Kurka, M.; Rudenko, A.; Foucar, L.; Kühnel, K.U.; Jiang, Y.H.; Ergler, T.; Havermeier, T.; Smolarski, M.; Schössler, S.; Cole, K.; Schöffler, M.; Dörner, R.; Gensch, M.; Düsterer, S.; Treusch, R.; Fritzsche, S.; Grum-Grzhimailo, A.N.; Gryzlova, E.V.; Kabachnik, N.M.; Schröter, C.D.; Moshammer, R.; Ullrich, J: Two-photon double ionization of Ne by free-electron laser radiation: a kinematically complete experiment. Journal of Physics B 42 (2009), p. 141002/1-5
10.1088/0953-4075/42/14/141002
Abstract:
We present kinematically complete data on two-photon double ionization of Ne induced by short (similar to 25 fs) intense (similar to 5 x 10(13) W cm(-2)) free-electron laser pulses at 44 eV. The observed electron energy spectrum points to the dominance of 'sequential' ionization. We analyse state-selective angular distributions as well as the two-electron angular correlation function, and suggest a method to determine the time delay between both ionization steps. The measured angular asymmetry (beta-) parameters significantly deviate from the results of an earlier non-coincident experiment providing benchmark data for theory.