No abstract

Extensive studies of ion implantation into near surface areas of materials have demonstrated astonishing changes of such properties as surface tension, friction, and durability. The cost of implanted ions is currently rather high due to the limited ion current density of the usual ion sources, especially if ions from sources other than gaseous plasma must be used. The advent of the laser ion source, which offers many orders of magnitude higher current densities than classical ion sources, may change the scenario for a wide range of applications, making ion implantation as crucial a manufacturing technology in the future for other industries as it is today for microelectronics.

The amount and properties of ions produced by laser ablation of Ag targets have been analyzed. The maximum ion current density jmax=21.0 mA and maximum charge state Ar37+ of the ions produced by a laser power density of about 1×1014 W cm−2 at 1.315 and 0.657 μm on an Ag target have been determined. Direct implantation of the Ag ions from the laser-produced plasma has also been studied. An implanted ion density of 3.5×1016 cm−2 at a depth of 500 nm in Al samples was determined by RBS.

Results on iodine laser production of Ag, Au, Pb, Sn and Ta ions are presented and experiments on their implantation into steel, Al and plastics are compared and discussed. Ions were implanted without additional acceleration into metals to the depth of several hundreds of nanometers, and into plastics to a depths of up to several micrometers.

The very clean nuclear fusion reaction of hydrogen and boron-11 by inertial confinement arrives at conditions for power stations by volume ignition only at compressions to 100,000 times the solid state. The earlier (numerically) observed anomaly of decreasing gain at increasing density (retrograde behavior) is analyzed and the reason clarified: the strong stopping power mechanism, based on Gabor's collective model, is reaching its limit of too small Debye lengths at the extremely high densities because of the optimum temperature in the range of 30 keV due to the reabsorption of the bremsstrahlung. The relativistic correction of the bremsstrahlung for the always much higher temperatures after volume ignition is included from Maxon's model.