Variational method for inner-shell excitation in heavy-ion collisions
In the framework of the monopole model we study a perturbation method for inner-shell excitation which covers the whole projectile velocity region. This is achieved by introducing a velocity-dependent variational parameter and minimizing the time-dependent perturbation. We apply the method to theK-excitation of nonrelativistic systems.
Angular Distribution of δ-Electrons Emitted in Slow, Asymmetric Heavy-Ion Collisions
The energy and angular distribution of electrons emitted from the K- and L-shell of relativistic atoms is evaluated in the semiclassical theory by means of the united-atom description. It is shown that for the high electron energies considered here the angular anisotropy is mostly small and has a dipole shape. For certain systems the electrons from the 2p1/2 and 2p3/2 subshells are preferably ejected in the backward direction. Detailed calculations are presented for the (S, Pb), (Ni, Pb) and (Pb, Sn) systems and compared with experimental data.
Continuous calibration of a vacuum ultraviolet system from 65 to 125 nm by a cascade arc and comparison with the calibrated line radiation of a hollow cathode.
A high-power stationary helium cascade arc has been developed as a standard source for continuum radiation in the VUV spectral range from 65 to 125 nm. The calibration of the VUV system response was based on the calculated and measured continuum radiation of a 2-mmphi pure He arc. Diagnostics of the arc plasma in partial thermal equilibrium yielded the electron density and the temperature that were inserted in the calculations of the continuous radiation. The results were compared with the helium, argon, and krypton radiation lines of a high-current hollow cathode lamp. This lamp was built according to the construction drawings of a hollow cathode, which was calibrated by means of the electron synchrotron radiation at the Physikalisch Technische Bundesanstalt Berlin.