45 research outputs found
Energy window of Makrofol for alpha particle detection
© 2019 Elsevier B.V. Detection energy window of Makrofol detector irradiated with alpha particles and chemically treated by PEW (potassium hydroxide, ethanol, water) solution was investigated. Detectors were exposed to 241Am source through the cylindrical collimators in order to control incident alpha particle energies and angles. Alpha particles were detected in the wide energy range from 0.4 MeV to above 5 MeV. The dependence of track diameter on particle incident energy was also examined. Changes of etchant concentration and bulk etch rate (Vb) during two-hour etching were investigated. A slight increase of etchant concentration was observed while Vb was nearly constant during the whole etching process. Alpha particle passage through collimators with various dimensions and the corresponding energy distribution were also simulated theoretically using Monte Carlo Method and computer program written in Fortran90
History of radiological protection and evolution of dosimetric quantities
The paper presents a brief history of radiation protection and the evolution of radiation quantities. Special attention is given to the history of tissue weight factors. The internationally adopted system of radiation quantities is presented.Publishe
A computer program TRACK_P for studying proton tracks in PADC detectors
© 2016 The Author(s) A computer program for studying proton tracks in solid state nuclear track detectors was developed and described in this paper. The program was written in Fortran 90, with an additional tool for visualizing the track appearance as seen under the optical microscope in the transmission mode, which was written in the Python programming language. Measurable track parameters were determined and displayed in the application window and written in a data file. Three-dimensional representation of tracks was enabled. Examples of calculated tracks were also given in the present paper
Influence of electron motion in target atom on stopping power for low-energetic Ions
In this paper the stopping power was calculated, representing the electrons of the target atom as an assembly of quantum oscillators. It was considered that the electrons in the atoms have some velocity before interaction with the projectile, which is the main contribution of this paper. The influence of electron velocity on stopping power for different projectiles and targets was investigated. It was found that the velocity of the electron stopping power has the greatest influence at low energies of the projectile
RADIOACTIVITY ASSESSMENT OF NATURAL RADIONUCLIDES AND 137CS IN COMMONLY CONSUMED FOODS
The goal of this research is to determine the levels of natural and artificial radioactivity in 13
different samples of commonly consumed foods from Serbian markets. A gamma spectrometry was
used to measure the activity concentrations of 226Ra, 232Th, 40K, and 137Cs. The annual whole-body doses from 137Cs and natural radionuclides, due to the consumption of tea for an adult, are in the range of 2.3-8.5 nSv for 137Cs, 14.1 - 21.7 nSv for 232Ra, 18.4 - 73.6 nSv for 232Th and for 40K 10.4 - 22.9 nSv. These doses are not harmful to the general public's health.Publishe
Debugging of ORNL series of mathematical phantoms of human body
Series of mathematical phantoms of human body, given by Oak Ridge National Laboratory (ORNL), was programmed as input files for MCNP-4B code. Detailed check of geometry of these phantoms performed by MCNP-4B, discovered some minor errors, that resulted in overlapping of some organs. Three types of errors were found and described here: (a) colon overlaps with pelvis bone; (b) facial skeleton penetrate the head skin, and (c) esophagus overlaps with stomach. These errors prevent correct execution of program. Proposal for correction of these errors are given in this paper
Simple method for numerical solving of schroedinger equation for hydrogen atom in electric field
© 2018, Vinca Inst Nuclear Sci. All rights reserved. A propagation numerical method for determining energy eigenvalues and eigen wave functions for hydrogen atom in constant and uniform electric field is described in this paper. Solution is presented for 3-D Schroedinger equation in natural parabolic co-ordinate system. Criteria for accepting eigenvalues are introduced, and results are compared with previous papers
Alpha-particle fluence in radiobiological experiments
© The Author 2016. Two methods were proposed for determining alpha-particle fluence for radiobiological experiments. The first involved calculating the probabilities of hitting the target for alpha particles emitted from a source through Monte Carlo simulations, which when multiplied by the activity of the source gave the fluence at the target. The second relied on the number of chemically etched alpha-particle tracks developed on a solid-state nuclear track detector (SSNTD) that was irradiated by an alpha-particle source. The etching efficiencies (defined as percentages of latent tracks created by alpha particles from the source that could develop to become visible tracks upon chemical etching) were computed through Monte Carlo simulations, which when multiplied by the experimentally counted number of visible tracks would also give the fluence at the target. We studied alpha particles with an energy of 5.486 MeV emitted from an 241Am source, and considered the alpha-particle tracks developed on polyallyldiglycol carbonate film, which is a common SSNTD. Our results showed that the etching efficiencies were equal to one for source-film distances of from 0.6 to 3.5 cm for a circular film of radius of 1 cm, and for source-film distances of from 1 to 3 cm for circular film of radius of 2 cm. For circular film with a radius of 3 cm, the etching efficiencies never reached 1. On the other hand, the hit probability decreased monotonically with increase in the source-target distance, and fell to zero when the source-target distance was larger than the particle range in air
Updates to TRACK_TEST and TRACK_VISION computer programs
© 2021 by the authors. The computer programs TRACK_TEST and TRACK_VISION were previously developed to model profiles and optical appearances of tracks developed in solid-state nuclear track detectors. The programs were based on a track development model that involved the bulk etch rate Vb and the track etch rate Vt or the V function (i.e., Vt/Vb). The present work reported our work to update and modify these two programs. In the revised TRACK_TEST, two new V functions were added and enabled. Sample results for the CR-39 detector obtained using the three original and the two new V functions were compared. Discrepancies were within ~10% and 1 MeV, respectively. Another major revision of TRACK_TEST was to enable calculations for the Makrofol detector. In the revised TRACK_VISION, the two new V functions, as well as the option for the Makrofol detector, were also added. The experimental results on the Makrofol detectors were obtained (irradiated with 3.6-MeV alpha particles under normal incidence and then etched to achieve a removed detector thickness of 30 µm) for comparisons with the modeled results using the revised TRACK_VISION. The track diameters obtained from the experiment and model were 24.7 and 23.2 µm, respectively. Moreover, a bright area in the central parts, together with an outer dark ring, were present in both the simulated and experimental tracks. The track-opening diameters and the general optical appearances of the tracks were in good agreement