The influence of five different chemical pretreatments on the optical properties of the Si surface was investigated by means of nulling ellipsometry. The ellipsometric data are fit to an air-SiO2-interface-Si model. The results of the experimental data interpretation show that thickness and structure of the "interracial layer" are changed drastically: the interracial layer thickness increases and the interracial layer optical properties approach the optical properties of crystalline Si. These changes in the interracial layer indicate the crystalline structure improvement of the substrate surface.

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Si(100) surfaces were modified by means of enhanced RCA procedure with “ HBF4-last” and “HF-last”. Nulling ellipsometric (NE) and secondary ion mass spectrometric (SIMS) measurements revealed that HBF4-treated Si surface is more strongly passivated by hydrogen and fluorine than HF-treated one: the oxidation rate of the HBF4-treated Si surfaces in air was found to be lower than that of the HF-treate surface. Scanning tunneling microscope (STM) images of HBF4-cleaned surface after 18 h storage in air were quite stable during observation, scanning could be easily performed over a wide area on every plot we chose.

The single cell irradiation using the tandem-type proton/ion accelerator is previewed for microdosimetry purposes in the biological media (yeast cells). Individual cells can also be targeted within a population to obtain the new in vivo data concerning a bystander effect. Usually the strong focusing systems are used for compression of the beam to µm diameter. In this work we assess the possibility to apply a simple mechanical collimator. The detailed modelling with MCNPX v.2.6 and GEANT4 v.9.1 codes shows that the 1.4-1.8 MeV proton beam energy deposition can be distributed in the 100 µm cell layer with a narrow collimator. An additional focusing system is needed for single cell irradiation. The method for calculation of the microbeam proton doses deposited in separate cells is prepared for the dose rate prediction in the 1.0-2.5 MeV proton and 3.5-3.7 MeV He 2+ ion energy range. The experimental proton beam measurements are performed and compared with modelling data.

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The comparison of sorption capacity of clinoptilolite and synthetic zeolites (zeolite NaX and zeolite NaA) in relation to the cesium in dynamic conditions was conducted. Dynamic conditions include multiple circulation of cesium containing solution through the sorbent layer. The mathematical modeling of sorption isotherms using the Langmuir equation, the Chebyshev criterion, and the least-squares method was conducted. Correlation of actual and model results indicates that the considered models adequately reflect sorption processes occurring in zeolites. The results of the study make it possible to use the considered models for predicting the behavior of zeolites in relation to cesium.

The possibility of cesium content evaluation by the particle induced X-ray emission method from X-ray emission L-shell at sorption from water solutions has been investigated. Consideration has been given to the processes of dynamic cesium sorption by zeolites from water solutions. The technique has been developed for preparing targets analyzable in the proton beam of energy up to 2.0 MeV. The relationship has been determined between the cesium content and the intensity of X-ray emission L-shell.