ABSTRACT
The rising use of radioactive elements is increasing radioactive pollution and calling for advanced materials to protect individuals. For instance, polymers are promising due to their mechanical, electrical, thermal, and multifunctional properties. Moreover, composites made of polymers and high atomic number fillers should allow to obtain material with low-weight, good flexibility, and good processability. Here we review the synthesis of polymer materials for radiation protection, with focus on the role of the nanofillers. We discuss the effectivness of polymeric materials for the absorption of fast neutrons. We also present the recycling of polymers into composites.
ABSTRACT
Low cost scintillation detectors as compared with HPGe detectors are considered to be one of most important radiation detection tools. Therefore, these detectors can be manufactured in different shapes and work at room temperature without any cooling systems, which added an extra advantage to it. This work presents a study of a cubic detector with a rectangular cavity in different experimental setup geometries, using standard point-like gamma-ray sources, where the efficiency of the detector in these geometries was the target to be studied. According to this aim, the data from the experimental measurements was used to determine the detector efficiency. An analytical calculation of the detector efficiency was done by using a new mathematical expression, this mathematical expression depends on the efficiency transfer technique and effective solid angle calculations. To support the mathematical model, the source-to-detector arrangement was simulated by Geant4 Monte Carlo code. All the compared efficiency results were found to be promising and trusted based on the calculated deviation percentages.
ABSTRACT
Scintillation crystals are usually used for detection of energetic photons at room temperature in high energy and nuclear physics research, non-destructive analysis of materials testing, safeguards, nuclear treaty verification, geological exploration, and medical imaging. Therefore, new designs and construction of radioactive beam facilities are coming on-line with these science brunches. A good number of researchers are investigating the efficiency of the γ-ray detectors to improve the models and techniques used in order to deal with the most pressing problems in physics research today. In the present work, a new integrative and uncomplicated numerical simulation method (NSM) is used to compute the full-energy (photo) peak efficiency of a regular hexagonal prism NaI(Tl) gamma-ray detector using radioactive point sources situated non-axial within its front surface boundaries. This simulation method is based on the efficiency transfer method. Most of the mathematical formulas in this work are derived analytically and solved numerically. The main core of the NSM is the calculation of the effective solid angle for radioactive point sources, which are situated non-axially at different distances from the front surface of the detector. The attenuation of the γ-rays through the detector's material and any other materials in-between the source and the detector is taken into account. A remarkable agreement between the experimental and calculated by present formalism results has been observed.
ABSTRACT
Gamma-ray detectors are widely used in many fields like environmental measurements, medicine, space science, and industry, where the detector geometrical, total, photopeak efficiencies and peak-to-total ratio could be required. The calculation of the detector efficiency depends mainly on the value of the geometrical efficiency, which depends on the solid angle subtended by the source-detector system. The present work introduces a direct analytical method to calculate the geometrical and total efficiencies of CdZnTe gamma-ray detector using off-axis isotropic radiating γ-ray [point, disk, and cylindrical] sources. To test the validity of the present work, the results are compared with some published data and also to prove how much it is important to determine the efficiency of difficult gamma-ray detection arrangement.
ABSTRACT
This work provides an empirical formula to calculate the FEPE for different detectors using the effective solid angle ratio derived from experimental measurements. The full energy peak efficiency (FEPE) curves of the (2â³(*)2â³) NaI(Tl) detector at different seven axial distances from the detector were depicted in a wide energy range from 59.53 to 1408keV using standard point sources. The distinction was based on the effects of the source energy and the source-to-detector distance. A good agreement was noticed between the measured and calculated efficiency values for the source-to-detector distances at 20, 25, 30, 35, 40, 45 and 50cm.
