Radiation and Health Physics Group
Description: Radiation and Health Physics Group research Thermoluminescence (TL), Optic Situmulated Luminescence (OSL) dosimetry and radiation measurement and analysis.
TL&OSL dosimetry studies, are mainly involved the study of defects properties (i.e.defect models) and defect energy levels (i.e.trap depth) in a variety of insulating (LiF:Mg,Ti, CaF2:Dy) and wide-band gap semiconducting materials (ZnS), thermoluminescence kinetic mechanism, OSL&TL Dating, applications and development of new computer glow curve deconvolution (CGCD) programs. The experimental techniques employed involve optically or thermally stimulated luminescence (OSL &TL), phototransfer thermoluminescence (PTTL), emission spectrum (ES) and optical absorption (OA) measurements. These methods (especially OSL & TL methods) have applications in environmental dosimetry, personal dosimetry, high dose dosimetry, medical dosimetry, retrospective (accident) dosimetry, space dosimetry and archaeological dating.
We are particularly interested in solid state materials, the development of new materials and methods for use as radiation dosimetery using luminescence technique (Sponsored by Research Fund of Gaziantep University).
A second major interest within this lab is the development of new techniques based on the simultaneously application UV and thermal treatments on the dosimetric materials to stabilize their sensitivity changes after repeted reuse. Our recent work has resulted on the TLD-100 (LiF:Mg,Ti) and as a result it was found that this new method gives best result than older methods.
The another major interest in this lab is the application of OSL and TL luminescence dating procedures on quartz and feldspars (extracted from may arcological materials collected from around the Gaziantep City).
Our most recent interest has concerned the effect of various experimental parameters (i.e.heating rate, storage time, annealing temperature,...) on the trapping parameters (i.e.trapping depth, frequency factor,...) of TLD-100 and TLD-200. Further studies have also been continuing on these subjects for other type of dosimetric materials.
In our theoretical studies, we have also interested on the numerical modeling of the processes of TL and OSL production using mathematic programs (i.e. Mathematica and Mat-Lab). Numerical analysis of the rate equations describing the production of TL and OSL yield significant insight into the dynamics of the luminescence mechanisms. Based on this subject, we have investigated the effect of the temperature dependent frequency factor on the evaluated trapping parameters of TLD-100.
Radioactivity Measurement and Analysis studies is aimed that natural radionuclides concentrations and radioactivity values in industrial and natural resources are calculated. Using gamma spectrometry, radiation level of environmental and industrial samples measurements performed in the region. In addition, storage of the data obtained, and using this data to make a visual locations that cannot be measured by developing a computer program to predict the level of radiation, radiation mapping work carried out.
Ionizing and Non-ionizing Radiation Effect on the Matter Studies investigates effect of ionizing radiations X, γ, α, β and neutron etc. and UV and base stations emit non-ionizing electromagnetic radiation on matter and human health.
Thin Film Study Group
Description: Thin film group deals with deposition of thin films and investigation of properties of these thin films. This group specifies their studies by three deposition method; spray pyrolysis, chemical bath deposition and electrodeposition. Metallic (alloys and multilayers) and semiconductor films are grown by electrodeposition while spraying pyrolysis and chemical bath deposition are used for the growth of semiconductor films.
Spray pyrolysis and chemical bath deposition studies are served in thin film laboratory. In the thin film laboratory, we have a spectrophotometer, a chemical bath deposition system, a home-made spraying pyrolysis system, an oven, and the relevant electronic and temperature control units. II-VI compound semiconductors and III-V compound semiconductors thin films are deposited by these methods and influence of the deposition parameters on the structural, electrical, optical and thermoluminescence properties of the films are investigated. In recent years CdS, ZnS and
CdxZn1-xS semiconducting thin films were obtained by these two methods: chemical bath deposition and spray pyrolysis under different deposition conditions. The influence of the preparation technique on the structural, electrical and optical properties of the polycrystalline films were investigated. And also the influence of x composition on the films on structural, optical, thermoluminescence and electrical properties of sprayed and chemical bath deposited cadmium zinc sulfide (CdZnS) films were studied.
Electrodeposition is a method that uses electrical current to reduce cations on a conductive material to obtain a desired thickness of metal film. This group work on the investigation of the electrochemical properties, structural properties, morphological properties, corrosion properties and magnetic properties of the metallic (alloys and multilayers) films. Investigations on the magnetoresistance, electrical and optical properties of metallic films are also the main concern of this group. In the thin film laboratory, the group have a home-made electromagnet (>2T at 1.5cm gap), a home-made liquid nitrogen cryostat and a computer controlled electrodeposition system. Some specific studies of this group are on magnetic coupling and magnetic anisotropy in Fe/Co and Fe/Cu multilayers, magnetic studies on electrodeposited
Cu1-xCox alloy films, giant magnetoresistance of electrodeposited Cu-Co-Ni alloy films and some studies on electrodeposited
NixFe1-x alloy films. Recently Zn and Zn alloy (Zn-Mn) films are deposited by electrodeposition method onto steel plate substrate and the structural and the corrosion properties of these alloys are investigated in saline solution for the application as new friendly environmental sacrificial coatings in the protection of steel structures.
