Investigations of protons passing through the CR-39/PM-355 type of solid state nuclear track detectors.

Solid State Nuclear Track Detectors of the CR-39∕PM-355 type were irradiated with protons with energies in the range from 0.2 to 8.5 MeV. Their intensities and energies were controlled by a Si surface barrier detector located in an accelerator scattering chamber. The ranges of protons with energies of 6-7 MeV were comparable to the thickness of the PM-355 track detectors. Latent tracks in the polymeric detectors were chemically etched under standard conditions to develop the tracks. Standard optical microscope and scanning electron microscopy techniques were used for surface morphology characterization.

Surface morphology of unalloyed steels remelted with intense plasma pulses.

The set of unalloyed steels with various carbon concentrations were irradiated with intense plasma pulses with following process parameters: energy density 5 J cm(-2), pulse duration 2 mus, argon or nitrogen atmosphere. The energy density of each pulse was high enough to melt the surface layer of material. The cooling rate was estimated for 10(8) K s(-1) using the modelling method which takes into account heat evolution in the iron sample. Samples were characterized using the scanning electron microscopy technique for remelted surface morphology investigations. The tests with profilometer allowed us to investigate the changes of roughness of the surface layers.

Analysis of channel shapes in track membranes by scanning electron microscopy.

Control over pore geometry opens the way to a number of new applications of track-etch membranes (TMs). A special method of etching was developed to produce TMs with non-cylindrical pore profile. The direct observation of channel shape on fractures of track membranes was performed with a scanning electron microscope (SEM). The SEM images of the surface and cross-section of TMs with different pore morphology are shown. The channel diameter as a function of the depth below surface was measured and quantitative analysis was realized.

New methods of track membrane treatment in the preparation of samples for further observation with scanning electron microscopy.

Track membranes are porous systems consisting of a polymer foil with thin channels (i.e. pores) piercing it from surface to surface. The creation of non-cylindrical pores in a track membrane is important for the optimization of membrane characteristics, i.e. the highest productivity at the required selectivity. A new method of cleavage preparation (the irradiation of track membrane samples with accelerated electrons) for the observation of channel shapes directly in the membrane cross-sections is presented. Diagrams showing the tensile and burst strengths as a function of the irradiation dose, and images of surfaces and cleavages of track membrane samples are presented in this work. The changes in the pore sizes and shapes along the channel were clearly seen. These results can be used for the optimization of track membrane production.

Characterization of the near-surface layers of carbon steels modified by interaction with intense pulsed plasma beams: scanning electron microscopy investigations.

Modification of materials is a wide area in materials science, especially surface modification. To investigate the results of the modification process, treated and nontreated samples were compared. Intense plasma pulses of argon or nitrogen were used to irradiate the carbon steels. In all samples, the near-surface layer was melted. Results of scanning electron microscopy investigations of the surface morphology and cross-sections, as well as the results of tribological tests, are presented. The obtained results allowed us to draw conclusions about changes in material properties and to propose subsequent studies using other investigation techniques.