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The work presents experimental measurements of electron beam transverse flux density distribution. Experimental data is recorded during the multiple beam scanning in different directions with the particular angle step by the thin scintillation strip. The intensity of the light generated in the scintillator is proportional to the intensity of the radiation going through the strip. Generated photons is guided by the optical fiber to the photomultiplier and registered by the analyzer. The result of the work is the experimental data demonstrated dependence of the radiation intensity on detecting strip position and angle orientation. This dependence is transformed to the radiation intensity dependence on the coordinates in the beam transverse plane using special mathematical processing.

Investigation purpose. Theoretical study of the depth dose measurements for therapeutic electron beam with longitudinally arranged dosimetry films in materials with different densities. Materials and methods. The work studies how the density of the medium, in which electrons propagate, affects the measured percentage depth dose and its reliability (PDD). For that, we calculate the distribution of the electron beam dose distribution in homogeneous materials with different densities and in a dosimetry film placed in materials with these densities. The density of material in the calculation varies from 0.4 to 2.3 g/cm 3 with a 0.1 g/cm 3 step. The coincidence of the PDD within the experimental measurement accuracy, that equals 4% for dosimetry film and 2% for measurements without it, is chosen as the data fitting criterion. Results. The PDD calculated for two geometries and for different media densities is the result of this work. The calculation shows that PDD difference is negligible when the density of the film is equal to the media one. With decreasing of the media density the difference appears in the regions of both shallow and great depth. The PDD is lower for the geometry with film than for geometry without it in case of these densities. When the media density is rising the opposite effect is observed: the PDD in the film is higher than in geometry without film. The maximum range and therapeutic range in both geometries coincide for the calculated curves throughout the range under study. Discussion. The work shows applicability of the investigated method for measurement of the electron beam percentage depth dose in media 1Corresponding author.

In this work we determines electron density using data obtained via CT scanner with one radiation source operating in two modes: with 80 kV and 120 kV voltage. We perform tomography study of calibration phantom with predetermined electron densities. Single linear relationship between energy-subtracted Hounsfield unit and relative electron density is determined. Using determined relationship the relative electron densities of phantom calibration samples is calculated. The comparison of calculated and nominal values proves the possibility of the samples relative electron density determination using energy-subtracted Hounsfield unit with error less than 2%.