insights into radiation damage mechanisms.
• FIM offers unparalleled resolution for visualizing the smallest manifestations of lattice damage.
• The developed indirect FIM method enhances chemical sensitivity for alloy analysis.
• These techniques are crucial for advancing materials development in nuclear fusion research.