Isolated attosecond pulse generation in transition metal ablation plumes

Summary form only given. High-order harmonic generation (HHG) is a well-established route to the production of coherent XUV radiation and isolated attosecond pulses. In the pursuit to enhance low XUV harmonic flux from gas targets, and to study fundamental aspects of HHG, alternative media such as molecules, microdroplets, and solids have been employed. Especially, HHG in ablation plumes has attracted attention for high flux attosecond pulse generation [1]. This contribution focuses on HHG in plasma plumes generated from transition metals. These metals exhibit giant resonances in their photoionization cross sections (e.g. the Mn+ cross section is ~40 Mb at 50eV, compared with typical rare gas atom cross sections of 1 to 8 Mb at this photon energy [2]). Resonantly enhanced HHG has been confirmed by previous experiments with laser-produced transition metal plasmas [3] and also in a recent study with xenon gas [4].