Helium photoelectron angular distribution

Figure 5.13 Helium photoelectron angular distribution in the He+(2p) channel (logarithmic scale). x-Axis cosine of the electron ejection angle relative the laser polarization, y-axis total energy (1 a.u. 27 eV). (a) After the XUV-pulse after the IR-pulse for three different time delays, separated from each other by half the IR-pulse period, 15.53 fs (b), 16.87 fs(c), and 18.21 (d). The fringes in (b)-(d) arise due to the interference between the (XUV-pulse) direct ionization from the ground state and the (IR-pulse) ionization from the doubly excited populated by the XUV-pulse.

Figure 1.18 Example of the determination of the Stokes parameter S, and tilt angle X measured at 40 eV photon energy. It is based on an angular distribution measurement of ls-photoelectrons in helium for which equ. (1.55a) holds with P = 2. The arrows point to the measured values (with error bars, some of which are too small to be visible) the solid curve is a fit of the experimental data to this equation from which = 0.819(3) and...

Angular distribution parameters ft of photoelectrons Is photoionization in helium / = 2.0 (in dipole approximation)... 

Fig. 7.15. The photoelectron kinetic energy distribution following photoexcitation at 23.8 eV, below the ionization threshold at 24.6 eV, of large pure helium droplets N = 10 atoms. Most of the electrons leave the droplet with zero kinetic energy and have an isotropic angular distribution. ...

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