Mohammad Nikoosefat; Ardeshir Bagheri; Hamid Reza Shakur; Zahra Shahbazi Rad; Nabi Javadi
Abstract
During the operation of Graphite -fuel HTGR (High-Temperature Gas-cooled Reactor) nuclear reactors, Graphite used as a neutron moderator, is irradiated and has a variety of contaminants (such as Cs-137, Co-60, and Sr-90) and due to industrial and environmental considerations, decontamination of ...
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During the operation of Graphite -fuel HTGR (High-Temperature Gas-cooled Reactor) nuclear reactors, Graphite used as a neutron moderator, is irradiated and has a variety of contaminants (such as Cs-137, Co-60, and Sr-90) and due to industrial and environmental considerations, decontamination of irradiated Graphite is very important. In this study, the decontamination of Cs-137 trapped in Graphite pores of Graphite -fuel (HTGR) nuclear reactors has been analyzed. The proposed method for decontamination of irradiated Graphite surfaces is the thermal plasma-sputtering method with noble feed gases, which are used to reduce the risk of radioactive Graphite waste and in this regard, a mathematical model was developed to describe the process of decontamination of irradiated Graphite, which is prone to release Wigner energy due to defects and torsion caused by radiation. The results show that the decrease in radiation pollution of irradiated Graphite waste and various parameters of its decontamination process depend on the release of Wigner energy. The results obtained are in good agreement with the other researchers results.
Ali Adeli Ahmadabadi; Zahra Shahbazi rad; Fereidon Abbasi Davani; Behjat Ghasemi
Abstract
In this research, the effect of ions produced in deuterium plasma on Tungsten (W) and Aluminum (Al) plates has been investigated using a plasma focus device with the specifications of (C=10.4 μF, V=23 kV, E=2.75 kJ). The W samples used because it is one of the key elements in the Tokamak device. Because ...
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In this research, the effect of ions produced in deuterium plasma on Tungsten (W) and Aluminum (Al) plates has been investigated using a plasma focus device with the specifications of (C=10.4 μF, V=23 kV, E=2.75 kJ). The W samples used because it is one of the key elements in the Tokamak device. Because we wanted to put the W samples at the distance from the anode top with maximum plasma produced ions, we should find the optimum place. Due to the high cost of W samples, we used Al samples to find the optimal conditions. The samples were irradiated at 8 cm distance from the anode top with deuterium ions produced by a plasma focus device. The sample analyses were done by the SEM and EDX methods. The sample irradiation by deuterium plasma ions caused a lot of damages and bubble formation on the sample surfaces. The analyses showed the extent of surface damage and the number of ions deposited on the surface. The number of damages on the Al surface was much higher than W. Bubbles were formed on the surface were due to the impact of deuterium ions on the W and Al samples. Also, the deuterium ion energy was measured with a Faraday cup as about 50 keV.
Yasaman Amiri; Behjat Ghasemi; Zahra Shahbazi-rad
Abstract
In this study , cold atmospheric pressure plasma jet used in treatment application was studied using COMSOL Multiphysics with the Finite Element Method . The device operates with argon gas at atmospheric pressure and by an alternating current power supply . Effective plasma parameters for treatment such ...
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In this study , cold atmospheric pressure plasma jet used in treatment application was studied using COMSOL Multiphysics with the Finite Element Method . The device operates with argon gas at atmospheric pressure and by an alternating current power supply . Effective plasma parameters for treatment such as electron density and electron temperature and electrical potential have been investigated . Plasma parameters that affect treatment were determined by establishing a virtual laboratory before the experiment . The electron density value is suitable for therapeutic applications and The plasma temperature is less than the amount that the tissue is damaged . The gas inside the jet is argon and the flow rate is 5 slm . the pressure of the dielectric barrier discharge type of plasma jet is kept 1 atmosphere . The frequency of the electrodes is kept constant at 25 kHz and their Maximum voltage at 9 kV .
