High frequency beam oscillation keyhole dynamics in laser melting revealed by in-situ x-ray imaging oleh Ziheng Wu, Guannan Tang, Samuel J. Clark, Andrey Meshkov, Subhrajit Roychowdhury, Benjamin Gould, Victor Ostroverkhov, Thomas Adcock, Steven J. Duclos, Kamel Fezzaa, Christopher Immer, Anthony D. Rollett