Atomistic simulations of hypervelocity impacts: the tungsten case

DIPC Seminars

Speaker

Alberto Fraile
Bangor University, Nuclear Futures Institute

When

2023/11/15
12:00

Place

Donostia International Physics Center (Hybrid Seminar)

Host

Andres Ayuela Fernandez

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Controlling plasma-wall interactions is critical to achieve high performance in present day tokamaks, and will continue to be the case in the approach to practical fusion reactors. Tungsten (W) is the main candidate as plasma facing material for a fusion reactors and will be exclusively used in the ITER divertor [1]. Outstanding technical issues are still to be overcome, for instance erosion/redeposition from plasma sputtering and disruptions, dust and flake generation. The presence of high velocity impacts has been reported and suggested in several studies, with velocities being around 500 m/s to a few km/s [2, 3].
In this work, the atomistic mechanisms of damage initiation during high velocity (v up to 12 km/s) impacts of W projectiles on W has been investigated using molecular dynamics simulations, involving very large samples (up to 200 million atoms). Various aspects of the impact at high velocities where the projectile and part of the target materials undergo massive plastic deformation, breakup, melting or vaporization are analyzed [4-6]. Different stages of the penetration process are identified. A detailed comparison of our MD results and recent experiments will be presented.

References:
[1] G. Federici et al 2001 Nucl. Fusion 41 1967
[2] C. Castaldo et al 2007 Nucl. Fusion 47 L5–9
[3] S. Ratynskaia et al 2008 Nucl. Fusion 48 015006

[4] A. Fraile et al 2022 Nucl. Fusion 62 026034
[5] https://www.youtube.com/watch?v=NnioXy_eH-E

[6] https://www.youtube.com/watch?v=NpJ5G17LLqM

Zoom: https://dipc-org.zoom.us/j/96702310143
Youtube: https://youtube.com/live/hOzHd9wF3-o