A monochromatic Fe beam is generated by heated supersonic expansion of argon seeded with Fe vapor. At a nozzle temperature of 1930 K and 800 torr argon inlet pressure the Fe beam has an axial velocity spread of 8% and intensity of 3 × 1015 s−1 sr−1, corresponding to a deposition rate of 10 nm/h at 150 mm from the nozzle. The two-chamber alumina crucibles are chemically stable for liquid Fe. With 400 mm3 Fe we have operated for more than 200 hours without reloading. The power consumption at 1930 K is 750 W. Temperature stability at constant power (without feedback) is better than 30 K. The source is intended for deposition of nanostructures by laser focusing of the Fe beam. The small axial velocity spread virtually eliminates the increase in focal spot size due to chromatic aberration.

This paper describes an optical investigation technique for visualizing the cross section of a vertical air stream flowing downward on a wet horizontal tube with moving liquid film. This method which associates the laser induced fluorescence and laser tomography techniques, uses Mie scattering tracers and fluorescent dye for marking the air and liquid flows, respectively. It allows us to visualize the air and liquid flows independently or simultaneously, and to measure the air flow separation angle. Results are compared with values obtained for a dry tube by the present and of other authors.

For thermal analysis, power module packages can often be considered as plane multilayered systems for which it has been demonstrated that appropriate Fourier transforms associated with the two-port network theory permit to develop very efficient solutions of the static or the time dependent 3D heat flow equation. However, in practice, the thermal resistances of soldered or pasted interfaces are most often not well known. Most of these parameters are theoretically unpredictable, therefore it is of highest interest to develop an experimental procedure intended for an adequate characterization of the 3D thermal behaviour of the cooling substrates. A two-port network theoretical basis for experimental characterization of the thermal behaviour of multilayered substrates (96% Alumina, AU4G, IMS), which are classically used for power module packaging, is presented. In spite of some difficulties in setting perfectly the boundary conditions for temperature and heat fluxes, the experimental results demonstrate the validity of the characterization method, and the soughted parameters can be measured for wide ranges of spatial pulsation. Suggested improvements of the existing experimental set can give rise to an industrial measurement set intended for thermal characterization of power module packages.