Laser-assisted XUV double ionization of helium atoms: Intensity dependence of joint angular distributions
Zhu Fengzheng1, 2, Li Genliang1, Liu Aihua1, †
       

Joint energy distribution of the two emitted electrons by an XUV pulse only is presented in (a) with peak intensity 1013 W/cm2. Comparisons of joint energy distribution for odd-parity electrons (b)–(d) and even-parity electrons (e)–(g) in different intensities of assisting-IR laser field: (b), (e) 1010 W/cm2, (c), (f) 1011 W/cm2, and (d), (g) 1012 W/cm2, where the peak intensity of the XUV pulses is 1013 W/cm2. The photon energy of the XUV laser field is 89 eV, and the assisting laser field is 1.61 eV. The pulse durations are 1 fs and 2.3 fs for XUV and assisting pulses, respectively.