Anti-Proton And Proton Impact Excitation-Ionization Of Helium Including Resonant Decay

The cross section for projectile impact excitation±ionization of helium is calculated, including spatial correlation, time-ordering, and interference between autoionizing and continuum states. The computational load is greatly reduced by using con®guration-interaction (CI) helium wave functions and continuum pseudostates, yielding a scattering amplitude that is a sum of analytical terms for the ®rst-order and energy-conserving second- and third-order contributions, and a one-dimensional integral for the energy-nonconserving second-order contributions. Comparison is made with experiment

Tomographic Analysis of SRF Cavities as Asymmetric Plasma Reactors

The tomographic reconstruction of local plasma parameters for nonequilibrium plasma sources is a developing approach, which has a great potential in understanding the fundamental processes and phenomena during plasma processing of SRF cavity walls. Any type of SRF cavity presents a plasma rector with limited or distorted symmetry and possible presence of high gradients. Development of the tomographic method for SRF plasma analysis consists of several steps. First, we define the method based on the inversion of the Abel integral equation for a hollow spherical reactor. Second step is application of the method for the actual elliptical cavity shape. Third step consists of study of the effects of various shapes of the driven electrode. Final step consists of testing the observed line-integrated optical emission data. We will show the typical results in each step and the final result will be presented in the form of correlation between local plasma parameter distributions and local etching characteristics