Recent Results on K-Shell Ionization by Ion Collisions
The experimental K-shell ionization cross sections of 48Cd, 50Sn, 52Te, 53I and 56Ba for alpha particles, between 2.2 MeV and 2.8 MeV, and of 52Te for protons, between 1.6 and 3 MeV, are presented. The justification for making these measurements comes, on the one hand, in filling a region where, at present, data are sparse: for example, 52Te ionization cross sections by alpha particles have never been reported before, and, on the other hand, checking between previously reported and diverging sets of experimental results: for example, for alpha particles on tin. In addition, the K-shell ionization cross sections of 52Te for protons can be considered as an extension of Khelill's measurements.
K-shell ionisation by protons, deuterons and alpha particles at low projectile energies
The semiclassical approximation model (SCA) with hyperbolic projectile trajectories, including target recoil and symmetrisation, is used to study Coulomb ionisation in the incident energy range from 50 to 300 keV for a Ni target. Combined with corrections for the binding effect and the relativistic behaviour of the target electrons, the first-order SCA theory yields total cross sections consistent with recent measurements. No variation of parameters is performed.
Shape and surface texture of molten droplets deposited on cold surfaces
When a molten droplet impacts on a cold surface, the interaction between solidification and fluid dynamics can lead to different shapes and surface textures of deposited droplets. This article presents an experimental study on deposition of small droplets (39 μm diameter) of molten wax ink on solid surfaces. Our results show that both the final shape and the surface texture of deposited droplets are extremely sensitive to deposition conditions, which include initial temperature of droplets, type of substrate surface and distance between substrate and printhead. Different surface textures are observed and shown to depend on the thermal and flow histories of ink droplets during the process of impact. A test using crystalline wax reveals crystallization as one of the major factors in determining the final texture.