Electron diffraction self-imaging of molecular fragmentation in two-step double ionization of water

• Published in: Physical review letters Vol. 106; no. 13; p. 133001
• Main Authors: Sann, H, Jahnke, T, Havermeier, T, Kreidi, K, Stuck, C, Meckel, M, Schöffler, M S, Neumann, N, Wallauer, R, Voss, S, Czasch, A, Jagutzki, O, Weber, Th, Schmidt-Böcking, H, Miyabe, S, Haxton, D J, Orel, A E, Rescigno, T N, Dörner, R
• Format: Journal Article
• Language: English
• Published: United States 29.03.2011
• ISSN: 1079-7114
• DOI: 10.1103/physrevlett.106.133001

We doubly ionize H(2)O by single photon absorption at 43 eV leading to H(+) + OH(+). A direct double ionization and a sequential process in which single ionization is followed by rapid dissociation into a proton and an autoionizing OH(*) are identified. The angular distribution of this delayed autoionization electron shows a preferred emission in the direction of the emitted proton. From this diffraction feature we obtain internuclear distances of 700 to 1100 a.u. at which the autoionization of the OH(*) occurs. The experimental findings are in line with calculations of the excited potential energy surfaces and their lifetimes.